Novel suspoemulsions of active ingredients for plant protection

Abstract

The invention relates to plant-protection agents which contain one or more active ingredients and which are based on suspoemulsions containing aqueous and organic phases, where the organic phase contains one or more surfactants from the group comprising the ethylene oxide/propylene oxide block polymers having an average molecular weight of 1,000-20,000. The suspoemulsions are subjected to large shear forces. Even thereafter, they exhibit a constant viscosity behavior, in spite of a large number of droplets and a low droplet size.

Description

In general, suspoemulsions are taken to mean formulations having at least three different phases, an aqueous, an organic and a solid phase. It is possible for water to function as an excipient phase in which one or more active ingredients are finely dispersed as the solid phase; the third phase in the suspoemulsion is then an organic solvent phase in which one or more active ingredients are present in emulsified form (EP-A 117,999 and EP-A 142,485). In principle, water-soluble active ingredients may also be dissolved in the aqueous phase.

The formulations described in EP-A 117,999 are storage-stable and applicationally ideal; however, under the action of large shear forces over a relatively long period of time, they may develop a very fine droplet distribution, which can lead to high viscosities of the finished formulation. In addition, there are certain active ingredient combinations of a relatively novel type which can be prepared by the process described therein only with limitations.

In EP-A 142,485, it is expressly pointed out that crystal formation can occur in the organic phase and that storage stability is only ensured for 1 month at elevated temperature. The object was therefore to develop novel suspoemulsions having improved applicational properties.

Surprisingly, it has now been found that suspoemulsions which contain one or, above all, several active ingredients and whose organic phase contains ethylene oxide/propylene oxide block polymers or ethoxylated polyarylphenol compounds as surfactants have advantageous properties. Although they contain very small droplets, they remain very highly flowable, do not tend towards crystal formation and are stable on storage. In addition, these suspoemulsions can also be applied in ULV (ultra low volume) form (Winnacker, Kuchler: Chemische Technologie [Chemical Technology], vol. 7, Org. Techn. III, Carl Hanser Verlag Munich/Vienna (1986) pp. 322 ff.).

The invention therefore relates to plant-protection agents which are based on suspoemulsions containing aqueous and organic phases and which contain one or more active ingredients, wherein the organic phase contains one or more surfactants from the group comprising the ethylene oxide/propylene oxide block polymers having an average molecular weight of 1,000-20,000, such as, for example, HOE S 3510 (Hoechst AG), HOE S 1816 (Hoechst AG) and .RTM.Rewopal PO (Rewo Chemie) or the ethoxylated polyarylphenol compounds or the mono- and/or polyalkylphenol compounds, such as, for example, the .RTM.Arkopal or .RTM.Sapogenat series from Hoechst AG, or mixtures thereof. Ethylene oxide/propylene oxide block polymers which can be used according to the invention are, in particular, the polymers of the formulae I and II below: ##STR1## where, in these formulae, x, y and z, independently of one another, denote a number from 2 to 200 and R denotes H or (C.sub.1 -C.sub.10)alkyl (HOE S 3510 (type I) and HOE S 1816 (type II)). Where R=H, the block polymers may also be phosphated, in particular monophosphated (HOE S 3618, type II). Possible ethoxylated polyarylphenol compounds are preferably tristyryl-substituted phenols containing 5-30 moles of EO.sup.1), such as, for example, HOE S 3474 (Hoechst AG) or .RTM.Soprophor BSU (Rhone Poulenc).

.sup.1) EO=ethylene oxide

In general, the suspoemulsions contain two active ingredients.

Active ingredients employed in the organic phase are: 3,5-dihalo-4-hydroxybenzonitriles and esters and salts thereof, such as bromoxynil octanoat and ioxynil octanoat; substituted phenoxyacetic(propionic) acids and esters, such as mecoprop, 2,4-D ester and MCPA; (hetero)aryloxyphenoxy esters, such as fluazifop, fenoxaprop-ethyl and diclofop-methyl; phosphates, such as pyrazophos; fungicidal triazoles, such as propicanazole; pyrethroids, such as deltamethrin; aniline derivatives, such as pendimethalin, trifluralin, alachlor and metolachlor; imidazolecarboxamides, such as, for example, prochloraz; phenylurea derivatives, such as monolinuron; ethyl [3-(2-chloro-4-trifluoromethylphenoxy)-6-nitrobenzoyloxy]-acetate (RH 8301); N-[3-(1-ethyl-1-methylpropyl)-5-isoxazolyl]-2,6-dimethoxybenzamide (EL 107); [4-amino-3,5-dichloro-6-fluoro-2-pyridinyl]oxyacetic acid esters, in particular the isooctyl ester (fluroxypyr), or phenol derivatives, such as, for example, dinoseb or dinoseb acetate.

Suitable solvents for the organic phase are aromatic hydrocarbons, such as, for example, xylene, toluene and 1/2-methylnaphthalene; mixtures of (C.sub.6 -C.sub.16)-aromatics, such as the .RTM.Solvesso series with types 100, 150 and 200; water-immiscible ketones, such as, for example, isophorone, or substituted aromatics, such as, for example, halogenated aromatics. These solvents may also be admixed with (C.sub.1 -C.sub.12)-phthalic acid esters as solubilizers; the latter may also completely replace the former.

Active ingredients which can be used for the aqueous phase are sulfur, carbendazim, triphenyltin hydroxide (TPTH), endosulfan, triazine derivaties, such as, for example, atrazine, simazine and cyanazine, dithiaanthraquinones, such as dithianon, dioxoimidazolidinecarboxamides, such as, for example, iprodione, pyridazinones, such as, for example, chloridazon, butenoates, such as binapacryl or phenylurea derivatives, such as, for example, linuron, isoproturon, diuron or chlortoluron, or mixtures thereof. These active ingredients are employed as ready formulations containing the conventional formulation auxiliaries, as described, for example, in EP-A 22,925, EP-A 110,174 and German Patent Application P 35 38 247.3.

The aqueous phase can contain the following dispersants: alkali metal salts of sulfosuccinic acid monoesters (prepared by reacting a polyglycol ether of a product of the condensation of (C.sub.8 -C.sub.12)-alkylphenol and formaldehyde with maleic anhydride and an alkali metal sulfite), alkali metal salts of a sulfo group-containing product of the condensation of a phenol and formaldehyde, alkali metal, ammonium or amine salts of partial esters of alkyl polyglycol ether phosphates, alkali metal salts of a lignin sulfonic acid mixed with equal parts of a swellable alkaline-earth metal silicate, salts of polymerized alkylnaphthalenesulfonic acids or salts of ethoxylated alkylphenol novolaks. Furthermore, further conventional formulation auxiliaries, such as wetting agents, for example Na oleoyl N-methyltauride and tridecyl alcohol polyglycol ether, antifoaming agents based on tributyl phosphate or on silicone, antifreeze agents, such as, for example, ethylene glycol, propylene glycol and glycerol, alumosilicates having a leaf structure, such as montmorillonites or bentonites, safeners, such as, for example, urea, and conventional preservatives, such as benzoic acid and sorbitan acid, inter alia, may be added in addition.

The suspoemulsions according to the invention may contain, for example, the following active ingredient combinations: diclofop-methyl/isoproturon, deltamethrin/endosulfan, pyrazophos/sulfur, pendimethalin/chlortoluron, pyrazophos/carbendazim and/or TPTH, prochloraz/carbendazim, trifluralin/triazines (atrazine and simazine) and pyrazophos/dithianon.

The aqueous phase contains 0.1 to 70% by weight of active ingredient, 0.5 to 15% by weight of dispersant, 0.1 to 15% by weight of wetting agent, 0.1 to 5% by weight of antifoaming agent, 1.0 to 15% by weight of antifreeze and 0.01 to 4% by weight of alumosilicates.

In the organic phase, which contains the solvents cited above individually or in mixtures, the active ingredients are present in dissolved form. 0.1 to 90% by weight of active ingredient, 0.1 to 35% by weight of surfactant, but specifically 1.0 to 10.0% by weight, and 2 to 90% by weight of solvent are included.

The aqueous phase to organic phase ratio can vary within broad limits between 100:1 and 1:100, depending on the conditions.

In the case of application as aqueous suspension concentrates, the aqueous, dispersed phase to organic phase ratio is generally between 1:1 and 100:1, but preferably 1:1 to 20:1. In the case of a ULV application, the aqueous phase to organic phase ratio is 1:1 to 1:100, but preferably 2:3 to 1:20. In this case, the organic phase (oil) is then an excipient phase in which the aqueous phase, which contains the active ingredient(s) suspended there in solid form, is present as finely divided droplets.

The aqueous dispersion formulations are prepared in the known fashion by wet-grinding by means of bead, bore, sand or colloid or corundum-disk mills.

The active ingredients and surfactants of the organic phase are dissolved in the solvent with stirring and, if necessary, warming and subsequent cooling.

The aqueous, disperse phase and the organic phase containing the surfactant(s) and active ingredient(s) are subjected, in a known fashion (for example according to EP-A 117,999), to large shear forces, i.e. shear forces from 1-7,000 sec.sup.-1, during which the storage-stable suspoemulsions desired are obtained.

The invention is illustrated by the following examples.

TABLE 1__________________________________________________________________________Formulation examples (component data in % by weight)__________________________________________________________________________ 1 2 3 4 5 6 7 8 9 10 11 12 13__________________________________________________________________________Isoproturon Disp. 40 40 40 67 75 54 37 91 91 72.5 40 48.5Linuron Disp. 31.5Trifluralin 18 18 18 16 18Fluroxypyr 7.2 4 4.6EL 107 1.5RH 8301 1.4Pendimethalin 9 7.5Alachlor 31.2Bromoxynil octanoat 4.6Ioxynil octanoat 4.2Dinoseb (acetate) 38.5Dioctyl phthalate 28 20 3.3 10 25.sup.R Solvesso 100 14.3 5 10.5.sup.R Solvesso 150 28 28 15 26.7 6.6 3.3 5Xylene 24.2Hoe S 3510 4 4 4 2.5 4Hoe S 1816 2.5 1 1 1 2.5HOE S 1816-1 2.5Hoe S 3474 2.5.sup.R Soprophor BUSO 1Water to 100__________________________________________________________________________ 14 15 16 17 18 19 20 21 22 23 24 25__________________________________________________________________________Linuron Disp. 31.5 31.5 31.5 31.5 39.5Sulfur Disp. 70 70 80Carbendazim Disp. 33Endosulfan Disp. 30TPTH Disp. 40 50Pyrazophos 4 4 15 10Deltamethrin 2 3 4Monolinuron 15.6Alachlor 31.2 31.2 31.2Metolachlor 31.2Dioctyl phthalate 12 12 121/2 Methylnaphthalene 30 22 12Xylene 24.2 24.2 24.2 24.2 5 4Isophorone 26.4Hoe S 3510 5.7 2 5 4.5 3.7Hoe S 1816 4HOE S 1816-1 4 4Hoe S 3474 4 2.sup.R Soprophor BSU 4 2Water to 100__________________________________________________________________________ 26 27 28 29 30 31 32 33 34 35 36 37 38__________________________________________________________________________Isoproturon Disp. 30Linuron Disp. 31.6 30 30.5 30.5Carbendazim Disp. 35 50 45 35 10TPTH Disp. 30 10Dithianon Disp. 30Pyrazophos 25Prochloraz 30Monolinuron 5Alachlor 30Metolachlor 30Dioctyl phthalate 60 27 60 27 50 601/2 Methylnaphthalene 63.sup.R Solvesso 200 63 35Xylene 46 50 55 85HOE S 3510 5 4 4 4 4 4 4 4 4Hoe S 1816 2 2 2HOE S 3618 5Water to 100__________________________________________________________________________ 39 40 41 42 43 44 45 46 47 48 49 50 51__________________________________________________________________________Isoproturon Disp. 40 40 40 40 40 40Chlortoluron Disp. 30Sulfur Disp. 30 30Endosulfan Disp. 30 30Atrazine Disp. 30Dithianon 30Pyrazophos 14 5Deltamethrin 1Dichlofop-methyl 10Trifluralin 18 18 10 15Pendimethalin 18 8Dioctyl phthalate 60 55 60 60 60 601/2 Methylnaphthalene 50.sup.R Solvesso 150 33 33 33 33 35Xylene 45HOE S 3510 5 5 2.5 5 2.5 5 5 5 5 5Hoe S 1816 2 5Water to 100__________________________________________________________________________ TABLE 2______________________________________(Comparison examples)Isoproturon: Trifluralin = 200: 200 g/lViscosity [mPa.s] Droplet diameter [.mu.m]112 [rpm] 13 [rpm] 50% 75% 90% Recipe______________________________________I 315 732 12.5 17.5 20.0 According to 348 835 5.0 9.0 27.0 Example 1 343 860 3.4 8.0 16.0 287 570 2.2 4.0 7.0 311 680 2.0 3.5 8.5II 660 1702 5.3 6.6 7.6 According to 648 1686 3.8 4.0 5.5 Example 2 660 1586 2.9 3.7 4.8 592 1442 2.65 2.95 3.6 653 1570 1.95 2.2 2.6 641 1678 1.55 1.95 3.0III 247 702 5.5 14.0 85.0 According to 249 737 3.05 4.7 9.0 Example 3 239 665 2.5 3.7 7.8 233 634 2.0 2.6 3.6IV 434 1058 13.5 15.7 18.5 According to 494 1152 2.95 3.6 4.4 EP-A 117,999, 533 1326 1.85 2.05 2.2 Example 1 549 1431 1.35 1.65 1.85 621 1669 <1 1.55 1.75 668 1814 <1 1.35 1.65______________________________________ As shown by Table 2, the suspoemulsions according to the invention have a constant viscosity behavior, in spite of a large number of droplets and a small droplet size, in contrast to the known suspoemulsions according to EP-A 117,999.

Claims

1. A herbicidal suspoemulsion composition with an aqueous and an organic phase, wherein the aqueous phase comprises 0.1 to 70% by weight of a herbicidally effective amount of active ingredient selected from the group consisting of linuron, isoproturon, diuron, chlortoluron and a mixture thereof, and the organic phase comprises 0.1 to 90% by weight of a herbicidally effective amount of active ingredient selected from the group consisting of trifluralin, pendimethalin and a mixture thereof, 0.1 to 35% by weight of one or more surfactants selected from the group consisting of ethylene oxide/propylene oxide block polymer of the formulae I and II ##STR2## wherein X, Y and Z, independently of one another, denote a number from 2 to 200 and R denotes H or (C.sub.1 -C.sub.10)-alkyl, having an average molecular weight from 1,000 to 20,000 and 2 to 90% by weight of one or more organic solvents selected from the group consisting of aromatic hydrocarbons, mixture of (C.sub.6 -C.sub.16)-aromatics, water-immiscible ketones and halogenated aromatics.

2. A composition as claimed in claim 1, wherein the surfactant is a polymer of the formula II, wherein X and Z have the same meaning.

3. A composition as claimed in claim 1, wherein the organic phase comprises 1.0 to 10% by weight of surfactant.

4. A composition as claimed in claim 1, wherein the aqueous phase active ingredient is isoproturon and the organic phase active ingredient is trifluralin.

5. A composition as claimed in claim 1, wherein the one or more organic solvents are selected from the group consisting of xylene, toluene, 1- and 2-methylnaphthalene, mixture of (C.sub.6 -C.sub.16)-aromatics and isophorone.

6. A composition as claimed in claim 1, wherein the organic solvent is a mixture of (C.sub.6 -C.sub.16)-aromatics.

7. A composition as claimed in claim 1, wherein the surfactant is an ethylene oxide/propylene oxide block polymer of the formula I or II as defined in claim 1.

8. A composition as claimed in claim 7, wherein the aqueous phase active ingredient is isoproturon and the organic phase active ingredient is trifluralin.

9. A composition as claimed in claim 8, wherein the organic solvent is a mixture of (C.sub.6 -C.sub.16)-aromatics.

10. A composition as claimed in claim 1, wherein the aqueous phase to organic phase ratio is between 100:1 to 1:100.

11. A composition as claimed in claim 1, wherein the composition is a suspension concentrate having an aqueous phase to organic phase ratio between 1:1 and 100:1.

12. A composition as claimed in claim 11, wherein the aqueous phase to organic phase ratio is 1:1 to 20:1.

13. A composition as claimed in claim 1, wherein the composition is a ULV-formulation having an aqueous phase to organic phase ratio of from 1:1 to 1:100.

14. A composition as claimed in claim 1, wherein the aqueous phase to organic phase ratio is 2:3 to 1:20.

15. A composition as claimed in claim 1, wherein the aqueous phase additionally comprises 0.1 to 15% by weight of dispersant or wetting agent or 1.0 to 5% by weight of antifoaming agent or 1.0 to 15% by weight of antifreeze or 0.01 to 4% by weight of alumosilicates or a mixture thereof.