Stable solid herbicide delivery systems

Abstract

Herbicide delivery systems comprising a potassium salt of a herbicidal carboxylic acid coated onto a solid carrier.

1 . A herbicide delivery system comprising a solid carrier and a potassium salt of a herbicidal carboxylic acid coated onto the surface of the solid carrier, wherein the potassium salt of the herbicidal carboxylic acid is from about 0.1 gram acid equivalent per kilogram (g ae/kg) to about 100 g ae/kg of the total herbicide delivery system and the coated solid carrier is free flowing and does not cake during storage. 
     
     
         2 . The herbicide delivery system of  claim 1 , wherein the herbicidal carboxylic acid is picloram. 
     
     
         3 . The herbicide delivery system of  claim 1 , further comprising a second herbicidal carboxylic acid. 
     
     
         4 . The herbicide delivery system of  claim 3 , wherein the second herbicidal carboxylic acid is aminopyralid. 
     
     
         5 . The herbicide delivery system of  claim 1 , wherein the herbicide delivery system is a granule or a pellet. 
     
     
         6 . The herbicide delivery system of  claim 1 , further comprising one or more inert ingredients. 
     
     
         7 . The herbicide delivery system of  claim 1 , further comprising a surfactant. 
     
     
         8 . The herbicide delivery system of  claim 1 , wherein the solid carrier is limestone chips. 
     
     
         9 . The herbicide delivery system of  claim 1 , wherein the herbicidal carboxylic acid is a compound of the formula 
       
         
           
           
               
               
           
         
       
       wherein Ar is a phenyl, pyridine, pyrimidine or quinoline group substituted with one or more substituents selected from halogen, C 1 -C 6  alkyl, C 1 -C 6  haloalkyl, C 1 -C 6  alkoxy, amino, C 1 -C 6  alkylamino, and di(C 1 -C 6  alkyl)amino. 
     
     
         10 . The herbicide delivery system of  claim 1 , wherein the herbicidal carboxylic acid is aminopyralid, aminocyclopyrachlor, clopyralid, dicamba, or picloram, and mixtures thereof. 
     
     
         11 . The herbicide delivery system of  claim 1 , wherein the weight ratio of the solid carrier to the herbicidal carboxylic acid, on an acid equivalent basis, ranges from about 1000:1 to about 10:1. 
     
     
         12 . The herbicide delivery system of  claim 1 , wherein the weight ratio of the solid carrier to the herbicidal carboxylic acid, on an acid equivalent basis, ranges from about 55:1 to about 40:1. 
     
     
         13 . A herbicide delivery system comprising:
 a solid carrier comprising from about 925 g/kg to about 975 g/kg of a solid carrier comprising limestone chips, the limestone chips having a hard inert surface and an irregular shape; and   a mixture of herbicidal carboxylic acids comprising from about 10 g ae/kg to 30 g ae/kg of a picloram potassium salt and from about 0.1 g ae/kg to 1 g ae/kg of an aminopyralid potassium salt,   wherein the mixture of herbicidal carboxylic acids is coated onto the surface of the solid carrier and the coated solid carrier is free flowing and does not cake during storage.   
     
     
         14 . The herbicide delivery system of  claim 13 , wherein greater than about 80% of the chips having a particle size within a range from about 400 microns (μm) to about 1200 μm. 
     
     
         15 . A method of preparing the herbicide delivery system of  claim 1  comprising:
 (a) preparing an aqueous solution of the potassium salt of the herbicidal carboxylic acid; 
 (b) spraying the aqueous solution of the potassium salt of the herbicidal carboxylic acid onto a granular solid carrier; and 
 (c) drying the resulting sprayed granular solid carrier to provide the herbicide delivery system as non-sticky, free-flowing granules.