Particulate wood preservative and method for producing same

Abstract

A wood preservative includes injectable particles comprising one or more sparingly soluble copper salts. The copper-based particles are sufficiently insoluble so as to not be easily removed by leaching but are sufficiently soluble to exhibit toxicity to primary organisms primarily responsible for the decay of the wood. Exemplary particles contain for example copper hydroxide, basic copper carbonate, copper carbonate, basic copper sulfates including particularly tribasic copper sulfate, basic copper nitrates, copper oxychlorides, copper borates, basic copper borates, and mixtures thereof. The particles typically have a size distribution in which at least 50% of particles have a diameter smaller than 0.25 μm, 0.2 μm, or 0.15 μm. At least about 20% and even more than 75% of the weight of the particles may be composed of the substantially crystalline copper salt. Wood or a wood product may be impregnated with copper-based particles of the invention.

1 . A method of preserving wood comprising the steps of 
 A) providing an aqueous wood preservative slurry comprising: 
 a plurality of injectable first particulates comprising at least 20% by weight of a sparingly soluble copper salt, wherein the d 96  of these first particulates is about 1 micron or less, meaning 96 percent of the total volume of the first particulates have a diameter of about 1 micron or less, the d 99  is about 1.5 microns or less, meaning 99% of the total volume of the first particulates have a diameter equal to or less than about 1.5 microns; and the d 50  is greater than 0.02 microns, meaning 50% of the total volume of the first particulates have a diameter greater than 0.02 microns; and  
   B) injecting the aqueous wood preservative slurry into wood.    
     
     
         2 . The method of  claim 1 , wherein the d 50  is between about 0.05 microns and about 0.5 microns, meaning 50% of the total volume of the first particulates have a diameter equal to or less than a value between about 0.05 microns and about 0.5 microns.  
     
     
         3 . The method of  claim 1 , wherein the d 50  is between about 0.1 microns and about 0.3 microns, meaning 50% of the total volume of the first particulates have a diameter equal to or less than a value between about 0.1 microns and about 0.3 microns.  
     
     
         4 . The method of  claim 2 , wherein the sparingly soluble copper salt comprises copper borate.  
     
     
         5 . The method of  claim 1 , wherein the sparingly soluble copper salt comprises copper borate and at least one of basic copper carbonate or copper hydroxide, wherein different particulates can one or more of the three listed copper salts.  
     
     
         6 . The method of  claim 2 , wherein the sparingly soluble copper salt comprises basic copper carbonate.  
     
     
         7 . The method of  claim 2 , wherein the sparingly soluble copper salt comprises copper hydroxide.  
     
     
         8 . The method of  claim 7 , wherein the copper hydroxide comprises between 6 parts and 20 parts magnesium per 100 parts copper.  
     
     
         9 . The method of  claim 7 , wherein the copper hydroxide comprises between 6 parts and 20 parts zinc per 100 parts copper.  
     
     
         10 . The method of  claim 1 , wherein the sparingly soluble copper salt comprises tribasic copper sulfate, copper oxychloride, basic copper nitrate, basic copper phosphate, basic copper phosphosulfate, or combinations thereof.  
     
     
         11 . The method of  claim 1 , wherein the sparingly soluble copper salt comprises copper ferricyanide, copper ferricyanate, copper carbonate, copper borate, copper silicate, copper fluorosilicate, copper thiocyanate, copper boride, or mixture thereof.  
     
     
         12 . The method of  claim 2 , wherein at least a portion of the first particulates comprise Cu 2 O.  
     
     
         13 . The method of  claim 1 , wherein d 96  of these first particulates is about 0.5 micron or less, meaning 96 percent of the total volume of the first particulates have a diameter of about 0.5 micron or less, the d 99  is about 1 microns or less, meaning 99% of the total volume of the first particulates have a diameter equal to or less than about 1 micron; and the d 50  is between 0.05 microns and 0.4 microns, meaning 50% of the total volume of the first particulates have a diameter equal to or less than a value between 0.05 microns and about 0.4 microns.  
     
     
         14 . The method of  claim 1 , wherein the injectable first particulates had been wet-milled in the presence of a liquid comprising a surface active agent and an effective amount of milling beads having a diameter between 0.1 mm and 0.8 mm and a density greater than about 3 grams/cm 3 .  
     
     
         15 . The method of  claim 1 , wherein the aqueous wood preservative slurry further comprises a substantially insoluble organic biocide, wherein at least a portion of the substantially insoluble organic biocide is coated on the first particulates.  
     
     
         16 . The method of  claim 1 , wherein the aqueous wood preservative slurry further comprises a substantially insoluble organic biocide selected from biocidal quaternary ammonium compounds; biocidal azoles; biocidal triazoles, and moldicides, wherein at least 20% by weight of the substantially insoluble organic biocide is coated on the first particulates.  
     
     
         17 . The method of  claim 1 , wherein the aqueous wood preservative slurry further comprises a plurality of injectable second particulates comprising at least 20% by weight of an injectable solid substantially insoluble organic biocide, wherein the d 96  of these second particulates is about 1 micron or less, meaning 96 percent of the total volume of the second particulates have a diameter of about 1 micron or less, and the d 90  is about 1.5 microns or less, meaning 99% of the total volume of the second particulates have a diameter equal to or less than about 1.5 microns.  
     
     
         18 . The method of  claim 17 , wherein the d 96  of these second particulates is about 0.5 micron or less, meaning 96 percent of the total volume of the second particulates have a diameter of about 0.5 micron or less, and the the d 50  is between about 0.05 microns and about 0.4 microns, meaning 50% of the total volume of the second particulates have a diameter equal to or less than a value between about 0.05 microns and about 0.4 microns.  
     
     
         19 . The method of  claim 17 , wherein the injectable second particulates had been wet-milled in the presence of a liquid comprising a surface active agent and an effective amount of milling beads having a diameter between 0.1 mm and 0.8 mm and a density greater than about 5.5 grams/cm 3 .  
     
     
         20 . The method of  claim 1 , wherein the aqueous wood preservative slurry further comprises third particulates comprising at least 20% by weight of a sparingly soluble zinc salt, zinc oxide, iron oxide, or any mixture thereof, wherein the d 96  of the third particulates is about 1 micron or less, meaning 96 percent of the total volume of the third particulates have a diameter of about 1 micron or less, and the d 99  is about 1.5 microns or less, meaning 99% of the total volume of the third particulates have a diameter equal to or less than about 1.5 microns.  
     
     
         21 . A method of preserving wood comprising the steps of 
 A) providing an aqueous wood preservative slurry comprising: 
 a plurality of injectable first particulates comprising at least 20% by weight of a sparingly soluble copper salt, of a sparingly soluble zinc salt, of a substantially insoluble organic biocide, or any combination thereof, wherein the d 96  of the first particulates is about 1 micron or less, meaning 96 percent of the total volume of the first particulates have a diameter of about 1 micron or less, the d 99  is about 1.5 microns or less, meaning 99% of the total volume of the first particulates have a diameter equal to or less than about 1.5 microns; and the d 50  is greater than 0.02 microns, meaning 50% of the total volume of the first particulates have a diameter greater than 0.02 microns; and  
   B) injecting the aqueous wood preservative slurry into wood.    
     
     
         22 . The method of  claim 21 , wherein the d 50  is between about 0.05 microns and about 0.5 microns, meaning 50% of the total volume of the first particulates have a diameter equal to or less than a value between about 0.05 microns and about 0.5 microns.  
     
     
         23 . The method of  claim 21 , wherein the d 50  is between about 0.1 microns and about 0.3 microns, meaning 50% of the total volume of the first particulates have a diameter equal to or less than a value between about 0.1 microns and about 0.3 microns.  
     
     
         24 . The method of  claim 21 , wherein the first particulates comprise one or more of basic copper carbonate, copper hydroxide, copper hydroxide comprising between 6 parts and 20 parts magnesium per 100 parts copper; copper hydroxide comprising between 6 parts and 20 parts magnesium per 100 parts copper, copper hydroxide comprising 0.1 to 5% copper phosphate, tribasic copper sulfate, copper oxychloride, basic copper nitrate, basic copper phosphate, basic copper phosphosulfate, or combinations thereof.  
     
     
         25 . The method of  claim 24 , wherein d 96  of these first particulates is about 0.5 micron or less, meaning 96 percent of the total volume of the first particulates have a diameter of about 0.5 micron or less, the d 99  is about 1 microns or less, meaning 99% of the total volume of the first particulates have a diameter equal to or less than about 1 micron; and the d 50  is between 0.05 microns and 0.4 microns, meaning 50% of the total volume of the first particulates have a diameter equal to or less than a value between 0.05 microns and about 0.4 microns.  
     
     
         26 . The method of  claim 21 , wherein the first particulates comprise one or more of copper ferricyanide, copper ferricyanate, copper carbonate, copper borate, copper silicate, copper fluorosilicate, copper thiocyanate, copper boride, or combinations thereof.  
     
     
         27 . The method of  claim 21 , wherein the first particulates comprise one or more of zinc hydroxide; basic zinc carbonate, basic zinc phosphate, zinc borate, or combinations thereof.  
     
     
         28 . The method of  claim 27 , wherein d 96  of these first particulates is about 0.5 micron or less, meaning 96 percent of the total volume of the first particulates have a diameter of about 0.5 micron or less, the d 99  is about 1 microns or less, meaning 99% of the total volume of the first particulates have a diameter equal to or less than about 1 micron; and the d 50  is between 0.05 microns and 0.4 microns, meaning 50% of the total volume of the first particulates have a diameter equal to or less than a value between 0.05 microns and about 0.4 microns.  
     
     
         29 . The method of  claim 27 , wherein the first particulates comprise zinc borate.  
     
     
         30 . The method of  claim 27 , wherein the aqueous wood preservative slurry further comprises a substantially insoluble organic biocide, wherein at least a portion of the substantially insoluble organic biocide is coated on the first particulates.  
     
     
         31 . The method of  claim 27 , wherein the aqueous wood preservative slurry further comprises a substantially insoluble organic biocide selected from biocidal quaternary ammonium compounds; biocidal azoles; biocidal triazoles, and moldicides, wherein at least 20% by weight of the substantially insoluble organic biocide is coated on the first particulates.  
     
     
         32 . The method of  claim 21 , wherein the first particulates comprise one or more of zinc oxychloride; zinc fluoroborate, zinc carbonate, zinc orthophosphate, zinc fluoride, or combinations thereof.  
     
     
         33 . The method of  claim 32 , wherein the aqueous wood preservative slurry further comprises a substantially insoluble organic biocide, wherein at least a portion of the substantially insoluble organic biocide is coated on the first particulates.  
     
     
         34 . The method of  claim 32 , wherein the aqueous wood preservative slurry further comprises a plurality of injectable second particulates comprising at least 20% by weight of an injectable solid substantially insoluble organic biocide, wherein the d 96  of these second particulates is about 1 micron or less, meaning 96 percent of the total volume of the second particulates have a diameter of about 1 micron or less, and the d 99  is about 1.5 microns or less, meaning 99% of the total volume of the second particulates have a diameter equal to or less than about 1.5 microns.  
     
     
         35 . The method of  claim 21 , wherein the first particulates comprise solid substantially insoluble organic biocides, wherein the injectable first particulates had been wet-milled in the presence of a liquid comprising a surface active agent and an effective amount of milling beads having a diameter between 0.1 mm and 0.8 mm and a density greater than about 3.5 grams/cm 3 .  
     
     
         36 . The method of  claim 35 , wherein the solid substantially insoluble organic biocides comprises one or more of Chlorothalonil, Metaldehyde, triphenyltin hydroxide, Maneb, Mancozeb, Zineb, Ziram, and Ferbam.  
     
     
         37 . The method of  claim 35 , wherein the solid substantially insoluble organic biocides comprises one or more of biocidal solid imidazolinones, sulfonylureas, triazolopyrimidine sulfonamides, aryloxyphenoxy propionates, triazines, chloroacetanilides, pyrazoles, and diphenyl ethers.  
     
     
         38 . The method of  claim 35 , wherein the solid substantially insoluble organic biocides comprises one or more of amitraz, azinphos-ethyl, azinphos-methyl, benzoximate, fenobucarb, gamma-HCH, methidathion, deltamethrin, dicofol, dioxabenzafos, dioxacarb, dinobuton, endosulfan, bifenthrin, binapacryl, bioresmethrin, chlorpyrifos, chlorpyrifos-methyl, EPNethiofencarb, cyanophos, cyfluthrin, tetradifon, cypermethrin, tralomethrin, bromophos, N-2,3-dihydro-3-methyl-1,3-thiazol-2-ylidene-xylidene, 2,4-parathion methyl, bromopropylate, butacarboxim, butoxycarboxin, chlordimeform, phosalone, chlorobenzilate, phosfolan, chloropropylate, phosmet, chlorophoxim, promecarb, fenamiphos, quinalphos, resmethrin, temephos, pirimiphos-ethyl, tetramethrin, pirimiphos-methyl, xylylcarb, profenofos, acrinathrin, propaphos, allethrin, propargite, benfuracarb, propetamphos, bioallethrin, pyrachlofos, bioallethrin S, tefluthrin, bioresmethrin, terbufos, buprofezin, tetrachlorinphos, chlorfenvinphos, tralomethrin, chlorflurazuron, triazophos, chlormephos, pyrachlofos, tefluthrin, terbufos, tetrachlorinphos, cycloprothrin, betacyfluthrin, cyhalothrin, cambda-cyhalothrin, tralomethrin, alpha-cypermethrin, triazophos, beta-cypermethrin, cyphenothrin, demeton-S-methyl, dichlorvos, disulfoton, edifenphos, empenthrin, esfenvalerate, ethoprophos, etofenprox, etrimphos, fenazaquin, fenitrothion, fenthiocarb, fenpropathrin, fenthion, fenvalerate, flucythrinate, flufenoxuron, tau-fluvalinate, formothion, hexaflumuron, hydroprene, isofenphos, isoprocarb, isoxathion, malathion, mephospholan, methoprene, methoxychlor, mevinphos, permethrin, phenothrin, phenthoate, benalaxyl, biteranol, bupirimate, cyproconazole, carboxin, tetraconazole, dodemorph, difenoconazole, dodine, dimethomoph, fenarimol, diniconazole, ditalimfos, ethoxyquin, myclobutanil, etridiazole, nuarimol, fenpropidin, oxycarboxin, fluchloralin, penconazole, flusilazole, prochloraz, imibenconazole, tolclofos-methyl, myclobutanil, triadimefon, propiconazole, triadimenol, pyrifenox, azaconazole, tebuconazole, epoxyconazole, tridemorph, fenpropimorph, triflumizole, 2,4-D esters, diclofop-methyldiethatyl, 2,4-DB esters, dimethachlor, acetochlor, dinitramine, aclonifen, ethalfluralin, alachlor, ethofumesate, anilophos, fenobucarb, benfluralin, fenoxapropethyl, benfuresate, fluazifop, bensulide, fluazifop-P, benzoylprop-ethyl, fluchloralin, bifenox, flufenoxim, bromoxynil esters, flumetralin, bromoxynil, flumetralin, butachlor, fluorodifen, butamifos, fluoroglycofen ethyl, butralin, fluoroxypyr esters, butylate, carbetamide, chlornitrofen, chlorpropham, cinmethylin, clethodim, clomazone, clopyralid esters, CMPP esters, cycloate, cycloxydim, desmedipham, dichlorprop esters, flurecol butyl, flurochloralin, haloxyfop, ethoxyethyl, haloxyfop-methyl, ioxynil esters, isopropalin, MCPA esters, mecoprop-P esters, metolachlor, monalide, napropamide, nitrofen, oxadiazon, oxyfluorfen, phenisopham, phenmedipham, picloram esters, pretilachlor, profluralin, propachlor, propanil, propaquizafop, pyridate, quizalofop-P, triclopyr esters, and tridiphane.  
     
     
         39 . The method of  claim 35 , wherein the solid substantially insoluble organic biocides comprises one or more of diuron, chlorotoluron, simazine, atrazine, carbendazime, maneb, mancozeb, fentin hydroxide, and endosulfan.  
     
     
         40 . The method of  claim 39 , wherein the injectable first particulates had been wet-milled in the presence of a liquid comprising a surface active agent and an effective amount of milling media, wherein at least 25% by weight of the milling media comprises milling beads having a diameter between 0.2 mm and 0.7 mm and a density greater than about 5.5 grams/cm 3 .  
     
     
         41 . The method of  claim 35 , wherein the solid substantially insoluble organic biocides comprises one or more of chlorothalonil, copper thiocyanate, zinc pyrithione, and 4,5-dicholo-2-n-octyl-4-isothiazolin-3-one.  
     
     
         42 . The method of  claim 41 , wherein the injectable first particulates had been wet-milled in the presence of a liquid comprising a surface active agent and an effective amount of milling media, wherein at least 25% by weight of the milling media comprises milling beads having a diameter between 0.2 mm and 0.7 mm and a density greater than about 5.5 grams/cm 3 .  
     
     
         43 . The method of  claim 35 , wherein the aqueous wood preservative slurry further comprises a second substantially insoluble organic biocide, wherein at least a portion of the second substantially insoluble organic biocide is coated on the first particulates.  
     
     
         44 . The method of  claim 21 , wherein the first particulates comprise zinc carbonate, wherein the aqueous wood preservative slurry further comprises a plurality of injectable second particulates comprising at least 20% by weight of one or more of zinc hydroxide, copper hydroxide, copper borate, basic copper carbonate, or mixture thereof.  
     
     
         45 . A method of preserving wood comprising the steps of 
 A) providing an aqueous wood preservative slurry comprising: 
 a plurality of injectable first particulates comprising one or more of copper(I) oxide, a sparingly soluble copper salt, zinc oxide, a sparingly soluble zinc salt, iron oxide, a first solid substantially insoluble organic biocide, or any combination thereof, wherein the d 96  of the first particulates is about 1 micron or less, meaning 96 percent of the total volume of the first particulates have a diameter of about 1 micron or less, the d 99  is about 1.5 microns or less, meaning 99% of the total volume of the first particulates have a diameter equal to or less than about 1.5 microns; and the d 50  is greater than 0.02 microns, meaning 50% of the total volume of the first particulates have a diameter greater than 0.02 microns, wherein the first particulates comprise a second substantially insoluble organic biocide disposed on the surface of the first particulates, wherein the second substantially insoluble organic biocide is different from the first substantially insoluble organic biocide, if any; and  
   B) injecting the aqueous wood preservative slurry into wood.    
     
     
         46 . The method of  claim 45 , wherein the d 96  of these second particulates is about 0.5 micron or less, meaning 96 percent of the total volume of the second particulates have a diameter of about 0.5 micron or less, and the the d 50  is between about 0.05 microns and about 0.4 microns, meaning 50% of the total volume of the second particulates have a diameter equal to or less than a value between about 0.05 microns and about 0.4 microns.  
     
     
         47 . The method of  claim 45 , wherein the injectable first particulates had been wet-milled in the presence of a liquid comprising a surface active agent and an effective amount of milling media, wherein at least 25% by weight of the milling media comprises milling beads having a diameter between 0.2 mm and 0.7 mm and a density greater than about 5.5 grams/cm 3 .