FR2740004A1 - Granules for spreading active material on soil for plant health - Google Patents

Abstract

Granules for spreading on soil comprises: (a) at least one copolymer of maleic anhydride and di-isobutylene as the salt; (b) at least one alkoxylated mono-, di- or tri-(styryl)phenol. The weight ratio of components (a) : (b) is 40:60-99:1.

Description

PELLETING GRANULES
The subject of the present invention is spreading granules comprising, in addition to the phytosanitary active ingredient, a particular dispersing agent.

 Unlike all types of existing phytosanitary formulations, such as emulsions, aqueous solutions, wettable powders in particular, spreading granules have the advantage of being able to be applied as such, safely for the user, and with a great ease of use.

 Moreover, the granules must be formulated in such a way as to have a good resistance to attrition as well as a good aptitude not to break during storage.

 In addition, these granules must disintegrate easily in contact with the ground or rice fields, and allow a maximum dispersion of the phytosanitary active ingredient on the surface to be treated.

 Granules of this type are known, based on a phytosanitary active ingredient, and on a mineral additive. Such granules, however, are not satisfactory in that they do not have good properties for any kind and amount of mineral additive. In addition, the spreading surface is not very good.

 It is possible to optimize the spreading surface of the active material by adding to the aforementioned formulation an amphiphilic polymer with dispersing properties and a surfactant chosen from ethoxylated alkylphenols. However, if the spreading surface is increased, there still remain difficulties related to the compatibility between the load and the surfactant and the adaptation between the active ingredient and the dispersant. These difficulties mean that when the content of active ingredient is as high as 30%, the active ingredient contained in these resulting granules is difficult to disperse.

 The present invention solves the problems described previously.

Thus, the particular dispersing agent used in the composition of the granules according to the invention makes it possible to have high levels of active material without there being problems of compatibility. Therefore, under unfavorable conditions for dispersion, that is to say of high content of active material, spreading surfaces reached are important.

 Furthermore, the present invention makes it possible to use the mineral additive in a wide range of concentrations, while resulting in a granule having good disintegration and spreading properties.

 The present invention likewise relates to spreading granules whose properties are conserved for a broad spectrum of mineral additive compositions and especially for low levels of this additive.

 The present invention also has the advantage of offering granular phytosanitary formulations that do not depend on the hardness of the water.

 Finally, the dispersing agent gives the spreading granules according to the invention better resistance to attrition, while retaining a good ability to disintegrate when applied to the soil to be treated.

 These and other objects are achieved by the present invention which therefore relates to spreading granules comprising, as dispersing agent, [a] at least one maleic anhydride / di-isobutylene copolymer in salt form, [b] at least one alkoxylated mono-, di-, or tri- (styryl) phenol; the compounds [a] and [b] being present in a weight ratio [a] / [b] of between 60/40 and 99/1.

 The dispersing agent used in the composition of the spreading granules according to the present invention comprises at least one diisobutylene maleic anhydride copolymer in the form of a salt (compound [a]).

 More particularly, the copolymer is in the form of a salt soluble in water.

 Thus, alkali metal salts such as sodium, potassium, alkaline earth metal salts such as calcium, or ammonium salts of formula NR 4 +, with R, are suitable for carrying out the invention. , identical or different, representing a hydrogen atom or a C 1 -C 4 alkyl radical, optionally substituted with an oxygen atom;

 The copolymer [a] can be obtained by any means known to those skilled in the art.

Thus, in general, copolymerization of maleic anhydride with diisobutylene is carried out in the presence of a suitable solvent and then the resulting copolymer is hydrolyzed with a base.

 The molar proportion between maleic anhydride and di-isobutylene is generally between 1/4 and 4/1. More particularly, the copolymerization is carried out in the presence of an equimolar mixture of the two monomers.

 By way of example of copolymer [a], mention may be made of GEROPON T136 marketed by Rhône-Poulenc Geronazzo.

 The second compound falling within the definition of the dispersing agent according to the invention consists of at least one alkoxylated mono-, di- or tri- (styryl) phenol (compound [b]).

 According to a particular embodiment, alkoxylated (styryl) phenols comprising 2 to 40 oxyalkylenated units are used. By oxyalkylenated units or by (styryl) phenols alkoxylated means oxyethylenated units, oxypropylene or mixtures thereof, or alcohols comprising such units. More particularly, the number of oxyalkylenated units is between 2 and 40, and preferably between 6 and 20.

 By way of example of such compounds, mention may be made, without intending to be limited to ethoxylated di (styryl) phenol, containing 5 oxyethylenated units, ethoxylated di (styryl) phenol, containing 7 oxyethylenated units, tri (styryl) ethoxylated phenol containing 8 oxyethylenated units, ethoxylated tri (styryl) phenol containing 16 oxyethylenated units.

 According to a particular variant, at least partially sulphated alkoxylated (styryl) phenols are used. Preferably, the alkoxylated (styryl) phenols in the composition of the dispersing agent are completely sulfated. Such products are conventionally obtained by reacting the alcohol with a sufficient quantity of an acid comprising at least one amine function and at least one SO 3 H function, such as sulphamic acid.

 By way of example of such compounds, mention may be made, without intending to be limited to sulfated ethoxylated di (styryl) phenol containing 5 oxyethylenated units, sulphated ethoxylated di- (styryl) phenol, containing 7 oxyethylenated units, Sulfated ethoxylated phenol (styryl) phenol containing 10 oxyethylenated units, sulfated ethoxylated di- (styryl) phenol containing 15 oxyethylene units, sulfated ethoxylated tri- (styryl) phenol containing 16 oxyethylenated units.

 Another variant of the present invention consists in using a compound [b] in at least partially neutralized form, or more particularly completely neutralized form. This type of product can in particular be obtained by reacting the sulphated product with a sufficient amount of a base, such as the alkali metal hydroxides, or with an amine or an alkanolamine, such as ethanolamine, for example.

 In the case where the compounds [a] are used in neutralized form, partially or totally, the counterion is an alkali metal, such as sodium or potassium, or an ammonium ion of formula NR 4 + in which R, identical or different, represent a hydrogen atom or a C 1 -C 4 alkyl radical optionally substituted by an oxygen atom.

 The weight ratio between the compound [a] and the compound [b] is between 60/40 and 99/1.

 According to a particular variant, the weight ratio [a] / [b] is between 50/50 and 90/10.

 It has been found, in a totally surprising manner, that the combination of the above-mentioned compounds [a] and [b] made it possible to overcome the difficulties created by variable water hardness and to maintain good performance with the phytosanitary formulations incorporating them. .

 The spreading granules according to the present invention comprise at least one solid phytosanitary active substance.

Suitable solid phytosanitary materials include, for example, Carbaryl, Bendiocarb, Benfuracarb, Carbofuran, Carbosulfan,
Chlorpropham, Furathiocarb, Isoprocarb, Propham, Aclonifen, Oxyfluorfen, MCPA
Thioethyl, 2,4-D, MCPB. These can be used alone or mixed.

 The granules further comprise at least one mineral additive.

 Any conventional additive for this type of application can be used.

 Thus, calcium carbonate, kaolin, talc, silica, clay, bentonite are suitable mineral additives.

 The spreading granules according to the invention also comprise the usual additives of the phytosanitary formulations. Thus, they generally contain at least one binding agent such as starch, gelatin, polyvinyl alcohol, carboxymethylcellulose, microcrystalline cellulose, in particular.

 The spreading granules may further comprise at least one anti-caking agent such as sodium carbonate or bicarbonate, calcium chloride, molecular sieves, silica, for example.

The granules according to the invention may furthermore comprise disintegrating agents such as, for example, ammonium or sodium phosphates,
Sodium acetate, magnesium, zinc or calcium sulphates.

 It may be further advantageous to include chemical stabilizing agents such as in particular sodium hexametaphosphate, alkali or alkaline earth metal citrates, dipropylene glycol.

 The amount of compound [a] used in the formulation of the granules according to the invention varies between 0.1 and 20% by weight relative to the same reference as above. Preferably, the content of compound [a] varies between 5 and 10% by weight.

 The content of compound [b] is more particularly between 0.1 and 10% by weight relative to the same reference. Preferably, the content of compound [b] is between 0.5 and 5% by weight. According to a particularly advantageous variant, the content of compound [b] is between 0.5 and 2% by weight.

 Of course, the phytosanitary formulation according to the invention verifies the weight ratio [a] / [b] previously indicated, ie 40/60 to 99/1, and preferably 50/50 to 90/10.

 The phytosanitary active substance content is between 5 and 50% by weight relative to the total weight of the formulation. More particularly, it varies between 5 and 30% by weight.

 The spreading granules according to the present invention additionally have an amount of mineral additive of from 20 to 90% by weight. Preferably, this is between 30 and 90% by weight.

 The amount of conventional additives generally represents between 0 and 20% by weight.

 The processes for preparing the dispersing agent and the spreading granules according to the invention will now be described.

 The dispersing agent can be prepared by simple mixing during the preparation of the phytosanitary formulation itself.

 However, according to a particularly advantageous embodiment, said dispersing agent is prepared extemporaneously.

 According to a first variant of the preparation of said agent, a solution, preferably aqueous, of the compounds [a] and [b] is prepared in the required proportions.

 The drying can take place in any way known to those skilled in the art.

 However, it is preferred to use a co-atomization drying which makes it possible to directly obtain a powder comprising in a homogeneous manner the two compounds.

 Conventional co-atomization techniques are suitable, such as the use of BUCHI-type apparatus or such as that described in US patents (LEA FLASH).

 According to a second embodiment of extemporaneous preparation of the dispersing agent, an impregnation of a mineral support with the compounds [a] and [b] is carried out in the required proportions.

 According to an entirely advantageous variant of this embodiment, a compound which corresponds to the definition given previously of the mineral additives used in the composition of the granules according to the invention is used as mineral carrier.

 This impregnation can take place by having previously heated said compounds to liquefy them and then spray them on the mineral support.

 It is also possible to prepare one or two aqueous solutions of compounds [a] and [b] which will be sprayed subsequently on the inorganic support. A drying step will then be desirable.

 Of course, it is not beyond the scope of the present invention by combining these two modes of impregnation of the inorganic support.

 The spreading granules according to the invention are prepared by mixing the aforementioned various constituents in the required proportions, using conventional methods.

 Thus, the various constituent elements of the formulation are brought into contact, in an indifferent order, simultaneously or successively, in a powder mixer, of the LÖDIGE type, for example.

 Then 2 to 15% by weight of water relative to the weight of the constitutive elements of the phytosanitary formulation, more particularly 3 to 7%, are added in order to granulate the mixture.

 Such an operation is conventionally carried out in a bezel, a turbosphere for example.

 It is also possible to extrude the humidified mixture through a die or a grid.

 It should be noted that the dispersing agent consisting of compounds [a] and [b] can be incorporated with the solids in solid form, or incorporated with the granulation water in the form of a suspension or an aqueous solution. .

 Once the mixture is shaped, drying is carried out under fluidized air.

 The duration of the operation is such that it makes it possible to obtain a mixture comprising a residual water content of less than 2% by weight.

 As an indication, the duration of the drying varies between 20 and 90 minutes and more precisely between 20 and 40 minutes.

 The drying temperature is usually between 40 and 100 ° C and preferably between 50 and 70 ° C.

 The concrete but non-limiting examples of the present invention will now be presented.

EXAMPLES
EXAMPLE 1
The examples illustrate the preparation of the spreading granules.

The following compositions are prepared:

<tb> Composition <SEP> (% <SEP> weight / weight) <SEP> 1 <SEP> 2 <SEP> comparative
<tb> CARBARYL <SEP> (insecticide) <SEP> 10 <SEP> 10
<tb> Agent <SEP> dispersing
<tb><SEP> -GEROPONT / 36 <SEP> 2 <SEP> 2
<tb><SEP> - <SEP> SOPROPHOR <SEP> 4D <SEP> 384 <SEP> 1
<tb><SEP> - <SEP> Laurylsulfate <SEP> from <SEP> Na <SEP> 1
<tb> Additive <SEP> mineral
<tb><SEP> - <SEP> silica
<tb><SEP> - <SEP> carbonate <SEP> of <SEP> Ca <SEP> 87 <SEP> 87
<Tb>
The mixture is dry milled in an air jet mill; particle size of the order of 10 to 20 μm is obtained.

 The particles are then agglomerated with 18 parts of water per 100 parts of particles, in a LODIGEX apparatus (marketed by LODIGE).

 The agglomerate is then extruded through a die 0.8 mm in diameter.

 The granules are then dried in a fluid bed AEROMATICB (marketed by NIRO) until a residual moisture of 2% of said granules.

EXAMPLE 2
This example is intended to illustrate the properties of comparative compositions 1 and 2.

 The application performance of this type of spreading granule is expressed as a spreading area after disintegration on the surface of the moist soil.

 The conditions of this application test are as follows: the test is carried out in a crystallizer 15 cm in diameter, filled with water to a depth of 1 cm; 1 gram of granules is gently poured into the center of the crystallizer on the surface of the water and the area covered by the dispersion obtained from the disintegrating granules is measured as a function of time. The diameter of the spreading spot covered by the dispersion of the disintegrated granules is noted and the resulting area calculated.

The results for composition 1 are summarized below:

<tb> hardness <SEP> of <SEP> Surface <SEP> of spread <SEP> in <SEP> disintegration <SEP> (cm2) <SEP>
<tb><SEP> the water <SEP> 10 <SEP> mns <SEP> I <SEP> 30 <SEP> mns <SEP> 60 <SEP> mns
<tb><SEP> 20 <SEP> ppm <SEP> 44 <SEP> 52 <SEP> 60
<tb><SEP> 60 <SEP> ppm <SEP> 44 <SEP> 64 <SEP> 64
<tb><SEP> 342 <SEP> ppm <SEP> 54 <SEP> 64 <SEP> 64
<Tb>
The results for comparative composition 2 are summarized below ::

<tb> hardness <SEP> of <SEP> Surface <SEP> of spread <SEP> in <SEP> disintegration <SEP> (cm2) <SEP>
<tb><SEP> water <SEP> 10 <SEP> mns <SEP> 30 <SEP> mns <SEP> 60 <SEP> mns
<tb><SEP> 20 <SEP> ppm <SEP> 24 <SEP> 28 <SEP> 28
<tb><SEP> 60 <SEP> ppm <SEP> 24 <SEP> 30 <SEP> 39
<tb> 342 <SEP> ppm <SEP> 50 <SEP> 64 <SEP> 64
<Tb>
These results show that in the presence of a water of low hardness, commonly encountered for paddy field protection applications, the composition 1 is much more efficient than the comparative composition 2. Indeed, the spreading surface as a function of time is higher in the case of the composition according to the invention.

 Moreover, it is found that the surfaces reached with the granules according to the invention are important irrespective of the hardness of the water. Thus the granules comprising the dispersing agent according to the invention are effective for all conditions of the application soils.

Claims (14)

1. Spreading granule, characterized in that it comprises as dispersing agent:  [a] at least one maleic anhydride / di-isobutylene copolymer in salt form,  [b] at least one alkoxylated mono-, di-, or tri- (styryl) phenol, and has a weight ratio [a] / [b] of between 40/60 and 99/1. 2. Granule according to the preceding claim characterized in that the weight ratio  [a] / [b] is between 50/50 and 90/10. Granule according to any one of the preceding claims, characterized in that  that the compound [a] is in the form of an alkali metal salt, metal  alkaline earth metal, or an ammonium of the formula NR4 +, in which R, which are identical or  different, represent a hydrogen atom or a C1-C4 alkyl radical  optionally substituted with an oxygen atom. 4. Granulate according to any one of the preceding claims, characterized in that  that the compound [b] is in at least partially sulphated form,  preferably, totally sulfated. 5. Granule according to any one of the preceding claims, characterized in that  that the compound [b] is in at least partially neutralized form,  more particularly completely neutralized. 6. Granule according to the preceding claim, characterized in that the compound [b] is  found in the form of an alkali metal salt or an ammonium of formula NR4 +,  in which R, which are identical or different, represent a hydrogen atom or a  C1-C4 alkyl radical optionally substituted with an oxygen atom. Granule according to any one of the preceding claims, characterized in that  it comprises at least one phytosanitary solid active ingredient. Granule according to any one of the preceding claims, characterized in that  that it comprises at least one solid active ingredient chosen from Carbaryl,  Bendiocarb, Benfuracarb, Carbofuran, Carbosulfan, Chlorpropham, Furathiocarb,  Isoprocarb, Propham, Aclonifen, Oxyfluorfen, MCPA-Thioethyl, 2,4-D, MCPB. Granule according to one of the preceding claims, characterized in that  it comprises at least one mineral additive. Granule according to one of the preceding claims, characterized in that  that the mineral additive is selected from calcium carbonate, silica, clay,  bentonite, talc, kaolin. Granule according to one of the preceding claims, characterized in that  that the content of compound [a] is between 0.1 and 20% by weight, relative to  total weight of the formulation, preferably between 5 and 10%. Granule according to one of the preceding claims, characterized in that  that the content of compound [b] is between 0.1 and 10%, relative to the weight  total of the formulation, more particularly between 0.5 and 5%, preferably between 0.5 and 2%.  relative to the total weight of the formulation, preferably between 5 and 30%.  that the phytosanitary active substance content varies between 5 and 50% by weight, Granule according to one of the preceding claims, characterized in that Granule according to one of the preceding claims, characterized in that  that the mineral additive content is between 20 and 90% by weight relative to  to the total weight of the formulation, preferably between 30 and 90%.