GB2267826A

GB2267826A - Solvent mixture for plant protection agents

Info

Publication number: GB2267826A
Application number: GB9310524A
Authority: GB
Inventors: Dip-Ing Chem Jacki Muller
Original assignee: STEFES PFLANZENSCHUTZ GmbH
Current assignee: STEFES PFLANZENSCHUTZ GmbH
Priority date: 1992-06-19
Filing date: 1993-05-21
Publication date: 1993-12-22
Anticipated expiration: 2013-05-21
Also published as: DE4220161A1; GB2267826B; GB9310524D0; FR2692438A1; FR2692438B1; DE4220161C2

Abstract

Formulations of active substances for plant protection contain particular aromatics in combination with natural oils as solvent. A surface active agent may be added and the solution emulsified in water.

Description

NEW FORMULATIONS OF ACTIVE SUBSTANCES FOR PLANT PROTECTION AND METHODS FOR

THE USE THEREOF D E S C R 1 P T 1 0 N The present application refers to new formulations of active substances for plant protection containing particular aromatics as solvents in combination with natural oils, and a method for the use thereof.

it is known to dissolve active substances for plant protection in xylenes in the presence of emulsifiers, and, upon practical application of the active substances, to emulsify these solutions in water and to use said active substances in this form. Since, owing to their toxic characteristics, xylenes cannot be regarded as completely safe - they have, for instance, been specified in the 1IEPA. List of Inerts with a high priority for Testing" since 1987 - the plant protection industry has already for some time been searching for suitable substituents for xylenes and other solvents regarded as possibly having toxic effects. Solvents which are comparatively well suited for active substances with hydrophobic character are, for example, the so-called 11SOLVESSO11 solvents, such as the SOLVESS0 types 100, 150 and 200 (leaflet of Exxon Chemichal "Performance Fluids for Pesticides"; SOLVESSO is a registered trademark of Exxon Corporation), the SOLVESSO type 100 being of little interest due to its low flash point of below 600C and its low density.

2 SOLVESSO solvents are mixtures of aromatics which boil at a higher temperature than xylene isomers or mixtures thereof. The indexes 100, 150 and 200 indicate decreasing volatility and increasing flash point. These solvents are able to dissolve relatively large amounts of a great number of active substances.

Owing to the high toxicity especially of pyrethroids, the practical application thereof requires that less con-. centrated solutions be available in order to avoid putting humans and animals at risk. whereas commonly used plant protectives are available on the market as concentrates of more than 700 g per litre, in the case of pyrethroids such concentrations should be avoided by all means. Moreover, these usual, high concentrations are not necessary, due to the small amounts to be used per hectar. For example, only 5g of the pyrethroid deltamethrine and circa 25g of the pyrethroid fenvalerate are applied per hectare. For the above reasons, pyrethroid concentrates mostly only contain 2.5 to 10%-wt of active substance in the concentrate, i.e. 25 to 100 g per litre. it was thus the object of the present invention to develop concentrates which can be precisely adjusted to concentrations which are unproblematic and safe in handling, while improving characteristics such as toxicity, flammability, stability of the aqueous emulsion, biological effect and other characteristics. With the instant application, the applicant has succeeded in developping a solution of active substances, especially of pyrethroids, for plant protection having these improved characteristics, characterized in that the active substance/substances is/are dissolved in a mixture of solvents containing aromatics in the boiling range above the boiling range of xylenes up to a boiling point of 3000C, and veget- able andlor animal oil, and further a method for the use of an active substance emulsion in water for plant protection purposes, characterized in that the active substance is dissolved in solvents containing aromatics in the boiling range above the boiling range of xylenes up to a boiling point of 3000C, and vegetable and/or animal oil, whereby, in addition, at least one surface active agent is added to the solution, the solution is emulsified in water and the emulsion is utilized for plant protection.

Preferred active agents according to the invention are pyrethroids, such as for example permethrin, cypermethrin, deltamethrin or fenvalerate.

of particular significance in this connection are solutions of deltamethrin ((S)-(x-cyano-3-phenoxybenzyl-(1R,3R)-3(2,2-dibromovinyl)-2, 2-dimethylcyclopropanecarboxylate) and fenvalerate ((RS)-a-cyano-3phenoxybenzyl-(RS)-2-(4-chlorophenyl-3-)methyl butyrate). As solvent mixture according to the invention, aromatics are used, in mixture with vegetable and/or animal oil. Suitable aromatics are those in the boiling range above the boiling range of xylenes, i.e. of the individual isomers or mixtures thereof, up to a boiling point of 3000C. Preferred aromatics are those consisting of carbon and hydrogen, namely alkyl benzene, whereby 11alkyll, can be one or more methyl, ethyl, propyl, isopropyl or C,-C, alkyl groups. Such aromatics exhibit comparatively low volatility and flammability and are toxicologically and ecotoxicologically safe. If one defines the evaporation speed of n-butyl acetate with 100, the evaporation speeds of the aromatics according to the invention are about 1 to about 25. These aromatics have in part already been approved by the EPA, as individual compounds or in mixtures. According to the invention the aromatics may be utilized individually or in any mixtures whatever. Solvents of this kind have a very high dissolving capacity for numerous plant protective agents, especially for the above- mentioned pyrethroids. Aromatic solvents are low-priced industrial chemicals which can also be used for the production of active substance solutions of relatively high concentration, so that they can be economically stored and transported. Positive features in this connection are their comparatively low volatility and the comparatively high flash point. Solvents available on the market and well suited according to the invention are the above-described SOLVESSO solvents. The applicant has surprisingly found that vegetable andlor animal oil are particularly suitable for adjusting formulations of dissolved active substances in mixture with these aromatics such as are required for practical application, whereby a great number of the properties of the solutions could be considerably improved over the prior art. Suitable natural oils are both vegetable oils and animal oils, animal oils being preferred. Examples are: rape oil, soya oil, sunflower oil, thistle oil, castor oil, whale oil, fish oil, etc. According to the invention, preferred oils are rape oil, soya oil, sunflower oil and maize oil. The ratio of aromatics to natural oils is <100-40 parts by weight to >0-60 parts by weight. Accordingly, up to 60 parts by weight of aromatics can be replaced by readily biodegradable natural oils, which are in addition absolutely safe with regard to toxicity. The preferred ratio of aromatics to natural oils is 20-80 to 80-20 parts by weight.

The amount of active substance contained in such a solution can be 10-350 g per litre, depending on the active substance. For example, according to the invention, 1 to 100 g per litre, peferably 15 to 75 g per litre and particularly preferred 20 to 60 g per litre, of the pyrethroid deltamethrin are used, or 10 to 350 g per litre, preferably 30 to 320 g per litre and particularly preferred 80 to 240 g per litre, of the pyrethroid fenvalerate. In addition, at least one surface active agent is added to the solution. it has. proved advantageous to use surface active agents which consist of a non-ionic and an anionic component. A particularly suitable nonionic component is nonylphenol, the nonyl group being a propylenetrimer isomer, which is condensed with 4 to 70 moles of ethylene oxide, preferably 30 to 70 moles of ethylene oxide, in mixture with at least one blockpolymer of polyoxypropylene oxide and polyoxyethylene oxide with an average molecular weight of from 1800 to 9000. Ca-dodecylbenzene sulfate has proved a particularly suitable anionic component.

The present invention is, however, not limited to these components. Rather, the man skilled in the art may select further suitable additives from a multitude of known surface active agents. The ratio of anionic to non-ionic components is 1:0.1 to 1:20, preferably 1:1 to 1:5, whereas the ratio of the surface active agent to the active substance is (0.1-5):l.

The formulations according to the present invention offer the advantage that, given an amount of active substance and an amount of surface active agent, the density of the solution can be adjusted to almost exactly 1 kg/1 through variation of the portions of aromatics and natural oils. Using water likewise having a density of 1 kg/1, in this way a very good stability of the spray is achieved. Furthermore, with the formulations according to the present invention the critical classifications according to the German atatutory order on combustible liquids do not apply, since the flash point of the formulations is above the critical value for storage of 550C. Accordingly, the safety requirements for storage of products with a flash point of smaller than or equal to 550C are inapplicable. At the same time, the approved storage amounts increase. Even in the production of double-concentrated preparations, there is no negative effect on the classification according to the German statutory order on dangerous substances, due to the non-toxic oils.

Moreover, by utilyzing natural oils, volatility and thus emission to the environment is reduced. At the same time, the voletilization tendency of the active substance is also reduced and enhanced active substance absorption is achieved.

A further essential advantage of the formulations according to the invention is that they can be packed in watersoluble polyvinyl alcohol films. This is of great importance in view of the obligation to take back empty packings. The solutions according to the present invention thus permit the production of active substance concentrates of high concentration in aromatic solvents which require only little storage room. Furthermore, with water, particularly stable emulsions are obtained wherein no precipitation occurs by precipitating solid matter and which are excellently suited for processing, owing to their density, which corresponds to that of water.

When applying the solutions according to the invention, the active substance/substances is/are therefore preferably dissolved in the aromatic solvent, which permits high concentrations. The solution is then emulsified in water and the emulsion is utilized as a plant protective, for example for the destruction of insect pests.

Some formulations according to the present invention are illustrated by means of the following examples.

Example 1:

Deltamethrin technical grade (98%) 51 g/1 Subst. nonylphenol/blockpolymer + Ca-D. 120 g/1 Solvesso 200 400 g/1 Rape oil ad 1 1 Example 2:

Deltamethrin technical grade 51 g/1 Subst. nonylphenol/blockpolymer + Ca-D. 100 g/1 Mixture of C,_methyl aromatics 350 gIl Soya oil ad 1 1 Example 3:

Fenvalerate technical grade (96%) 209 g/1 Subst. nonylphenol/blockpolymer + Ca-D. 125 g/1 Solvesso 150/Solvesso 200 1:1 324 g/1 Soya oil ad 1 1 Example 4:

Fenvalerate technical grade 220 g11 Nonylphenol/blockpolymer + Mg-D. 120 g/1 Trimethyl benzenelisopropyl benzene 1:1 150 g/1 Sunflower oil ad 1 1

Claims

P A T E N T C L A I M S

1. Active substance solution for plant protection, characterized in that the active substance/substances islare dissolved in a mixture of solvents, which mixture contains aromatics in the boiling range above the boiling range of xylenes up to a boiling point of 3000C and vegetable and/or animal oil.

2. The solution according to claim 1, characterized in that the active substance/substances islare a pyrethroidlipyrethroids.

31. The solution according to claims 1 and 2, characterized in that the ratio of aromatics to oil is <100-40 parts by weight to >0-60 parts by weight.

4. The solution according to the claims 1 to 3, characterized in that the ratio of aromatics to oil is 20-80 parts by weight to 80-20 parts by weight.

5. The solution according to the claims 1 to 4, characterized in that 1 to 100 g per litre, preferably 15 to 75 g per litre, and especially preferred 20 to 60 g per litre, of the pyrethroid deltamethrin are contained in the solution.

6. The solution according to the claims 1 to 4, characterized in that 10 to 350 g per litre, preferably 30 to 320 g per litre, and especially preferred 80 to 240 g per litre, of the pyrethroid fenvalerate are contained in the solution.

7. The solution according to the claims 1 to 6, characterized in that the oil is rape oil.

8. The solution according to claims 1 to 6, characterized in that the oil is soy oil.

9. The solution according to claims 1 to 6, characterized in that the oil is sunflower oil.

10. The solution according to the claims 1 to 9, charaaterized in that the aromatics consist of at least one SOLVESSO solvent (a trademark of Exxon Corporation).

11. The solution according to claims 1 to 10, characterized in that the aromatics consist of carbon and hydrogen.

12. The solution according to claims 1 to 11, characterized in that the solution, in addition, contains at least one surface active agent.

13. The solution according to claims 1 to 12, characterized in that the surface active agent consists of a non-ionic and an anionic component.

14. The solution according to claims 1 to 13, characterized in that as non-ionic component nonylphenol which is condensed with 4 to 70 moles of ethylene oxide, in mixture with at least one blockpolymer of polyoxypropylene and polyoxyethylene having an average molecular weight of from 1800 up to 9000 is used.

15. The solution according to the claims 1 to 14, characterized in that as anionic components Ca-dodecylbenzene sulfonate is used.

16. The solution according to the claims 1 to 15, characterized in that the ratio of the anionic to the non-ionic component is 1:0.1 up to 1:20, preferably 1:1 up to 1:5.

17. The solution according to the claims 1 to 16, characterized in that the ratio of surface active agent to active substance is (0,1-5):l.

18. method for the use of an active substance emulsion for plant protection, characterized in that the active subn. stance is dissolved in solvents containing aromatics in a boiling range above the boiling range of xylenes up to a boiling point of 3000C and vegetable andior animal oil, whereby, in addition, at least one surface active agent is added to the solution, this solution is emulsified in water and the solution is used for plant protection.

19. The method according to claim 18, characterized in that as active substance/substances a pyrethroidlpyrethroids are used.

20. The method according to the claims 18 and 19, characterized in that aromatics and oil are used in a ratio of <l0040 parts by weight to >0-60 parts by weight.

21. The method according to claims 18 to 20, characterized in that the ratio of aromatics to oil is 20-80 parts by weight to 80-20 parts by weight.

22. The method according to claims 18-21, characterized in that 1-100 g per litre, preferably 15-75 g per litre, and especially preferred 20-60 g per litre, of the pyrethroid deltamethrin are used.

23. The method according to claims 18 to 21, characterized in that 10-350 g per litre, preferably 30-320 g per litre, and especially preferred 80240 g per litre, of the pyre- throid fenvalerate are used.

24. The method according to claims 18 to 23, characterized in that as natural vegetable oil rape oil is used.

25. The method according to claims 18 to 23, characterized in that as natural vegetable oil sunflower oil or maize oil is used.

26. The method according to claims 18 to 23, characterized in that as natural vegetable oil soy oil is used.

27. The method according to claims 18 to 26, characterized in that aromatics consisting of at least one SOLVESSO solvent (a trademark of E=on Corporation) is used.

28. The method according to claims 18 to 27, characterized in that aromatics are used which consist of carbon and hydrogen.

29. The method according to claims 18 to 28, characterized in that a surface active agent is used consisting of a nonionic and an anionic component.

30. The method according to claims 18 to 29, characterized in that as nonionic components nonylphenol condensed with 4-70 moles of ethylene oxide is used in mixture with a blockpolymer consisting of polyoxypropylene and polyoxyethylene with an average molecular weight of 1800-9000.

31. The method according to claims 18 to 30, characterized in that as anionic components Ca-dodecylbenzene sulfonate is used.

32. The method according to claims 18 to 31, characterized in that the anionic and non-ionic components are used in a ratio of 1:0.1 to 1:20, preferably 1:1 to 1:5.

33. The method according to claims 18 to 32, characterized in that the ratio of surface active agent and active substance is (0.1 to 5):l.

34. The use of an active substance solution for plant protection according to claims 1 to 17.

35. Active substance solution for plant protection, substantially as hereinbefore described with reference to any one of examples 1 to 4.

36. Use of an active substance solution as claimed in claim 35, for protection of plants.