MXPA97005678A - Act insecticide composition - Google Patents

Abstract

The present invention relates to: An active insecticidal composition that forms an oil-free emulsion of limited stability containing an aqueous phase and an oil phase. When this composition is sprayed on a target surface, the aqueous phase is at least partially removed from the oil phase in the air or at the time of touching the target surface. Consequently, this composition leaves no ugly milky residue. Likewise, it is highly effective to kill insect

Description

ACTIVE INSECTICIDE COMPOSITION BACKGROUND OF THE INVENTION FIELD OF THE INVENTION The present invention relates to an active insecticidal composition that forms an oil-free emulsion of limited stability.

This composition when sprayed on a target surface, leaves no unpleasant milky residue. In addition, it is highly effective in killing insects.

DESCRIPTION OF THE PREVIOUS TECHNIQUE Active insecticidal compositions are generally sprayed from a container such as an aerosol container, onto a target surface. For a successful sprinkling that is uniform and equally distributed, the composition must be homogeneous or almost homogeneous. Traditionally, many active insecticidal compositions have had a single homogenous oil phase. However, such compositions usually have a high flammability and contribute to volatile petroleum products in the atmosphere. To reduce the oil content, the compositions were developed to form a homogeneous, stable emulsion containing an aqueous phase and an oil phase, such as those described in the U.S. Patents. Nos. 3,159,535 and 3,303,091. The patent of E.U.A. No. 5,178,871 discloses a stable, double emulsion. However, when such compositions are sprayed onto a target surface, unpleasant milky residues that characterize the appearance of an emulsion often remain on the surface, at least until the composition is completely dried. Compositions have also been developed which form emulsions without water (or oil in water), wherein the aqueous phase is the continuous phase and the oil phase is the embedded or discontinuous phase, such as those described in the U.S. Patents. Nos. 4,822,613; 4,889,710 and 5,094,853. However, said compositions typically form a stable foam when sprayed on a target surface. In addition, if the active ingredient is dissolved or dispersed in the aqueous phase, the active ingredient does not effectively penetrate the surfaces of water-repellent chitin insects. The patent of E.U.A. No. 2,418,652 discloses an emulsion without water to which a cationic emulsifier has been added, although in an amount less than an emulsifying amount. The cationic material is believed to adjust the surface charge of the oil globules suspended from the emulsion without water to increase its ability to adhere to the surface of a generally negatively charged sheet. The patent of E.U.A. No. 1,707,466 discloses a concentrated, stable oil emulsion which can be diluted with water to form a stable dispersion of oil in water. Although the dispersion is described as being stable over time while in its container, it is said to be substantially broken by contact with the target surface to coat plants or insect eggs with oil, combating the scale of insects and killing the eggs of the insects. coated insects. No other insecticide other than the same oil is used. The patent of E. U.A. No. 4, 904,464 discloses an insecticidal composition containing cocodiethanolamide which is separated into different phases of water and oil, which, under agitation, form an unstable dispersion, as opposed to an oil-free emulsion, which is then separated immediately after assortment. subsequent to the agitation.

COMPENDIUM OF THE INVENTION The inventors hereby have discovered an active, novel insecticidal composition which leaves no unpleasant milky spots when sprayed on a target surface. The composition is also highly effective in killing a variety of insects, including cockroaches, ants, silverfish, crickets and spiders. In one embodiment, the present invention provides an active insecticidal composition that forms an oil-free emulsion of limited stability, comprising: an aqueous phase comprising water; an oil phase comprising a hydrocarbon solvent and at least one active ingredient; and an amount of an effective surfactant to form an emulsion without non-foaming oil of limited stability; whereby when the emulsion is first formed inside and then sprayed from a container, the aqueous phase is at least partially separated from the oil phase in the air or at the time of touching a target surface.

DETAILED DESCRIPTION OF THE INVENTION The active insecticidal composition of the present invention includes an aqueous phase and an oil phase. An active insecticidal ingredient that is soluble in oil and substantially insoluble in water dissolves in the oil phase. The active insecticidal composition of the invention forms an oil-free emulsion of limited stability. An emulsion made in accordance with the invention should be considered as of limited stability if it is virtually evident that at least one begins to separate in fifteen seconds from the end of vigorous manual agitation in a bottle or other closed container. An oil-free emulsion that has oil and water phases (or, as an equivalent term, a water-in-oil emulsion) is a type of emulsion in which the oil phase is the continuous phase and the aqueous phase is the phase embedded or discontinuous. Since the oil-free emulsion of this invention has limited stability, the aqueous phase and the oil phase of the composition are usually separated during storage, at least partially. When the two phases of the active insecticidal composition of the invention are mixed together, for example, by stirring or stirring in a container containing the composition, an emulsion without oil is formed, which is substantially free of foam but which is also homogeneous or almost homogeneous When this emulsion is sprayed from the container, the aqueous phase separates from the oil phase at least partially and preferably completely, while the emulsion continues to travel through the air or rapidly at the time of touching the target surface. Typically, the aqueous phase is separated within about 10 seconds after the emulsion has been sprayed. Preferably, the aqueous phase is separated in about 5 seconds, and most preferably, the aqueous phase is separated immediately after the emulsion has been sprayed. As a result, there is no unpleasant milky residue remaining which characterizes the appearance of an emulsion on the target surface. Many insects have a dermatosque ueleto made mainly of chitin, which has a water repellent surface. The water easily spreads from the chitin surfaces without much penetration into the pores of the insect surfaces. In the present invention, the aqueous phase is separated from the oil phase and runs, leaving the oil phase and its active insecticidal ingredient, dissolved, on the surface of the insect. The oil phase moistens the surface, resulting in the active insecticidal ingredient carried in the oil phase penetrating more effectively into the pores of the surface. Accordingly, the composition of this invention is highly effective in killing insects. Preferably, a surfactant is present in the composition in an amount that is effective to provide an emulsion of limited stability. If the amount of surfactant present is excessive, the emulsion may become too stable and take on an excessively milky appearance. That is, the aqueous phase and the oil phase will not separate sufficiently after spraying. If the amount of surfactant present is not sufficient, the composition can not form an emulsion, at all. Typically, the amount of surfactant is from about 0.03% to about 0.10%, preferably from about 0.05% to about 0.10%, by weight, based on the total weight of the composition. All nonionic, anionic, and cationic surfactants can be used in the compositions of this invention, provided the surfactant can cause the formation of an oil-free emulsion by manually stirring the composition in a bottle or can. Preferably, the surfactant has a hydrophilic / lipophilic balance (hereinafter referred to as an "HLB") of between about 3 and about 9. If the surfactant has an HLB greater than about 9, by stirring an emulsion can be formed without water, instead of an emulsion without oil. If the surfactant has an HLB less than about 3, it becomes difficult to form an emulsion in situ by stirring the container while maintaining the composition. Nonionic surfactants are the preferred surfactants used in the compositions of the present invention, since they generally exhibit low toxicity to non-target humans and animals and are non-corrosive. Cationic surfactants tend to be corrosive in commercially common metal containers, typically used to contain insecticidal sprays. The anionic surfactants can cause nasal irritation, if they breathe and can also cause the formation of foam. Examples of suitable nonionic surfactants include long chain fatty acid esters of polyhydroxy compounds such as glycol, glycerol, and sorbitol esters of oleic, stearic, palmitic and lauric acids.; polyethoxylated fatty alcohols having from 2 to 9 ethylene oxide units; and polyethoxylated nonyl phenols having from 2 to 9 ethylene oxide units. Preferred nonionic surfactants are sorbitan mono-oleate, and sorbitan monostearate, which are commercially available as Span® 80, Span® 60, and Span® 40, respectively, from ICI Specialty Chemicals. The very preferred nonionic surfactant for the composition of this invention is sorbitan mono-oleate. The oil phase of the composition of this invention contains a hydrocarbon solvent. The amount of the solvent present in the composition must be effective to dissolve the active ingredient and form an emulsion without oil. Typically, the hydrocarbon solvent is present in the composition in an amount of from about 0.5% to about 40% and preferably from about 5% to about 30% by weight, based on the total weight of the composition. Examples of suitable hydrocarbon solvents include aliphatic, aromatic and naphthenic solvents, and mixtures thereof. Examples of suitable aliphatic hydrocarbons include isoparaffinic and normal paraffinic solvents such as those commercially available from Exxon Chemicals of Houston, Texas under the trade names of ISOPAR® and NORPAR®. Examples of suitable aromatic solvents include benzene, toluene and xylene. Examples of suitable naphthenic solvents include dearomatized and naphthenic aromatics containing isoparaffins. Naphthenic solvents are generally commercially available as mixtures of naphthenic, normal paraffinic and / or isoparaffinic solvents. Examples of suitable naphthenic solvents that are commercially available include EXXSOL® D-40, D-60, D-80, D-110, and D-130 from Exxon Chemicals, Houston, Texas. A preferred hydrocarbon solvent for use in the present invention is a mixture of normal naphthenic and paraffinic solvents, commercially available as EXXSOL® D-60. A co-solvent that is soluble in both the aqueous phase and the oil phase can also be added to the composition of this invention. The co-solvent assists the solubilization of the active insecticidal ingredient in the oil phase and also accelerates the breakdown of the emulsion. Typically, the amount of the co-solvent present is from about 1% to about 5% by weight, based on the total weight of the composition. If the amount exceeds approximately 5%, the emulsion may not be formed. Examples of suitable co-solvents include alcohols such as methanol, ethanol, propanol and isopropanol. As described above, the composition of the present invention contains at least one active insecticidal ingredient in an amount sufficient to provide insecticidal activity. Any conventional active ingredient that is insoluble in water and soluble in the hydrocarbon solvent can be used. Examples of suitable active ingredients include, but are not limited to, natural pyrethrins, synthetic pyrethroids such as permethrin, cypermethrin, deltamethrin, alphamethrin, cyphenothrin, fenvolerate, allethrin, tetramethrin, resmethrin, bioresmethrin, d-trans-allethrin, and phenothrin, pyrethroid halogenated and cyano-pyrethroid. Typically, the active ingredient is present in the compositions of the present invention in an amount of from about 0.20% to about 2%, and preferably from about 0.10% to about 1% by weight, based on the total weight of the composition. A synergist for the active ingredient in the compositions of this invention may also be included in conventional amounts. Examples of suitable synergists include piperonyl butoxide and N-octyl-bicycloheptane-dicarboximide. The water forming the aqueous phase of the composition of the invention must be present in an effective amount to form an oil-free emulsion of limited stability and to facilitate spraying. When the composition is sprayed from a container, the water works as a filler to add volume to the sprayed product. Typically, water is present in the composition in an amount of fabout 30% to about 70% and preferably fabout 40% to about 70% by weight, based on the total weight of the composition. The active insecticidal composition of the present invention can be combined with a suitable propellant to form an aerosol formulation. Examples of suitable propellants include compressed gas propellants such as nitrogen, carbon dioxide, and nitrous oxide; liquefied gas propellants such as fluorinated and chlorinated hydrocarbons, dimethyl ether, vinyl chloride; saturated hydrocarbons such as propane, butane, and sobutane, isopentane, and mixtures thereof; and mixtures of liquefied gases and compressed gases. In order to reduce environmental pollution, it is preferred to employ liquefied saturated hydrocarbons as the propellant. Typically, the hydrocarbon propellant is present in the composition of this invention in an amount of from about 8% to about 50%, and preferably from about 5% to about 30% by weight, based on the total weight of the composition. Other ingredients that may be part of the composition of the present invention include fragrance in conventional amounts to mask the unpleasant odor of active ingredients and corrosion inhibitors such as nitrite, sodium benzoate, and mixtures thereof in conventional amounts to inhibit corrosion of metal containers, in which the composition is usually contained. The present invention will now be illustrated with the following non-limiting examples.

EXAMPLE An active insecticidal composition that can form an oil-free emulsion of limited stability was prepared with the following ingredients: Ingredients Percent in Weight Pyrethrin 20% 1,000 Permethrin 90% 0.222 Piperonyl Butoxide 0.500 Sorbitan Mono-Oleate 0.050 Fragrance 0.228 Isopropanol 1,000 EXXSOL® D-60 29,000 Sodium Nitrite 0.090 Water 59.910 Propellant A-91 8,000 The A-91 propellant is a conventional propellant containing 70% propane and 30% isobutane. The composition was prepared by dissolving the 20% pyrethrin, 90% permethrin, piperonyl butoxide, sorbitan mono-oleate, fragrance, and isopropanol in EXXSOL® D-60 to form a solvent intermediate. The sodium nitrite was dissolved in water to form a water intermediate. The water intermediate was then added to an aerosol container, followed by the solvent intermediate. Then, a valve was placed in the container and held. The vessel was then pressurized with the A-91 propellant. The vessel was then stirred to form an oilless emulsion of limited stability. Immediately afterwards, the composition was sprayed from the container to a target surface. It was observed that when the spray touched the target surface, the aqueous phase separated from the oil phase almost immediately. As a result, there were no unpleasant milky spots on the target surface. Since the present invention has been described with respect to what are currently considered the preferred embodiments, it should be understood that the invention is not limited to the embodiments described. Otherwise, the invention is intended to cover the various equivalent modifications and formulations included within the scope and spirit of the appended claims. The scope of the following claims has to be in accordance with the broadest interpretation in order to encompass such modifications and equivalent formulations and functions.

INDUSTRIAL APPLICABILITY Insecticidal spray compositions have immediate utility in the control of insect pests. The active insecticidal composition of the invention has the additional, industrially desirable application of providing a composition having a reduced concentration of volatile petroleum products, while remaining both suitable for spraying through conventional means and an effective insect spraying annihilator. .

Claims (19)

1. CLAIMS 1 .- An active insecticidal composition that forms an emulsion if oil of limited stability, comprising: an aqueous phase comprising water; an oil phase comprising a hydrocarbon solvent and at least one active insecticidal ingredient; and an amount of an effective surfactant to form an oil-free, non-foaming emulsion; whereby when the emulsion is formed inside and then sprayed from a container, the aqueous phase separates at least partially from the oil phase in the air or at the time of touching the target surface.
2. 2. The active insecticidal composition according to claim 1, wherein said surfactant is present in an amount of about 0.03% to about 0.10% by weight, based on the total weight of the composition.
3. 3. The active insecticidal composition according to claim 2, wherein said surfactant is present in an amount from about 0.05% to about 0.10%.
4. 4. - The active insecticidal composition according to claim 1, wherein said surfactant agent has an HLB of between about 3 and about 9.
5. The active insecticidal composition according to claim 4, wherein said surfactant is selected from the group consisting of nonionic, anionic and cationic surfactants.
6. 6. - The active insecticidal composition according to claim 5, wherein said surfactant is a nonionic surfactant.
7. 7. The active insecticidal composition according to claim 6, wherein said surfactant is selected from the group consisting of glycol, glycerol, and sorbitol esters of oleic, stearic, palmitic and lauric acids, polyethoxylated fatty alcohols having 2 to 9 units of ethylene oxide and polyethoxylated nonylphenols having from 2 to 9 units of ethylene oxide.
8. 8. The active insecticidal composition according to claim 6, wherein said surfactant is selected from the group consisting of sorbitan mono-oleate, sorbitan monostearate and sorbitan monopalmitate.
9. 9 - The active insecticidal composition according to claim 1, wherein said hydrocarbon solvent is selected from the group consisting of aliphatic, aromatic and naphthenic solvents, and mixtures thereof.
10. 10. The active insecticidal composition according to claim 1, wherein said composition further comprises a co-solvent.
11. 11. The active insecticidal composition according to claim 10, wherein said co-solvent is an alcohol.
12. 12. The active insecticidal composition according to claim 1, wherein said active ingredient is selected from the group consisting of natural pyrethroids, synthetic pyrethroids, halogenated pyrethroids and cyano-pyrethroids.
13. 13. The active insecticidal composition according to claim 1, wherein it further comprises a synergist for said active ingredient.
14. 14. The active insecticidal composition according to claim 13, wherein said synergist is selected from the group consisting of piperonyl butoxide and N-octyl-bicycloheptane-dicarboximide.
15. 15. The active insecticidal composition according to claim 1, wherein it further comprises a propellant.
16. 16. The active insecticidal composition according to claim 15, wherein said propellant is selected from the group consisting of liquefied saturated hydrocarbons and mixtures thereof.
17. 17. The active insecticidal composition according to claim 1, wherein said composition further comprises a fragrance.
18. 18. The active insecticidal composition according to claim 1, wherein said composition further comprises a corrosion inhibitor.
19. 19. The active insecticidal composition according to claim 18, wherein said corrosion inhibitor is selected from the group consisting of sodium nitrite, sodium benzoate, and mixtures thereof.