IE54464B1

IE54464B1 - Aqueous pesticide concentrates

Info

Publication number: IE54464B1
Application number: IE974/82A
Authority: IE
Original assignee: Ciba Geigy Ag
Priority date: 1981-09-09
Filing date: 1982-04-26
Publication date: 1989-10-25
Also published as: BG38781A3; DK187882A; FI821482A0; TR21438A; ATE37468T1; AU555932B2; RO93895B; DD202229A5; DK163554C; IE820974L; GR75428B; FI69235B; IL65674A0; EP0074329A2; FI821482L; JPS5846001A; EP0074329A3; OA07094A; AU8312382A; HU196878B

Abstract

1. An aqueous solution concentrate comprising alph) a liquid or solid pesticide that is stable in water and less than 1 % soluble in water and has a water number greater than 10, and beta) a salt of an aromatic sulphonic acid having the formula see diagramm : EP0074329,P8,F1 wherein R1 , R2 and R3 have the same or different meanings and each is hydrogen or straight-chain or branched C1 -C6 -alkyl, Z is a direct bond or a straight-chain or branched C1 -C6 -alkylene bridge and R4 is an alkali metal, an ammonium group, a primary, secondary or tertiary amine group, a hydroxyalkylamine group or a morpholine group, in an amount sufficient to form an aqueous solution.

Description

The present invention relates to aqueous pesticidal concentrates of liquid and/or solid active ingredients that are sufficiently stable in water and are waterinsoluble, which concentrates can be diluted by the user for spraying, and to a method of producing such formulations. i-iany pesticidal active ingredients can be regarded, from the formulation chemist's point of view, as being waterinsoluble. Their water-solubility is usually less than i.o % w/v; however, this does riot limit the invention in any way. Dissolving these compounds in an aqueous medium to form an aqueous concentrate has hitherto been difficult and in many cases impossible. Where it has been possible, the end product has too low a concentra15 tion, a poor shelf life, poor low-temperature stability and is generally commercially unacceptable. Therefore, conventional non-aqueous formulation techniques are usually adopted for these active ingredients or aqueous suspensions are produced if the active ingredient has a melting point of at least 70‘C.

The type of formulation chosen depends on the physicochemical properties of the active ingredients used.

There are three different categories: 1. Emulsifiable Concentrates (EC) - if the active ingredient is soluble in oils.

An emulsifier or surface active agent is necessary in this type of formulation to ensure that the product forms a homogeneous emulsion when diluted with water for use. The main advantage of this type of formulation is that the product is a liquid. Disadvantages of this type of formulation are: firstly, large amounts of potentially harmful and expensive solvents are required and, secondly, for safety reasons, these formulations are often packed in expensive aluminium or tinplate containers. 2. Wettable or Dispersible Powders (WP) - if the active ingredient is insoluble in oils.

Surface-active agents are required in this type of formulation to ensure complete dispersion of the product when diluted by the end user with water. The main disadvantages of this type of formulation are: firstly, that it is a powder and hence a potential dust hazard and, secondly, that the powder has to be weighed in the field by the user and cannot be measured out by volume as a liquid can. 3. Aqueous Suspension Concentrates (SC) - if the active ingredient is insoluble in oil and water and has a melting point of more than 70’C.

In this type of formulation the active ingredient is finely milled and suspended in water with the aid of surface-active substances. The main advantage of this type of formulation is that it is a liquid. The disadvantages are that it tends to form non-resuspendable sediments and it cannot be used for liguid and lowmelting active ingredients, even when the latter are to be used only as co-ingredients.

Consequently, if an active ingredient is soluble in oils it can be formulated as a liguid emulsifiable concentrate. If, however, it is insoluble in oils, then it is usually formulated as a wettable powder, or as a suspen30 sion concentrate if the melting point is high enough.

All three types of formulation have major disadvantages, 544 6 4 the wettable powder more so than the other two.

French Patent Applications FR-A-2187226 and FR-A-2187227 disclose micro-emulsions of insecticidally and herbicidally active agrochemicals. Apart from the agrochemical active ingredient these micro-emulsions, which are formulated on an aqueous basis, also contain an emulsifier and a hydrotrope.

The micro-emulsions are already diluted to application concentration and may contain up to 5% active ingredient.

The low active ingredient concentrations that can be obtained with this type of formulation require considerable outlay on storage and packaging.

We have now found that many of the disadvantages associated with the formulation of the active ingredients mentioned in this Application can be overcome by the novel formulation technique of the invention.

The principal objective of the invention is to provide aqueous pesticidal solution concentrates of water-stable and water-insoluble pesticidal active ingredients, which concentrates are to be storage-stable and dilutable with water to produce relatively stable emulsions or dispersions.

A further objective of the invention is to provide a method of formulation that permits a pesticidal active ingredient of the mentioned type to be combined with a water-insoluble solid active ingredient which cannot itself be formulated by the method of the invention.

The objectives of the present invention are achieved by the use of aromatic sulphonic acids and their salt derivatives. This group of compounds is used as hydrotrope.

According to the invention, an aqueous solution concentrate is therefore provided comprising a) a liquid or solid pesticide that is stable in water and less than 1% soluble in water and has a water number greater than 10, and β) a salt of an aromatic sulphonic acid having the formula R. '2 (I) '3 wherein Rx, R2 and R3 have the same or different meanings and each is hydrogen or straight-chain or branched Οχ-Cgalkyl, Z is a direct bond or a straight-chain or branched Cx-C6-alkylene bridge and R4 is an alkali metal, an ammonium group, a primary, secondary or tertiary amine group, a hydroxyalkylamine group or a morpholine group, in an amount sufficient to form an aqueous solution. The aqueous solution concentrates of the invention may be produced simply by dissolving a compound (a) in an aqueous solution of a compound (β).

The aqueous solution concentrates of the invention preferably contain up to 75 % w/v of active ingredient (component a), most preferably 5 - 50 % w/v, and up to 70 % w/v of pure hydrotrope (component β), most preferably 15 - 50 % w/v.

Typical examples of compounds of formula I are ammonium cumenesulphonate (commercially available as a 60 % (, 5 4.4 6 4 aqueous concentrate), potassium xylenesulphonate (commercially available in solid pure form and as a 40 % aqueous solution), sodium cumenesulphonate (commercially available in solid pure form), sodium toluenesulphonate (commercially available in solid pure form and as a 40 % aqueous solution), and xylenesulphonic acid (commercially available as a 90 % liquid dilutable with water).

The degree to which the pesticide is soluble in the hydrotrope is dependent on three properties: 1) the water-solubility of the pesticide (or an indirect measure of its water-solubility, such as the water number which can be determined by the method of Greenwald, Brown and Finemann, Anal. Chem. 28, 1693 (1956)), 2) the chemical structure of the hydrotrope, and 3) the concentration of the hydrotrope in the formulated product.

As a general rule, liquid pesticides having a water number less than 10 are too lipophilic and not suffi20 ciently soluble in aromatic sulphonic acid (salt) solutions to make them of any commercial interest whereas pesticides having water numbers above 10 can be formulated as commercially viable aqueous-based products using suitable aromatic sulphonic acids or salts thereof.

Surprisingly, it was found that once the pesticide is dissolved in this hydrotrope, it will form an emulsion or a dispersion on dilution with water. This phenomenon can occur without the use of emulsifiers or surface-active agents which are necessary in the case of a conventional emulsifiable concentrate in a hydrocarbon solvent. 4-164 However, it may be helpful to add to the aqueous concentrates of the invention functional aids such as surfaceactive agents and additional solvents (for better leafwetting and active ingredient penetration and to avoid crystallisation of solid active ingredients from dilute aqueous solutions, i.e. from the spray mixture), tackifiers and thickeners (for better leaf adhesion and to control droplet size on application) and antifoams to avoid foaming.

Examples of such functional aids are: a) Surface-active agents and additional solvents: nonylphenol ethoxylates, e.g. those from the commercially available * Ethylan N range; alcohol and fatty acid ethoxylates, e.g. those from the commercially available *Ethylan C range; and hydrocarbon solvents, such as vegetable oils, mineral oils, methylphenols and polyglycol ethers, b) Tackifiers and thickeners: polyethylene glycols, polyacrylamide solutions and polyvinylpyrrolidones, and c) Antifoams: silicone-based compounds and emulsions, fatty acids, e.g. coconut oil and ethylene oxide/propylene oxide block co-polymers, such as the commercially available Pluronic polyalcohols.

Examples of liguid and solid active ingredients which are particularly suitable for use as components (a) in the novel concentrates are listed in the following Tables: * Trade Mark Table 1; Liquid active ingredients; active ι Ingredient Class of Active Ingredient Normal Formulation Novel Formulation on Aqueous Basis — Hetolachlor Acetanilide EC (500 β a.i./l) ECU (300 g a.i./l) Propiconazole Triazole EC (250 g i.i./l) ECU (250 g a.i./l) UP (250 g a.i./kg) ImazaliI Diazole EC (500 g a.i./l) ECU (500 g a.i./l) Tridenorph Horpholine EC (750 g a.i./l) ECU (500 g a.i./l) Chlorfenvinphos Phosphate EC (300 g a.i./l) ECU (300 g a.i./l) Table 2; Solid active ingredients . Active 1 Ingredient Class of Active Ingredient Normal Formulation Hovel Formulation on Aqueous Basis i 15 Metalaxyl Acylalanine UP (250 g a.i./l) ECU (250 g a.i./l) 20 2-(2,4-Di- chlorophenyl)- triazol-Vyl)- : pentane Triazole EC (100 g a. i./l) ECU (100 g a.i./l) EC = Emulsifiable Concentrate WP = Wettable Powder ECW = Emulsifiable Concentrate as aqueous solution a.i. = active ingredient.

Although some water-insoluble solid active ingredients are soluble in these hydrotropes, many water-insoluble solid active ingredients are not soluble therein to any appreciable extent. It is therefore also an objective of the present invention to provide a combination product 4 4 6 4 containing two or more active ingredients having a broader spectrum of action, using the aromatic sulphonic acid salt solution as both a suspending and a dissolving reagent.

The invention therefore also relates to aqueous concentrates that contain, in addition to components (a) and (β) defined hereinbefore, as further component (v), a solid pesticide that is not soluble in the hydrotrope.

These three-component aqueous concentrates of the invention may be produced by preparing a solution of component (a) in (β), preferably, but not necessarily, with the use of a surface-active agent, and then adding component (-r) to the resulting solution and optionally milling the mixture to the desired particle size of the solid component (v) .

The resulting formulation is: i) a liquid ii) aqueous based iii) physically and chemically stable at high and low temperatures iv) dilutable with water to form a stable spray liquor suitable for spraying, and v) non-dusty compared with the equivalent wettable powder.

The use of aromatic sulphonic acid salt solutions as hydrotrope and/or as suspending medium for solid pesticides has the following advantages: a suspension prepared using these hydrotropes may not require the addition of antifreeze agents or suspending aids since the commercial solutions of these hydrotropes can impart all these properties to the final product. 4 4 6 4 This technique can also be successfully used to combine other liquid or solid active ingredients with further solid pesticides not soluble in the hydrotrope. Examples are shown in the following Tables: Table 3: Combinations of liquid and solid pesticides: Liquid (a) Propiconazole Propiconazole Metolachlor Imazalil Solid (ΥΊ + Captan + Carbendazim + Atrazine + Thiabendazole Table 4: Combinations of two solid pesticides: Solid fa) Metalaxyl Metalaxyl Metalaxyl 2-(2,4-dichlorophenyl )-1-(1H-1,2, 4-triazol-l-yl)pentane) Solid hr) + Copper oxychloride + Ziram + Folpet + Copper oxychloride The following Examples illustrate the present invention in more detail: Comparative Example A (Normal Formulation) Propiconazole 250 g/1 Emulsifiers 100 g/1 Hydrocarbon/aromatic solvents to 100 % by volume Example 1; Propiconazole 250 g/1 60% ammonium cumenesulphonate solution to 100% by volume.

As can be seen from the details above, both formulations contain the same concentration of active ingredient; however, Example 1 has the following advantages over Comparative Example A: i) it does not contain any potentially harmful solvents ii) it has no flash point iii) it contains no emulsifiers iv) it can be packed in polyethylene containers and v) it is less toxic because it is aqueous-based.

Example 2: Propiconazole k Soprophor FL (ex Rhone Poulenc) 40% ammonium xylenesulphonate solution Example 3: Metolachlor * Tween 85 (ex Atlas Chemicals) 60% ammonium cumenesulphonate solution 125 g/1 g/1 to 100% by volume 300 g/1 g/1 to 100% by volume Example 4; chlorfenvinphos 300 g/1 *Emulsogen EL (ex Hoechst AG) 25 g/1 ethylene oxide/ propylene oxide block co-polymer 25 g/1 * Trade Mark 4 4 6 -1 60% ammonium cumenesulphonate solution to 100% by volume.

Example 5; 2-(2,4-Dichlorophenyl)-1-(1H-1,2,4- triazol-l-yl)-pentane 100 g/1 cyclohexanone 50 g/1 xylene 50 g/1 * Emulsogen EL (ex Hoechst AG) 25 g/1 Nonylphenol polyglycol ether (8 to 10 12 mol EO) 25 g/1 60% ammonium cumenesulphonate solution to 100% by volume.

Examples 1 to 5 are prepared by dissolving the active ingredient and the formulation aids in the agueous solution of the sulphonic acid salt to produce a homogeneous solution.

Mixtures of two active ingredients Example 6a; Propiconazole 250 g/1 20 Carbendazim 200 g/1 Soprophor FL (ex Rhone Poulenc) 70 g/1 * Silicone antifoam M10 (ex Dow Corning) 5 g/i 60% ammonium cumenesulphonate solution to 100% by volume. Example 6b: 25 Propiconazole 125 g/1 Carbendazim 100 g/1 * Soprophor FL (ex Rhone Poulenc) 50 g/1 Aerosil COK 84 (ex Degussa) 15 g/1 60% ammonium cumenesulphonate solution to 100% by volume.

* Trade Mark All the components of Examples 6a and 6b are blended bydissolving the Propiconazole and Soprophor FL in the ammonium cumenesulphonate solution and then adding the silicone antifoam and the Carbendazim. Once the Carbendazim has been suspended using a suitable mixer, the blend is wet-milled to produce a fine suspension. In the case of Example 6b the thickener, Aerosil COK 84, is dispersed in the formulation after wet-milling by using a high shear mixer.

Example 7; Metalaxyl 80 g/1 copper oxychloride 690 g/1 * Soprophor FL (ex Rhone Poulenc) 30 g/1 * Mowiol 40-88 (ex Hoechst) 10 g/1 60% ammonium cumenesulphonate solution to 100% by volume.

The Metalaxyl, Soprophor FL and Mowiol 40-88 are dissolved in the ammonium sulphonate solution. The copper oxychloride is then suspended in this solution and milled in a suitable wet mill to produce a fine suspension.

Example 8; Metalaxyl 50 g/1 Ziram 200 g/1 *Aerosil COK 84 (ex Degussa) 15 g/1 sodium cumenesulphonate 200 g/1 water to 100% by volume.

Example 8 is produced by dissolving the Metalaxyl in the sodium cumenesulphonate solution in water, and then suspending the Ziram in the solution. After wet-milling the suspension in a suitable mill, the Aerosil COK 84 is dispersed in the formulation by means of a high shear Trade Mark

Claims

1. An aqueous solution concentrate comprising a) a liquid or solid pesticide that is stable in water and less than 1% soluble in water and has a water number 5 greater than 10, and (J) a salt of an aromatic sulphonic acid having the formula R. (I) '3 wherein R lf R 2 and R 3 have the same or different meanings 10 and each is hydrogen or straight-chain or branched C^^-Cgalkyl, Z is a direct bond or a straight-chain or branched C^-Cg-alkylene bridge and R 4 is an alkali metal, an ammonium group, a primary, secondary or tertiary amine group, a hydroxyalkylamine group or a morpholine group, 15 in an amount sufficient to form an aqueous solution.

2. A concentrate according to claim 1, which contains up to 75% w/v of the pesticide as component a and up to 70% w/v of the sulphonic acid of formula I as component β. 20

3. A concentrate according to claim 2, which contains 5 - 50% w/v of the pesticide and 15 - 50% w/v of the sulphonic acid of formula I.

4. A concentrate according to any one of claims 1 to 3, wherein the pesticide is liquid.

5. A concentrate according to any one of claims 1 to 3, wherein the pesticide is solid.

6. A concentrate according to any one of the preceding claims, wherein Z is a direct bond. 5

7. A concentrate according to any one of the preceding claims, wherein Ry, Rj and R 3 have the same or different meanings and each is hydrogen or straight-chain or branched Cy-C 3 -alkyl.

8. A concentrate according to any one of the preceding 10 claims, wherein the compound of formula I is ammonium cumenesulphonate, potassium xylenesulphonate, sodium toluenesulphonate, xylenesulphonic acid or sodium cumenesulphonate.

9. A concentrate according to any one of the preceding 15 claims, wherein a functional aid is added.

10. A concentrate according to claim 9, wherein the functional aid is one or more surfactant(s), a tackifier or thickener or an antifoam.

11. A concentrate according to claim 9, wherein the 20 formulation aid is one or more organic solvent (s).

12. A concentrate according to any one of claims 4 or 6 to 11, wherein the liquid pesticide is Chlorfenvinphos, Metolachlor, Propiconazole or Imazalil.

13. A concentrate according to any one of claims 5 to 25 11, wherein the solid pesticide is 2-(2,4-dichlorophenyl)-1-{1H-1,2,4-triazol-l-yl)-pentane or Metalaxyl.

14. A concentrate according to any one of the preceding claims, wherein there is present, as a further component (T), a solid pesticide not soluble in an aqueous solution of a compound of formula I.

15. A concentrate according to claim 14, wherein component (a) is Propiconazole and component (Y) is Captan or Carbendazim, or component (a) is Metolachlor and component (γ) is Atrazine, or component (a) is Imazalil and component (γ) is Thiabendazole, or component (a) is Metalaxyl or 2-(2,4-dichlorophenyl)-1-(1H-1,2,4triazol-l-yl)-pentane and component (γ) is copper oxychloride, Ziram or Folpet.

16. A process for producing an aqueous solution concentrate as defined in claim 1, comprising dissolving component (a) in an aqueous solution of component ()9).

17. A process for producing an aqueous concentrate as defined in claim 14, comprising producing a solution of component (a) in an aqueous solution of component ()9) and then adding component (γ), and optionally milling the mixture to the desired particle size of the solid components.

18. An aqueous concentrate according to claim 1 substantially as described·, with reference to any of the Examples.

19. A process according to claim 16 of producing an aqueous concentrate substantially as described with reference to any of the Examples .

20. An aqueous concentrate when produced by a process claimed in any of claims 16, 17 or 19.