Herbicidal composition

Abstract

Provided is a herbicidal composition comprising a herbicidally active compound selected from a difluoromethanesulfonylanilide compound represented by the general formula (I): wherein R 1 represents a hydrogen atom, an alkyl group or an alkoxyalkyl group; or a salt thereof encapsulated in a microcapsule, or a herbicidal composition comprising the herbicidally active compound encapsulated in a microcapsule and a benzoic acid compound represented by the general formula (II): wherein R 2 represents a hydrogen atom, an alkyl group having 1 to 15 carbon atoms, a hydroxyl group, a nitro group, or an amino group; and R 3 represents a hydrogen atom, an alkali metal atom or an alkyl group. The herbicidal composition exert a pharmacological effect for a prolonged period of time, can alleviate or prevent any harmful effect and can reduce the environmental load.

1 - 9 . (canceled) 
     
     
         10 . A method for the preparation of a microcapsule for a herbicide composition comprising:
 mixing together a first reactant solution comprising (i) a herbicidal compound selected from the group consisting of difluoromethanesulfonylanilide compounds represented by the formula   
       
         
           
           
               
               
           
         
       
       wherein R 1  is a hydrogen atom, an alkyl group or an alkoxyalkyl group, and salts thereof, (ii) a hydrophobic polyisocyanate, and (iii) a hydrophobic solvent, and
 a second reactant solution which is an aqueous solution comprising (i) water, (ii) a water-soluble polymer, and optionally (iii) a hydroxyl compound, to form a mixture, and 
 heating the mixture at 60 to 90° C. under high-speed agitation at a velocity of 1,000 to 10,000 rpm, to form the microcapsule having a coating of a polyurethane or a polyurea and the herbicidal compound sealed therein. 
 
     
     
         11 . The method according to  claim 10 , wherein the hydroxyl compound is glycol or glycerol. 
     
     
         12 . The method according to  claim 10 , wherein the microcapsule has an average particle diameter of 0.1-50 μm. 
     
     
         13 . The method according to  claim 10 , wherein R 1  is a methoxymethyl group.