Note: Descriptions are shown in the official language in which they were submitted.
_.
CA 02287660 1999-10-26
4 v
Clariant GmbH 1998DE433 Dr.KM/sch
Description
Polymer mixtures for improving the lubricity of middle distillates
The present invention relates to additives comprising hydroxyl-containing
copolymers and polar nitrogen compounds which provide middle distillates with
better lubricity, and to the corresponding additive-containing middle
distillates.
Mineral oils and mineral oil distillates used as fuel oils generally contain
0.5% by
weight or more of sulfur, which, on burning, causes the formation of sulfur
dioxide. In
order to reduce the resultant environmental pollution, the sulfur content of
fuel oils is
continually being reduced further. The EN 590 standard relating to diesel
fuels
currently prescribes a maximum sulfur content of 500 ppm in Germany. In
Scandinavia, fuel oils containing less than 200 ppm and in exceptional cases
less
than 50 ppm of sulfur are already in use. These fuel oils are generally
produced by
hydrotreating the fractions obtained from the crude oil by distillation.
However, the
desulfurization also removes other substances which provide the fuel oils with
a
natural lubricity. These substances include, inter alia, polyaromatic and
polar
compounds.
However, it has now been found that the friction- and wear-reducing properties
of
fuel oils worsen with increasing degree of desulfurization. These properties
are
frequently so poor that the fuel-lubricated materials, such as, for example,
the
distributor injection pumps of diesel engines, can be expected to exhibit
signs of
wear after only a short time. The further lowering of the 95% distillation
point to
below 370°C, in some cases to below 350°C or below 330°C,
which has in the
meantime been carried out in Scandinavia, further exacerbates this problem.
The prior art therefore describes attempts to solve this problem (so-called
lubricity
additives).
CA 02287660 1999-10-26
. .
2
EP-A-0 764 198 discloses additives which improve the lubricity of fuel oils
and which
comprise polar nitrogen compounds based on alkylamines or alkylammonium salts
containing alkyl radicals having 8 to 40 carbon atoms.
EP-A-0 743 972 discloses the use of mixtures of lubricity additives (esters of
polyhydric alcohols and carboxylic acids having 2 to 50 carbon atoms or
dicarboxylic
acids) and nitrogen-containing compounds for synergistic improvement of the
lubricity of highly desulfurized oils. The nitrogen-containing compounds
employed
are paraffin inhibitors containing amides or ammonium salts of dicarboxylic
acids
with fatty amines.
WO 98/16597 discloses the use of C,-C3o-, preferably C9-C24-alkylphenols,
their
condensation products with aldehydes, and corresponding alkoxylates as
lubricity
additives for middle distillates.
The object of the present invention was to find multifunctional additives
which result
in an improvement in lubricity in middle distillates which have been
substantially
freed from sulfur and aromatic compounds. At the same time, these additives
should
also improve the inadequate effectiveness in various oil grades of paraffin
dispersants, which retard or prevent sedimentation of the paraffin crystals
formed in
such middle distillates at low temperatures.
Surprisingly, it has been found that polymer mixtures comprising hydroxyl-
containing
copolymers and simultaneously polar nitrogen compounds are capable of
positively
affecting both the lubricity and the cold-flow properties of middle
distillates and in
particular paraffin dispersal. The mixtures have the advantage that the effect
can be
achieved using lower metering rates than is the case for the components of the
mixtures.
The invention relates to an additive for fuel oils, comprising
A) from 10 to 90% by weight of at least one copolymer of ethylene and at least
CA 02287660 1999-10-26
. .
3
one further olefinically unsaturated comonomer containing one or more
hydroxyl groups, and
B) from 90 to 10% by weight of at least one polar nitrogen-containing
compound.
The olefinically unsaturated compounds which make up the hydroxyl-containing
comonomers of component A) are preferably vinyl esters, acrylates,
methacrylates,
alkyl vinyl ethers and/or alkenes carrying hydroxyalkyl, hydroxyalkenyl,
hydroxycycloalkyl or hydrvxyaryl radicals. These radicals contain at least one
hydroxyl group, which can be in any desired position of the radical, but is
preferably
at the chain end (w-position) or in the para-position in the case of ring
systems. The
copolymers which make up component A) may, if desired, also comprise further
comonomers in addition to ethylene and olefinically unsaturated compounds
containing hydroxyl groups.
The vinyl esters are preferably those of the formula 1
CH2 = CH - OCOR' (1 )
in which R' is C,-C3°-hydroxyalkyl, preferably C,-C,2-hydroxyalkyl,
especially C2-Cs-
hydroxyalkyl, and the corresponding hydroxyoxalkyl radicals. Suitable vinyl
esters
include 2-hydroxyethyl vinyl esters, a-hydroxypropyl vinyl esters, 3-
hydroxypropyl
vinyl esters and 4-hydroxybutyl vinyl esters.
The acrylates are preferably those of the formula (2)
CHZ = CRz - CUOR3 (2)
in which R2 is hydrogen or methyl, and R3 is C,-C3°-hydroxyalkyl,
preferably C,-C,2-
hydroxyalkyl, especially CZ-C6-hydroxyalkyl, and the corresponding
hydroxyoxalkyl
radicals. Suitable acrylates include hydroxyethyl acrylate, diethylene glycol
monoacrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate,
hydroxyisopropyl
CA 02287660 1999-10-26
4
acrylate, 4-hydroxybutyl acrylate, glycerol monoacrylate and the corresponding
esters of methacrylic acid.
The alkyl vinyl ethers are preferably compounds of the formula 3
CHZ = CH - OR4 (3)
in which R4 is C,-C3°-hydroxyalkyl, preferably C~-C,2-hydroxyalkyl,
especially C2-Cs-
hydroxyalkyl and the corresponding hydroxyoxalkyl radicals. Suitable alkyl
vinyl
ethers include 2-hydroxyethyl vinyl ether, hydroxypropyl vinyl ether,
hexanediol
monovinyl ether, 4-(hydroxybutyl)vinyl ether, diethylene glycol monovinyl
ether and
cyclohexanedimethanol monovinyl ether.
The alkenes are preferably monounsaturated hydroxyhydrocarbons having 3 to
30 carbon atoms, in particular 4 to 16 carbon atoms, especially 5 to 12 carbon
atoms. Preferred hydroxy hydrocarbons are also those in which the carbon chain
is
interrupted by oxygen. Suitable alkenes include dimethylvinylcarbinol (= 2-
methyl-3-
buten-2-ol), allyloxypropanediol, 2-butene-1,4-diol, 1-buten-3-ol, 3-buten-1-
ol,
2-buten-1-ol, 1-penten-3-ol, 1-penten-4-ol, 2-methyl-3-buten-1-ol, 1-hexen-3-
ol,
5-hexen-1-of and 7-octene-1,2-diol.
The molar proportion of hydroxyl-functionalized comonomers in the copolymer
(A) is
preferably from 0.5 to 13%, in particular from 3 to 10%. The OH number of the
copolymers is preferably between 1 and 800, in particular between 5 and 200,
especially between 10 and 100 mg of KOH/g of polymer.
The melt viscosities of the hydroxyl-functionalized copolymers (A) at
140°C are
preferably below 10,000 mPas, in particular between 10 and 1000 mPas,
especially
between 15 and 500 mPas. Preference is given to copolymers having mean
molecular weights (number average) of 500-100,000 units, in particular from
1000 to
50,000 units, especially from 1000 to 10,000 units. The melt viscosities and
CA 02287660 1999-10-26
molecular weights must in all cases be such that the copolymers are oil-
soluble.
Besides ethylene, component (A) of the novel additives comprises at least one
comonomer containing hydroxyl groups. It may also contain further, for example
5 one, two or three further, olefinically unsaturated comonomers. Examples of
such
olefinically unsaturated comonomers are vinyl esters, acrylic acid,
methacrylic acid,
acrylic esters, methacrylic esters, vinyl ethers and olefins. Particularly
preferred vinyl
esters are vinyl acetate, vinyl hexanoate, vinyl octanoate, vinyl 2-
ethylhexanoate,
vinyl laurate, vinyl propionate and vinyl esters of neocarboxylic acids having
8, 9, 10,
11 or 12 carbon atoms. Particularly preferred acrylic and methacrylic esters
are
those with alcohols having 1 to 20 carbon atoms, in particular with methanol,
ethanol, propanol, n-butanol, isobutanol and tert-butanol. Particularly
preferred
olefins are those having 3 to 10 carbon atoms, especially propene, 1-butene,
isobutylene, diisobutylene, 4-methyl-1-pentene, heptene, octene, norbornene
and
hexene. Particular preference is given to terpolymers of ethylene, a hydroxyl-
functionalized comonomer and either vinyl acetate or a vinyl ester of a
neocarboxylic
acid having 8 to 12 carbon atoms. In a preferred embodiment of the invention,
the
hydroxyl-containing copolymers (A) comprise up to 16 mol%, in particular from
3 to
14 mol%, of these vinyl or (meth)acrylic esters.
The novel additives comprise at least one polar nitrogen compound (B). In
preferred
embodiments of the invention, these polar nitrogen compounds are those formed
by
the reaction of a nitrogen compound of the formula NR6R'R°, in which
R6, R' and R8
may be identical or different, and at least one of these groups is C8-C36-
alkyl, Cs-C3s-
cycloalkyl, Ce-C~-alkenyl, in particular C,2-C24-alkyl, C,2-C24-alkenyl or
cyclohexyl,
and the other groups are hydrogen, C,-C36-alkyl, C2-C36-alkenyl, cyclohexyl,
or a
group of the formula -(A-O)X E or -(CHZ)~ NYZ, in which A is an ethylene or
propylene group, X is a number from 1 to 50, E is H, C,-C3°-alkyl, CS-
C,2-cycloalkyl
or Cs-C3°-aryl, and n is 2, 3 or 4, and Y and Z, independently of one
another, are H,
C,-C3°-alkyl or -(A-O)X E, with a compound containing an acyl group.
The term acyl
group here is taken to mean a functional group of the following formula:
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6
Preferred carbonyl-containing compounds are carboxylic acids and their
anhydrides
and esters. Preferred polar nitrogen-containing compounds are listed below.
B1) Products of the reaction of alkenylspirobislactones of the formula 4
R5 Rs
O~O~O
in which each RS is C8-CZao-alkenyl, with amines of the formula NRsR'R8.
Suitable
reaction products are listed in EP-A-0 413 279. Depending on the reaction
conditions, the reaction of compounds of the formula (4) with the amines gives
amides or amide-ammonium salts.
B2) Amides or ammonium salts of aminoalkylenepolycarboxylic acids with
secondary amines of the formula 5 or 6
Rs Rs
\ N-CO-CHz CHz-CO-N/
R~~ ~ ~ ~ R~
Rs N_R~o-N Rg
7 i N-CO-CHz \CHz-CO-N ~
R R~
Rg
CHz-CO-N ~ R~
Rs (s)
N CHz-CO_N \ R~
6
CHz-CO-N ~ R
R'
in which
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7
R'° is a straight-chain or branched alkylene radical having 2 to 6
carbon atoms or
the radical of the formula 7
-C H 2-C H 2-N -C H 2-C H 2-
/Rs
CHZ-COONS
R~
in which R6 and R' are in particular alkyl radicals having 10 to 30 carbon
atoms,
preferably 14 to 24 carbon atoms where the amide structures may also be partly
or
fully in the form of the ammonium salt structure of the formula 8
Rg\
~NH2~0 -
(8)
R /
The amides or amide-ammonium salts or ammonium salts, for example of
nitrotriacetic acid, of ethylenediaminetetraacetic acid or of propylene-1,2-
diaminotetraacetic acid, are obtained by reacting acids with from 0.5 to 1.5
mol of
amine, preferably from 0.8 to 1.2 mol of amine, per carboxyl group. The
reaction
temperatures are from about 80 to 200°C, where, in order to prepare the
amides, the
resultant water of reaction is removed continuously. However, the reaction
need not
be continued completely to the amide, but instead from 0 to 100 mol% of the
amine
employed can be in the form of the ammonium salt. Under analogous conditions,
the
compounds mentioned under B1) can also be prepared.
Suitable amines of the formula 9
Re
\NH (9)
R~
CA 02287660 1999-10-26
are in particular dialkylamines in which R6 and R' are a straight-chain alkyl
radical
having 10 to 30 carbon atoms, preferably 14 to 24 carbon atoms. Specific
mention
may be made of dioleylamine, dipalmitylamine, dicoconut fatty amine and
dibehenylamine, and preferably ditallow fatty amine.
B3) Quaternary ammonium salts of the formula 10
~NR6R'R8R"Xe (10)
in which Rs, R' and R8 are as defined above, and R" is C,-C3o-alkyl,
preferably C,-
C2z-alkyl, C2-C3o-alkenyl, preferably C2-C22-alkenyl, benzyl or a radical of
the formula
-(CH2-CH2-O)~-R'2, where R'2 is hydrogen or a fatty acid radical of the
formula C(O)-
R'3, where R'3 is C6-C4o-alkenyl, n is a number from 1 to 30, and X is
halogen,
preferably chlorine, or a methylsulfate.
Examples of such quaternary ammonium salts which may be mentioned are the
following: dihexadecyldimethylammonium chloride, distearyldimethylammonium -
chloride, quaternization products of esters of di- and triethanolamine with
long-chain
fatty acids (lauric acid, myristic acid, palmitic acid, stearic acid, behenic
acid, oleic
acid and fatty acid mixtures, such as coconut fatty acid, tallow fatty acid,
hydrogenated tallow fatty acid, tallow oil fatty acid), such as
N-methyltriethanolammonium distearyl ester chloride, N-
methyltriethanolammonium
distearyl ester methylsulfate, N,N-dimethyldiethanolammonium distearyl ester
chloride, N-methyltriethanolammonium dioleyl ester chloride,
N-methyltriethanolammonium trilauryl ester methylsulfate,
N-methyltriethanolammonium tristearyl ester methylsulfate and mixtures
thereof.
B4) Compounds of the formula 11
R~4
CONRgR~
(11)
Rye
R~s
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9
in which R'4 is CONR6R' or C02 +HZNR6R', R'S and R'6 are H, CONR"Z, C02R" or
OCOR", -OR", -R" or -NCOR" and
R" is alkyl, alkoxyalkyl or polyalkoxyalkyl and has at least 10 carbon atoms.
Preferred carboxylic acids or acid derivatives are phthalic acid (anhydride),
trimellitic
acid, pyromellitic acid (dianhydride), isophthalic acid, terephthalic acid,
cyclohexanedicarboxylic acid (anhydride), malefic acid (anhydride) and
alkenylsuccinic acid (anhydride). The formulation (anhydride) means that the
anhydrides of said acids are also preferred acid derivatives.
If the compounds (11) are amides or amine salts, they are preferably derived
from a
secondary amine containing a hydrogen- and carbon-containing group having at
least 10 carbon atoms.
R" preferably contains 10 to 30, in particular 10 to 22, for example 14 to 20,
carbon
atoms and is preferably straight-chain or branched at the 1- or 2-position.
The other
hydrogen- and carbon-containing groups may be shorter, for example may contain
less than 6 carbon atoms, or, if desired, can have at least 10 carbon atoms.
Suitable
alkyl groups include methyl, ethyl, propyl, hexyl, decyl, dodecyl, tetradecyl,
hexadecyl, eicosyl and docosyl, and mixtures thereof, such as coconut fatty
alkyl,
tallow fatty alkyl and behenyl.
Also suitable are polymers containing at least one amide or ammonium group
bonded directly to the polymer skeleton, where the amide or ammonium group
carries at least one alkyl group of at least 8 carbon atoms on the nitrogen
atom.
Such polymers can be prepared in various ways. One method is to use a polymer
containing a plurality of carboxyl or carboxylic anhydride groups and to react
this
polymer with an amine of the formula NHRsR' in order to obtain the desired
polymer.
Suitable polymers here are in general copolymers comprising unsaturated
esters,
such as C,-C4o-alkyl (meth)acrylates, di-C,-C4o-alkyl fumarates, C,-C4o-alkyl
vinyl
CA 02287660 1999-10-26
ethers, C,-C4o-alkyl vinyl esters or C2-C4o-olefins (linear, branched or
aromatic) with
unsaturated carboxylic acids or reactive derivatives thereof, such as, for
example,
carboxylic anhydrides (acrylic acid, methacrylic acid, malefic acid, fumaric
acid,
tetrahydrophthalic acid, citraconic acid, preferably malefic anhydride).
5
Carboxylic acids are preferably reacted with from 0.1 to 1.5 mol, in
particular from
0.5 to 1.2 mol, of amine per acid group, carboxylic anhydrides are preferably
reacted
with from 0.1 to 2.5 mol, in particular from 0.5 to 2.2 mol, of amine per acid
anhydride group, giving, depending on the reaction conditions, amides,
ammonium
10 salts, amide-ammonium salts or imides. Thus, copolymers containing
unsaturated
carboxylic anhydrides give, on reaction with a secondary amine, 50% of amide
and
50% of amine salts owing to the reaction with the anhydride group. Heating
allows
water to be eliminated with formation of the diamide.
Particularly suitable examples of amide group-containing polymers for the
novel use
are the following:
B5) copolymers (a) of a dialkyl fumarate, maleate, citraconate or itaconate
with
malefic anhydride, or (b) of vinyl esters, for example vinyl acetate or vinyl
stearate
with malefic anhydride, or (c) of a dialkyl fumarate, maleate, citraconate or
itaconate
with malefic anhydride and vinyl acetate.
Particularly suitable examples of these polymers are copolymers of didodecyl
fumarate, vinyl acetate and malefic anhydride; ditetradecyl fumarate, vinyl
acetate
and malefic anhydride; dihexadecyl fumarate, vinyl acetate and malefic
anhydride; or
the corresponding copolymers in which the fumarate has been replaced by the
itaconate.
In the abovementioned examples of suitable palymers, the desired amide is
obtained by reacting the polymer containing anhydride groups with a secondary
amine of the formula HNR6R' (if desired in addition with an alcohol if an
ester-amide
is formed). If polymers containing an anhydride group are reacted, the
resultant
CA 02287660 1999-10-26
11
amino groups will be ammonium salts and amides. Such polymers can be used with
the proviso that they contain at least two amide groups.
It is essential that the polymer containing at least two amide groups contains
at least
one alkyl group having at least 10 carbon atoms. This long-chain group, which
may
be a straight-chain or branched alkyl group, can be bonded to the amide group
via
the nitrogen atom.
The amines suitable for this purpose can be represented by the formula R6R'NH
and
the polyamines by R6NH[R'9NH]XR', where R'9 is a divalent hydrocarbon group,
preferably an alkylene or hydrocarbon-substituted alkylene group, and x is an
integer, preferably between 1 and 30. One of the two or the two radicals R6
and R'
preferably contain at least 10 carbon atoms, for example from 10 to 20 carbon
atoms, for example dodecyl, tetradecyl, hexadecyl or octadecyl.
Examples of suitable secondary amines are dioctylamine and those containing
alkyl
groups having at least 10 carbon atoms, for example didecylamine,
didodecylamine,
dicoconut amine (i.e. mixed C,2-C,4-amines), dioctadecylamine,
hexadecyloctadecylamine, di(hydrogenated tallow)amine (approximately 4% by
weight of n-C,4-alkyl, 30% by weight of n-C,°-alkyl, 60% by weight of n-
C,8-alkyl, the
remainder is unsaturated).
Examples of suitable polyamines are N-octadecylpropanediamine,
N,N'-dioctadecylpropanediamine, N-tetradecylbutanediamine and
N,N,-dihexadecylhexanediamine. N-(Coconut)propylenediamine (C,2/C,4
alkylpropylenediamine), N-(tallow)propylenediamine (C,s/C,8-alkyl
propylenediamine).
The amide-containing polymers usually have an average molecular weight (weight
average) of from 1000 to 500,000, for example from 2000 to 100,000.
CA 02287660 1999-10-26
12
B6) Copolymers of styrene, its derivatives or aliphatic olefins having 2 to
40 carbon atoms, preferably 6 to 20 carbon atoms, and olefinically unsaturated
carboxylic acids or carboxylic anhydrides which have been reacted with amines
of
the formula NHR6R'. The reaction can be carried out before or after the
polymerization.
In detail, the structural units of the copolymers are derived from, for
example, malefic
acid, fumaric acid, tetrahydrophthalic acid, citraconic acid, preferably
malefic
anhydride. They can be employed either in the form of their homopolymers or of
the
copolymers. Suitable comonomers are the following: styrene and alkylstyrenes,
straight-chain and branched olefins having 2 to 40 carbon atoms, and mixtures
thereof with one another. Examples which may be mentioned are styrene,
a-methylstyrene, dimethylstyrene, a-ethylstyrene, diethylstyrene, i-
propylstyrene,
tert-butylstyrene, ethylene, propylene, n-butylene, di-i-butylene, decene,
dodecene,
tetradecene, hexadecene and octadecene. Preference is given to styrene and
isobutene, particularly preferably styrene.
Examples of polymers which may be mentioned individually are the following:
polymaleic acid, a molar copolymer built up alternatively from styrene/maleic
acid,
copolymers built up randomly from styrene, malefic acid in a ratio of 10:90,
and an
alternating copolymer of malefic acid and i-butene. The molar masses of the
polymers are generally from 500 g/mol to 20,000 glmol, preferably from 700 to
2000 g/mol.
The reaction of the polymers or copolymers with the amines is carried out at
temperatures of from 50 to 200°C for a period of from 0.3 to 30 hours.
The amine is
used in amounts of approximately one mole per mole of copolymerized
dicarboxylic
anhydride, i.e, from about 0.9 to 1.1 mol/mol. The use of larger or smaller
amounts is
possible, but brings no advantage. If larger amounts than one mole are used,
certain
amounts of ammonium salts are obtained since the formation of a second amide
group requires higher temperatures, longer residence times and removal of
water. If
CA 02287660 1999-10-26
13
smaller amounts than one mole are used, incomplete conversion to the monoamide
takes place, and a correspondingly reduced effect is obtained.
Instead of the subsequent reaction of the carboxyl groups in the form of the
dicarboxylic anhydride with amines to give the corresponding amides, it may
sometimes be advantageous to prepare the monoamides of the monomers and then
to copolymerize them directly during the polymerization. However, this is
usually
much more complex technically since the amines can add onto the double bond of
the monomeric mono- and dicarboxylic acid, and copolymerization is then no
longer
possible.
B7) Copolymers consisting of from 10 to 95 mol% of one or more alkyl acrylates
or alkyl methacrylates having C,-C26-alkyl chains and from 5 to 90 mol% of one
of
more ethylenically unsaturated dicarboxylic acids or anhydrides thereof, where
the
copolymer has been reacted substantially with one or more primary or secondary
amines to give the monoamide or amide/ammonium salt of the dicarboxylic acid.
The copolymers consist of from 10 to 95 mol%, preferably from 40 to 95 mol%,
particularly preferably from 60 to 90 mol%, of alkyl (meth)acrylates and from
5 to
90 mol%, preferably from 5 to 60 mol%, particularly preferably from 10 to 40
mol%,
of olefinically unsaturated dicarboxylic acid derivatives.
The alkyl groups of the alkyl (meth)acrylates contain from 1 to 26, preferably
from 4
to 22, particularly preferably from 8 to 18, carbon atoms. They are preferably
straight-chain and unbranched. However, it is also possible for them to
contain up to
20% by weight of cyclic and/or branched components.
Examples of particularly preferred alkyl (meth)acrylates are n-octyl
(meth)acrylate,
n-decyl (meth)acrylate, n-dodecyl (meth)acrylate, n-tetradecyl (meth)acrylate,
n-hexadecyl (meth)acrylate and n-octadecyl (meth)acrylate, and mixtures
thereof.
CA 02287660 1999-10-26
14
Examples of ethylenically unsaturated dicarboxylic acids are malefic acid,
tetrahydrophthalic acid, citraconic acid and itaconic acid and anhydrides
thereof, and
fumaric acid. Preference is given to malefic anhydride.
Suitable amines are compounds of the formula NHR6R'.
In general, it is advantageous to carry out the copolymerization using the
dicarboxylic acids in the form of the anhydrides, if available, for example
malefic
anhydride, itaconic anhydride, citraconic anhydride and tetrahydrophthalic
anhydride, since the anhydrides generally copolymerize better with the
(meth)acrylates. The anhydride groups of the copolymers can then be reacted
directly with the amines.
The reaction of the polymers with the amines is carried out at temperatures of
from
50 to 200°C for a period of from 0.3 to 30 hours. The amine is used in
amounts of
from approximately 1 to 2 mol per mole of copolymerized dicarboxylic
anhydride, i.e.
from about 0.9 to 2.1 mol/mol. The use of larger or smaller amounts is
possible, but
there is no advantage. If larger amounts than two mole are used, free amine is
present. If smaller amounts that one mole are used, incomplete conversion to
the
monoamide takes place, and a correspondingly reduced action is obtained.
In some cases, it may be advantageous for the amide/ammonium salt structure to
be
built up from two different amines. Thus, for example, a copolymer of lauryl
acrylate
and malefic anhydride can first be reacted with a secondary amine, such as
hydrogenated ditallow fatty amine, to give the amide, and the free carboxyl
group
originating from the anhydride can then be neutralized using another amine,
for
example 2-ethylhexylamine, to give the ammonium salt. The reverse procedure is
equally feasible: first reaction with ethylhexylamine to give the monoamide,
then with
ditallow fatty amine to give the ammonium salt. It is preferred to use at
least one
amine containing at least one straight-chain, unbranched alkyl group having
more
than 16 carbon atoms. It is unimportant whether this amine is involved in the
build-
CA 02287660 1999-10-26
up of the amide structure or is in the form of the ammonium salt of the
dicarboxylic
acid.
Instead of subsequently reacting the carboxyl groups or dicarboxylic anhydride
with
5 amines to give the corresponding amides or amide/ammonium salts, it may
sometimes be advantageous to prepare the monoamides or amide/ammonium salts
of the monomers and then to copolymerize thern directly during the
polymerization.
Usually, however, this is much more technically complex, since the amines can
add
onto the double bond of the monomeric dicarboxylic acid, and copolymerization
is
10 then no longer possible.
B8) Terpolymers based on a,~i-unsaturated dicarboxylic anhydrides, a,~3-
unsaturated compounds and polyoxyalkylene ethers of lower, unsaturated
alcohols,
which comprise 20-80 mol%, preferably 40-60 mol%, of divalent structural units
of
15 the formula 12 and/or 14 and, if desired, 13, where the structural units 13
originate
from unreacted anhydride radicals,
R22 (R23)b
(Rzs)e C C
(12)
O C C O
R24 Rzs
(R23)b
(Rzs)e C C
(13)
O C C p
- CA 02287660 1999-10-26
16
R~ (Rz3)b
(Rz3)e C C
(14)
O C C _-__: p
N/
Rg
where
R22 and R23, independently of one another, are hydrogen or methyl,
a and b are zero or one and a + b equals one,
R24 and R25 are identical or different and are the -NHR6, N(R6)2 and/or -OR2'
groups,
and R2' is a cation of the formula H2N(Rs)2~ or H3NR8~,
19-80 mol%, preferably 39-60 mol%, of divalent structural units of the formula
15
Rze
CHz C-- (15)
Rzs
in which
RZ° is hydrogen or C,-C4-alkyl and
R29 is Cs-C6°-alkyl or C6-C,8-aryl, and
1-30 mol%, preferably 1-20 mol%, of divalent structural units of the formula
16
R3o
CHz C (16)
R33 - p _ (CHz-CH-O)m - R3z
R31
CA 02287660 1999-10-26
17
in which
R3° is hydrogen or methyl,
R3' is hydrogen or C,-C4 alkyl,
R33 is C,-C4 alkylene,
m is a number from 1 to 100,
R32 is C,-C24-alkyl, C5-C2°-cycloalkyl, C6 C,8-aryl or -C(O)-
R~°, where
R~ is C,-C4°-alkyl, C5-C,°-cycloalkyl or Cs-C,8-aryl.
The abovementioned alkyl, cycloalkyl and aryl radicals may, if desired, be
substituted. Suitable substituents of the alkyl and aryl radicals are, for
example,
(C,-Cs)-alkyl, halogens, such as fluorine, chlorine, bromine and iodine,
preferably
chlorine, and (C,-C6)-alkoxy.
Alkyl here represents a straight-chain or branched hydrocarbon radical.
Specific
mention may be made of the following: n-butyl, tert-butyl, n-hexyl, n-octyl,
decyl,
dodecyl, tetradecyl, hexadecyl, octadecyl, dodecenyl, tetrapropenyl,
tetradecenyl,
pentapropenyl, hexadecenyl, octadecenyl and eicosanyl, or mixtures, such as
coconut-alkyl, tallow fatty alkyl and behenyl.
Cycloalkyl here represents a cyclic aliphatic radical having 5-20 carbon
atoms.
Preferred cycloalkyl radicals are cyclopentyl and cyclohexyl.
Aryl here represents a substituted or unsubstituted aromatic ring system
having 6 to
18 carbon atoms.
The terpolymers consist of the divalent structural units of the formulae 12
and/or 14
and 15 and 16 and, if desired, 13. They merely still contain the end groups
formed in
a known manner during the polymerization by initiation, inhibition and chain
termination.
CA 02287660 1999-10-26
18
In detail, the structural units of the formulae 12 to 14 are derived from a,~i-
unsaturated dicarboxylic anhydrides of the formulae 17 and 18
R22 R23
C C (17)
O ~ ~ O
O
R~
H2C C C R23
(18)
O ~ ~ O
O
such as malefic anhydride, itaconic anhydride, citraconic anhydride,
preferably
malefic anhydride.
The structural units of the formula 15 are derived from the a,~3-unsaturated
compounds of the formula 19
R28
H2C C
2 5 R2a
Examples which may be mentioned are the following a,~i-unsaturated olefins:
styrene, a-methylstyrene, dimethylstyrene, a-ethylstyrene, diethylstyrene,
i-propylstyrene, tert-butylstyrene, diisobutylene and a-olefins, such as
decene,
dodecene, tetradecene, pentadecene, hexadecene, octadecene, C2o-a-olefin, C24-
a-
olefin, C3o-a-olefin, tripropenyl, tetrapropenyl, pentapropenyl and mixtures
thereof.
CA 02287660 1999-10-26
19
Preference is given to a-olefins having 10 to 24 carbon atoms and styrene,
particularly preferably a-olefins having 12 to 20 carbon atoms.
The structural units of the formula 16 are derived from polyoxyalkylene ethers
of
lower, unsaturated alcohols of the formula 20
R3o
(20)
H2C C
R33 - p - (CHZ - ~ H - 0)m - R32
R3~
The monomers of the formula 20 are products of the etherification (R32 = -
C(O)R~°)
or esterification (R3z = -C(O)RD) of polyoxyalkylene ethers (R32 = H).
The polyoxyalkylene ethers (R32 = H) can be prepared by known processes by the
adduction of a-olefin oxides, such as ethylene oxide, propylene oxide and/or
butylene oxide, onto polymerizable lower, unsaturated alcohols of the formula
21
Rao
(21)
H2C C R33 -- pH
Polymerizable lower unsaturated alcohols of this type are, for example, allyl
alcohol,
methallyl alcohol, butenols, such as 3-buten-1-of and 1-buten-3-of or
methylbutenols,
such as 2-methyl-3-buten-1-ol, 2-methyl-3-buten-2-of and 3-methyl-3-buten-1-
ol.
Preference is given to products of the adduction of ethylene oxide and/or
propylene
oxide onto allyl alcohol.
Subsequent etherification of these polyoxyalkylene ethers to give compounds of
the
formula 20 in which R32 = C,-C24-alkyl, cycloalkyl or aryl is carried out by
processes
known per se. Suitable processes are disclosed, for example, in J. March,
Advanced
CA 02287660 1999-10-26
Organic Chemistry, 2nd Edition, pp. 357 ff (1977). These products of the
etherification of polyoxyalkylene ethers can also be prepared by adducting a-
olefin
oxides, preferably ethylene oxide, propylene oxide and/or butylene oxide, onto
alcohols of the formula 22
5
R32 - OH (22)
in which R32 is C,-Cz4-alkyl, C5-CZO-cycloalkyl or C6-C,8-aryl, by known
methods and
reacting the product with polymerizable lower unsaturated halides of the
formula 23
R~
HZC C Z -_ W
(23)
where W is a halogen atom. Preferred halides are the chlorides and bromides.
Suitable preparation processes are given, for example, in J. March, Advanced
Organic Chemistry, 2nd Edition, pp. 357 ff (1977).
The esterification of the polyoxyalkylene ethers (R32 = -C(O)-R~') is carried
out by
reaction with customary esterification agents, such as carboxylic acids,
carboxylic
acid halides, carboxylic anhydrides or carboxylic esters with C,-C4 alcohols.
Preference is given to the halides and anhydrides of C,-C4o-alkyl-, C5-C,o-
cycloalkyl-
or Cg-C,e-arylcarboxylic acids. The esterification is generally carried out at
temperatures of from 0 to 200°C, preferably from 10 to 100°C.
In the monomers of the formula 20, the index m denotes the degree of
alkoxylation,
i.e. the number of moles of a-olefin adducted per mole of the formula 20 or
21.
Examples of primary amines which are suitable for the preparation of the
terpolymers are the following:
n-hexylamine, n-octylamine, n-tetradecylamine, n-hexadecylamine, n-
stearylamine
CA 02287660 1999-10-26
21
or alternatively N,N-dimethylaminopropylenediamine, cyclohexylamine,
dehydroabietylamine and mixtures thereof.
Examples of secondary amines which are suitable for the preparation of the
terpolymers are the following: didecylamine, ditetradecylamine,
distearylamine,
dicoconut fatty amine, ditallow fatty amine and mixtures thereof.
The terpolymers have K values (measured by the Ubbelohde method in 5% strength
by weight solution in toluene at 25°C) of from 8 to 100, preferably 8
to 50,
corresponding to mean molecular weights (117r w) of between about 500 and
1,000,000. Suitable examples are given in EP 506 055.
B9) Products of the reaction of alkanolamines and/or polyether amines with
polymers containing dicarboxylic anhydride groups, which contain 20-80 mol%,
preferably 40-60 mol%, of divalent structural units of the formulae 25 and 27
and, if
desired, 26
RTT (RT3)b
Ts (25)
(R ). C C
O C C p
R3~ R3a
RTT (RT3)b
T3 ( (26)
(R ), C C
p C C p
~ o
' CA 02287660 1999-10-26
22
R22 (R23)b
23 ~ 27
(R ), C C ( )
O C C p
' N'
R3s
where
R22 and R23, independently of one another, are hydrogen or methyl,
a and b are zero or 1 and a + b equals 1,
R3' is -OH, -O-[C,-C3o alkyl], -NRgR' or -OeN~R6R'H2
R38 is R3' or NRgR3a
R3a is -(A-O)X E (28)
where A is an ethylene or propylene,
x is from 1 to 50
and E is H, C,-C3o-alkyl, CS-C,2-cycloalkyl or C6-C3°-aryl, and
80 - 20 mol%, preferably 60-40 mol%, of divalent structural units of the
formula 15.
In detail, the structural units of the formulae 25, 26 and 27 are derived from
a,[i-unsaturated dicarboxylic anhydrides of the formulae 17 and/or 18.
The structural units of the formula 15 are derived from a,[3-unsaturated
olefins of the
formula 19. The abovementioned alkyl, cycloalkyl and aryl radicals have the
same
meanings as under B8).
The radicals R3' and R38 in the formula 25 or R39 in the formula 27 are
derived from
polyether amines or alkanolamines of the formula H2N-(A-O)X E, amines of the
formula NRgR'R° and, if appropriate, from alcohols having 1 to 30
carbon atoms.
CA 02287660 1999-10-26
23
In order to derivatize the structural units of the formulae 17 and 18,
mixtures of at
least 50% by weight of alkylamines of the formula HNRsR'R8 and at most 50% by
weight of polyether amines and/or alkanolamines of the formula H2N-(A-O)X E
are
preferably used.
The polyether amines employed can be prepared, for example, by reductive
amination of polyglycols. Furthermore, polyether amines containing a primary
amino
group are prepared by the addition reaction of polyglycols onto acrylonitrile
followed
by catalytic hydrogenation. In addition, polyether amines can be prepared by
reacting polyethers with phosgene or thionyl chloride followed by amination to
give
the polyether amine. The polyether amines employed in accordance with the
invention are commercially available (for example) under the name ~Jeffamine
(Texaco). Their molecular weight is up to 2000 g/mol, and the ethylene
oxide/propylene oxide ratio is from 1:10 to 6:1.
Another way of derivatizing the structural units of the formulae 17 and 18
comprises
using an alkanolamine instead of the polyether amines and subsequently
subjecting
it to alkoxylation.
From 0.01 to 2 mol, preferably from 0.01 to 1 mol, of alkanolamine are
employed per
mole of anhydride. The reaction temperature is between 50 and 100°C
(amide
formation). In the case of primary amines, the reaction is carried out at
temperatures
above 100°C (imide formation).
The alkoxylation is usually carried out at temperatures between 70 and
170°C with
catalysis by bases, such as NaOH or NaOCH3, by introducing gas-form alkylene
oxides, such as ethylene oxide (EO) and/or prapylene oxide (PO). From 1 to
500 mol, preferably from 1 to 100 mol, of alkylene oxide are usually added per
mole
of hydroxyl groups.
CA 02287660 1999-10-26
24
Examples of suitable alkanolamines which may be added are the following:
monoethanolamine, diethanolamine, N-methylethanolamine, 3-aminopropanol,
isopropanol, diglycolamine, 2-amino-2-methylpropanol and mixtures thereof.
Examples of primary amines which may be mentioned are the following:
n-hexylamine, n-octylamine, n-tetradecylamine, n-hexadecylamine, n-
stearylamine
or even N,N-dimethylaminopropylenediamine, cyclohexylamine,
dehydroabietylamine and mixtures thereof.
Examples of secondary amines which may be mentioned are the following:
didecylamine, ditetradecylamine, distearylamine, dicoconut fatty amine,
ditallow fatty
amine and mixtures thereof.
Examples of alcohols which may be mentioned are the following:
methanol, ethanol, propanol, isopropanol, n-, sec- and tert-butanol, octanol,
tetradecanol, hexadecanol, octadecanol, tallow fatty alcohol, behenyl alcohol
and
mixtures thereof. Suitable examples are listed in EP-A-688 796.
B10) Copolymers and terpolymers of N-C6-C24 alkylmaleimide with C,-
C3°-vinyl
esters, vinyl ethers and/or olefins having 1 to 30 carbon atoms, such as, for
example, styrene or a-olefins. These are accessible firstly by reacting a
polymer
containing anhydride groups with amines of the formula H2NRg or by imidation
of the
dicarboxylic acid followed by copolymerization. The preferred dicarboxylic
acid here
is malefic acid or malefic anhydride. Preference is given to copolymers
comprising
from 10 to 90% by weight of CB-C24-a-olefins and from 90 to 10% by weight of
N-Ce-C~-alkylmaleimide.
The copolymerization of the comonomers to give copolymers which are components
of the additives according to the invention is carried out by known processes
(cf. in
this respect, for example, Ullmanns Encyclopfidie der Technischen Chemie
(Ullmann's Encyclopedia of Industrial Chemistry], 4th Edition, Vol. 19, pages
169 to
CA 02287660 1999-10-26
178). Suitable processes are polymerization in solution, in suspension or in
the gas
phase and high-pressure bulk polymerization.
Component A is preferably prepared using high-pressure bulk polymerization,
which
5 is carried out at pressures of from 50 to 400 MPa, preferably from 100 to
300 MPa,
and at temperatures of from 50 to 350°C, preferably from 100 to
300°C. The reaction
of the comonomers is started by initiators which form free radicals (free-
radical chain
initiators). This class of substances includes, for example, oxygen,
hydroperoxides,
peroxides and azo compounds, such as cumene hydroperoxide, t-butyl
10 hydroperoxide, dilauroyl peroxide, dibenzoyl peroxide, bis(2-ethylhexyl)
peroxydicarbonate, di-tert-butyl peroxide, t-butyl permaleate, t-butyl
perbenzoate,
dicumyl peroxide, t-butyl cumyl peroxide, di(t-butyl) peroxide, 2,2'-azobis(2-
methylpropanonitrile) and 2,2'-azobis(2-methylbutyronitrile). The initiators
are
employed individually or as a mixture of two or more substances in amounts of
from
15 0.01 to 20% by weight, preferably from 0.05 to 10% by weight, based on the
comonomer mixture.
The desired melt viscosity of the copolymers is set for a given composition of
the
comonomer mixture by varying the reaction parameters pressure and temperature
20 and if desired by adding moderators. Moderators which have proven
successful are
hydrogen, saturated and unsaturated hydrocarbons, for example propane,
aldehydes, for example propionaldehyde, n-butyraldehyde and isobutyraldehyde,
ketones, for example acetone, methyl ethyl ketone, methyl isobutyl ketone and
cyclohexanone, and alcohols, for example butanol. Depending on the desired
25 viscosity, the moderators are used in amounts of up to 20% by weight,
preferably
from 0.05 to 10% by weight, based on the comonomer mixture.
High-pressure bulk polymerization is carried out batchwise or continuously in
known
high-pressure reactors, for example autoclaves or tubular reactors. Tubular
reactors
have proven particularly successful. Solvents, such as aliphatic hydrocarbons
or
hydrocarbon mixtures, benzene or toluene, can be present in the reaction
mixture,
CA 02287660 1999-10-26
26
although the solvent-free procedure has proven particularly successful. In a
preferred way of carrying out the polymerization, the mixture of the
comonomers, the
initiator and, if used, the moderator is fed to a tubular reactor via the
reactor inlet
and via one or more side branches; the comonamer streams can have different
compositions (EP-B-0 271 738).
Suitable copolymers for improving the lubricity of oils according to the
invention are
likewise those containing structural units derived from ethylene and vinyl
alcohol.
Copolymers of this type can be prepared by partially or fully hydrolyzing a
copolymer
containing structural units derived from ethylene and vinyl esters, for
example vinyl
acetate. These copolymers are used as a mixture with component B).
The lubricity of oils can furthermore be improved in the manner according to
the
invention by admixing them as component A with ethylene copolymers containing
alkoxylated acid groups. Examples of ethylene copolymers which are suitable
for
this purpose are those containing acrylic acid, methacrylic acid, itaconic
acid,
fumaric acid, malefic acid or malefic anhydride. In order to prepare an
additive which
improves the lubricity of oils, these copolymers containing acid groups are
alkoxylated on the acid groups using C,- to C,°-alkylene oxides.
Preferred alkylene
oxides are ethylene oxide, propylene oxide and butylene oxide. The
alkoxylation is
preferably carried out using from 0.5 to 10 mol, in particular from 1 to 5
mol,
especially from 1 to 2 mol, of alkylene oxide per mole of acid group. These
copolymers are also used as a mixture with component B).
The additives according to the invention are added to mineral oils or mineral
oil
distillates in the form of solutions or dispersions comprising from 10 to 90%
by
weight, preferably from 20 to 80% by weight, of the additives. Components A)
and
B) can be added together or separately to the oils which are to be treated
with
additives. Suitable solvents or dispersion media are aliphatic and/or aromatic
hydrocarbons or hydrocarbon mixtures, for example gasoline fractions,
kerosene,
decane, pentadecane, toluene, xylene, ethylbenzene or commercial solvent
CA 02287660 1999-10-26
27
mixtures, such as solvent naphtha, ~Shellsol AB, ~Solvesso 150, ~Solvesso 200,
~Exxsol-, ~ISOPAR and Shellsol D products, and also alcohols, ethers and/or
esters. Mineral oils and mineral oil distillates whose lubricating and/or cold-
flow
properties have been improved by the additives contain from 0.001 to 2% by
weight,
preferably from 0.005 to 0.5% by weight, of additives, based on the
distillate.
In order to prepare additive packages for specific problem solutions, the
additives
according to the invention can also be employed together with one or more oil-
soluble co-additives which, even alone, improve the cold-flow properties
and/or
lubricity of crude oils, lubricating oils or fuel oils. Examples of such co-
additives are
copolymers or terpolymers of ethylene containing vinyl esters, alkylphenol-
aldehyde
resins and comb polymers.
Thus, mixtures of the additives with copolymers comprising from 10 to 40% by
weight of vinyl acetate and from 60 to 90% by weight of ethylene have proven
highly
successful. In a further embodiment of the invention, the additives according
to the
invention are employed as a mixture with ethylene-vinyl acetate-vinyl
neononanoate
terpolymers or ethylene-vinyl acetate-vinyl neodecanoate terpolymers for
improving
the flow properties of mineral oils or mineral oil distillates. The
terpolymers of vinyl
neononanoate or vinyl neodecanoate contain, besides ethylene, from 10 to 35%
by
weight of vinyl acetate and from 1 to 25% by weight of the respective neo
compound. Also suitable are terpolymers comprising ethylene, from 10 to 35% by
weight of vinyl acetate and 1-25% by weight of 4-methyl-1-pentene or
norbornene.
The mixing ratio of the additives according to the invention with the above-
described
ethylene-vinyl acetate copolymers or the terpolymers of ethylene, vinyl
acetate and
the vinyl esters of neononanoic or neodecanoic acid is (in parts by weight)
from 20:1
to 1:20, preferably from 10:1 to 1:10.
In order to optimize the properties as flow improvers and/or lubricity
additives, the
additives according to the invention may furthermore be employed as a mixture
with
alkylphenol-formaldehyde resins. In a preferred embodiment of the invention,
these
CA 02287660 1999-10-26
28
alkylphenol-formaldehyde resins are those of the formula 29
(29)
in which R"' is linear or branched C,-Cso-alkyl ar -alkenyl, R48 is ethoxy
and/or
propoxy,
n is a number from 5 to 100, and p is a number from 0 to 50.
Finally, in a further proven variant of the invention, the additives according
to the
invention are used together with comb polymers. This is taken to mean polymers
in
which hydrocarbon radicals having at least 8 carbon atoms, in particular at
least 10
carbon atoms, are bonded to a polymer backbone. These are preferably
homopolymers whose alkyl side chains contain at least 8 and in particular at
least 10
carbon atoms. In the case of copolymers, at least 20%, preferably at least
30%, of
the monomers have side chains (cf. Comb-like Polymers - Structure and
Properties;
N.A. Platy and V.P. Shibaev, J. Polym. Sci. Macromolecular Revs. 1974, 8, 117
ffj.
Examples of suitable comb polymers are, for example, fumarate-vinyl acetate
copolymers (cf. EP 0 153 176 A1 ), copolymers of a Cg- to C24-a-olefin and an
N-Cg-
to C~-alkylmaleimide (cf. EP 0 320 766), furthermore esterified olefin-malefic
anhydride copolymers, polymers and copolymers of a-olefins and esterified
copolymers of styrene and malefic anhydride.
Comb polymers can be described, for example, by the formula 30
CA 02287660 1999-10-26
29
A H G H
- C I - I ~ m C ~ __ I ~ n (30)
D E M
in which
A is R', COOR', OCOR', R"-COOR' or OR';
D is H, CH3, A or R";
E isHorA;
G is H, R", R"-COOR', an aryl radical or a heterocyclic
radical;
M is H, COOR", OCOR", OR" or COOH;
N is H, R", COOR", OCOR, COOH or an aryl radical;
R' is a hydrocarbon chain having 8-50 carbon
atoms;
R" is a hydrocarbon chain having 1 to 10 carbon
atoms;
m is a number between 0.4 and 1.0; and
n is a number between 0 and 0.6.
The mixing ratio (in parts by weight) of the additives according to the
invention with
paraffin dispersants or comb polymers is in each case from 1:10 to 20:1,
preferably
from 1:1 to 10:1.
In order to optimize the lubricity, the additives according to the invention
can be
employed in the form of a mixture with further lubricity additives. Lubricity
additives
which have proven successful are preferably fatty alcohols, fatty acids and
dimeric
fatty acids, and esters and partial esters thereof with glycols (as described
in
DE-A-15 94 417), polyols, such as glycerol (as described in EP-A-0 680 506,
EP-A-0 739 970) or hydroxylamines (as described in EP-A-0 802 961).
The additives according to the invention are suitable for improving the
lubricating
properties of animal, vegetable or mineral oils, alcoholic fuels, such as
methanol and
CA 02287660 1999-10-26
ethanol, and mixtures of alcoholic fuels and mineral oils. They are
particularly
suitable for use in middle distillates. The term middle distillates is taken
to mean, in
particular, mineral oils boiling in the range from 120 to 450°C, and
obtained by
distillation of crude oil, for example kerosene, jet fuel, diesel and heating
oil. The
5 additives according to the invention are preferably used in middle
distillates
containing 0.5% by weight or less of sulfur, in particular less than 200 ppm
of sulfur
and in special cases less than 50 ppm of sulfur. These are generally middle
distillates which have been hydrotreated and therefore contain only small
proportions of polyaromatic and polar compounds which give them a natural
10 lubricity. The additives according to the invention are furthermore
preferably used in
middle distillates having 95% distillation points of below 370°C, in
particular below
350°C and in special cases below 330°C. At the same time, they
prevent or delay
sedimentation of precipitated paraffin crystals during storage of the oil at
low
temperatures and thus prevent or delay the formation of a paraffin-rich layer
at the
15 base of storage containers. The effectiveness of the mixtures is better
than would be
expected from the individual components.
The additives can be used alone or together with other additives, for example
with
other pour point depressants or dewaxing auxiliaries, with corrosion
inhibitors,
20 antioxidants, conductivity improvers, sludge inhibitors, dehazers and
additives for
lowering the cloud point.
The effectiveness of the additives according to the invention as lubricity
improver
and paraffin dispersants, is explained in greater detail by means of the
examples
25 below.
Examples
Characterization of the additives employed
30 The hydroxy-functional comonomers are determined by measuring the OH number
by reacting the polymer with excess acetic anhydride and then titrating the
acetic
CA 02287660 1999-10-26
31
acid formed with KOH.
The viscosity is determined in accordance with ISO 3219 (B) using a rotational
viscometer (Haake RV 20) with a plate-and-cone measurement system at
140°C.
In order to improve handling, all additives are employed in the form of 50%
solutions
in solvent naphtha or kerosene.
Table 1: Characterization of the additives A employed
Example Vinyl ester OH monomer V,4 [mPas] OH No.
No.
A1 22% vinyl acetate10% HEMA 97 43
A2 22% vin I acetate6% HEMA 77 38
A3 32% vin I versatate8% HEMA 171 38
A4 28% vinyl acetate5% DMVC 121 24
HEMA - hydroxyethyl methacrylate
VA - vinyl acetate
DMVC - dimethylvinylcarbinol
Table 2: Characterization of the additives B employed
Ex. No. Characterization
B1 Product of the reaction of a dodecenylspirobislactone
with a
mixture of primary and secondary tallow fatty
amine
B2 Product of the reaction of a terpolymer of C,4-C,s-a-olefin,
malefic anhydride and allylpolyglycol with 2
equivalents of
ditallow fatty amine
B3 Copolymer of stearylmaleimide and C,e-a-olefin
B4 Nonylphenol-formaldehyde resin
B5 Mixture of B2 and B4 in the ratio 2:1
CA 02287660 1999-10-26
32
Table 3: Characterization of the flow improvers employed
Ex. No. Comonomer(s) V,4o
(mPas]
F1 32% of vinyl acetate 140
F2 31 % of vinyl acetate + 8% of vinyl 125
neodecanoate
F3 29% of vinyl acetate + 6% of 4-methylpentene220
Table 4: Characterization of the test oils
The boiling data are determined in accordance with ASTM D-86, the CFPP value
is
determined in accordance with EN 116, and the cloud point is determined in
accordance with ISO 3015.
Test oil Test oil Test oil
1 2 3
Start of boiling198 182 172.7
[C]
20% [C] 246 202 215.9
30% [C] 260 208 231.5
90% [C] 339 286 331.7
95% [C] 355 302 350.0
Cloud point -5.2 -29 -6.6
[C]
CFPP [C] -7 -32 -9
S content [ppm]26 3 388
Density [g/cm3]0.832 0.819 0.836
Wear scar [Nm]564 609 603
Lubricity in middle distillates
The lubricity of the additives was measured at 60°C on oils treated
with additives
using a PCS Instruments high frequency reciprocating rig (HFRR). The HFRR test
is
CA 02287660 1999-10-26
33
described in D. Wei, H. Spikes, Wear, Vol. 111, No. 2, p. 217, 1986. The
results are
given as coefficient of friction and wear scar. A low coefficient of friction
and a low
wear scar value indicate a good lubricity.
Table 5: Wear scar in test oil 2
No. Amount of Amount of Wear scar Film Friction
A B
added added
1 200 ppm A1 - 559 46% 0.28
2 300 ppm A1 - 435 75% 0.20
3 400 ppm A1 - 350 80% 0.17
4 - 500 ppm B1 560 26% 0.39
5 200 ppm A1 150 ppm B1 2T3 92% 0.12
6 1000 ppm 460 48% 0.21
B2
7 200 ppm A1 150 ppm B2 373 69% 0.18
8 - 300 ppm B4 609 8% 0.34
9 - 1000 ppm 37.8 68% 0.19
B5
10 - 1000 ppm 380 69% 0.18
B3
11 100 ppm A1 250 ppm B2 343 79% 0.19
12 300 ppm A1 50 ppm B5 290 86% 0.14
13 200 ppm A1 150 ppm B4 599 11 0.32
%
14 150 ppm A1 150 ppm B5 380 65% 0.18
15 200 ppm A1 150 ppm B5 288 84% 0.14
16 200 ppm A1 150 ppm B4 340 80% 0.16
17 500 ppm A3 - 310 84% 0.16
18 200 ppm A3 150 ppm B3 242 94% 0.13
19 150 ppm A3 200 ppm B5 285 90% 0.15
20 300 ppm A4 50 ppm B1 295 88% 0.15
CA 02287660 1999-10-26
34
Table 6: Wear scar in test oil 1
No. Amount Amount Flow improverWear Film Friction
of of scar
A added B1 added
20 200 ppm - 560 16% 0.34
A1
21 300 ppm - 535 20% 0.28
A1
22 400 ppm - 238 91 0.12
A1 %
23 - 100 ppm F1 560 15% 0.35
24 - 300 ppm F1 550 17% 0.35
25 200 ppm 100 ppm F 285 87% 0.14
A1 1
26 300 ppm 100 ppm F1 203 95% 0.13
A1
27 300 ppm - 480 22~ 0.27
B2
28 200 ppm 150 ppm - 381 57~ 0.19
A1 B2
29 200 ppm 100 ppm - 313 52% 0.20
A1 B2
50 ppm
B4
30 300 ppm 100 ppm 100 ppm F 205 94% 0.12
A1 B2 1
50 ppm
B4
31 200 ppm 100 ppm 100 ppm F1 185 95% 0.12
A1 B2
50 ppm
B4
32 200 ppm 150 ppm 100 ppm f=3 347 49% 0.18
A3 B2
Table 7: Wear scar in test oil 3
No. Amount Amount of Amount Wear scar Film Friction
of B2 added of
A2 added F2 added
33 200 ppm 200 ppm 391 74 0.177
34 400 ppm - - 299 87 0.148
35 100 ppm 150 ppm 150 ppm 283 88 0.143
36 200 ppm 100 ppm 100 ppm 299 88 0.152
CA 02287660 1999-10-26
Paraffin dispersal in middle distillates
In the following experiments, a Scandinavian winter diesel fuel was used. The
middle distillate was admixed at room temperature with 100 ppm of a 50%
dispersion of a commercially available flow improver (ethylene-vinyl acetate
5 copolymer containing 32% by weight of vinyl acetate and having a melt
viscosity of
115 mPas measured at 140°C) and the amounts shown in Table 8 of the
additives
heated to 60°C, the mixture was warmed at 40°C for 15 minutes
with occasional
shaking and then cooled to room temperature. The CFPP value of the middle
distillate treated with additives in this way was determined in accordance
with
10 EN 116.
The samples treated with additives were cooled to -13°C at -
2°C/hour in 200 ml
measuring cylinders in a refrigerator and stored at this temperature for 16
hours. The
volume and appearance of both the sediment (paraffin phase) and the
supernatant
15 oil phase were then determined and assessed visually. A small amount of
sediment
and a hazy oil phase show good paraffin dispersal.
In addition, the lower 20% by volume were isolated and the cloud point
determined.
An only small difference of the cloud point of the lower phase (CPKS) from the
blank
20 value of the oil shows good paraffin dispersal.
Table 8: Dispersal action in test oil 1
Additive CFPP CPKS MCP Appearance
25 No additive (Comp.)-18 + 9.5 Clear, 17% sediment
4.3
150 ppm B2 (Comp.)-14 - 2.7 Hazy, no sediment
2.5
150 ppm B4 (Comp.)-17 + 5.8 Hazy, no sediment
p,6
150 ppm B5 (Comp.)-19 - 1.9 Hazy, no sediment
3.3
300 ppm B5 (Comp.)-14 - 5.6 Hazy, 65% sediment
0.4
30 150 ppm B5 200 - 20 - 0.6 Hazy, no sediment
ppm A1 4.6
CA 02287660 1999-10-26
36
Additive CFPP CPKS OCP Appearance
300 ppm B5 - 20 - 4.7 0.5 Hazy, no sediment
300 ppm A1
300 ppm A1 (Comp.)- 18 + 4.4 9.6 Slightly hazy, 20%
sediment
150 ppm B2 -19 - 4.4 0.8 Hazy, no sediment
150 ppm A1
150 ppm B2 -19 - 4.6 0.6 Hazy, no sediment
150 pm A4
List of trade names used
Solvent naphtha aromatic solvent mixtures having a boiling
~Shellsol AB range of from 180 to 210°C
~'Solvesso 150
~Solvesso 200 aromatic solvent mixture having a boiling range of from
230 to 287°C
~Exxsol Dearomatized solvents in various boiling ranges, for
example ~Exxsol D60: 187 to 215°C
~ISOPAR (Exxon) isoparaffinic solvent mixtures in various boiling ranges,
for example ~ISOPAR L: 190 to 210°C
~Shellsol D principally aliphatic solvent mixtures in various boiling
ranges
