Shear-Stable Oil Compositions and Processes for Making the Same
AssigneeExxonMobil Chemical Patents Inc.
InventorsWenning W. Han, Bernie J. Pafford
Life of this patent
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Abstract
An oil composition comprising a first component having pendant groups, a second component having two or more terminal carbon chains, and optionally a third component, where a single molecule of the second component can form shearable stable structure with two molecules of the first component via van der Waals force between pendant groups and the terminal carbon chains. Shear stability of the oil can be improved if the total concentration of the heavy fraction of the shearable stable structure is controlled at a low concentration.
Claims25
An oil composition comprising a first component and a second component different from the first component, wherein:
- the first component is a base stock comprising multiple molecules of a first type each having multiple pendant groups, where (i) the average pendant group length of the longest 5%, by mole, of the pendant groups of all of the molecules of the first type have an average pendant group length of Lpg(5%), where Lpg(5%)≧5.0;
- and (ii) a portion of the molecules of the first type have a number-average molecular weight greater than or equal to 20,000;
- the second component comprises multiple molecules of a second type each comprising two terminal carbon chains, where (i) the number-average molecular weight of the second component is no greater than 2,000;
- and (ii) the two terminal carbon chains have chain lengths equal to or greater than 5.0 and do not share a common carbon atom;
- a single molecule of the second type is capable of adjoining two molecules of the first type via van der Waals force between the pendant groups of the molecules of the first type and the two terminal carbon chains in the single molecule of the second type to form a first complex structure, the first complex structures comprising a first heavy fraction thereof having an equivalent number-average molecular weight of at least 45,000;
- the total maximum theoretical concentration of the first heavy fraction of the first complex structure, based on the total weight of the first component and the second component, is C11(max) wt %;
- and
- C11(max)≦20.
A process for forming an oil composition having a high shear stability performance, comprising the following steps:
- (I) providing a first component comprising multiple molecules of the first type each having multiple pendant groups, where the average pendant group length of the longest 5%, by mole, of the pendant groups of all of the molecules of the first type have an average pendant group length of Lpg(5%), where Lpg(5%)≧5.0;
- (II) providing a second component comprising multiple molecules of the second type each comprising at least two terminal carbon chains that do not share a common carbon atom, wherein at least two of the terminal carbon chains have chain lengths equal to or greater than 5.0;
- a single molecule of the second type is capable of adjoining two molecules of the first type via van der Waals force to form a first complex structure, the first complex structures comprising a first heavy fraction thereof having equivalent number-average molecular weight of at least 45,000;
- and
- (III) mixing the first component in a first quantity and the second component in a second quantity such that the total maximum theoretical concentration of the first heavy fraction of the first complex structure, based on the total weight of the first component and the second component, is C11(max) wt %;
- and
- C11(max)≦20.
Dependencies are inferred from the claim text.