US2418652A - Insecticidal compositions - Google Patents

Description

unirso STATES TENT QFFICE 2,418,652 INSECTICIDAL COMPOSITIONS Application May 28, 1942, Serial No. 445,106

6 Claims. (CL-167-43) This invention, a continuation-in-part of my application, Serial No. 409,195, filed September 2, 1941, relates to new and improved insecticidal compositions and more particularly pertains to a new and improved agent for depositing insecticidal material from an aqueous carrier.

A primary object of this invention is to provide an additive for insecticidal compositions capable of yielding increased deposits of said materials when sprayed on foliage, fruits, or dormant trees. Thus, mineral oils, which have long been used as insecticidal sprays, are usually applied in the form of an emulsion with water. For foliage spraying, they are ordinarily emulsified with 96-99% of water, and in dormant spraying with as little as 95% of water. The water acts as a carrying agent for the oil and effects a distribution of the oil over the plant. However, the water also carries considerable quantities of the oil from the sprayed object.

It is towards minimizing the carrying off of the oil and increasing the deposition thereof from an aqueous carrier that the instant invention is directed. It will be obvious that, with increased deposition of the insecticidal material, savings thereof will be effected and a lower concentration of oil in the water will be required to obtain lethal dosage. A further object is to provide a depositing agent which will cause the insecticide to adhere firmly to the fruit or foliage.

The term insecticidal material" or suspensoid as used herein refers to mineral oils either with or without the addition of toxicants. Such toxicants may comprise pyrethrum, rotenone, derris resins, nicotine, aliphatic thiocyanates, dinitro cresols, dinitro phenols, ketones, ketols, halogenated hydrocarbons such as chlorinated naphthalenes, cresylic acid, alkyl amines, pine Oils, etc.

Ihave discovered that when suitable cation surface-active emulsifiers are added in amounts which do not cause emulsification to an aqueous carrying medium containing an insecticidal suspensoid and this mixture sprayed on fruit or foliage, a smooth and uniform deposit of unusual magnitude of the insecticidal material is obtained.

, The invention will be more clearly understood from the following detailed description.

The effect of cation surface-active compounds as depositing agents may be explained on the basis of electrokinetic phenomena. Emulsified oil globules, as Well as wet leaf surfaces, normally possess negative electrostatic charges. The mineral oils are normally emulsified for spray purposes either by mechanical agitation in the spray machine 2 alone or by such agitation and addition of oilsoluble emulsifiers. Such emulsifiers may comprise alkyl sulfonates and sulfates such as petroleum sulfonic acids and their oil-soluble sodium, potassium, or ammonium salts; fatty and naphthenic acid soaps; certain fatty acid esters of polyhydric alcohols, polymerized animal and vegetable oils and nonionic emulsifiers such as monostearyl, lauryl, and oleyl ethers of polyethylene glycol. Most of these commonly used agents are anion-active and some few are electrically neutral. They therefore either further increase the negative potential on oil globules and leaf surfaces or else have no, or but slight, effect on the electrostatic charge. The magnitude of the negative charge is directly related to the stability of the emulsion on the leaf and, consequently, emulsions containing conventional emulsifiers do not readily break to deposit the insecticidal material. In keeping therewith, I believe the effectiveness of the cation surface-active compounds as depositing agents to be due to a reduction in the negative charge or the establishment of a slight positive charge on the emulsified oil globules and a consequent reduction in the stability of the emulsion when in contact with the negatively charged leaf. However, as will be explained later, the quantity of cation-active additives must be kept below a certain maximum in Order to be effective for increasing deposits of the insecticidal material. If quantities of the additives above the predetermined maximum are employed, the additives are inefiective as depositing agents. The critical feature of the quantity added is believed to be due to such a complete reversal of the charge on the oil globules when more than certain amounts are added that an emulsion results of positively charged oil globules of sufficient stability to be carried off by the water despite the attraction ofiered by the opposite charge of the leaves.

It follows, therefore, that less than an emulsifying amount of cationic additive should be employed, i. e. an amount of the additive less than that which will render an emulsion of the mineral oil. insecticidal material more stable than prior to the addition of my additive. In general, effective quantities of my additive may range from about .01% to 1% by weight of the oil, depending upon the particular additive chosen. A preferred amount for several cationic surface-active compounds has been found to be about .1%. Although amounts within the aforementioned range are effective and generally below the amount required for increased emulsification of the insecticidal material, this latter amount, or upper limit, can be readily ascertained by a To facilitate a better understanding of the invention, it is perhaps Well to first consider comparison between the wetting agents or emulsifiers of the anion type which are commonly used in spray oils.

fore negatively charged and is anion-active.

, H Examples of this type are as follows:

If the sodium ion in the foregoing examples were replaced by a surface-active lipophilic orhydrophilic anion radical. The additive should be soluble to the desired extent in either the oil than %,preferably 1% or less;

A preferred group of cation surface-active A suitable organic radical contains a lipophilic group sucl\as, and preferably, a hydrocarbon group of at least eight carbon atoms. The or ganic radical may also contain a chain comprisformation.

The anion may be the anion of any acid having hydrophilic properties being devoid of surface activity and being stable and inert under normal conditions of use, or it may be a hydroxyl group.

especially suitable. The requirement of surface activity excludes such acids as oil-soluble sulfonic acids and the requirement of inertness excludes chromic, perboric, chloric, etc.

efiective. The quaternary ammonium and phosphonium compounds may be represented by the general formula:

wherein X stands for nitrogen, or phosphorus; R is a hydrocarbon or substituted hydrocarbon cal may be replaced by a chloride, iodide, acetate, sulfate, nitrate, etc., substituent. bus, for example, cetyl trimethyl ammonium chloride (C16H33 (CH3)3NC1) 2. Fatty acylated nitrogen bases and alkylated pyridine derivatives: Many of these materials are insoluble in Water but are made soluble by acidulating the Water.

Pyridinium salts may be prepared by reacting alkyl halidessuch as cetyl bromide with pyridine:

When this is added to water, the following reaction takes place:

3. Triethyl hexadecyl phosphonium bromide, (C2H5)3-P(BI)C16H33, dodecyl-trimethyl-p h S- phonium bromide, C12H25(CI-Iz)sPBr, or similar compounds.

4. Lauryl quinaldinium bromide:

is oleyl, but may also be, for instance, lauryl, myristyl, stearyl, etc., and R" represents hydrogen, alkyl, aryl, or substituted alkyl or aryl radicals, and Z is a hydrophilic acid anion or hydroxyl ion.

Also found effective for the purpose of this invention are the ternary sulphonium salts which are similar except for the lesser valence of the nuclear atom to the quaternary ammonium and phosphonium salts described under the above general formula. The compound,

Me.Et.S.(SO4ME) clans or other tetravalent sulfur compounds such as di-ethyl octadecyl sulphonium chloride may be mentioned as illustrative of suitable sulphonium salts.

A preferred group of cation surface-active depositing agents may be prepared from the basic condensation products of organic carboxylic acids and amino-alcohols or diamines, or similar com-' pounds having a lipophilic group of at least eight carbon atoms and being cation surface-active Wetting agents.

This type of basic compound forms salts by reaction with hydrophilic acids, for example monobasic acids, such as hydrochloric and hydrobromic acid, acetic acid, propionic acid, etc., dibasic acids, such as malonic, malic, maleic glutaric, etc., or, under proper conditions, with alkyl or aryl substituted mineral acids, which salts are cation-active. Thesebasic compounds may be used as their salts in the present invention.

These basic compounds, which may be used to form the cation surface-active compounds of the present invention, may be designated by the general formula wherein R is a hydrocarbon or acyl group containing a terminal hydrocarbon group of at least eight and preferably ten carbon atoms, depending on the number and strength of the hydrophiiic groups in the molecule, and which may contain non-functional substituents; and R1 and R2 are hydrogen or hydrocarbon radicals such as hydrogen, alkyl, aryl, aralkyl, etc., radicals, which may contain hydroxy or alkoxy radicals, halide atoms, etc.

Below are several groups of these basic compounds, which are given here merely by way of illustration:

1. Compounds of the type R- 3-1 I-cHr0Hr-N= ogm)i 2. Compounds of the type R-( J-o-cmcHr-NR'1 Especially suitable compounds for my purpose are the salts of hydrophilic acids, e. g., malic acid, and the basic condensation products of high molecular weight carboxylic acids or mixtures of different high molecular weight carboxylic acids,

e. g. palmitic and stearic acids, with alkanol.

amines. Thus, for example, the salt of malic acid and the acid amides produced by condensing a mixture of paimitic and stearic acid with ethanol ethylene diamine is particularly efiective for my purpose. This salt will for convenience, be referred to hereinafter as the malate of EXAMPLE I The efiectiveness of the depositing agents was determined under conditions simulating field practice. Spray oils to be tested both with and without the herein described depositing agents were emulsified with water in a small field-type spray machine capable of operating at spraying pressures up to 1000 lbs. Numerical evaluation of the spray deposits for the various oils and additives tested was obtained by spraying weighed four-ounce oil sample bottles, the sides of which had been coated with a thin layer of beeswax. The bottles were weighed to the nearest 1% milligram on an analytical balance before spraying, and again after spraying, and allowing sufiicient time to elapse so that all water from the spray had evaporated. The drying was expedited by placing the bottles in a stream of dust-free air.

The area of the side of the four-ounce sample.

bottles averaged close to 150 sq. cm., and, since they were sprayed in sets of 3 for each test, following equation can be derived:

cidal composition in the spray machine--- 30 Spray nozzle orifice diameter, inches %4.

Distance spray nozzle to the sample bottle,

feet i 1'. 6 Exposure of sample bottles to spray, seconds 6 Water hardness P. P. M. as CaCOa ,l...

the

Results Sample QL AZQ OIiEl Dcp. on F Depo slit t Number. eeswax actor es 0f Spray Deposltmg Agent gg ggg Micro- Oil/Standoil l on grams/0mg and 1 None None 150 l O The mal'ate of C and "H31 a nsC-NH-CHzOHzNHCHzCHzOH. 5 310 2.07 Agent A- l 3l5 2.10 Agent B 5 337 2. Agent 0- 5 312 2.08 6 9 Agent D 5 279 1. 88

1 A light medium oil of 68 S. S. U. V. at-l0O F., 92% U. R.

Commercially available cation surface-active emulsifiers whose cation active properties were determined by cataphoresis. employing a method similar to that described in the transactions of the Faraday Society, vol. 36. pages 5l5,

1940, by H. A. Abramson, under title of Microscopic method of electrophoresis and its application to the study of iono- 1 genie and nonionogenie surfaces.

EXAMPLE II 20 ursed ivHarnd.asC-NH-CH2CHzNHCHzCHzOH (i. e. the salt of malic acid and the acid amides produced by condensing a mixture of palmit-ic and stearic acids with alkanol ethylene diamine) a cation surface-active compound, were emulsifled in the laboratory spray apparatus as described above. For each test, 250 ml, of emulsion were removed from thespray tank, placed in a modifiedCassia flask, and the oil allowed to separate. for an hour. After standing for this period,

a 50,- cc.,'sample of the water. layer was removed from the flask with a pipette and placed in a Babcock bottle and centrifuged to remove the remaining oil which had not separated or which had not been demulslfied by standing. The per cent. of oil separated by centrifuging for the various samples tested was measured, with results as. shown in the table below:

Emulsifyzng conditions Oil dosage, per cent concentration 1.67 Pressure, lbs/sq. in 500 Circulation time, sec 30 11 Oil contained 2% cresylic acid by volume as a mutual solvent for the depositing agent.

It will be understood that the insecticidal compositions of my invention may contain other additives, such as antipenetrants like glyceryl oleate, glyceryl mono-oleate, aluminum naphthenate, visco resins, aluminum stearate, triethanolamine, cottonseed oil and similar fatty oils, etc., spreading agents such as blood albumin and/or with other known depositing agents like ketones, etc.

The cation surface-active depositing agents which have been described in the foregoingare merely illustrative of compounds useful for my purpose. It will be understood that the compounds meeting the tests described herein as to operatlveness for my purpose and equivalentsareincluded within the scope of the invention.

While I have-advanced certain theories of operation for my newly invented depositing agentsfor insecticidal materials, it will be understood that I do not limit myself to any such theory of operation set out, but only to the invention as.

set out in the following claims.

I claim as my invention:

1. An insecticidal composition essentially comprising a mineral. oil, and. insecticidal toxicant, and between about 0.01% and about 1.0% (by weight of the oil) of a cation surface-active depositing agent, said composition being capable of forming an unstable emulsion with water.

2. An insecticidal composition essentially comprising a mineral oil, and insecticidal toxicant, and a cation surface-active depositing agent in an amount of the order of about 0.1% by weight Results Grams 8f the malate of lgerccntt Oil.

eparo ion from Water um er 015 a "H31 and 35CNHOH2CH2NHCHZCH2OH Layer by per 100 1111. oil Centrllugrug None 0. 5 0. l0 0 1 0. 50 0. 3, 0. 75 0. 4 1. 0O 0. 5 2. (l0 0. 7.

The attached drawing shows the amount of deposit obtained with the spray oil containing various amounts of the malate of under conditions as described in Example I above.

and the. acid amide condensation product. of a;

fatty acid with an alkanol amine, said compost.-

9 tion being capable of forming an unstable emulsion with water.

4. An insecticidal composition essentially comprising a mineral oil, and insecticidal toxicant, and between about 0.01% and about 1.0% (by weight of the oil) of the malate of the condensation product of ethanol ethylene diamine and a mixture of stearic and palmitic acids, said composition being capable of forming an unstable emulsion with water.

5. An insecticidal composition essentially comprising a mineral oil, and insecticidal toxicant, and between about 0.01% and about 1.0% (by weight of the oil) of a cation surface-active depositing agent and a minor amount, based on the ,Weight of said oil, of a mutual solvent for said cation surface-active depositing agent, said composition being capable of forming an unstable emulsion with water.

6. An unstable insecticidal emulsion of a mineral oil in water essentially comprising said mineral oil, an insecticidal toxicant, water, and between about 0.0l% and about 1.0% (by weight of the oil) of a cation surface-active depositing agent.

KENNETH E. MAXWELL.

10 REFERENCES CITED The following references are of record in the file of this patent: I

UNTTED STATES PATENTS Number Name Date 1,405,856 Morgan Feb. 7, 1922 1,934,057 Grant Nov. 7, 1933 1,940,646 Grant Dec. 19, 1933 10 2,134,917 Harris Nov. 1, 1938 2,139,277 Lehner Dec. 6, 1938 2,151,783 Maversberger Mar. 28, 1939 2,202,387 Kunz May 28, 1940 2,206,928 Ulrich July 9, 1940 15 2,362,760 Maxwell Nov. 14, 1944 FOREIGN PATENTS Number Country Date 393,276 British 1933 OTHER REFERENCES Martin, Scientific Principles of Patent Protection," 2nd edition, 1937, pages 85-86.

Dean, Utilization of Fats, 1938, pages 288, 25 289.

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