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US 4,064,058 AGranted
Mixed synthetic ester grease base stock
AssigneeHercules Incorporated
InventorJohn F. Walker
Life of this patent
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AssigneeHercules Incorporated
InventorJohn F. Walker
Estimating the term…
Disclosed is a grease base stock characterized by outstanding thermal and oxidation stability, low volatility, and high viscosity index. It comprises a blend of (1) a normally liquid pentaerythritol ester product consisting essentially of pentaerythritol material selected from the group consisting of pentaerythritol and polypentaerythritols, completely esterified by C.sub.4 -C.sub.12 alkanoic acid material, and (2) a neopentyl glycol ester product having a substantially higher 77.degree. F. viscosity than the pentaerythritol ester product and consisting essentially of the reaction product of neopentyl glycol, C.sub.4 -C.sub.12 alkanedioic acid material and C.sub.4 -C.sub.12 alkanol material substantially at mole ratios of n:(n+1):2, n being a whole number in the range from 1 to 12. The weight ratio of the pentaerythritol ester product to the neopentyl glycol ester product is generally in a range from about 2:3 to about 9:1.
A composition of matter useful as grease base stock, which consists essentially of a blend of (1) a normally liquid pentaerythritol ester product and (2) a neopentyl glycol ester product, the weight ratio of said products being in a range from about 2:3 to about 9:1, said pentaerythritol ester product consisting essentially of pentaerythritol material fully esterified by C.sub.4 -C.sub.12 alkanoic acid material, said neopentyl glycol ester product having a substantially higher 77.degree. F. viscosity than said pentaerythritol ester product, and consisting essentially of the reaction product of neopentyl glycol, C.sub.4 -C.sub.12 alkanedioic acid material, and C.sub.4 -C.sub.12 alkanol material, the mole ratio of said glycol to said alkanedioic acid material to said alkanol material being substantially n:(n+1):2 with n being a whole number in the range from 1 to 12.
A process for making a grease base stock, which comprises blending (1) a normally liquid pentaerythritol ester product with (2) a neopentyl glycol ester product at a weight ratio of pentaerythritol ester product to said glycol ester product in a range from about 2:5 to about 9:1, said pentaerythritol ester product consisting essentially of pentaerythritol material fully esterified by C.sub.4 -C.sub.12 alkanoic acid material, said neopentyl glycol ester product having a substantially higher 77.degree. F. viscosity than said pentaerythritol ester product, and consisting essentially of the reaction product of neopentyl glycol, C.sub.4 -C.sub.12 alkanedioic acid material and C.sub.4 -C.sub.12 alkanol material, the mole ratio of said glycol to said alkanedioic material to said alkanol material being n:(n+1):2, n being a whole number in the range from 1 to 12.
A method of lubricating relatively movable surfaces, one of which bears on the other, which comprises applying to said surfaces a grease consisting essentially of a blend of (1) a normally liquid pentaerythritol ester product and (2) a neopentyl glycol ester product, the weight ratio of said products being in a range from about 2:3 to about 9:1, said pentaerythritol ester product consisting essentially of pentaerythritol material fully esterified by C.sub.4 -C.sub.12 alkanoic acid material, said neopentyl glycol ester product having a substantially higher 77.degree. F. viscosity than said pentaerythritol ester product, and consisting essentially of the reaction product of neopentyl glycol, C.sub.4 -C.sub.12 alkanedioic acid material and C.sub.4 -C.sub.12 alkanol material, the mole ratio of said glycol to said alkanedioic material to said alkanol material being n:(n+1):2, n being a whole number in the range from 1 to 12.
Dependencies are inferred from the claim text.