Note: Descriptions are shown in the official language in which they were submitted.
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IMPROVED OIL COMPOSITION
This invention relates to improved detergent and lubricity additives for fuel
oils.
The art generally describes additives derived from hydrocarbyl-substituted
succinic
acylating agents (such as succinic anhydrides) and pofyalkylene polyamines.
These
materials are sometimes known as 'succinimides' or 'acylated nitrogen
dispersants'.
Particularly well-known are those materials wherein the succinic substituent
is derived
1o from polyisobutylene, the resulting materials being commonly known as
'PIBSA-PAM'
(Polyisobutylene-succinic anhydride-polyamine) products.
The trivial name of 'succinimides' is, for many of these products, rather an
oversimplification. The commercially-available materials used to make these
products are
typically complex mixtures rather than discrete compounds, and thus give rise
to a
complex mixture of other condensation products in addition to various imides.
EP-B-0 451 380 provides a broad general description of PIBSA-PAM products and
illustrates the complex nature of many polyamine mixtures. The examples are
restricted
2o to PIBSA-PAM products obtained from polyethylene tetramine or pentamine at
molar
ratios of 1.5:1 or greater (PIBSA:PAM).
With such variability in products produced from different sources of starting
materials,
there exists in the art a continual need for better understanding of the
molecular
parameters controlling various aspects of additive performance, and for better-
performing,
more cost-effective products.
Surprisingly, it has now been found that by selecting a certain mole ratio of
reactants and
certain polyamine characteristics, products having improved application
specifically in fuel
oils are obtained.
In a first aspect, the invention provides a fuel oil composition comprising a
fuel oil and a
minor proportion of an additive, wherein the additive comprises the product
obtainable by
the reaction between:
(i) a hydrocarbyl-substituted succinic acylating agent, wherein the
hydrocarbyl
substituent has a number-average molecular weight (Mn) of 250 to 2500,
and
CONFIRMATION COPY
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2
(ii) one or more polyalkylene polyamines,
characterised in that the polyamine component (ii) contains greater than 35%
by weight of
polyamines having more than six nitrogen atoms per molecule, based on the
total weight
of polyamines, and in that (i) and (ii) are reacted in a molar ratio in the
range of 1.4:1 to 1:1
((i):(i7).
In a second aspect, the invention provides the additive as defined under the
first aspect.
In a third aspect, the invention provides the use of the additive of the
second aspect as a
detergent and/or lubricity improver in a fuel oil.
When used in a fuel oil, and especially a middle distillate fuel oil, the
additive according to
}5 the invention provides surprisingly-improved fuel detergency, especially in
fuel oil systems
such as diesel fuel engines where improved fuel injector detergency is
observed. In
addition, the additive can provide lubricity improvement for fuel oils, a
property of
increasing usefulness especially in middle distillate fuels as incremental
legislative
changes force down the level of sulphur of such fuels, leading to fuel
processing and
compositional changes which reduce the fuels' inherent lubricity properties.
Such lubricity
enhancement is particularly effective in inhibiting wear in the fuel injection
pumps of diesel
engine systems which, due to engineering developments aimed at reducing
emissions,
are being designed to operate at increasingly high pressures and are therefore
more
prone to wear.
These improvements in performance are believed to result from the optimised
structure of
the product defined under the first aspect of the invention. Without being
bound to any
particular theory, it is thought that the combination in the product of a
polyalkylene
polyamine having a high proportion of heavy {i.e. higher molecular weight)
components,
3o and a relatively low average molar ratio of acyiating agent (i) to
polyamine (ii), gives rise to
products having a balance of polar and non-polar groups which is particularly
effective in
the fuel oil environment.
_.~ _ __ _ .._ _ . r ~ , t
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3
The First Aspect of the Invention
The product
The product is preferably obtained by the reaction of (i) and (ii) as above
defined.
(i) The hydrocarbyl-substituted succinic acylating agent
The term hydrocarbyl denotes a group having a carbon atom directly attached to
to the remainder of the molecule and which has a predominantly aliphatic
hydrocarbon character. Therefore, hydrocarbyl substituents can contain up to
one
non-hydrocarbyl group for every 10 carbon atoms provided that this non-
hydrocarbyl group does not significantly alter the predominantly aliphatic
hydrocarbon character of the group. Those skilled in the art will be aware of
such
groups, which include, for example, hydroxyl, halo (especially chloro and
fluoro),
alkoxyl, alkyl mercapto, alkyl sulfoxy, etc. Usually, however, the hydrocarbyl
substituents are purely aliphatic hydrocarbon in character and do not contain
such
groups.
2o The hydrocarbyl substituents are predominantly saturated. The hydrocarbyl
substituents are also predominantly aliphatic in nature, that is, they contain
no
more than one non-aliphatic moiety (cycloalkyl, cycioalkenyl or aromatic)
group of
6 or less carbon atoms for every 10 carbon atoms in the substituent. Usually,
however, the substituents contain no more than one such non-aliphatic group
for
every 50 carbon atoms, and in many cases, they contain no such non-aliphatic
groups at all; that is, the typically substituents are purely aliphatic.
Typically, these
purely aliphatic substituents are alkyl or alkenyl groups.
The hydrocarbyl substituents preferably average at least 30 to 50 and up to
about
100 carbon atoms, corresponding to an Mn of approximately 400 to 1500 such as
550 to 1500, and preferably 700 to 1500. An Mn of 700 to 1300 is preferred.
Specific examples of the predominantly saturated hydrocarbyl substituents
containing an average of more than 30 carbon atoms are the following: a
mixture
- 35 of poly(ethylenelpropylene) or poly(ethylenelbutene) groups of about 35
to about
70 carbon atoms; a mixture of poly(propylene/1-hexene) groups of about 80 to
about 100 carbon atoms; a mixture of pofy(isobutene) groups having an average
of
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50 to 75 carbon atoms; a mixture of poly (1-butene) groups having an average
of
50-75 carbon atoms.
A preferred source of the substituents are poly(isobutene)s, for examples
those
obtained by polymerization of a C4 refinery stream having a butene content of
35
to 75 weight per cent and isobutene content of 30 to 60 weight per cent in the
presence of a Lewis acid catalyst such as aluminium trichloride or boron
trifluoride.
These polybutenes predominantly contain isobutene monomer repeating units of
the configuration
-C(CH3)2CH2_
The hydrocarbyi substituent is attached to the succinic acid moiety or
derivative
thereof via conventional means, for example the reaction between malefic
anhydride and an unsaturated substituent precursor such as a polyalkene, as
described for example in EP-B-0 451 380.
One procedure for preparing the substituted succinic acylating agents involves
first
chlorinating the polyalkene until there is an average of at least about one
chloro
2o group for each molecule of polyalkene. Chforination involves merely
contacting the
polyalkene with chlorine gas until the desired amount of chlorine is
incorporated
into the chlorinated polyalkene. Chlorination is generally carried out at a
temperature of about 75°C to about 125°C. If desired, a diluent
can be used in the
chlorination procedure. Suitable diluents far this purpose include poly- and
perchlorinated andlor fluorinated alkanes and benzenes.
The second step in the procedure is to react the chlorinated polyalkene with
the
malefic reactant at a temperature usually within the range of about
100°C to about
200°C. The mole ratio of chlorinated poiyalkene to malefic reactant is
usually about
1:1. However, a stoichiometric excess of malefic reactant can be used, for
example, a mole ratio of 1:2. If an average of more than about one chloro
group
per molecule of polyalkene is introduced during the chlorination step, then
more
than one mole of malefic reactant can react per molecule of chlorinated
polyalkene.
It is normally desirable to provide an excess of malefic reactant; for
example, an
excess of about 5% to about 25% by weight. Unreacted excess malefic reactant
may be stripped from the reaction product, usually under vacuum.
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Another procedure for preparing substituted succinic acid acylating agents
utilises
a process described in U.S. Pat. No. 3,912,764 and U.K. Pat. No. 1,440,219.
According to that process, the polyalkene and the malefic reactant are first
reacted
by heating them together in a direct alkylation procedure. When the direct
5 alkylation step is completed, chlorine is introduced into the reaction
mixture to
promote reaction of the remaining unreacted malefic reactants. According to
the
patents, 0.3 to 2 or more moles of malefic anhydride are used in the reaction
for
each mole of polyalkene. The direct alkylation step is conducted at
temperatures
to 180°C to 250°C. During the chlorine-introducing stage, a
temperature of 160°C
~o to 225°C is employed.
Other known processes for preparing the substituted succinic acylating agents
include the one-step process described in U.S. Pat. Nos. 3,215,707 and
3,231,587.
Basically, this process involves preparing a mixture of the polyalkene and the
~5 malefic reactant in suitable proportions and introducing chlorine into the
mixture,
usually by passing chlorine gas through the mixture with agitation, while
maintaining a temperature of at least about 140°C.
Usually, where the polyalkene is sufficiently fluid at 140°C and above,
there is no
2o need to utilise an additional substantially inert, normally liquid
soiventldiluent in the
one-step process. However, if a solventldiluent is employed, it is preferably
one
that resists chforination such as the poly- and per-chlorinated and/or -
fluorinated
alkanes, cycloalkanes, and benzenes.
25 Chlorine may be introduced continuously or intermittently during the one-
step
process. The rate of introduction of the chlorine is not critical although,
for
maximum utilisation of the chlorine, the rate should be about the same as the
rate
of consumption of chlorine in the course of the reaction. When the
introduction
rate of chlorine exceeds the rate of consumption, chlorine is evolved from the
3o reaction mixture. It is often advantageous to use a closed system,
including
superatmospheric pressure, in order to prevent loss of chlorine so as to
maximize
chlorine utilisation.
The minimum temperature at which the reaction in the one-step process takes
35 place at a reasonable rate is about 140°C. Thus, the minimum
temperature at
which the process is normally carried out is in the neighbourhood of
140°C. The
preferred temperature range is usually between about 160°C and about
220°C.
Higher temperatures such as 250°C or even higher may be used but
usually with
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little advantage. In fact, excessively high temperatures may be
disadvantageous
because of the possibility that thermal degradation of either or both of the
reactants
may occur at excessively high temperatures.
In the one-step process, the molar ratio of maieic reactant to chlorine is
such that
there is at least about one mole of chlorine for each mole of malefic reactant
to be
incorporated into the product. Moreover, for practical reasons, a slight
excess,
usually in the neighbourhood of about 5% to about 30% by weight of chlorine,
is
utilised in order to offset any loss of chlorine from the reaction mixture.
Larger
amounts of excess chlorine may be used.
The attachment of the hydrocarbyl substituent to the succinic moiety may
alternatively be achieved via the thermally-driven 'ene' reaction, in the
absence of
chlorine. Use of such a material is the acylating agent (i) leads to products
having
particular advantages; for example, chlorine-free products having excellent
detergency and lubricity properties. in such products, the reactant (i) is
preferably
formed from a polyalkene having at least 30% preferably 50% or more such as
75% of residual unsaturation in the form of terminal, e.g. vinylidene, double
bonds.
(ii) The polyalkylene polyamine
The polyamines suitable in this invention are those comprising amino nitrogens
linked by alkylene bridges, which amino nitrogens may be primary, secondary
andlor tertiary in nature. The polyamines may be straight chain, wherein all
the
amino groups will be primary or secondary groups, or may contain cyclic or
branched regions or both, in which case tertiary amino groups may also be
present. The alkylene groups are preferably ethylene or propylene groups, with
ethylene being preferred. Such materials may be prepared from the
polymerisation of lower alkylene diamines such as ethylene diamine, a mixture
of
3o polyamines being obtained, or via the reaction of dichloroethane and
ammonia.
The present invention has discovered that the nature of the polyamine, and in
particular the relative proportions of different polyamines within a polyamine
mixture, has an important bearing on the performance of the product defined
under
the invention. It is preferred that where the polyamine component (ii) is a
mixture,
the mixture contains at least 70%, and preferably at least 75% by weight, of
polyamines having seven or more nitrogen atoms per molecule, based on the
total
weight of polyamines.
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Preferably, the mixture comprises polyamines having seven and eight, and
optionally nine, nitrogen atoms per molecule.
s More preferably, the polyamine mixture comprises at least 45% and preferably
50% by weight of poiyamines having seven nitrogen atoms per molecule, based on
the total weight of polyamines.
The polyamine component (ii) may be defined by the average number of nitrogen
1o atoms per molecule of the component (ii), which is preferably in the range
of 6.5 to
8.5, more preferably 6.8 to 8, especially 6.8 to 7.5 nitrogens per molecule.
The
number of nitrogens appears to influence the ability of the product to provide
fuel
oil detergency and lubricity enhancement, especially in middle distillate fuel
oils
such as diesel fuel where good injector detergency is exhibited in both 'keep
clean'
15 and 'clean-up' tests.
The reaction of polyamine (ii) with the acylating agent (i} is carried out in
the
appropriate ratio, as above defined. Preferably, the molar ratio of (i):(ii)
is in the
range of 1.35:1 to 1.05:1, more preferably 1.3:1 to 1.15:1, and most
preferably
20 1.25:1 to 1.15:1. For this purpose, the molar quantity of (i) refers to the
molar
quantity of pibsa farmed during the reaction procedure as previously
described,
and does not typically refer to the total molar quantity of pib found in the
pibsa
reactant (i) which may be higher if unreacted pib remains from the pibsa
formation
reaction. The molar quantity of pibsa is typically determined by titration,
e.g. via
25 saponification of the reacted malefic anhydride moieties. The specific
mixture of
individual reaction products obtained by operating within such ratios has been
found to be particularly useful for fuel oil applications, especially middle
distillate
fuel oil applications.
3o The reaction is typically carried out at conventional temperatures in the
range of
about 80°C to about 200°C, more preferably about 140°C to
about 180°C. These
reactions may be conducted in the presence or absence of an ancillary diluent
or
liquid reaction medium, such as a mineral oil or aromatic solvent. If the
reaction is
conducted in the absence of an ancillary solvent of this type, such is usually
added
35 to the reaction product on completion of the reaction. In this way the
final product
is in the form of a convenient solution and thus is compatible with an oil.
Suitable
solvent oils are oils used as a lubricating oil basestock, and these generally
include
lubricating oils having a viscosity (ASTM D 445) of 2 to 40, preferably 3 to
12
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8
mm2/sec at 100°C, with the primarily paraffinic mineral oils, such as
those in the
range of Solvent 90 to Solvent 150 Neutral, being preferred.
More preferred are aromatic solvents which give rise to particularly low
viscosity
products and result in products having surprisingly advantageous compatibility
when blended with other components fn the additive. Advantageous solvents
include xylenes, trimethylbenzene, ethyl toluene, diethylbenzene, cymenes,
amylbenzene, diisopropyl benzene, or mixtures thereof, optionally with
isoparaffins. Products obtained via reaction in such solvents can be blended
to
1o form particularly homogeneous additives containing other additive
components.
Tha ArirlifiivA
~5 The additives of the invention may be used singly or as mixtures. They may
contain one
or more co-additives such as known in the art, for example the following:
detergents,
antioxidants, corrosion inhibitors, dehazers, demulsifiers, metal
deactivators, antifoaming
agents, cetane improvers, cosolvents, package compatibilisers, lubricity
additives,
antistatic additives and cold flow additives.
Concentrates comprising the additive in admixture with a carrier liquid (e.g.
as a solution
or a dispersion) are convenient as a means for incorporating the additive into
bulk oil such
as distillate fuel, which incorporation may be done by methods known in the
art. The
concentrates may also contain other additives as required and preferably
contain from 3 to
75 wt%, more preferably 3 to 60 wt%, most preferably 10 to 50 wt% of the
additives
preferably in solution. Examples of carrier liquid are organic solvents
including
hydrocarbon solvents, for example petroleum fractions such as naphtha,
kerosene, diesel
and heater oil; aromatic hydrocarbons such as aromatic fractions, e.g_ those
sold under
the 'SOLVESSO' tradename; alcohols, ethers and other oxygenates and paraffinic
3o hydrocarbons such as hexane and pentane and isoparaffins. The carrier
liquid must, of
course, be selected having regard to its compatibility with the additive and
with the fuel.
The additives of the invention may be incorporated into fuel oil by other
methods such as
those known in the art. If co-additives are required, they may be incorporated
into the fuel
oil at the same time as the additives of the invention or at a different time.
y. . . ~._....~... _ ...~.... _._ __ ~. r ~ , T
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ThA F~ ~Pi nn
The fuel oil may be a hydrocarbon fuel such as a petroleum-based fuel oil for
example
gasoline, kerosene or distillate fuel oil, suitably a middle distillate fuel
oil, i.e. a fuel oil
' obtained in refining crude oil as the fraction between the lighter kerosene
and jet fuels
fraction and the heavier fuel oil fraction. Such distillate fuel oils
generally boil within the
range of about 100°C to about 500°C, e.g. 150° to about
400°C, for example, those having
a relatively high Final Boiling Point of above 360°C (ASTM D-86).
Middle distillates
1o contain a spread of hydrocarbons boiling over a temperature range,
including n-alkanes
which precipitate as wax as the fuel cools. They may be characterised by the
temperatures at which various %'s of fuel have vaporised, e.g. 10% to 90%,
being the
interim temperatures at which a certain volume % of initial fuel has
distilled. The
difference between say 90% and 20% distillation temperature may be
significant. They
are also characterised by pour, cloud and CFPP points, as well as their
initial boiling point
(IBP) and final boiling point (FBP). The fuel oil can comprise atmospheric
distillate or
vacuum distillate, or cracked gas oil or a blend in any proportion of straight
run and
thermally and/or catalytically cracked distillates. The most common petroleum
distillate
fuels are kerosene, jet fuels, diesel fuels, heating oils and heavy fuel oils.
The heating oil
or diesel fuel may be a straight atmospheric distillate, or it may contain
minor amounts,
e.g. up to 35 wt%, of vacuum gas oil or cracked gas oils or of both.
Heating oils may be made of a blend of virgin distillate, e.g. gas oil,
naphtha, etc and
cracked distillates, e.g. catalytic cycle shock. A representative
specification for a diesel
fuel includes a minimum flash point of 38°C and a 90% distillation
point between 282 and
380°C (see ASTM Designations D-396 and D-975).
The fuel oil may also contain other additives such as stabilisers,
dispersants, antioxidants,
corrosion inhibitors and/or demulsifiers.
3U
The fuel oil may have a sulphur concentration of 0.2% by weight or less based
on the
weight of the fuel. Preferably, the sulphur concentration is 0.05% by weight
or less, such
as 0.035% by weight or less, more preferably 0.01 % by weight or less. The art
describes
methods for reducing the sulphur concentration of hydrocarbon middle
distillate fuels, such
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methods including solvent extraction, sulphuric acid treatment, and
hydrodesulphurisation.
The additive of the invention is particularly advantageous in the fuels having
low sulphur
contents, providing excellent lubricity improvement and good detergency.
5 Also, the fuel oil may be an animal or vegetable oil, or a mineral oil as
described above in
combination with an animal or vegetable oil.
Biofuels, i.e. fuels from animal or vegetable sources, are obtained from a
renewable
source. It has been reported that on combustion less carbon dioxide is formed
than is
to formed by the equivalent quantity of petroleum distillate fuel, e.g. diesel
fuel, and very little
sulphur dioxide is formed. Certain derivatives of vegetable oil, for example
rapeseed oil,
e.g. those obtained by saponification and re-esterification with a monohydric
alcohol, may
be used as a substitute for diesel fuel. It has been reported that mixtures of
a rapeseed
ester, for example, rapeseed methyl ester (RME), with petroleum distillate
fuels in ratios
of, for example, 10:90 by volume are commercially available.
Thus, a biofuel is a vegetable or animal oil or both or a derivative thereof.
Vegetable oils are mainly triglycerides of monocarboxylic acids, e.g. acids
containing 10-
25 carbon atoms and listed below
CH20COR
CHOCOR
CH20COR
where R is an aliphatic radical of 10-25 carbon atoms which may be saturated
or
unsaturated.
Generally, such oils contain glycerides of a number of acids, the number and
kind varying
with the source vegetable of the oil.
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Examples of oils are rapeseed oil, tall oil, coriander oil, soyabean oil,
cottonseed oil,
sunflower oil, castor oil, olive oil, peanut oil, maize oil, almond oil, palm
kernel oil, coconut
oil, mustard seed oil, beef tallow and fish oils. Rapeseed oil, which is a
mixture of fatty
acids esterified with glycerol, is preferred as it is available in large
quantities and can be
obtained in a simple way by pressing from rapeseed.
Examples of derivatives thereof are alkyl esters, such as methyl esters, of
fatty acids of
the vegetable or animal oils. Such esters can be made by transesterification.
to As lower alkyl esters of fatty acids, consideration~may be given to the
following, for
example as commercial mixtures: the ethyl, propyl, butyl and especially methyl
esters of
fatty acids with 12 to 22 carbon atoms, for example of lauric acid, myristic
acid, palmitic
acid, palmitoleic acid, stearic acid, oleic acid, elaidic acid, petroselic
acid, ricinoleic acid,
elaeostearic acid, linoleic acid, finolenic acid, eicosanoic acid, gadoleic
acid, docosanoic
~ 5 acid or erucic acid, which have an iodine number from 50 to 210,
especially 90 to 180.
Mixtures with particularly advantageous properties are those which contain
mainly, i.e. to
at least 50 wt% methyl esters of fatty acids with 16 to 22 carbon atoms and
may contain 1,
2 or 3 double bonds. The preferred lower alkyl esters of fatty acids are the
methyl esters
of oleic acid, linoleic acid, linoienic acid and erucic acid.
Commercial mixtures of the stated kind are obtained for example by cleavage
and
esterification of natural fats and oils by their transesterification with
lower aliphatic
alcohols. For production of lower alkyl esters of fatty acids it is
advantageous to start from
fats and oils with high iodine number, such as, for example, sunflower oil,
rapeseed oil,
coriander oil, castor oil, soyabean oil, cottonseed oil, peanut oil or beef
tallow. Lower alkyl
esters of fatty acids based on a new variety of rapeseed oil, the fatty acid
component of
which is derived to more than 80 wt% from unsaturated fatty acids with 18
carbon atoms,
are preferred.
3o The concentration of the additive in the fuel oil may for example be in the
range of 1 to
5,000 ppm of additive (active ingredient) by weight per weight of fuel, for
example 5 to
5,000 ppm such as 5 to 2000 ppm (active ingredient) by weight per weight of
fuel,
preferably 10 to 500 ppm, more preferably 10 to 200 ppm.
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Example 1
Additive A
A 60% active ingredient solution (in aromatic solvent) of a PIBSA-PAM product
obtained
from the condensation reaction of a chlorinated PIBSA (succinic anhydride)
derived from
polyisobutene of Mn approx. 950 with a polyethylene polyamine mixture
containing
approximately 84% by weight of polyamines containing more than six nitrogen
atoms, and
to predominating in seven and eight nitrogen molecules, in a molar ratio of
1.2:1
(PIBSA:PAM)_ The synthesis was carried out as follows:
The PiBSA (750g) and C9 aromatic Solvent (469.7g) were introduced into a
reaction flask
equipped with a nitrogen sparge. The mixture was heated to 155°C. PAM
(159.5g) was
added dropwise over 1 hour keeping the temperature around 1fi5°C. After
complete
addition, the temperature was set to 165°C and the mixture left to soak
for about 5 hours
(or until no more water was collected). The nitrogen sparge rate was increased
towards
the end of the reaction when the rate of water collection fell to a very low
rate.
Comparative Additive
A PIBSA-PAM product obtained from equivalent conditions with the same PIBSA,
but
using a molar ratio of 1.8:1 (P1BSA:PAM) and a polyethylene polyamine mixture
of
average composition approximating to pentaethylenehexamine and comprising
approximately 33.5% by weight of poiyamines having more than six nitrogen
atoms per
molecule, based on the total weight of polyamines. The solvent was mineral oil
(Solvent
Neutral 150) having a kinematic viscosity of 28.8 - 31.9 cSt at 40°C,
the active ingredient
level of the product being approx. 50% wt.
The diesel fuel detergency properties of Additive A and the Comparative
Additive were
tested using a test engine protocol (the 'Cummins L10') which provides an
assessment of
the degree of injector deposits resulting from engine operation on a reference
fuel. The
injector deposits can be measured by a rating of the deposit on each fuel
injector
according to a 'demerits' scale and also by measurement of the mean air flow
through a
..r. _._ . r .._~ . _.
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13
given set of fuel injectors before and after the test, the percentage loss in
air flow due to
deposit build-up during the test being recorded.
Figure 1 illustrates the results of various tests conducted in a low sulphur
reference diesel
fuel.
TEST METHOD RESULTS C
Distillation - IBP ASTM D86 196
5% 214
10% 221
20% 232
30% 242
40% 253
50% 264
60% 276
70% 288
80% 301
90% 317
95% 328
Distillation - EP 339
Gravity ASTM D4052 34.3
Pour Point ASTM D97 -21 C
Cloud Point ASTM D2500 -20C
Flash Point ASTM D93 81
Viscosity, 40C ASTM D445 2.7
Sulfur ASTM D4294 0.034
Aromatics by SFC D5186 29.6
Basic Sediment & Water ASTM D1796 <0.05
Ramsbottom carbon, 10% ASTM D524 0.12
resid
Ash content ASTM D482 0.002
Acid Number ASTM D664 <0.05
Copper Corrosion ASTM D130 113
Cetane Number ASTM D613 46.5
Cetane Index ASTM D976 45.6
Cetane Index ASTM D4737 45.3
It can be seen that the treat curve for Additive A provides acceptable
demerits (less than
10) at approximately 50 ppm, whereas the Comparative Additive fails to reach
acceptable
demerits at a treat rate well in excess of 100 ppm, showing the improved
efficacy of the
additive to the invention.
