Stable herbicidal combination compositions
This is a continuation of application Ser. No. 08/439,582 filed on May 23, 1995, (abandoned) which is a continuation-in-part of application Ser. No. 08/107,410 filed on Aug. 16, 1993 (abandoned). 
    
    
     BACKGROUND OF THE INVENTION 
     In order to control a wide variety of troublesome broadleaf and grass weed species in the presence of cereal crops, especially in rice culture (upland and paddy), a combination application of one or more herbicides is generally required. The compound, 1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea is a crop-selective herbicide which is highly effective in controlling broadleaf weeds and sedges and is described in U.S. Pat. No. 5,009,699. In present day agronomic practice a number of effective grass herbicides are available which are selective in cereal crops such as dinitroaniline herbicides, thiocarbamate herbicides and chloroacetamide herbicides. However, many of these herbicides are liquids or low-melting solids and when one or more are used in combination with the above-said sulfamoyl urea to achieve broad spectrum weed control in the presence of cereal crops, the sulfamoyl urea compound may become unstable with the passage of time and lose its efficacious properties. 
     It is, therefore, an object of this invention to provide a stable combination herbicide composition for the control of noxious grass and broadleaf plant species and sedges which plague cereal crops, especially upland rice crops and paddy rice fields. 
     SUMMARY OF THE INVENTION 
     This invention relates to a stable herbicidal composition which comprises 1-{[o-cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea in combination with one or more low-melting of liquid herbicides and alkaline white carbon. Advantageously, the herbicidal combination composition of the invention may be used to provide excellent control of a broad spectrum of grass and broadleaf weeds and sedge in the presence of growing, seeded or transplanted cereal crop plants, even after prolonged storage. 
    
    
     DESCRIPTION OF THE INVENTION 
     Cereal grains such as rice, wheat, barley, oats and rye are considered to be among the most important food crops. For example, rice is the major dietary component for greater than one-third of the world&#39;s population. Grain production, to be efficient, often requires the use of two or more herbicides in a combination application to control the full spectrum of noxious plant species, for example, those which plague rice paddy fields and upland rice crops. 
     The compound 1-{[o-(cyclopropylcarbonyl)phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea, hereinafter referred to as the sulfamoyl urea compound, is a potent crop-selective herbicide which may be used in very low quantities and is especially effective for the control of sedges and broadleaf weed species in the presence of cereal crops such as barley, wheat, oats, and rye, as well as rice. This sulfamoyl urea compound is described in U.S. Pat. No. 5,009,699. Readily available, low-melting or liquid, herbicidal agents which are chiefly used for weed control in cereal crop production and are especially effective for control of annual grass weeds are: dinitroaniline herbicides such as pendimethalin, trifluralin and the like; thiocarbamate herbicides such as esprocarb, thiobencarb, molinate and the like and chloroacetamide herbicides such as butachlor, pretilachlor, metolachlor, alachlor and the like. 
     A combination of the sulfamoyl urea compound with one or more of the low-melting or liquid herbicides would offer an efficient and effective means of controlling a broad spectrum of grass and broadleaf weeds and sedges in cereal crop production. However, the sulfamoyl urea compound demonstrates unstable properties in the presence of certain low-melting or liquid herbicides and thereby loses efficacy and greatly reduces the potential control of broadleaf weeds and sedges. By low-melting herbicides, it is meant an herbicidal compound with a melting point of 60° C. or less. 
     Surprisingly, it has been found that an herbicidal combination composition comprising the sulfamoyl urea compound in combination with one or more low-melting or liquid herbicides in the presence of alkaline white carbon demonstrates excellent stability, effective broad spectrum weed control and desirable physical properties even after standing for long periods of time. Alkaline white carbon designates silicon dioxide (SiO 2 ) sorbtive carriers with a pH of about 9-12, preferably about 10-11. Among the alkaline white carbon products suitable for use in the composition of the invention are Carplex #100 or Carplex #1120 (manufactured by Shionogi Pharmaceutical Co.), Toksil AL-1 (manufactured by Tokuyama Soda Co.), Nipsil NA (manufactured by Nippon Silica Kogyo Co.) and the like, preferably Carplex #100 or Carplex #1120. 
     The Carplex white carbons comprise amorphous hydrous silicon dioxide synthesized by the wet process and are generally known as a type of precipitated silica. The Carplex white carbons are formed by agglomerate structuring from globular basic particles of about 20 to 30 mμ. Further description of the characteristics and properties of the Carplex white carbon including Carplex #100 and Carplex #1120, is available from the trade brochure entitled &#34;CARPLEX® SHIONOGI, Amorphous hydrous silicon dioxide (SiO 2 .n H 2  O)&#34; by Shionogi &amp; Co., Ltd., Japan, which is incorporated herein by reference. 
     In one embodiment of the invention, the stable herbicidal combination composition may contain about 0.05-25.0% by weight of the sulfamoyl urea compound, preferably about 0.05-5.0%, about 1-65% by weight of a low-melting or liquid herbicide and about 2-30% by weight of alkaline white carbon. 
     In actual practice, the composition of the invention may be formulated in any of the conventional dry forms such as dusts, dust concentrates, wettable powders, fine granulars, granulars, water dispersable granulars and the like utilizing agronomically acceptable adjuvants including carriers, surfactants, binders and the like. 
     Among the carriers suitable for use in these formulations are clay, talc, diatomaceous earth, bentonite, calcium carbonate, and the like. Conventional surfactants which may be used in the above formulations are non-ionic surfactants such as polyoxyethylene alkylaryl ether, polyoxyethylene styrylphenyl ether, polyoxyethylene sorbitan fatty acid ester and the like, and ionic surfactants such as alkylsulfate, alkylarylsulfonate, alkylsulfate ester, ligninsulfonate, alkylnapthalene sulfonate formalin condensate, sulfate of polyoxyethylene alkylaryl ether, alkylamine salt, dialkylsulfosuccinate, polycarbonate and the like. Binders such as carboxymethylcellulose may be used to improve the hardness of granule formulations. 
     For a more clear understanding of the invention, specific examples thereof are set forth below. These examples are merely illustrative and are not to be understood as limiting the scope and underlying principles of the invention in any way. 
     EXAMPLE 1 
     Preparation of Granular Combination Compositions With 1-{[o-(cyclopropylcarbonyl)-phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea And A Liquid Herbicide 
     The liquid herbicide used in this example is esprocarb, a thiocarbamate herbicide. 
     The title sulfamoyl urea compound is pulverized and blended with either white carbon or alkaline white carbon. This blend is then mixed with clay or talc or CaCO 3 , bentonite and surfactants. The resultant mixture is blended, kneaded with water and extruded through a 0.7-15 mm mesh screen. The resultant granules are dried, cut and sprayed with the liquid herbicide (esprocarb). 
     Using the above procedure, the following granular compositions are obtained and shown in Table I. 
     
                                           TABLE I                                 
__________________________________________________________________________
                   wt/wt %                                                
INGREDIENT         A  B  C  D  E  F                                       
__________________________________________________________________________
Sulfamoyl urea (91.9% pure)                                               
                   0.67                                                   
                      0.67                                                
                         0.67                                             
                            0.67                                          
                               0.67                                       
                                  0.67                                    
Esprocarb (94.3% pure)                                                    
                   22.94                                                  
                      22.94                                               
                         22.94                                            
                            22.94                                         
                               22.94                                      
                                  22.94                                   
White Carbon.sup.1 (ph 5.5-6.3)                                           
                   15.0                                                   
                      1.03                                                
                         1.03                                             
                            0.83                                          
                               -- --                                      
White Carbon.sup.2 (ph 7.0-8.0)                                           
                   -- 17.5                                                
                         -- -- -- --                                      
Alkaline White Carbon.sup.3 (pH 10.1-10.6)                                
                   -- -- 17.5                                             
                            17.5                                          
                               17.5                                       
                                  17.5                                    
Clay               28.93                                                  
                      18.86                                               
                         18.86                                            
                            -- -- --                                      
CaCO.sub.3         -- -- -- 20.06                                         
                               -- --                                      
Talc               -- -- -- -- 26.09                                      
                                  22.89                                   
Bentonite - Na     25.00                                                  
                      30.00                                               
                         30.00                                            
                            30.00                                         
                               30.00                                      
                                  30.00                                   
Polycarbonate.sup.4                                                       
                   3.00                                                   
                      3.00                                                
                         3.00                                             
                            3.00                                          
                               -- 3.00                                    
Dialkyl sulfosuccinate.sup.5                                              
                   3.00                                                   
                      3.00                                                
                         3.00                                             
                            3.00                                          
                               0.8                                        
                                  3.00                                    
Styrenated phenol sulfate/                                                
                   2.00                                                   
                      2.00                                                
                         2.00                                             
                            2.00                                          
                               -- --                                      
alkylbenzene sulfonate.sup.6                                              
Epoxylated soybean oil.sup.7                                              
                   -- 1.00                                                
                         1.00                                             
                            -- -- --                                      
Carboxymethylcellulose - Na.sup.8                                         
                   -- -- -- -- 2.0                                        
                                  --                                      
__________________________________________________________________________
 .sup.1 Carplex #80 (Shionogi Pharmaceutical Co.)                         
 .sup.2 Carplex #67 (shionogi Pharmaceutical Co.)                         
 .sup.3 Carplex #100 (Shionogi Pharmaceutical Co.)                        
 .sup.4 Shallol AN103P (Daiichi Kogyo Seiyaku Co., Ltd.)                  
 .sup.5 Neocol YSK (Daiichi Kogyo Seiyako Co., Ltd.)                      
 .sup.6 New Kalgen TG74 (Takemoto Oil &amp; Fat Co., Ltd.)                    
 .sup.7 New Kalgen 800 (Takemoto Oil &amp; Fat Co., Ltd.)                     
 .sup.8 Cellogen 7A (Daiichi Kogyo Seiyako Co., Ltd.)                     
 
    
     EXAMPLE 2 
     Comparative Stability Evaluation Of Compositions Containing 1-{[o-(cyclopropylcarbonyl)-phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea And A Liquid Herbicide 
     Test compositions prepared in Example 1 are placed in a screw-capped glass sample bottle and stored in a constant temperature oven set at 40° C. The samples are analyzed for active ingredient content after 0, 1, 2 and 3 month periods. Analyses are performed by reverse phase high speed liquid chromatography. 
     The percent recovery of the sulfamoyl urea compound is calculated using the equation shown below. ##EQU1## 
     The results are shown in Table II. 
     
                                           TABLE II                                
__________________________________________________________________________
Evaluation Of The Stability Of The Sulfamoyl Urea In A Combination        
Composition With A                                                        
Liquid Herbicide And Alkaline White Carbon                                
                 Storage at 40° C.                                 
                           2 month    3 month                             
Test             Initial                                                  
                      2 month                                             
                           %     3 month                                  
                                      %                                   
Sample                                                                    
    White Carbon                                                          
            pH   Quantity.sup.1                                           
                      Quantity.sup.1                                      
                           Recovery.sup.1                                 
                                 Quantity.sup.1                           
                                      Recovery.sup.1                      
__________________________________________________________________________
IA  Carplex #80                                                           
            5.5-6.3                                                       
                 0.58 0.28 48.3  0.16 32.8                                
IB  Carplex #67                                                           
            7.0-8.0                                                       
                 0.59 0.49 83.0  0.29 49.2                                
IC  Carplex #100                                                          
            10.1-10.6                                                     
                 0.53 0.55 100   0.33 62.3                                
ID  Carplex #100                                                          
            10.1-10.6                                                     
                 0.58 0.64 100   0.52 89.7                                
IE  Carplex #100                                                          
            10.1-10.6                                                     
                 0.58 0.55 94.8  0.43 74.1                                
IF  Carplex #100                                                          
            10.1-10.6                                                     
                 0.63 0.54 85.7  0.53 84.1                                
__________________________________________________________________________
 .sup.1 Sulfamoyl urea compound                                           
 
    
     EXAMPLE 3 
     Preparation of Granular Combination Compositions Containing 1-{[o-(cyclopropylcarbonyl)-phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea And A Low-melting Herbicide 
     The low-melting herbicide used in this example is pendimethalin, a dinitroaniline herbicide. 
     The sulfamoyl urea compound is mixed with a portion of the alkaline white carbon. Pendimethalin is melted using a water bath and blended with the remaining alkaline white carbon. The two mixtures are blended together and the remaining ingredients are added. The resultant mixture is blended, kneaded with water and extruded through an 0.7-15 mm mesh screen. The resultant granules are dried and cut. 
     Using the above procedure, the compositions shown on Table III are prepared. 
     
                       TABLE III                                                   
______________________________________                                    
                   % Wt/Wt                                                
INGREDIENTS          A      B                                             
______________________________________                                    
Sulfamoyl urea (91.9% pure)                                               
                     0.67   0.67                                          
Pendimethalin (91.8% pure)                                                
                     5.76   5.76                                          
Alkaline White Carbon.sup.1                                               
                     5.98   5.98                                          
(pH 10.1-10.6)                                                            
Clay                 --     41.59                                         
Talc                 41.59  --                                            
Bentonite - Na       40.0   40.0                                          
Polycarbonate type anionics.sup.2                                         
                     3.0    3.0                                           
Dialkylsulfosuccinate.sup.3                                               
                     3.0    3.0                                           
______________________________________                                    
 .sup.1 Carplex #100 (Shionogi Pharmaceutical Co.)                        
 .sup.2 Shallol AN103P (Daiichi Kogyo Seiyaku Co., Ltd.)                  
 .sup.3 Neocol YSK (Daiichi Kogyo Seiyaku Co., Ltd.)                      
 
    
     EXAMPLE 4 
     Stability Evaluation Of Compositions Containing 1-{[o-(cyclopropylcarbonyl)-phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea And A Low-Melting Herbicide 
     Test compositions prepared in Example 3 are placed in a screw-capped glass sample bottle and stored in a constant temperature oven set at 40° C. The samples are analyzed for active ingredient content after 0, 1, 2 and 3 month periods. Analyses are performed by reverse phase high speed liquid chromatography. The percent recovery of the sulfamoyl urea compound is calculated as described in Example 2. The data are shown below in Table IV. 
     
                                           TABLE IV                                
__________________________________________________________________________
Evaluation Of The Stability Of The Sulfamoyl Urea In A Combination        
Composition With A Low-                                                   
melting Herbicide And Alkaline White Carbon                               
                 Storage at 40° C.                                 
Test             Initial                                                  
                      2 month                                             
                           2 month                                        
                                  3 month                                 
                                       3 month                            
Sample                                                                    
    White Carbon                                                          
            pH   Quantity                                                 
                      Quantity                                            
                           % Recovery                                     
                                  Quantity                                
                                       % Recovery                         
__________________________________________________________________________
IIIA                                                                      
    Carplex #100                                                          
            10.1-10.6                                                     
                 0.415                                                    
                      0.435                                               
                           100    0.443                                   
                                       100                                
IIIB                                                                      
    Carplex #100                                                          
            10.1-10.6                                                     
                 0.428                                                    
                      0.422                                               
                           98.6   0.394                                   
                                       92.0                               
__________________________________________________________________________
 
    
     EXAMPLE 5 
     Stability of a Granular Combination Composition Containing 1-{[0-(cyclopropylcarbonyl)-phenyl]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea And A Low-melting Herbicide 
     The low-melting herbicide used in this example is pendimethalin, a dinitroaniline herbicide. 
     The compositions shown in Table V are prepared using the procedure set forth in Example 3. 
     The stability evaluation is conducted using the procedure outlined in Example 4, except that the test temperature is 55° C. and the sample analyses are conducted after one, two and four week periods. The data are shown below in Table V. 
     
                       TABLE V                                                     
______________________________________                                    
Evaluation of the Stability of the Sulfamoyl Urea in a                    
Combination Composition with a Low-melting Herbicide and                  
Alkaline White Carbon.                                                    
       wt/wt %                                                            
       VA    VB      VC      VD    VE    VF                               
______________________________________                                    
Composition:                                                              
Sulfamoyl                                                                 
         0.6     0.6     0.6   0.6   0.6   0.6                            
Urea                                                                      
Pendi-   5.0     5.0     5.0   5.0   5.0   5.0                            
methalin                                                                  
Carplex #80                                                               
         6.0     6.0     (--)  (--)  (--)  (--)                           
Carplex #67                                                               
         (--)    (--)    6.0   6.0   (--)  (--)                           
Carplex #100                                                              
         (--)    (--)    (--)  (--)  6.0   6.0                            
Clay     (--)    41.6    (--)  41.6  (--)  41.6                           
Talc     41.6    (--)    41.6  (--)  41.6  (--)                           
Bentonite-Na                                                              
         40.0    40.0    40.0  40.0  40.0  40.0                           
Stability:                                                                
Initial  0.517   0.553   0.534 0.534 0.497 0.500                          
55° C.,                                                            
         0.440   0.454   0.505 0.433 0.504 0.512                          
1 Week                                                                    
55° C.,                                                            
         0.358   0.352   0.469 0.337 0.472 0.472                          
2 Weeks                                                                   
55° C.,                                                            
         0.357   0.327   0.449 0.294 0.482 0.419                          
4 Weeks                                                                   
(Recovery                                                                 
         (69.1)  (61.4)  (84.1)                                           
                               (55.1)                                     
                                     (97.0)                               
                                           (83.8)                         
%)                                                                        
______________________________________                                    
 
    
     EXAMPLE 6 
     Stability of a Granular Combination Composition Containing 1-{[0-(cyclopropylcarbonyl)-phenyl]-sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea And A Liquid Herbicide 
     The liquid herbicide used in this example is molinate, a thiocarbamate herbicide. 
     The compositions shown in Table VI are prepared using the procedure set forth in Example 1. 
     The stability evaluation is conducted using the procedure outlined in Example 2, except that the test temperature is 55° C. and the sample analyses are conducted after two week and four week periods. The data are shown below in Table VI. 
     
                       TABLE VI                                                    
______________________________________                                    
Evaluation Of The Stability Of The Sulfamoyl Urea In A                    
Combination Composition With A Liquid Herbicide And                       
Alkaline White Carbon                                                     
        wt/wt %                                                           
        VIA   VIB     VIC    VID   VIE   VIF                              
______________________________________                                    
Composition:                                                              
Sulfamoyl 0.22    0.22    0.22 0.22  0.22  0.22                           
Urea.sup.1                                                                
Molinate.sup.2                                                            
          8.40    8.40    8.40 8.40  8.40  8.40                           
Carplex #80                                                               
          4.28    4.28    4.28 (--)  (--)  (--)                           
Carplex #100                                                              
          (--)    (--)    (--) 4.28  4.28  4.28                           
Clay      45.1    (--)    (--) 45.1  (--)  (--)                           
Talc      (--)    45.1    (--) (--)  45.1  (--)                           
CaCO.sub.3                                                                
          (--)    (--)    45.1 (--)  (--)  45.1                           
Bentonite-Na                                                              
          40.0    40.0    40.0 40.0  40.0  40.0                           
Neocol YSK.sup.3                                                          
          1.0     1.0     1.0  1.0   1.0   1.0                            
Shallol   1.0     1.0     1.0  1.0   1.0   1.0                            
AN103P.sup.4                                                              
Stability:                                                                
Initial   0.183   0.168   0.149                                           
                               0.129 0.122 0.138                          
55° C., 2 Weeks                                                    
          0.172   0.157   0.136                                           
                               0.121 0.111 0.126                          
55° C., 4 Weeks                                                    
          0.093   0.072   0.009                                           
                               0.115 0.092 0.073                          
(Recovery %)                                                              
          (50.8)  (42.9)  (6.0)                                           
                               (89.1)                                     
                                     (75.4)                               
                                           (52.9)                         
______________________________________                                    
 .sup.1 95.3% Pure                                                        
 .sup.2 97.6% Pure                                                        
 .sup.3 Neocol YSK (Daiichi Kogyo Seiyaku Co., Ltd.)                      
 .sup.4 Shallol AN103P (Daiichi Kogyo Seiyaku Co., Ltd.)                  
 
    
     EXAMPLE 7 
     Stability of a Granular Combination Composition Containing 1-{[0-(cyclopropylcarbonyl)-phenyl]-sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea And A Liquid Herbicide 
     The liquid herbicide used in this example is butachlor, a chloroacetamide herbicide. 
     The compositions shown in Table VII are prepared using the procedure set forth in Example 1. 
     The stability evaluation is conducted using the procedure outlined in Example 6. The data are shown below in Table VII. 
     
                       TABLE VII                                                   
______________________________________                                    
Evaluation Of The Stability Of The Sulfamoyl Urea In A                    
Combination Composition With A Liquid Herbicide And                       
Alkaline White Carbon                                                     
       wt/wt %                                                            
       VIIA  VIIB    VIIC    VIID  VIIE  VIIF                             
______________________________________                                    
Composition:                                                              
Sulfamoyl                                                                 
         0.66    0.66    0.66  0.66  0.66  0.66                           
Urea.sup.1                                                                
Butachlor.sup.2                                                           
         8.33    8.33    8.33  8.33  8.33  8.33                           
Carplex #80                                                               
         5.01    5.01    5.01  (--)  (--)  (--)                           
Carplex #100                                                              
         (--)    (--)    (--)  5.01  5.01  5.01                           
Clay     41.0    (--)    (--)  41.0  (--)  (--)                           
Talc     (--)    41.0    (--)  (--)  41.0  (--)                           
CaCO.sub.3                                                                
         (--)    (--)    41.0  (--)  (--)  41.0                           
Bentonite-Na                                                              
         40.0    40.0    40.0  40.0  40.0  40.0                           
Neocol YSK                                                                
         2.0     2.0     2.0   2.0   2.0   2.0                            
Shallol  3.0     3.0     3.0   3.0   3.0   3.0                            
AN103P                                                                    
Stability:                                                                
Initial  0.549   0.542   0.558 0.549 0.542 0.535                          
55° C.,                                                            
         0.481   0.494   0.496 0.490 0.492 0.504                          
2 Weeks                                                                   
55° C.,                                                            
         0.452   0.446   0.462 0.444 0.467 0.464                          
4 Weeks                                                                   
(Recovery                                                                 
         (37.3)  (77.6)  (82.8)                                           
                               (80.9)                                     
                                     (86.2)                               
                                           (86.7)                         
%)                                                                        
______________________________________                                    
 .sup.1 95.3% Pure                                                        
 .sup.2 &gt;90% Pure                                                         
 
    
     EXAMPLE VIII 
     Preparation Of Granular Combination Compositions With 1-{[o-(cyclopropylcarbonyl)-phenol]sulfamoyl}-3-(4,6-dimethoxy-2-pyrimidinyl)urea And A Low-Melting Solid Or A Liquid Herbicide 
     Using the procedures described in Examples I and III, the following low-melting or liquid herbicides may be used in combination with the title sulfamoyl urea to prepare a stable herbicidal composition. 
     
         ______________________________________                                    
Herbicide            mp °C.                                        
______________________________________                                    
Trifluralin          48.5°-49°                              
Thiobencarb          3.3°                                          
Pretilachlor         liquid                                               
Alachlor             39.5°-41.5°                            
Metolachlor          liquid                                               
______________________________________