Patent Application
20180139963
The present invention relates to insecticidal organophosphate (active) containing liquid compositions which, after dilution with water at the active application dose, do not produce the unpleasant odour due to the presence of organophosphates, or alternatively the odour is very reduced.
More specifically the present invention relates to the use of additives for reducing the odour associated with the field distribution of the agro compositions containing organophosphates as actives.
It is known that organophosphates during field distribution at the application dose develop unpleasant odours. This is a drawback for the users who carry out the field application of said insecticides.
Methods are known in the prior art for reducing the odour of the organophosphate compounds as such, by using a variety of additives.
U.S. Pat. No. 2,879,284 describes a process wherein a dithiophosphate ester is treated with an organic or inorganic peroxide or hydroperoxide. The compounds are admixed by stirring and at the end the odorless dithiophosphate ester is recovered.
U.S. Pat. No. 2,962,521 describes a process wherein a dithiophosphate ester is emulsified in an aqueous solution of an hydroxide or alkaline metal carbonate. After stirring and subsequent stratification of the liquid phases, the oily layer is separated, washed and dried, obtaining the colourless and odorless dithiophosphate ester compound.
By these prior art methods, as said, the odour from the active compounds as such can be removed. These methods cannot be applied to organophosphate formulations when diluted for field application. In practice according to the teaching of these patents it is necessary to purify the organophosphate active before it is formulated in a composition.
This represents a drawback from an industrial point of view, as in the plant for the production of the active, it is necessary to arrange an unit for purifying the product obtained by synthesis.
In U.S. Pat. No. 3,714,301 the odour of the organophosphate compounds is reduced by treatment with a compound containing nitrogen selected from nitrogen oxide (NO), N2O3, organic or inorganic nitrites. The treatment can be carried out by contacting under stirring these nitrogen-containing compounds with the organophosphate compound in the liquid state.
Also this patent, as those previously cited, describes a purification process carried out on the organophosphate compound. Therefore also the method of this patent is not applicable to reduce the odour of the formulations containing organophosphate compounds not purified before the preparation of the formulation. In the background of the patent it is also reported that the organophosphate compounds decompose in the time with formation of by-products of the mercaptan class to which, according to this patent, the unpleasant odour of these insecticides is due. It is also stated that the use of oxidizing agents, as made in the process of U.S. Pat. No. 2,879,284, in many cases leads to the substitution in the organophosphate compound of the sulphur atom with an oxygen atom. Therefore according to the prior art the treatment with oxidizing agents such as peroxides can jeopardize the chemical stability of the organophosphate compounds. The treatment described in U.S. Pat. No. 3,714,301 seems to be very effective for purifying the active.
In fact in the patent it is reported that the active remains substantially odourless even after a few weeks from the treatment, even after the compound is kept at 50° C.
In U.S. Pat. No. 4,851,217 an aqueous composition of organophosphates containing a non ionic surfactant, to which urea for reducing the odour of the formulation is added, is described.
However it is known that in aqueous formulations the organophosphate insecticides tend to crystallize and therefore the stability of the aqueous compositions of organophosphates is generally unsatisfactory.
In the agro field the need was felt to have available compositions under the EC form, thus essentially anhydrous comprising as active ingredients insecticidal compounds of the organophosphate class, wherein after dilution of the formulation with water at the active application dose the odour was substantially reduced or eliminated during the field application, and at the same time the chemico-physical stability and the biological activity of the formulation, as well as its handling and safety characteristics for the users were maintained.
In this way the user would safely carry out the field distribution of the diluted compositions if at the application dose the unpleasant odour of the organophosphates was substantially reduced or even eliminated.
Furthermore from the industrial point of view remarkable advantages would be obtained, as in the synthesis of the active the purification step of removing the odour from the organophosphate active would be eliminated.
It has been surprisingly and unexpectedly found by the Applicant that this technical problem is solved by adding to an EC composition containing insecticidal compounds selected from the organophosphate class, the additives as indicated hereinafter.
An object of the present invention are EC (emulsifiable concentrate) formulations comprising (% by weight):
By substantial immiscibility in water it is meant that the organic solvent is insoluble in water at room temperature (20-25° C.) at concentrations of the solvent in water higher than 3% by weight.
The compounds having insecticidal activity of the organophosphate class can be used separately or in admixture. They are characterized by the fact that they contain in the molecule the above reported group of formula (I).
The insecticides used in the formulations of the present invention are well known. See for example the book “Pesticide Manual” Ed. 2013, Index 4, page 1436, reporting the formulas of the compounds belonging to the organophosphate class and also the references to the methods for their synthesis.
Preferably the organophosphate compounds used in the EC formulation have the following formula (II):
wherein:
L1, L2, L3 and M are as defined above,
A is selected from one of the following groups:
When A is C1-C10 alkyl, the alkyl is preferably C1-C4 alkyl and in the aliphatic chain the optional heteroatom substituent is sulphur and the optional substituent group is S=0; halogen is preferably chlorine and the R3 alkyl of the ester group is C1H5.
When A is C1 alkyl the phthalimido substituent is linked to the C1 alkyl through the nitrogen atom; when the substituent is the group [1,3,4-thiadiazol-2(3H)-one-yl] one hydrogen atom of the carbon atom at position 5 of the ring is substituted with OCH3, the nitrogen atom at position 3 of the ring is linked to A=C1 alkyl; when the substituent is 3,4-dihydro-4-oxobenzo[d]-[1,2,3]-triazinyl the nitrogen atom at position 3 of the triazine is linked to A-C1 alkyl; in the case of 2,3-dihydro-2-oxo-1,3-benzoxazolyl and of 2-oxo[1,3]-oxazole[4,5-b]pyridin-3(2H)-yl the halogen atom linked to the carbon atom at position 6 is chlorine; the nitrogen atom at position 3 of 2,3-dihydro-2-oxo-1,3-benzoxazolyl is linked to A-C1 alkyl; the nitrogen atom at position 3 of 2-oxo[1,3] oxazole[4,5-b]pyridin-(2H)-yl is linked to A=C1 alkyl.
When A is a linear alkyl C1-C10 the one or more halogen atoms optional substituents of the chain end carbon atom are chlorine; when the C1-C10 chain is ethyl, on the carbon atom adjacent to the atom M in formula II preferably one hydrogen atom is substituted with chlorine and on the other carbon atom the three hydrogen atoms of the methyl group are substituted with chlorine atoms.
When A is an aromatic ring as defined above one hydrogen atom at para position of the aromatic ring is optionally substituted with one group selected from halogen, selected from bromine and chlorine; CN; NO2; SCH3; when in the aromatic ring in para position there is an halogen atom in ortho position there is a chlorine atom; when in para position there is a NO2 group, a methyl group is optionally present in meta position; when in para position there is a group SCH3, there is a methyl group in meta position; the group COOR3 is preferably in ortho position.
R3 alkyl of COOR3 is preferably C3H7, more preferably it is isopropyl.
When A is pyridinyl, the carbon atom linked to the atom M of formula II is at position 2 of the pyridinyl ring and one hydrogen atom of the carbon atoms respectively at position 3, 5 and 6 of the ring is substituted with one halogen atom, preferably chlorine.
When A has the meaning of —(C═O)CH3, M in formula II is NH.
When A is a 2-oxo-2H-chromenyl substituent, radical of coumarin, the carbon atom at position 7 of the ring is linked to M, one hydrogen atom linked to the carbon atom at position 3 is substituted with one chlorine atom and one hydrogen atom linked to the carbon atom at position 4 is substituted with methyl.
When A has the meaning of pyrimidinyl, the carbon atom linked to M is at one of the following positions of the pyrimidinyl ring: 2, 4 or 5; when there is an halogen substituent preferably is chlorine; the R3 group, when present, is preferably at position 6 and it is preferably C3H7, more preferably isopropyl; and also at position 4 a CH3 group is optionally present; when at position 6 there is a CH3 group, at position 2 a diethylamino group is optionally present; preferably one hydrogen atom linked to the carbon atom at position 2 is substituted with C4H9, preferably C4H9 is tert-butyl.
When A has the meaning of 1,2-oxazolyl, the carbon atom of the oxazole ring at position 3 is linked to M, the phenyl substituent is preferably linked to the carbon atom at position 5 of the oxazole ring.
When A is a pyrazolyl substituent, the phenyl substituent is linked to the nitrogen atom at position 1; the halogen substituent of the phenyl ring is preferably chlorine and is in para position; the carbon atom of the pyrazolyl ring at position 4 is linked to M.
When A has the meaning of 1,6-dihydro-6-oxo-pyridazinyl, the carbon atom at position 3 of the ring is linked to M; the phenyl group is linked to the nitrogen atom at position 1 of the ring.
In particular the preferred organophosphate compounds are the following: Acephate, azamethiphos, azinphos-ethyl, azinphos-methyl, cadusafos, chlorethoxyfos, chlorfenvinphos, chlormephos, chlorpyrifos, chlorpyrifos-methyl, coumaphos, cyanophos, demeton-S-methyl, diazinon, dichlofenthion, dichlorvos, dicrotophos, dimethoate, dimethylvinphos, disulfoton, ethoprophos, famphur, fenamiphos, fenitrothion, fenthion, heptenophos, isofenphos-methyl, isopropyl-O-(methoxyamino thiophosphoryl) salicylate, isoxathion, malathion, methamidophos, methidathion, mevinphos, monocrotophos, naled, omethoate, oxydemeton-methyl, parathion, parathion-methyl, phenthoate, phorate, phosalone, phosmet, phosphamidon, pirimiphos-methyl, profenofos, prothiofos, pyraclofos, pyridaphenthion, quinalphos, tebupirimfos, temephos, terbufos, thiometon, triazophos, trichlorfon, vamidothion.
The most preferred are chlorpyrifos, chlorpyrifos methyl, dimethoate, phosmet.
Preferably the amount of the organophosphate compounds in the EC formulation, expressed as percent by weight, is comprised between 20 and 25%.
The fatty acids C10-C20 saturated or unsaturated and mixtures thereof that are used in the form of their corresponding methyl and/or ethyl esters as additive A) in the formulations of the present invention, as said, derive from vegetal oils. These fatty acids methyl and/or ethyl esters are commercially known also with the trade name biodiesel. These esters are obtained by transesterification of vegetal oils with methyl or ethyl alcohol. Preferably the vegetable oils used are rape oil, soya oil, sunflower seed oil, canola, etc.
The chain of said C10-C20 vegetable acids can contain one or more unsaturations of the ethylene type, preferably in a number not higher than 3 and preferably in alternated positions along the chain. Still more preferably the unsaturations are not adjacent, i.e. there is no carbon atom bearing two double bonds.
As fatty acids derived from vegetal oils the following can be cited: lauric acid, myristic acid, palmitic acid, stearic acid, linoleic acid, linolenic acid, oleic acid.
Preferably as additive A) methyl esters of vegetable acids C10-C20 are used.
The fatty acids have preferably a C12-C18 chain length.
The ethyl and/or methyl esters of the carboxylic C10-C20 acids known with the trade name biodiesel used in the present invention are characterized by the following analytical parameters:
The additive B) is preferably in an amount, expressed as percent by weight with respect to additive A), from 5 and 40%, the amount of additive B), referred to the composition of the EC formulation (% by weight) being preferably in the range ≥0.5% and ≤8%.
The additive B) must be soluble at the above given concentrations in the solvent of the EC formulation, giving clear solutions.
Generally one part by weight of additive B) is soluble at room temperature (20-25° C.) in at least 1-5 parts of the used solvent.
The additive B) is preferably selected from the group of alkylethers of cellulose and esters of carboxyalkylcellulose.
When additive B) is an alkylether of cellulose, the alkyl of the alkylether is C1-C5; as alkylethers of cellulose, methylcellulose, ethylcellulose, propylcellulose, butylcellulose can for example be mentioned.
When additive B) is an ester of a carboxyalkylcellulose, the ester group has a C1-C4 alkyl chain and the alkyl of carboxyalkylcellulose is C1-C4.
Preferably the active is soluble in the organic solvent of the formulations of the present invention for at least 10%, more preferably for at least 20% by weight.
The active concentration in the solvent of the EC formulation in the range % by weight set forth above is such that preferably the active is dissolved in the solvent giving a clear limpid solution at room temperature.
Generally the organic solvents used in the formulations of the present invention have a volatility lower than 0.10 according to ASTM D3539 (ref.: butylacetate=1); or a volatility higher than 100 according to DIN 53170 (ref.: ethyl ether=1).
Examples of organic solvents that can be used in the EC formulations of the present invention are the following:
The surfactants are present in the formulation of the present invention in an amount comprised between 5 and 12% by weight.
The surfactants that can be used in the EC formulations of the present invention are selected from non ionic and anionic surfactants.
The non ionic surfactants are for example selected from the following: linear or branched polyethoxylated C10-C18 fatty alcohols, wherein the ethoxyl number (EO) preferably ranges from 5 to 10; polyethoxylated castor oil wherein the ethoxyl number preferably ranges from 15 to 40, more preferably 25-35; polyethoxylated distyrylphenols having an ethoxyl number preferably comprised between 12-25, more preferably 15-20; polyethoxylated tristyrylphenols having an ethoxyl number 15-40, preferably 16-25; C12-C18 mono-di and tri-esters of polyethoxylated sorbitan wherein the ethoxyl number ranges from 4 to 20, for example sorbitan monolaurate 4-20 EO, sorbitan monopalmitate 20 EO, sorbitan monostearate 4-20 EO, sorbitan trioleate 20 EO, sorbitan tristearate 20 EO, sorbitan monooleate 20 EO, commercially known as Tween 80®; C10-C16 alkyl polyglycosides (ethers of pyranosides or their oligomers), optionally polyethoxylated or polypropoxylated, generally commercially available in mixtures wherein said alkylpolyglycosides have a different ethoxyl or propoxyl number, generally comprised between 10 and 25; polyethoxylated-polypropoxylated C8-C14 aliphatic alcohols; polyaryl phenolethoxylated wherein the ethoxyl/propoxyl number is comprised between 15 and 40.
The anionic surfactants are preferably selected from the following: alkaline or alkaline-earth salts of C8-C16 alkylbenzensulphonates, for example calcium dodecyl-benzensulphonate; alkaline or earth-alkaline salts of C10-C14 alkylsulphates, preferably the corresponding calcium or sodium salts.
Preferably in the formulation of the present invention mixtures of non ionic and anionic surfactants are used.
In the mixtures of non ionic and anionic surfactants the percentage of non ionic surfactants is preferably comprised between 40 and 80%, preferably 40-70%, referred to the total percent weight of the surfactants in the EC formulation.
The EC formulations of the present invention in addition to organophosphate insecticides, optionally contain pesticides of classes different from the organophosphates. These optional pesticides are selected depending on the intended application, with the proviso that the added optional pesticides are soluble at the used concentrations in the organic solvent of the emulsifiable concentrate (EC). In this case the solvent percentage in the formulation is decreased of an amount equal to that of the optional pesticides added for maintaining 100% by weight of the composition. The amounts of the optional pesticides added are those known in the prior art.
A further object of the present invention is a process for preparing the EC formulation, comprising the following steps:
a) solubilization of the organophosphate active and of the optional pesticide in the organic solvent used for the EC preparation,
b) addition of one or more surfactants selected from non ionic and anionic surfactants or thereof mixtures,
c) addition of the additive A) and of additive B), optionally by heating at temperatures not higher than about 40° C. to obtain a limpid liquid composition.
In steps a) and c) the compounds dissolved in the solvent of the EC formulation give a solution that at room temperature is clear (limpid).
A further object of the present invention is the use of additive A) in admixture with additive B, as defined above, to reduce the odor deriving from the field distribution of the solvent formulations under the EC form, diluted with water at the application dose, and containing as active one or more insecticidal compounds of the organophosphate class.
As said, the Applicant has surprisingly and unexpectedly found that the addition of the mixture of additives A) and B) of the present invention to solvent formulations under EC form, containing as active one or more organophosphate compounds as defined above, diluted with water at the application dose, allows to substantially reduce or eliminate the odor developed during field distribution in field of these insecticides.
Furthermore the Applicant has surprisingly and unexpectedly found that the chemico-physical stability, the biological activity, the handling and safety characteristics are substantially maintained when to the EC formulations the additives of the present invention as defined above are added.
The following examples are given for illustrative and not limitative purpose of the present invention.
Characterization
Acid Value
The determination is carried out according to AOCS cd 3d-63.
Iodine Value
The determination is carried out according to Oleon OA-020.
Residual Water
The determination is carried out according to AOCS Ca 2e-84.
Density
The determination is carried out according to ISO 3675.
Odour Evaluation
A field application in an orchard has been simulated by using an atomizer. 300 ml of the formulated product have been diluted in 100 l (liters) of water. About 1500 l/ha have been used.
A group of 9 persons was trained for odour evaluation according to the following score numerical scale:
Three evaluation meeting assessments respectively at 2, 6 and 24 hours from the application in field have been overall carried out. The numerical values of the scores processed by statistical computing by using an ARM software. The statistical analysis has been based on Bartlett's test and Student-Newman-Keuls (S-N-K) multiple comparison test.
Preparation of an EC Formulation Containing Chlorpyriphos-Methyl
23 g of technical chlorpyriphos-methyl having 97% purity are mixed with 52.29 g of Solvesso® 150 ND under stirring. 6.9 g of Geronol® FF6E (mixture of calcium dodecylbenzenesulphonate and polyarylphenol ethoxylated wherein dodecylbenzene sulphonate <15% by weight and polyarylphenol ethoxylated is comprised between about 25% and about 65% by weight, the difference to 100 being solvents and 2.96 g of Geronol® FF4E (mixture of calcium dodecylbenzenesulphonate and polyarylphenol ethoxylated wherein dodecylbenzene sulphonate is comprised between 25% and about 50% and polyarylphenolethyoxylated <25%, the difference to 100 being solvents, are added. Then about 14.85 of a mixture containing, as % by weight, 77% (11.43 g) of biodiesel and 23% (3.42 g) of ethylcellulose are added under stirring by heating at 40° C.
The preparation of Example 1 was repeated but omitting the addition of the additive of the invention and adding amounts of solvent equal to those of biodiesel (11.43 g) and ethylcellulose (3.42 g) of example 1.
Evaluation of the Odour of the Formulation of Example 1 and of Example 2 Comparative
The method described in the characterization was used by employing the compositions of Example 1 and of example 2 comparative.
The results obtained (score) were the following:
The difference between the two score values was found statistically significant. This example shows that by using the formulation of Example 1 it is possible to reduce the odour of about 65% with respect to the formulation of Example 2 Comparative.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102015000014845 | May 2015 | IT | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/059798 | 5/2/2016 | WO | 00 |
