Preparation of emulsions by pH adjustments

Abstract

The present invention provides a water-in-oil explosive emulsion comprised of a continuous oil phase; a discontinuous aqueous phase containing a functional component and an emulsifying amount of a hydrocarbyl-substituted carboxylic acid or anhydride or ester or another derivation of said acid or anhydride; where the pH of the aqueous phase has been adjusted to a pH of at least 6.0 by the addition of a base other than the functional component. It has been discovered that the adjustment of the pH of the aqueous phase to a pH of at least 6.0 results in a considerably stable emulsion, even when the hydrocarbyl-substituted emulsifier is not aminated. A further stabilization of the emulsion can be accomplished through the use of sensitizing agents such as microspheres in order to ease handling and repumping of the explosive emulsion.

What is claimed is:  
     
         1 . A water-in-oil emulsion comprising: 
 a continuous oil phase;    a discontinuous aqueous phase containing a functional component; and    an emulsifying amount of a hydrocarbyl-substituted carboxylic acid or anhydride or ester or derivative of said acid or anhydride;    where the pH of the aqueous phase has been adjusted to a pH of at least 6.0 by the addition of a base other than the functional component.    
     
     
         2 . The water-in-oil emulsion of  claim 1 , wherein the hydrocarbyl-substituted compound is an anhydride.  
     
     
         3 . The water-in-oil emulsion of  claim 2 , wherein the anhydride is polyisobutenyl succinic anhydride.  
     
     
         4 . The water-in-oil emulsion of  claim 1 , wherein the hydrocarbyl-substituted compound is aminated.  
     
     
         5 . The water-in-oil emulsion of  claim 1 , wherein the base used to adjust the pH is comprised of ammonium hydroxide, calcium hydroxide, potassium hydroxide, sodium hydroxide, or ammonia.  
     
     
         6 . The water-in-oil emulsion of  claim 1 , wherein the adjusted pH level is in the range from 6.0-8.0.  
     
     
         7 . The water-in-oil emulsion of  claim 1 , wherein the adjusted pH is in the range of from 6.0-7.0.  
     
     
         8 . The water-in-oil emulsion of  claim 1 , wherein the adjusted pH is in the range of from 6.0-6.2.  
     
     
         9 . The water-in-oil emulsion of  claim 1 , wherein the functional component is ammonium nitrate.  
     
     
         10 . The explosive emulsion of  claim 1 , wherein the emulsion is further sensitized.  
     
     
         11 . The explosive emulsion of  claim 10 , wherein the emulsion comprises microspheres.  
     
     
         12 . A method for preparing a water-in-oil emulsion comprising a continuous oil phase and a discontinuous aqueous phase which comprises: 
 preparing a continuous oil phase;    preparing a discontinuous aqueous phase having a functional component therein,    adjusting the pH of the aqueous phase by the addition of a base other than the functional component; and    emulsifying the aqueous phase into the continuous oil phase using an emulsifying amount of a hydrocarbyl-substituted carboxylic acid or anhydride or ester or derivative of said acid or anhydride.    
     
     
         13 . The method of  claim 12 , wherein the hydrocarbyl-substituted compound is an anhydride.  
     
     
         14 . The method of  claim 13 , wherein the anhydride is polyisobutylene succinic anhydride.  
     
     
         15 . The method of  claim 12 , wherein the hydrocarbyl-substituted compound is aminated.  
     
     
         16 . The water-in-oil emulsion of  claim 12 , wherein the base used to adjust the pH is ammonium hydroxide, calcium hydroxide, potassium hydroxide, sodium hydroxide, or ammonia.  
     
     
         17 . The water-in-oil emulsion of  claim 16 , where in the pH adjustment is to a pH level of at least 6.0.  
     
     
         18 . The method of  claim 17 , wherein the pH adjustment is to a pH in the range of from 6.0 to 8.0.  
     
     
         19 . The method of  claim 17 , wherein the pH adjustment is to a pH in the range of from 6.0 to 7.0.  
     
     
         20 . The method of  claim 17 , wherein the pH adjustment is to a pH in the range of from 6.0 to 6.2.  
     
     
         21 . The method of  claim 12 , wherein the aqueous phase comprises ammonium nitrate as an oxidizer salt.  
     
     
         22 . The method of  claim 12 , wherein a sensitizing component is mixed into the emulsion.  
     
     
         23 . The method of  claim 23 , wherein the sensitizing component comprises microspheres.