Note: Descriptions are shown in the official language in which they were submitted.
2 ~ 1 8
MIDDLE DISTILLATES OF CRUDE OIL HAVING IMPROVED
COLD FLOW PROPERTIES
FIELU OF THE INVENTION
The present invention relates to middle distillates of
crude oil containing small amounts of a conventional flow impxover
on an ethylene base and copolymers of ethylenically unsaturated
carboxylic acid esters of long-chain n-alcanols with long-chain
alkylvinyl ethers, which are distinguished by improved cold flow
properties.
BACKGROUND OF THE INVENTION
Middle distillates, such as gas oil, Diesel oil or heating
oil, which are obtained from crude oil by distillation have,
depending on the source of the crude oil and depending on the type
of processing in the refinery, difPerent paraffin contents. The
proportion of long-chain n-paraffins in particu]ar determines the
cold flow properties of such distillates. During cooling, the n-
paraffins are separated in the form of platelet-iike interlaced
crystals which build up into a three-dimensiona~ network ~house of
cards structure~, where large amounts of still .Iquid distillate
are locked up and immobilized. A decrease of flowability and an
increase of the viscosity occurs parallel with the crystallization
of the n-paraffins. The supply of middle distillates to the
combustion means is made more difficult because of this. The
precipitated paraffins plug filters ahead of the~ combustion means
so that in extreme cases it is possible that the entire supply is
stopped.
It has been known for a long time that the plugging of the
filters at low temperatures can be overcome by the addition of so-
called flow improvers. By means o~ the formation of nuclei, the
: .. ,........................ :.- ,:., .':
4 1 8
additives cause the formation of many small paraffin crystals in
place of a few large ones. ~t the same time they change their
crystal modification, so that there is no formation of the above
described platelets. The paraffin crystals formed in the presence
of flow improvers are so small that they can pass through the
filters, or they build up into a filter cake which is permeable to
the still liquid portion of the middle distillatQ, so that
operation free of disruption is assured even at low temperatures.
Middle distillate cuts are appearing in increasing amounts
in the refineries, where the standard flow improvers do not have a
sufficient effect or even fail completely. This applies
particularly to so-called top draw oil, i.e. fractions with a high
final boiling point (F.B.P. > 370C). However, the boiling
properties are not the criteria. It may occur in connection with
two fractions with similar boiling point curves but dissimilar
provenance of the basic crude oil, that the standard flow improver
works well with one oil, but not with the other. In accordance
with DIN 51 428, the effectiveness of the flow ~mprover is
indirectly expressed by measuring the cold filter plugging points
(CFPP).
Ethylene copolymers, known per se, mainly copolymers of
ethylene and unsaturated esters such as described in German Patent
Disclosure DE-~-21 02 469 or European Patent Disclosure EP-A-84
148, are used as standard cold flow improvers.
However, the technology requires new flow improvers which
also show good effectiveness in connection with the above
described critical oils.
The use of polymers with linear, saturat~d side chains with
at least 18 carbon atoms for reducing the flow point of paraffin-
containing heating oil is known from German Pat~nt Disclosure DE-
A-16 45 785. These are, for example, homo- or copolymers of
2 ~
alkylesters of unsaturated mono- or dicarboxylic acids as well as
homo- or copolymers o~ various alkylvinylethers.
German Patent Disclosure DE-A-20 ~7 448 ~escribes the
addition of a mixture consisting of polyvinylethers and ethylene-
vinylacetate-copolymers to paraffin based crude oils.
Middle distillates are described in ~uropean Patent
Disclosure EP-A-360 419, which contain polymers of vinylethers
with hydrocarbon radicals o~ 1 to 17 carbon atoms. Alkylacrylates
or -methacrylates, among others, are disclosed as co-monomers.
However, the examples only describe polymers of alkylvinylethers
with up to four carbon atoms in the side chain. These C1- to C4-
vinylethers are copolymerized with derivatives of maleic or
~umaric acid. No examples of copolymers with d~rivatives of
acrylic acid are provided. The claimed additive-; can be used in
conjunction with other flow improvers.
However, these polymers leave a lot to b6 desired in regard
to their effectiveness as cold flow improvers for middle
distillates.
For these reasons the problem arose of filding additives to
middle distillates with improved efficiency as cold flow
improvers.
OBJECT AND SUMMARY OF THE INVENTION
It has been found accordingly that crude oil middle
distillates containing small amounts of A: known flow improvers,
and B: copolymers consisting to at least 70% by weight of one or a
plurality of monomers of both the Formula I as well as II
Rl '
H2C=C-COOR2 and H2C=CH-o-R3
(I) (II)
r.~here
Rl is hydrogen or m~thyl,
R2 is a C8 to C18 alkyl, and
R3 is a C18 to C28 alkyl,
fulfill these re~uirements.
The quantitative proportion of monomers according to
Formula I to monomers according to Formula II lies between 10:90
and 95O5, preferably between 40:60 and 95:5, ancl particularly
preferred between 60:40 and 90:10, and the ratio of -the flow
improver A to the copolymer B lies between 40.60 and 95:5,
pre~erably between 60:40 and 95:5 and particularly preferred
between 70:30 and 90:10.
The alkyl radicals R2 and R3 are preferably straight-chains
and linear. However, up to 20~ by weight of cyclic and/or
branched portions may also be included.
Examples of monomers in accordance with ~ormula I are n-
octyl(meth~acrylate, n-decyl(meth)acrylate, n-dcdecyl(meth)-
acrylate, n-tetradecyl(meth)acrylate, n-hexadecyl(meth)acrylate
and n-octadecyl(meth)acrylate, as well as mixtures ~hereof.
Examples for monomers in accordance with Formula II are n-
octadecylvinylether, n-eicocylvinylether, n-dococylvinylether, n-
tetracocylvinylether, n-hexacocylvinylether and n-octacocylvinyl-
ether, as well as mixtures thereo~.
The copolymers B consist of monomers in accordance with
Formula I and II to at least 70% by weight. Additionally, up to
30% by weight of other ethylenically unsaturate~.? monomers may be
present, such as styrols, alkylstyrols, straight--chain or branched
olefins with 2 to 16 carbon atoms, vinylesters of C1- to C5-
carboxylic acids, acrylnitrile, N-alkyl substitut:ed acrylamides,
N-containing, ethylenically unsaturated heterocyclenes, such as
vinylpyrrolidone, vinylimidazole or vinylpyridine, monomers
con~aining hydroxil or amino groups such as but~nediolmono-
.
acrylate, hexandiolmonoacrylate, dimethylaminoethylacrylate,diethylaminoethylacrylate, as well as (meth)acrylic acid ester of
Cl- to C6-alkanols such as methylmethacrylate, ethylacrylate,
isobutylacrylate and others, as well as maleic acid, ~umaric acid
and itaconic acid esters of Cl- to C28-alkanols.
Examples of the flow improvers A are the already mentioned
polymers described in DE-A-21 02 469 and EP--A-84 148, and
copolymers of ethylene with vinylacetate, vinylpropionate,
vinylbutyrate, vinylpivalate or with esters of (meth)acrylic acid
which derive from alkanols with 1 to 12 carbon a~oms. Also
suitable are mixtures of several copolymers of ethylene and
vinylacetate (EP-A-261 951, Additive A), copolymers of ethylene
with ~-olefins (EP-A-261 957, Additive D) and the mixtures of
terpolymers of ethylene, vinylacetate and diisohutane with
oxidized polyethyiene wax recited in DE-A-3~ 24 1~7. Copolymers
of ethylene with vinylacetate or vinylpropionate or ethylhexyl-
acrylate are particularly preferred.
The copolymers show synergistic effects together with the
flow improvers. Although the copolymers B by themselves show no
or only little improvement of the flow, the combination of A and B
far exceeds the individual effects.
The monomers in accordance with Formula I are easily
accessible. They can be obtained by means of the known methods of
esterification. For example, a solution of (meth)acrylic acid and
an alkanol or a mixture of different alkanols is heated to boiling
in an organic solvent with the addition of ths usual
polymerization inhibitors, for example hydroquirone derivatives
and esterification catalysts, such as sulfuric acid, p~toluene
sulfonic acid or acid ion exchangers, and the r6action water which
forms is removed by azeotropic distillation. Because vinylethers
can cationically polymerize under acid condition- or decompose in
the presence of water while forming acetaldehyde, which upsets the
.
2 ~
polymerization of the radicals, neutralization oE the catalyzer
acid as well as surplus (meth)acrylic acid with, ~or example,
amines, or their removal by washing of the estet solution w1th
alXaline means and water for producing the copolymers B is
indicated. Particularly pure esters can be obtained by
distillation of the pre-cleaned ester solution.
Further possibilities for producing the monomers in
accordance with Formula I are the reaction of (meth3acrylic acid
chloride or anhydride with the corresponding alhanols as well as
the reaction, known as interesterification of low (meth)acrylic
acid esters with the corresponding C8- to C18 alkanols, with the
addition of acidic or basic catalysts and removal by distillation
of the low alkanol. In this production method the ester should
also be processed sufficiently so that no more acid is present.
The vinylethers in accordance with Formula II can be
obtained in accordance with known methods by the reaction of
alkanols with acetaldehyde and subsequent splitt.ing off of water
or by means of the catalytic addition of acetylene to alkanols.
Particularly clean monomers can here also be obtained by
distillation~ Undecomposed distillation is technically di~ficult
to perform with vinylethers with more than 20 to 22 carbon atoms.
In these cases purification by filtration, extraction or
recrystallization to remove the catalysts is to ~e recommended.
The production o~ the copolymers B takes place in
accordance with known discontinuous or continuo~s polymerization
methods, such as mass, suspension, precipitation or solution
polymerization, and initiation with the usual radical donors, such
as acetylcyclohexanesulfonylperoxide, diacetylperoxidicarbonate,
dicyclohexylperoxidicarbonate, di-2-ethylhexylperoxidicarbonate,
tert.-butylperneodecanoate, 2,2'-azobis(4-methoxy-2, ~-dimethyl-
valeronitrile), tert.-butylperpivalate, tert.-butylper-2-ethyl-
hexanoate, tert.-butylpermaleinate, 2,2'-azobis(isobutyronitril),
1 8
bis-(tert~-butylperoxide)cyclohexane~ tert.-bukylperoxiisopropyl-
carbonate, tert.-butylperacetate, di-cumylperoxide, di-tert.-
amylperoxide, p-menthanehydroperoxide, cumolhydroperoxide or
tert.-butylhydroperoxide and mixtures among these. Generally
these initiators are used in amounts of 0.1 to 20% by weighk,
preferably 0.2 to 15% by weight, in respect to the monomers.
Polymerization as a rule takes place at temperatures of 40
to 400C, preferably 70 to 300C, where it is practical to
operate under pressure when solvents with boiling temperatures
below the polymerization temperature are used. It is practical
to perform the polymerization with air excluded, i.e. if
processing is not done under boiling conditions, for example in
nitrogen or carbon dioxide, because oxygen delays polymerization.
The reaction can be accelerated by the simultaneous use of redox
initiators, such as benzoin, dimethylaniline, ascorbic acid as
well as organically soluble complexes of heavy metals such as
copper, cobalt, manganese, iron, nickel and chromium. The
amounts normally used lie around 0.1 to 2000 ppm by weight,
preferably 0.1 to lO00 ppm by weight. When selecting the
initiator or the initiator system, it is practical in connection
with the chosen polymerization temperature to see to it that the
half-time of the initiator or initi~tor system is less than four
hours.
It is often practical for obtaining low-molecular copolymers
to operate in the presence of regulators. Suitable regulators
are, ~or example, allylalcohols such as l-butene-3-ol, organic
mercaptan compounds such as 2-mercaptoethanol, 2-mercapto-
propanol, mercaptoacetic acid, mercaptopropionic acid, tert.-
butylmercaptan, n-butylmercaptan, n-octylmercaptan, n-dodecyl-
mercaptan and tert.-dodecylmercaptan, which generally are used in
amounts of 0.1 to 10% by weight.
Apparatus suitable for polymerization consists o~, for
example, customary mixing vessels with, for example, anchor
--7--
2 ~ 8
blade, impeller or multistage-pulse countercurrent agitators, and
for continuous production mixing vessel cascades, tube reactors
and static mixers.
Mass polymerization is the simplest polymerization method.
In accordance with it the monomers are polymerized in the presence
of an initiator and the absence of solvents. In a practical
manner all monomers are mixed in the desired composition and a
small amount, for example approximately 5 to 10%, is first placed
into the reactor, heated to the desired polymer;zation temperature
while stirring and the remaining monomer mixture and the initiator
and, if required, the coinitiator as well as the regulator are
evenly admixed during 1 to 10 hours, preferably ~ to 5 hours. In
this connection it is practicable to admix the initiator as well
as the coinitiator separately in the form of solutions in a small
amount of a suitable solvent. Then the copolyme~ can be added
directly to the flow improver as a solidified molten mass or after
having been placed in a suitable solvent.
A continuous high-pressure method is also suitable for
producing the desired copolymers, which permits space-time yields
of 1 to 50 kg polymer per liter of reactor and nour. For example,
a pressure vessel, a pressure vessel cascade, a ~ressure pipe or a
pressure vessel with a reaction pipe downstream, which is provided
with a static mixer, can be used as polymerization apparatus.
Polymerization is preferably performed with moncmers of
(meth)acrylic acid esters and vinylethers in at least two
successive polymerization zones. One polymerization zone can
consist of a pressure-proof vessel, the other of a heatable static
mixer. Conversions of more than 99% are obtained in this case.
For example, a copolymer of (meth)acrylic acid esters and
vinylethers can be produced by continuously supplying the monomers
and a suitable initiator to a reactor ot two successive reaction
zones, for example a reactor cascade, and continuously taking the
-8-
~ ~$ ~ 8
reaction product ~rom the reaction zone after a loitering time of
2 to 60, preferably 5 to 30 minutes, at ~emperatures between 200
and 400C. Pol~merization is practically performed at pressures
of more than 1 bar, preferably between 1 and 200 bar. The
copolymers obtained show solid contents of more than 99% and can
be supplied to ~he middle distillate without further treatment.
Another simple me~hod for producing the aopolymers B is
solution polymerization. It is performed in solvents in which the
monomers and the formed copolymers are soluble. For this all
those solvents are suitable which ~ulfill this condition and which
do not react with the monomers. They are, for example, toluene,
xylene, ethylbenzene, cumene, high-boiling aromatic mixtures such
as SolvessoR 100, 150 and 200, aliphatic and cycloaliphatic
hydrocarbons such as n-hexane, cyclohexane, methylcyclohexane, n-
octane, iso-octane, paraffin oil~, ShellsolR TD, T and K as well
as tetrahydrofuran and dioxane, where tetrahydrofuran and dioxane
are particularly well suited for obtaining low-molecular
copolymers. When performing the solution polymerization it is
practical to place the solvent and a part of the monomer mixture
(for example approximately 5 to 20%) first and to admix the
remainder of the monomer mixture with the initia~or and, if
required, the coinitiator, re~ulator and solvent It is also
possible to admix the monomers individually at different speeds.
This is recommended in case o~ monomers with greatly differing
reactivity, such as is the case with (meth)acrylates and
vinylethers, and when a particularly even distribution of the less
reactive vinylether is desired. In this case the less reactive
monomer is admixed faster and the more reactive monomer slower.
It is also possible to place the entire amount o~ a monomer,
preferably the less reactive vinylether, first and to admix only
the (meth)acrylate. Finally, i~ is also possib]e to place all the
monomers and the solvent first and to admix only the initiator
2 ~ 1 8
and, if required, the coinitiator and regulator (batch
processing). When using this type of processing on a larger
scale, however, problems in regard to heat removal may occur, so
that this type of processing should only be used with low
concentrations of the monomers to be polymerized. The
concentration of the monomers to be polymerized lies between 20
and 80% by weight, preferably 30 and 70% by weight. The solid
copolymers can be obtained without problems by evaporation of the
solvent. Howaver, it is practical to select a solvent for
polymerization which is compatible with the middle distillate, so
that the polymerisate solution can be directly added to the middle
distillate. Solution polymerization is the preferred type of
producing copolymers from (meth)acrylates and vinylethers.
There is the requirement in technology to provide the
additives in accordance with the invention, consisting of a flow
improver A and a copolymer B, in a form which is easy to handle.
For this purpose the polymers A and B should be available in the
form of one concentrate, since the use of two concentrates - one
each for polymer A and polymer B - makes handling more difficult.
Because of possible incompatibility of the polymers A and B, phase
separation may occur if the two polymers are purely admixed in a
common solvent. If necessary this can be suppressed by means of
suitable solvents and/or additives. For example, alkanols, such
as iso-butanol, n-hexanol, 2-ethylhexanol, iso-decanol and their
adducts with ethylene oxide, propylene oxide and/or butylene
oxide, alkylphenol and their adducts with ethylene oxide,
propylene oxide and/or butylene oxide, as well as semi-esters or
di-esters of dicarboxylic acids with alkanols or (oligo)alkylene-
oxide semi-esters such as mono or dibutylphthal~te, mono- or di-2-
ethyl-hexylphthalate or di-(2-methoxyethyl)-phthalate are
suitable.
--10--
2 ~ 8
Another method o~ preventing possible phase separa~ion
consists in gra~ting the copolymer B at least in part on the flow
improver. Mass or solution polymerization is pre~erably used ~or
grafting. Polymerization can be performed in accordance with
batch or feed processing. With batch processing, the entire
amount of flow improver A on which the graft is to be made is
placed first, together with the monomers, and the initiator and,
if required, the coinitiator and regulator are admixed later.
With feed processing, the entire amount o~ flow lmprover A on
which the graft is to be made is placed first, if desired together
with a portion of the monomers, and the rest of the monomers,
initiator and, if re~uired, the coinitiator and ~egulator are
admixed later.
As already mentioned, it is not necessary to graft the
copolymer B on the entire portion of the flow improver A. For
example, at the ratio A:B of 90:10, the copolymer B is grafted on
only a portion of 2 to 20% by weight of the entire amount of A for
reasons of the space-time yield. However, at a ratio of A:B of
40:60 on a portion o~ 30 to 100% by weight of the total amount of
A.
It is also unnecessary to graft the entire amount of polymer
B on a portion of the flow improver A. This is ~ifficult anyway,
because in general the graft yield does not reach 100%, so that it
is possible that, besides graft copolymerisates and unreacted or
admixed flow improver A, there is also non-grafted copolymer B in
the concentrates described.
The K values (according to ~. Fikentscher, Cellulose
Chemistry, Vol. 13, pp. 58 to 64 and 71 to 74 (1~32)), determined
in a 2% (vol. by weight) xylolic solution of the copolymerisates
B, lies between 10 and 50, preferably between lC and 40 and
particularly preferred between 13 and 30. The particularly
preferred range corresponds to molecular weights between
--11--
2 ~ 8
approximately 5000 and 25000 g/mol (numerical mean values
determined by gel permeation chromatography ayainst polystyrol
standards).
The additives A and B in accordance with the invention are
added to crude oil middle distillates in amounts of 50 to 5000
ppm, preferably 100 to 2000 ppm.
The middle distillates in accordance with the invention and
containing small amounts of a flow improver A and a copolymer B
may, depending on their inténded use, contain other additives or
added materials such as dispersants, anti-foaming additives,
corrosion protection agents, anti-oxidants, dyes, and the like.
The invention will be explained by means of the following
examples.
DETAILED DESCRIPTION
Production of Copolymers B in Accordance with the Invention
Example 1
In a reactor provided with an agitator, heater and feed
device, 144 g laurylacrylate, 16 g n-octadecylvinylether, 0.16 g
2-mercaptoethanol, 65 g triethylamine and 69 g toluene were heated
in a weak nitrogen flow to 100C while being agitated and a
solution of 0.64 g tert.-butylper-2-ethylhexanoa~e in 38.2 g
toluene was evenly admixed in the course of 4 hollrs. Subsequently
heating was continued at 100C and the mixture thinned with
approximately 54 g toluene. A clear, yellowish solution of
approximately 50~ by weight was obtained. The ~ value o~ the
polymer was 24.8.
-12-
2 ~
Example 2
In a reactor in accordance with Example 1, 1~4 g lauryl-
acrylate, 16 g n-octadecylvinylether and ~j8.6 g ~olvessoR 150 ~a
high-boiling aromatic mixture of the ESS0 compar.y) were heated in
a weak nitrogen flow to 80C while being agitated and a solution
of 0.48 g azoisobutyronitrile in 30 g SolvessoR 150 was evenly
admixed during a period of 4 hours. Subsequently a solution of
0.16 g azoisobutyronitrile in 8.5 g SolvessoR 150 was added,
heating continued at 80C for two hours and the mixture thinned
with 53.5 g SolvessoR 150. A clear, colorless, viscous polymer
solution of approximately 50% by weight was obtai~ed. The K value
of the polymer was 28.3.
Example 3
In a reactor in accordance with Example 1, 29.2 g lauryl-
acrylate, 7.3 g n-octadecylvinylether and 55.4 g ShellsolR K (a
high-boiling mixture of n- and iso-paraffin of the ESSO company)
were heated in a weak nitrogen flow to 100C while being agitated
and, in the course of two hours, a solution of 102.1 g lauryl-
acrylate, 26.0 g n-vinyloctadecyl-ether and 14.6 g ShellsolR K
and, in the course of four hours, a solution of ~.5 g tert.-
butylper-2-ethylhexanoate in 25 g ShellsolR K were admixed evenly.
Subsequently a solution of 0.17 g tert.-butylper-2-ethylhexanoate
in 4.2 g ShellsolR X were added, heating continued at 100C for an
hour and the mixture was thinned with 67.5 g ShellsolR XO A
clear, colorless, slightly viscous polymer solution was obtained.
The K value of the polymer was 19.6.
Examples 4 to 18 were produced in a manner analog to that
of Example 3.
1 8
Table
Ex- Prefeed Feed 1Feed 2 Acrylate T K value
ample (g) (g) (g) to vinyl- (C)
No. ether
4 43.2 LA116.8 LA 0.6 TBPO 80/20100 21.8
10.8 v18 29.2 v18 30.0 SK
60.0 SK16.0 SK
54.0 LA106.0 LA 0.6 TBPO 80/2090 30.0
40.0 v18 12.0 SK 30.0 SK
69.0 SK
6 98.9 LA390.6 hA 2.2 TBPO 67/33100 17.2
49.5 v18 195.3 v18 173.3 SK
149.0 SK65.8 SK
7 83.3 LA334.7 LA 2.2 TBPO 56/44100 16.4
65.2 v18 261.8 v18 179.0 SK
149.0 SK65.8 SK
8 59.4 LA238.6 LA 2.2 TBPO 40/6095 15.8
89.0 v18 357.9 v18 179.0 SK
149.0 SR65.8 SK
9 153.6 LA358.4 LA 2.0 TBPO 80/20100 24.5
38.4 v1822 89.6 v1822 96.0 SK
193.8 SR49.3 SK
as in Example 9, but with v20+80/20 100 19.8
instead of v1822
-14-
2a~ s
11 as in Example 9, but with A8-18 80/20 ~00 22.1
instead of LA
12 7.9 LA 82.1 LA 0.3 TP0 100 23.2
20.0 v18 8.9 vpr 16.0 toluene
1.1 vpr 8.9 toluene
18.0 toluene
13 as in Example 12, but with diethylamino- 100 25.2
ethylacrylate instead of vpr
14 as in Example 12, but with styrol 100 37.4
instead of vpr
as in Example 12, but with isobutylacrylat.e 100 25.2
instead of vpr
16 as in Example 12, but with vinylpyrrolidone 100 23.6
instead of vpr
17 120.0 LA 480.4 LA 1.8 TBP0 100 24.5
Com- 143.0 SK 247.6 SK 100.0 SK
parison
test
18 151.4 LA 408.6 LA 2.1 AIBN 80/20 85 23.7
Com- 37.8 v4 101.2 v4 105.0 toluene
paris- 209.8 C-hex 56.2 C-hex
on test
acc. to EP-A-360 419
` % ~
LA Laurylacrylate = n-alkylacrylate mixture, prepared from a
commercially available fatty alcohol mixture consisting of
max. 1.5% by weight of n-decanol, 51 ko 57% by weight of n-
dodecanol, 41 to 47% by weight o~ n-tetradecanol and max.
1.5% by weight of n-hexadecanol
A8-18 n-alkylacrylate mixture, prepared from a commercially
available fatty alcohol mixture consisting of 5 to 8% by
weight of n-octanol, 5 to 7% by weight of n-decanol, 44 to
50% by weight of n-dodecanol, 14 to 20% ky weight of
tetradecanol, 8 to 10% by weight of n-hexadecanol and 8 to
12% by weight of n-octadecanol
v18 n-octadecylvinylether
v1822 n-alkylvinylether mixture, prepared from a commercially
available fatty alcohol mixture consisting of 41 to 43% by
weight of n-octadecanol, 9 to 13% by weiyht of n-eicosanol
and 43 to 46% by weight of n-docosanol
v20+ n-alkylvinylether mixture, prepared from a commercially
available fatty alcohol mixture consistin~ of max. 6% by
weight of n-octadecanol, 40 to 60% by wei~ht of n-eicosanol,
23 to 35% by weight of n-docosanol, 10 to 18% by weight of
tetracosanol and 2 to 8% by weight of n-hexacosanol
vpr Vinylpropionate
SK ShellsolR K
-16-
` 2 ~
v i-4 Isopropylvinylether
C-hex Cyclohexane
TBPO tert.-butylper-2-ethylhexanoate
AIBN Azoisobutyronitrile
Example 19 (Comparison kest analog to EP-A-360 419, Example
C4)
In a reactor in accordance with Example 1, 51.4 g (aprx. 0.1
mol) of di-n-tetradecylfumarate and 10.0 g (o.l mol) of n-butyl-
vinylether were heated to 90C in a weak nitrogen flow while being
agitated. Then 0.4 g AIBN were added and polymerization performed
for 6 hours while further adding 0.1 g AIBN every hour. A viscous
polymer solution of 99% by weight with a K value of 11.5 was
obtained.
Example 20 (Comparison test analog to DE-A-16 45 785)
In a reactor in accordance with Example 1, first 1.5 g
borotrifluoride-etherate in 187.5 g toluene were placed and a
solution of 90 g n-octadecylvinylether in 22.5 g toluene were
evenly added at 30C over the period of one hour, agitation
performed for another 10 minutes and polymerization stopped by the
addition of 5 ml methanol. The polymer solution was precipitated
in acetone and dried in a vacuum. The K value was 15.4.
Examples 17 to 20 are comparison tests an-l not a part of
the present invention.
-17-
... :: .~ ..................... . . :.,, , ~;
-
2 ~ 8
Example 21
Grafting of laurylacetate and n-octadecylvinylether on a
flow improver consisting of 60% by weight of ethyl~ne and ~0~ by
weight of vinylpropionate with a mean molecular weight of
ap~roximately 2500 (determined by means of vapor pressure
osmometry) = FI(A).
In a reactor in accordance with Example 1, 215 g of the
flow improver FI(A) and 86 g ShellsolR K were heated in a weak
nitrogen flow to 100c while being agitated. A mixture of 516 g
laurylacrylate, 12~ g n-octadecylvinylether and 73.1 g ShellsolR K
were added to this and the remainder of the mixture was evenly
added over a period of two hours. Simultaneously 1.94 g tert.-
butylper-2-ethylhexanoate, dissolved in 64.5 g ShellsolR K, were
evenly added over a period of four hours. Subsequently a solution
of 0.65 g of tert.-butylper-2-hexanoate in 21.5 g ShellsolR K were
added, heating continued for an hour and the mixture was thinned
with 615 g SolvessoR 150 (high-boiling aromatic mixture of the
ESSO company). A slightly cloudy polymer solution of S0% by
weight with a K value of 25.2 was obtained. 80 g of this were
mixed with 110 g FI(A) and 110 g SolvessoR 150 at 60C. A mixture
which was cloudy at room temperature was obtained, which consists
of a total of approximately 80 parts of flow improver FI(A) and 20
parts of copolymer B. The mixture is stable at ~-oom temperature
for more than 10 weeks.
-18-
2 ~ 8
Application Examples
The following meanings apply ko what follows:
FI Flow improver, in particular
FI(A) Ethylene/vinylpropionate (with aprx. 40~ by weight
of vinylpropionate) of a mean molecular weight of
approximately 2500 (determined by vapor pressure
osmometry)
FI(B) Ethylene/vinylpropionate (with aprx. 30% by weight
of vinylpropionate) of a mean molecular weight of
approximately 2500
FI(C) Ethylene/vinylacetate (with aprx. 30% by weight
of vinylpropionate) of a mean molecular weight of
approximately 2500
The ~low improvers FI(A), FI(B) and FI(C) are commercially
available products, for example the KerofluxR brands of BASF.
Heating oil and Diesel fuel of a quality commercially
available in West Germany were used as middle distillates. They have
been designated as middle distillates I, II, III and IV.
19--
. . .
Middle Distillate
. I II III IV
Cloud point (C) ~6 +4 ~4 ~5
CFPP (C) 0 -2 -1 -2
Initial boiling point (C) 155 131 169 174
20~ boiling point (C) 232 216 222 219
50% boiling point (C) 280 262 262 272
90% boiling point (C) 352 346 351 365
Final boiling point (C) 382 375 331 385
Test Method
The cold filter plugging point (CFPP) in accordance with
DIN 51 428 was measured. The results are combined in the Table
below.
TablP
Test AdditiveDosage CFPP (C) in the Middle Distillate
No. (ppm)*
I II ,]II IV
1 Without - 0 (-2) (-1) (-2)
2 FI(A) 300 (~3~ (-2) ~-2) (-2)
3 FI(A) 500 (~3) (-2) (-1) (-3)
4 FI(B) 500 (-3) - (~4) (-2)
FI(C) 500 (-3) (-4) ~~5) (-2)
6 Copolymer 3 500 (+2) - - -
7 FI(A) 400 (-14) - _ _
Copolymer 1 100
-20-
8 FI(A) 400 (-13) - _ _
Copolymer 2 100
g FI(A) 300 (-10)
Copolymer 3 200
FI(A) 400 (-16) - _ _
Copolymer 3 lO0
11 FI(A) 450 (-14)
Copolymer 3 50
12 FI(A) 475 (-14)
Copolymer 3 25
13 FI(A) 160 - _ (-15)
Copolymer 4 40
14 FI(A) 240 (-13)(-16) _ (-14)
Copolymer 4 60
FI(A) 320 - - (-16)
Copolymer 4 80
16 FI(A) 400 (-16)(-17) _ (-15)
Copolymer 4 100
17 FI(A) 160 - - ~-14)
Copolymer 5 40
18 FI(A) 240 (-14)(-14) ~ (-13)
Copolymer 5 60
19 FI(A) 320 - _ ~ (-16)
Copolymer 5 80
FI(A) 400 (-15)(-16) ~ (-16)
Copolymer 5 100
21 FI(A) 400 (-14) _ _ _
Copolymer 6 100
22 FI(A) 400 (-14) - - -
Copolymer 7 lO0
23 FI(A) 400 ¢-14) - - -
Copolymer 8 100
-21-
2 ~ 1 8
24 FI(A) 400 (-12)
Copolymer 9 100
FI(A) . 400 (-10)
Copolymer 10 100
26 FI(~) 400 (-13) - - -
Copolymer 11 100
27 FI(A) 400 (~13) - - -
Copolymer 12 100
28 FI(A) 400 (-15
Copolymer 13 100
29 FI(A) 400. (-10)
Copolymer 14 100
FI(A) 400 (-13)
Copolymer 15 100
31 FI(A) 400 (-15)
Copolymer 16 100
32 FI(B) 240 (-10) (-14) _ (-12)
Copolymer 4 60
33 FI(B) 400 (-10) (-15) (-12)
Copolymer 4 100
34 FI(B) 160 - - (-12)
Copolymer 4 40
FI(B) 320 ~ ~ , (-13)
Copolymer 4 80
36 FI(B) 240 (-10) (-15) ~ (-11)
Copolymer 5 60
37 FI(B) 400 (-10) (-16) ~ (-12)
Copolymer 5 100
38 FI(B) 160 - _ (-11) _
Copolymer 5 40
39 FI(B) 320 - - (-13)
Copolymer 5 80
22-
2 0 ~
Copolymer 21 500 (-16) _ _ _
41 FI(C) 400 (-13)
Copolymer 4 100
Comparison Tests
42 FI(A) 400 (-1) - _ _
Copolymer 17 100
43 FI(A) 400 (-1)
Copolymer 18 loo
44 FI(A) 400 (-1)
Copolymer 19 loo
FI(A) 400 (~5)
Copolymer 20 loO
* in relation to solutions of 50~ by weight of FI(A), FI(B)
and FI(C) as well as of the copo~ymers in, for example, SolvessoR
150.
As shown by the above examples, the conventional flow
improvers FI(A), FI(B) and FI(C) show unsatisfactory effects in
the middle distillates. Adding only the copolymers of the
invention even worsens the CFPP of the middle.distillates. The
synergistic effect of the flow improvers and the copolymers of the
invention are made clear by Examples 7 to 40.
As shown in the comparison tests, neithex the polyacrylate
(Example 42) nor the polyvinylether (Example 45)~ together with
the conventional flow improvers, show satisfactory lowering of
the CFPP. Also, the copolymers with short-chain vinylethers
(Examples 43 and 44) described in EP-A-360 419 have shown
themselves to be ineffective in connection with the above oils,
while the copolymerisates of the invention o~ a~kylacrylates,
-23-
- . . : . . . - : .
.
` 2 ~ 8
long-chain vinylethers and, if required, an additional monomer in
combination with FI(A), FI(B) or ~I(C) clearly lower the CFPP at
small dosages.
-24-
