Wetting of water repellent soil by low HLB EO/PO block copolymers and enhancing solubility of same

Abstract

Water repellent soil is treated with low concentrations of EO/PO block copolymer having an HLB value of less than or equal to 2; an average molecular weight of greater than 3,000; and a percent hydrophile of 10 in order to rapidly increase the wetting rate of the water repellent soil.

What is claimed is:  
     
         1 . A process for increasing the wetting rate of water repellent soil which comprises the steps of: 
 i) preparing an aqueous wetting agent composition comprising 
 a) an ethylene oxide-propylene oxide block copolymer wherein the copolymer has an HLB value of less than or equal to 2; an average molecular weight of greater than 3,000; and a percent hydrophile of less than or equal to 10; and  
 b) water; and  
   ii) intimately contacting water repellent soil with an effective amount of said wetting agent composition.    
     
     
         2 . The process of  claim 1  wherein the total concentration of the block copolymer in the wetting agent composition is from 200,000 ppm to 2 ppm.  
     
     
         3 . The process of  claim 1  wherein the ethylene oxide-propylene oxide block copolymer is selected from the group consisting of: 
 i) straight block polymeric glycols obtained by the addition of ethylene oxide (EO) on a condensation product of propylene oxide (PO) with propylene glycol;  
 ii) reverse block polymeric glycols obtained by the addition of propylene oxide (PO) on a condensation product of ethylene oxide (EO) with ethylene glycol;  
 iii) tetra functional block copolymers obtained by the sequential addition of initially propylene oxide and then ethylene oxide to ethylene diamine; and  
 iv) tetra functional reverse block copolymers obtained by the sequential addition of initially ethylene oxide and then propylene oxide to ethylene diamine.  
 
     
     
         4 . The process of  claim 1  wherein the composition additionally comprises an ethylene-propylene oxide block copolymer having an HLB value greater than 2 and an average molecular weight of from 2,000 to 8,000.  
     
     
         5 . The process of  claim 1  wherein the composition additionally comprises an alkyl polyglycoside.  
     
     
         6 . The process of  claim 4  wherein the composition additionally comprises an alkyl polyglycoside.  
     
     
         7 . A process for increasing the wetting rate of water repellent soil which comprises the steps of: 
 i) preparing a solid granular or powder wetting agent composition containing an ethylene oxide-propylene oxide block copolymer wherein the copolymer has an HLB value of less than or equal to 2; an average molecular weight of greater than 3,000; and a percent hydrophile of less than or equal to 10; and    ii) contacting water repellent soil with an effective amount of said solid wetting agent composition.    
     
     
         8 . A process for increasing the wetting rate of water repellent soil which comprises the steps of: 
 i) preparing a solid granular or powder wetting agent composition containing an ethylene oxide-propylene oxide block copolymer wherein the copolymer has an HLB value of less than or equal to 2; an average mnoleciilar weight of greater than 3,000; and a percent hydrophile of less than or equal to 10;    ii) adding said solid wetting agent composition to water to form an aqueous wetting agent composition; and    iii) intimately contacting water repellent soil with an effective amount of said aqueous wetting agent composition.