Aqueous pour point depressant dispersion composition

Abstract

The present invention relates to an aqueous pour point depressant dispersion composition comprising a thermoplastic polymer, preferably ethylene vinyl acetate (EVA); a dispersing agent; water; optionally an aqueous freezing point depressant; and optionally a stabilizing agent wherein the volume average particle size of the dispersed thermoplastic polymer is equal to or less than 1 micrometers and a method to make and use said composition.

1 . An aqueous pour point depressant dispersion composition comprising:
 i ethylene vinyl acetate copolymer (EVA) in an amount of from 12 to 50 weight percent;   ii a dispersing agent in an amount of from 1 to 10 weight percent;   iii water;   and   iv optionally an aqueous freezing point depressant,   
       wherein weight percents are based on the total weight of the aqueous pour point depressant dispersion composition. 
     
     
         2 . The aqueous pour point depressant dispersion composition of  claim 1  wherein the average particle size of the dispersed EVA is equal to or less than 1 micrometer, the amount of dispersing agent in the final composition is from 1 to 10 weight percent, and the water:aqueous freezing point depressant mixture in the final composition is present in an amount of from 40 to 75 weight percent, the water:aqueous freezing point depressant ratio is from 40:60 to 70:30. 
     
     
         3 . The aqueous pour point depressant dispersion composition of  claim 1  further comprising:
 v a stabilizing agent in an amount of from 0.5 weight percent to 5 weight percent. 
 
     
     
         4 . The aqueous pour point depressant dispersion composition of  claim 1  wherein the polymer i is an ethylene vinyl acetate copolymer with 28 to 32 weight percent vinyl acetate, and a melt index (determined according to ASTM D1238 at 190° C. and 2.16 kg) of 43 g/10 min. 
     
     
         5 . The aqueous pour point depressant dispersion composition of  claim 1  wherein the polymer i is an ethylene vinyl acetate copolymer with 40 weight percent vinyl acetate, and a melt index (determined according to ASTM D1238 at 190° C. and 2.16 kg) of 52 g/10 min. 
     
     
         6 . The aqueous pour point depressant dispersion composition of  claim 1  wherein the dispersing agent ii comprises one or more of:
 a a fatty acid/salt having the formula R 1 COOR 2  wherein R 1  is a straight chain, saturated or unsaturated, hydrocarbon radical of 8 to 25 carbon atoms and R 2  is H or a base-forming radical; 
 b an alkyl, arene and/or alkylarene sulfonate; 
 c a salt of a polymer of alkyl acrylate and/or alkyl methacrylate and acrylic and/or methacrylic acid, or a salt of partial esters of maleic anhydride-styrene copolymers; 
 d a cationic surfactant; 
 e a zwitterionic surfactant; 
 or 
 f a nonionic surfactant. 
 
     
     
         7 . The aqueous pour point depressant dispersion composition of  claim 1  wherein the dispersing agent ii is a sodium salt of oleic acid, stearic acid, behenic acid or euric acid or a potassium salt of oleic acid, stearic acid, behenic acid or euric acid, or mixtures thereof. 
     
     
         8 . The aqueous pour point depressant dispersion composition of  claim 1  wherein the stabilizing agent v is a polyethoxylated nonionic surfactant; a polyvinyl alcohol; or an ionomer of an ethylene acrylic acid copolymer, an ethylene methacrylic acid copolymer, a polyacrylic acid polymer, a polyacrylic acid co-polymer, or an acrylic and urethane co-polymer. 
     
     
         9 . The aqueous pour point depressant dispersion composition of  claim 1  wherein the aqueous freezing point depressant is sodium chloride, potassium chloride, calcium chloride, methanol, ethanol, propanol, ethylene glycol, propylene glycol, glycerine, ethyl ether of ethylene glycol, propyl ether of ethylene glycol, butyl ether of ethylene glycol, hexyl ether of ethylene glycol, diethylene glycol, or propylene glycol. 
     
     
         10 . The aqueous pour point depressant dispersion composition of  claim 1  further comprising an additional additive vi selected from a biocide, a colorant, an anti-foaming agent, or a mixture thereof. 
     
     
         11 . A method of inhibiting the deposition of paraffin and/or improving the flow properties of oil comprising adding to the oil an effective amount of the pour point depressant composition of  claim 1 .