WO2017129496A1

WO2017129496A1 - Granular compositions having insecticidal activity

Info

Publication number: WO2017129496A1
Application number: PCT/EP2017/051254
Authority: WO
Inventors: Gianluca Valieri; Marco Bernardini; Francesca Borgo; Edoardo Russo
Original assignee: S.I.P.C.A.M.Societa' Italiana Prodotti Chimici E Per L'agricoltura Milano S.P.A.; Nippon Soda Co., Ltd.
Priority date: 2016-01-29
Filing date: 2017-01-20
Publication date: 2017-08-03
Also published as: ITUB20160231A1

Abstract

Granule compositions containing as actives lambda cyhalothrin and acetamiprid, comprising (% by weight on dry basis) : lambda cyhalothrin 0.2 - 2.0 acetamiprid 0.2 - 2.0 C₉-C₂₀ alkylbenzenes wherein the alkyl is linear or when possible branched, or mixtures thereof 2.0 - 16.0 aliphatic alkyl esters C₃-C₅ of C₃-C₅ aliphatic hydroxyacids or mixtures thereof, 0.8 - 2.0 inert support in the form of porous granules, to 100 wherein the composition is stable at storage for at least two years and the release of the two actives in the soil is controlled in time.

Description

GRANULAR COMPOSITIONS HAVING INSECTICIDAL ACTIVITY

* * * * *

The present invention relates to insecticidal granule compositions containing lambda cyhalothrin and acetamiprid as actives, for directly application on the field.

More specifically, the present invention relates to granule compositions that maintain a high stability of the actives in time and allow a gradual release of the actives after field application.

In particular the compositions of the invention are prepared by means of a process as described later on. Insecticidal compositions in the form of granules are known in the prior art. See for example patent application FR 2,979,187 relating to granule compositions containing pyrethrum and at least another insecticidal active selected from various classes, among which neonicotinoids . By the term pyrethrum in the French patent application it is meant both pyrethrum, pyrethrins and pyrethroids. No mention is made in this patent application to a granule composition containing the combination of the two actives lamba cyahalothrin and acetamiprid.

In the document it is reported that the granules can be prepared according to the process described in patent application WO 2010/007,240. This process comprises the following steps:

1 Preparation of a premix of actives with an absorptive filler, for example silica, bentonite, kaolin;

2a preparation of a mixture comprising the pre-mix of step 1 and the other ingredients of the final composition;

2b addition of water to the mixture;

2c mixing and formation of an extrudable paste;

3 extrusion to obtain granules; 4 drying of the granules obtained in step 3.

The drawback of the granules obtained with this prior art process is that the actives in these compositions are easily washed away once the granules are distributed on the field. Therefore soil persistence of the active is reduced and biological activity is not prolonged in time as requested, and in any case it is insufficient for obtaining an effective field treatment.

It is in fact known that the efficacy of insecticidal granule formulations depends on their property of disintegrating and/or of releasing the actives in the soil to maintain an effective insecticidal activity for the time requested.

This property depends also on environmental factors such as for example the water content of soil and the washing away action of rain. Therefore the release of the active from the granules to the soil can result unsatisfactory for achieving a prolonged insecticidal activity as requested in the application.

Furthermore the Applicant has also found that the composition of the granules can directly affect the stability in time of the active (s) in the formulation.

The need was felt to have available granule compositions containing lambda cyhalothrin and acetamiprid having the following combination of properties:

- prolonged stability of the two actives in the granules, and

- gradual release, prolonged in time, of the two actives so to obtain in field application a prolonged insecticidal activity in the soil.

An object of the present invention are porous granule compositions containing as actives lamba cyhalothrin and acetamiprid, comprising (% by weight dry basis) : lambda cyhalothrin 0.2 - 2.0 acetamiprid 0.2 - 2.0

C9-C20 alkylbenzenes wherein the alkyl

is linear or when possible branched,

or mixtures thereof 2.0 - 16.0 aliphatic alkyl esters C3-C5

of C3-C5 aliphatic hydroxyacids

or mixtures thereof, 0.8 - 2.0 inert support in the form of

porous granules, complement to 100

wherein the porous granules have size in the range

0.1-1.5 mm.

Preferably the porous granule sizes are comprised between 0. and 1.0 mm.

Generally the alkylbenzenes have a boiling point in the range from 165°C to 310°C, preferably from 220°C to 290°C. The alkylbenzenes used in the formulations of the present invention are preferably Cio-Cie alkylbenzenes. The alkylbenzenes are solvents commercially available. The following trade names of alkylbenzenes can for example be mentioned: Solvesso® 150, Solvesso® 200, Solvesso® 150 ND, Solvesso® 200 ND, preferably without naphthalene residues such as Solvesso® 150 ND, Solvesso® 200 ND.

The aliphatic hydroxyacids C3-C5 from which the corresponding alkyl C3-C5 esters used in the formulations of the present invention are obtained, have one carboxylic group and one hydroxylic group. The esters used in the compositions of the inventions are liquid compounds miscible with water.

Alkyl esters of aliphatic hydroxyacid acids C3-C5 wherein the alkyl of the ester group is C₃, are preferred.

Among the aliphatic hydroxyacids, lactic acid is preferred . The preferred aliphatic ester is the propyl ester of the lactic acid .

he ratio by weight (C9-C20 alkylbenzenes + aliphatic C3-C5 alkyl esters of aliphatic C3-C5 hydroxyacids ) / (mixture of actives : lambda cyhalothrin and acetamipriid) generally ranges from 15:1 to 1:1, preferably 11:1 to 2.5:1.

The ratio by weight ( (C₉-C₂o alk Ibenzene) / (aliphatic C3-C5 alkyl esters of aliphatic C3-C5 hydroxyacids ) generally ranges from 0.5:1 to 13:1, preferably 1.1:1 to 8:1.

The inert support in the form of porous granules used in the compositions of the present invention must satisfy the adsorption test described for the mixture of solvents used in the formulations as in the examples. In practice the mixture of the two organic solvents to be used to solubilize the two actives is added to the granules and the amount of the adsorbed solvent mixture is de ermined .

Generally the amount of the solvent mixture adsorbed by the granules is comprised between 22% to 5% referred to the weight of the dry granule.

It has been found by the Applicant that it is not advantageous to use amounts of solvent mixtures higher than the above limit in the preparation of the granule compositions of the present invention. Therefore if the amount of the solvent mixture results higher than the % limit above reported, it is preferred to reduce it within the above reported % values by treating the formulation in a suitable drying unit located downhill the granule preparation equipment .

The inert support in the form of porous granules is not dispersible in water and has a solubility in water lower than 0.5% by weight (at 20°C) .

In the compositions of the present invention the lowest limit as % by weight of the dry inert support in the form of granules is 78%, generally 80% or higher, preferably 85%, still more preferably 90% by weight on the total of the formulation. The moisture content of the granules is lower than 2%, preferably 1.5%, determined by the method reported in the examples .

The highest limit as % by weight of the inert support in the form of granules is 95% by weight.

The pores of the granules have a diameter ranging from 0.05-0.1 μιη up to 50 μπι, depending on the granule sizes, preferably from 0.1 pm up to 20 μιη. A method for determining the diameter of the pores is described in the examples .

The porous granules used for the inert support of the present invention are made of compounds available on the market .

According to a first embodiment of the present invention the granules are formed of inorganic salts optionally comprising crystallization water molecules .

In the inorganic salts the cations are preferably selected from those of alkaline metals, preferably selected from sodium or potassium, or of alkaline-earth metals, preferably selected from magnesium or calcium.

The cations of magnesium and calcium are preferred.

The anions are preferably selected from carbonates, sulphates and silicates.

The preferred anions are selected from sulphates and silicates .

The preferred salts are selected from bihydrate calcium sulphate and magnesium silicate.

The porous granules formed of inorganic salts are prepared by known methods .

For example according to a prior art process to obtain the porous granules, in a first step the material forming the granules is milled. Then, in the order, a dry heating step, a rehydration step and a granulation step by agglomeration follow.

According to another embodimen of the invention the inert support in the form of granules com ises fertilizers .

The fertilizers are preferably a mixture of milled grounded corncob, monoammonic phosphate and leonardite in the following amounts as % by weight on the dry) :

grounded corncob 5 - 25 monoammonic phosphate 50 - 70 leonardite 20 - 30 the sum of the fertilizer components being 100%,

the monoammonic phosphate : leonardite ratio being preferably comprised between 1.5 : 1 and 3.0 : 1.

According to another embodiment of the invention the inert support in the form of granules of the formulations of the present invention is made of fertilizers only.

The milled grounded corncob and the leonardite are products commercially available,

Leonardite is a natural material obtained by oxidation of lignite . Leonardite is found associated to 1 ignite deposits next the surface of the ground. Leonardite is a material rich in humic acid and is used to improve the physical properties of the ground, in particular enriching it with nut ients for plants .

The porous granules formed of fertilizers can be prepared by granulating the mixture of the components by agglomeration, followed by a final drying step until the residual moisture content of the granules is within the above indicated limits.

he agglomeration step requires a few minutes , generally from 2 to 6 minutes.

The temperature in the final drying step is generally comprised between 100°C and 140°C.

The preferred compositions according to the present invention comprise (% by weight on the dry) :

lamba cyhalothrin 0.2-0.4 acetamiprid 0.6-1.0

C9-C20 alkyklbenzenes wherein the alkyl

is linear or when possible branched,

or mixtures thereof 2.0-8,5

C3-C5 aliphatic alkyl esters of

C3-C5 aliphatic hydroxyacids or

mixtures thereof, 0.9-1.8 inert porous support in granules to 100

To the formulation as optional additives other compounds can be added. In this case in the formulation the percentage of the C9-C20 alkylbenzenes and/or of the inert inorganic support is decreased of an amount equal to that of the added optional additives.

Overall amount of the optional additives is generally not higher than 5% by weight on the total composition.

Examples of these additives are non ionic and anionic surfactants and mixtures thereof, dispersing agents, activity modifiers, biostimulants , vegetal oils, etc.

Non ionic surfactants are for example selected from alkylarylphenols, preferably ethoxylated such as for example ethoxylated tristyrylphenols wherein the number of ethoxylation ranges from 15 to 40, preferably from 16 to 25; ethoxylated distyrylphenols wherein the ethoxyl number ranges from 12 to 25, preferably from 15 to 20; ethoxylated fatty alcohols having Cio^_C₁₈ aliphatic chain wherein preferably the number of ethoxylation ranges from 3 to 10, ethoxylated castor oil with ethoxylation number ranging from 15 to 40, preferably 25-35; ethoxylated sorbitan oleate wherein the ethoxylation number ranges from 1 to 60, preferably from 5 to 40.

Anionic surfactants are selected from salts of aromatic sulphonic acids wherein the aromatic ring is substituted with one or more C₃-Ci4 aliphatic chains. Preferably the aromatic ring is substituted with a Cs-Ci^ aliphatic chain. Examples of surfactants belonging to this class are alkaline metal and alkaline-earth metal salts of dodecylbenzensulphonic acids . These salts are known for example under the trademark Rodacal® 60 BE, the titre of the saline compound being 60% by weight. Other anionic surfactants that can be used as additives are for instance the sulphosuccinic acid salts wherein the sulphonic group is salified with alkaline or alkaline-earth metal cations and the two carboxylic groups are esterified with aliphatic Cg-Cio alcohols, such as for example sodium dioctyl- sulphosuccinate; alkylsulphate C1₀-C1 salts wherein the cation is selected from the cations of alkaline or alkaline-earth metals, preferably calcium, sodium, or ammonium, the latter being mono- bi- or tri-alkyl substituted; C₁0-C14 alkylsulphate salts wherein the cation is preferably selected between calcium or sodium.

Among the dispersing agents the following can for example be mentioned: ligninsulphonates, for example the corresponding sodium salts, available on the market for example with the following commercial names: Reax® 100M, Reax© 88 B Kraftsperse® 25 and Ultrazine® NA; calcium salts of lignin sulphonates, for example Borrement® CA; block polymers containing ethylenoxide and/or propylenoxide blocks, for example Pluronic® PE 6400, Pluronic® 10400; polycarboxylate salts, for example the corresponding sodium salts, such as for example Geropon® TA 72. The activity modifiers are compounds able to modify the activity of the insecticides of the formulations of the present invention. The following can for example be mentioned :

- synergic agents of the active ingredients, such as for example PBO (piperonylbutoxide) and Verbutin (4-[l-(2- butin-l-yloxy) ethyl] -1 , 2-dimethoxy benzene)

pherormones (sexual pherormones ) , cairohormones, etc. The biostimulants are selected from extracts of seaweeds having a content of organic material comprised between 45 and 55%, the complement to 100% being formed of inorganic compounds, and from mixtures of aminoacids deriving from hydrolytic processes of proteins of vegetal origin. As an example of seaweed extracts the alga E extracts, in particular that from the species Ascophyllum nodosum, can for example be mentioned.

It has been surprisingly and unexpectedly found by the Applicant that the compositions of the invention have a prolonged stability in time (shelf life) .

Tests carried out by the Applicant have shown that the stability in time both of lambda cyhalothrin and acetamiprid in the porous granule compositions not dispersible in water according to the present invention depends on the solvents used for preparing the mixture used to solubilize the two actives according to the preparation process described further on.

The Applicant has in fact found that by using in the preparation of the formulation of the present invention solvents different from those indicated above, such as for example dimethylsulphoxide, formulations that do not show the desired shelf-life are obtained.

According to the Applicant this fact is unexpected, as it is well known in the art to use dimethylsulphoxide as a solvent in agro formulations. For instance it is used to solubilizc neonicotinoids , see for example WO 2010/145,994.

Furthermore it has been found by the Applicant that if in a granule composition containing lambda cyhalothrin and acetamiprid it is found that one or both actives are not stable, the addition of compounds known in the prior art as stabilizing additives of these actives does not improve the shelf-life of the formulation. For example the addition to a formulation of the two actives wherein lambda cyhalothrin has been found not stable of an additive stabilizing lambda cyhalothrin, such as for example epoxidated linseed oil (Lankroflex® L) does not improve the stability of lambda cyhalothrin in the formulation.

It has been also found that in the formulations of the present invention the two actives show a remarkable resistance to the washing away action of rain so that after the agro application the granule formulation displays an effective insecticidal activity for a long period of time in the soil . See the examples . The Applicant has surprisingly and unexpectedly found that the resistance of the actives to the washing away action of rai can be further improved by adding in the formulations of the present invention can be further increased by adding a compound called hereinafter antiwashing agent, selected f om oils of vegetal origin such as rape oil, soya oil , sunflower seed oil , canola, etc . Preferably rape oil is used . The amount of the oil of vegetal origin is no more than 3% and preferably comprised between 0.5% and 2% with respect to the composition weight .

The vegetal oil is preferably added together with a second additive selected from the class of anionic surfactants , the latter in amounts not higher than 0.5% by weight on the total composition, preferably comprised between 0.05% and 0.5%. Preferably the anionic surfactant is sodium dodecylbenzensulphonate .

As said, the overall amount of the additives of the formulation of the present invention is not higher than 5% by weight.

Further compounds that can be used as antiwashing agents are ethoxylated fatty alcohols having a Cio-Cie aliphatic chain, the ethoxylation number ranging from 3 to 10.

Preferred compositions of the invention are the following (% by weight) :

Composition 1)

lamba cyhalothrin 0.29 acetamiprid 0.80 C9-C20 alkylbenzenes 7.80 propyl ester of lactic acid 1.00 inert support in the form of porous granules

having size in the range 0.1-1.5 mm to 100%

Composition 2)

lamba cyhalothrin 0.30 acetamiprid 0.80 C9-C20 alkylbenzenes 6.60 propyl ester of lactic acid 1.00 rape oil 1.00 sodium dodecylbenzensulphonate 0.18 inert support in the form of porous granules

having size in the range 0.1-1.5 mm to 100%

A further object of the present invention is a process for preparing the compositions of the invention, comprising the following steps:

a) preparation of a liquid mixture of organic solvents formed of C₉-C₂o alkylbenzenes and C3-C5 alkyl esters of C3-C5 aliphatic hydroxyacids, optionally an oil of vegetal origin as an additive;

b) heating of the liquid mixture at a temperature comprised between 40°C and 60 °C;

c) addition to the liquid mixture of the two actives lambda cyhalothrin and acetamiprid and formation of a soluti on;

d) addition to the solution of the optional additives;

e) adsorption of the obtained solution onto the porous granules of the inert support .

In the process of the present invention oil of vegetal origin can be alternatively added in step d) , together with the other optional coformulants .

Preferably the antiwashing agents (rape oil and/or ethoxylated fatty acids CiQ-Cig with ethyoxyl number from 3 to 10) are added in step a) .

In step c) a limpid organic solution of the two actives is obtained .

In step e) the amount of the solution used for the adsorption of the actives onto the granules is preferably not higher than 10% by weight, calculated on the total of the composition (adsorbed solution as prepared in steps a) to d) + inert support) .

In practice the amount of solution to be adsorbed onto the inert support (granules) is such as to allow the complete adsorption of the solution onto the granules . After step e) the granules maintain their initial aspect, i.e. before carrying out the adsorption step e) , Their surface appears dry that is not wetted by the mixture of organic solvents. At the same time in this step (step e) } the amount used of each of the two solvents i the mixture must be enough to solubilize the two actives in the amounts required for preparing the formulation.

Step e) can be carried out by any method known in the art. For example it can be carried out by spraying while keeping the granules under stirring for obtaining an homogeneous application. It has been found by the Applicant that the solutions prepared in steps a) -c) or a)-d) when the optional additives are present, applied by spraying, do not show inconveniences due for example to clogging of the nozzles owing to the active crystallization.

A further object of the present invention is the use of the granule composition according to the present invention for a field insecticidal treatment by distribution at a dosage comprised between 5 and 25 kg/ha, preferably between 10 and 20 kg/ha.

Preferably the distribution in the field is carried out in the seeding.

The following examples are given for illustrative and not limitative purposes of the present invention.

EXAMPLES

CHARACTERIZATION

Determination of the granulometry

Granulometry is determined by the CIPAC MT 58 method. Sieves having a diameter of 200 mm and a nominal aperture mesh sizes as indicated in Table I are used.

Table I

Nominal mesh aperture sizes of the sieves Standard ISO

565 (BS410:1986)

*8.00 425 *1.40 75

6.70 *355 1.18 *63

*5.60 300 *1.00 53

4.75 *250 *45

.00 2123 38

3.35 *180 32

The indicated sizes with asterisk * are those commonly used .

Determination of the moisture content of the granules

The moisture is determined by drying an amount (wo) of granules not lower than 5 grams in a stove at 40°C for 12 hours, Wf being the final weight. The moisture content is given by [ (wo-Wf) x 100] /wo.

Determination of lambda cyhalothrin in the granule

The active is determined according to the method CIPAC

463//TC/M/-, resumed hereinafter.

The method is based on the extraction of a sample of granules with dichloromethane using as internal standard hexacosane and subsequent gaschromatographic analysis.

The solutions of the samples to be analyzed and of the standard solution are prepared in duplicate.

The solution of the internal standard is prepared by dissolving in a 500 ml volumetric flask 2 g of hexacosane in dichloromethane and then bringing to volume.

The solution of lambda-cyhalothrin standard is prepared by weighing about 0.1 g of lambda cyhalothrin in each of two 150 ml volumetric flasks. To each of the two solutions 20 ml of the internal standard solution and then 30 ml of dichloromethane are added by a pipette. The liquid phase in the volumetric flasks is stirred until dissolution of the lambda cyhalothrin. 5 ml of each of the two solutions are diluted in a 25 ml volumetric flask with dichloromethane. The solution of the sample is prepared by weighing in two 150 ml volumetric flasks, an amount of the sample containing about 0.1 g of lambda cyhalothrin. In each of the two flasks 20.0 ml of hexacosane solution, 30 ml of dichloromethane are added. The mixture is stirred for dissolving the lambda cyhalothrin. Preferably in this step an ultrasound bath is used to make the solubilization of the active more rapid. 5 ml of each solution are filtered and the filter is washed until bringing to volume with dichloromethane in a 25 ml volumetric flask.

It is used a capillary gaschromatographic column 25 m x0.25 mm (i.d.) or 50 m x 0.32 mm (i.d.), wherein the inner wall is covered with a 0.12 μπι thick coating of dimethylsiloxane .

An automatic sampler is used. The volume injected is 1.0 μΐ . The oven temperature is 210°C_/ that of the injector 300°C and of the detector 300°C.

Sample injection, as said, is automatically carried out. The gas chromatograph detector is a flame ionization detector .

The oven temperature is controlled so to have a retention time of the lambda cyhalothrin comprised between 10.7 and 11.4 min and of hexacosane between 12.2-13.0 min. The oven temperature should however not exceed 240 °C.

Flow-rate of the carrier gas (helium or hydrogen) is of 1 ml/min.

The results are expressed as % by weight on a dry basis.

Determination of acetamiprid

The CIPAC 469/TC/{M)/ test is used, summarized hereinafter. The determination is carried out by extracting the granules with acetonitrile/water 1/1 (v/v) , determining then the active amount in the granules on an HPLC reverse phase column (Ci_B) .

As internal standard a solution of coumarin is used, prepared by weighing in 500 ml volumetric flask 15 g of the compound, adding about 400 ml of acetonitrile, under stirring until dissolving the coumarin and then bringing to volume .

100 mg of acetamiprid standard are weighed in a 100 ml volumetric flask and 20 ml of an internal standard solution are added by a pipette and the mixture is diluted to volume with acetonitri le/water 1/1 (v/v) . In a 10 ml volumetric flask 400 μΐ of this solution are added and diluted to volume with the acetonitrile/water 1/1 mixture .

In a 100 ml volumetric flask an amount of granules equal to 100 mg of acetamiprid, are transferred . 20 ml of the internal standard solution are added and the volume is brought to about 40 ml . The mixture is filtered in a second 100 ml flask and the first flask and the filter are washed in sequence with two parts of about 30 ml of the acetonitrile/water 1/1 (v/v) mixture . The solution is brought to the volume of 100 ml in the second volumetric flask . In a 10 ml volumetric flask 400 μΐ of this solution are transferred and then diluted to volume with an acetonitrile/water 1/1 (v/v) mixture .

A high pressure liquid chromatograph is used . The liquid chromatograph is equipped with a loop automatic injector (5μ1) and a UV detector at 246 nm .

The stainless steel column has 150x4.6 mm ( i . d . ) sizes and is packed with Symmetry C18 (5pm) packing materials .

The flow rate is 1.0 ml/mi n and the column temperature is 40°C.

The mobile phase is formed of a mixture acetonitrile/- water/phosphoric acid 10% in water in the ratios by weight 250/750/1 (v/v/v) .

The retention time of acetamiprid is about 5 minutes and of coumarin of about 8 minutes .

The results are expressed as % by weight on a dry basis. Adsorption test on the porous granules of the inert support In a flask a known amount of porous granules, generally comprised between 10 and 30 grams, is weighed.

Under stirring, by a burette, a mixture of solvents corresponding to the premix of step a) of the process of the present invention formed by C9-C20 alkylbenzenes and C3- C5 alkyl esters of C3-C5 aliphatic hydroxyacids is added. The addition of the solvent mixture or solvent premix is carried out dropwise and is continued until the granules maintain their initial aspect, that is their external surface maintains dry. In the presence of a solvent mixture excess it is noted that the granule surface changes aspect and it is wetted by the solvent. In the presence of a solvent mixture excess the organic mixture can be also outside the granules.

In this way it is determined if the porous granules can adsorb the amounts of the mixture of the two solvents reguested for preparing the formulation according to the present invention at the desired concentrations of the two actives .

Accelerated stability test of the granules

The test allows to forecast the stability of the granules at room temperature for a period of time over one year, generally up to two years.

The sample is conditioned for 14 days at 54°C {CIPAC MT 46.3) . At the beginning and at the end of the test the titre of the two actives is determined.

The criterium to establish that the formulation has met the test i the following . The f rmulation is considered stable if at the end of the test the titre of each of the two actives is decreased of no more than 5% with respect to the titre at the start of the test .

Determination of the diameter of the pores

The determination is carried out by means of the well known technique of mercury intrusion porosimetry . The principle of the method is the following: by using an external pressure mercury is forced into the pores of the porous material. The pore distribution is determined by the volume of mercury that is being intruded into the material at each increase of pressure .

The diameter of the pores is determined by applying the Washburn formula {E.W. Washburn, in Proceeding of the National Academy of Sciences, PNASA, Vol. 7, 1921, page 115) .

-4ycos9 d

wherein :

P is the pressure applied

Y is the mercury surface tension

Θ is the contact angle between the mercury and the sample

(>90°C) .

EXAMPLE 1

Step a) Preparation of the premix to be adsorbed on the inert inorganic support

To 79.0 g of Solvesso® 200, 10 g of Purasolv® NPL (n-propyl lactate) v/ere added, under stirring at room temperature . An homogeneous mixture was obtained .

Step b)

The mixture was brought to the temperature of 40°C.

Step c} 8.1 g of acetamiprid having 99% purity and 3.1 g of lamba- cyhalothrin having 96% purity were then added to the premix, by stirring until complete dissolution of the active so to obtain a limpid solution. In the preparation of the formulation of example 1 no additive is used. Thus step d) was not carried out.

Step e) Adsorption on the inert porous support

In a 250 ml flask 90 g of calcium sulphate bihydrate in granules having a granulometric distribution comprised between 0.3 and 0.9 mm and diameter of the pores within the limits {0.01-50 μι ) were loaded. By maintaining the granules in the flask under constant stirring an amount of 10 g of the premix prepared in step a) was sprayed on the granules .

This amount has been determined by carrying out the adsorption test described above. Stirring was continued until complete adsorption of the premix onto the porous granules. Under these conditions the mass of the granules at the end of step e) had an homogeneous aspect, that is no presence of solvent was noted either on the external surface of the granules or outside the granules. Therefore the granules maintained their initial aspect as the granule surface appeared dry, that is not wetted by the premix. The mass was discharged and the content of the two actives determined .

The analysis of the actives in the granules gave the following results: lambda-cyhalothrin 0.31%, acetamiprid 0.82% .

The accelerated stability test at 54°C for two weeks was carried out on the formulation. The results are reported in Table 2.

EXAMPLE 2 COMPARATIVE

Example 1 was repeated but substituting in step a) n-propyl lactate with an equal amount (10 g) of dimethyl sulphoxide . The analysis of the actives in the granules gave the following results: lambda-cyhalothrin 0.29, acetamiprid 0.81%.

EXAMPLE 3 COMPARATIVE

Example 2 comparative was repeated but in step a) increasing the amount of dimethylsulphoxide from 10 to 40 g and decreasing that of Solvesso® 200 from 79.0 to 49.0 g. The analysis of the actives in the granules gave the following results: lambda-cyhalothrin 0.30, acetamiprid 0.80%.

EXAMPLE 4 COMPARATIVE

The preparation of Example 2 comparative was repeated but in step a) together with 10 g of dimethylsulphoxide 54.0 g of Solvesso® 200 were added. The preparation process comprised also Step d) and was carried out by adding as additive 25 g of epoxydated linseed oil (Lankroflex® L) . The latter compound is known in the art as stabilizing agent of lambda cyhalothrin in agro compositions.

The analysis of the actives in the granules gave the following results: lambda-cyhalothrin 0.30, acetamiprid 0.79%.

EXAMPLE 5 COMPARATIVE

Example 4 comparative was repeated but omitting the addition of DMSO in step a) and of acetamiprid in step c) . In the composition the percentage of the inert support (granules) used in e) was increased of an amount corresponding to that of DMSO +acetamiprid .

In this example process steps a) -d) were carried out by mixing 0.37 g of lambda cyhalothrin with 6.58 g of Solvesso© 200 and 3.05 of Lankroflex® L) .

8.2 g of this solution were sprayed on 91.8 g of granules. The analysis of the active in the granules has shown that the content of acetamiprid was 0.31%.

TABLE 1

Composition (% by weight dry basis) of the formulations of examples 1 and 2-5 comparative on the basis of the components added in the preparation

* Titre 99%

** Titre 96% Comments to the stability tests of Table 2

The data of the accelerated stability test reported in the Table show that by substituting the premix of solvents according to the present invention with the mixture Solvesso®200 + DMSO (Ex. 2 comp . ) the titre of lambda cyhalothrin remarkably decreases (-17%) with respect to the starting t₀ titre . Furthermore also the titre of acetamiprid results lower than that at to, although still comprised in the acceptability limits (± 5% of the titre determined at to)■

The Table shows also that by increasing in the granules the DMSO amount and decreasing the amount of Solvesso®200 {Ex. 3 comp . ) the titre of lambda cyhalothrin found at the end of the stability test is further decreased (-20%) with respect to example 2 comparative. It is to be noted that the acetamiprid titre in the granule is decreased more than 6%, therefore outside the acceptability limit.

The Applicant has found that by adding to the formulation of example 2 comparative a stabilizer of lambda-cyhalothrin (Ex.4 comp.) but omitting Purasolv® NPL, the titre of both actives in the granules resulted even more lower .

Example 5 comparative shows that the composition obtained in Example 4 comparative, containing lambda cyhalothrin, Solvesso®200 and Lankroflex®, without acetamiprid and DMSO ( solvent of acetamiprid) resulted stable in the accelerated stability test. TABLE 2: for the lambda cyhalothrin active

TABLE 2: for the acetamiprid active

APPLICATION EXAMPLES

Preparation of the formulations

The formulations were prepared by following the procedure and using the same compounds as described in example 1 but, with the exception of formulation Sip 50884 that was identical to example 1, with the modifications indicated herein belo . Sip 50896

In step a) of preparation of the formulation 66 g of

Solvesso®200 together with 10 g of rape oil as antiwashing agent and 3 g of Rhodacal®60 BE {surfactant titre 60% by weight) were added.

Step c) was as in example 1.

Sip 50897

In step a) the premix was prepared by mixing 9,8 g of Purasolv®NPL, 76.7 g of Solvesso@200. 5 ,3 g of oleyl alcohol ethoxylated (4 EO) as antiwashing agent were then added .

In step c) 6.06 g of acetamiprid and 2.35 g of lambda cyhalothrin were added to the liquid mixture .

In step e) an amount of granules equal to 86.7 g was sprayed with 13.3 g of the solution prepared in steps a) -c) .

Sip 50898

In step a) 36 g of Purasolv®NPL were mixed with 42 g of Solvesso®200 to form the premix .

In step c) 16.17 g o acetamiprid and 6.25 g of lambda cyhalothrin were added to the premix.

In step e ) 95 g of granules were sprayed with 5 g of the solution prepared in steps a) -c) .

For the application examples rectangular trays having about 50 cm x 40 cm sizes were used. Each tray was filled with a soil, formed (% b weight) of 80% peat {Klasmann N-P-K: 14- 10-18) and 20% sand, pH 6.8.

The compositions used have been the following (% b weight dry basis) based on the components added in the preparation: TABLE 3

60% by weight sodium dodecylbenzensulphonate

ethylhexanol

In a tray covered with a soil having the above described composition the seeds were distributed in 2 furrows at a distance of about 10 cm one seed from the other, for a total of 8 plants. The furrows had a depth of about 2 cm and were spaced apart of about 30 cm the one from the other. For each application example three replications were carried out.

The granules of the invention were uniformly distributed in the two furrows of each tray. The amount to be distributed in each tray was the same calculated for the corresponding dose per hectar.

APPLICATION EXAMPLE 1A

In this example plant seeding was carried out at the same time of the granule embedding insecticidal treatment in the soil. The infestation, infestation insect species: aphids, was carried out 10 days after seeding. In Figure 1 the data obtained by treating with each of the 4 compositions of Table 3 at the doses of 5, 10 and 15 kg/h, are reported as % mortality of the insects evaluated after 24 hours from the infestation.

After plant seeding step the following irrigations with water were carried out:

Initial irrigation (to) until percolation of water4 through the soil bed

Daily irrigation with 50 ml/furrow

Irrigation after 7 days with 100 ml/furrow.

The control was not treated.

A statistical evaluation of the results reported in Figure 1 shows that there is no significant difference between the insecticidal efficacy of the commercial product Sonido®, consisting of pre-treated maize seeds, and the products of the invention applied at the dose of 10-15 kg/ha.

It is to be noted that the latter is the dose range employed for field application. It is to be noted also that the compositions of the invention have the advantage to have a greater persistence in the soil of the actives near the plant seeds. This is because of the slow release of the actives from the granule. Also at the doses of 5 kg/ha the persistence of the actives in the soil of the compositions of the invention is comparable (See Sip 50884) or higher (ref. Sip 50896, Sip 50897, Sip 50898) with respect to the above commercial product. Therefore the results obtained with the formulations of the invention are considered more than acceptable from the point of view of the effectiveness of the treatment .

The % mortality achieved by the composition SIP 50898 shows that it is possible to maintain or even increase the efficacy of the application with respect to SIP 50884 composition, the active concentrations being the same, also at the doses of 5 kg/ha and 10 kg/ha, by reducing the overall amount of solvent premix used in adsorption step e) of the process of the present invention.

APPLICATION EXAMPLE 2A

The same procedure of the application example la was repeated but with the following modifications.

At zero time (to) the granules were embedded.

Plant seeding was carried out after 10 days from granule embedding and infestation after 10 days from plant seeding. In Fig. 2 the % mortality of the insects at 24 h obtained with the compositions of Table 3, was reported.

The % mortality data obtained show that the compositions of the present invention applied to the soil according to the procedure described in this example allow to maintain in time a very high insecticidal activity, in particular at the doses used for field application (10-15 kg/ha) . It is noted that the composition {SIP 50896) containing rape oil shows a very high insecticidal activity, in particular at the dose of 15 kg/ha.

APPLICATION EXAMPLE 3A

The same procedure of the application example 1A was followed but with the following modifications.

At zero time (to) the granules were embedded.

Plant seeding was carried out after 20 days from granule embedding and infestation from 10 days from seeding.

In Fig. 3 the % mortality of the insects at 24 h after the infestation obtained with the treatments with the formulations of Table 3 is reported.

Fig. 3 shows that also by carrying out plant seeding after 20 days from granule embedding, the mortality is still very high. This shows that the insecticidal activity of the granule formulation is effective for a long period of time in the soil. It is observed in particular that formulation SIP 50896, containing rape oil, has shown the highest activity (mortality > 90%) at the dose of 15 kg/ha.

The results reported in the Figure show that in the insecticidal t eatment according to this example the compositions containing the antiwashing additives as defi ed above show an improved insecticidal activity with respect to those not containing these additives .

ACCELERATED STABILITY TEST (14 days at 54 °C) of the granule compositions Sip 50896, Sip 50897 and Sip 50898

An accelerated stability test described in the part "characterization" was carried out on the compositions used i the application examples .

The results {% by weight) of the active dosing obtained in the stability tests are reported in the following Table . The data show that the formulation of the invent ion satisfy the accelerated stability test, as the content of the actives found at the end of the test is within the limits (±5%) of the value .

TABLE 4

Claims

Granule compositions containing as actives lambda cyhalothrin and acetamiprid, comprising {% by weight on the dry basis) :

lambda cyhalothrin 0.2 - 2.0 acetamiprid 0.2 - 2.0

C9-C20 alkylbenzenes wherein the alkyl

is linear or when possible branched,

or mixtures thereof 2.0- 16.0 aliphatic alkyl esters C3-C5

of C3-C5 aliphatic hydroxyacids

or mixtures thereof, 0.8 - 2.0 inert support in the form of

porous granules, to 100 wherein the porous granules have

size in the range 0.1-1.5 mm.

Compositions according to claim 1 wherein the alkylbenzenes have a boiling point in the range from 165°C to 310°C.

Compositions according to claims 1-2 wherein the alkyl of the C3-C5 aliphatic hydroxyacids esters is C3 alkyl.

Compositions according to claim 3 wherein the aliphatic hydroxyacid is lactic acid.

Compositions according to claims 1-4 wherein the ratio by weight ( C9-C20 alkylbenzenes+C3-C5 aliphatic alkyl esters of C3-C5 aliphatic hydroxyacids) / (actives) ranges from 15:1 to 1:1.

Compositions according to claims 1-5 wherein the ratio by weight ( C9-C20 alkylbenzenes) / (C3-C5 aliphatic alkyl esters of C3-C5 aliphatic hydroxyacids) is comprised between 0.5:1 and 13:1.

Compositions according to claims 1-6 wherein the inert support in the form of porous granules is not dispersible in water and has a water solubility lowe than 0.5% by weight at 20 °C.

8. Compositions according to claim 7 wherein the ine t support in the form of porous granules is comprised between 80% and 95% by weight on the total formulation,

9. Compositions according to claims 1-8 wherein the pores of the granules have a diameter ranging from 0.05-0.1 pm up to 50 ]i .

10. Compositions according to claims 1-9 wherein the granules are formed of inorganic salts which optionally comprise crystallization water molecules,

11. Compositions according to claim 10 wherein the cations of the inorganic salts are selected from alkaline or earth- alkaline metals and the anions are selected from carbonates, sulphates and silicates.

12. Compositions according to claims 1-11 wherein the inert support in the form of granules comprises fertilizers.

13. Compositions according to claims 1-9 wherein the inert support in the form of granules contains a fertilizer consis ing of a mixture of the following components : grounded corncob, monoammonic phosphate and leonardite in the following amounts as % by weight on the dry :

grounded corncob 5 - 25 monoammonic phosphate 50 - 70 leonardite 20 - 30 the sum of the fertilizer components being 100%, the monoammonic phosphate : leonardite ratio being comprised between 1,5 : 1 and 3.0 : 1.

1 . Compositions according to claims 1-13 comprising

(% by weight on the dry part)

lambda cyhalothrin 0.2-0.4

ace amiprid 0.6-1.0

C9-C₂₀ alkykibenzenes wherein the alkyl

is linear or when possible branched, or mixtures thereof 2.0-8.5

C3-C10 aliphatic alkyl esters of

C3-C5 aliphatic hydroxyacids or

mixtures thereof, 0.9-1.8

inert porous support in granules to 100

Compositions according to claims 1-14 further comprising additives selected from non ionic and anionic surfactants and mixtures thereof, dispersing agents, activity modifiers biostimulants and vegetal oils, said additives being in an amount ≤5% by weight, the percentage of C9-C20 alkylbenzenes and/or of the inert inorganic support being decreased of an amount equal to that of the added additives .

Compositions according to claims 1-15, comprising (% by weight on the dry basis) :

Composition 1)

lambda cyhalothrin 0.29 acetamiprid 0.80

C9-C20 alkylbenzenes 7.80 propyl ester of lactic acid 1.00 inert inorganic support in the form of to 100 granules having size in the range 0.1-1.5 mm

17. Compositions according to claims 1-15, comprising (% by weight on the dry basis) :

Composition 2)

lambda cyhalothrin 0.30 acetamiprid 0.80

C9-C20 alkylbenzenes 6.60 propyl ester of lactic acid 1.00 rape oil 1.00 sodium dodecylbenzensulphonate 0.18 inert organic support in the form of to 100% granules having size in the range 0.1-1.5 mm

18. A process for preparing the compositions of claims 1-17 comprising the following steps:

a) preparation of a mixture of organic solvents formed of C9-C20 alkylbenzenes and C3-C5 alkyl esters of C3-C5 aliphatic hydroxyacids;

b) heating of the mixture at a temperature comprised between 40°C and 60 °C;

c} addition to the mixture of the actives and formation of a solution;

d) addition to the solution of the optional additives; c) adsorption of the solution on the porous granules of the inert porous support.

Use of the compositions according to claims 1-17 for a field insecticidal treatment at a dose comprised between 5 and 25 Kg/ha.