This invention relates lớn an improved copper fungicide và the method of producing the samne. So-called Bordeaux mixtures, which are mixtures made from copper sulphate & lime, have been-used extensively as fungicides but are subject lớn certain disadvantages & objections. One underlying...


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This invention relates to an improved copper fungicide and the method of producing the samne.

So-called Bordeaux mixtures, which are mixtures made from copper sulphate và lime, have been-used extensively as fungicides but are subject khổng lồ certain disadvantages and objections.

One underlying disadvantage of these Bordeaux mixtures is that they are chemically unstable.

It is well known that chemical changes continue khổng lồ occur if a Bordeaux solution is allowed lớn stand. The result is that various complex copper compounds are formed. These compounds are dangerous to lớn plant life và render the compound not only dangerous but unreliable and uncertain. It is probable that physical changes also occur & that these changes increase the unreliable and uncertain characteristics of the compounds.

While it is usually inferred that these Bordeaux mixtures are formed in accordance with the simple equation: CuSO4+Ca(OH) 2=Cu(OH) 2+CaSO4 25 it is my belief that the cause of their instability is the fact that the reaction indicated is not truly & completely realized; that an appreciable amount of copper sulphate, which is definitely acid, is incompletedly reacted, forming 30 a basic copper sulphate which is also acid in character và is unstable và variable in composition.

It is usually recommended that freshly made Bordeaux mixtures be used immediately. But even this immediate use by no means solves the problem. Even freshly made mixtures are uncertain, dangerous & unreliable in their action.

I have definitely proved that such freshly made mixtures, prepared cold in the usual manner, are incompletely và variably reacted, that the component parts consequently size little more than an actual "mixture" & that varying amounts of basic copper sulphate, of acid character, are always present.

Bordeaux mixtures are also prepared in dry khung for subsequent use. This may, for convenience, be termed the commercial form. These commercial mixtures are subject khổng lồ much the same objections. They are unstable & their varying chemical & physical composition renders them uncertain, dangerous and unreliable.

It is my belief that the failure of a true và complete reaction between the copper sulphate & calcium hydroxide results in the formation of undesirable copper compounds, which continue to lớn react during the drying process or subsequently during storage.

All these forms of Bordeaux mixtures-freshly made, old và commercial-have additional common disadvantages. In an attempt to protect the plants it is customary to lớn use a large excess of lime. But notwithstanding this excess there is no assurance of the absence of acid copper compounds and the lime serves primarily as a mere buffer. Even when large excesses of lime are present the use of these mixtures is restricted to plants of the hardier types. Moreover, the excess lime added to protect the plants from the copper compounds also serves lớn protect the fungi to lớn a considerable extent.

A further objection lớn these Bordeaux mixtures is that they cannot be mixed with insecticides of the organic or sulphur types. Because of their instability và the presence of acid copper compounds which require the use of an excess of lime, organic insecticides such, for example, as rotenone & pyrethrum are decomposed upon an attempted mixture. For the same reason, a mixture with sulphur insecticides resuits in the formation of copper sulphide or other undesirable copper compounds.

This inability to lớn mix with certain insecticides và fungicides is often a serious disadvantage khổng lồ the grower because of the time and expense involved in separate applications.

Further, Bordeaux mixtures cannot be mixed with many spreaders and stickers, such mixtures being limited to products that are compatible with lime.

Certain so-called basic .copper sulphates have also been used as fungicides but these are subject to lớn much the same objections & disadvantages as the Bordeaux mixtures previously used.

It is an object of the present invention to lớn provide a copper fungicide that avoids the objectionable & disadvantageous features of Bordeaux mixtures and bas copper sulphate mixtures." More particularly, it is an object of the invention lớn provide a copper fungicide that can be safely used on even the more delicate types bf plants; one that can be produced in powder size for subsequent use in that khung or in liquid orm, and that is safe & reliable regardless of lapse of time; one that does not depend for safety on dilution by lime và hence is highly efficient; and one that can be mixed with other desired insecticides or fungicides & thus attain the advantage of a single application.

It is still a further object of the invention to provide such a fungicide in a simple & economical manner.

I have discovered that improved fungicidal protection with practical safety can be attained by the use of a neutral & stable copper compound.

While various compounds of such characteristics may be used, I have found that a satisfactory compound comprises essentially copper hydroxide in the absence of any substantial amount of any acid copper compound. As a result of my investigations, I have discovered that copper sulphate may be combined with one or more reaction agents in such a manner and under such conditions that the over product is substantially không tính tiền of copper sulphate or other acid copper compounds. That is, the product is neutral và chemically stable, but provides a high degree of fungicidal action.

Such a hàng hóa may be attained, for example, by combining copper sulphate & calcium hydroxide in such a manner và under such conditions that a true và complete reaction takes place, resulting in the formation of copper hydroxide và calcium sulphate. This reaction may be expressed, for purposes of explanation, by the simple equation: CuSO4+Ca(OH) 2=Cu(OH) 2+CaSO4 )0 Whether the reaction is that simple or more complex, the result is a stable và neutral compound as compared to lớn the unstable và complex character of Bordeaux mixtures in which the reaction is not true or complete.

36 According to lớn the present invention, in order to obtain a true & complete reaction, the compounding is effected in the presence of heat.

This may preferably be accomplished by heating a solution of copper sulphate và adding it khổng lồ the calcium hydoxide. In carrying out the invention lớn what is now considered the best advantage, I heat a copper sulphate solution to lớn about 160* F. While the temperature may vary, it should preferably be kept within the range of 150o-170* F. If the solution is not sufficiently heated the reaction takes place so slowly as to lớn be uncertain; if the solution is too hot, the result is apt lớn be the formation of black copper oxide & other undesirable products. The heated solution is then added slowly lớn an aqueous suspension of calcium hydroxide, which necessarily -includes lime water (calcium hydroxide in solution, to the extent of its solubility).

While the above described procedure is considered as preferable, It is not essential. The desired results may be attained by applying the heat in a different manner. For example, the calcium hydroxide may be heated, e. G. Lớn 800 or 90° F., the copper sulphate solution added there0O to, và the whole heated lớn about 160° F.

While the relative proportions of the two ingredients may vary, in carrying out the invention khổng lồ what is now considered the best advantage, not only should there ultimately be no unreacted copper sulphate present but in addition there should be no unreacted calcium hydroxide.

The desired end -may be attained in various ways. For example, there can be used enough & just enough copper sulphate to lớn satisfy completely the reaction with the calcium hydroxide.

That is, under what may be termed ideal conditions, the ingredients are present in molecular proportions.

Under the conditions of compounding above i7 described, a true và complete reaction takes place and with the ingredients present in molecular proportions the reaction is completely satisfied. The resulting compound, being substantially không lấy phí of copper sulphate or other acid copper compounds, is và remains stable and neutral; being substantially không tính phí of any unreacted calcium hydroxide, the compound has a maximum of copper hydroxide & so has a maximum fungicidal efficiency without having harmful effects on plant life. The compound may be used in this liquid khung as a so-called freshly made fungicide or it may be allowed to lớn settle and the precipitate dried & milled. In the latter case, the resulting dry powder is what may be termed the commercial form of the compound and may be used dry or may be later mixed with water for spraying as occasion may demand.

It is recognized that it may be difficult to realize, in commercial practice, the ideal conditions, as lớn relative proportions, above referred to. According khổng lồ the invention in its entirety, therefore, the same ultimate end, namely, an kết thúc product having substantially no unreacted copper sulphate or calcium hydroxide, may be attained in other ways. For example, it may be done by using a slight excess of copper sulphate in the reaction described and then freeing the reaction products of any unreacted copper sulphate that 30 remains.

This may be accomplished in various ways.

For example, it may be accomplished by neutralizing the remaining copper sulphate by means of a second reaction agent. Or the remaining copper sulphate may be removed physically by repeated decantations after settling. Or a combination of those methods may be utilized.

While the neutralizing agent may vary, sodium carbonate has been found suitable. It is to be understood, however, that other alkaline hydroxides and carbonates may be used.

According khổng lồ a procedure that has been found satisfactory, the first reaction is carried out as above described except that a slight excess of copper sulphate is used. This reaction may be expressed, for purposes of explanation, by the simple equation: CuSO4+Ca(OH) 2+;CuSO4= 50 Cu(OH) 2+CaSO4+XCuS04 where x equals the excess amount of copper sulphate.

As a result of this reaction the calcium hydrox- 55 ide is completely reacted but there remains a slight amount of unreacted copper sulphate.

The mixture is allowed to lớn settle & the bulk of the liquid is decanted. This decanted material will contain the greater part of the remaining copper sulphate. Then the neutralizing agent, e. G. Sodium carbonate, is added and the mixture is thoroughly agitated to lớn permit the sodium carbonate khổng lồ combine with the copper sulphate. As a result, copper carbonate và sodium sulphate are formed.

This may be expressed, for explanatory purposes, by the simple equation: Cu(OH) 2+2CuSO4+2NaaCO3+H20= Cu(OH)2+CuCO3, Cu(OH)2+2Na2SO4+CO2 As before, the resulting compound may be used as freshly made fungicide or it may be allowed khổng lồ settle and the precipitate dried and milled, givin, the commercial khung of the compound.

w ~-~ If no neutralizing agent is khổng lồ be used, water is added after the first decanting, the mixture further agitated and again allowed lớn settle. The water is again decanted, thus removing more copper sulphate & these steps are repeated until all the remaining copper sulphate has been removed. The final precipitate is dried & milled lớn obtain the commercial khung of the product. If the freshly made khung is desired the necessary water is re-added following the final decanting.

Whether or not an excess of copper sulphate is used in the formation of the compound, the result in either case is a copper fungicide that avoids all the above mentioned objections khổng lồ Bordeaux mixtures. In the first case, there is no remaining copper sulphate and so no undesirable reaction products. In the second case, by the neutralization or removal of the excess copper sulphate the reaction products are freed of acid, the copper carbonate is not subject to lớn reaction with the copper hydroxide and the ultimate result is the same.

The resulting compound is a neutral and stable copper fungicide that is reliable, safe & efficient.

As it is neutral & stable, the dosage can be adjusted with certainty whereby it can be applied to even the more delicate types of plants with safety. Being stable, it is equally safe và effective regardless of age & so provides a satisfactory commercial size of fungicide. It is economical lớn produce. It can be used effectively either in liquid size or as a dusting powder. It can be mixed with most wetting, spreading và sticking agents. Since no excess lime is used or required, the compound has a greatly Increased fungicidal kích hoạt in proportion to lớn the actual copper nội dung and less metallic copperis necessary as compared to Bordeaux mixtures. The compound, moreover, can be finished lớn a maximum particle fineness, insuring close association with leaf surfaces.

The invention in its entirety includes a compound for treating plants comprising essentially a neutral & stable copper fungicide and an insecticide of the sulphur or organic type. The copper fungicide above described, being neutral và stable may be mixed with a sulphur insecticide without the formation of copper sulphide or other undesirable copper compounds. It may also be mixed with organic insecticides such as rotenone và pyrethrum, without decomposition of the latter. Such combined fungicides & insecticides result in a high degree of economy khổng lồ the user since both a fungicidal and an insecticidal kích hoạt are obtained with one application instead of separate applications.

It is khổng lồ be understood that where the compound of the present invention is referred to lớn in the claims herein, the terms "fungicide" and "compound" are intended to include, unless otherwise specified, the fungicidal compound either in liquid size or in dry form and, if in 685 liquid form, either with or without having passed through a dry.form.

What is claimed is: 1. The method of producing a neutral & stable copper fungicide, which comprises combining a copper sulphate solution và calcium hydroxide in such proportions that the copper sulphate is present in excess of molecular proportions, applying heat so as khổng lồ give the mixture a temperature sufficient lớn cause a substantially complete reaction lớn take place, and neutralizing the unreacted copper sulphate remaining from the first mentioned reaction.

2. The method of producing a neutral and stable copper fungicide, which comprises combining a copper sulphate solution and calcium hydroxide in such proportions that the copper sulphate is present in excess of molecular proportions, applying heat so as khổng lồ give the mixture a temperature sufficient to lớn cause a substantially complete reaction lớn take place, & adding a material selected from the class consisting of alkaline hydroxides and carbonates to neutralize the unreacted copper sulphate remaining from the first mentioned reaction.

3. The method of producing a neutral and stable copper fungicide, which comprises combining a copper sulphate solution and calcium hydroxide in such proportions that the copper sulphate is present in excess of molecular proportions, applying heat so as to give the mixture a temperature sufficient to lớn cause a substantially complete reaction to lớn take place, and adding sodium carbonate khổng lồ neutralize the unreacted copper sulphate remaining from the first mentioned reaction.

4. A neutral & stable fungicide comprising the reaction hàng hóa which results from combining sodium carbonate with the intermediate reaction hàng hóa which results from combining copper sulphate và calcium hydroxide in the presence of heat & with the copper sulphate present in excess of molecular proportions.

5. A neutral và stable fungicide comprising the reaction product which results from combining a material selected from the class consisting of alkaline hydroxides & carbonates with the intermediate reaction product which results from combining copper sulphate and calcium hy-i droxide in the presence of heat and with the copper sulphate present in excess of molecular proportions. 6. A composition of matter comprising the reaction product which results from combining copper sulphate & calcium hydroxide in the presence of heat & with the copper sulphate present in excess of molecular proportions. 7. The method of producing a neutral and stable copper fungicide, which comprises combining a copper sulphate solution and calcium hydroxide in such proportions that the copper sulphate is present in excess of molecular proportions, applying heat so as khổng lồ give the mixture a reaction temperature of between approximately 150° F. Và 1700 F., and neutralizing the unreacted copper sulphate remaining from the first mentioned reaction. 05 FRANK J.

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