U.S. patent application number 16/216552 was filed with the patent office on 2019-08-15 for wood preservative and method for producing same.
The applicant listed for this patent is Koppers Performance Chemicals Inc.. Invention is credited to John Horton, Peter Tham, Jun Zhang.
Application Number | 20190246643 16/216552 |
Document ID | / |
Family ID | 60857191 |
Filed Date | 2019-08-15 |
United States Patent
Application |
20190246643 |
Kind Code |
A1 |
Zhang; Jun ; et al. |
August 15, 2019 |
WOOD PRESERVATIVE AND METHOD FOR PRODUCING SAME
Abstract
A synergistic aqueous wood preservative composition comprising a
copper compound and penflufen. The copper compounds of the
compositions of the invention may be soluble, partially solubilized
or micronized particles. The penflufen of the compositions of the
invention may be solubilized, emulsified or particulate. The wood
preservative compositions of the present invention are surprisingly
provided as stable dispersions and confer surprising and unexpected
resistance to treated wood and wood products.
Inventors: |
Zhang; Jun; (Peachtree City,
GA) ; Tham; Peter; (Morrow, GA) ; Horton;
John; (Peachtree City, GA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Koppers Performance Chemicals Inc. |
Pittsburgh |
PA |
US |
|
|
Family ID: |
60857191 |
Appl. No.: |
16/216552 |
Filed: |
December 11, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15840877 |
Dec 13, 2017 |
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16216552 |
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62437372 |
Dec 21, 2016 |
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62435504 |
Dec 16, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
B27K 3/38 20130101; B27K
3/007 20130101; A01N 25/04 20130101; B27K 3/52 20130101; B27K
3/0207 20130101; B27K 3/343 20130101; A01N 59/20 20130101; B27K
2240/20 20130101; B27K 3/30 20130101; B27K 5/0055 20130101; B27K
3/42 20130101; B27K 3/08 20130101; A01N 43/56 20130101; B27K 3/22
20130101; B27K 3/20 20130101; B27K 3/163 20130101; B27K 3/005
20130101; A01N 43/56 20130101; A01N 59/20 20130101 |
International
Class: |
A01N 43/56 20060101
A01N043/56; A01N 59/20 20060101 A01N059/20; B27K 3/42 20060101
B27K003/42; B27K 3/08 20060101 B27K003/08; B27K 3/22 20060101
B27K003/22; A01N 25/04 20060101 A01N025/04; B27K 3/52 20060101
B27K003/52; B27K 3/38 20060101 B27K003/38 |
Claims
1-96. (canceled)
97. A wood preservative composition comprising: a. a copper
compound; b. penflufen; and c. an aqueous carrier; in a
copper:penflufen ratio from about 1:1 to about 500:1.
98. The wood preservative composition of claim 97, wherein the wood
preservative composition is a concentrate, or a diluted treating
solution.
99. The wood preservative composition of claim 97, wherein the
copper compound is micronized.
100. The wood preservative composition of claim 97, wherein the
penflufen is micronized.
101. The wood preservative composition of claim 99, wherein the
penflufen is micronized.
102. The wood preservative composition of claim 101, further
comprising a dispersant.
103. The wood preservative composition of claim 101, wherein the
micronized copper and/or micronized penflufen in the wood
preservative have a mean particle size between about 5 to 5000
nanometers.
104. The wood preservative composition of claim 101, wherein the
wood preservative composition is a stable composition.
105. The wood preservative composition of claim 104, wherein the
mean particle size of the micronized copper and/or micronized
penflufen mixture in the wood preservative composition varies by
less than 50 nanometers after storage from week one to 6 months at
24.degree. C.
106. The wood preservative composition of claim 97, wherein the
penflufen is emulsified.
107. The wood preservative composition of claim 97, wherein the
penflufen is dissolved in the aqueous carrier by the addition of a
non-aqueous solvent.
108. The wood preservative composition of claim 100, wherein the
micronized penflufen has a particle size between about 5 to 5000
nanometers.
109. The wood preservative composition of claim 108, wherein the
wood preservative composition is a stable composition.
110. The wood preservative composition of claim 109, wherein the
mean particle size of the micronized penflufen in the wood
preservative composition varies by less than 50 nanometers after
storage from week one to 6 months at 24.degree. C.
111. The wood preservative composition of claim 102, wherein the
dispersant is polymeric.
112. The wood preservative composition of claim 111, wherein the
dispersant is selected from the group consisting of a salt of
naphthalene sulfonate condensate, a salt of sulfonated naphthalene
formaldehyde condensate, and sulfonated naphthalene formaldehyde
polymer admixture.
113. The wood preservative composition of claim 97, wherein said
wood preservative composition exhibits a synergistic effect in
resisting decay of a sapwood species of wood by brown rot fungi in
a soil-block test according to American Wood Protection Association
Standard E10-2015, compared to the use of copper alone and
penflufen alone.
114. The wood preservative composition of claim 113, wherein the
brown rot fungi is selected from the group consisting of
Gloeophyllum trabeum, Fibroporia radiculosa, Postia placenta and
Coniophora Postia puteana.
115. The wood preservative composition claim 113, wherein the
sapwood species is southern yellow pine.
Description
[0001] This application is a divisional of U.S. patent application
Ser. No. 15/840,877, filed Dec. 13, 2017, which claims priority to
U.S. Provisional Application No. 62/435,504 filed Dec. 16, 2016,
and U.S. Provisional Application No. 62/437,372 filed Dec. 21,
2016, each of which is incorporated by reference in its entirety
herein.
FIELD OF THE INVENTION
[0002] The present invention relates to biocidal compositions,
particularly wood preservative compositions comprising one or more
copper compounds and penflufen. More particularly, the invention
relates to a method of manufacture of particulate-based biocidal
compositions capable of being injected into wood, the biocidal
compositions, methods of preserving wood using the compositions,
and wood treated with the compositions of this invention.
BACKGROUND OF THE INVENTION
[0003] Copper compounds are common biocides for the protection of
wood or wood products from fungal decay. Compositions comprising
copper compounds alone, however, cannot be used as wood
preservative treatments because the presence of copper-tolerant
fungi in wood prevents such compositions from being effective.
[0004] The prior art discloses a variety of pyrazole-based organic
biocides. For example, in U.S. patent application Ser. No.
13/880,619, Pub. No. US2014/0079806, penflufen was disclosed as a
fungicide for the treatment of wood against basidiomycetes.
However, some fungi are tolerant of pyrazole fungicides.
[0005] Different approaches to the problem of fungal tolerance have
been reported. For example, in U.S. patent application Ser. No.
13/880,985, Pub. No. US2014/0088041, penflufen mixtures were
disclosed as fungicides for the protection of industrial materials.
In U.S. patent application Ser. No. 15/177,845, Pub. No.
US2016/0295863, penflufen mixtures were also disclosed as
fungicides for the protection of industrial materials.
[0006] The inventors have surprisingly discovered that wood
preservative compositions comprising particles of one or more
copper compound and penflufen effectively prevent fungal decay in
treated wood or wood products. Also surprisingly, the inventors
have discovered that the wood preservative compositions comprising
one or more copper compounds and penflufen exhibit a synergistic
effect in resisting decay of sapwood species of wood by brown rot
fungi.
[0007] The inventors have also surprisingly discovered a method of
making wood preservative compositions comprising micronized
particles of one or more copper compounds and penflufen.
Compositions comprising micronized particles frequently suffer from
aggregation or other morphological instability, but the wood
preservative compositions produced according to the present
invention are surprisingly stable under storage conditions.
SUMMARY OF THE INVENTION
[0008] When either a copper compound or a pyrazole fungicide is
used alone as a wood preservative composition, only certain wood
decay fungi may be controlled. It was surprisingly found that a
copper compound in combination with penflufen provided synergistic,
broad spectrum control.
[0009] In certain embodiments, the invention is directed to methods
of treating wood or a wood product comprising a step of contacting
the wood or wood product with an aqueous wood preservative
composition, which exhibits a synergistic effect in resisting
fungal decay. The aqueous wood preservative composition itself
comprises an aqueous carrier, a copper compound and penflufen in a
copper:penflufen ratio of between about 1:1 to about 500:1. In
other embodiments, the invention is directed to the wood
preservative composition itself.
[0010] In certain embodiments, the aqueous wood preservative
composition comprises a micronized copper compound. In a preferred
embodiment, the micronized copper compound has a particle size of 5
to 5000 nanometers.
[0011] In certain embodiments, the aqueous wood preservative
composition comprises penflufen. In a preferred embodiment,
penflufen is in a micronized form and the micronized penflufen has
a particle size of 5 to 5000 nanometers. In another preferred
embodiment, penflufen is either solubilized, emulsified or
encapsulated in a polymer matrix.
[0012] In certain embodiments, the aqueous wood preservative
composition comprises both a micronized copper compound and
penflufen. In one embodiment, the aqueous wood preservative
composition comprises both a micronized copper compound and
emulsified penflufen. In another embodiment, the aqueous wood
preservative composition comprises both a micronized copper
compound and micronized penflufen. In a preferred embodiment, the
micronized copper compound and/or the micronized penflufen has a
particle size of 5 to 5000 nanometers. In another preferred
embodiment, the particle size of the micronized copper compound
and/or the micronized penflufen varies by less than 50 nanometers
after storage from week one to 6 months at 24.degree. C. In another
preferred embodiment, the present wood preservative composition can
further be used in combination with other known preservative
chemicals, including boron based preservatives, such as boric acid,
sodium salt of borates; triazole compounds, pentachlorophenol, and
sodium fluoride. Triazoles of the wood preservative formulations of
the invention include, but are not limited to epoxiconazole,
triadimenol, propiconazole, prothioconazole, metconazole,
cyproconazole, tebuconazole, flusilazole, paclobutrazol,
fluconazole, isavuconazole, itraconazole, voriconazole,
pramiconazole, ravuconazole, and posaconazole.
[0013] In certain embodiments, the aqueous wood preservative
composition comprises a solubilized copper compound. In other
embodiments, the aqueous wood preservative composition used in the
claimed method of treating wood or a wood product comprises
emulsified penflufen or soluble penflufen. In another preferred
embodiment, the present composition can further comprise a boron
compound, such as boric acid, sodium salt of borates; a triazole
compound, or pentachlorophenol. Triazoles of the wood preservative
formulations of the invention include, but are not limited to
epoxiconazole, triadimenol, propiconazole, prothioconazole,
metconazole, cyproconazole, tebuconazole, flusilazole,
paclobutrazol, fluconazole, isavuconazole, itraconazole,
voriconazole, pramiconazole, ravuconazole, and posaconazole.
[0014] In certain embodiments, the invention is direct to methods
of treating wood or a wood product comprising a step of contacting
the wood or wood product with an aqueous wood preservative
composition, as described above. The treated wood or wood product
in this embodiment retains penflufen in an amount between about 4
to 200 g/m.sup.3. In a preferred embodiment, the treated wood or
wood product in this embodiment retains penflufen in an amount
between about 8 to 100 g/m.sup.3 and in a more preferred embodiment
in an amount between about 8 to 80 g/m.sup.3.
[0015] In certain embodiments, the aqueous wood preservative
composition, applied to achieve a retention in an amount between
about 4 to 200 g/m.sup.3, resists decay of sapwood species of wood
by brown rot fungi in a soil-block test according to American Wood
Protection Association Standard E10-2015, such that the treated
wood or wood product loses between less than 2% and 20% mean
weight. In certain embodiments, the brown rot fungi are selected
from the group consisting of Gloeophyllum trabeum, Fibroporia
radiculosa, Postia placenta and Coniophora Postia puteana. In
certain embodiments, the sapwood species is southern yellow
pine.
[0016] In certain embodiments, the invention is directed to wood or
a wood product comprising a copper compound and penflufen, wherein
the copper:penflufen ratio is between about 1:1 to about 500:1 and
wherein the wood or wood product contains the penflufen in an
amount between about 4 to 200 g/m.sup.3. In a preferred embodiment,
the invention is directed to wood or a wood product comprising a
copper compound and penflufen, wherein the copper:penflufen ratio
is between about 1:1 to about 500:1 and wherein the wood or wood
product contains the penflufen in an amount between about 8 to 80
g/m.sup.3.
[0017] A stable micronized penflufen particle dispersion may be
prepared through a milling process. In one embodiment, the milling
process comprises the step of mixing a slurry of penflufen and
dispersant mixture in a solvent, and wet milling of the slurry with
a high density grinding media having a diameter between 0.05 mm and
1.0 mm, preferably between 0.1 mm to 0.5 mm, and a density of 2.5
g/cc or higher, preferably 3.5 g/cc or higher. The milled penflufen
dispersion has a particle size in the range of 5 nanometers to 5000
nanometers (5 microns), specifically with a size of d.sub.95 of
about 5 microns or less and a d.sub.50 of greater than 20
nanometers (0.02 microns).
[0018] In certain embodiments, the dispersant used in the milling
is a polymeric dispersant. In a preferred embodiment, the
dispersant is a salt of naphthalene sulfonate condensate, or a salt
of sulfonated naphthaleneformaldehyde condensate, or sulfonated
naphthalene formaldehyde polymer admixture. In certain embodiments,
the weight ratio of the penflufen to the dispersant varies from
1:10 to about 1000:1, and preferred ratio is about 1:1 to about
100:1.
[0019] The prepared micronized penflufen compositions are stable
under high-shear mixing and subject to multiple pressure
treatments. In addition, the milled penflufen particles can be
mixed with compositions containing copper compounds and the mixture
of penflufen/copper is also stable under high shear mixing and
subject to multiple pressure treatment. Upon storage, the mean
particle size, the d.sub.95 and the d.sub.50 of the prepared
penflufen compositions remain stable from the first month to the
sixth month.
DETAILED DESCRIPTION OF THE INVENTION
[0020] Unless otherwise specified, all compositions are given in
"percent", where the percent is the percent by weight based on the
total weight of the entire component, e.g., of the particle, or to
the injectable composition. In the event a composition is defined
in "parts" of various components, this is parts by weight wherein
the total number of parts in the composition is between 90 and
110.
[0021] As used herein, the term "resistant to fungal decay"
indicates that the wood or wood product is suitable for use in
residential construction under relevant building codes. As used
herein, the term "stable" used in reference to a wood preservative
composition means that wood can be pressure treated with the
"stable" composition without fallout on the surface of the
wood.
[0022] As used herein, the term "micronized" refers to particulate
material that has been milled to a relatively small particle size.
Thus, a micronized compound is also a dispersed or particulate
compound. The term "micronized" is not intended to indicate a
specific particle size or range of particle sizes, although the
micronized particles of the present invention tend to have particle
sizes less than 10 .mu.m in diameter.
[0023] As used herein, particle diameters may be expressed as
"d.sub.xx" where the "xx" is the weight percent (or alternately the
volume percent) of that component having a diameter equal to or
less than the d.sub.xx. The d.sub.50 is the diameter where 50% by
weight of the component is in particles having diameters equal to
or lower than the d.sub.50, while just under 50% of the weight of
the component is present in particles having a diameter greater
than the d.sub.50. Particle diameter is preferably determined by
Stokes Law settling velocities of particles in a fluid, for example
with a Model LA 700 or a CAPA.TM. 700 sold by Horiba and Co. Ltd.,
or a Sedigraph.TM. 5100 T manufactured by Micromeritics, Inc.,
which uses x-ray detection and bases calculations of size on
Stoke's Law, to a size down to about 0.2 microns. Smaller sizes are
preferably determined by a dynamic light scattering method,
preferably with a Coulter.TM. counter.
[0024] Generally, the copper or copper compounds of the present
invention are prepared from: but are not limited to copper metal,
cuprous oxide (a source of copper (I) ions), cupric oxide (a source
of copper (II) ions), copper hydroxide, copper carbonate, basic
copper carbonate, copper oxychloride, copper 8-hydroxyquinolate,
copper dimethyldithiocarbamate, copper omadine, copper borate or
basic copper borates, copper residues (copper metal byproducts) or
any suitable copper source. Copper compounds disclosed in the
current invention can be either particulate copper dispersion or
soluble copper solution. In the case of particulate copper
dispersion, copper compounds are dispersed with an aid of polymeric
dispersant(s). In the case of soluble copper solution, copper
compounds may be solubilized by contacting them with a solubilizing
agent. Examples of solubilizing agents include, but are not limited
to, alkanolamines, such as, for example, monoethanolamine,
ethanolamine, diethanolamine, triethanolamine and ammonia. In one
embodiment, copper compounds are prepared in a micronized
dispersion.
[0025] In another embodiment, the particles comprise at least about
20%, 30%, 40%, 50%, 60%, 70% or 75% of the weight of the any of
these copper compounds. The most preferred copper compounds are
copper hydroxide and basis copper carbonate.
[0026] In certain embodiments, the aqueous wood preservative
composition comprises one or more copper compound and penflufen,
where the copper compound can be either micronized or amine
solubilized. In one embodiment, the aqueous wood preservative
composition comprises a solubilized copper compound and emulsified
penflufen. In another embodiment, the aqueous wood preservative
composition comprises a micronized copper compound and emulsified
penflufen. In another embodiment, the aqueous wood preservative
composition comprises both a micronized copper compound and
micronized penflufen. In a preferred embodiment, the micronized
copper compound and/or the micronized penflufen has a particle size
of 5 to 5000 nanometers. In another embodiment, wood or a wood
product is impregnated with dispersed particles of one or more
copper compounds and dispersed penflufen particles, which comprise
the biocidal compositions of the invention.
[0027] In one embodiment, the dispersants used in the
wood-preservative compositions of the present invention include,
but are not limited to cationic, non-ionic or anionic dispersants,
acrylic copolymers, an aqueous solution of copolymers with pigment
affinity groups, polycarboxylate ethers, modified polyacrylates,
acrylic polymer emulsions, modified acrylic polymers, poly
carboxylic acid polymers and their salts, modified poly carboxylic
acid polymers and their salts, fatty acid modified polyesters,
aliphatic polyethers or modified aliphatic polyethers,
polyetherphosphates, solution of polycarboxylate ethers, sodium
polyacrylates, sodium polymethacrylates, modified polyether or
polyester with pigment affinity groups, fatty acid derivatives,
urethane copolymers or modified urethane copolymers, acrylic
acid/maleic acid copolymers, polyvinyl pyrrolidones or modified
polyvinyl pyrrolidones, modified maleic anhydride/styrene
copolymers, lignins and the like.
[0028] Preferably, the dispersants used in the wood-preservative
compositions of the present invention are polymeric dispersants. In
one embodiment, the polymeric dispersants contain at least one
pigment affinity group capable of binding to a solid particle. In
another embodiment, the polymeric dispersants stabilize a solid
particle. Preferably, the polymeric dispersants used in the
wood-preservative compositions of the present invention are
modified polycarboxylate ethers, modified poly carboxylic acid
polymers and their salts, solutions of polycarboxylate ethers and
modified polyethers or polyesters with pigment affinity groups.
[0029] In a first embodiment of the invention, the dispersant is a
non-ionic surfactant. Non-ionic surfactants are materials which
carry no discrete charge when dissolved or suspended in aqueous
media. The hydrophilicity of the surfactant is provided by hydrogen
bonding with water molecules. Oxygen atoms and hydroxyl groups
readily form strong hydrogen bonds. Such hydrogen bonding can
provide a dispersion (suspensibility) or solubilization of the
fungicide in neutral or alkaline media. Non-ionic materials useful
for the present invention further include polyalkylene oxide block
copolymers. Such block copolymers typically have at least one block
segment comprising -(AO).sub.x--, wherein AO represents an
oxyalkylene moiety and x is a number of about 1 to about 100.
Preferably, AO represents either an ethylene oxide moiety or a
propylene oxide moiety. The -(AO).sub.x-- block must be attached to
a functional group differing in hydrophilicity (or
hydrophobicity).
[0030] Exemplary surfactants/dispersants include ethoxylates of
castor oil (ethyleneoxide degree of polymerization 30 60 ethoxy
moieties); ethoxylates of tridecylalcohol(ethyleneoxide degree of
polymerization 4 20); ethoxylates of a C10 C14 alcohol
(ethyleneoxide degree of polymerization 4 20); ethoxylates of
nonylphenol (ethyleneoxide degree of polymerization 6 50);
ethoxylates of a fatty alcohol (ethyleneoxide degree of
polymerization 3 20); ethoxylates of a sorbitol ester
(ethyleneoxide degree of polymerization 10 40); ethoxylates of a
sorbitan-tallate (ethyleneoxide degree of polymerization 10 40);
ethoxylates of a tristyrphenol (ethyleneoxide degree of
polymerization 3 20); ethoxylates of a isodecyl alcohol
(ethyleneoxide degree of polymerization 3 10); ethoxylates of a
isododecyl alcohol (ethyleneoxide degree of polymerization 3 10),
or mixtures thereof.
[0031] A group of non-ionic surfactants useful in the context of
the present invention includes a polycondensation product
containing an alkylene glycol as a monomer. Exemplary compounds
include a polyethylene glycol, a polypropylene glycol or a block
polymer of ethylene glycol and propylene glycol. The degree of
polymerization of these compounds is preferably in the range of
about 5 to about 1,000, and more preferably in the range of from
about 10 to about 500.
[0032] Non-ionic dispersants further include polyalkylene oxide
block copolymers. Such block copolymers typically have at least one
block segment comprising -(AO).sub.x--, wherein AO represents an
oxyalkylene moiety and x is a number of about 1 to about 100.
Preferably, AO represents either an ethylene oxide moiety or a
propylene oxide moiety. The -(AO).sub.x-- block must be attached to
a functional group differing in hydrophilicity (or hydrophobicity).
Such copolymers can be derived from higher alkylene oxides such as
ethylene oxide, propylene oxide, butylene oxide, styrene oxide,
etc. Such block copolymers typically contain a polyethylene oxide
block which is relatively hydrophilic combined with another
polyalkylene oxide block which is typically hydrophobic resulting
in surfactant properties. Another non-ionic surfactant includes
polyoxypropylene-polyoxyethylene block copolymer surfactants. Those
surfactants comprising a center block of polyoxypropylene units
(PO), and having a block of polyoxyethylene (EO) units to each side
of the center PO block, are generally useful in the context of this
invention, particularly where the average molecular weight ranges
from about 900 to 14,000, and the percent of weight E0 ranges from
about 10 to 80. These types of surfactants are sold commercially as
"Pluronics."
[0033] A second, and preferred, group of non-ionic surfactants
useful in the context of the present invention includes etherified
compound of the first group of compounds and an aliphatic alcohol.
In such a manner, a dispersant having a polyethylene oxide block
which is relatively hydrophilic combined with a long alkyl section,
e.g., C6 to C30, which is typically hydrophobic can be obtained,
resulting in surfactant properties. Exemplary compounds include
polyethylene glycol oleyl ether (ethyleneoxide degree of
polymerization 4 to 50), polyethylene glycol cetyl ether
(ethyleneoxide degree of polymerization 4 to 50), polyethylene
glycol stearyl ether (ethyleneoxide degree of polymerization 4 to
50), polyethylene glycol lauryl ether (ethyleneoxide degree of
polymerization 4 to 50), polyethylene glycol tridecyl ether
(ethyleneoxide degree of polymerization 4 to 50), polyethylene
glycol nonylphenyl ether (ethyleneoxide degree of polymerization 4
to 50), polyethylene glycol octylphenyl ether (ethyleneoxide degree
of polymerization 4 to 50), and the like. A preferred degree of
polymerization for compounds in this class is in the range of from
4 to 20, for example between about 6 to about 12.
[0034] A subgroup of compounds is an etherified compound of the
above-mentioned group of compounds and a higher fatty acid.
Exemplary compounds include polyethylene glycol monolaurate
(ethyleneoxide degree of polymerization 2 to 50), polyethylene
glycol monostearate (ethyleneoxide degree of polymerization 2 to
50), polyethylene glycol monooleate (ethyleneoxide degree of
polymerization 2 to 50), and the like.
[0035] Other non-ionic surfactants include
polyoxypropylene-polyoxyethylene block copolymer surfactants. Those
surfactants comprising a center block of polyoxypropylene units
(PO), and having a block of polyoxyethylene (EO) units to each side
of the center PO block, are generally useful in the context of this
invention, particularly where the average molecular weight ranges
from about 900 to 14,000, and the percent of weight EO ranges from
about 10 to 80.
[0036] In addition, hydrophobically modified pluronic surfactants
can be employed, wherein a modifying group (R) such as a methyl,
ethyl, propyl, butyl, benzyl, etc. may be capping the terminal
o.times.y alkaline group; e.g.,
R-(EO).sub.n--(PO).sub.m-(EO).sub.n--R.
[0037] Exemplary dispersants include linear alcohol alkoxylates,
such as the linear alcohol ethoxylates or an
ethyoxylated/propoxylated block. If desired, the alcohol alkoxylate
is suitably end-capped with a lower alkyl group, and such a product
is commercially available as POLY-TERGENT SLF-18 surfactant,
available from BASF Corporation. Other useful anionics are
polycarboxylated alcohol alkoxylates, preferably those selected
from the group consisting of the acids or organic or inorganic
salts of the following: polycarboxylated linear alcohol
alkoxylates, polycarboxylated branched alcohol alkoxylates,
polycarboxylated cyclic alcohol alkoxylates, and combinations
thereof. Nonionic surfactants include, for example: alkylphenol
ethoxylates, for example, ethoxylated nonyl phenol, alkylphenol
ethoxylate or nonylphenol ethoxylate containing from about 1 to
about 20 or more moles of ethylene oxide per mole of phenol.
[0038] A preferred group of compounds includes phosphate (or less
preferably sulfate or sulfonate) ester of any of the
above-mentioned groups of compounds. Exemplary compounds include
polyethylene glycol oleyl ether phosphate (ethyleneoxide degree of
polymerization 4 to 50), polyethylene glycol cetyl ether phosphate
(ethyleneoxide degree of polymerization 4 to 50), polyethylene
glycol stearyl ether phosphate (ethyleneoxide degree of
polymerization 4 to 50), polyethylene glycol lauryl ether phosphate
(ethyleneoxide degree of polymerization 4 to 50), polyethylene
glycol tridecyl ether phosphate (ethyleneoxide degree of
polymerization 4 to 50), polyethylene glycol nonylphenyl ether
phosphate (ethyleneoxide degree of polymerization 4 to 50),
polyethylene glycol octylphenyl ether phosphate (ethyleneoxide
degree of polymerization 4 to 50), and the like.
[0039] In certain embodiment, the dispersant to copper and/or
penflufen ratio varies from about 1:500 to about 1000:1. The
preferred dispersant to copper and/or penflufen ratio is about
1:100 to about 10:1, and the most preferred ratio about 5:100 to
1:1.
[0040] Leaching is a function of particle size and the solubility
of the material. Larger size particles have lower leach rates,
while particles in a size range from 1 to 10 nanometers under
certain circumstances will not have a leach rate much different
than that of an injected and dried copper salt solution. In
preferred embodiments of this invention, the d.sub.50 is at least
0.04 microns, meaning at least 50% by weight of the particulates
have a size greater than 40 nanometers. In more preferred
embodiments, the d.sub.50 is 0.10 microns or greater. In one
preferred embodiment, at least 80% by weight of the particulates
have a size between 0.05 microns and 1.0 microns.
[0041] Leaching is not the only mechanism whereby material can be
flushed from wood. Because the material is in particulate form,
there is a possibility that particulates will be flushed from the
wood during the final vacuum process. Evidence suggests that very
small substantially spherical nanoparticles, i.e., spherical
particles of size 5 to 20 nanometers, can migrate freely through a
wood matrix. However, while said particles are easy to inject, they
are also clearly easily transported through wood and would be
easily flushed from the wood during the final vacuum stage of
vacuum/pressure impregnation process. Therefore, in preferred
embodiments of the invention the material is substantially free of
substantially spherical particulates, wherein the particle diameter
is less than about 20 nanometers, particularly less than 15
nanometers. By substantially free we mean the d.sub.20 is greater
than 0.02 microns.
[0042] Another key aspect of the invention is to make a variety of
biocidal particulate slurry compositions available that are
injectable into wood, thereby serving as a particulate wood
preservative. Requirements of injectability into wood for
substantially round, e.g., the diameter in one direction is within
a factor of two of the diameter measured in a different direction,
such as would be found in milled particles, are:
[0043] 1) the d.sub.96 is equal to or less than about 1 micron, but
is preferably about 0.7 microns or less, more preferably about 0.5
microns or less, for example equal to or less than about 0.3
microns, or equal to or less than about 0.2 microns;
[0044] 2) the d.sub.99 is equal to or less than about 2 microns,
preferably equal to or less than 1.5 microns, more preferably equal
to or less than about 1 micron; and
[0045] 3) the d.sub.50 is less than 0.5 microns, preferably less
than 0.4 microns, and the d.sub.50 is greater than 0.02 microns,
more preferably greater than 0.05 microns, for example a slurry
composition where the d.sub.50 is between about 0.1 microns and
about 0.3 microns. We believe the first criteria primarily
addresses the phenomena of bridging and subsequent plugging of pore
throats, the second criteria addresses the phenomena of forming a
filter cake, and the third criteria addresses the issue of having
particulates disposed in the wood which have an optimum size to
ensure the treatment has an acceptable bio-activity and lifetime.
Once a pore throat is partially plugged, complete plugging and
undesired buildup generally quickly ensues.
[0046] However, there are minimum preferred particulate diameters
for the wood treatment, which depend somewhat on the compound(s)
that are in the particulates. If a copper compound has a high
solubility, very small particulates having a large surface to mass
ratio will result in too high a copper ion concentration, and too
fast a copper leaching, compared to preferred embodiments of this
invention. Generally, it is preferred that for particulate copper
compounds, the d.sub.20 be above 0.01 microns in diameter,
preferably greater than 0.03 microns, for example greater than 0.06
microns in diameter. While penflufen particles can be smaller, as
these compounds generally exhibit lower solubility in water than do
the copper compounds, nevertheless a preferred minimum d.sub.20 for
a mixture of particulate copper compounds and particulate penflufen
is 0.01 microns.
[0047] Preferred particles comprise at least 30%, preferably at
least 50%, more preferably at least 70%, for example between about
80% and about 98% by weight of total of copper hydroxides,
copper(I) oxide, basic copper carbonates, copper carbonates, copper
oxychloride, basic copper phosphate, basic copper phosphosulfate,
tribasic copper sulfate, alkaline copper nitrate, basic copper
borate, copper silicate, or mixtures thereof. The various particles
within a wood preservative can comprise different biocides, even
different copper compounds. For example, a treatment may contain
particles that comprise copper borate or copper borate in
combination with copper hydroxide and/or a basic copper salt,
particularly basic copper carbonate, other particles that comprise
basic copper carbonate, optionally particles that comprise basic
copper phosphate, and even other particles that comprise copper
oxide. The particles having different phases may in preferred
embodiments be of different sizes, depending on the copper material
present.
[0048] In one embodiment, exemplary wood preservatives have a
d.sub.50 equal to or smaller than 0.5 .mu.m, 0.25 .mu.m, 0.2 .mu.m,
or 0.15 .mu.m. Advantageously, the d.sub.96, and preferably the
d.sub.99, are within a factor of three of the d.sub.50, and very
preferably is less than 1.2 microns. In one embodiment, the
d.sub.50 is at least 25 nanometers, for example, at least 50
nanometers.
[0049] There is a large number of references describing how to make
copper-containing "nanoparticles." These references generally
cannot be used to manufacture the particulates at the desired cost.
One method that is particularly not cost effective is using an
emulsion precipitation or emulsion crystallization technique, where
small particles are allowed to grow in a certain phase of an
emulsion, where the ultimate size of the particle is limited by the
amount of a component in a droplet in the emulsion. Both inorganic
salts and organic biocidal particulates can be formed in this
manner, but not at a cost where such materials would be useful for
foliar applications on crops nor for wood preservation.
[0050] U.S. Pat. No. 4,808,406, the disclosure of which is
incorporated by reference, describes a useful method for producing
finely divided stable cupric hydroxide composition of low bulk
density comprising contacting solutions of an alkali metal
carbonate or bicarbonate and a copper salt, precipitating a basic
copper carbonate-basic copper sulfate to a minimum pH in the range
of greater than 5 to about 6, contacting the precipitate with an
alkali metal hydroxide and converting basic copper sulfate to
cupric hydroxide. Another method of manufacturing the copper
compounds is the method described in U.S. Pat. No. 4,404,169, the
disclosure of which is incorporated by reference. This patent
describes a process of producing cupric hydroxides having stability
in storage if phosphate ions are added to a suspension of copper
oxychloride in an aqueous phase. The copper oxychloride is then
reacted with alkali metal hydroxide or alkaline earth metal
hydroxide, and the cupric hydroxide precipitated as a result of the
suspension is washed and then re-suspended and subsequently
stabilized by the addition of acid phosphate to adjust a pH value
of 7.5 to 9. The suspended copper oxychloride is preferably reacted
in the presence of phosphate ions in an amount of 1 to 4 grams per
liter of the suspension and at a temperature of 20.degree. to
25.degree. C. and the resulting cupric hydroxide is stabilized with
phosphate ions.
[0051] Wet ball milling, with milling media of specified
characteristics, can advantageously modify particle size and
morphology of copper compounds and even solid organic biocides
known to be highly resistant to milling, such as chlorothalonil and
penflufen, to a size where the compounds are readily injectable
into wood. Surprisingly, it has been found that both organic and
inorganic particulates can be readily milled into an injectable
material by wet milling with a milling material such as a 0.3 to a
0.7 mm milling media having density greater than 3 grams/cm.sup.3,
for example equal to or greater than 3.8 grams/cm.sup.3 such as 0.5
mm diameter zirconium silicate, preferably greater than 5.5,
grams/cm.sup.3 provided by a 0.5 mm milling bead of zirconium oxide
which may contain one or more dopants such as cerium and/or
yttrium, and/or magnesia in a stabilizing amount. Additionally,
regardless of the particle size of the feedstock, the particles can
be broken down to injectable size in a matter of minutes to at most
a few hours. Beneficially all injectable formulations for wood
treatment should be wet-milled, even when the "mean particle size"
is well within the range considered to be injectable into wood.
[0052] The milling media, also called grinding media or milling
beads, is central to this invention. The selection of milling media
is expressly not a routine optimization. The use of this media
allows an average particle size and a narrow particle size
distribution that had previously not been obtainable in the art,
nor did the results in the prior art allow one to predict the
unexpected results we obtained. A major contribution of this
invention is a method of preparing a particulate biocide product
having a d.sub.50 equal to or less than about 1 micron, comprising
the steps of: 1) providing the solid inorganic or organic biocide,
and a liquid comprising a surface active agent, to a mill;
providing a milling media comprising an effective amount of milling
beads having a diameter between 0.01 mm and 0.8 mm, preferably
between about 0.1 mm and about 0.7 mm, more preferably between
about 0.1 mm and about 0.5 mm, wherein these milling beads have a
density greater than about 2.5 grams/cm.sup.3, preferably equal to
or greater than 3.5 grams/cm.sup.3, more preferably equal to or
greater than 3.8 grams/cm.sup.3, most preferably equal to or
greater than 5.5 grams/cm.sup.3, for example a zirconia bead having
a density of about 6 grams/cm.sup.3; and 2) wet milling the
material at high speed, for example between 300 and 6000 rpm, more
preferably between 1000 and 4000 rpm, for example between about
2000 and 3600 rpm, where milling speed is provided for a laboratory
scale ball mill, for a time sufficient to obtain a product having a
mean volume particle diameter of about 1 micron or smaller, for
example between about 5 minutes and 300 minutes, preferably from
about 10 minutes to about 240 minutes, and most preferably from
about 15 minutes to about 60 minutes. As little as 5% by volume of
the milling media need be within the preferred specifications for
milling some materials, but better results are obtained if greater
than 10% by weight, preferably greater than 25% by weight, for
example between 40% and 100% by weight of the milling material is
within the preferred specifications. For milling material outside
the preferred specifications, advantageously this material has a
density greater than 3 grams/cm.sup.3 and a diameter less than 4
mm, for example 1 or 2 mm zirconia or zirconium silicate milling
beads.
[0053] The milling media advantageously comprises or consists
essentially of a zirconium-based material. The preferred media is
zirconia (density .about.6 g/cm.sup.3), which includes preferred
variants such as yttria stabilized tetragonal zirconium oxide,
magnesia stabilized zirconium oxide, and cerium doped zirconium
oxide. For some biocides, zirconium silicate (density .about.3.8
g/cm.sup.3) is useful. However, for several biocides such as
chlorothalonil, zirconium silicate will not achieve the required
action needed to obtain the narrow sub-micron range of particle
sizes in several preferred embodiments of this invention. In an
alternate embodiment, at least a portion of the milling media
comprises or consists essentially of metallic material, e.g.,
steel. The milling medium is a material having a density greater
than about 2.5, preferably at least about 3.8, more preferably
greater than about 5.5, for example at least about 6
g/cm.sup.3.
[0054] We believe that density and particle size are the two most
important parameters in the milling media. Preferably the milling
media comprises or consists essentially of particles, having a size
(diameter) between about 0.01 mm and about 0.8 mm, preferably
between about 0.1 mm and about 0.7 mm, for example between about
0.1 mm and 0.5 mm. Also preferably, the milling media can have a
density greater than about 3.5 g/cm.sup.3, preferably greater than
about 5.5 g/cm.sup.3, more preferably greater than about 6
g/cm.sup.3. The zirconium-based milling media useful in the present
invention can comprise or consist essentially of particles having a
diameter (as the term is used in the art) between about 0.1 mm and
about 0.8 mm, preferably between about 0.1 mm and about 0.7 mm, for
example between about 0.1 mm and 0.5 mm.
[0055] Not all the milling media need be the preferred material,
e.g., having a preferred diameter between 0.1 mm and 0.8 mm,
preferably between 0.1 mm and 0.7 mm, more preferably between 0.1
mm and 0.5 mm, and having a preferred density equal to or greater
than 3.5 grams/cm.sup.3, preferably greater than or equal to 5.5
grams/cm.sup.3, more preferably greater than or equal to 6
grams/cm.sup.3. In fact, as little as 10% of this media will
provide the effective grinding. The amount of the preferred milling
media, based on the total weight of media in the mill, can be
between 5% and 100%, is advantageously between 10% and 100%, and is
preferably between 25% and 90%, for example between about 40% and
80%. Media not within the preferred category can be somewhat
larger, say 1 mm to 4 mm in diameter, preferably from 1 mm to 2 mm
in diameter, and advantageously also has a density equal to or
greater than 3.5 grams/cm.sup.3.
[0056] A first aspect of the invention is a method of preparing a
micronized biocide product, e.g., penflufen comprising the steps
of: 1) providing the solid biocide in particle form to a ball mill,
providing a liquid to a mill, and providing a milling media to the
mill, wherein the milling media comprises at least 5%, preferably
at least 10%, more preferably at least 25% by weight of the milling
media having a particle diameter between 0.1 to 0.8 mm, preferably
between 0.1 and 0.5 mm, and having a density equal to or greater
than 3.5 g/cm.sup.3, preferably equal to or greater than 5.5
g/cm.sup.3; and 2) milling the material for a time sufficient to
obtain a product having a mean volume particle diameter d.sub.50 of
about 1 micron or smaller. The mill speed is advantageously fast,
for example from 1000 rpm to about 4000 rpm, and the milling time
is preferably between 10 minutes and 240 minutes.
[0057] Generally, less dense milling media will provide a
relatively larger d.sub.50, which can be useful for foliar
applications. The denser milling media, for example media having a
density greater than 5.5 g/cm.sup.3, provides a smaller d.sub.50.
Surprisingly, varying the milling time has very little effect on
the d.sub.50. The preferred dense milling media is zirconia or
cerium doped zirconia. The zirconium oxide can comprise any
stabilizers and/or dopants known in the art, including, for
example, cerium, yttrium, and magnesium. An alternate useful dense
milling material is steel. Generally, at least 25% by weight of the
milling media must have a density greater than 3.8 and a diameter
between 0.1 and 0.7 mm to reliably obtain injectable particulate
copper compounds.
[0058] Manufacturing injectable solid substantially insoluble
organic biocide particles, e.g., penflufen, can beneficially be
performed by 1) providing the penflufen and a liquid comprising
surface active agents to a mill, and 2) milling the material with a
milling media having a density greater than 2.5 grams/cm.sup.3, for
example milling beads comprising a zirconium oxide having a
diameter between about 0.01 mm and about 0.5 mm, and preferably a
density greater than 3.5 g/cm.sup.3. The invention also encompasses
an organic biocide particulate product, e.g., a penflufen product,
having a d.sub.50 below about 1 micron, typically below about 0.5
microns, and preferably between 0.1 and 0.3 microns, which
advantageously also exhibits a d.sub.50 that is less than about
three times the d.sub.98 preferably less than about two times the
d.sub.98.
[0059] The attainment of the injectable size, which generally
requires both a d.sub.50 below 0.5 microns and a d.sub.98 less than
three times the d.sub.50, was a surprising development. Milling
copper compounds for several days with a 2 mm milling media could
not provide the required particle size distribution, even if the
feed material had a d.sub.50 of less than 0.3 microns. Milling a
milling-resistant organic biocide, such as penflufen, with 1 mm
zirconia provided a penflufen product with a d.sub.50 of 2 to 3
microns. Yet, surprisingly, milling each of these with a preferred
milling media, e.g., zirconia-based milling beads having a diameter
between 0.4 and 0.5 mm, provided each of these products in
injectable sub-micron slurries in under a few hours, often in less
than 30 minutes.
[0060] Advantageously, the liquid comprises one or more dispersants
and/or stabilizers. The presence of these promotes a smaller
d.sub.50 and a narrower particle size distribution, because
agglomeration of particulates is discouraged. Aqueous dispersing
agents for such dispersed solids are well known to those skilled in
the art and include, but are not limited to, nonionic surfactants
such as ethylene oxide/propylene oxide block copolymers, polyvinyl
alcohol/polyvinyl acetate copolymers, polymeric nonionic
surfactants such as the acrylic graft copolymers; anionic
surfactants such as polyacrylates, lignosulfonates, polystyrene
sulfonates, maleic anhydride-methyl vinyl ether copolymers,
naphthalene sulfonic acid formaldehyde condensates, phosphate ester
surfactants such as a tristyrenated phenol ethoxylate phosphate
ester, maleic anhydride-diisobutylene copolymers, anionically
modified polyvinyl alcohol/polyvinylacetate copolymers, and ether
sulfate surfactants derived from the corresponding alkoxylated
nonionic surfactants; cationic surfactants; zwitterionic
surfactants; and the like.
[0061] Penflufen used in the present invention can be prepared in
variety of ways. For example, as a solution in one or more organic
solvents, an emulsion in water by emulsifying the compounds with
the aid of emulsifiers, or as dispersion in particulate form by
dispersing through homogenizer or high speed agitation or through
milling/grinding process, or an encapsulation embed in polymer
matrix or any other chemical and physical means. In one embodiment,
penflufen is prepared as an emulsion concentrate. When prepared as
emulsion or emulsifiable concentrate, penflufen is dissolved in the
mixture solvent(s) and emulsifiers or surfactants. Non-limited
examples of solvents include mineral oils, white spirits,
dichloromethane, hexane, toluene, alcohols such as methanol,
ethanol, benzyl alcohol and 2-propanol, glycols such as ethylene
glycol and propylene glycol, ethers, esters, poly-glycols,
poly-ethers, amides, methylene chloride, acetone, chloroform,
N,N-dimethyl octanamide, N,N-dimethyl decanamide, N-methyl
2-pyrrolidone, n-(n-octyl)-2-pyrrolidone, and combinations of the
above. Emulsifiers can be anionic, cationic, or nonionic or the
combinations. Examples of emulsifiers include, but are not limited
to, ethyoxylated alkylphenols or amines or amides or aryl phenols
or fatty esters, fatty acids and derivatives, ethoxylated alcohols
and derivatives, sulfonated amine or amides and derivatives,
carboxylated alcohol or alkylphenol ethoxylates and derivatives,
glycol ethers or esters. Additional examples of emulsifers can be
found in McCutcheon's Emulsifiers and Detergents, 2016. In another
embodiment, penflufen is prepared as microencapsulated particles.
Microencapsulation of penflufen include steps of preparation of
solutions, homogenization and solvent evaporation. When prepared as
microencapsulation, penflufen is first dissolved in a solvent(s)
followed by addition of a polymer(s) or emulsifier. The mixture is
then homogenized under high shear mixing, and the solvent remained
in the mixture is then evaporated off, and the final
microencapsulation is formed. In a more preferred embodiment,
penflufen is prepared as a micronized dispersion through milling
process.
[0062] The milling of the organic biocides is advantageously
performed in the presence of an aqueous medium containing
surfactants and/or dispersants, such as those known in the art. Use
of other media, including for example polar organic solvents such
as alcohols, generally does not offer added advantage sufficient to
outweigh the cost and associated hazards of milling with solvents.
Because it is now possible to achieve a smaller particle size and a
narrower particle size distribution using the present invention
than was previously known in the art, the number and amount of
stabilizers and/or dispersants are less critical. As used herein,
the term "surface active agent" includes both singular and plural
forms and encompasses generally both stabilizers and dispersants.
The surface active agent may be anionic, cationic, zwitterionic, or
nonionic, or a combination thereof. Generally, higher
concentrations of surface active agents present during milling
result in a smaller particle size.
[0063] Examples of other suitable classes of surface active agents
include, but are not limited to, anionics such as alkali metal
fatty acid salts, including alkali metal oleates and stearates;
alkali metal lauryl sulfates; alkali metal salts of diisooctyl
sulfosuccinate; alkyl aryl sulfates or sulfonates, lignosulfonates,
alkali metal alkylbenzene sulfonates such as dodecylbenzene
sulfonate, alkali metal soaps, oil-soluble (e.g., calcium,
ammonium, etc.) salts of alkyl aryl sulfonic acids, oil soluble
salts of sulfated polyglycol ethers, salts of the ethers of
sulfosuccinic acid, and half esters thereof with nonionic
surfactants and appropriate salts of phosphated polyglycol ethers;
cationics such as long chain alkyl quaternary ammonium surfactants
including cetyl trimethyl ammonium bromide, as well as fatty
amines; nonionics such as ethoxylated derivatives of fatty
alcohols, alkyl phenols, polyalkylene glycol ethers and
condensation products of alkyl phenols, amines, fatty acids, fatty
esters, mono-, di-, or triglycerides, various block copolymeric
surfactants derived from alkylene oxides such as ethylene
oxide/propylene oxide (e.g., PLURONIC.TM., which is a class of
nonionic PEO-PPO co-polymer surfactant commercially available from
BASF), aliphatic amines or fatty acids with ethylene oxides and/or
propylene oxides such as the ethoxylated alkyl phenols or
ethoxylated aryl or polyaryl phenols, carboxylic esters solubilized
with a polyol or polyvinyl alcohol/polyvinyl acetate copolymers,
polyvinyl alcohol, polyvinyl pyrrolidinones (including those sold
under the tradenames AGRIMER.TM. and GANEX.TM.), cellulose
derivatives such as hydroxymethyl cellulose (including those
commercially available from Dow Chemical Company as METHOCEL.TM.),
and acrylic acid graft copolymers; zwitterionics; and the like; and
mixtures, reaction products, and/or copolymers thereof.
[0064] Additionally or alternatively, the surface active agent may
include, but is not limited to, low molecular weight sodium lauryl
sulfates, calcium dodecyl benzene sulfonates, tristyryl ethoxylated
phosphoric acid or salts, methyl vinyl ether-maleic acid half-ester
(at least partially neutralized), beeswax, water soluble
polyacrylates with at least 10% acrylic acids/salts, or the like,
or a combination thereof.
[0065] Additionally or alternatively, the surface active agent may
include, but is not limited to, alkyl grafted PVP copolymers
commercially available as GANEX.TM. and/or the AGRIMER.TM. AL or WP
series, PVP-vinyl acetate copolymers commercially available as the
AGRIMER.TM. VA series, lignin sulfonate commercially available as
REAX 85A (e.g., with a molecular weight of about 10,000), tristyryl
phenyl ethoxylated phosphoric acid/salt commercially available as
SOPROPHOR.TM. 3 D33, GEROPON.TM. SS 075, calcium dodecylbenzene
sulfonate commercially available as NINATE.TM. 401 A, IGEPAL.TM. CO
630, other oligomeric/polymeric sulfonated surfactants such as
Polyfon H (molecular weight .about.4300, sulfonation index
.about.0.7, salt content .about.4%), Polyfon T (molecular weight
.about.2900, sulfonation index .about.2.0, salt content
.about.8.6%), Polyfon O (molecular weight .about.2400, sulfonation
index .about.1.2, salt content .about.5%), Polyfon F (molecular
weight .about.2900, sulfonation index .about.0.3.3, salt content
.about.12.7%), Reax 88B (molecular weight .about.3100, sulfonation
index .about.2.9, salt content .about.8.6%), Reax 100 M (molecular
weight .about.2000, sulfonation index .about.3.4, salt content
.about.6.5%), and Reax 825 E (molecular weight .about.3700,
sulfonation index .about.3.4, salt content .about.5.4%), and the
like.
[0066] Other notable surface active agents can include nonionic
polyalkylene glycol alkyd compounds prepared by reaction of
polyalkylene glycols and/or polyols with (poly)carboxylic acids or
anhydrides; A-B-A block-type surfactants such as those produced
from the esterification of poly(12-hydroxystearic acid) with
polyalkylene glycols; high molecular weight esters of natural
vegetable oils such as the alkyl esters of oleic acid and
polyesters of polyfunctional alcohols; a high molecular weight
(MW>2000) salt of a naphthalene sulfonic acid formaldehyde
condensate, such as GALORYL.TM. DT 120L available from Nufarm;
MORWET EFW.TM. available from Akzo Nobel; various Agrimer.TM.
dispersants available from International Specialties Inc.; and a
nonionic PEO--PPO--PEO triblock co-polymer surfactant commercially
available as PLURONIC.TM. from BASF.
[0067] Other examples of commercially available surface active
agents include Atlox 4991 and 4913 surfactants (Uniqema), Morwet
D425 surfactant (Witco), Pluronic P105 surfactant (BASF), Iconol
TDA-6 surfactant (BASF), Kraftsperse 25M surfactant (Westvaco),
Nipol 2782 surfactant (Stepan), Soprophor FL surfactant
(Rhone-Poulenc), Empicol LX 28 surfactant (Albright & Wilson),
Pluronic F108 (BASF).
[0068] In one embodiment, exemplary suitable stabilizing components
include polymers or oligomers having a molecular weight from about
250 to about 10.sup.6, preferably from about 400 to about 10.sup.5,
more preferably from about 400 to about 10.sup.4, and can include,
for example, homopolymers or co-polymers described in "Polymer
Handbook," 3rd Edition, edited by J. Brandrup and E. H.
Immergut.
[0069] In another embodiment, exemplary suitable stabilizing
components include polyolefins such as polyallene, polybutadiene,
polyisoprene, poly(substituted butadienes) such as
poly(2-t-butyl-1,3-butadiene), poly(2-chlorobutadiene),
poly(2-chloromethyl butadiene), polyphenylacetylene, polyethylene,
chlorinated polyethylene, polypropylene, polybutene, polyisobutene,
polybutylene oxides, copolymers of polybutylene oxides with
propylene oxide or ethylene oxide, polycyclopentylethylene,
polycyclolhexyiethylene, polyacrylates including polyalkylacrylates
and polyarylacrylates, polymethacrylates including
polyalkylmethacrylates and polyarylmethacrylates, polydisubstituted
esters such as poly(di-n-butylitaconate), poly(amylfumarate),
polyvinylethers such as poly(butoxyethylene) and
poly(benzyloxyethylene), poly(methyl isopropenyl ketone), polyvinyl
chloride, polyvinyl acetate, polyvinyl carboxylate esters such as
polyvinyl propionate, polyvinyl butyrate, polyvinyl caprylate,
polyvinyl laurate, polyvinyl stearate, polyvinyl benzoate,
polystyrene, poly-t-butyl styrene, poly (substituted styrene),
poly(biphenyl ethylene), poly(1,3-cyclohexadiene),
polycyclopentadiene, polyoxypropylene, polyoxytetramethylene,
polycarbonates such as poly(oxycarbonyloxyhexamethylene),
polysiloxanes, in particular, polydimethyl cyclosiloxanes and
organo-soluble substituted polydimethyl siloxanes such as alkyl,
alkoxy, or ester substituted polydimethylsiloxanes, liquid
polysulfides, natural rubber and hydrochlorinated rubber, ethyl-,
butyl- and benzyl-celluloses, cellulose esters such as cellulose
tributyrate, cellulose tricaprylate, and cellulose tristearate,
natural resins such as colophony, copal, and shellac, and the like,
and combinations or copolymers thereof.
[0070] In still another embodiment, exemplary suitable stabilizing
components include co-polymers of styrene, alkyl styrenes,
isoprene, butenes, butadiene, acrylonitrile, alkyl acrylates, alkyl
methacrylates, vinyl chloride, vinylidene chloride, vinyl esters of
lower carboxylic acids, and .alpha.,.beta.-ethylenically
unsaturated carboxylic acids and esters thereof, including
co-polymers containing three or more different monomer species
therein, as well as combinations and copolymers thereof.
[0071] In yet another embodiment, exemplary suitable stabilizing
components include polystyrenes, polybutenes, for example
polyisobutenes, polybutadienes, polypropylene glycol, methyl
oleate, polyalkyl(meth)acrylate e.g. polyisobutylacrylate or
polyoctadecylmethacrylate, polyvinylesters e.g. polyvinylstearate,
polystyrene/ethyl hexylacrylate copolymer, and polyvinylchloride,
polydimethyl cyclosiloxanes, organic soluble substituted
polydimethyl siloxanes such as alkyl, alkoxy or ester substituted
polydimethylsiloxanes, and plybutylene oxides or copolymers of
polybutylene oxides with propylene and/or ethylene oxide. In one
embodiment, the surface active agent can be adsorbed onto the
surface of the biocide particle, e.g., in accordance with U.S. Pat.
No. 5,145,684.
[0072] Another aspect of the invention is a method of preparing a
micronized organic biocide (e.g. penflufen) product comprising the
steps of: 1) providing the organic biocide to a mill, and 2)
milling the material with a milling media having a density greater
than about 2.5 and having a diameter between about 0.01 mm and
about 0.7 mm. The density of the milling media, and especially of
the milling media within the size range 0.1 to 0.5 mm, is
advantageously greater than about 3.5, for example greater than
about 4, preferably greater than about 5.5, for example equal to or
greater than about 6 grams per cubic centimeter. Ceramic milling
media is preferred over metallic milling media.
[0073] In each embodiment, the milling load is preferably about 50%
or higher of the volume of the mill, though loadings between 40%
and 90% are efficient. In each embodiment, advantageously water and
surface active agents or dispersants are added to the product
before or during milling. In each embodiment, the product can be
transported as a stable slurry, as a wettable powder, or as
granules that disintegrate on mixing with water to release the
product.
[0074] Wet milling can be done in a sand grinder charged with for
example partially stabilized zirconia beads with diameter 0.5 mm;
alternately wet milling in a rotary sand grinder with partially
stabilized zirconia beads with diameter 0.5 mm and with stirring at
for example 1000 rpm; or by use of a wet-ball mill, an attritor
(e.g., manufactured by Mitsui Mining Ltd.), a perl mill (e.g.,
manufactured by Ashizawa Ltd.), or the like. Modifications of the
above processes are within the skill of one of ordinary skill in
the art, and such modifications will not be described here.
[0075] A milling process using 0.5 mm high density zirconium
silicate and more preferably 0.5 mm zirconia grinding media
provides further efficient attrition, especially for the removal of
particles greater than about 1 micron in the coarse material of
penflufen. This wet milling process is inexpensive, and all of the
precipitate can be used in the injectable copper-containing
particulate wood treatment. The milling agents can be zirconia,
partially stabilized zirconia, zirconium silicate, and
yttrium/zirconium oxide, for example, recognizing that the more
dense materials give faster particle size attrition. The size and
density of the milling material is believed to be important, even
critical, to obtaining a commercially acceptable process. The
milling agent material having a diameter of 2 mm or greater are
ineffective over hours and days, milling material of diameter of 1
mm is ineffective over times in the prior art, e.g., 10 minutes to
an hour, while milling agent material having a diameter of 0.5 mm
is effective typically after 15 minutes of milling.
[0076] Alternately or additionally, the organic biocide can be
contained in milled injectable solid organic biocide particulates.
Generally, such a small quantity of organic biocides are required
that the d.sub.50 of the organic biocides is advantageously between
about 0.2 to about 0.8 times the d.sub.50 of the copper
compounds.
[0077] The particle size distribution of the particulates in one
embodiment is such that at least about 50% by weight of the
particulates have an average diameter, or mean particle size,
between about 0.02 microns and about 1.0 microns, or preferably at
least about 50% by weight of the particulates have an average
diameter between about 0.05 microns and about 0.5 microns.
[0078] In another embodiments of this invention, the
particulate-based biocidal composition is substantially free of
alkanolamines, e.g., the composition comprises less than 5%
alkanolamines, preferably less than 1.0% alkanolamines, or is
totally free of alkanolamines.
[0079] In preferred embodiments of this invention, the
particulate-based biocidal composition is substantially free of
ammonium compounds (e.g., ammonium hydroxide), e.g., the
composition comprises less than 5% ammonia, preferably less than 1%
ammonia, or is totally free of ammonium compounds, with the proviso
that ammonium compounds whose primary function is as an organic
biocide are excluded.
[0080] In preferred embodiments of this invention, the biocidal
composition is substantially free of organic solvents, e.g., the
slurry comprises less than 1% organic solvents, preferably less
than 0.1% organic solvents, or is totally free of organic
solvents.
[0081] The loading of biocidal composition will depend on a variety
of factors, including the desired copper and/or penflufen loading
in the wood, the porosity of the wood, and the dryness of the wood.
Calculating the amount of copper-based compositions is well within
the skill of one of ordinary skill in the art. Generally, the
desired copper loading into wood is between 0.0025 and about 0.5
pounds copper per cubic foot (pcf) of wood. Generally, the desired
loading of penflufen into wood is between about 4 and about 200
g/m.sup.3, preferably between about 8 and about 80 g/m.sup.3. In
certain embodiments, the current invention comprises a copper
compound and penflufen in a copper:penflufen ratio of between about
1:1 to about 500:1. In another preferred embodiment, the present
composition can further be used in combination with other known
preservative chemicals, including boron based preservatives, such
as boric acid, sodium salt of borates; triazole compounds,
pentachlorophenol, and sodium fluoride. Triazoles of the wood
preservative formulations of the invention include, but are not
limited to epoxiconazole, triadimenol, propiconazole,
prothioconazole, metconazole, cyproconazole, tebuconazole,
flusilazole, paclobutrazol, fluconazole, isavuconazole,
itraconazole, voriconazole, pramiconazole, ravuconazole, and
posaconazole.
[0082] In one embodiment the biocidal composition comprises between
50 and 800 ppm of one or more scale precipitation inhibitors or
corrosion inhibitors, particularly nitrite compounds and
organophosphonates. Nitrite compounds include, not limiting to,
sodium nitrite, calcium nitrite or potassium nitrite. Alternately
or additionally the composition may contain between about 50 and
about 2000 ppm of one or more chelators. Both of these additives
are meant to inhibit precipitation of salts such as calcium
carbonate and the like, where the source of calcium may be from the
water used to make up the slurry. The preferred inhibitors are
hydroxyethylidene diphosphonic acid (HEDP),
diethylenetriamine-pentamethylenephosphonic acid (DTPMP), and/or
2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC). If the
preservative is in a concentrate, the composition should comprise
between 10 mmoles and 100 mmoles/L of HEDP, or between 30 mmoles
and 170 mmoles/L of PBTC or DTPMP. Mixtures of inhibitors are
preferred, as concentrates may have more inhibitor than can readily
be solubilized therein. If the preservative is in a solid form, the
preservative should comprise between about 0.1 to about 1 mole HEDP
per kg of particulates, or between about 0.17 to about 2 mole PBTC
and/or DTPMP per kg of particulates.
[0083] The biocidal composition can contain one or more additives
to aid wetting, for example surfactants. Surfactants may be in
solution, or alternatively may bind to the surface, in which case
they are surface-active agents and may function as stabilizers or
dispersants. Preferred dispersing agents include a surface active
portion that interacts with the copper-containing particle and a
second preferably different portion, which operates to inhibit
irreversible agglomeration of the copper-based particles. For
example, a polyacrylate dispersing agent may include at least one
carboxyl group capable of associating, such as electrostatically,
with a copper-containing particle and a second, hydrophobic portion
that may operate to inhibit the permanent agglomeration of the
copper-containing particles. Exemplary dispersing agents may
include at least one of a surfactant, a polyacrylate, a
polysaccharide, a polyaspartic acid, a polysiloxane, and a
zwitterionic compound. Exemplary compounds useful as dispersing
agents are discussed in the section relating to milling. The
particulate-based biocidal compositions preferably exclude
emulsifiers and surfactants.
[0084] In one embodiment of the invention, the particulate copper
compound may comprise a polymer or polymeric dispersant,
collectively polymer. In this embodiment, the ratio of the weight
of copper present in the particles to polymer present in the
particles may be at least about 100 to 1, for example at least
about 2 to 1, 4 to 1, 5 to 1, 7 to 1, or at least about 10 to 1.
For example, if ratio of the weight of copper present in the
particles to the weight of polymer present in the particles is at
least about 2 to 1, the particles comprise at least about twice as
much copper by weight as polymer. Another aspect of the invention
relates to a preservative useful for wood or wood products, the
preservative preferably comprising a preferably aqueous suspension
of particulate copper compounds and particulate penflufen. If a
polymeric dispersing agent is present in the suspension, the ratio
of the weight of copper present in the copper-based particles of
the suspension to the weight of dispersing agent present in the
suspension may be at least about 1 to 1, for example at least about
5 to 1, 10 to 1, 15 to 1, 20 to 1 or at least about 30 to 1.
[0085] Dispersing agents aid particulate dispersion and to prevent
aggregation of particulates. Sub-micron sized particulates have a
tendency to form much larger aggregates. Aggregates as used herein
are physical combinations of a plurality of similarly-sized
particles, often brought together by van der Waals forces or
electrostatic forces. If aggregates are allowed to form they often
can age into a stable aggregate that cannot be readily broken up by
mechanical agitation, for example by vigorous stirring of a slurry.
Such aggregates may grow to a size where the aggregates are not
readily injectable, or may be of a size to make the aggregates
visible, therefor giving undesired color. In preferred embodiments
of the invention at least 30%, preferably at least 60%, more
preferably at least 90% by weight of the substantially crystalline
particulate copper compounds in a slurry composition are
mono-disbursed, e.g., are not in aggregates. Further, the particles
advantageously do not tend to agglomerate when injected into the
wood. To prevent particulates from agglomerating, the concentrated
slurry or paste may comprise polymers, such as polyvinyl alcohols,
polyvinyl pyrrolidones, polyalkylene glycols and polyacrylates, in
quantities of 0.1 to 20% by weight, based on the weight of the
particulates.
[0086] The biocidal compositions mentioned can be prepared in a
manner known per se, for example by mixing the active compounds
with the liquid carrier, and including dispersants and/or binders
or fixative, and other processing auxiliaries. Particulates can be
provided in a concentrated slurry, in a very concentrated paste, as
dry particulates, as coated dry particulates, as part of a dry
pre-mix, or any combination thereof.
[0087] In one embodiment, the composition of the current invention
is prepared as a concentrate. If the wood treatment is to be
manufactured, stored, or transported in a wetted form, it is
beneficially in a concentrated form to minimize the volume and
expense of handling water. Preferably the concentrated slurry or
paste (for shipping and storing, for example, comprises between 5%
and 80% by weight, for example between about 15% and 40%, of
particulate copper compounds and/or penflufen, with the remainder
of the concentrated slurry or paste beneficially being a fluid
carrier. The concentrated slurry or paste may further comprise
solid particulates that are carriers for one or more organic
biocides, and solid particulates comprising corrosion inhibitors.
The aqueous carrier beneficially comprises one or more additives as
discussed for the slurry, including anti-oxidants, disbursing
agents, other biocidal salts and compounds, chelators, corrosion
inhibitors, e.g., phosphate and/or borate salts, alkali metal
hydroxides and/or carbonates, antifreeze, and the like. The
concentration of these additives will depend in part on the degree
to which the composition is expected to be diluted to make a
commercially useful injectable particulate-based biocidal
composition having the proper copper loading for the types of
wood.
[0088] In one embodiment, the material comprises A) about 30% to
70% by weight of a mixture of a particulate copper compound and
particulate penflufen, e.g., copper hydroxide, for example, about
35% to 65%, such as about 38% to about 61% of a copper compound, in
particulate form; B) about 10% to 35% by weight, such as about 15%
to about 30% of at least one dispersing agent, e.g.,
lignosulfonates or polyacrylates; C) between about 2.5% to 20% by
weight, such as about 5% to 15% of at least one wetting agent, for
example, a surfactant, e.g., Morwet EP available from Barton
Solvents, Inc.; D) between about 5% to about 25% by weight, such as
about 10% to 20% of at least one diluent, for example soluble and
insoluble diluents, such as those used in agricultural products,
e.g., clay, such as an attapulgite clay, or particulate carrier
particles comprising organic biocide; E) between about 0.05% to
7.5% by weight, such as about 0.1% to about 5%, of at least one
antifoam agent; and optionally F) about 2.5% to about 25%,
alternatively less than about 7.5%, such as less than about 5% by
weight, of water.
[0089] Another aspect of the invention relates a method of
preserving wood or a wood product comprising injecting into wood or
dispersing into a wood product one or more of the biocidal
particulate compositions of this invention. The material of this
invention is useful for wood, and also for wood products, e.g.,
wood composites. Exemplary wood products include oriented strand
board, particle board, medium density fiberboard, plywood,
laminated veneer lumber, laminated strand lumber, hardboard and the
like. Preferred methods of preserving wood composites require the
preservative of this invention either be mixed with the wood
material or fibers before bonding, or more preferably injected into
the wood material or fibers, followed by bonding.
[0090] In one embodiment, the wood or wood product has a surface, a
thickness, a width, and a length. Preferably, the wood or wood
product comprises a homogenous distribution of micronized copper
compounds and micronized penflufen. In one embodiment, a volume
number density of the copper-based particles 5 cm from the surface,
and preferably throughout the interior of the wood or wood product,
is at least about 50%, for example, at least about, 60%, 70%, or
75% a volume number density of the copper-based particles 1 cm from
the surface.
[0091] The wood preservative compositions of the invention can be
applied to wood through dipping, brushing, spraying or
vacuum/pressure treatment. Wood or wood products comprising copper
compounds and penflufen in accordance with the present invention
may be prepared by subjecting the present composition into wood
through a vacuum and/or pressure process. In a preferred
embodiment, vacuum and/or pressure techniques are used to
impregnate the wood in accord with this invention including the
standard processes, such as the "Empty Cell" process, the "Modified
Full Cell" process and the "Full Cell" process, and any other
vacuum and/or pressure processes which are well known to those
skilled in the art. In another embodiment, the treating liquid may
be applied by a microwave or radio frequency treating process. In
this process, the wood substrate is first heated using a radio
frequency or microwave energy. The temperature of the heated target
zone can vary from 40.degree. C. to 300.degree. C., and more
preferably 80.degree. C. to 100.degree. C. Immediately after the
heating, a liquid formulation comprising pyrazole and
isothiazolinone is contacted with the substrate. The temperature of
the liquid formulation is below that of the heated target zone at
the time the composition is applied, the difference between the
temperatures of the composition and the heated target zone being
sufficient to reduce pressure in the substrate after the
composition is applied. Various frequencies of radio or microwave
energy may be used. The frequency of the radio frequency or
microwave energy can vary from 0.1 MHz to 100 MHz, preferably
between 10 and 50 MHz, a more preferably from 20 to 40 MHz. Skilled
persons may readily appreciate appropriate wavelengths outside this
range The treating fluid may also be applied to wood by a Microwave
process. The compositions of the present invention can also be used
for supplemental or remedial treatment of wood in service, such as
utility poles and railroad ties. When used as remedial preservative
purpose, the compositions can be in the form of a paste- or
grease-type of formulations, if desired, such that the formulation
has an adhesive nature and is easy to apply to a desired location.
When making a paste or grease type of formulations, 0.5% to about
30% of an inorganic clay thickening agent, or a mixture of such
thickening agents, is often used. The inorganic clay thickening
agents include a fibrous structure type such as attapulgite clay
and sepiolite clay, a non-crystal structure type such as allophone,
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,
montmorillonite, nacrite, 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, kaolinite-montmorillonite. The clay
minerals employed in the compositions of the present invention also
contain exchangeable cations including, but not limited to,
aluminum ions, protons, sodium ions, potassium ions, calcium ions,
magnesium ions, lithium ions, and the like. Among the above
inorganic clay minerals, attapulgite, hectorite, bentonite,
montmorillonite, sauconite, smecnite, stevensite, beidellite,
nontronite, saponite, hectorite, vermiculite, nacrite, and
sepiolite are particularly preferable for the present invention. In
this embodiment, the composition of the present invention can be
applied to the wood surface through external coating treatment.
EXAMPLES
[0092] The following examples are merely indicative of the nature
of the present invention, and should not be construed as limiting
the scope of the invention, nor of the appended claims, in any
manner.
Example 1--Synergism
[0093] The synergism was determined using a modified method as
described by Kull et al. (Applied Microbiology, 1961 (9): 538-541).
The modified method is described as below:
Q.sub.A/Q.sub.a+Q.sub.B/Q.sub.b=SI
Where:
[0094] Q.sub.a=concentration of substance A alone which controls a
particular decay fungus Q.sub.b=concentration of substance B alone
which controls a particular decay fungus Q.sub.A=concentration of
substance A in the concentration of the A and B mixture at which
controls a particular decay fungus Q.sub.B=concentration of
substance B in the concentration of the A and B mixture at which
controls a particular decay fungus SI=1 means additivity SI>1
means antagonism SI<1 means synergism
Example 2--Synergistic Activity of a Combination of Copper
Fungicide and Penflufen Against Various Wood Decay Brown Rot
Fungi
[0095] Wood cubes measuring 19 mm.times.19 mm.times.19 mm were
prepared from southern pine sapwood. One set of wood cubes were
pressured treated with serial treating solutions containing
penflufen fungicide. A second set of wood cubes were pressure
treated with treating solutions containing the copper fungicide. A
third set of wood cubes were pressure treated with treating
solutions containing a mixture of the copper and penflufen. The
treated wood samples were exposed to various fungi to conduct a
laboratory decay resistance test following protocols as described
in American Wood Protection Association Standard E10-2015. Before
and after exposure to fungi, the wood samples were weighed to
determine the weight percent loss. No weight loss means complete
control of the fungal attack. The results are reported in Table
1.
TABLE-US-00001 TABLE 1 Copper Retention in Cu to Penflufen Brown
Rot Fungi Wood as Cu in kg/m.sup.3 Ratio SI Gloeophyllum trabeum
0.91 228 to 1 0.37 Fibroporia radiculosa 0.91 23 to 1 0.79 Postia
placenta 0.91 114 to 1 0.95 Coniophora Postia 0.91 228 to 1 0.79
puteana
Example 3--Wood Stakes Treated with Amine Copper and Penflufen
Field Efficacy Testing
[0096] Wood stakes measuring 19 mm.times.19 mm.times.450 mm were
prepared from southern pine sapwood. The wood stakes were treated
with treating solutions containing a copper ethanolamine solution
and a penflufen emulsion at different ratios varying from
copper:penflufen of 5:1 to 200:1. The treated wood stakes were
installed in field testing plots such as Gainesville, Fla. and
Maunawili, Hi., and both testing locations have been well
established to have severe decay hazard. The field stakes were
inspected for efficacy against decay fungi and termite annually,
and the test were conducted following protocols as described in
American Wood Protection Association Standard E7. The annual
inspection results from both filed locations indicated that wood
stakes treated with copper and penflufen are resistant to decay and
termite attack.
Example 4--Wood Stakes Treated with Micronized Copper and Penflufen
Field Efficacy Testing
[0097] Wood stakes measuring 19 mm.times.19 mm.times.450 mm were
prepared from southern pine sapwood. The wood stakes were treated
with treating solutions containing micronized copper fungicide and
a penflufen at different ratios varying from copper:penflufen of
5:1 to 200:1. The treated wood stakes were installed in field
testing plots such as Gainesville, Fla. and Maunawili, Hi., and
both testing locations have been well established to have severe
decay hazard. The field stakes were inspected for efficacy against
decay fungi and termite annually, and the test were conducted
following protocols as described in American Wood Protection
Association Standard E7. The annual inspection results from both
filed locations indicated that wood stakes treated with copper and
penflufen are resistant to decay and termite attack.
Example 5--Wood Stakes Treated with Micronized Penflufen Field
Efficacy Testing
[0098] Southern pine wood samples were treated with treating
solutions containing a micronized penflufen at different loadings
in wood varying from 10 to 250 grams per cubic meter. The treated
wood stakes were installed in field testing plots such as
Gainesville, Fla. and Maunawili, Hi., and both testing locations
have been well established to have severe decay hazard. The field
stakes were inspected for efficacy against decay fungi and termite
annually, and the test were conducted following protocols as
described in American Wood Protection Association Standard E16. The
annual inspection results from both filed locations indicated that
wood stakes treated with micronized penflufen are resistant to
decay and termite attack.
Example 6--Preparation of Micronized Penflufen
[0099] Penflufen was mixed with a dispersant in water medium. The
mixture slurry was mixed for about 10 minutes, and then transferred
to a ball mill containing zirconia grinding media according to the
present invention. The slurry was ground for about 2 hours and
stable micronized penflufen dispersion was obtained. The particle
size of the penflufen dispersion was monitored by measuring its
particle size. The results are reported in Table 2.
TABLE-US-00002 TABLE 2 Particle Size Stability of Penflufen
Dispersion at Different Temperatures 4.degree. C. 24.degree. C.
32.degree. C. Test d.sub.50, D.sub.95, Mean, d.sub.50, D.sub.95,
Mean, d.sub.50, D.sub.95, Mean, Duration .mu.m .mu.m .mu.m .mu.m
.mu.m .mu.m .mu.m .mu.m .mu.m Initial 0.298 0.490 0.311 0.298 0.490
0.311 0.298 0.490 0.311 1 Month 0.310 0.495 0.319 0.315 0.497 0.323
0.331 0.505 0.341 4 0.312 0.496 0.321 0.317 0.498 0.325 0.323 0.500
0.331 Months 6 0.309 0.494 0.316 0.307 0.494 0.315 0.336 0.506
0.343 months
Example 7--Preparation of the Mixture of Micronized Copper and
Micronized Penflufen
[0100] Micronized copper was prepared by milling a slurry of basic
copper carbonate and micronized penflufen was prepared by milling
penflufen solid. The final micronized copper and micronized
penflufen were mixed together at various ratios, and the particle
size of the final mixture was monitored. The results are reported
in Tables 3-5. The level of copper and penflufen in the mixture was
also monitored by chemically analyzing the copper content and
penflufen content, and the result is given in Table 6.
TABLE-US-00003 TABLE 3 Particle Size Stability of Mixture of
Penflufen in Dispersed BCC (Cu:Penflufen = 25:1) at Different
Temperatures 4.degree. C. 24.degree. C. 38.degree. C. Test
d.sub.50, D.sub.95, Mean, d.sub.50, D.sub.95, Mean, d.sub.50,
D.sub.95, Mean, Duration .mu.m .mu.m .mu.m .mu.m .mu.m .mu.m .mu.m
.mu.m .mu.m Initial 0.365 0.532 0.369 0.365 0.532 0.369 0.365 0.532
0.369 3 weeks 0.365 0.500 0.358 0.362 0.506 0.365 0.369 0.521 0.373
6 weeks 0.339 0.498 0.344 0.361 0.522 0.365 -- -- -- 6 0.353 0.505
0.357 0.357 0.513 0.361 0.356 0.510 0.360 months
TABLE-US-00004 TABLE 4 Particle Size Stability of Penflufen in
Dispersed BCC (Cu:Penflufen = 50:1) at Different Temperatures.
4.degree. C. 24.degree. C. 38.degree. C. Test d.sub.50, D.sub.95,
Mean, d.sub.50, D.sub.95, Mean, d.sub.50, D.sub.95, Mean, Duration
.mu.m .mu.m .mu.m .mu.m .mu.m .mu.m .mu.m .mu.m .mu.m Initial 0.365
0.531 0.370 0.365 0.531 0.370 0.365 0.531 0.370 3 weeks 0.349 0.493
0.351 0.366 0.508 0.368 0.369 0.527 0.373 6 weeks 0.334 0.491 0.338
0.366 0.529 0.370 -- -- -- 6 0.337 0.493 0.341 0.360 0.521 0.364
0.361 0.523 0.366 months
TABLE-US-00005 TABLE 5 Particle Size Stability of Mixture of
Penflufen in Dispersed BCC (Cu:Penflufen = 100:1) at Different
Temperatures. 4.degree. C. 24.degree. C. 38.degree. C. Test
d.sub.50, D.sub.95, Mean, d.sub.50, D.sub.95, Mean, d.sub.50,
D.sub.95, Mean, Duration .mu.m .mu.m .mu.m .mu.m .mu.m .mu.m .mu.m
.mu.m .mu.m Initial 0.365 0.530 0.370 0.365 0.530 0.370 0.365 0.530
0.370 3 weeks 0.355 0.499 0.357 0.362 0.508 0.365 0.372 0.525 0.375
6 weeks 0.352 0.505 0.356 0.363 0.527 0.368 -- -- -- 6 0.355 0.507
0.359 0.358 0.516 0.363 0.358 0.515 0.362 months
TABLE-US-00006 TABLE 6 Stability of Active % Penflufen in Dispersed
BCC Solution at Different Temperatures. Cu:Penflufen = Cu:Penflufen
= Cu:Penflufen = 25:1 50:1 100:1 Test Duration 24.degree. C.
38.degree. C. 24.degree. C. 38.degree. C. 24.degree. C. 38.degree.
C. Initial 1.22 1.22 0.66 0.66 0.33 0.33 1 week 1.24 1.21 0.66 0.66
0.33 0.33 2 weeks 1.21 1.22 0.66 0.67 0.33 0.33 3 weeks 1.23 1.22
0.67 0.66 0.33 0.32 4 weeks 1.23 1.23 0.67 0.67 0.33 0.33 8 weeks
1.24 1.21 0.68 0.66 0.34 0.33 12 weeks 1.22 1.42 0.65 0.64 0.33
0.31 16 weeks 1.21 1.09 0.67 0.65 0.33 0.31 24 weeks 1.34 1.20 0.69
0.66 0.34 0.32 48 weeks 1.22 1.24 0.68 0.67 0.34 0.33
Example 8--Bio-Efficacy of Dispersed Penflufen Against Wood Decay
Fungi
[0101] Wood cubes measuring 19 mm.times.19 mm.times.19 mm were
prepared from southern pine sapwood. The wood cubes were pressure
treated with treating solutions containing micronized penflufen.
The treated wood samples were exposed to various fungi to conduct a
laboratory decay resistance test following protocols as described
in American Wood Protection Association Standard E10-2015. Before
and after exposure to fungi, the wood samples were weighed to
determine the weight percent loss. The test results are summarized
in Table 7.
TABLE-US-00007 TABLE 7 Mean Percent Weigh Loss of Treated Wood
Cubes at Different Penflufen Retention. Decay Fungi Penflufen
Coniophora Gloeophyllum Fibroporia Postia Retention, g/m.sup.3
puteana trabeum radiculosa placenta 8 1.4 3.1 12.0 3.5 12 1.6 2.9
10.4 1.9 16 1.6 3.6 8.2 2.1 24 1.5 3.0 8.2 1.2 32 1.1 3.5 5.4 1.2
48 1.4 3.0 5.7 1.1 64 2.0 1.6 4.4 1.1 80 1.3 2.0 3.0 1.3 0
(Untreated 25.3 41.7 49.1 47.5 SP)
Example 9--Preparation of Wood Preservative Treating Solution
Comprising Micronized Copper and Penflufen Actives
[0102] A series of wood preservative treating solutions were
prepared by mixing a micronized copper concentrate and a penflufen
concentrate with water. Alternatively, the wood preservative
treating solutions can be prepared by diluting micronized
copper+penflufen concentrate with water. Other additives, such as
mold inhibitors, water repellent, and/or pigments can be added to
the treating solutions as well. The penflufen can be prepared
either as an emulsion concentrate (EC) or a suspension/dispersion
concentrate (SC) or combination of suspoemulsion concentrate (SEC),
or a soluble solution concentrate. After preparation of the
treating solutions, the concentration of both copper and penflufen
actives were monitored and measured over a 16-week period under
ambient conditions. The results as shown in Table 8 indicate that
there are minimal to negligible changes in the active concentration
of copper and penflufen. The results further indicate that the
combination of copper/penflufen composition disclosed in the
current application is a viable formulation for treating wood.
TABLE-US-00008 TABLE 8 The Active Concentration of Copper and
Penflufen during Storage under Ambient Conditions. 0 Weeks 2 Weeks
4 Weeks 8 Weeks Penflufen Penflufen Penflufen Penflufen 16 Weeks Cu
(%) (%) Cu (%) (%) Cu (%) (%) Cu (%) (%) Cu (%) Penflufen (%)
Solution #1 0.198 0.0069 0.200 0.0066 0.200 0.0065 0.200 0.0071
0.198 0.0066 Solution #2 0.497 0.0177 0.499 0.0174 0.500 0.0174
0.505 0.0180 0.501 0.0173 Solution #3 0.193 0.0037 0.194 0.0035
0.194 0.0035 0.195 0.0034 0.195 0.0035 Solution #4 0.495 0.0097
0.500 0.0094 0.499 0.0093 0.497 0.0093 0.497 0.0094 Solution #5
0.195 0.0017 0.196 0.0016 0.196 0.0015 0.197 0.0014 0.196 0.0015
Solution #6 0.491 0.0046 0.496 0.0043 0.502 0.0043 0.499 0.0045
0.502 0.0045
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