Patent Publication Number: US-5290751-A

Title: Plant-protection suspensions comprising sucroglycerides

Description:
This application is related to copending applications Ser. No. 07/804,327, filed Dec. 9, 1991 and Ser. No. 07/820,416, filed Jan. 15, 1992. 
     The present invention relates to new aqueous plant-protection suspensions. Active substances such as insecticides, germicides, herbicides, fungicides, acaricides, nematicides, molluscicides, rodenticides, attractants, repellents, and combinations of these compounds, are generally insoluble in water. They can normally be used in solutions with organic solvents, wherein these solutions are emulsified in water at the time of their use. However, the use of solvents, such as xylenes or kerosine, presents obvious problems of environmental pollution. 
     Another mode of preparation of compositions of active substances consists of fluid aqueous dispersions, or &#34;flowable&#34; dispersions, which are diluted at the time of their use. These aqueous dispersions contain one or more surface-active agents. 
     Increasingly, more serious consideration is being given to the various problems of environmental pollution. Plant-protection compositions which are less and less toxic are being sought. 
     The present invention provides an alternative to environmentally harmful plant-protection suspensions through the use of a surface-active system which comprises, at least in part, non-toxic, non-irritant and biodegradable compounds. The emulsive and dispersive nature of sucroglycerides is known for preparing dispersed aqueous systems of fatty substances. Sucroglycerides are mixtures of products obtained by transesterification of natural or synthetic triglycerides with sucrose. These mixtures include monoglycerides, diglycerides, small quantities of nonesterified triglycerides, monoesters and diesters of sucrose. 
     European patent application EP-A-0,091,331, which describes a process for the preparation of flowable sucroglycerides, also discloses that sucroglycerides have surface-active properties, which may be used for the preparation of emulsions of essential oils or recombined milk. Sucroglycerides may also be combined with lecithins and flowable oils. 
     Swiss patent CH 423,442 describes a process for the preparation of emulsions of oils or solid fatty substances in water, using sucroglycerides and a lecithin as an emulsifying system. 
     The present invention uses the dispersive ability of sucroglycerides for obtaining stable suspensions of active plant-protection substances. A concentrated aqueous suspension of a solid active substance, having a melting point greater than or equal to 45° C., is produced which is substantially insoluble in water. The suspension contains the active substance, sucroglycerides, at least one compound selected from an alkoxylated triglyceride, an alkoxylated fatty acid, a sorbitan ester, and an alkoxylated sorbitan ester, and water. 
     Preferably, a wetting agent is added to these suspensions. Particularly a wetting agent is added to the more concentrated suspensions, such as suspensions containing more than 30 % by weight of active substance per volume of aqueous suspension. 
     Preferably, the invention comprises a concentrated aqueous suspension of a solid active substance, wherein the solid active substance has a melting point greater than or equal to 45° C. and is significantly insoluble in water. The concentrated aqueous suspension contains the active substance, sucroglycerides, at least one selected from an alkoxylated triglyceride, an alkoxylated fatty acid, a sorbitan ester and an alkoxylated sorbitan ester, a wetting agent selected from anionic salts of surface-active agents, alkoxylated alcohols or phenols, silicone-based surface-active agents and fluorinated surface-active agents, and water. 
     As previously indicated, sucroglycerides are obtained from the transesterification of triglycerides with sucrose. In the present text, the term &#34;sucroglycerides&#34; is used in the plural to indicate that they are not composed of only one chemical compound. The triglycerides of saturated or unsaturated aliphatic acids with at least 4 carbon atoms are preferably used. Preferably, the acids from which the triglycerides are derived have 10 to 20 carbon atoms. 
     The preparation of the sucroglycerides may be carried out using synthetic triglycerides obtained by the reaction of glycerol and fatty acids. However, it is more useful from an economic point of view to use natural triglycerides. These natural triglycerides are mixtures of triglycerides. 
     Examples of natural triglycerides are lard, tallow, groundnut oil, butter oil, cottonseed oil, linseed oil, olive oil, palm oil. grape-seed oil, fish oil, soya-bean oil, castor oil, colza oil, copra oil, and coconut oil. 
     In the present invention, the sucroglycerides used are preferably obtained from palm oil, lard, copra oil, tallow, colza oil, and castor oil. They are either in liquid form such as sucroglycerides of colza oil or castor oil, or in the form of more or less thick pastes, which are distinguishable notably by their melting point: 
     sucroglycerides of lard 47° to 50° C. 
     sucroglycerides of tallow: 50° to 55° C. 
     sucroglycerides of palm oil: 55° to 58° C. 
     sucroglycerides of copra oil: 60° to 62° C. 
     A method of preparation of sucroglycerides is described in French patent 2,463,512. 
     The aqueous suspension may also contain a phospholipid in combination with the sucroglycerides. Examples of phospholipids are crude lecithins of plant or animal origin, such as soybean lecithin or egg-yolk lecithin, as well as any lecithin fraction. 
     The aqueous suspension preferably comprises from 0.1% to 5% by weight of sucroglycerides, or optionally sucroglycerides and phospholipid, relative to the total volume of the suspension, and preferably from 0.2% to 4% by weight/volume. When a phospholipid is present with the sucroglycerides, the weight ratio of sucroglycerides/phospholipid is preferably 3:1 to 1:3. 
     The active plant-protection substance used in the present invention is substantially insoluble in water, preferably its solubility in water at 20° C. is lower than 5 g/liter. Furthermore, the active substances used must be stable with respect to water. 
     Nonrestrictive examples of active substances which can be used in the suspensions in accordance with the present invention are deltamethrin, propham, tetramethrin, furalaxyl, heptachlor, propanil, oxadiazon, triflumizole, dimethamethrin, atrazine, diuron, neburon, linuron, isoproturon, simazine, ametryne, phenmedipham, and pendimethalin. 
     The suspensions in accordance with the present invention also comprise at least one compound selected from an alkoxylated triglyceride, an alkoxylated fatty acid, a sorbitan ester and an alkoxylated sorbitan ester, and preferably comprise at least one selected from ethoxylated triglycerides, ethoxylated fatty acids, sorbitan esters and ethoxylated sorbitan esters. 
     The ethoxylated triglycerides may be ethoxylated triglycerides of plant or animal origin such as lard, tallow, groundnut oil, butter oil, cottonseed oil, linseed oil, olive oil, palm oil, grape-seed oil, fish oil, soya-bean oil, castor oil, colza oil, copra oil or coconut oil. 
     The ethoxylated fatty acids are preferably ethoxylated esters of fatty acids such as oleic acid or stearic acid. 
     The sorbitan esters are preferably cyclic sorbitol esters of from C 10  to C 20  fatty acids such as lauric acid, stearic acid or oleic acid. These sorbitan esters may also be ethoxylated. 
     The term ethoxylated triglyceride, in the present invention, applies to products obtained by ethoxylation of a triglyceride with ethylene oxide, as well as to those obtained by transesterification of a triglyceride with a polyethylene glycol. 
     Similarly, the term ethoxylated fatty acid includes products obtained by ethoxylation of a fatty acid with ethylene oxide, as well as those obtained by esterification of a polyethylene glycol with a fatty acid. 
     The alkoxylated triglycerides, alkoxylated fatty acids, sorbitan esters and/or alkoxylated sorbitan esters preferably represent from 0.1% to 3% by weight per volume of the suspension and, more preferably, from 0.2% to 2.8% by weight/volume. 
     The wetting agent is a compound as defined in the standard NF T 73-000. Examples of wetting agents are anionic salts of surface-active agents, alkoxylated alcohols or alkoxylated alkylphenols which are represented by the following formulae: 
     R 1  --SO 3  --M 
     R 2  --SO 4  --M 
     R 3  --(EO) n  --H 
     R 3  --(PO) n  --H 
     R 3  --(EO--PO) n  --H 
     R 4  --COONa 
     where: 
     R 1  represents 
     an alkylphenyl radical such as dodecylphenyl, 
     an alkyl radical such as dodecyl, 
     a 1,2-bis(octyloxycarbonyl) ethyl radical, preferably 1,2-bis (2-ethyl hexyloxycarbonyl) ethyl, 
     R 2  represents 
     an alkyl radical such as dodecyl, 
     an ethoxylated alkylphenol radical such as ethoxylated nonylphenol with 2 to 50 EO units, 
     an ethoxylated alkyl radical, 
     R 3  represents 
     an alkylaryl radical such as nonylphenyl, alkylnaphthyl, 
     an alkyl radical having from 8 to 20 carbon atoms, and preferably from 10 to 14 carbon atoms, 
     n is a number from 4 to 12, 
     R 4  represents an alkyl radical having 10 to 22 carbon atoms, 
     M represents Na, K, NH 4  or a triethanolammonium cation. 
     The wetting agent may also be a silicone-based surface-active agent such as a copolymer of (1) polydimethylsiloxane and (2) either a homopolymer of ethylene glycol or a copolymer of ethylene glycol and propylene glycol. The wetting agent may also be a fluorinated surface-active agent such as a compound containing a hydrophobic Or oleophobic perfluorocarbon linear chain and a hydrophilic region containing, for example, an acidic or neutralized sulphonic group, a carboxylic group or an ethoxylated alcohol radical. 
     The suspensions generally contain from 0.05% to 1% by weight of wetting agent relative to the total volume of the suspension, and preferably from 0.1% to 0.8% by weight/volume. 
     The aqueous suspensions generally contain from 30% to 90% by weight of active substance, relative to the total volume of the suspension and preferably from 40% to 85% by weight/volume. 
     The lower limit of this concentration range is not critical, and simply corresponds to the concentration which is normally considered to be the minimum for an economically viable storage of the suspensions. 
     In effect, the suspensions of the present invention are very stable with time and over a wide range of temperatures (for example between -10° C. and +54° C.). It is preferable from an economic point of view to store the suspensions in a concentrated form and to dilute them only at the time of use. 
     One of the advantages of the suspensions in accordance with the present invention is that the suspensions can be diluted to the concentration desired by the user, normally 0.5% to 2%, without problems of flocculation or sedimentation, to give dilute suspensions which remain stable during a period of use of about 24 hours. 
     Another advantage of these suspensions is that they possess some anti-foaming ability, derived from the sucroglycerides which they contain. 
    
    
     In the following illustrative examples of the invention, the quantities of the different constituents of the suspensions are given in grams for obtaining 1,000 cm 3  of suspension. 
     EXAMPLES 
     The procedure used was the same for the different examples. 
     First, the melted sucroglycerides were dispersed by mixing in water at 60° C., at 10% by weight/weight. This predispersion allowed the sucroglycerides to swell. 
     In the examples, the sucroglycerides were used in the form of a predispersion at 10% by weight/weight in water. 
     The ethoxylated triglyceride or ethoxylated fatty acid and the wetting agent were dissolved in water. The predispersion of the sucroglycerides, and also an anti-gelling compound when desired, was then added. 
     The active substance was then added in small fractions, while stirring, with an antifoaming agent when necessary. 
     The mixture was homogenized using a turbine, and then ground for a few minutes in a ball mill (glass beads of 1 mm in diameter) until an average particle size of 3 to 4 micrometers of active substance was obtained. Changes in the diameter of the particles were monitored using a granulometer. 
     A thickener (xanthan gum) was added when necessary and mixing was continued for about 30 minutes. 
     EXAMPLES 1 TO 4 AND COMPARATIVE TEST A 
     Preparation of aqueous suspensions of atrazine 
     Atrazine is a known herbicide, which has a melting point of 175° C. and a solubility in water at 25° C. of 0.028 g/l: ##STR1## 
     Following the procedure previously described, four aqueous suspensions of atrazine in accordance with the invention, and an aqueous suspension of atrazine not containing an ethoxylated triglyceride (comparative test A) were prepared. The respective compositions are shown in Table 1 below. 
     Table 1 also shows, for each of the suspensions: 
     the average diameter of particles of the active substance (in micrometers), 
     the value in seconds, for the measurement of the flow rate of the suspension (before addition of the thickener : xanthan gum) using a FORD Cup No. 4 (FC No. 4), 
     the abbreviation EO corresponds to the oxyethylene unit in the formula of the triglycerides or ethoxylated fatty acids. The antifoam agent used is a polydiorgano-siloxane. 
     All the suspensions in Examples 1 to 4 were stable: 
     more than 2 months at 45° C. and 
     more than 2 months in the temperature cycle: 24 hours at +45° C., 24 hours at -5° C. 
     Dilution with water produced suspensions of 0.5% to 2% of active substance, without flocculation or sedimentation, during a period of use of about 24 hours. 
     The suspension according to the comparative test was also stable to storage, but it was difficult to grind and flocculation was observed on dilution with water. 
     
                       TABLE 1                                                     
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Constituents of                                                           
              Exam-   Exam-   Exam- Exam- Test                            
the suspension                                                            
              ple 1   ple 2   ple 3 ple 4 A                               
______________________________________                                    
Atrazine      500 g   500 g   500 g 500 g 500 g                           
Sucroglycerides of                                                        
              150 g   80 g    100 g 100 g 150 g                           
castor oil,                                                               
10% in water                                                              
Ethoxylated castor oil                                                    
              5 g     4 g     5 g   5 g   0 g                             
(about 33 EO)                                                             
Ethoxylated copra oil                                                     
              0 g     0 g     0 g   5 g   0 g                             
(about 27 EO)                                                             
Sodium dodecyl-                                                           
              0 g     2 g     0 g   0.5 g 2 g                             
benzenesulphonate                                                         
Sodium lauryl sulphate                                                    
              2 g     0 g     2 g   0 g   0 g                             
Monopropylene glycol                                                      
              70 g    80 g    70 g  70 g  80 g                            
Xanthan gum, 2%                                                           
              50 g    50 g    50 g  50 g  50 g                            
in water                                                                  
Antifoam      1 g     1 g     1 g   1 g   1 g                             
Water (sufficient                                                         
              300 g   450 g   349 g 345 g 295 g                           
quantity to make up to                                                    
1,000 cm.sup.3)                                                           
Average diameter of                                                       
              3.1     3.1     2.8   3.2   --                              
particles (in                                                             
micrometers)                                                              
FC No. 4      17  s   15 s    35 s  22 s  --                              
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     EXAMPLES 5 to 8 
     Preparation of aqueous suspensions of atrazine 
     Following the procedure previously described, four aqueous suspensions of atrazine, whose respective compositions and properties are shown in Table 2 below (with the same abbreviations as in Table 1), were prepared. 
     As with the suspensions in Examples 1 to 4, all the suspensions in Examples 5 to 8 were stable: 
     more than 2 months at 45° C. and 
     more than 2 months in the temperature cycle: 24 hours at +45° C., 24 hours at -5° C. 
     By diluting with water, suspensions were produced with 0.5% to 2% of active substance, without flocculation or sedimentation, during a period of use of about 24 hours. 
     
                       TABLE 2                                                     
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Constituents of  Exam-   Exam-   Exam- Exam-                              
the suspension   ple 5   ple 6   ple 7 ple 8                              
______________________________________                                    
Atrazine         500 g   500 g   500 g 350 g                              
Sucroglycerides of tallow,                                                
                 100 g   50 g    80 g  50 g                               
10% in water                                                              
Ethoxylated castor oil                                                    
                 5 g     4 g     0 g   5 g                                
(about 33 EO)                                                             
Ethoxylated castor oil                                                    
                 0 g     0 g     8 g   0 g                                
(about 18 EO)                                                             
Ethoxylated copra oil                                                     
                 0 g     0 g     8 g   0 g                                
(about 27 EO)                                                             
Sodium dodecylbenzene-                                                    
                 0 g     2 g     2 g   0 g                                
sulphonate                                                                
Sodium lauryl sulphate                                                    
                 2 g     0 g     0 g   2 g                                
Monopropylene glycol                                                      
                 80 g    80 g    80 g  80 g                               
Xanthan gum, 2% in water                                                  
                 50 g    50 g    40 g  60 g                               
Antifoam         1 g     1 g     1 g   1 g                                
Water (sufficient quantity to                                             
                 338 g   388 g   354 g 505 g                              
make up to 1,000 cm.sup.3)                                                
Average diameter of particles                                             
                 2.8     3.1     3.4   3.2                                
(in micrometers)                                                          
FC No. 4         33 s    20 s    40 s  10 s                               
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     EXAMPLES 9 to 11 
     Preparation of aqueous suspensions of atrazine 
     Following the procedure previously described, three aqueous suspensions of atrazine, whose respective compositions and properties are shown in Table 3 below (with the same abbreviations as in Table 1), were prepared. 
     As with the suspensions in Examples 1 to 4, all the suspensions in Examples 9 to 11 were stable: 
     more than 2 months at 45° C. and 
     more than 2 months in the temperature cycle 24 hours at +45° C., 24 hours at -5° C. 
     By diluting with water, suspensions were produced with 0.5% to 2% of active substance, without flocculation or sedimentation, during a period of use of about 24 hours. 
     
                       TABLE 3                                                     
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                  Example  Example  Example                               
Constituents of the suspension                                            
                  9        10       11                                    
______________________________________                                    
Atrazine          500    g     450  g   500  g                            
Sucroglycerides of copra, 10%                                             
                  100    g     0    g   0    g                            
in water                                                                  
Sucroglycerides of butter, 10%                                            
                  0      g     100  g   0    g                            
in water                                                                  
Sucroglycerides of tallow, 10%                                            
                  0      g     0    g   250  g                            
in water                                                                  
Ethoxylated castor oil                                                    
                  5      g     5    g   5    g                            
(about 33 EO)                                                             
Sodium dodecylbenzene-                                                    
                  2      g     2    g   2    g                            
sulphonate                                                                
Monopropylene glycol                                                      
                  80     g     80   g   60   g                            
Xanthan gum, 2% in water                                                  
                  50     g     50   g   50   g                            
Antifoam          1      g     1    g   1    g                            
Water (sufficient quantity to                                             
                  338    g     380  g   208  g                            
make up to 1,000 cm.sup.3)                                                
Average diameter of particles                                             
                  3.0          3.3      3.5                               
(in micrometers)                                                          
FC No. 4          20     s     15   s   17   s                            
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     COMPARATIVE TEST B 
     Preparation of an aqueous suspension of atrazine 
     Following the procedure previously described, an aqueous suspension of atrazine, whose composition and properties are indicated below (with the same abbreviations as in Table 1), was prepared: 
     
         ______________________________________                                    
atrazine                 500    g                                         
phosphoric esters (mono- and                                              
                         20     g                                         
di-) of ethoxylated tristyryl-                                            
phenol (16 EO) neutralized with                                           
triethanolamine                                                           
ethoxylated nonylphenol (10 EO)                                           
                         5      g                                         
monopropylene glycol     80     g                                         
xanthan gum, 2% in water 50     g                                         
antifoam                 1      g                                         
water to 1,000 cm.sup.3  420    g                                         
Average diameter of particles (in                                         
                         3.6                                              
micrometers)                                                              
FC No. 4                 18     s                                         
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     As with the suspensions in Examples 1 to 4, the suspension of test B was stable: 
     more than 2 months at 45° C. and 
     more than 2 months in the temperature cycle 24 hours at +45° C., 24 hours at -5° C. 
     By diluting with water, suspensions were produced with 0.5% to 2% of active substance, without flocculation or sedimentation, during a period of use of about 24 hours. 
     It should be noted that using the compositions in accordance with the invention, containing nontoxic and biodegradable sucroglycerides, the same stability can be obtained at high concentration of active substance as with the best prior art suspensions. 
     EXAMPLES 12 to 15 
     Preparation of aqueous suspensions of diuron 
     Diuron is a known herbicide, with a melting point of 158° C. and a solubility in water at 25° C. of 0.042 g/l: ##STR2## 
     Following the procedure previously described, four suspensions of diuron, whose respective compositions are shown in Table 4 below (with the same abbreviations as in Table 1), were prepared in accordance with the invention. 
     As with the suspensions in Examples 1 to 4, all the suspensions in Examples 12 to 15 were stable: 
     more than 2 months at 45 ° C. and 
     more than 2 months in the temperature cycle 24 hours at +45° C., 24 hours at -5° C. 
     By diluting with water, suspensions were produced with 0.5% to 2% of active substance, without flocculation or sedimentation, during a period of use of about 24 hours. 
     
                                           TABLE 4                                 
__________________________________________________________________________
Constituents of the suspension                                            
                   Example 12                                             
                         Example 13                                       
                               Example 14                                 
                                     Example 15                           
__________________________________________________________________________
Diuron             600                                                    
                      g  600                                              
                            g  600                                        
                                  g  550                                  
                                        g                                 
Sucroglycerides of castor oil                                             
                   100                                                    
                      g  150                                              
                            g  150                                        
                                  g  100                                  
                                        g                                 
10% in water                                                              
Ethoxylated castor oil (about 33 EO)                                      
                   5  g  8  g  11 g  5  g                                 
Ethoxypropoxylated nonylphenol                                            
                   0  g  0  g  0  g  2  g                                 
Ethoxylated nonylphenol (about 12 EO)                                     
                   0  g  3  g  0  g  0  g                                 
Ethoxylated nonylphenol (about 8 EO)                                      
                   5  g  0  g  0  g  0  g                                 
Ethoxylated nonylphenol (about 1 EO)                                      
                   0  g  0  g  3  g  3  g                                 
Dioctyl sodium sulphosuccinate                                            
                   0  g  0  g  1  g  0  g                                 
Monopropylene glycol                                                      
                   70 g  70 g  70 g  70 g                                 
Xanthan gum, 2% in water                                                  
                   50 g  50 g  50 g  50 g                                 
Antifoam           1  g  1  g  1  g  1  g                                 
Water (sufficient quantity to                                             
                   370                                                    
                      g  318                                              
                            g  314                                        
                                  g  402                                  
                                        g                                 
make up to 1,000 cm.sup.3)                                                
Average diameter of particles                                             
                   3.8   3.7   3.5   3.3                                  
(in micrometers)                                                          
FC No. 4           35 s  30 s  28 s  27 s                                 
__________________________________________________________________________
 
    
     EXAMPLES 16 to 20 
     Preparation of aqueous suspensions of diuron 
     Following the procedure previously described, five aqueous suspensions of diuron, whose respective compositions are shown in Table 5 below (with the same abbreviations as in Table 1), were prepared in accordance with the invention. 
     As with the suspensions in Examples 1 to 4, all the suspensions in Examples 16 to 20 were stable: 
     more than 2 months at 45° C. and 
     more than 2 months in the temperature cycle 24 hours at +45° C., 24 hours at -5° C. 
     By diluting with water, suspensions were produced with 0.5% to 2% of active substance, without flocculation or sedimentation, during a period of use of about 24 hours. 
     
                       TABLE 5                                                     
______________________________________                                    
Constituents of                                                           
             Exam-   Exam-   Exam- Exam- Exam-                            
the suspension                                                            
             ple 16  ple 17  ple 18                                       
                                   ple 19                                 
                                         ple 20                           
______________________________________                                    
Diuron       600 g   580 g   640 g 640 g 640 g                            
Sucroglycerides of                                                        
             150 g   145 g   140 g 140 g 140 g                            
copra oil,                                                                
10% in water                                                              
Ethoxylated castor oil                                                    
             5 g     0 g     0 g   5 g   5 g                              
(about 33 EO)                                                             
Ethoxylated castor oil                                                    
             0 g     5 g     5 g   0 g   0 g                              
(about 18 EO)                                                             
Ethoxylated nonyl-                                                        
             5 g     3 g     4 g   5 g   3 g                              
phenol (about 10 EO)                                                      
Ethoxylated C.sub.11 fatty                                                
             0 g     0 g     0 g   0 g   5 g                              
acid (about 7 EO)                                                         
Sodium dodecyl-                                                           
             3 g     3 g     2 g   0 g   0 g                              
benzene sulphonate                                                        
Dioctyl sodium                                                            
             0 g     0 g     0 g   2 g   0 g                              
sulphosuccinate                                                           
Monopropylene glycol                                                      
             70 g    70 g    60 g  60 g  60 g                             
Xanthan gum, 2%                                                           
             50 g    50 g    40 g  40 g  40 g                             
in water                                                                  
Antifoam     1 g     1 g     1 g   1 g   1 g                              
Water (sufficient                                                         
             316 g   336 g   321 g 320 g 319 g                            
quantity to make up                                                       
to 1,000 cm.sup.3)                                                        
Average diameter of                                                       
             3.5     3.6     3.8   3.7   3.5                              
particles                                                                 
(in micrometers)                                                          
FC No. 4     30 s    35 s    40 s  40 s  38 s                             
______________________________________                                    
 
    
     EXAMPLES 21 and 22 
     Preparation of aqueous suspensions of diuron 
     Following the procedure previously described, two aqueous suspensions of diuron, whose respective compositions are shown in Table 6 below (with the same abbreviations as in Table 1), were prepared in accordance with the invention. 
     As with the suspensions in Examples 1 to 4, all the suspensions in Examples 21 to 22 were stable: 
     more than 2 months at 45° C. and 
     more than 2 months in the temperature cycle 24 hours at +45° C., 24 hours at -5° C. 
     By diluting with water, suspensions were produced with 0.5% to 2% of active substance, without flocculation or sedimentation, during a period of use of about 24 hours. 
     
                       TABLE 6                                                     
______________________________________                                    
Constituents of the suspension                                            
                     Example 21                                           
                               Example 22                                 
______________________________________                                    
Diuron               430    g      450  g                                 
Sucroglycerides of copra oil,                                             
                     120    g      0    g                                 
10% in water                                                              
Sucroglycerides of butter oil,                                            
                     0      g      100  g                                 
10% in water                                                              
Ethoxylated castor oil (about 33 EO)                                      
                     5      g      10   g                                 
Ethoxylated castor oil (about 18 EO)                                      
                     5      g      0    g                                 
Sodium dodecylbenzenesulphonate                                           
                     5      g      5    g                                 
Monopropylene glycol 70     g      70   g                                 
Xanthan gum, 2% in water                                                  
                     60     g      60   g                                 
Antifoam             1      g      1    g                                 
Water (sufficient quantity to make up                                     
                     447    g      455  g                                 
to 1,000 cm.sup.3)                                                        
Average diameter of particles                                             
                     3.2           3.5                                    
(in micrometers)                                                          
FC No. 4             10     s      12   s                                 
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     EXAMPLES 23and 24 
     Preparation of aqueous suspensions of triflumizole 
     Triflumizole is a known fungicide, with a melting point of 63° C. and a solubility in water at 25° C. of 0.012 g/l: ##STR3## 
     Following the procedure previously described, two aqueous suspensions of triflumizole, whose respective compositions are shown in Table 7 below (with the same abbreviations as for Table 1) were prepared in accordance with the invention. 
     As with the suspensions in Example 1 to 4, all the suspensions in Examples 23 and 24 were stable: 
     more than 2 months at a temperature lower than 35° C. (maximum temperature for the stability of the active substance). 
     By diluting with water, suspensions were produced with 0.5% to 2% of active substance, without flocculation or sedimentation, during a period of use of about 24 hours. 
     
                       TABLE 7                                                     
______________________________________                                    
Constituents of the suspension                                            
                     Example 23                                           
                               Example 24                                 
______________________________________                                    
Triflumizole         430    g      500  g                                 
Sucroglycerides of tallow,                                                
                     130    g      0    g                                 
10% in water                                                              
Sucroglycerides of castor oil, 10%                                        
                     0      g      200  g                                 
in water                                                                  
Ethoxylated castor oil (about 33 EO)                                      
                     8      g      20   g                                 
Sodium dodecylbenzenesulphonate                                           
                     3      g      0    g                                 
Sodium lauryl sulphate                                                    
                     0      g      3    g                                 
Monopropylene glycol 60     g      70   g                                 
Xanthan gum, 2% in water                                                  
                     50     g      50   g                                 
Antifoam             1      g      1                                      
Water (sufficient quantity to make up                                     
                     374    g      220  g                                 
to 1,000 cm.sup.3)                                                        
Average diameter of particles                                             
                     4.2           4.5                                    
(in micrometers)                                                          
FC No. 4             39     s      46   s                                 
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