Note: Descriptions are shown in the official language in which they were submitted.
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INTRODUCTION
This invention relates to fungicides and more particularly
to cuprammonia low carboxylate compositions which are made sub-
stantially noncorrosive in a liquid concentrate form and which,
when diluted with water, hydrolyze to bactericidally and fungi-
cidally active materials. The hydrolized product formed there-
from, when applied to the locus of a fungus or bacteria to be
controlled, effectively controls said fungus or bacteria.
BACKGROUND OF THE INVENTION
It is well-known that fungi are a large group of nongreen
plants that receive their energy and raw materials through para-
sitic habits. Fungi are dependent upon the organic food made by
photosynthesizing green plants. They represent a constant and
ever present threat to many agricultural crops ranging from tropi-
lS caland semi-tropical vegetation to temperate climate crops. The
control of fungi has been achieved through the use of a hetero-
geneous group of chemicals termed "fungicides~ that mitigate, in-
hibit or destroy fungi. Such fungicides have been applied by
spray or dust applications of protective or eradicative amounts
of the material to the locus of the fungi to be controlled.
The bacteria, also, form a well-known class of microscopic plants
having round, rod-like, spiral or filamentous single-celled or
non-cellular bodies which are often aggregated into colonies or
motile by means of flagella. Bacteria live in soil, water, or
organic matter, in the bodies of plants and animals, and are
autotrophic, saprophytic, or parasitic in nutrition. Bacteria
can be either helpful or harmful to man~ind and are often used by
man to his advantage. It is often desirable and necessary to
control bacteria to prevent damage to organic matter. As such,
bactericides perform a valuable function in the control or eradi-
108;~7~3
cation of unwanted bacteria.
The compositions of this invention are particularly valuableas bactericides when applied to the locus of bacteria to be con-
trolled in an effective amount. The method and amount of compo-
sition applied to effect bacteri~i~l control is similar to thefungicidal method and amount. Consequently, the presented in-
vention will be described more particularily with respect to the
fungicidal use because such use has been more extensively investi-
gated and is the preferred use. This, however, is not to in any
manner limit the scope of the present invention, but rather is a
manner of more clearly setting forth the preferred embodiments of
the present invention.
Prior to about 1939, inorganic sulfur and copper compounds
were used almost exclusively as sprays and dust fungicides. Cop-
per and mercury compounds were also used as applications in seedtreatments. As early as 1882, copper sprays were introduced as
a Bordeaux mixture for the control of do~my mildew on grapes. The
Bordeaux mixture consisted of a light blue gelatinous precipitate
suspended in water and formed by reacting 4 parts of copper sulfate
to 4 parts of hydrated lime (calcium hydroxide) in 50 gallons of
water. Various variations in the composition of the resulting
mixture have been made by changing the ratio of the components.
While copper co~pounds have been known for their ability to
control fungi, soluble copper compounds are known to be extremely
toxic to vegetation. Consequently, the copper materials applied
must be relatively non-toxic to the plants while being effective
fungicides. As such, it is necessary, in order to have an effec-
tive fungicide, to have an insoluble copper material in finely
divided form which can be effectively applied to vegetation in a
3~ manner whereby it will adhere to the vegetation while remaining
non-toxic to the vegetation to which it is applied. The finer
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~08~7Z3
the copper compound, the more surface area it can cover and there-
fore, in general, the more effective it will be per unit weight.
It is well-known that various materials, including copper
compounds, can be milled to extremely fine particle size such that
the surface area of the particle becomes extremely large. With
finely milled material, theoretically such material is able to
cover massive surface areas with relatively small amounts of copper
compound. As a practical matter, it is extremely difficult to
disperse and/or redisperse such finely milled co~er materials be-
L0 cause of the tendency of fine particles to agglomerate such thatthe finely divided particles are not fully dispersed but rather
accumulate as larger particles, thus greatly reducing the effec-
tiveness and surface area of the material.
It has been discovered that an effective way of producing
L5 the required finely divided dispersant of copper values is to pre- -
cipitate the copper values in situ. Under certain desirable con-
ditions, copper can be made to precipitate in the desired finely
divided state. However, it is also well-known that the more de-
sirable copper solutions are corrosive, particularly visa brass
For example, copper chloride is used as an etchant. Cuprammonia
is known to be a much more powerful corrosive than either copper
or ammonium ions individually. With the corrosive nature of
copper solutions, it is particularly parenthetical that brass is
the most widely used material for fungicidal spraying equipment,
particularly the pumps, valves and nozzles used in such equipment.
This corrosiveness is well docum~by Rumford, Chemical Engineer-
ing Materials, 1st American Edition, pp. 194.
If the ammonia in a spray-type cuprammonia fungicide solution
is bound by simply changing the pH, then as the pH of 7 is approached
on the alkaline side, the copper q~antitatively turns to an insolu-
ble form ~hich settles to the bottom of the storage containers. On
---- 10827Z3
the other hand, if the copper is prevented from precipitating
with chelating agents such as EDTA (ethylene diamino tetra ~ :
acetate), it will not deposit the active adherent form of
copper required to protect the vegetation.
In accordance with the invention, there is provided
a substantially noncorrosive concentrate solution which is
hydrolyzable to a fungicidal composition comprising an aqueous
cuprammonium lower carboxylate complex of coppèr lower carboxy-
late and ammonium lower carboxylate in weight proportions of
about 13 parts of copper lower carboxylate as measured as the
dihydrate to about 2 parts of ammonium lower carboxylate and ~
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~' .
. ~ . .
108~7~3
. .
about 10 parts of 29 percent aqueous ammonia, said solution
being at a pH in the range of about 7.1 to 7.4, said concentrate
being diluted with water in an amount not exceeding about 50
parts by weight.
The low carboxylate is selected from the group consisting
of formate, acetate and propionate, with acetate being the most
preferred carboxylate.
The present composition effectively eliminates , suppresses,
retards, reduces, or otherwise controls the activity of a wide
variety of fungi and bacteria.
The composition can be applied as a dilute spray or concen-
trate spray either in ground applications or aerial applications.
The composition can be used alone or in conjunction with insecti-
cides, miticides, or other fungicides as well as extenders, sur-
factants, spreaders, stickers, or oils including colloidal and
non-ionic materials.
DETAILS OF TI~E INVENTION
The composition of the present invention is produced by react-
ing specific amounts of copper, ammonium low carboxylate, and
aqueous ~29%) ammonia so as to produce a complex having a pH in
the range of about 7.1 to about 7.4 and a copper content of about
8.0 to approximately 8.20 percent~ In place of acetate, the cor-
responding formate or propionate can be substituted in correspond-
ing proportions to produce a complex of comparable copper content
and pH range. Because the most preferred carboxylate is acetate,
the invention will be more fully described with reference to ace-
tate, while it should be recognized that formate and/or propion-
ate can be substituted for the acetate in similar proportions to
proauce correspondingly good results. Consequently, because the ~ ;
preferred mode of invention iswith acetate, the description will
be described hereinaft~er more particularly with respect to the
acetate embodiment.
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The composition of the present invention can be produced by
several methods. One method is the utilization of metallic cop-
per, ammonium hydroxide, or anhydrous ammonia, acetic acid and
water reacted at a basic pH at elevated temperatures with the
addition of oxygen or air. The complex can be produced by
reacting the prerequisite amounts of copper, ammonia and acetic
acid below reflux at a pH in excess of 7 and preferably 8 or
more, subsequently adjusting the pH to the desired range of 7.1
to 7.4 by raising temperature to reflux and evaporating ammonia
from the reaction solution. Alternatively, rather than using
metallic copper, copper oxide can be substituted.
This latter method is not as suitable for the production of
the corresponding propionate complex because copper oxide tends
to form upon refluxing of such complex. The noted method, how-
ever, is quite acceptable and desirable for the production ofeither the corresponding formate or acetate complex.
Alternatively, a particularly desirable method of forming
the complex is by direct reaction of copper acetate, ammonium
acetate in aqueous ammonia. Typically, 132 parts of copper ace-
tate in the dehydrate form are reacted in a solution of 220 partswater and 100 parts of aqueous ammonia (29~ NH3) and 20 parts of
ammonium acetate. The resulting mixture is reacted at room
temperature up to the reflux temperature to produce a cuprammonia
acetate complex having a pH in the range of 7.1 to 7.4 and a
copper content of about 8.0 to 8.2 percent.
The amount of water used in the concentrate solution must
be within certain preferred limits because an excess of water
will result in the hydrolysis of the copper values to precipi-
tate them from solution as described herein and to thereby form
the fungicidally active material. Consequently, the amount of
water used will be that which is sufficient to form the concen-
trate solution complex but insufficient to hydrolysis the
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~08'~7'~3
complex. The most preferred amount of waters is 22 parts by
weight based on 13 parts of copper carboxylate dihydrate, 2
parts of ammonium carboxylate and 10 parts of 29~ aqueous
ammonia. This amount of water can be varied,depending on the
carboxylate,from as little as about 10 parts to up to about
50 parts by weight, which represents a solution containing
from about 40% water to about 75% water with about 55% water
being the most preferred. Larger percentages of water will
result in hydrolysis as described herein.
The resulting preferred complex has a specific gravity
within the range of 1.155 to 1.166, the variability being
dictated by the exact amount of copper values and the inerts
which might be present. Greater or lesser amounts of water
will also change the specific gravity.
It should be noted that acetic acid or acetates in conjunc-
tion with copper are not ordinarily considered solublizing (che-
lating) agents for copper. To the contrary, the presence of
acetic acid or acetates is considered to lower the solubility
of copper salts. Illustratively, the nitrates, chlorides, and
sulfates of copper all have solubilities several times that of
copper acetate. In addition to making copper soluble at pH con-
ditions where it would normally be precipitated, the reaction
product retains the desired precipitate characteristics found in
cuprammonia complexes. This is accomplished by depositing a
hydroxide form of copper rather than a basic acetate when the
copper acetate solution is diluted.
Attempts to structurally determine the reaction products of
the present invention by the usual analytic chemical techniques
of functional group analysis, degradative structural analysis
and the separation and identification of residues has been in-
conclusive. It is believedthat the reaction product is a cupra-
mmonia acetate complex having the mono-molecular form Cu(NH3)2
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~0~'~7;~3
(O-CO.C~3)2. ~ile applicant does not wish to be bound by any
particular theory, it is believed that the composition is best
identified by the proportions of copper, ammonia,acetate and pH
of the solution.
The complex of the present invention is considered to be a
concentrate which retains its clear solution characteristics.
For fungicidal or bactericidal used, ~he complex of the
present invention is hydrolized by diluting the complex with water
in the amount of about 3 to 200 parts of water per part of com-
plex solution. The water dilution hydrolizes the complex, thereby
forming a copper hydroxide precipitate which has the particularly
desirab~e property of forming a finely dispersed flocculent material
which remains suspended in solution with a very slow settling
tendency. This flocculent precipitate of finely divided copper
values is readily applied to the locus of fungi or bacteria to be
controlled such as by spraying the area to be treated. The applied
hydrolized precipitate forms a tough gelatinous film on vegetation,
plants,leaves, etc. Once this film dries, it adheres tenaciously
to the substrate to ~hibh it was applied and is not readily re-
moved by the action of rain, dew, or other atmospheric moisture.
The gelatinous nature of this hydrolized complex makes itparticularly useful in conjunction with other chemicals which
otherwise do not readily lend themselves to durable applications
to vegetation. For instance, materials of low water solubility
such as sulfur and lime can be made to adhere to vegetation in dis-
persed form by the binding effect of the present material.
The composition of the present invention can additionally be
mixed with various other fungicidal, herhicidal, insecticidal,
bactericidal~ or inert materials which are desirably applied along
with the present material. For instance, finely divided sulfur,
lime, fillers, or inerts can be mixed with the present composition.
~urther, various other fungicides form compatible mixtures and/or
synergists with the present composition.
_g_
108;~723
It is frequently desirable to add insecticides, miticides,
or herbicides in the same spraying application. Such composi-
tions, for the most part, are compatible with the present com-
position. Typical examples of such materials which can be mixed
and applied with the present invention include chlorobenzilates,
and composition sold under the trade names of Benlate 50W*;
Bravo W-75*; Captan 50-W*; Cygon 267*; Diazinon*; Difolatan 4
Flowable*; DiSyston 4EC*; Dithane M-45*; Dursban Insecticide*;
Ethion 4E*; Guthion*; Kelthane MF*; Lannate-L*; Malathion EC*;
Manzate 200*; Methyl & Ethyl Parathion EC*; Phosdrin 4 ED*;
Plictran Miticide*; Sevimol 4*; Sevin 80 WP*; Systox*; Thiodan*;
Topsin-M*; Toxaphene*; Trithion 4E*; and many others.
Most non-ionic and/or colloidal surfactants, spreaders,
and stickers can also be used with the present composition.
Such materials are often useful in aiding the dispersal of other-
wise difficult to disperse additives which might be desirably
mixed with the present invention in simultaneous applications.
The rate of application depends upon the particular plant
being treated and the fungus against which protection is desired.
The concentrate is preferably diluted in the amount of 3 to 100
parts of water per part of complex. The dilution product is ap-
plied in the amount of 2 to about 800 gallons of water per acre.
Typical of the fungus which can be controlled by the
present invention when applied to the locus of the fungus to be
controlled include almond brown rot, apricot brown rot, blossom
rot, beans bacterial blight and halo blight, carrots early
and late blight, celery early and late blight, citrus fruits
melanose and greasy spot; cantaloupes, melons, cucumbers,
squash, etc. powdery mildew, scab, alternaria and angular leaf
spots, coffee beans, grapes anthracnose, peanuts cercospora
leaf spot, peaches and nectarines
*Trade Mark
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108~7'~3
blossom rot, peppers cercospora leaf spot and bacteria spot, po-
tatoes early and late blight, strawberries leaf spot and scorch,
sugar heets cercospora leaf spot, tomatoes early and late blight
and bacterial spot, walnut blight and numerous other fungus and
other fungus and bacteria.
The invention will be more readily understood by reference
to the following example which illustrates certain preferred em-
bodiements of the present invention and in no way are to be taken
as limiting the scope of the present invention. Unless other-
wise noted, all parts and percentages are by weight.Example 1
In this experiment,cuprammonia acetate and cuprammonia car-
bonate were diluted and the amount of copper precipitate was
measured. This illustrates the deposition control property of
the composition according to this invention. At the end of this
time period, the copper oontent in terms of the grams oo~per per liter
left in solution and the per cent copper precipitated were meas-
ured for each dilution ratio.
Cuprammonia Acetate Complex 8% Cu
20 Dilution 3:1 6:1 30:160:1 100:1
Gr Cu/Liter 16.15 6.78 0.400.15 0.038
left in sol.
~ Cu 30.39 48.91 86.6790.14 95.86
precipitated
25 Copper Ammonia Carbonate 8% Cu
Dilution 3:1 6:1 30:1 60:1 100:1
Gr Cu/Liter23.76 13.10 2.9761.296 0.54
; left in sol.
Cu 1.02 4.59 4.0017.45 43.16
30 precipitated
` 10~27Z3
Example 2
I~JO identical brass surfaces were exposed at least 48 hours
in respective solutions of cuprammonia acetate and cuprammonia
carbonate. The object of this test was to determine the difference,
if any, in the corrosion rates of the brass as a function of ex-
posure to these solutions.
It was observed that the corrosion rate of brass exposed to
the acetate in terms of weight loss after 48 hours, was 0.582
grams or an absolute rate of 0.0102 inches per month. In con-
10 trast, the carbonate caused a brass weight loss of 13.61 gramsat an absolute rate of 0.2417 inches per month.
Example 3
The composition of the present invention was produced by
reacting at atmospheric`temperature pressure about 13 parts of
15 copper acetate dihydrate with about 2 parts of ammonium acetate
in a solution of 10 parts of 29 percent aqueous ammonia and about
22 parts of water. On mixing and reacting, a slight exothermic
reaction was noted. The pH of the solution was adjusted to be
within the range of 7.1 to 7.4 and the copper content in the range
20 of 8.0 to 8.2 percent.
Example~ 4
In the same manner, copper ammonium formate was reacted at
atmospheric temperature and pressure using the same molar propor- -
tions as Example 3, but substituting ammonium formate for the
25 ammonium acetate and copper formate for copper acetate. On
reacting, a slight exothermic reaction was also noted. The result-
ing cuprammonium formate complex was adjusted to a pH between 7.1
and 7.4 in a copper ccntent of 8.0 to 8.2 percent.
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11)8A~7Z3
Example 5
In the manner of Example 3, copper ammonium propionate com-
plex was produced by reacting copper propionate at room tempera-
ture and pressure with ammonium propionate in a~ueous solution
with ammonia in the molar proportions of Example 3. A slight
exothermic reaction was noted on mixing and reacting. The result-
ing cuprammonium propionate complex was adjusted to a pH between
7.1 and 7.4 in a copper content of 8.0 to 8.2.
Example 6
Cuprammonium acetate complex of the present invention was
prepared by reacting metallic copper and cxygen or air in a solution of
ammonium hydroxide and acetic acid. An aqueous solution of about
equal molar proportions of acetic acid and ammonium hydroxide
was prepared and the pH of the solution was adjusted to between
8 and 12 by the addition of excess ammonium hydroxide. Finely
divided copper was then added to equal about 8.0 to 8.2 percent
by weight.
Oxygen (air) was bubbled through the solution. An exo-
thermic reaction was noted. The pH of the complex solution was
then adjusted to between 7.1 and 7.4 by evaporating ammonia
from the complex solution.
In the same manner, anhydrous ammonia can be substituted
for all or part of the ammonium hydroxide and copper oxide of
25 metallic copper and air i,n place of oxygen with correspondingly
good results.
Example 7
The composition of the present invention as described more
particularly in Example 3 was tested for fungicidal and bacteri-
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108'~7Z3
cidal activitity by treating various crops with the complex
diluted with water as set forth in Table I.
Table I
% Foliar ~ Foliar
Fw~s to be Amount of Infection of Infection of Increased
Plant Controlled Application TreatedNbntre~ted Yield
Head ~ettuoe D~ny Mildew 1 pt/A in 9.0 28.7
25 gal H2O
Cabbage Downy Mildew 1 pt/A in6.5 27.6
Cauliflower 25 gal H20 7.7 29.1
Cabbage Altervaria 1 pt/A in 18.8 37.8
Blight 25 gal H2O
Caulifl~er Altervaria 1 pt/A in 11.3 28.9
Blight 25 gal H20
15 Soybean Fungus - 2/3 gal/A
Varicus in 50 gal H20 - - 8%
Onions Rot Control 3.3 gt/ 25.0 61.5
of Dried 100 gal H2O
onions as a dip
20 Pecan Scab 3 qts/ - - 48%
100 gal
The above examples illustrate but a few of the fungi controlled
by the composition of the present invention when applied to the locus
of the fungus to be controlled. The test results indicate that sub-
stantial benefits are obtained in reducing the fungicidal activity
as measured by reduction in infected foilage or increased yield as
compared to the control which was untreated plants.
While the invention has been described with reference to
particular preferred embodiments thereof, it will be understood
by those skilled in the art that various changes in form and
detail may be made therein without departing from the spirit or
scope of the invention. Consequently, the invention is not to be
limited other than as set forth in the appended claims.
.
