Terpolymers of ethylene, vinyl acetate, and styrene as pour point depressants for distillate fuels
AssigneeThe Dow Chemical Company
InventorNash A. Kidd
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Abstract
The flow properties of petroleum distillate fuel oils at low temperature are improved by adding a pour point depressant amount of certain terpolymers of ethylene, vinyl acetate and styrene, particularly characterized as having more uniform macromolecular composition and distribution of monomer constituent units polymerized in the terpolymer macromolecules, made by terpolymerization under steady state conditions and pressure at least 1000 atmospheres and temperature at least 200.degree. C.
Claims4
Pour point depressant terpolymers for middle distillate fuels, consisting essentially of from about 45 to about 75 percent ethylene, at least about 5 percent vinyl acetate, and at least about 5 percent styrene, by weight, and having melt flow rate as defined from about 1 to about 50 dg/min, particularly characterized in that the terpolymers are prepared by free-radical-initiated terpolymerization of ethylene, vinyl acetate and styrene under substantially steady state terpolymerization conditions of at least 1000 atmospheres pressure and temperature of at least 200.degree. C.
Dependencies are inferred from the claim text.