Appeal No. 96-2898
Application No. 08/340,998
lubricating oil such as a naphthenic lube oil. The additive
composition is comprised of two polymers; an esterified
styrene-maleic anhydride copolymer (SMA) and an esterified
alpha-olefin maleic anhydride copolymer (OMA). In a blended
combination in lube oils, the two copolymers are said to
provide an unexpected synergistic effect with respect to pour
point reduction of the lubricating oil when compared to the
pour point reduction effected by either copolymer used alone.
By way of background, appellants acknowledge that two
problems encountered with hydrocarbon lubricating oils are
visible wax particles and the need for pour point improvement
(specification, page 2, lines 6 and 7). Appellants further
state at page 2, lines 7-14 that
[W]ax particles in lubricating oils can
cause blockage of filters and delivery
lines on equipment and engines, thus
interfering with the flow of oil to moving
parts. Wax particles in lubricating oils
also cause the oil to look hazy. This is
especially a problem in those oils such as
automotive oils, turbine oils and the like
which are desirably bright and clear in
appearance at room temperature. These oils
typically include fractions taken from
paraffinic or naphthenic crude oils or
crude oil blends from Pennsylvania, Mid-
Continent, Gulf Coast and West Coast
regions.
3
Page: Previous 1 2 3 4 5 6 7 8 9 Next
Last modified: November 3, 2007