Hydrocarbon solvent stable aqueous pour point depressant dispersion composition

Abstract

The present invention relates to an aqueous pour point depressant dispersion composition comprising an ethylene vinyl acetate copolymer (EVA); a dispersing agent; a polyethoxylated nonionic surfactant, a low level of hydrocarbon solvent, water; optionally one or more of an aqueous freezing point depressant, a stabilizing agent, or a basic metal substance and a method to use said composition.

What is claimed is: 
     
         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) a polyethoxylated nonionic surfactant;   (iv) water;   (v) a hydrocarbon solvent in an amount up to 50 weight percent;   and   (vi) 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:
 (vii) 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 18 to 32 weight percent vinyl acetate and a melt index of 43 g/10 min determined according to ASTM D1238 at 190° C. and 2.16 kg. 
     
     
         5 . The aqueous pour point depressant dispersion composition of  claim 1  wherein the polymer (i) is an ethylene vinyl acetate copolymer with 32 weight percent vinyl acetate and a melt index of 43 g/10 min determined according to ASTM D1238 at 190° C. and 2.16 kg. 
     
     
         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 or potassium 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 polyethoxylated nonionic surfactant (iii) is a primary alcohol ethoxylate, a branched secondary alcohol ethoxylate, a secondary alcohol ethoxylate, an ethylene oxide/propylene oxide copolymer, an alkyl polyglucoside, a nonylphenol ethoxylate, an octylphenol ethoxylate, or an alkoxylate. 
     
     
         9 . The aqueous pour point depressant dispersion composition of  claim 3  wherein the stabilizing agent (vii) is 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. 
     
     
         10 . The aqueous pour point depressant dispersion composition of  claim 1  comprising one or more of an aqueous freezing point depressant selected from 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. 
     
     
         11 . The aqueous pour point depressant dispersion composition of  claim 1  further comprising an additional additive (viii) selected from a biocide, a colorant, an anti-foaming agent, or a mixture thereof. 
     
     
         12 . The aqueous pour point depressant dispersion composition of  claim 1  further comprising (ix) one or more basic metal substance. 
     
     
         13 . 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 .