Note: Descriptions are shown in the official language in which they were submitted.
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A LIQUID ~YDRDCARBON OIL CCMPOSITION CONTAINING
AN ESTER oF AN UNSATUR~IED CARBOXYLIC ACID
The invention is concerned with liquid hydrocarbon oil compositions
having improved resistance against the formation therein of insoluble material.
It is known that liquid hydrocarkon oils such as lubricating oils,
especially fuels, e.g. middle distillate fuels and hydrotreated lubricating oils
tend to form insoluble material during use especially at high temperatures e.g.
at temperatures of at least 100C. The Applicants have now found that esters
of olefinically unsaturated carboxylic acids reduce the amount of insoluble
material formed in liquid hydroc æbon oils.
Accordingly, the invention is concerned with a liquid hydrocarbon oil
ccmposition comprising a major proportion of a liquid hydrotreated hydrocarbon
oil and a minor proportion of a monomeric C8 to C50 hydrocarbyl ester of an
olefinically unsaturated cæboxylic acid.
The hydrocarbyl group of the ester is suitably an alkyl group, pre-
ferably a C10 to C30 alkyl group. The alkyl grDup may be lineæ or branched,
with substantially line æ alkyl groups being preferred. The hydroc æbyl group
may be substituted or interrupted e.g. with one or m~re halo-, oxy-, nitrogen-
or sulphu~-containing groups or atoms.
The esters may be derived from olefinically unsaturated monocæboxylic
acids i.e. acids having the general form~lla
. ~ :
,
~Z~ ,9
CnH2n-1CH'
and/or one or more olefinically unsaturated dicarboxylic acids such as fumaric
or maleic acid i.e. a~ids having the general formula:
CnH2n_2(cOoH)2
wherein, in both formwlae, n is an integer suitably of frc~n 2 to 10, preferably
of frc~n 2 to 6.
Preferred esters are those derived from olefinically unsaturated
monocar~oxylic acids, in particular those derived from acrylic and/or meth-
acrylic acids.
The preferred esters to be added to the hydrocarbon oil may be repre-
sented by the formula:
R
CH -CH-C-O-~
o
wherein R is H or a methyl group, and
Rl is a C8 to C50, preferably a C10 to C30, aLkyl group.
The esters may be prepared by any suitable technique such as by trans-
esterification but are suitably preFal-ed by direct esterification of the
appropriate acid with the appropriate alcohol. Suitable alcohols include
linear or branched and primary, secondary or tertiary alcDhols. A single
alcohol or a mixture of alcohols may be used. The alcohols may be natural or
synthetic e.g. hydroformylation alcohols.
The esters may be added to any liquid hydrocarbon oil. The liquid
hydrocarbon oil may be a synthetic or natural oil with mineral oils being
preferred. For example the esters may be added to crude mineral oil; lubricat-
ing oil; fuels e.g. heavy residual fuels and distillate fuels such as gasoline,
aviation turbine fuel and gas oil; and functional oils e.g. hydraulic oils,
heat transfer oils ancl automatic transmission fluids.
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The present invention is very useful for improving the resistance
of hydrotreated lubricating oils, particularly hydrocracked lubricating oils,
against the formation therein of insoluble material. In general, hydrocracking
is a severe hydrogenation treatment under conditions which depend upon the
nature of the oil but usually comprises corltacting the feedstock with hydrogen
in the presence of a hydrogenation catalyst at a temperature usually between
350 to 500C and at a press~reusually between 60 and 200 bars. Hydrocracking
is usually performed in place of a conventional solvent extraction step. Hydro~
cracking usually increases the viscosity index of the feedstock and is used in
the preparation of high, very high and extra high viscosity index lubricating
oils. The hydrocracked lubricating oils may be subjected to a hydrofinishing
step which is a mild hydrogenation step. The liquid hydrotreated hydrocarbon
oil may suitably be a hydrotreated middle distillate fuel, such as hydrotreated
products of middle distillate fuel, which usually have a boiling point range
of 120 to 480C at abmospheric pre OE e and which may be straight run products
or catalytically or thermally cracked products. Mixtures of such hydrotreated
fuels with non-hydrotreated fuels may also be used. These fuels may find
utility as heating, diesel or jet fuels.
The amount of ester present in the hydrwarbon oil oampositions may
vary ~etween wide limits e.g., frcm 0.001 to lO~ow~ preferably frcm 0.01 to
2.0 %w, based on the weight of the hydrocarbon oil.
The hydrocarbon oil composition may contain other additives such
as pour-point depressants, anti-corrosion
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.: ,, - . . .
.. ..~ : .. . -
- :. " ~ .~ .. .: . ~
3l~lZ~i'7~ ~
agents~ additi~e3 to improve the viscosity and vi~c08ity-
temperaturs oharacteristics, anti-oxidants, metal pa3~iva-
tors, extreme pressure and anti-wear additives.
~ he in~ention will now be illu~trated by reference to
the followin~ examples.
Exam~les 1 and 2
In these E~ample~ a liquid hydrocracked hydrocarbon
lubricating oil was used which was deri~ed from a crude
mineral oil. The lubricating oil has a VI of 94~5 and a
10 viscosity (98.9C) of 5.11 centistoke3. ~o the lubricatin~
oil ~88 added 1%w of either a C20/C22 (1:4) alkyl aorylate
(E~ample 1) or a C20/C22 (1:4) alkyl methacrylate (E~ample 2
The oil composition (30 ~) and the oil itself (30 ~;
E~ample a; ¢omparative) were tested by blowing air through
15 the mixture (15 litre~/hour) for 168 hours after which the
amount of i~soluble material formed wa3 determined. The
results obtained were 0.36%w (~xample 1), 0.33%w (3sample 2)
and 0.55%~ (~xample a).
Exam~les 3 and 4
In thi~ e~ample a liquid middle distillate fuel was
used having a boiling point range o~ from 150C to 300C.
The fuel was ~ubjected to the Jet Fuel O~idation and ~hermal
Stability Test (~S~M 3241). The fuel caused filter blockage
(pressure drop OVOE filter of more than 16,932 kPa) in
25 83 minutes. The test was tben repeated after addin8 0.02%
(32ample 3) and o.o306 (3xample 4) of a C20/C22 (1:4) alkyl
acrylate. The composition of Example 3 caused filter
blockage after 121 minutes and the composition of ~xample 4
had not caused filter blockage by the end of the test
(150 minutes) at which time the pressure drop over filter
was 1693.2 kPa.
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