WO2011080207A1

WO2011080207A1 - The use of a phosphated 2-propylheptanol ethoxylate as a bioefficacy enhancer, and a composition containing the phosphated 2-propylheptanol ethoxylate

Info

Publication number: WO2011080207A1
Application number: PCT/EP2010/070623
Authority: WO
Inventors: Karin BERGSTRÖM
Original assignee: Akzo Nobel Chemicals International BV
Current assignee: Nouryon Chemicals International BV
Priority date: 2009-12-30
Filing date: 2010-12-23
Publication date: 2011-07-07
Anticipated expiration: 2012-06-30

Abstract

The present invention provides a phosphated 2-propylheptanol ethoxylate having 2-10 ethyleneoxy units, for use as an excellent bioefficacy enhancer for a pesticide, preferably a fungicide, in a composition having a conductivity of < 2 mS/cm.

Description

THE USE OF A PHOSPHATED 2-PROPYLHEPTANOL ETHOXYLATE AS A

BIOEFFICACY ENHANCER, AND A COMPOSITION CONTAINING THE

PHOSPHATED 2-PROPYLHEPTANOL ETHOXYLATE

Technical Field of the Invention

The present invention relates to a composition comprising a pesticide and a phosphated 2-propylheptanol ethoxylate. It also relates to the use of the phosphated 2-propylheptanol ethoxylate as a bioefficacy enhancer and a method for treating plants comprising contacting said plant with a composition of the invention. Technical Background

The addition of different surfactants to agricultural compositions may be done for a number of reasons. Often the surfactants are added to obtain a stable formulation that may eventually be combined with water before the application of the formulation onto an agricultural substrate. It is also well known that the uptake as well as the efficacy of many pesticides and fertilisers can be improved by the addition of so called adjuvants. A variety of surfactants, also including phosphate esters, have been used for these different purposes.

In GB 2 049 427 agricultural formulations, which are stable emulsifiable concentrates, comprising alkoxylated phosphates and a biologically active compound, such as a herbicide, are described. The alkoxylated phosphates are phosphate esters of ethoxylated mono-, di- and trialkyl phenols or ethoxylated C_8-2o aliphatic alcohols. In the examples phosphated nonyl phenol ethoxylates or phosphated dinonyl phenol ethoxylates were used.

In US 4 975 1 10 an environmentally compatible herbicidal composition comprising a fatty acid component and a surfactant component, which may be an ethoxylated phosphate ester, is described. The concentrated formulation may be stored as a concentrate, and when it is ready for use it is agitated and diluted with water. In the examples ethoxylated nonyl phenol phosphate is used.

In US 6 432 884 compositions useful as adjuvants for agricultural chemical formulations comprising a lower alkanol ester of a fatty acid and an emulsifier package are described. The emulsifier package comprises a non-ionic surfactant and an anionic surfactant, which may be an ethoxylated partial phosphate ester. These compositions are claimed to have particularly good electrolyte tolerance and are stable to hard water and/or when used in combination with fertilizers. A preferred ethoxylated partial phosphate ester is phosphoric acid partially esterified with nonyl phenol that has been ethoxylated with 9 moles of ethylene oxide.

US 2007/0275854 relates to agrochemical compositions comprising one or more substances selected from pesticides, preferably herbicides, and phytohormones, and one or more substances selected from alkyl phosphoric esters and alkylaryl phosphoric esters, wherein the phosphoric esters comprise one or more branched alkyl groups and in a preferred embodiment are ethoxylated. These agrochemical compositions are claimed to show a significant increase in the activity of the pesticides, an improved compatibility of ingredients, an increased solubility of the pesticides and further ingredients, and they are stable even when highly stressed. The most preferred phosphate esters are isotridecyl phosphoric esters optionally comprising ethylene oxide units and tri-sec-butylphenol phosphoric esters optionally comprising ethylene oxide units. All examples are performed with herbicides.

WO 2006/019772 relates to the use of phosphated 2-propylheptanol, phosphated 2- propylheptanol alkoxylate and/or mixtures thereof in agricultural formulations as dispersants, emulsifiers, hydrotrope, wetting agents and compatibility agents. All examples relate to the use of the above-mentioned products as hydrotropes and compatibility agents in solutions comprising a high amount of electrolytes.

High amounts of electrolytes are usually added as fertilizers to enhance growth. To minimize work load, farmers prefer to mix fertilizers and one or more pesticide and spray at the same time. Pesticides can also be delivered in combinations with fertilizers for this reason.

It is well known that the efficacy of a fungicide treatment is dependent on the disease stage of the fungi infection. It is preferable to treat the crop as soon as the disease is established, most preferably within the first few days after the infection. The first visible sign of many fungi infections is yellowing of the leaves. In e.g. Septoria tritici infection, this yellowing appears approximately 6 days after infection (depending on humidity and temperature). More significant signs, such as groups of black spores from the fungi (pycnidias) on the upper leaves, become visible approximately 10 days after infection. Treatment at that point in time is too late since all existing fungicides on the market exhibit a dramatically reduced efficacy with the number of days past infection. Thus, today the farmer has to rely on temperature/humidity based national warning programs and spray in a preventive manner, causing extra cost and environmental pressure. Further, during bad weather conditions that prevents spraying, the farmer might miss the treatment window.

Hence, there is in general a need for improved adjuvants that can enhance the bioefficacy of the pesticide, especially adjuvants that can prolong the treatment window for fungi infections.

Summary of the Invention

It is an object of the present invention to provide adjuvants, which can enhance the bioefficacy of a pesticide, and which can prolong the treatment window for fungi infections.

The present inventor has surprisingly found that this objects can be met by utilizing a phosphated 2-propylheptanol ethoxylate having 2-10 ethyleneoxy units, as such a compound has a bioefficacy enhancing effect on pesticides. Especially, the present inventor surprisingly found that the phosphated 2-propylheptanol ethoxylate exhibited this bioefficacy enhancing effect on pesticides in compositions exhibiting a conductivity of < 2 mS/cm.

An advantage of the present invention is the possibility to prolong the treatment window for fungi infections

The current invention expands the treatment window to at least 8 days after infection and gives the farmer more flexibility and an opportunity to wait until signs of the disease are established.

A high amount of electrolytes, such as fertilizers, was in some circumstances shown to have a negative impact on uptake of the pesticide or on crop safety. Also, the higher the electrolyte content, the smaller the amount of pesticide was possible to dissolve in a specific formulation. A suitable indicator for the electrolyte content of a formulation is its conductivity.

Hence, in a first aspect, the present invention relates to a composition comprising a pesticide and a phosphated 2-propylheptanol ethoxylate having 2-10 ethyleneoxy units, and where the composition exhibits a conductivity of < 2 mS/cm.

In a second aspect, the present invention relates to the use of a phosphated 2- propylheptanol ethoxylate having 2-10 ethyleneoxy units as a bioefficacy enhancer for a composition comprising a pesticide in a composition having a conductivity of < 2 mS/cm. In a third aspect, the present invention relates to a method for the treatment of a plant, comprising contacting said plant with a composition of the present invention.

These and other aspects of the invention will now be described more in detail.

Description of the Invention

The present invention relates in general to a phosphated 2-propylheptanol ethoxylate having 2-10, preferably 2-7, more preferably 2-5 and most preferably 5, ethyleneoxy units. This compound works as a bioefficacy enhancer for a pesticide, preferably a fungicide, in an agricultural composition having a conductivity of < 2, preferably <1 mS/cm.

A composition of the present invention comprises a pesticide and a phosphated 2- propylheptanol ethoxylate having 2-10, preferably 2-7, more preferably 2-5 and most preferably 5, ethyleneoxy units, and has a conductivity of < 2, preferably <1 mS/cm.

In the context of the present invention, conductivity is measured in accordance with ASTM D-1 125 "Standard test methods for electrical conductivity and resistivity of water".

In a composition of the present invention, the phosphated 2-propylheptanol ethoxylate has the function of a bioefficacy enhancer, i.e. the phosphated 2- propylheptanol ethoxylate increases the bioefficacy of the pesticide.

There is an especially good effect for triazole fungicides.

Examples of triazole fungicides that may be used in the agricultural compositions of the invention are amisulbrom, bitertanol, fluotrimazole, triazbutil, azaconazole, bromuconazole, cyproconazole, diclobutrazol, difenoconazole, diniconazole, diniconazole-M, epoxiconazole, etaconazole, fenbuconazole, fluquinconazole, flusilazole, flutriafol, furconazole, furconazole-cis, hexaconazole, imibenconazole, ipconazole, metconazole, myclobutanil, penconazole, propiconazole, prothioconazole, quinconazole, simeconazole, tebuconazole, tetraconazole, triadimefon, triadimenol, triticonazole, uniconazole and uniconazole-P.

In particular, tebuconazole and prothioconazole are preferred.

The amount of the phosphated 2-propylheptanol ethoxylate in a concentrated composition is typically within the range 5-15 % by weight. This concentrated composition is preferably diluted before use, typically with water. The active amount of the phosphated 2-propylheptanol ethoxylate in a ready-to-use composition is suitably at least 0.015, preferably at least 0.1 % by weight; and suitably at most 3.0, preferably at most 1.0, more preferably at most 0.5 and most preferably at most 0.25 % by weight.

It is to be noted that compositions of the present invention may comprise multiple pesticides.

The phosphated 2-propylheptanol ethoxylate could also be tank mixed, i.e. mixed in the spray tank with the other ingredients of the composition at the time of spray application.

Additional components that may be added to the composition of the invention include pH-adjusting agents; sticking agents or deposition enhancers, such as polymers; foam enhancers; other adjuvants such as wetting agents, oils and compatibility agents; crystallization inhibitors; humectants, such as glycerol or polyethylene glycols; plant growth regulators; and water and other solvents.

The concentrated compositions of the present invention are preferably liquid and may be a suspension concentrate, a suspoemulsion, an oil dispersion, an emulsifiable concentrate, an emulsion or a water soluble liquid.

The water diluted ready-to-use compositions may be emulsions, suspensions, or clear solutions.

In the compositions of the present invention the weight ratio of the pesticide to the phosphated 2-propylheptanol ethoxylate is at most 70:1 , preferably at most 60:1 , more preferably at most 50:1 , even more preferably at most 40:1 , still more preferably at most 30:1 , still more preferably at most 25:1 , still more preferably at most 20:1 , still more preferably at most 10:1 , still more preferably at most 2:1 and most preferably at most 1 :1 ; and is at least 1 :20, preferably at least 1 :10, even more preferably at least 1 :5, and most preferably at least 1 :2. Normally the weight ratio ranges between 20:1 to 1 :20, suitably 2:1 to 1 :10, such as 1 :1 to 1 :5. The pH of the compositions is preferably equal to or less than 7.

The present invention also relates to the use of a phosphated 2-propylheptanol ethoxylate comprising 2-10, suitably 2-7, preferably 2-5, and most preferably 5, ethyleneoxy units as a bioefficacy enhancer for a pesticide, preferably a fungicide, more preferably a triazole fungicide and most preferably tebuconazole or prothioconazole, in a composition having a conductivity of < 2, preferably < 1 mS/cm.

The present invention also relates to a method for the treatment of a plant, comprising contacting a plant with a composition of the present invention. Preferably, in such method, the composition is distributed by means of spraying. The composition of the present invention provides an prolonged treatment window for fungi infections, such as Septoria tritici, and treatment is effective even if the first treatment of an infected plant is performed at least 7, such as at least 8 days after the infection.

The phosphated 2-propylheptanol ethoxylate utilized in all aspects of the present invention on average comprises 2-10, suitably 2-7, preferably 2-5, and most preferably 5, ethyleneoxy units. In one embodiment, the bioefficacy enhancer of the invention comprises at least one phosphated alkoxylate according to the formula

OM

H₃C-(-CH₂-^CH-CH₂-0-f CH₂-CH₂-O -OM (II)

C₃H₇ O where M is H, a monovalent metal ion or R-|R₂R₃R₄N⁺, where R-i , R₂, R₃, and R₄ are H, an alkyl group with 1 -4 carbon atoms or -CH2CH2OH, and c is a number 2-10, preferably 2-7, more preferably 2-5, and most preferably 5.

A phosphated 2-propylheptanol ethoxylate may be obtained by different processes, the most common being the reaction of ethoxylated 2-propylheptanol with polyphosphoric acid or phosphorous pentoxide (P2O₅). Herein, all numbers of ethyleneoxy units given for the products refer to the molar amount of ethylene oxide added to one mole of starting alcohol.

In the process using polyphosphoric acid the resulting product mixture will predominantly contain the monoalkylphosphate ester of ethoxylated 2-propylheptanol and only a small amount (<10% by weight) of the dialkylphosphate ester. Always rather large amounts of inorganic phosphate residues from the polyphosphoric acid, such as orthophosphoric acid, will be present.

When P₂0₅ is used as the phosphatising reagent and the molar ratio between P₂0₅ and ethoxylated alcohol is 1 :3, the product mixture will contain about equal amounts of monoalkylphosphate ester and dialkylphosphate ester, and only smaller amounts of inorganic phosphate residues. A larger amount of ethoxylated alcohol will yield more diester, and a smaller amount will yield more monoester. It will be known to a person skilled in the art how to synthesise phosphate esters with certain amounts of mono- and dialkyl phosphate esters. For a general description of phosphate esters see, e.g., Anionic Surfactants Vol. 7, Part II, pages 504-51 1 in Surfactant Science Series, edited by Warner M. Linfield, Marcel Dekker Inc., New York and Basle 1976. The alcohol ethoxylates to be phosphated may be either of the standard type produced by using an alkaline catalyst such as KOH, or of the narrow range type produced by using a narrow range catalyst, such as an acid catalyst, Ca(OH)₂ or hydrotalcite.

If necessary, the reaction mixture resulting from either of the procedures can be neutralized by an organic or inorganic base before use. The base may be, e.g., an alkali hydroxide, such as sodium hydroxide or potassium hydroxide; ammonia, an alkanolamine, such as monoethanolamine, triethanolamine or methyldiethanolamine; or an alkylamine such as triethylamine.

The product mixture resulting from the reaction of ethoxylated 2-propylheptanol with polyphosphoric acid may also contain smaller amounts of products containing more than one phosphate unit according to the formula

OM

H₃Ci_:CH₂- CH-CH₂(0-CH₂-CH₂^ O-P^_nO-M (III)

C₃H₇ O where n is 2-3 and M and c have the same meaning as above.

For ethoxylates containing smaller amounts of ethyleneoxy units, also a certain amount of unethoxylated product will remain due to the distribution of ethyleneoxy units. This unethoxylated product will also be phosphatised during the reaction with the phosphatising agent, and thus the phosphate ester of 2-propylheptanol will also be present in the reaction mixture resulting from these above-mentioned ethoxylates.

The dialkylphosphate ester of ethoxylated 2-propylheptanol has the formula

H₃C CH₂-¾- CH₃ (IV)

where M and c have the same meaning as above.

The product mixture resulting from the reaction of ethoxylated 2-propylheptanol with P₂0₅ may also contain a dialkyl diphosphate ester according to the formula

where M and c have the same meaning as above. This type of diester may be hydrolysed to yield 2 moles of monoester.

2-Propylheptanol is normally made by a process resulting in small amounts of byproducts such as 4-methyl-2-propylhexanol and 5-methyl-2-propylhexanol. These products or their ethoxylates will also be phosphated during the process, and the phosphated species will be comprised in the resulting product mixture.

The product mixture will often also contain < 10% by weight of alcohol and/or alcohol ethoxylate that has not been phosphated in the phosphatation process.

The reaction mixtures obtained by the phosphatising procedures are normally used as such without any purification procedure, but both the mixtures and the purified phosphate esters function as bioefficacy enhancers.

Preferably more than 60, more preferably more than 70, and most preferably more than 80% by weight of the mixture should be monoalkyl phosphate esters.

The present invention is further illustrated by the following examples. Example 1 . Enhanced Bioefficacy

Field experiments were performed with winter wheat (variety Ritmo). The winter wheat was treated with two different fungicides 6 days after infection (dpi) by Septoria tritici. The application rate of tebuconazole and prothioconazole was 75% of the recommended dose/ha. This corresponds to 188 g ai/ha (active ingredient/hectare) for tebuconazole and 94 g ai/ha for prothioconazole. 0.1 and 0.25 % by weight respectively of the phosphated 2-propylheptanol ethoxylate was added to the fungicide into the spray solution. The wheat plants were sprayed with a System2 sprayer from Schachtner, Germany. One treatment was done without any bioefficacy enhancer present. The disease severity was judged by counting the number of pycnidias on the F-F4 leaves and the treatment was performed in growth stage 55 (defined by Zadoks et al, Weed research, 1974).

Table 1

Prothioconazole 30 13.9

Prothioconazole + 0.1 % 2PH-5EO-Phosphate 22 14.4

Prothioconazole + 0.25% 2PH-5EO-Phosphate 23 14.5

¹ 2PH-5EO-Phosphate = 2-propylheptanol that has been ethoxylated with 5 moles of ethylene oxide and phosphated by P2O₅.

Example 2. Prolonged treatment window

Field experiments were performed with winter wheat (variety Ritmo). The winter wheat was treated 3 or 8 days after Septoria tritici infection (dpi) with two different application rates of tebuconazole, 75% and 37% respectively of the recommended dose/ha, which corresponds to 188 g ai/ha and 94 g ai/ha. 0.05, 0.1 and 0.25 % by weight of the phosphated 2-propylheptanol ethoxylate was added to the spray solution in the 37% fungicide treatment. One treatment was done without any phosphated 2-propylheptanol ethoxylate present. The disease severity was judged by counting the number of pycnidias on the F-F4 leaves. The treatment was performed in growth stage 55.

Table 2

Example 3. Conductivity in spray solution

The conductivity of different spray solutions were measured according to ASTM D- 1 125 using a HI8733 conductivity meter from Hanna, Italy. The measurements were performed at room temperature.

The atrazin and tebuconazole formulations in table 3 are formulated as commercial suspension concentrates. The 2PH-5EO-Phosphate was added to the tebuconazole formulations as an in-can bioefficacy enhancer at two different concentrations. These samples were diluted 100 times in tap water as this represents the highest concentration used in the spray tank.

UAN 28% is used as a fertilizer, normally sprayed onto the crop without any further dilution, but could also be mixed with crop protection formulations. The conductivity of this solution is measured for comparison reasons to show the level when fertilizer is present.

2PH-5EO phosphate was diluted 100 and 1000 times, respectively, in tap water. This represents a normal usage level as tank-mix bioefficacy enhancer.

Table 3

¹ UAN 28% = Solution of 30% urea and 40% ammonium nitrate in tap water.

Claims

1 . A composition comprising a pesticide and a phosphated 2-propylheptanol ethoxylate having 2-10 ethyleneoxy units, and where the composition exhibits a conductivity of < 2 mS/cm.

2. A composition according to claim 1 , where the phosphated 2-propylheptanol ethoxylate has 2-7 ethyleneoxy units.

3. A composition according to claim 2, where the phosphated 2-propylheptanol ethoxylate has 2-5 ethyleneoxy units.

4. A composition according to any one of the preceding claims, where the phosphated 2-propylheptanol ethoxylate is produced by reacting a 2- propylheptanol ethoxylate having 2-10 ethyleneoxy units with polyphosphoric acid or phosphorous pentoxide.

5. A composition according to any one of the preceding claims, where the pesticide is a fungicide.

6. A composition according to claim 5, where the fungicide is a triazole.

7. A composition according to claim 6, where the fungicide is selected from the group consisting of tebuconazole and prothioconazole.

8. A composition according to any one of the preceding claims, where the active of amount of the phosphated 2-propylheptanol ethoxylate is within the range 0.015 - 3.0% by weight.

9. A composition according to any one of the preceding claims, where the active of amount of the phosphated 2-propylheptanol ethoxylate is within the range 0.015 - 0.5% by weight.

10. A composition according to any one of the preceding claims, where the active of amount of the phosphated 2-propylheptanol ethoxylate is within the range 0.1 - 0.25% by weight.

1 1 . A composition according to any one of the preceding claims, where the weight ratio of the pesticide to phosphated 2-propylheptanol ethoxylate is 70:1 to 1 :10.

12. Use of a phosphated 2-propylheptanol ethoxylate having 2-10 ethyleneoxy units as a bioefficacy enhancer for a pesticide in a composition having a conductivity of < 2 mS/cm.

13. Use according to claim 12, wherein said pesticide is a fungicide.

14. Use according to claim 13, wherein said fungicide is selected from the group consisting of tebuconazole and prothioconazole.

15. Method for the treatment of a plant, comprising contacting said plant with a composition according to any one of the claims 1 -1 1 .