SOLVENT DEWAXING WAXY HYDROCARBON OIL DISTILLATES USING A COMBINATION POLY DI-ALKYL FUMARATE-VINYL ACETATE COPOLYMER HAVING PENDENT CARBON SIDE CHAIN LENGTH OF PREDOMINANTLY C.SUB.2.SUB.2 AND POLYALKYL(METH-)ACRYLATE POLYMER DEWAXING ACID

摘要

ABSTRACT OF THE DISCLOSUREThis invention relates to processes forsolvent dewaxing waxy hydrocarbon oil distillatesemploying a dewaxing aid which dewaxing aid is a mixtureof (a) poly(meth-)acrylate polymers and (b) polydialkyl-fumarate/vinyl acetate copolymers. The dewaxing aidmixture is selected from the group of mixtures consist-ing of a mixture of (a) poly(meth-)acrylate polymerwhich is an ester of a C10 to C22 aliphatic alcoholwith acrylic or methacrylic acid and has a numberaverage molecular weight greater than about 5,000 and(b) polydialkylfumarate/vinyl acetate copolymer whereinthe pendent alkyl side chain group contains from 16-30carbon atoms but is primarily i.e. 50% C22 (prefer-ably behenyl), and the component (B) has a numberaverage molecular weight of about 1,000 to 100,000,preferably about 5,000 to 50,000. The combination (a)plus (b) may be employed in a weight ratio within therange of from about 100/1 to 1/100, preferably about 8/1to 1/4, more preferably about 8/1 to 1/1 most preferablyabout 3/1 a/b, and at an aid dose level ranging fromabout 0.01 to 1 wt.%, preferably between about 0.02to 0.2 wt.% active ingredient.The solvent dewaxing of bright stocks can alsobe benefitted by using as a dewaxing aid a combinationconsisting of component B recited above and a componentA which is a polymethacrylate copolymer having anaverage pendent carbon side chain length of predomi-nantly i.e. 50% C16 and higher.