Polyalphaolefin & Fischer-Tropsch derived lubricant base oil lubricant blends

Abstract

Blended lubricant base oils and blended finished lubricants comprising ≧70 weight percent Fischer-Tropsch derived lubricant base oils comprising ≧6 weight % molecules with monocycloparaffinic functionality and less than 0.05 weight % molecules with aromatic functionality; at least one polyalphaolefin lubricant base oil with a kinematic viscosity at 100° C. greater than about 30 cSt and less than 150 cSt are provided. These blended lubricant base oils and blended finished lubricants exhibit superior friction and wear properties, in addition to other highly desired properties. Also provided are processes for making these blended lubricant base oils and blended finished lubricants.

Description

[0001] The present invention is directed to blended lubricants and blended finished lubricants comprising a Fischer-Tropsch derived lubricant base oil and at least one polyalphaolefin lubricant base oil and processes for making the same. The blended finished lubricants require surprisingly less anti-wear additives to achieve acceptable wear performance than required for Fisher-Tropsch derived lubricant base oils in the absence of at least one polyalphaolefin (PAO) lubricant base oil. BACKGROUND OF THE INVENTION [0002] High performance automotive and industrial lubricants are in demand. Accordingly, lubricant manufacturers must provide finished lubricants that exhibit high performance properties. To produce these finished lubricants lubricant manufacturers are seeking higher quality lubricant base oil blend stocks. Performance characteristics that are significant include additive solubility, deposit control, and lubricity. [0003] A growing source of these high quality lubricant base ...

AI Technical Summary

Benefits of technology

[0007] It has been discovered that the blended lubricant base oils and blended finished lubricants of the present invention, comprising Fischer-Tropsch derived lubricant base oils and polyalphaolefins, exhibit improved friction and wear properties with reduced amounts of anti-wear additives.

[0011] In yet another embodiment, the present invention relates to a method of reducing wear in ferrous alloy equipment. The method comprises lubricating the equipment with a blended finished lubricant comprising ≧70 weight percent Fischer-Tropsch derived lubricant base oil comprising ≧6 weight percent molecules with monocycloparaffinic functionality and less than 0.05 weight percent molecules with aromatic functionality, at least one polyalphaolefin lubricant base oil having a kinematic viscosity at 100° C. greater than about 30 cSt and less than 150 cSt; and an effective amount of at least one anti-wear additive; and operating the equipment after the lubricating.

Problems solved by technology

However, these lubricant base oils are expensive to produce.

Although Fischer-Tropsch derived lubricant base oils are desirable for their biodegradability and low amounts of undesirable impurities such as sulfur, the Fischer-Tropsch derived lubricants generally do not exhibit desirable wear performance, lubricity, and deposit performance.

Although it is well known in the art to improve these performance characteristics through the use of additives, these additives are generally expensive and thus, can significantly increase the cost of the lubricant base oil.

Antiwear additives often contain significant amounts of both sulfur and phosphorus.