NZ727992B2 - Controlled release, wood preserving composition with low-volatile organic content for treating in-service utility poles, posts, pilings, cross-ties and other wooden structures - Google Patents

Abstract

This invention discloses a wood preservative composition for the supplemental or remedial treatment of in-service poles, posts, piling, cross ties and other wooden structures. The wood preservative composition comprises a slow-release micronized copper compound in combination with a boron compound or a fluoride compound.

Description

CONTROLLED RELEASE, WOOD PRESERVING COMPOSITION WITH LOW-VOLATILE ORGANIC CONTENT FOR TREATING VICE UTILITY POLES, POSTS, PILINGS, CROSS-TIES AND OTHER WOODEN STRUCTURES FIELD OF INVENTION This invention relates to wood preserving compositions for the supplemental or remedial treatment of wood in service, such as utility poles and railroad ties.

BACKGROUND OF INVENTION Wood and/or cellulose based products exposed in an outdoor environment are radable, primarily through attack by microorganisms. As a result, they will decay, weaken in strength, and discolor. The microorganisms causing wood oration include brown rots such as Postia placenta, hyllum m and Coniophora puteana, white rots such as Irpex s and Trametes versicolor, dry rots such as a lacrymans and Meruliporia incrassata and soft rots such as Cephalosporium, Acremonium, and Chaetomium. In on, wood is still subject to attack by wood-inhabiting insects, such as termites, beetles, ants, bees, wasps and so on.

Wood preservatives are well known for preserving wood and extend the service life of wood products including decking boards, fence posts, utility poles, railroad ties, permanent wood foundation, and other cellulose—based materials, such as paper, plywood, particleboard, textiles, rope, etc., against organisms responsible for the deterioration of wood.

Utility poles and railroad cross ties are wooden structures that are traditionally pressure treated with wood preservative chemicals, such as chromated copper arsenate (CCA), pentachlorophenol, copper naphthenate or creosote. Pressure treatment with preserving chemicals can certainly prevent y poles or railroad cross ties from fungal and termite attack and the pressure treatment can usually last for 30 to 40 years. However, the wood preserving als can only penetrate through most of the sapwood portion of the wood species and rarely penetrate the heartwood portion. This will cause insuf?cient treatment and insuf?cient al absorption.

In addition, improper treating ces may also cause poor treatment and insuf?cient al loadings. A direct consequence of the poor penetration and insuf?cient chemical loading is that, once the d utility poles are placed in service, often times a small percentage of poles show early failure and subsequent strength loss. As a result, a supplemental or remedial treatment is needed to offer the protection for those poles that show early failures. In older poles, the preservative als in the outer d zone will gradually e due to water leaching, ultraviolet degradation, chemical alteration or al damage. As a result, external decay or termite attack may p on the outer surface, and therefore there is an additional need for supplemental or al treatments to further extend the e life of aging utility poles and other wooden structures.

Preservative groundline treatments provide an economical extension to the useful life of utility poles. Experience has shown that groundline decay can be postponed almost inde?nitely in cases where periodic inspection and maintenance programs are in effect. External treatments on utility poles and other wooden structures are typically applied below the ground level either as pastes or grease~type compositions that are brushed on the wood surface, and then covered with a moisture resistant barrier, or as self-contained ready-made vative bandages.

In both cases, the goal is to supplement the original preservative treatment to prevent or arrest e decay. Protection is dependent upon the ability of the active ingredients to penetrate and remain in the treatment zone, and is limited to the depth of penetration. In addition, the composition must s satisfactory physical properties, such as viscosity, spreadability, nce, etc.

Historically, oilbome preservatives have been used for treating in-service utility poles and other wooden structures. Traditional oilbome preservatives included petroleum oils, te, copper naphthenate and pentachlorophenol. However, the use of oilbome mental preservatives is declining due to concerns of worker exposure to the organic solvents and leaching ofthe c solvents into the environment. Furthermore, the organic solvents, including No. 2 fuel oil, have recently experienced unprecedented price increases making them cost prohibitive for the manufacture of supplemental/remedial wood preservative compositions.

Current, known commercially ished preservatives for the after protection of in-service utility poles and other wooden structures contain copper or copper combined with boron and/or fluoride as their active biocides. Copper compounds, such as copper sulfate, copper carbonate and copper hydroxide, are generally known to be effective biocides as wood preservatives. Preferred copper compounds are generally insoluble and therefore must be solubilized to be effective in supplemental wood preservative compositions. This is typically accomplished by complexing the copper compounds with ammonia, acids or amines. Known copper complexes used in the ?eld of wood preservation e copper naphthenate, dispersible copper naphthenate, copper ethanolamine, ammoniacal copper citrate, ne copper quaternary and others. Sodium ?uoride and sodium borate are the most commonly used biocides in remedial preservative compositions. The sodium salts of boron and ?uoride are able to penetrate further through the wood structure due to their water solubility and mobility.

Although prior art compositions for the remedial treatment of utility poles and other wooden structures have been shown to be effective in extending the useful life ofwood products in—service, there are several problems that exist with current preservative compositions.

One limitation of using oil or water dilutable copper complexes is that they can readily leach from wood. Leaching of copper from wood can be further increased by the presence of oil solvents t in utility poles or cross ties from initial treatment with pentachlorophenol, creosote or copper naphthenate. ed re levels ly found within in-service poles and ties, particularly near or below groundline, can also increase the leaching rate of water dilutable copper complexes found in current vative paste itions.

The leaching of the copper component from current paste compositions is a concern from both a performance and environmental perspective. Depletion of the copper by leaching will ultimately compromise the long term bioef?cacy of the supplemental or al formulation, and the leached copper causes concern that the environment surrounding the treated structure will be contaminated. It has been established that copper is ely toxic to ?sh and other aquatic organisms at very low concentrations. Concerns over copper leaching from supplemental wood preservative compositions are such that their use is often limited or even restricted in areas of standing water or near water ways.

The uncontrolled mobility of the copper ent from current paste compositions is a further concern from a performance standpoint. Water soluble copper complexes e an uncontrolled dose to the Wooden structure to be ved by quickly dispersing beyond the intended zone of protection within the wooden structure and rapidly ing the copper reservoir contained within paste composition diminishing the ability of the treatment to provide prolonged periods ofprotection from the action of decay and wood destroying insects such as es.

In addition, the copper component of current supplemental wood vative compositions is not tive against some species of copper-tolerant wood decay fungi, often located in the Gulf-Coast region of the U.S. Generally, higher gs of copper are required in remedial compositions containing soluble forms of copper and/or a co-biocide is incorporated into the composition to afford protection t copper—tolerant decay fungi.

Finally, complexing copper to impart solubility can be expensive. Generally, high levels of the complexing agents are required to solubilize copper compounds. For example, 2 to 4 moles of a complexing or copper-solubilizing agent, such as monoethanolamine, for example, are required to complex 1 mole of copper. In the case of ammonia, 4 moles are required to complex 1 mole of copper. This can add considerable cost to the formulated remedial preservative compositions. In addition, oilborne copper naphthenate and other oil—based compositions lly require the use ofNo. 2 fuel oil as a r and are therefore extremely susceptible to large variations in cost.

Examples of supplemental or remedial preservative compositions for the afterprotection ofwood in-service can be found in the following literature.

U.S. Pat. No. 5,342,438 to West discloses a non-water dilutable remedial wood preservative containing copper derived from an amine-inorganic copper complex, combined with at least one sodium salt selected from the group consisting ofsodium borate and sodium ?uoride in a ratio of 2 to 120 parts of the sodium salt for each part of copper in the vative.

U.S. Pat. No. 6,110,263 to Goettsche teaches a process for the afterprotection of wood, which comprises treating the Wood with an effective wood ving amount of a wood preservative composition sing a copper compound, a polyamine or alkanolamine having at least two nitrogen atoms, and an inorganic fungicide, the treatment being effected by means of a bandaging process, an inoculation injection process, a borehole process or a paste process.

US. Pat. No. 5,084,280 to West claims a paste composition for preserving wood which contains as its only active wood vation ingredients a mixture of 10-90% by weight of a water-dispersible copper naphthenate and 90-10% by weight of borax.

US. Pat. No. 6,352,583 to che discloses a wood preservative for the supplemental protection of wood, consisting essentially of one or more copper compounds, one or more alkanolmonoamines and one or more complexing organic ylic acids or ammonium or alkali metal salts of said complexing organic carboxylic acids.

US. Pat. No. 6,306,202 to West teaches a water soluble ?xed copper-borax wood preservative composition which comprises a ?xed copper compound selected from the group ting of copper oxides, copper hydroxide, basic copper carbonate, basic copper sulfate, and copper oxychloride combined in water with sodium orate decahydrate wherein the ?xed copper nd concentration ranges from 0.01 parts to 0.20 parts for each part of sodium tetraborate decahydrate.

US. Pat. No. 8,221,797 to Zhang discloses a wood preservative ition for the supplemental or al treatment of in-service poles, posts, piling, cross ties and other wooden structures. The wood preservative composition comprises copper 8—hydroxyquinolate (oxine copper) in combination with a boron compound or a ?uoride compound wherein the copperquinolinolate is about 0.001% to about 2% by weight with a weight ratio of a boron or ?uoride compound of 1:1. The preferred form of oxine copper in this invention is a ?ne particulate, such that is found in dispersions through the milling process. Although it is not the most preferred, the composition ofthis invention can also be formulated into an oil-bome paste~ or grease-like formulation where the oxine copper is solubilized with an organic solvent.

This ion discloses a supplemental or remedial wood preservative composition which solves the ms identi?ed with current, known compositions and addresses the need for a more environmentally friendly technology for the afterprotection of vice wooden structures. This need is solved by the subject matter disclosed herein.

SUMMARY OF THE INVENTION The present invention provides an aqueous wood preservative paste composition comprising a dispersion of particles of a copper nd; a boron-containing compound; an aqueous carrier; and a thickening agent wherein the particles of the copper nd are present in an amount of about 0.001% to about 10% by weight of the composition. In one embodiment, the aqueous wood preservative paste composition is formulated to provide a controlled release of copper ions in a fungitoxic amount into an interior portion of the wooden structure.

The wood preservative ition of the present invention contain no more than about 36, 30, 20, 10, 5, 2 or 1 grams VOCs (volatile c compounds) per volume of the wood preservative coating. As used herein, the unit "grams VOC per volume of the wood preservative coating" means the mass (in grams) of VOCs per volume of a dehydrated wood preservative ition. In contrast, the mass VOC per volume of the wood preservative composition refers to the mass of VOCs per volume of the wood preservative ition, including the aqueous carrier. In one preferred ment, VOCs are not detectable by gas chromatography/mass spectrometry (GC/MS), according to EPA Method 8620, Volatile Organic Compounds by Gas Chromatography Mass Spectrometry (GC/MS). ' In one embodiment, the wood preservative composition is formulated as a thixotropic paste.

The wood preservative paste itions of the present invention are preferably formulated such that at least 20, 30, 40 or 50% of the particles of the paste composition se particles with diameters greater than about 25 microns. In another embodiment, the wood preservative compositions of the present invention are ably formulated such that less than , 15 or 20% of the les of the paste compositions comprise particles with diameters below about 100 microns. Conversely, the wood preservative compositions of the present invention are preferably formulated such that more than 80, 85 or 90% of the particles ofthe paste compositions comprise particles with diameters of about 100 microns or greater.

The wood preservative compositions of the present invention are produced by a method comprising the step of blending solid particles of a substantially insoluble copper nd comprising a particle size diameter between 0.01 and 25 microns; a boron—containing compound; an aqueous carrier; and a ning agent, to produce a paste composition with a viscosity of between 125 and 425 tenths of a millimeter (tmm) as measured using a penetrometer and, in a preferred embodiment, producing a paste ition wherein at least 20, 30, 40 or 50% of the les of the paste composition comprise particles with diameters greater than about 25 microns; wherein less than 10, 15 or 20% of the particles of the paste compositions comprise particles with diameters below about 100 microns; or wherein more than 80, 85 or 90% of the particles of the paste compositions comprise particles with diameters of about 100 s or greater.

In a preferred embodiment of the present invention, the solid particles of a substantially insoluble copper compound comprise a particle size diameter between 0.1 and 10 microns, more preferably beteween 0.1 and 5 s and most preferably between 0.1 and 2 microns.

The present invention also provides a method of delivering a fungitoxic amount of copper ion to an interior portion of a wooden product comprising. These methods comprise the step ofapplying an aqueous paste composition ofthe present invention to a wooden structure, such as a utility pole, pole, piling, railroad tie or other wooden ure, or the like. The application step may comprise brushing the aqueous paste composition onto the surface ofa wooden ure or other methods of applying a remedial treatment known in the art or described herein. In a preferred embodiment, the interior portion of the wooden structure is an interior region ofthe wooden structure extending from but excluding the surface of the wooden structure to about 1/4 inch from the surface of the wooden structure. In one ment, the fungitoxic amount of copper ions that penetrate the wood e and migrate to an interior portion of a wooden structure is about 0.04 pounds per square foot (PCF). In another embodiment, the fungitoxic amount delivered to an interior portion of a wooden structure is not more than 5, 10, 20, 30 or 50% greater than 0.04 PCF.

The wood preservative compositions disclosed herein may also optionally contain one or more organic biocides. In one embodiment, the c biocide is a fungicide, insecticide, moldicide, bactericide, or algaecide, or combinations thereof. In a red embodiment, the organic biocide is a quaternary ammonium compound, a le nd, an imidazole nd, an isothiazolone nd, or a pyrethroid compound, or combination thereof. In another embodiment, the organic biocide is imidacloprid, ?pronil, cy?uthrin, bifenthrin, permethrin, cypermethrin, chlorpyrifos, iodopropynyl butyloarbamate (IPBC), chlorothalonil, 2-(thiocyanatomethylthio) benzothiazole, alkoxylated diamines or carbendazim.

In a preferred embodiment, the boron—containing nd is a boric acid, a metal borate, a sodium , or a ium borate. In one embodiment, the sodium borate is sodium tetraborate decahydrate, sodium tetraborate pentahydrate, or disodium octaborate ydrate (DOT). In another embodiment, the metal borate is calcium borate, borate silicate, aluminum silicate borate hydroxide, silicate borate hydroxide ?uoride, hydroxide silicate borate, sodium silicate borate, m silicate borate, aluminum borate, boron oxide, magnesium borate, iron , copper borate or zinc borate.

The present invention also provides a supplemental or remedial wood preserving composition which comprises a copper compound combined with at least one boron compound or fluoride compound, or combinations thereof, which has good stability, low toxicity to animal and plant life and high biocidal activity against wood decay fungi and termites. The composition additionally comprises c fungicides and/or termiticides to further enhance the bio-ef?cacy.

The present invention also provides remedial paste compositions and methods for preservation ofwooden poles, railroad ties and other wooden structures against both fungal and termite attack and methods of treating wooden poles, railroad ties and other wooden structures with the wood preservative compositions ofthe present invention comprising the step of either dip or brush ation ofthe paste compositions onto and/or into the wooden poles, railroad ties and other wooden structures. In one embodiment, the methods for preservation en structures comprises the step of applying the remedial paste compositions of the t invention to cuts, holes or other injuries to previously pressure treated wood.

The present invention provides a preventive ent for standing wood utility poles, piles, lumber, timber, posts, ties and other exterior wooden structures including those ng in or in proximity to the ground that are susceptible to attack by decay and soft rot fungi, termites, carpenter ants, carpenter bees or wood boring beetles.

For prevention or control of exterior infestations in utility poles, piles, posts, and other wooden structures standing in the ground, excavate the soil away from the structure to a depth of 18 to 24 inches. Thoroughly clean and remove any decay or damaged wood from the treatment zone before ng the preservative. In one embodiment, the wood preservative compositions of the present invention are applied at rates from 1/16"to 3/8" thick to the area that is about 2" above ground line down to a depth of up to 24". In one embodiment, the application rate and treatment zone is dependent on the severity of condition, age and condition of the original preservative. In another embodiment, the treatment zone, after treatment, plus an area 2 inches above is covered with an impermeable moisture barrier.

.The invention also discloses a method for preparing a water-dilutable supplemental or remedial wood preserving composition which comprises either mixing, ng or milling the insoluble copper compound in water.

The wood vative itions of the present invention do not comprise one or more copper-solubilizing agents, such as ammonia, an ammonium salt, an amine, mono~ or polyalkanolamines.

The present invention also provides a method for preparing the wood preservative composition of the present invention comprising the step of maintaining the viscosity ofthe wood preservative composition between 275 and 425 tenths of a millimeter (tmm). In a preferred embodiment, the viscosity is maintained between 300 and 400 tmm. In a more preferred embodiment, the viscosity is ined between 320 and 340 tmm.The wood preservative compositions ofthe present invention comprise a copper compound that is substantially insoluble in the aqueous r. The copper or copper compounds such as cuprous oxide (a source of copper (1) ions), cupric oxide (a source of copper (II) ions), copper hydroxide, copper carbonate, basic copper carbonate, copper oxychloride, copper dimethyldithiocarbamate, copper e, copper , copper residues (copper metal byproducts) or any le copper source can be used.

These particles exhibit a relatively low lity in water. In a preferred embodiment, the copper compound is copper hydroxide, copper carbonate, or basic copper ate. In one ment, the wood vative composition comprises between about 0.001% to about 10% copper atoms by weight of the composition. In another embodiment, the wood preservative composition comprises between about 0.01% to about 2% copper atoms by weight of the composition. In a preferred embodiment, the wood preservative composition comprises between about 0.1% to about 1% copper atoms by weight ofthe composition. In a more preferred embodiment, the composition contains n 1 and 5% copper atoms by weight ofthe composition. In another red embodiment, the composition contains betWeen l and 3% copper atoms by weight of the composition. In preferred embodiments, the wood preservative compositions of the present invention contain between about 1 and 5%; about 1 and 3%; about 0.01 and 2% and about 0.1 and 1% copper atoms by weight of the composition.

In preferred embodiments, the wood preservative composition of the t invention do not comprise one or more copper-solubilizing agents, ing but not limited to ammonia, an ammonium salt, an amine, mono- or polyalkanolamines.

The copper nds le for the wood preservative compositions of the present invention are ntially insoluble in the aqueous carrier.

The boron-containing compound of the wood preservative compositions of the present invention are preferably boric acid, a metal , a sodium borate, or a potassium borate.

In a preferred embodiment, the sodium borate is sodium tetraborate decahydrate, sodium tetraborate pentahydrate, or disodium octaborate tetrahydrate (DOT). The metal borate is preferably calcium borate, borate silicate, um silicate borate hydroxide, silicate borate hydroxide ?uoride, hydroxide te , sodium silicate , m silicate borate, aluminum borate, boron oxide, magnesium borate, iron borate, copper borate or zinc borate. In one embodiment, the weight ratio of the boron compound to copper— is about 1 :1. In a preferred embodiment, the weight ratio ofthe boron compound to copper is about 10:1. In a more preferred embodiment, the weight ratio of the boron compound to copper is about 25:1. In the most preferred embodiment, the weight ratio of the boron compound to copper is about 50:1.

The wood preservative compositions of the present invention may further comprise a ?uoride-containing compound. In one embodiment, the ?uoride compound is sodium ?uoride, potassium ?uoride, calcium ?uoride, copper ?uoride, iron ?uoride, or magnesium ?uoride. In one embodiment, the weight ratio ofthe ?uoride compound to copper is about 1:1. In a preferred embodiment, the weight ratio of the ?uoride compound to copper is about 10:1. In a more preferred embodiment, the weight ratio of the ?uoride compound to copper is about 50:1. In the most preferred embodiment, the weight ratio of the ?uoride compound to copper is about 500:1.

In another embodiment, the weight ratio of the ?uoride nd to copper is between about 1:1 and about 500:1. In another embodiment, the weight ratio of the ?uoride compound to copper is between about 1:1 and about 50:1. In yet another embodiment, the weight ratio of the ?uoride compound to copper is between about 1:1 and about 10:1.

The wood preservative compositions ofthe present ion may further comprise one or more organic biocides. The organic biocides suitable for use with the t invention may include a fungicide, insecticide, moldicide, bactericide, or algaecide, or combinations thereof.

In another embodiment, the organic biocide is a nary ammonium compound, a triazole compound, an imidazole compound, an isothiazolone compound, or a pyrethroid compound, or combination thereof. In a red embodiment, the organic biocide is loprid, ?pronil, cyfluthrin, bifenthrin, permethrin, cypermethrin, chlorpyrifos, iodopropynyl butylcarbamate (IPBC), thalonil, 2—(thiocyanatomethylthio) benzothiazole, alkoxylated diamines or carbendazim. In one ment, the weight ratio ofthe organic biocide is about from 0.001% to % by . In another embodiment, the weight ratio of the organic biocide is about from 0.005% to 5% by weight. In yet another ment, the weight ratio of the organic biocide is about from of 0.01% to 1% by weight.

The wood preservative compositions of the present invention are prefereably formulated as pastes using an organic ner, an inorganic thickener or a combination of organic and inorganic thickeners. In a preferred embodiment, the organic thickener is cellulose-derived, such as a cellulose ester or a cellulose ether. Preferably, the cellulose ester is cellulose nitrate, sulfate, cellulose phosphate, ose nitrite, cellulose xanthate, cellulose acetate, cellulose formate or combination thereof. Preferably, the cellulose ether is methylcellulose, ethylcellulose, cellulose, cellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxybutylcellulose, cyanoethylcellulose, or carboxyethylcellulose. In one embodiment, the thickening agent is about 0.01 % to 50% by weight in the composition. In another embodiment, the thickening agent is about 0.5% to 10% by weight in the composition.

In a preferred embodiment, the inorganic thickener of the wood preservative compositions of the present invention is a clay. Preferably, the clay is attapulgite, dickite, saponite, montmorillonite, nacrite, kaolinite, anorthite, halloysite, lloysite, chrysotile, lizardite, tine, antigorite, lite, stevensite, hectonite, smecnite, nacrite, ite, montmorillonite, ite, stevensite, nontronite, saponite, hectorite, vermiculite, illite, te, glauconite-montmorillonite, roselite—montmorillonite, bentonite, chlorite-vermiculite, illite-montmorillonite, halloysite-montmorillonite, or kaolinitemontmorillonite. More preferably, the clay is attapulgi'te, hectorite, bentonite, montmorillonite, sauconite, smecnite, stevensite, beidellite, nite, saponite, hectorite, vermiculite, nacrite, or sepiolite. In one embodiment, the inorganic thickener is about 0.5% to about 30% by weight.

The wood preservative compositions of the present invention may also further comprise a drying retardant or a humectant, or both.

The wood preservative composition of the present invention may be packaged in containers, wraps, bandages and the like. In one ment, the container is a can, a bucket or a bag. In one embodiment the compositions ofthe present invention packaged in a container have a viscosity between 175 and 375 tenths of a millimeter (tmm). In a preferred embodiment, the viscosity is between 200 and 300 tmm. In a more preferred embodiment, the viscosity is between 210 and 250 tmm.

The present invention also provides a method for remedial treatment of wood, comprising the step of applying the composition of the present invention to wood. In a preferred method, the wood is an in—service wood product, such as a y pole, a railroad tie or wooden bridge. Preferably, the compositions of the present invention are applied by brush or spray.

Preferably, the composition is applied to wood to a thickness of between 1/32 and 3/4 inches. In a more red embodiment, the composition is applied to wood to a thickness of between 1/16 and NZ inches. In a most red embodiment, the ition is applied to wood to a ess of between 1/16 and 1/4 inches.

The boron-containing compound of the wood preservative compositions of the present invention are preferably boric acid, a metal borate, a sodium borate, or a potassium borate.

In a preferred ment, the sodium borate is sodium tetraborate decahydrate, sodium tetraborate pentahydrate, or um octaborate tetrahydrate (DOT). The metal borate is preferably calcium borate, borate silicate, aluminum silicate borate hydroxide, silicate borate hydroxide ?uoride, hydroxide silicate borate, sodium silicate borate, calcium silicate borate, aluminum borate, boron oxide, ium borate, iron borate, copper borate or zinc borate. In one embodiment, the weight ratio of the boron compound to copper- is about 1:1. In a preferred embodiment, the weight ratio of the boron compound to copper is about 10:1. In a more preferred embodiment, the weight ratio of the boron compound to copper is about 25:1. In the most preferred embodiment, the weight ratio of the boron compound to copper is about 50—: l.

The wood preservative compositions of the present invention may further comprise a ?uoride-containing compound. In one embodiment, the ?uoride compound is sodium ?uoride, potassium ?uoride, calcium e, copper ?uoride, iron ?uoride, or magnesium de. In one embodiment, the weight ratio ofthe ?uoride compound to copper is about 1:1. In a preferred embodiment, the weight ratio ofthe ?uoride compound to copper is about 10:1. In a more red embodiment, the weight ratio of the e nd to copper is about 50:1. In the most preferred embodiment, the weight ratio of the ?uoride compound to copper is about 500:1.

In another embodiment, the weight ratio of the ?uoride compound to copper is between about 1:1 and about 500:1. In another embodiment, the weight ratio of the e compound to copper is between about 1:1 and about 50:1. In yet another ment, the weight ratio of the ?uoride compound to copper is between about 1:1 and about 10:1.

The wood vative compositions ofthe present invention may further comprise one or more organic biocides. The organic biocides le for use with the present invention may include a ?mgicide, icide, moldicide, bactericide, or algaecide, or combinations thereof.

In another embodiment, the organic biocide is a quaternary ammonium compound, a triazole compound, an imidazole nd, an isothiazolone compound, or a pyrethroid compound, or combination thereof. In a preferred embodiment, the organic biocide is imidacloprid, il, cy?uthrin, bifenthrin, permethrin, cypermethrin, chlorpyrifos, iodopropynyl butylcarbamate (IPBC), chlorothalonil, 2—(thiocyanatomethylthio) benzothiazole, alkoxylated diamines or carbendazim. In one embodiment, the weight ratio ofthe organic biocide is about from 0.001% to % by weight. In another embodiment, the weight ratio ofthe organic biocide is about from 0.005% to 5% by weight. In yet another embodiment, the weight ratio of the organic biocide is about from of 0.01% to 1% by weight.

The wood preservative compositions of the present invention are prefereably formulated as pastes using an c thickener, an nic thickener or a combination of organic and inorganic thickeners. In a preferred embodiment, the organic thickener is cellulose—derived, such as a cellulose ester or a cellulose ether. Preferably, the cellulose ester is ose nitrate, sulfate, cellulose phosphate, cellulose nitrite, cellulose xanthate, cellulose acetate, cellulose formate or combination thereof. Preferably, the cellulose ether is methylcellulose, ethylcellulose, propylcellulose, cellulose, carboxymethylcellulose, yethylcellulose, hydroxypropylcellulose, hydroxybutylcellulose, cyanoethylcellulose, or carboxyethylcellulose. In one embodiment, the thickening agent is about 0.01% to 50% by weight in the composition. In another embodiment, the thickening agent is about 0.5% to 10% by weight in the composition.

In a preferred embodiment, the inorganic thickener of the wood preserVative compositions of the present ion is a clay. Preferably, the clay is attapulgite, dickite, saponite, montmorillonite, nacrite, kaolinite, anorthite, site, lloysite, chrysotile, lizardite, serpentine, antigorite, beidellite, stevensite, hectonite, smecnite, nacrite, sepiolite, montmorillonite, sauconite, stevensite, nontronite, saponite, hectorite, vermiculite, illite, sericite, glauconite-montmorillonite, r0selite-montmorillonite, bentonite, te-vermiculite, illite-montmorillonite, halloysite-montmorillonite, or kaolinitemontrnorillonite. More preferably, the clay is lgite, hectorite, bentonite, montmorillonite, ite, smecnite, stevensite, lite, nite, te, hectorite, vermiculite, nacrite, or sepiolite. In one embodiment, the inorganic thickener is about 0.5% to about 30% by weight.

The wood preservative compositions ofthe present invention may also further comprise a drying retardant or a humectant, or both.

The wood preservative composition of the present invention may be packaged in containers, wraps, bandages and the like. In one ment, the container is a can, a bucket or a bag. In one embodiment the compositions ofthe present invention packaged in a container have a viscosity between 175 and 375 tenths of a millimeter (tmm). In a preferred embodiment, the viscosity is between 200 and 300 tmm. In a more preferred embodiment, the ity is n 210 and 250 tmm.

The present invention also provides a method for remedial treatment of wood, comprising the step of applying the composition of the present invention to wood. In a preferred method, the wood is an vice wood product, such as a utility pole, a railroad tie or wooden bridge. Preferably, the compositions of the present invention are applied by brush or spray.

Preferably, the composition is applied to wood to a thickness of between 1/32 and 3/4 . In a more preferred embodiment, the composition is applied to wood to a thickness een 1/16 and 1/2 inches. In a most preferred embodiment, the composition is d to wood to a thickness of between 1/16 and U4 inches.

The present invention also provides a method for preparing the wood preservative composition of the present invention comprising the step of maintaining the viscosity of the wood preservative ition between 275 and 425 tenths of a millimeter (tmm). In a red ment, the viscosity is maintained between 300 and 400 tmm. In a more preferred embodiment, the viscosity is maintained between 320 and 340 tmm.

DETAILED PTION OF THE INVENTION Unless stated otherwise, such as in the examples, all amounts and numbers used in this speci?cation are intended to be interpreted as modi?ed by the term "abou ". Likewise, all elements or compounds ?ed in this specification, unless stated otherwise, are intended to be non-limiting and representative of other elements or compounds generally considered by those skilled in the art as being within the same family of elements or compounds.

As used herein, the term "micronized" means a particle size in the range of 0.001 to microns. As used herein, the term "particle size" means the largest axis of the particle, and in the case of a generally spherical particle, the largest axis is the diameter. Furthermore, it should be understood that "micronized" does not refer only to particles which have been produced by the finely dividing, such as by mechanical grinding, of als which are in bulk or other form.

Micronized particles can also be formed by other mechanical, chemical or physical methods, such as, for example, formation in solution, with or without a seeding agent, grinding or impingingjet.

The micronized copper particles disclosed in US. Publication No. 20050118280 are hereby speci?cally orated by reference, in their entirety.

As used herein, "copper-solubilizing agents" mean any agent that promotes the solubility of copper metal or a copper compound in an aqueous carrier. Copper-solubilizing agents include, but are not limited to ammonia and ammonium salts, , and alkanolmonoamines having between 2 to 18 carbon atoms, such as monoalkanolmonoamines, dialkanolmonoamines, and trialkanolmcnoamines, and m?tures thereof. Examples include monoethanolamine, diethanolamine, triethanolamine, 3-aminopropanol, monoisopropanolamine, obutanol, monomethylethanolamine, dimethylethanolamine, triethylethanolamine, monoethylethanolamine, N-methyldiethanolamine and mixtures thereof.

Disclosed herein is a supplemental/remedial composition for wood and a method for use thereof in treatment of in-service Wooden products, more particularly utility poles, railroad ties, wooden bridges. The composition comprises copper with a boron compound or ?uoride compound. The composition imparts to the treated wood resistance to both fungi and insects. The composition can additionally comprise an organic ide/termiticide.

In an effort to limit the level of volatile c compounds (VOCs) being released into the atmosphere and to minimize worker exposure, the Environmental Protection Agency (EPA) published the architectural gs rule on 1988 under ity of the Clean Air Act.

The e of this rulemaking was to reduce the VOCs d from architectural and industrial nance gs thus limiting the amount of VOCs that manufacturers can put in their products. Remedial preservative paste formulations are de?ned by EPA as architectural coatings and below ground wood preservatives. The VOC limit established by EPA for below ground wood preservatives is 550 grams of VOC per liter of coating. dual States such as Pennsylvania, New York and California (South Coast Air Quality Management District) have established a more stringent allowable VOC limit for below ground wood preservatives of 350 grams per liter of coating. The present invention provides compositions containing no more than 36, 30, 20, 10, 5, 2 or 1 grams volatile organic compounds (VOCs) per liter ofthe composition. In a preferred embodiment, VOCs are not detectable by gas chromatography/mass spectrometry (GC/MS). In r preferred embodiment, VOCs are not detectable by gas chromatography according to EPA Method 8620, le Organic nds by Gas Chromatography Mass Spectrometry (GC/MS), which is incorporated herein by reference in its entirety.

The compositions of the present invention have a broad spectrum of bio-efficacy against wood decay fungi, including, brOWn rot fungi, white rot fungi, and soft rot fungi.

Non~limiting examples of brown rot fungi include: Coniophora puteana, Serpula lacrymans, Antrodia vaillantii, Gloeophyllum trabeum, Gleoeophyllum ium, Lentinum lepideus, Oligoporus placenta, poria incrassate, Daedalea quercina, Postia placenta. Non-limiting examples of white rot fungi include: Trametes versicolor, Phanerochaete chrysosporium, Pleurotus ostreatus, Schizophyllum commune, Irpex lacteus. Some non-limited examples of soft rot fungi are Chaetomium um, ophora hoffmannii, ctys putredinis, Humicola alopallonella, Cephalosporium, Acremonium, and Chaetomium.

The compositions of the present invention are also effective against a broad range of insects and marine borer, including termites, beetles, and wood-boring insects. Non-limiting examples of termites include drywood termites such as termes and Kaloterms, and dampwood termites such as Zootermopsis, subterranean termites such as Coptotermes, ermes, litermes, rhinotermes, Microceroterrnes, Microtermes, and Nasutitermes. Non-limiting examples of beetles include those in families such as, for example, Anoniidae, Bostrychidae, Cerambycidae, Scolytidae, Curculionidae, Lymexylonidae, and Buprestidae.

The compositions of the present ion can be formulated into a waterborne paste- or grease- type of formulation, if desired, such that the formulation has an adhesive nature and is easy to apply to a desired location.

The present invention includes copper. The preferred form of copper for ation of the aqueous paste compositions of the present invention is a ?ne particulate, such that is found in dispersions h a milling process or the like. Methods for preparing milled substantially insoluble biocidal particulates that can be used in aqueous wood preservative compositions that can be applied to a wood product by vacuum and/or re treatment to effectively penetrate and preserve wood may be found in US. Pat. App. No.'s 20040258767, 20050118280 and 20060288904 to Leach and Zhang. The weight ratio of copper in the WO 95349 2015/034174 composition varies from about 0.001% to about 10% by weight. The preferred range of weight ratio of copper in the composition varies from about 0.1% to about 1% by weight.

The present invention also comprises a boron compound, a ?uoride compound or both. The boron compound can be either water soluble or water insoluble. Non-limiting examples of water soluble boron nds include boric acid, sodium borates, such as sodium tetraborate decahydrate, sodium tetraborate pentahydrate, and disodium octaborate tetrahydrate (DOT) and ium borates. Non—limiting es of water insoluble boron nds include metal borate nds such as calcium borate, borate silicate, aluminum silicate borate hydroxide, silicate borate hydroxide ?uoride, ide silicate borate, sodium silicate borate, calcium silicate borate, aluminum borate, boron oxide, magnesium borate, iron borate, copper borate and zinc borate.

Preferred boron compounds are water soluble boron compounds, such as boric acid and sodium tetraborate decahydrate, sodium tetraborate pentahydrate and disodium octaborate tetrahydrate (DOT).

The weight ratio of boron compound to copper can be in the range of from about 1:1 to about 500:1, the preferred weight ratio range is about 10:1 to about 200:1.

The present invention can also include a e compound. Non-limiting examples of ?uoride compounds include sodium ?uoride, potassium ?uoride, calcium ?uoride, copper ?uoride, iron ?uoride, magnesium ?uoride, and other metal compounds of ?uoride. The preferred es are sodium ?uoride and potassium ?uoride. The weight ratio of ?uoride compound to copper can be in the range of from about 1:1 to about 1000:1, the preferred weight ratio range is about 10:1 to about 200:].

The present composition optionally comprises one or more combinations of a organic biocides, such as nary ammonium compounds, le or imidazole compounds, isothiazolone compounds, pyrethroid compounds and other biocides such as imidacloprid; ?pronil; cy?uthrin; bifenthrin; permethrin; cypermethrin; and chlorpyrifos, iodopropynyl arbamate (IPBC); chlorothalonil; 2-(thiocyanatomethylthio) benzothiazole; alkoxylated diamines and carbendazim. When the organic biocide is used in the composition, the weight ratio of the organic biocide in the composition is generally in the range of from 0.001% to 10% by weight, with a preferred range 5% to 5% by weight and a more preferred range of 0.01% to Each of the organic biocides listed in Tables 1-4‘ of US. Publication No. 20050118280 are hereby cally incorporated by reference, in their entirety.

Non-limiting examples of quaternary ammonium compounds are: didecyldimethylammonium chloride; didecyldimethylammonium carbonate/bicarbonate; alkyldirnethylbenzylammonium chloride; alkyldimethylbenzylammonium carbonate/bicarbonate; cyldimethylammonium de; didodecyldimethylammoniurn carbonate/bicarbonate; didodecyldimethylammonium propionate; N,N-didecyl-N-methyl-poly(oxyethyl)ammonium propionate.

Non-limiting examples of triazole or imidazole compounds are: 14[242,4— dichloropheny1)-l ,3-dioxolanyl]methy1]-1H—1,2,4-triazole (azaconazole), l -R2RS,4RS:2RS,4SR)bromo-Z-(2,4-dichlorophenyptetrahydrofurfury1]-1 H-1,2,4~triazole (bromuconazole), (ZRS,3RS;2RS,3SR)(4-chlorophenyl)cyclopropy1—l-(1H-l,2,4—triazol anol (Cyproconazole), (2RS,3RS)-l-(2,4-dichloropheny1)—4,4-dimethyl(1H-1,2,4- l—l-yl)pentan—3~ol (diclobutrazol), cis—trans—3-chloromethy1-2—(1H-1,2,4—triazol-1~ ylmethyl)—1,3-dioxolan-2—yliphenyl rophenyl ether (difenoconazole), (E)-(R5)(2,4- dichloropheny1)-4,4-dimethyl—2—(lH—l ,2,4-triazol~l-y1)pentenol (diniconazole), ) (2,4-dichloropheny1)—4,4—dimethy1(lH—1,2,4—triazoly1)pentenol (diniconazole-M), (ZRS,3SR)—l43-(2-chloropheny1)-2,3~epoxy(4-fluorophenyl)propyl]-lH- 1,2,4-triazole (epoxiconazole), (RS)~ l 42—(2,4—dichloropheny1)—4—ethyl- 1 ,3 -dioxolan-2—ylmethyli- lH-l ,2,4- triazole (etaconazole), (RS)-4—(4-chloropheny1)phenyl—2-(1 H- 1,2,4-triazol-l- ylmethyl)butyronitrile (fenbuconazole), 3-(2,4~dichloropheny1)—6-fluoro(1H-1,2,4-triazol—1- y1)quinazolin-4(3 1 1)-one (fluquinconazole), bis(4~fluorophenyl)(methyl)(1l-I-l ,2,4~triazol ylmethyl)silane (?usilazole), (RS)-2,4'-difluoro-a—(lH-l ,2,4—triazol~1-ylmethyl)benzhydryl alcohol (?utriafol ), (2R8 ,5 RS;2RS ,5 SR)(2,4-dichlorophenyl)tetrahydr 0-5 -( l H- 1,2,4—triazol—l— ylmethy1)furyl 2,2,2-tri?uoroethyl ether (furconazole ), (2R8 ,5RS)(2,4- dichlorophenyptetrahydro-54 1 H— 1 ,2,4—triazol— 1 —yImethyl)furyl 2,2,2-tri?uoroethyl ether(?1rconazoIe-cis ), (RS)-2—(2,4-dichloropheny1)(1 H- 1,2,4—triazol—I-y1)hexan—2-01 (hexaconazole), 4-ch10robenzy1 —(2,4-dichloropheny1)~2-(1 H— 1,2,4-triazol y1)thioacetamidate (imibenconazoha), (1 RS,ZSR,5 RS; 1 RS ,ZSR,5 SR)—2—(4—chlor 1)—5 — isopr opyl— 1-(1 H- 1,2,4-triazol—1~y1methyl)cyclopentanol (ipconazole), (1 RS ,SRS; 1 RS ,5 (4— chlorobenzy1)-2 ,2-dimethyl(1H-1,2,4-triazol- 1 —ylmethyl)cyclopentanol (metconazole), (RS)- 2-(4-chloropheny1)-24 1 H— 1 ,2,4-triazolylmethyl)hexanenitri1e (myclobutanil ), (RS)—1 —(2,4- dichloro~(3-propy1phenethyl)-1 H- 1,2,4—triazole(penconazole), c ns- 1~[2-(2,4- dichloropheny1)—4-propyl- 1 ,3 —dioxolanylmethy1]- lH-l ,2,4—triazole (propiconazole), (RS)-2— [2—( 1 ~chlorocyclopropyl)—3 —(2—chloropheny1)-2—hydroxypropy11-2,4~dihydro— 1 ,2,4-ttiazole—3 - thione ioconazole), 3-(2,4-dich10ropheny1)~2—(lH—l,2,4—triazol—1-y 1)—quinazolin—4(3 1 1)-one (quinconazole), (RS)—2-(4-fluoropheny1)- l —(1H-1,2,4-triazoly1)-3 -(trimethy1si1y1)propan—2—o1 (simeconazole), (RS)-l-p-chloropheny1-4,4—dimethy1-3—(1H-1,2,4—triazol-1~y1methyl)pentan—3-ol onazole), propiconazole, (RS)-2—(2,4-dichlorophenyl)-3 —(1H—1 ,2,4~triazol— 1 -yl)propy1 1,1,2,2-tetra?uoroethy1 ether (tetraconazole), (RS)-l lorophenoxy)-3,3-dimethy1-1—(1 H—l ,2,4-triazol—1-y1)butan-2—one (triadimefon), (1 RS ,2RS; 1 RS ,ZSR)- 1-(4-chlorophenoxy)-3,3- dimethyl-l-(l H- 1,2,4-triazolyl)butanol (triadimenol), (RS)-(E)-5 —(4-chlorobenzylidene)- 2 ,2—dimethy1- l -(1H—1 ,2 ,4-triazol~ 1 -y1methy1)cyclopentanol (triticonazole), (E)-(RS)- 1 ~(4-ch1 oropheny1)-4,4 —d imethyl ~2-( 1 H— 1 ,2 ,4 ~triaz01- 1 ~y1)penten—3 ~ol (uniconazole), (E)-(S)(4- ch! orophenyI)—4,4 ~d l-24 1 H— 1 ,2 ,4 —triazolyl)penten—3 ~01 (uniconazole-P), and 2 -(2,4 - di?uoropheny1)-1—(1H-1,2,4—triazole-1—y1)—3-trimethylsily1propanol. Other azole compounds include: amisulbrom, bitertanol, ?uotrimazole, triazbutil, climbazole, clotrimazole, imazalil, oxpoconazole, prochloraz, tri?umizole, azaconazole, simeconazole, and hexaconazole.

Non~limiting examples of isothiazolone compounds are: methylisothiazolinone; r02-methy1~4~isothiazoline~3~one, 2-methy1-4—isothiazoline—3 -one, 2—n—octyl—4—isothiazoline—3 -one, 4,5-dichloro—2-n—octy1—4-isothiazoline—3-one, 2-ethy1isothiazoline-3—one, 4,5—dichloro cyclohexyl—4—isothiazolineone, -chloroethyl~4~isothiazoline~3—one, 2-octy1 azolone, -chloro—2-t-octy1isothiazoline—3-one, 1,2-benzisothiazoline-3—one, preferably -chloro-2~methyl-4—isothiazoline-3~one, 2-methyl~4—isothiazoline-3—one, Z-n—octy1—4— azoline-B-one, 4,5-dichloro-Z-n—octylisothiazolineone, nzisothiazoline—3-one, etc., more preferably 5-chloromethyIisothiazolineone, 2~n¢octyl—4-isothiazolineone, 4,5-dichlorc-2—n-octy othiazolineone, l,2~benzisothiazoline-3~one, chloromethylisothiazolinone; 4,5-Dichloron-octyl-3(2H)—isothiazolone; l,2-benzisothiazolin3-one.

Nonulimiting es of pyrethroid compounds include acrinathrin, allethrin, bioallethrin, barthrin, bifenthrin, bioethanomethrin, cyclethrin, rothrin, cy?uthrin, betacyfluthrin, cyhalothrin, gamma—cyhalothrin, lambda—cyhalothrin, cypermethrin, alphacyperrnethrin, beta—cypermethrin, theta—cypermethrin, zeta-cypermethrin, cyphenothrin, deltamethrin, dime?uthrin, dimethrin, empenthrin, fen?uthrin, fenpirithrin, pathrin, fenvalerate, alerate, ?ucythrinate, fluvalinate, tau-?uvalinate, furethrin, imiprothrin, metofluthrin, permethrin, biopermethrin, transpermethrin, phenothrin, prallethrin, pro?uthrin, pyresmethrin, resmethrin, bioresmethrin, cismethrin, te?uthrin, terallethrin, tetramethrin, tralomethrin, transfluthrin, etofenprox, flufenprox, halfenprox, fenbute, sila?uofen.

Preferred c biocides are tebuconazole and hrin.

The present invention also optionally comprises an aqueous type thickening agent.

Aqueous organic polymer, aqueous emulsion, clay minerals, phosphate and the like are the aqueous type of thickening agents. Typical examples of aqueous organic polymers are cellulose derivatives including cellulose esters and ethers. Examples of cellulose esters are cellulose nitrate, sulfate, cellulose phosphate, cellulose nitrite, cellulose xanthate, cellulose acetate, cellulose formate, and cellulose esters with other organic acids. es of ose ethers are methylcellulose, ethylcellulose, propylcellulose, benzylcellulose, carboxymethylcellulose, hydroxyethylcellulose, ypropylcellulose, hydroxybutylcellulose, cyanoethylcellulose, and carboxyethylcellulose. The preferred cellulose derivatives are cellulose ethers such as hydroxyethylcellulose, hydroxypropylcellulose, carboxymethylcellulose and carboxyethylcellulose. The weight percentage of the cellulose tive in the paste formulation is generally in the range of from about 0.01% to 50% with a preferred weight percentage of 0.1 to % and a more preferred weight percentage of 0.5 to 10%. rmore, the present invention also ally ses about 0.5% to about % of an inorganic clay thickening agent, or a mixture of such thickening agents. The inorganic clay thickening agents include a ?brous structure type such as attapulgite clay and ite clay, a non-crystal structure type such as one, and mixed layer structure type such as montmorillonite and kaolinte and the above layer structure types. Examples of inorganic clay minerals, but not limited to, are: attapulgite, dickite, saponite, rillonite, e, kaolinite, anorthite, halloysite, metahalloysite, chrysotile, lizardite, serpentine, antigorite, beidellite,stevensite, hectonite, smecnite, nacrite and sepiolite, montmorillonite, sauconite, stevensite, nontronite, saponite, hectorite, vermiculite, smecnite, sepiolite, nacrite, illite, sericite, glauconite-montmorillonite, roselite-montmorillonite, Bentone 38 (hectorite) and Bentone 34 (bentonite), chlorite—vermiculite, illite-montmorillonite, halloysite-montmorillonite, kaolinitemontmorillonite. The clay minerals employed in the compositions of the present invention also contain geable cations including, but not d to, aluminum ions, protons, sodium ions, potassium ions, calcium ions, magnesium ions, m ions, and the like.

Among the above inorganic clay ls, lgite, hectorite, bentonite, montmorillonite, sauconite, smecnite, stevensite, beidellite, nontronite, saponite, hectorite, vermiculite, nacrite, and sepiolite are particularly preferable for the present ion.

Further, these inorganic clay minerals show a good thickening effect and thixotOpic little sagging property in comparison with other aqueous thickening agents. Therefore, they show a and also they are very easy to be rinsed out by water in comparison with organic thickening agents.

It should be appreciated that thickening agents other than described herein can be used.

Optionally, the present invention also includes chemical additives that retard the drying of the paste composition. These are usually a blend of several glycols, such as ethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol and their derivatives. By evaporating far more slowly than water, glycols or their derivatives can slow down the drying such as glycerin and glycerol that absorb or hold process of the paste composition. Humectants, water can also be added to retard or slow drying.

The preservative paste compositions of this invention can be applied by various processes of supplemental or remedial treatment or protection of in-service wooden structures.

The compositions of this invention are suitable for incorporation into wraps or ready-to-use es, injection into voids or cavities by pressure or by gravity and solid rods or cartridges.

The paste compositions of this invention can be easily incorporated into a suitable support material to form a ready-to-use bandage or wrap that can d to in~service utility poles and other wooden structures. Numerous t materials have been identi?ed in literature and may include r ?lms, fabrics, ?berglass, ter ?ber, polypropylene, porous r compositions and others that allow for the transfer or diffusion of vative chemical from the e to the wood substrate. The paste composition may be applied to the support al by toweling, rolling, brushing and the like. The paste composition can be directly applied to the support material or may require the use of a binder or resin such as for example acrylate resins or PVC with plasticizers. To e the adhesion between the paste compositions and support material the combination may be air-dried or dried in an oven at elevated temperatures.

The paste compositions of this invention may also be formed into solid rods by extrusion, rolling or pressing. Once suf?ciently dried, the rods can be cut to length and inserted into predrilled holes in in-service utility poles or other wooden structures. As with the bandages or wraps, resins or binders may be added to improve the dimensional stability of the rods.

The paste compositions of this invention may be injected into internal voids or es through predrilled holes into in-service poles, posts, piling, cross-ties and other wooden structures by pressure processes or by gravity feed.

The following examples are provided to further be certain embodiments of the invention, their preparation and ation as remedial or supplemental paste preserving system, but are in no way meant to limit the scope of the ion. For the experiments, penetration testing has been found to be an effective means of establishing the consistency and shear stability of compositions of this invention. Penetrometers are generally used for consistency tests on a wide range of food products, cosmetics, greases, pastes and other solid to semisolid products. Penetrometers utilize a standard cone or needle that is released from the Penetrometer and d to drop feely into the sample for 5 seconds at constant temperature. The depth of penetration of the cone into the sample is measured in tenths of a millimeter (tmm) by the Penetrometer. It has been establish through testing that the preferable penetration of the compositions of this invention range from about 125 to 425 tmm when using a standard ometer equipped with a 102.5 gram brass cone with a ess steel tip. A more preferable range of consistency for the present invention is about 175 to 375 tmm and a consistency or shear stability of about 200 to 300 tmm is particularly preferable for the present invention.

The preferred viscosities of the thixotropic itions of the present invention, during cture, is between 275 and 425 tenths of a millimeter (tmm) viscosity as measured using a penetrometer. More preferably the viscosities of the compositions of the present invention is between 300 and 400 tmm. Most ably the viscosities ofthe compositions ofthe present invention is between 320 and 340 tmm.

The preferred viscosities of the thixotropic compositions of the present invention is between 175 and 375 tenths of a millimeter (tmm) viscosity as measured using a penetrometer.

More preferably the viscosities of the compositions of the present invention is between 200 and 300 tmm. Most preferably the viscosities ofthe itions ofthe present invention is between 210 and 250 tmm.

For determination of acceptability of viscosity, spreadability and adherence, compositions of the present invention can be rolled, troweled or brushed on wooden objects or more preferably to in-service y poles, cross-ties or other wooden structures. Desirable compositions of the present invention should be self—supporting, have good spreadability such that the composition can be easily d with a roller, trowel or brush t g or slumping off the wooden substrate or application tool and will easily adhere to a wooden substrate.

The Examples listed below illustrate methods for preparing various compositions and treating wood according to the invention. These Examples below, illustrate methods for preparing alternative ns of the inventive compositions. The methods described in these Examples are illustrative only, and are not intended to limit the invention in any manner and should not be construed to limit the scope of claims herein.

EXAMPLE 1 A supplemental/remedial preservative paste composition was prepared by blending together in the order listed; 41.60 parts water, 6.00 parts of a fine copper dispersion comprised of 33.3% copper carbonate, 0.50 parts of a commercially available ose ether ner, 43 .70 parts sodium tetraborate decahydrate, and 8.20 parts attapulgite clay thickener. This remedial preservative paste contained 2.00 parts copper as derived from the ?ne copper carbonate sion for a weight ratio of 21 .90 parts boron compound to 1.00 part copper.

The supplemental/remedial preservative paste ition formulated according to the above example was applied to a wooden substrate using a trowel and was found to have desirable physical properties including viscosity, spreadability and adherence for application to in-service utility poles, cross-ties and other wooden structures. Consequently, a preservative paste composition was obtained.

EXAMPLE 2 A supplemental/remedial preservative paste composition was prepared by blending together in the order listed; 33.30 parts water, 3.00 parts of a ?ne copper dispersion comprised of 33.3% copper hydroxide, 10.00 parts glycerin, 2.00 parts of a commercially available cellulose ether thickener, 43.709 parts sodium tetraborate decahydrate, 1.00 part calcium sulfate ?ller and 7.00 parts attapulgite clay thickener. This remedial preservative paste contained 1.00 parts copper as derived from the ?ne copper hydroxide dispersion for a weight ratio of 43.70 parts boron nd to 1.00 part copper.

The supplemental/remedial preservative paste ition ated according to the above example was applied to a wooden substrate using a trowel and was found to have ble physical properties ing viscosity, spreadability and adherence for application to in-service utility poles, cross-ties and other wooden structures. Consequently, a preservative paste composition was obtained.

EXAMPLE 3 A supplemental/remedial preservative paste composition was prepared by ng together in the order listed; 30.24 parts water, 1.50 parts of a ?ne copper dispersion comprised of 33.3% basic copper carbonate, 10.00 parts glycerin, 3.00 parts of a commercially available cellulose ether thickener, 47.76 parts sodium tetraborate decahydrate, 1.50 part calcium e ?ller and 6.00 parts attapulgite clay thickener. This remedial preservative paste contained 0.50 parts copper as derived from the ?ne basic copper carbonate dispersion for a weight ratio of 95.52 parts boron nd to 1.00 part copper.

The supplemental/remedial vative paste composition formulated according to the above example was applied to a wooden substrate using a trowel and was found to have desirable physical properties including viscosity, spreadability and adherence for application to in—service utility poles, cross—ties and other wooden structures. Consequently, a preservative paste composition was obtained.

EXAMPLE 4 A mental/remedial preservative paste composition was prepared by blending er in the order listed; 44.60 parts water, 0.02 parts bifenthrin, 3.00 parts of a ?ne copper dispersion comprised of33.3% cupric oxide, 0.50 parts of a commercially available cellulose ether thickener, 43.70 parts sodium tetraborate decahydrate, and 8.2 parts attapulgite clay thickener.

This remedial preservative paste contained 1.00 parts copper as derived from the fine cupric oxide dispersion for a weight ratio of 43.7 parts boron compound to 1.00 part copper.

EXAMPLE 5 A supplemental/remedial preservative paste ition is prepared by blending together in the order listed; 34.00 parts water, 0.10 parts nazole, 2.25 parts of a ?ne copper dispersion comprised of 33.3% basic copper carbonate, 10.00 parts glycerin, 3.00 parts of a commercially available cellulose ether thickener, 21.85 parts sodium tetraborate decahydrate, 21.85 parts boric acid, 1.00 part calcium e ?ller and 6.0 parts attapulgite clay thickener.

This remedial preservative paste contains 0.75 parts copper as d from the ?ne basic copper carbonate dispersion for a weight ratio of 58.27 parts boron compound to 1.00 part copper.

EXAMPLE 6 A supplemental/remedial preservative paste composition was prepared by blending together in the order listed; 44.6 parts water, 0.50 parts of a commercially available cellulose ether ner, 3.00 parts of a ?ne copper hydroxide dispersion comprised of 33.3% copper carbonate, 0.10 parts bifenthrin, 0.10 parts tebuconazole, 43.70 parts sodium tetraborate decahydrate, 6.5 parts attapulgite clay thickener and 1.5 parts m sulfate ?ller. This remedial preservative paste ned 1.00 parts copper as derived from the fine copper carbonate dispersion for a weight ratio of 43.7 parts boron compound to 1.00 part copper.

Penetration testing performed on the paste composition formulated according to the example above showed a penetration of 216 tmm. In addition, the supplemental/remedial preservative paste composition formulated according to the above example was applied to a wooden substrate using a trowel and was found to have desirable physical properties including viscosity, spreadability and adherence for ation to in-service utility poles, cross-ties and other wooden structures. Consequently, a preservative paste composition was obtained.

EXAMPLE 7 A supplemental/remedial preservative paste ition was prepared by blending together in the order listed; 37.00 parts water, 6.51 parts of a fine copper dispersion sed of 31.6% cuprous oxide, 0.50 parts of a commercially ble cellulose ether thickener, 50.00 parts sodium tetraborate decahydrate, and 6.00 parts attapulgite clay thickener. This remedial preservative paste contained 2.06 parts copper as derived from the fine cuprous oxide dispersion for a weight ratio of 2427 parts boron compound to 1.00 part copper.

Penetration testing performed on the paste composition formulated according to the example above showed a penetration of 275 tmm. Further, the paste composition formulated according to the above example was brushed to 18 inches of the below ground section of an vice utility pole. This paste was found to have ble physical properties including Viscosity, ability and adherence for application to in-service utility poles, cross-ties and other wooden structures. Consequently, a preservative paste composition was obtained.

EXAMPLE 8 A mental/remedial vative paste composition was prepared by blending together in the order listed; 44.6 parts water, 3.00 parts of a ?ne copper dispersion comprised of 33.3% copper carbonate, 0.70 parts pigmented dyes, 0.50 parts of a commercially available cellulose ether thickener, 43.70 parts sodium orate decahydrate, and 7.50 parts attapulgite clay thickener. This remedial vative paste contained 1.0 parts copper as derived from the ?ne copper ate dispersion for a weight ratio of 43.7 parts boron compound to 1.00 part copper.

Penetration testing performed on the paste composition formulated ing to the example above showed a penetration of 211 tmm. Further, the paste composition ated according to the above example was brushed to 18 inches of the below ground n of an in—service utility pole by an experienced preservative chemical applicator. This paste was found to have ble physical properties including viscosity, spreadability and adherence for application to in-service utility poles, cross—ties and other wooden structures. Consequently, a preservative paste composition was obtained.

Further, the paste formed was applied to the surface of southern pine dimensional lumber that had previously been vacuum-pressure impregnated with water. The lumber was ted with water to simulate moisture regimes that are typically present within the ground-line region of in—service utility poles and other wooden structures and that is required to provide mobility of the preservative paste into the wood substrate, The paste was applied at a thickness of a sixteenth of an inch and sealed to the lumber with a water impermeable wrap such that is used in commercial practice. At periods of2, 4 and 6 weeks, small incremental wafers were taken from the treated sections of the lumber. Wafers were sprayed with the copper penetration reagent Chrome Azurol S in ance with American Wood Protection Association’s (AWPA) Standard A3~08 (which is incorporated herein by reference in its entirety), Method 2, Method for Determining ation of Copper-Containing Preservatives. It was ined by visual inspection that 1/4 inch from the surface of copper had penetrated, or diffused through the wood up to a application. It was further visually determined that boron had penetrated the wood up to 1-1/2 inches from the treated surface using AWPA Standard A3-08, Method 17, Standard Method for Determining Penetration of Boron-Containing Preservatives and Fire Retardants.

EXAMPLE 9 A supplemental/remedial vative paste composition was prepared by blending together in the order listed; 45.05 parts water, 3.00 parts of a ?ne copper dispersion comprised of 33.3% copper carbonate, 0.75 parts of a commercially available cellulose ether thickener, 43 .70 parts sodium tetraborate decahydrate, and 7.50 parts attapulgite clay thickener. This remedial preservative paste ned 1.00 parts copper as derived from the fine copper carbonate dispersion for a weight ratio of 43.7 parts boron compound to 1.00 part copper.

Penetration testing performed on the paste composition formulated according to the example above showed a penetration of 220 tmm.

Further, the paste composition formulated according to the above example was brushed to 18 inches of the belowground section of 10 utility-pole sections led in a ?eldtest plot d in Gainesville, FL. The paste product was installed by an experienced preservative chemical applicator and was found to have desirable physical properties including viscosity, spreadability and adherence for application to in—service utility poles, cross-ties and other wooden structures. al penetration and ion was assessed at 12 months following treatment with the paste composition formulated according to the above example. Copper was detected at fungitoxic levels in the outer 'A inch of the test poles at 12 months following treatment. Boron was detected at levels above the fungitoxic threshold level up to a depth of 3.0 inches from the pole surface after 12 months. Thus desirable chemical penetration and retention levels were obtained.

EXAMPLE 10 A supplemental/remedial vative paste composition is ed by blending together in the order listed; 33.66 parts water, 0.04 parts bifenthrin, 0.10 parts tebuconazole, 6.00 parts of a ?ne copper dispersion comprised of33.3% basic copper carbonate, 10.00 parts in, 0.50 parts of a commercially available cellulose ether thickener, 21.85 parts sodium orate decahydrate, 21.85 parts sodium ?uoride, and 6.0 parts attapulgite clay thickener.

This remedial preservative paste contains 2.00 parts copper as derived from the ?ne basic copper carbonate dispersion for a weight ratio of 10.92 parts boron compound to 100 part copper and 10.92 parts ?uoride compound to 1.00 part copper.

EXAMPLE 11 A supplemental/remedial preservative paste composition was prepared by blending together in the order listed; 44.6 parts water, 3.00 parts of a ?ne copper dispersion comprised of 33.3% copper hydroxide, 0.70 parts pigmented dyes, 0.50 parts of a commercially available cellulose ether ner, 43.70 parts boric acid, and 7.50 parts attapulgite clay thickener. This remedial preservative paste contained 1.0 parts copper as derived from the ?ne copper hydroxide dispersion for a weight ratio of 43.7 parts boron compound to 1.00 part copper.

EXAMPLE 12 A supplemental/remedial preservative paste composition was prepared by blending together in the order listed; 44.6 parts water, 3.00 parts of a fine copper dispersion comprised of 33.3% copper hydroxide, 0.70 parts pigmented dyes, 0.50 parts of a commercially available cellulose ether thickener, 43.70 parts sodium e, and 7.50 parts attapulgite clay thickener.

This remedial vative paste contained 1.0 parts copper as derived from the ?ne copper hydroxide dispersion for a weight ratio of 43.7 parts ?uoride compound to 1.00 part copper.

EXAMPLE 13 A supplemental/remedial vative paste composition is prepared by blending together in the order listed; 41.79 parts water, 9.38 parts propylene glycol, 1.5 parts of a ?ne basic copper carbonate dispersion sed of 33.3% copper, 0.33 parts didecyldimethylammonium carbonate/bicarbonate, 2.00 parts of a commercially available cellulose ether thickener, 36.0 parts disodium octaborate tetrahydrate, 2.0 part calcium sulfate ?ller and 7.0 parts lgite clay thickener.

This remedial preservative paste contains 0.50 parts copper as derived from the ?ne basic copper ate dispersion for a weight ratio of 72.00 parts boron nd to 1.00 part copper.

EXAMPLE 14 A supplemental/remedial preservative paste composition was prepared by blending together in the order listed; 44.6 parts water, 3.00 parts of a ?ne copper dispersion comprised of 33.3% copper carbonate, 0.70 parts pigmented dyes, 0.50 parts of a commercially available cellulose ether thickener, 43.70 parts sodium tetraborate decahydrate, and 7.50 parts attapulgite clay thickener. This remedial preservative paste contained 1.0 parts copper as derived from the ?ne copper carbonate dispersion for a weight ratio of 43.7 parts boron compound to 1.00 part copper.

A series of preservative treating formulations were prepared by ng the paste composition formulated according to the example above with water. The stable dispersions were used to treat southern pine test stakes measuring 0.75 X 0.75 X 0.75 inches by the full-cell process.

Stable sions were ed to vacuum-pressure treat the test blocks rather than apply the preservative paste to the surface of the pine test blocks, which may have acted as a barrier or strong repellent. The treated cubes were d to two common test fungi to te the bio-ef?cacy of the preservative formulations following procedure bed in AWPA Standard BIO—12, Standard Method of Testing Wood Preservatives by Laboratory Soil-B lock Cultures. Upon completion ofthe soil-block test, the cubes were found to have less than 2% weight loss, ting essentially no fungal attack to the treated cubes. In comparison, untreated wood cubes had approximately 60% weight loss after being exposed to the test fungi.

EXAMPLE 15 A series of preservative treating formulations were prepared by diluting the paste composition formulated according to Example 14 above with water. The stable dispersions were used to treat southern pine test stakes measuring 0.75 X 0.75 X 0.75 inches by the full-cell process.

Stable dispersions were ed to vacuum-pressure treat the test blocks rather than apply the preservative paste to the surface ofthe pine test blocks, which may have acted as a barrier or strong ent. The treated cubes were exposed to termites to evaluate the resistance of the preservative formulations following the procedure described in AWPA rd E1-12, Standard Method for Laboratory Evaluation to Determine Resistance to Subterranean Termites. Upon completion of the e test, the cubes were found to have less than 5% weight loss with visual ratings of 8.2 to 9.4 (scale of 0 to 10, 0 being complete failure and 10 having no attack), indicating excellent protection against termite attack. In ison, untreated wood cubes had approximately 35% weight loss and a visual rating of 3.8 after being exposed to the test termites.

EXAMPLE 16 A supplemental/remedial preservative paste composition was prepared in accordance with Example 14. The paste composition was tested for volatile organic nds (VDC) t in accordance with EPA Method 8620, Volatile Organic Compounds by Gas Chromatography Mass Spectrometry (GC/MS).

Two commercially available remedial preservative paste formulations were also tested for VOC content in accordance with EPA Method 24, SCAQMD 304 or Modi?ed EPA Method 8620 (which are incorporated by reference in their entireties). The ?rst commercially available paste formulation, known to n an oil-borne copper naphthenate complex was ed to have a VOC content of 340 grams VOC /liter coating. The second commercial paste product was formulated according to US. Pat. No. 8,221,797, which contained a micronized form of oxine copper that had a VOC content of 36 gramsVOC/liter coating. Testing of a remedial preservative paste composition made in accordance with the present invention was ed to have a non-detectable level ofVOCs (0.1% LCD). An oil-home copper naphthenate solution containing 2% copper was analyzed to have a VOC t of 698 grams ter coating. Consequently, a al vative paste formulation that is essentially free of volatile organic compounds was achieved.

EXAMPLE 17 The supplemental/remedial preservative paste ition of Example 14 was continuously extruded through a 1/2 inch diameter aperture and subsequently cut into 3 inch lengths. The rods were then dried at 90°F for 24 hours. The resulting preservative rods were found to be structurally sound, uniformly shaped and preferable for insertion into lled holes such that are drilled into in-service utility poles, piling, cross-ties and other wooden structures for the afterprotection against wood destroying decay fungi. Further, the rods were placed on a wet sponge partially submerged in a water bath to allow continual wicking of water from the bath to the rod. After six weeks it was determined through analysis that the water bath contained appreciable levels of copper and boron. uently, a preservative rod composition was achieved.

EXAMPLE 18 The supplemental/remedial preservative paste composition of Example 9 was injected into 3/8 inch holes drilled into an vice utility pole ning a large decay void. The preservative paste formulation was found to be easily pumped or transferred with standard pneumatic pumping equipment or by gravity feed. The pole section containing the void was subsequently ted and the paste composition was found to have completely ?lled the void and achieved intimate contact with the surfaces of the wood such that would provide adequate diffusion of biocide to the wood substrate in the presence of moisture or liquid water.

Consequently, a preservative internal treatment composition was achieved.

The supplemental/remedial preservative paste composition of e 10 was rolled onto a polyethylene sheet to a uniform thickness of 0.0625 inches. The subsequent paste/support system was cut to 21 inches in length and d to the below ground portion of an in—service utility pole such that the entire circumference ofthe pole was incased to 18 inches below ground. As the paste/support system was handled and orted the paste did not slump, run or drip offofthe ting material. Removal ofthe pastelsupport system from the pole shortly after application found that the paste composition adhered and maintained intimate contact with to the pole surface such that would provide te diffusion of the biocide to the wood substrate in the presence of moisture or liquid water. Consequently, a preservative wrap or bandage composition was achieved.

EXAMPLE 20 The preservative penetration and retention characteristics in ?lll—size southern pine pole sections initially treated with pentachlorophenol ered from ?eld testing the supplemental/remedial preservative paste composition formulated according to Example 9 above was compared to known commercially available paste formulations and associated third party generated penetration and retention data. al penetration and ion was assessed at 12 months following treatment with the paste composition formulated according to Example 9 above. Chemical penetration and retention may be measured 'by any method known in the art. Copper was detected at the fungitoxic level of 0.04 pounds per square foot (PCF) in the outer 1/: inch of the test poles at 12 months following treatment. The Oregon State University — Utility Pole Research Cooperative (OSU-UPRC) has ished a threshold level for copper of 0.04 PCP when used in remedial preservative applications (OSU—UPRC 2013 Annual Report). This value also corresponds with the copper threshold retention level listed for copper naphthenate in AWPA Use Category 3B (AWPA 2013 Book of Standards).

The UPRC established a ?eld trial in November 2004 to evaluate the performance of external supplemental preservative pastes on southern pine y poles initially treated with pentachlorophenol. This study included 3 commercially available copper containing paste formulations each ofwhich contained copper at 2% wt/wt that had been complexed, or solubilized with the use of organic solvents. Copper levels for Formulation A, a ?iel oil based preservative found to be paste that utilized an oil based naphthenic acid to complex the copper source, were 70% in excess of the established copper threshold level of 0.04 PCF in the outer 1/: inch of the test poles. Copper levels for Formulation B, a water based preservative paste that ed monoethanolamine to complex the copper source, were found to be 168% in excess of the established copper threshold level in the outer ‘A inch of the test poles. Copper levels for Formulation C, a water based preservative paste that ed a water dispersible enic acid to complex the copper source, were found to be 167% in excess of the established copper old level 0.04 PCF in the outer 'A inch ofthe test poles. The data for Formulation C represents 2 year data as the 1 year data was unavailable.

The uncontrolled mobility of the copper component from current paste compositions as demonstrated from the UPRC study is a concern from a performance standpoint.

Water- and oil-soluble copper complexes provide an uncontrolled dose to the wooden structure to be ved that quickly disperses beyond the intended zone of protection within the wooden ure and rapidly depletes the copper reservoir contained within the residual paste composition diminishing the ability of the treatment to provide prolonged periods ofprotection from the action ofdecay and wood ying insects such as termites. The amount of copper that is delivered by prior art formulations into the outer shell of the test poles is excessive and unnecessary as levels are far in excess of fungitoxic thresholds and a large degree of protection is also afforded by co-biocides in each of the formulations and by any residual chemical remaining in the poles from the initial preservative treatment.

The slow or controlled release of the ized copper carbonate from the supplemental/remedial preservative paste composition made in accordance with this ion was an unexpected and surprising occurrence.

Claims

Claims (31)

What is claimed is:

1. An aqueous wood preservative paste composition comprising: a dispersion of solid particles of a substantially insoluble copper compound in an amount of about 0.001% to about 10% by weight of the composition; a boron-containing compound; an aqueous carrier; and a thickening agent, wherein the paste composition has a ity of between 125 and 425 tenths of a millimeter (tmm) as measured using a penetrometer ed with a 102.5 gram brass cone with a stainless tip d freely into the sample for 5 seconds at a constant temperature, and wherein at least 20% of particles of the paste ition comprise les with diameters greater than 25 microns.

2. The wood preservative composition of claim 1, wherein at least 30% of the particles of the paste composition comprise particles with diameters r than 25 microns.

3. The wood preservative composition of claim 2, wherein less than 20% of the particles of the paste composition comprise particles with diameters greater than 100 microns.

4. The wood preservative ition of claim 1, wherein the composition contains between 1 and 5% copper atoms by weight of the composition.

5. The wood preservative composition of claim 1, wherein the composition contains between about 0.1 to 1% copper atoms by weight of the composition.

6. The wood preservative composition of claim 1, wherein the copper compound is selected from the group consisting of copper hydroxide, cupric oxide, cuprous oxide, copper carbonate, basic copper carbonate, copper oxychloride, copper dimethyldithiocarbamate, copper e or copper borate.

7. The wood preservative composition of claim 1, wherein the paste is thixotropic.

8. The wood preservative composition of claim 1, wherein the copper compound is substantially insoluble in the carrier.

9. The wood preservative composition of claim 1, wherein the boron-containing compound is a boric acid, a metal borate, a sodium borate, or a ium borate.

10. The wood vative composition of claim 1, further comprising one or more c biocides.

11. The wood vative composition of claim 1, wherein the thickening agent is an organic thickener.

12. The wood preservative composition of claim 11, wherein the organic thickener is cellulosederived.

13. The wood preservative ition of claim 1, wherein the thickening agent is present in an amount of about 0.01% to about 50% by weight of the composition.

14. The wood preservative composition of claim 1, wherein the thickening agent is present in an amount of about 0.5% to about 10% by weight of the composition.

15. The wood preservative composition of claim 1, wherein the thickening agent is an inorganic thickener.

16. The wood preservative composition of claim 15, wherein the inorganic thickener is a clay.

17. The wood preservative composition of claim 15, wherein the inorganic thickener is t in an amount of about 0.5% to about 30% by weight of the composition.

18. The wood preservative composition of claim 1, r comprising a drying retardant or a humectant, or both.

19. The wood preservative composition of claim 1, n the thickening agent is a mixture of organic and inorganic thickeners.

20. A method for remedial treatment of wood, comprising the step of applying the composition of claim 1 to a wooden structure.

21. The method of claim 20, wherein the composition is d onto or into the wooden structure.

22. The method of claim 20, wherein the in-service wood product is a y pole, a railroad tie or a wooden bridge.

23. A method for preparing the wood preservative composition of claim 1, sing the step of maintaining the viscosity of the wood preservative composition at between 275 and 425 tmm using a penetrometer equipped with a 102.5 gram brass cone with a ess tip dropped freely into the sample for 5 seconds at a constant temperature.

24. The method of claim 23, comprising the step of milling a copper compound to particles with a er between 0.01 and 1 micron.

25. A method for preparing the wood preservative composition of claim 1, comprising the step of blending solid particles of a substantially insoluble copper compound comprising a particle size diameter between 0.01 and 25 s; a boron-containing compound; an aqueous carrier; and a thickening agent, to produce a paste composition with a viscosity of between 125 and 425 tenths of a millimeter (tmm) as measured using a penetrometer equipped with a 102.5 gram brass cone with a stainless tip dropped freely into the sample for 5 seconds at a constant temperature.

26. The method of claim 25, wherein the solid particles of a substantially insoluble copper compound comprise a particle size diameter between 0.1 and 10 microns.

27. A method of delivering a fungitoxic amount of copper ion to an interior portion of a wooden product comprising the steps of: applying an aqueous wood preservative paste composition comprising a sion of solid particles of a substantially insoluble copper compound in an amount of about 0.001% to about 10% by weight of the ition; a boron-containing nd; an aqueous carrier; and a thickening agent, wherein the paste composition has a viscosity of between 125 and 425 tenths of a eter (tmm) as ed using a penetrometer equipped with a 102.5 gram brass cone with a stainless tip dropped freely into the sample for 5 seconds at a constant temperature, wherein at least 20% of particles of the paste composition se particles with diameters greater than 25 microns; and wherein applying said aqueous wood preservative composition to said wooden structure produces penetration of copper ions into an interior portion of the wooden structure to a fungicidally effective level.

28. The method of claim 27, wherein the oxic amount is about 0.04 pounds per square foot (PCF).

29. The method of claim 28, wherein the fungitoxic amount is not more than 50% greater than 0.04 PCF.

30. The method of claim 28, wherein the fungitoxic amount is not more than 30% greater than 0.04 PCF.

31. The method of claim 27, wherein the copper ions are cuprous or cupric.