U.S. patent application number 11/009870 was filed with the patent office on 2005-06-16 for fuel oils composed of middle distillates and oils of vegetable or animal origin and having improved cold flow properties.
This patent application is currently assigned to Clariant GmbH. Invention is credited to Hess, Martina, Krull, Matthias, Siggelkow, Bettina.
Application Number | 20050126071 11/009870 |
Document ID | / |
Family ID | 34485304 |
Filed Date | 2005-06-16 |
United States Patent
Application |
20050126071 |
Kind Code |
A1 |
Krull, Matthias ; et
al. |
June 16, 2005 |
Fuel oils composed of middle distillates and oils of vegetable or
animal origin and having improved cold flow properties
Abstract
The invention provides a fuel oil composition F) comprising F1)
89-50% by volume of a fuel oil of mineral origin and F2) 11-50% by
volume of a fuel oil of vegetable and/or animal origin, and, as a
cold additive, the constituents A) at least one copolymer composed
of ethylene and 8-21 mol % of at least one acrylic or vinyl ester
having a C.sub.1-C.sub.18-alkyl radical and B) at least one comb
polymer containing structural units composed of B1) at least one
olefin as monomer 1 which bears at least one C.sub.8-C.sub.18-alkyl
radical on the olefinic double bond, and B2) at least one
ethylenically unsaturated dicarboxylic acid as monomer 2 which
bears at least one C.sub.8-C.sub.16-alkyl radical bonded via an
ester moiety, where the sum Q 1 Q = i w 1 i n 1 i + j w 2 j n 2 j
of the molar averages of the carbon chain length distributions in
the alkyl radicals of monomer 1 on the one hand and the alkyl
radicals of the ester groups of monomer 2 on the other is from 21.0
to 28.0, where w.sub.1 is the molar proportion of the individual
chain lengths in the alkyl radicals of monomer 1, w.sub.2 is the
molar proportion of the individual chain lengths in the alkyl
radicals of the ester groups of monomer 2, n.sub.1 are the
individual chain lengths in the alkyl radicals of monomer 1,
n.sub.2 are the individual chain lengths in the alkyl radicals of
the ester groups of monomer 2, i is the serial variable for the
individual chain lengths in the alkyl radicals of monomer 1, and j
is the serial variable for the individual chain lengths in the
alkyl radicals in the ester groups of monomer 2.
Inventors: |
Krull, Matthias; (Harxheim,
DE) ; Siggelkow, Bettina; (Oberhausen, DE) ;
Hess, Martina; (Muelheim a. d. Ruhr, DE) |
Correspondence
Address: |
CLARIANT CORPORATION
INTELLECTUAL PROPERTY DEPARTMENT
4000 MONROE ROAD
CHARLOTTE
NC
28205
US
|
Assignee: |
Clariant GmbH
|
Family ID: |
34485304 |
Appl. No.: |
11/009870 |
Filed: |
December 10, 2004 |
Current U.S.
Class: |
44/393 ;
44/605 |
Current CPC
Class: |
C10L 1/143 20130101;
C10L 1/1955 20130101; C10L 1/1973 20130101; C10L 1/224 20130101;
C10L 1/19 20130101; C10L 1/146 20130101; C10L 1/1966 20130101; C10L
1/221 20130101 |
Class at
Publication: |
044/393 ;
044/605 |
International
Class: |
C10L 001/18; C10L
005/00 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 11, 2003 |
DE |
103 57 877.3 |
Claims
1. A fuel oil composition F) comprising F1) 89-50% by volume of a
fuel oil of mineral origin and F2) 11-50% by volume of a fuel oil
of vegetable and/or animal origin, and a cold additive comprising
the constituents A) at least one copolymer composed of ethylene and
8-21 mol % of a comonomer of at least one acrylic or vinyl ester
having a C.sub.1-C.sub.18-alkyl radical and B) at least one comb
polymer containing structural units composed of B1) at least one
olefin as monomer 1 which bears at least one C.sub.8-C.sub.18-alkyl
radical on the olefinic double bond, and B2) at least one
ethylenically unsaturated dicarboxylic acid as monomer 2 which
bears at least one C.sub.8-C.sub.16-alkyl radical bonded via an
ester moiety, where the sum Q 3 Q = i w 1 i n 1 i + j w 2 j n 2 j
of molar averages of the carbon chain length distributions in the
alkyl radical of monomer 1 on the one hand and the alkyl radical of
the ester moiety of monomer 2 on the other is from 21.0 to 28.0,
where w.sub.1 is a molar proportion of the individual chain lengths
in the alkyl radical of monomer 1, w.sub.2 is a molar proportion of
the individual chain lengths in the alkyl radical of the ester
groups of monomer 2, n.sub.1 are individual chain lengths in the
alkyl radical of monomer 1, n.sub.2 are individual chain lengths in
the alkyl radical of the ester moiety of monomer 2, i is a serial
variable for the individual chain lengths in the alkyl radical of
monomer 1, and j is a serial variable for the individual chain
lengths in the alkyl radical in the ester moiety of monomer 2.
2. A fuel oil composition as claimed in claim 1, wherein Q is from
22.0 to 27.0.
3. A fuel oil composition of claim 1, wherein the comonomer of
constituent A, comprises from 3.5 to 20 mol % of vinyl acetate and
from 0.1 to 12 mol % of a vinyl ester selected from the group
consisting of vinyl neononanoate, vinyl neodecanoate vinyl
2-ethylhexanoate, and mixtures thereof, the total comonomer content
of constituent A) being between 8 and 21 mol %.
4. A fuel oil composition of claim 1, wherein the comonomer of
constituent A comprises from 8 to 18 mol % of vinyl esters, and
further comprises from 0.5 to 10 mol % of olefins selected from the
group consisting of propene, butene, isobutylene, hexene,
4-methylpentene, octene, diisobutylene, norbornene, and mixtures
thereof.
5. A fuel oil composition of claim 1, wherein the copolymers which
make up constituent A have melt viscosities between 20 and 10 000
mPas.
6. A fuel oil composition of claim 1, wherein the copolymers which
make up constituent A have a degree of branching between 1 and 9
CH.sub.3/100 CH.sub.2 groups which do not stem from the
comonomers.
7. A fuel oil composition of claim 1, wherein constituent B
comprises monomers which are derived from esters or anhydrides or
mixtures of esters and anhydrides of an acid selected from the
group consisting of maleic acid, fumaric acid itaconic acid, and
mixtures thereof.
8. A fuel oil composition of claim 1, wherein the ester moiety of
constituent B are derived from alcohols having linear alkyl
radicals.
9. A fuel oil composition of claim 1, wherein an average molecular
mass of constituent B is between 1200 and 200 000 g/mol.
10. A fuel oil composition of claim 1, wherein constituent B
comprises monomers derived from .alpha.-olefins.
11. A fuel oil composition of claim 1, wherein a mixing ratio A:B
is between 10:1 and 1:10.
12. A fuel oil composition of claim 1, further comprising polar
nitrogen-containing paraffin dispersants.
13. A fuel oil composition of claim 1, which comprises 88-65% by
volume of F1 and 12-35% by volume of F2.
14. A fuel oil composition of claim 1, wherein the fuel oil of
animal or vegetable origin comprises one or more esters of a
monocarboxylic acid having from 14 to 24 carbon atoms and alcohol
having from 1 to 4 carbon atoms.
15. A fuel oil composition as claimed in claim 14, wherein the
alcohol is methanol or ethanol.
16. A fuel oil composition of claim 1, wherein the fuel oil of
animal or vegetable origin contains more than 4% by weight of
esters of saturated fatty acids.
17. A process for improving the cold flow properties of mixtures of
mineral fuel oils and fuel oils of animal or vegetable origin, said
process comprising adding to said mixtures a cold additive
comprising the constituents A) at least one copolymer composed of
ethylene and 8-21 mol % of a comonomer of at least one acrylic or
vinyl ester having a C.sub.1-C.sub.18-alkyl radical and B) at least
one comb polymer containing structural units composed of B1) at
least one olefin as monomer 1 which bears at least one
C.sub.8-C.sub.18-alkyl radical on the olefinic double bond, and B2)
at least one ethylenically unsaturated dicarboxylic acid as monomer
2 which bears at least one C.sub.8-C.sub.16-alkyl radical bonded
via an ester moiety, where the sum Q 4 Q = i w 1 i n 1 i + j w 2 j
n 2 j of molar averages of the carbon chain length distributions in
the alkyl radical of monomer 1 on the one hand and the alkyl
radical of the ester moiety of monomer 2 on the other is from 21.0
to 28.0, where w.sub.1 is a molar proportion of the individual
chain lengths in the alkyl radical of monomer 1, w.sub.2 is a molar
proportion of the individual chain lengths in the alkyl radical of
the ester groups of monomer 2, n.sub.1 are individual chain lengths
in the alkyl radical of monomer 1, n.sub.2 are individual chain
lengths in the alkyl radical of the ester moiety of monomer 2, i is
a serial variable for the individual chain lengths in the alkyl
radical of monomer 1, and j is a serial variable for the individual
chain lengths in the alkyl radical in the ester moiety of monomer
2.
18. A process for producing fuel oil compositions F comprising fuel
oils of mineral (F1) and animal or vegetable (F2) origin, having
improved cold flow properties, by adding an additive to the mixture
of fuel oils of mineral (F1) and animal or vegetable (F2) origin,
said additive comprising the constituents A) at least one copolymer
composed of ethylene and 8-21 mol % of a comonomer of at least one
acrylic or vinyl ester having a C.sub.1-C.sub.18-alkyl radical and
B) at least one comb polymer containing structural units composed
of B1) at least one olefin as monomer 1 which bears at least one
C.sub.8C.sub.18-alkyl radical on the olefinic double bond, and B2)
at least one ethylenically unsaturated dicarboxylic acid as monomer
2 which bears at least one C.sub.8-C.sub.16-alkyl radical bonded
via an ester moiety, where the sum Q 5 Q = i w 1 i n 1 i + j w 2 j
n 2 j of molar averages of the carbon chain length distributions in
the alkyl radical of monomer 1 on the one hand and the alkyl
radical of the ester moiety of monomer 2 on the other is from 21.0
to 28.0, where w.sub.1 is a molar proportion of the individual
chain lengths in the alkyl radical of monomer 1, w.sub.2 is a molar
proportion of the individual chain lengths in the alkyl radical of
the ester groups of monomer 2, n.sub.1 are individual chain lengths
in the alkyl radical of monomer 1, n.sub.2 are individual chain
lengths in the alkyl radical of the ester moiety of monomer 2, i is
a serial variable for the individual chain lengths in the alkyl
radical of monomer 1, and j is a serial variable for the individual
chain lengths in the alkyl radical in the ester moiety of monomer
2.
Description
[0001] The present invention relates to mineral fuel oils
comprising constituents of vegetable or animal origin and having
improved cold flow properties, and also to the use of an additive
as a cold flow improver for such fuel oils.
[0002] In view of decreasing world crude oil reserves and the
discussion about the environmentally damaging consequences of the
use of fossil and mineral fuels, there is increasing interest in
alternative energy sources based on renewable raw materials
(biofuels). These include in particular natural oils and fats of
vegetable or animal origin. These are generally triglycerides of
fatty acids having from 10 to 24 carbon atoms and a calorific value
comparable to conventional fuels, but are at the same time regarded
as being less harmful to the environment. Biofuels, i.e. fuels
derived from animal or vegetable material, are obtained from
renewable sources and, when they are combusted, generate only as
much CO.sub.2 as had previously been converted to biomass. It has
been reported that less carbon dioxide is formed in the course of
combustion than by the equivalent amount of crude oil distillate
fuel, for example diesel fuel, and that very little sulfur dioxide
is formed. In addition, they are biodegradable.
[0003] Oils obtained from animal or vegetable material are mainly
metabolism products which include triglycerides of monocarboxylic
acids, for example acids having from 10 to 25 carbon atoms, and
corresponding to the formula 1
[0004] where R is an aliphatic radical which has from 10 to 25
carbon atoms and may be saturated or unsaturated.
[0005] In general, such oils contain glycerides from a series of
acids whose number and type vary with the source of the oil, and
they may additionally contain phosphoglycerides. Such oils can be
obtained by processes known from the prior art.
[0006] As a consequence of the sometimes unsatisfactory physical
properties of the triglycerides, the industry has applied itself to
converting the naturally occurring triglycerides to fatty acid
esters of low alcohols such as methanol or ethanol.
[0007] A hindrance to the use of fatty acid esters of lower
monohydric alcohols as a replacement for diesel fuel alone has been
found to be its behavior toward engine parts, especially various
sealing materials, which lead time and time again to breakdowns of
the engines operated using these fuels produced from renewable raw
materials. To circumvent these problems, preference is given to
using these oils based on renewable raw materials as an additive to
conventional middle distillates.
[0008] In addition, when triglycerides and also fatty acid esters
of lower monohydric alcohols are used as a replacement for diesel
fuel, alone or in a mixture with diesel fuel, a hindrance has been
found to be the flow behavior at low temperatures. The causes of
this are in particular their content of esters of saturated fatty
acids and the high uniformity (less than 10 main components) of
these oils in comparison to mineral oil middle distillates. For
example, rapeseed oil methyl ester (RME) has a Cold Filter Plugging
Point (CFPP) of -14.degree. C., soya oil methyl ester a CFPP of
-5.degree. C., used fatty acid methyl ester a CFPP of +1.degree. C.
and animal fat a CFPP of +9.degree. C. It has hitherto often been
impossible using the prior art additives, on the basis of mineral
diesel comprising this ester or these esters, to reliably obtain a
CFPP value of -20.degree. C. required for use as a winter diesel in
Central Europe, or of -22.degree. C. or lower for special
applications. This problem is increased when oils are used which
comprise relatively large amounts of the likewise readily available
oils of sunflowers and soya.
[0009] EP-B-0 665 873 discloses a fuel oil composition which
includes a biofuel, a fuel oil based on crude oil and an additive
which comprises (a) an oil-soluble ethylene copolymer or (b) a comb
polymer or (c) a polar nitrogen compound or (d) a compound in which
at least one substantially linear alkyl group having from 10 to 30
carbon atoms is bonded to a nonpolymeric organic radical, in order
to provide at least one linear chain of atoms which includes the
carbon atoms of the alkyl groups and one or more nonterminal oxygen
atoms, or (e) one or more of components (a), (b), (c) and (d).
[0010] EP-B-0 629 231 discloses a composition which comprises a
relatively large proportion of oil which consists substantially of
alkyl esters of fatty acids which are derived from vegetable or
animal oils or both, mixed with a small proportion of mineral oil
cold flow improvers which comprises one or more of the
following:
[0011] comb polymer, the copolymer (which may be esterified) of
maleic anhydride or fumaric acid and another ethylenically
unsaturated monomer, or polymer or copolymer of .alpha.-olefin, or
fumarate or itaconate polymer or copolymer,
[0012] (II) polyoxyalkylene ester, ester/ether or a mixture
thereof,
[0013] (III) ethylene/unsaturated ester copolymer,
[0014] (IV) polar, organic, nitrogen-containing paraffin crystal
growth inhibitor,
[0015] (V) hydrocarbon polymer,
[0016] (VI) sulfur-carboxyl compounds and
[0017] (VII) aromatic pour point depressant modified with
hydrocarbon radicals,
[0018] with the proviso that the composition comprises no mixtures
of polymeric esters or copolymers of esters of acrylic and/or
methacrylic acid which are derived from alcohols having from 1 to
22 carbon atoms.
[0019] EP-B-0 543 356 discloses a process for preparing
compositions having improved low temperature performance for use as
fuels or lubricants, starting from the esters of naturally
occurring long-chain fatty acids with monohydric
C.sub.1-C.sub.6-alcohols (FAE), which comprises
[0020] a) adding PPD additives (pour point depressants) known per
se and used for improving the low temperature performance of
mineral oils in amounts of from 0.0001 to 10% by weight, based on
the long-chain fatty acid esters FAE and
[0021] b) cooling the nonadditized long-chain fatty acid esters FAE
to a temperature below the Cold Filter Plugging Point and
[0022] c) removing the resulting precipitates (FAN).
[0023] DE-A-40 40 317 discloses mixtures of fatty acid lower alkyl
esters having improved cold stability comprising
[0024] a) from 58 to 95% by weight of at least one ester within the
iodine number range from 50 to 150 and being derived from fatty
acids having from 12 to 22 carbon atoms and lower aliphatic
alcohols having from 1 to 4 carbon atoms,
[0025] b) from 4 to 40% by weight of at least one ester of fatty
acids having from 6 to 14 carbon atoms and lower aliphatic alcohols
having from 1 to 4 carbon atoms and
[0026] c) from 0.1 to 2% by weight of at least one polymeric
ester.
[0027] EP-B-0 153 176 discloses the use of polymers based on
unsaturated dialkyl C.sub.4-C.sub.8-dicarboxylates having an
average alkyl chain length of from 12 to 14 as cold flow improvers
for certain crude oil distillate fuel oils. Mentioned as suitable
comonomers are unsaturated esters, in particular vinyl acetate, but
also .alpha.-olefins.
[0028] EP-B-0 153 177 discloses an additive concentrate which
comprises a combination of
[0029] I) a copolymer having at least 25% by weight of an n-alkyl
ester of a monoethylenically unsaturated C.sub.4-C.sub.8 mono- or
dicarboxylic acid, the average number of carbon atoms in the
n-alkyl radicals being 12-14, and another unsaturated ester or an
olefin, with
[0030] II) another low temperature flow improver for distillate
fuel oils.
[0031] EP-B-0 746 598 discloses comb polymers as a cold additive in
fuel oils which have a cloud point of at most -10.degree. C.
[0032] It has hitherto often been impossible using the existing
additives to reliably adjust middle distillates comprising fatty
acid esters to a CFPP value of -20.degree. C. required for use as a
winter diesel in Central Europe or of -2.degree. C. and lower for
special applications. An additional problem with the existing
additives is lacking sedimentation stability of the additized oils.
The paraffins and fatty acid esters precipitating below the cloud
point sediment when the oil is stored below the cloud point for a
prolonged period and lead to the formation of a phase having poorer
cold properties on the bottom of the storage vessel.
[0033] It is thus an object of the present invention to provide
fuel oils having improved cold properties and comprising middle
distillates and fatty acid esters, their CFPP values being at
-20.degree. C. and below. Moreover, the sedimentation of
precipitated paraffins and fatty acid esters in the course of
prolonged storage of the fuel oil should be slowed or prevented in
the region of its cloud point or below.
[0034] It has now been found that, surprisingly, fuel oils composed
of middle distillates and oils of vegetable and/or animal origin,
which include an additive comprising ethylene copolymers and
certain comb polymers, exhibit excellent cold properties.
[0035] The invention thus provides a fuel oil composition F)
comprising
[0036] F1) 89-50% by volume of a fuel oil of mineral origin and
[0037] F2) 11-50% by volume of a fuel oil of vegetable and/or
animal origin, and, as a cold additive, the constituents
[0038] A) at least one copolymer composed of ethylene and 8-21 mol
% of at least one acrylic or vinyl ester having a
C.sub.1-C.sub.18-alkyl radical and
[0039] B) at least one comb polymer containing structural units
composed of
[0040] B1) at least one olefin as monomer 1 which bears at least
one C.sub.8-C.sub.18-alkyl radical on the olefinic double bond,
and
[0041] B2) at least one ethylenically unsaturated dicarboxylic acid
as monomer 2 which bears at least one C.sub.8-C.sub.16-alkyl
radical bonded via an ester moiety,
[0042] where the sum Q 2 Q = i w 1 i n 1 i + j w 2 j n 2 j
[0043] of the molar averages of the carbon chain length
distributions in the alkyl radicals of monomer 1 on the one hand
and the alkyl radicals of the ester groups of monomer 2 on the
other is from 21.0 to 28.0, where
[0044] w.sub.1 is the molar proportion of the individual chain
lengths in the alkyl radicals of monomer 1,
[0045] w.sub.2 is the molar proportion of the individual chain
lengths in the alkyl radicals of the ester groups of monomer 2,
[0046] n.sub.1 are the individual chain lengths in the alkyl
radicals of monomer 1,
[0047] n.sub.2 are the individual chain lengths in the alkyl
radicals of the ester groups of monomer 2,
[0048] i is the serial variable for the individual chain lengths in
the alkyl radicals of monomer 1, and
[0049] j is the serial variable for the individual chain lengths in
the alkyl radicals of the ester groups of monomer 2.
[0050] The invention further provides the use of the above-defined
additive comprising constituents A) and B) for improving the cold
properties of fuel oil compositions F) comprising fuel oils of
mineral (F1) and animal and/or vegetable (F2) origin.
[0051] The invention further provides a process for producing fuel
oil compositions F) comprising fuel oils of mineral (F1) and animal
and/or vegetable (F2) origin, having improved cold flow properties,
by adding the above-defined additive comprising constituents A) and
B) to the mixture of fuel oils of mineral (F1) and animal and/or
vegetable (F2) origin.
[0052] Preferred oils of mineral origin are middle distillates. The
mixing ratio between the fuel oils of animal and/or vegetable
origin (which are also referred to hereinbelow as biofuels) and
middle distillates is preferably from 88 to 65% by volume of middle
distillate and from 12 to 35% by volume of biofuel. The inventive
additives impart to these mixtures superior cold properties.
[0053] In a preferred embodiment of the invention, Q assumes values
between 22.0 and 27.0, in particular from 23.0 to 26.0 and, for
example, 23, 24, 24.5, 25 or 26.
[0054] Side chain length of olefins refers here to the alkyl
radical diverging from the polymer backbone, i.e. the chain length
of the monomeric olefin minus the two olefinically bonded carbon
atoms. In the case of olefins having nonterminal double bonds, for
example olefins having vinylidene moiety, the total chain length of
the olefin minus the double bond merging into the polymer backbone
correspondingly has to be taken into account.
[0055] Suitable ethylene copolymers A) are those which contain from
8 to 21 mol % of one or more vinyl and/or (meth)acrylic esters and
from 79 to 92 mol % of ethylene. Particular preference is given to
ethylene copolymers having from 10 to 18 mol %, and especially from
12 to 16 mol %, of at least one vinyl ester. Suitable vinyl esters
are derived from fatty acids having linear or branched alkyl groups
having from 1 to 30 carbon atoms. Examples include vinyl acetate,
vinyl propionate, vinyl butyrate, vinyl hexanoate, vinyl
heptanoate, vinyl octanoate, vinyl laurate and vinyl stearate, and
also esters of vinyl alcohol based on branched fatty acids, such as
vinyl isobutyrate, vinyl pivalate, vinyl 2-ethylhexanoate, vinyl
isononanoate, vinyl neononanoate, vinyl neodecanoate and vinyl
neoundecanoate. Likewise suitable as comonomers are esters of
acrylic and methacrylic acids having from 1 to 20 carbon atoms in
the alkyl radical, such as methyl (meth)acrylate, ethyl
(meth)acrylate, propyl (meth)acrylate, n- and isobutyl
(meth)acrylate, and hexyl, octyl, 2-ethylhexyl, decyl, dodecyl,
tetradecyl, hexadecyl and octadecyl (meth)acrylate, and also
mixtures of two, three, four or else more of these comonomers.
[0056] Particularly preferred terpolymers of vinyl
2-ethylhexanoate, of vinyl neononanoate or of vinyl neodecanoate
contain, apart from ethylene, preferably from 3.5 to 20 mol %, in
particular from 8 to 15 mol %, of vinyl acetate, and from 0.1 to 12
mol %, in particular from 0.2 to 5 mol %, of the particular
long-chain vinyl ester, the total comonomer content being between 8
and 21 mol %, preferably between 12 and 18 mol %. In addition to
ethylene and from 8 to 18 mol % of vinyl esters, further preferred
copolymers additionally contain from 0.5 to 10 mol % of olefins
such as propene, butene, isobutylene, hexene, 4-methylpentene,
octene, diisobutylene and/or norbornene.
[0057] The copolymers A preferably have molecular weights which
correspond to melt viscosities at 140.degree. C. of from 20 to 10
000 mPas, in particular from 30 to 5000 mPas, and especially from
50 to 1000 mPas. The degrees of branching determined by means of
.sup.1H NMR spectroscopy are preferably between 1 and 9
CH.sub.3/100 CH.sub.2 groups, in particular between 2 and 6
CH.sub.3/100 CH.sub.2 groups, for example from 2.5 to 5
CH.sub.3/100 CH.sub.2 groups, which do not stem from the
comonomers.
[0058] The copolymers (A) can be prepared by customary
copolymerization processes, for example suspension polymerization,
solution polymerization, gas phase polymerization or high pressure
bulk polymerization. Preference is given to carrying out the high
pressure bulk polymerization at pressures of from 50 to 400 MPa,
preferably from 100 to 300 MPa, and temperatures from 100 to
300.degree. C., preferably from 150 to 220.degree. C. In a
particularly preferred preparation variant, the polymerization is
effected in a multizone reactor in which the temperature difference
between the peroxide feeds along the tubular reactor is kept very
low, i.e. <50.degree. C., preferably <30.degree. C., in
particular <15.degree. C. The temperature maxima in the
individual reaction zones preferably differ by less than 30.degree.
C., more preferably by less than 20.degree. C. and especially by
less than 10.degree. C.
[0059] The reaction of the monomers is initiated by free
radical-forming initiators (free radical chain initiators). This
substance class includes, for example, oxygen, hydroperoxides,
peroxides and azo compounds, such as cumene hydroperoxide, t-butyl
hydroperoxide, dilauroyl peroxide, dibenzoyl peroxide,
bis(2-ethylhexyl) peroxydicarbonate, t-butyl perpivalate, t-butyl
permaleate, t-butyl perbenzoate, dicumyl peroxide, t-butyl cumyl
peroxide, di(t-butyl) peroxide,
2,2'-azobis(2-methylpropanonitrile),
2,2'-azobis(2-methylbutyronitrile). The initiators are used
individually or as a mixture of two or more substances in amounts
of from 0.01 to 20% by weight, preferably from 0.05 to 10% by
weight, based on the monomer mixture.
[0060] The high pressure bulk polymerization is carried out in
known high pressure reactors, for example autoclaves or tubular
reactors, batchwise or continuously, and tubular reactors have been
found to be particularly useful. Solvents such as aliphatic and/or
aromatic hydrocarbons or hydrocarbon mixtures, benzene or toluene
may be present in the reaction mixture. Preference is given to the
substantially solvent-free procedure. In a preferred embodiment of
the polymerization, the mixture of the monomers, the initiator and,
if used, the moderator, are fed to a tubular reactor via the
reactor entrance and also via one or more side branches. Preferred
moderators are, for example, hydrogen, saturated and unsaturated
hydrocarbons, for example propane or propene, aldehydes, for
example propionaldehyde, n-butyraldehyde or isobutyraldehyde,
ketones, for example acetone, methyl ethyl ketone, methyl isobutyl
ketone, cyclohexanone, and alcohols, for example butanol. The
comonomers and also the moderators may be metered into the reactor
either together with ethylene or else separately via sidestreams.
The monomer streams may have different compositions (EP-A-0 271 738
and EP-A-0 922 716).
[0061] Examples of suitable co- or terpolymers include:
[0062] ethylene-vinyl acetate copolymers having 10-40% by weight of
vinyl acetate and
[0063] 60-90% by weight of ethylene;
[0064] the ethylene-vinyl acetate-hexene terpolymers disclosed by
DE-A-34 43 475;
[0065] the ethylene-vinyl acetate-diisobutylene terpolymers
described in EP-B-0 203 554;
[0066] the mixture of an ethylene-vinyl acetate-diisobutylene
terpolymer and an ethylene/vinyl acetate copolymer disclosed by
EP-B-0 254 284;
[0067] the mixtures of an ethylene-vinyl acetate copolymer and an
ethylene-vinyl acetate-N-vinylpyrrolidone terpolymer disclosed in
EP-B-0 405 270;
[0068] the ethylene/vinyl acetate/isobutyl vinyl ether terpolymers
described in EP-B-0 463 518;
[0069] the ethylene/vinyl acetate/vinyl neononanoate or vinyl
neodecanoate terpolymers which, apart from ethylene, contain 10-35%
by weight of vinyl acetate and 1-25% by weight of the particular
neo compound, disclosed by EP-B-0 493 769;
[0070] the terpolymers of ethylene, a first vinyl ester having up
to 4 carbon atoms and a second vinyl ester which is derived from a
branched carboxylic acid having up to 7 carbon atoms or a branched
but nontertiary carboxylic acid having from 8 to 15 carbon atoms,
described in EP 0778875;
[0071] the terpolymers of ethylene, the vinyl ester of one or more
aliphatic C.sub.2- to C.sub.20-monocarboxylic acids and
4-methylpentene-1, described in DE-A-196 20 118;
[0072] the terpolymers of ethylene, the vinyl ester of one or more
aliphatic C.sub.2- to C.sub.20-monocarboxylic acids and
bicyclo[2.2.1]hept-2-ene, disclosed in DE-A-196 20 119;
[0073] the terpolymers of ethylene and at least one olefinically
unsaturated comonomer which contains one or more hydroxyl groups,
described in EP-A-0 926 168.
[0074] Preference is given to using mixtures of the same or
different ethylene copolymers. The polymers on which the mixtures
are based more preferably differ in at least one characteristic.
For example, they may contain different comonomers, different
comonomer contents, molecular weights and/or degrees of branching.
The mixing ratio of the different ethylene copolymers is preferably
between 20:1 and 1:20, preferably from 10:1 to 1:10, in particular
from 5:1 to 1:5.
[0075] The copolymers B are derived preferably from copolymers of
ethylenically unsaturated dicarboxylic acids and derivatives
thereof, such as lower esters and anhydrides. Preference is given
to maleic acid, fumaric acid, itaconic acid and especially maleic
anhydride. Particularly suitable comonomers are monoolefins having
from 10 to 20, in particular having from 12 to 18, carbon atoms.
These are preferably linear and the double bond is preferably
terminal, as, for example, in dodecene, tridecene, tetradecene,
pentadecene, hexadecene, heptadecene and octadecene. The ratio of
maleic anhydride to olefin or olefins in the polymer is preferably
in the range from 1:1.5 to 1.5:1, and is especially equimolar.
[0076] It is possible for minor amounts of up to 20 mol %,
preferably <10 mol %, especially <5 mol %, of further
comonomers also to be present which are copolymerizable with maleic
anhydride and the olefins mentioned, for example shorter- and
longer-chain olefins, allyl polyglycol ethers,
C.sub.1-C.sub.30-alkyl (meth)acrylates, styrenics or
C.sub.1-C.sub.20-alkyl vinyl ethers. Equally, minor amounts of
poly(isobutylenes) having molecular weights of up to 5000 g/mol are
used, and preference is given to highly reactive variants having a
high proportion of terminal vinylidene groups. These further
comonomers are not taken into account in the calculation of the
factor Q which is crucial for the effectiveness.
[0077] Alkyl polyglycol ethers correspond to the general formula
2
[0078] where
[0079] R.sup.1 is hydrogen or methyl,
[0080] R.sup.2 is hydrogen or C.sub.1-C.sub.4-alkyl,
[0081] m is a number from 1 to 100,
[0082] R.sup.3 is C.sub.1-C.sub.24-alkyl,
C.sub.5-C.sub.20-cycloalkyl, C.sub.6-C.sub.18-aryl or
--C(O)--R.sup.4,
[0083] R.sup.4 is C.sub.1-C.sub.40-alkyl,
C.sub.5-C.sub.10-cycloalkyl or C.sub.6-C.sub.18-aryl.
[0084] The inventive copolymers B) are prepared preferably at
temperatures between 50 and 220.degree. C., in particular from 100
to 190.degree. C., especially from 130 to 170.degree. C. The
preferred preparation process is solvent-free bulk polymerization,
but it is also possible to carry out the polymerization in the
presence of aprotic solvents such as benzene, toluene, xylene or of
higher-boiling aromatic, aliphatic or isoaliphatic solvents or
solvent mixtures such as kerosene or Solvent Naphtha. Particular
preference is given to polymerizing in a small amount of
moderating, aliphatic or isoaliphatic solvents. The proportion of
solvent in the polymerization mixture is generally between 10 and
90% by weight, preferably between 35 and 60% by weight. In the
solution polymerization, the reaction temperature may be adjusted
particularly simply by the boiling point of the solvent or by
working under reduced or elevated pressure.
[0085] The average molecular mass of the inventive copolymers B is
generally between 1200 and 200 000 g/mol, in particular between
2000 and 100 000 g/mol, measured by means of gel permeation
chromatography (GPC) against polystyrene standards in THF.
Inventive copolymers B have to be oil-soluble in dosages relevant
in practice, i.e. they have to dissolve without residue at
50.degree. C. in the oil to be additized.
[0086] The reaction of the monomers is initiated by free
radical-forming initiators (free-radical chain starters). This
substance class includes, for example, oxygen, hydroperoxides and
peroxides, for example cumene hydroperoxide, t-butyl hydroperoxide,
dilauryl peroxide, dibenzoyl peroxide, bis(2-ethylhexyl)
peroxodicarbonate, t-butyl perpivalate, t-butyl permaleate, t-butyl
perbenzoate, dicumyl peroxide, t-butyl cumyl peroxide, di(t-butyl)
peroxide, and also azo compounds, for example
2,2'-azobis(2-methylpropanonitrile) or
2,2'-azobis(2-methylbutyronitrile)- . The initiators are used
individually or as a mixture of two or more substances in amounts
of from 0.01 to 20% by weight, preferably from 0.05 to 10% by
weight, based on the monomer mixture.
[0087] The copolymers may be prepared either by esterifying maleic
acid, fumaric acid and/or itaconic acid with the appropriate
alcohols and subsequently copolymerizing, or by copolymerizing
olefin or olefins with itaconic anhydride and/or maleic anhydride
and subsequently esterifying. Preference is given to carrying out a
copolymerization with anhydrides and esterifying the resulting
copolymer after the preparation.
[0088] In both cases, the esterification is effected, for example,
by reacting with from 0.8 to 2.5 mol of alcohol per mole of
anhydride, preferably with from 1.0 to 2.0 mol of alcohol per mole
of anhydride, at from 50 to 300.degree. C. When approx. 1 mol of
alcohol is used per mole of anhydride, monoesters are formed. Here,
preference is given to esterification temperatures of from approx.
70 to 120.degree. C. When larger amounts of alcohol are used,
preferably 2 mol of alcohol per mole of anhydride, diesters are
formed at 100-300.degree. C., preferably 120-250.degree. C. The
water of reaction may be distilled off by means of an inert gas
stream or removed by means of azeotropic distillation in the
presence of an organic solvent. To this end, preferably 20-80%, in
particular 30-70%, especially 35-55% by weight of at least one
organic solvent is used. Here, copolymers having acid numbers of
30-70 mg KOH/g, preferably of 40-60 mg KOH/g, are regarded as
monoesters. Copolymers having acid numbers of less than 40 mg,
especially less than 30 mg KOH/g, are regarded as diesters.
Particular preference is given to monoesters.
[0089] Suitable alcohols are in particular linear, but they may
also contain minor amounts, for example up to 30% by weight,
preferably up to 20% by weight and especially up to 10% by weight,
of branched (in the 1- or 2-position) alcohols. Either shorter- or
longer-chain alcohols may be used, but their proportion is
preferably below 20 mol % and especially below 10 mol %, for
example between 1 and 5 mol %, based on the total amount of the
alcohols used. In the calculation of the Q factor, these shorter-
and longer-chain alcohols, where present, are not taken into
account, since they do not contribute to the effectiveness of the
additives.
[0090] Particularly preferred alcohols are octanol, decanol,
undecanol, dodecanol, tridecanol, tetradecanol, pentadecanol and
hexadecanol.
[0091] The use of mixtures of different olefins in the
polymerization and mixtures of different alcohols in the
esterification allows the effectiveness to be further adapted to
specific fatty acid ester compositions.
[0092] In a preferred embodiment, mixtures of the copolymers B
according to the invention are used, with the proviso that the
average of the Q values of the mixing components in turn assumes
values of from 21.0 to 28.0, preferably values from 22.0 to 27.0
and especially values from 23.0 to 26.0.
[0093] The mixing ratio of the additives A and B according to the
invention is (in parts by weight) from 20:1 to 1:20, preferably
from 10:1 to 1:10, in particular from 5:1 to 1:2.
[0094] The additives according to the invention are added to oils
in amounts of from 0.001 to 5% by weight, preferably from 0.005 to
1% by weight and especially from 0.01 to 0.5% by weight. They may
be used as such or else dissolved or dispersed in solvents, for
example aliphatic and/or aromatic hydrocarbons or hydrocarbon
mixtures, for example toluene, xylene, ethylbenzene, decane,
pentadecane, petroleum fractions, kerosene, naphtha, diesel,
heating oil, isoparaffins or commercial solvent mixtures such as
Solvent Naphtha, .RTM.Shellsol AB, .RTM.Solvesso 150, .RTM.Solvesso
200, .RTM.Exxsol, .RTM.Isopar and .RTM.Shellsol D types. They are
preferably dissolved in fuel oil of animal or vegetable origin
based on fatty acid alkyl esters. The additives according to the
invention preferably comprise 1-80%, especially 10-70%, in
particular 25-60%, of solvent.
[0095] In a preferred embodiment, the fuel oil F2, which is
frequently also referred to as biodiesel or biofuel, is a fatty
acid alkyl ester composed of fatty acids having from 12 to 24
carbon atoms and alcohols having from 1 to 4 carbon atoms.
Typically, a relatively large portion of the fatty acids contains
one, two or three double bonds.
[0096] Examples of oils F2 which are derived from animal or
vegetable material and can be used in accordance with the invention
are rapeseed oil, coriander oil, soya oil, cottonseed oil,
sunflower oil, castor oil, olive oil, peanut oil, maize oil, almond
oil, palmseed oil, coconut oil, mustardseed oil, bovine tallow,
bone oil, fish oils and used cooking oils. Further examples include
oils which are derived from wheat, jute, sesame, shea tree nut,
arachis oil and linseed oil. The fatty acid alkyl esters also
referred to as biodiesel can be derived from these oils by
processes disclosed by the prior art. Preference is given to
rapeseed oil, which is a mixture of fatty acids partially
esterified with glycerol, since it is obtainable in large amounts
and is obtainable in a simple manner by extractive pressing of
rapeseeds. In addition, preference is given to the likewise widely
available oils of sunflowers and soya, and also to their mixtures
with rapeseed oil.
[0097] Particularly suitable biofuels F2) are lower alkyl esters of
fatty acids. These include, for example, commercially available
mixtures of the ethyl, propyl, butyl and in particular methyl
esters of fatty acids having from 14 to 22 carbon atoms, for
example of lauric acid, myristic acid, palmitic acid, palmitolic
acid, stearic acid, oleic acid, elaidic acid, petroselic acid,
ricinolic acid, elaeostearic acid, linolic acid, linolenic acid,
eicosanoic acid, gadoleic acid, docosanoic acid or erucic acid,
each of which preferably has an iodine number of from 50 to 150, in
particular from 90 to 125. Mixtures having particularly
advantageous properties are those which comprise mainly, i.e.
comprise at least 50% by weight, of methyl esters of fatty acids
having from 16 to 22 carbon atoms, and 1, 2 or 3 double bonds. The
preferred lower alkyl esters of fatty acids are the methyl esters
of oleic acid, linoleic acid, linolenic acid and erucic acid.
[0098] Commercial mixtures of the type mentioned are obtained, for
example, by hydrolyzing and esterifying, or by transesterifying,
animal and vegetable fats and oils with lower aliphatic alcohols.
Equally suitable as starting materials are used cooking oils. To
prepare lower alkyl esters of fatty acids, it is advantageous to
start from fats and oils having a high iodine number, for example
sunflower oil, rapeseed oil, coriander oil, castor oil, soya oil,
cottonseed oil, peanut oil or bovine tallow. Preference is given to
lower alkyl esters of fatty acids based on a novel type of rapeseed
oil, more than 80% by weight of whose fatty acid component is
derived from unsaturated fatty acids having 18 carbon atoms.
[0099] A biofuel is therefore an oil which is obtained from
vegetable or animal material or both or a derivative thereof which
can be used as a fuel and in particular as a diesel or heating oil.
Although many of the above oils can be used as biofuels, preference
is given to vegetable oil derivatives, and particularly preferred
biofuels are alkyl ester derivatives of rapeseed oil, cottonseed
oil, soya oil, sunflower oil, olive oil or palm oil, and very
particular preference is given to rapeseed oil methyl ester,
sunflower oil methyl ester and soya oil methyl ester. Particularly
preferred as a biofuel or as a component in biofuel are
additionally also used fatty esters, for example used fatty acid
methyl ester.
[0100] Suitable mineral oil components F1 are in particular middle
distillates which are obtained by distilling crude oil and boil in
the range from 120 to 450.degree. C., for example kerosene, jet
fuel, diesel and heating oil. Preference is given to using those
middle distillates which contain 0.05% by weight of sulfur and
less, more preferably less than 350 ppm of sulfur, in particular
less than 200 ppm of sulfur and in special cases less than 50 ppm
of sulfur, for example less than 10 ppm of sulfur. These are
generally those middle distillates which have been subjected to
refining under hydrogenating conditions, and therefore contain only
small proportions of polyaromatic and polar compounds. They are
preferably those middle distillates which have 95% distillation
points below 370.degree. C., in particular 350.degree. C. and in
special cases below 330.degree. C. Synthetic fuels, as obtainable,
for example, by the Fischer-Tropsch process, are also suitable as
middle distillates.
[0101] The additive can be added to the oil to be additized in
accordance with prior art processes. When more than one additive
component or coadditive component is to be used, such components
can be introduced into the oil together or separately in any
desired combination and sequence.
[0102] The inventive additives allow the CFPP value of mixtures of
biodiesel and mineral oils to be improved much more efficiently
than using the known prior art additives. The inventive additives
are particularly advantageous in oil mixtures whose mineral oil
component F1) has a boiling range between the 20% and the 90%
distillation point of less than 120.degree. C., in particular of
less than 110.degree. C. and especially of less than 100.degree. C.
In addition, they are particularly advantageous in oil mixtures
whose mineral oil component F1) has a cloud point of below
-4.degree. C., in particular from -6.degree. C. to -20.degree. C.,
for example from -8.degree. C. to -20.degree. C., as required for
use in winter in particular. Equally, the pour point of the
inventive mixtures is reduced by the addition of the inventive
additives. The inventive additives are particularly advantageous in
oil mixtures which contain more than 11% by volume of biofuel F2,
preferably more than 12% by volume of biofuel F2 and especially
more than 15% by volume of biofuel F2, for example from 15 to 35%
by volume of biofuel F2. The inventive additives are additionally
particularly advantageous in problematic oils whose biofuel
component F2 contains a high proportion of esters of saturated
fatty acids of more than 4%, in particular of more than 5% and
especially having from 7 to 25%, for example having from 8 to 20%,
as present, for example, in oils from sunflowers and soya. Such
biofuels preferably have a cloud point of above -5.degree. C. and
especially above -3.degree. C. Oil mixtures F) in which the
inventive additives exhibit particularly advantageous action
preferably have cloud points of above -9.degree. C. and especially
of above -6.degree. C. It is thus also possible using the inventive
additives to adjust oil mixtures comprising rapeseed oil methyl
ester and sunflower and/or soya oil fatty acid methyl ester to CFPP
values of -22.degree. C. and below.
[0103] To prepare additive packages for specific solutions to
problems, the inventive additives can also be used together with
one or more oil-soluble coadditives which alone improve the cold
flow properties of crude oils, lubricant oils or fuel oils.
Examples of such coadditives are polar compounds which differ from
the inventive polymers B and bring about paraffin dispersion
(paraffin dispersants), alkylphenol condensates, esters and ethers
of polyoxyalkylene compounds, olefin copolymers, and also
oil-soluble amphiphiles.
[0104] For instance, the inventive additives may be used in a
mixture with paraffin dispersants to further reduce the
sedimentation under cold conditions of precipitated paraffins and
fatty acid esters. Paraffin dispersants reduce the size of the
paraffin and fatty acid ester crystals and have the effect that the
paraffin particles do not separate but remain dispersed colloidally
with a distinctly reduced tendency to sedimentation. Useful
paraffin dispersants have been found to be both low molecular
weight and polymeric oil-soluble compounds having ionic or polar
groups, for example amine salts and/or amides. Particularly
preferred paraffin dispersants comprise reaction products of
secondary fatty amines having from 20 to 44 carbon atoms, in
particular dicocoamine, ditallow fat amine, distearylamine and
dibehenylamine with carboxylic acids and derivatives thereof.
Particularly useful paraffin dispersants have been found to be
those obtained by reacting aliphatic or aromatic amines, preferably
long-chain aliphatic amines, with aliphatic or aromatic mono-, di-,
tri- or tetracarboxylic acids or their anhydrides (cf. U.S. Pat.
No. 4,211,534). Equally suitable paraffin dispersants are amides
and ammonium salts of aminoalkylenepolycarboxylic acids such as
nitrilotriacetic acid or ethylenediaminetetraacetic acid with
secondary amines (cf. EP 0 398 101). Other paraffin dispersants are
copolymers of maleic anhydride and .alpha.,.beta.-unsaturated
compounds which may optionally be reacted with primary
monoalkylamines and/or aliphatic alcohols (cf. EP 0 154 177) and
the reaction products of alkenyl-spiro-bislactones with amines (cf.
EP 0 413 279 B1) and, according to EP 0 606 055 A2, reaction
products of terpolymers based on .alpha.,.beta.-unsaturated
dicarboxylic anhydrides, .alpha.,.beta.-unsaturated compounds and
polyoxyalkylene ethers of lower unsaturated alcohols.
[0105] Alkylphenol-aldehyde resins are described, for example, in
Rompp Chemie Lexikon, 9th edition, Thieme Verlag 1988-92, volume 4,
p. 3351ff. In the alkylphenol-aldehyde resins which can be used in
the inventive additives, the alkyl radicals of the o- or
p-alkylphenol may be the same or different and have 1-50,
preferably 1-20, in particular 4-12, carbon atoms; they are
preferably n-, iso- and tert-butyl, n- and isopentyl, n- and
isohexyl, n- and isooctyl, n- and isononyl, n- and isodecyl, n- and
isododecyl and octadecyl. The aliphatic aldehyde in the
alkylphenol-aldehyde resin preferably has 1-4 carbon atoms.
Particularly preferred aldehydes are formaldehyde, acetaldehyde and
butyraldehyde, in particular formaldehyde. The molecular weight of
the alkylphenol-aldehyde resins is 400-10 000 g/mol, preferably
400-5000 g/mol. A prerequisite is that the resins are
oil-soluble.
[0106] In a preferred embodiment of the invention, these
alkylphenol-formaldehyde resins are those which contain oligo- or
polymers having a repeating structural unit of the formula 3
[0107] where R.sup.5 is C.sub.1-C.sub.50-alkyl or -alkenyl and n is
a number from 2 to 100. R.sup.5 is preferably
C.sub.4-C.sub.20-alkyl or -alkenyl and in particular
C.sub.6-C.sub.16-alkyl or -alkenyl. n is preferably a number from 4
to 50 and especially a number from 5 to 25.
[0108] Further suitable flow improvers are polyoxyalkylene
compounds, for example esters, ethers and ether/esters which bear
at least one alkyl radical having from 12 to 30 carbon atoms. When
the alkyl groups stem from an acid, the rest stems from a
polyhydric alcohol; when the alkyl radicals come from a fatty
alcohol, the rest of the compound stems from a polyacid.
[0109] Suitable polyols are polyethylene glycols, polypropylene
glycols, polybutylene glycols and their copolymers having a
molecular weight of from approx. 100 to approx. 5000, preferably
from 200 to 2000. Also suitable are alkoxylates of polyols, for
example glycerol, trimethylolpropane, pentaerythritol, neopentyl
glycol, and also the oligomers obtainable therefrom by condensation
and having from 2 to 10 monomer units, for example polyglycerol.
Preferred alkoxylates are those having from 1 to 100 mol, in
particular from 5 to 50 mol, of ethylene oxide, propylene oxide
and/or butylene oxide per mole of polyol. Particular preference is
given to esters.
[0110] Fatty acids having from 12 to 26 carbon atoms are preferably
used for reaction with the polyols to form the ester additives,
although preference is given to using C.sub.18 to C.sub.24 fatty
acids, especially stearic acid and behenic acid. The esters can
also be prepared by esterification of polyoxyalkylated alcohols.
Preference is given to fully esterified polyoxyalkylated polyols
having molecular weights of from 150 to 2000, preferably from 200
to 1500. PEG-600 dibehenate and glycerol-ethylene glycol
tribehenate are particularly suitable.
[0111] Olefin polymers suitable as a constituent of the inventive
additive may be derived directly from monoethylenically unsaturated
monomers or be prepared indirectly by hydrogenating polymers which
are derived from polyunsaturated monomers such as isoprene or
butadiene. In addition to ethylene, preferred copolymers contain
structural units which are derived from .alpha.-olefins having from
3 to 24 carbon atoms and molecular weights of up to 120 000.
Preferred .alpha.-olefins are propylene, butene, isobutene,
n-hexene, isohexene, n-octene, isooctene, n-decene, isodecene. The
comonomer content of olefins is preferably between 15 and 50 mol %,
more preferably between 20 and 35 mol % and especially between 30
and 45 mol %. These copolymers may also contain small amounts, for
example up to 10 mol %, of further comonomers, for example
nonterminal olefins or nonconjugated olefins. Preference is given
to ethylene-propylene copolymers. The olefin copolymers may be
prepared by known methods, for example by means of Ziegler or
metallocene catalysts.
[0112] Further suitable olefin copolymers are block copolymers
which contain blocks of olefinically unsaturated aromatic monomers
A and blocks of hydrogenated polyolefins B. Particularly suitable
block copolymers have the structure (AB).sub.nA and (AB).sub.m
where n is a number between 1 and 10 and m is a number between 2
and 10.
[0113] The mixing ratio (in parts by weight) of the inventive
additives with paraffin dispersants, comb polymers, alkylphenol
condensates, polyoxyalkylene derivatives and olefin copolymers
respectively is in each case from 1:10 to 20:1, preferably from 1:1
to 10:1, for example from 1:1 to 4:1.
[0114] The additives may be used alone or else together with other
additives, for example with other pour point depressants or
dewaxing assistants, with antioxidants, cetane number improvers,
dehazers, deemulsifiers, detergents, dispersants, antifoams, dyes,
corrosion inhibitors, conductivity improvers, sludge inhibitors,
odorants and/or additives for lowering the cloud point.
EXAMPLES
[0115] Characterization of the Test Oils:
[0116] The CFPP value is determined to EN 116 and the cloud point
to ISO 3015. Both properties are determined in .degree. C.
1TABLE 1 Characterization of the biofuels used (F2) Oil No. CP CFPP
E1 Rapeseed oil methyl ester -2.3 -14.degree. C. E2 80% rapeseed
oil methyl ester + 20% -1.6 -10.degree. C. sunflower oil methyl
ester E3 90% rapeseed oil methyl ester + 10% -2.0 -8.degree. C.
soya oil methyl ester
[0117]
2TABLE 2 Carbon chain distribution of the fatty acid methyl esters
used to prepare the test oils (main constituents; area % by GC):
C.sub.16 C.sub.16' C.sub.18 C.sub.18' C.sub.18'' C.sub.18'''
C.sub.20 C.sub.20' C.sub.22 .SIGMA. saturated RME 4.5 0.5 1.7 61.6
18.4 8.7 0.7 1.5 0.4 7.3 SFME 6.0 0.1 3.8 28.7 58.7 0.1 0.3 0.3 0.7
10.8 SoyaME 10.4 0.1 4.1 24.8 51.3 6.9 0.5 0.4 0.4 15.4 RME =
Rapeseed oil methyl ester; SFME = Sunflower oil methyl ester;
SoyaME = Soya oil methyl ester
[0118]
3TABLE 3 Characterization of the mineral oils used (F1) D1 D2 D3
Initial boiling point 193.degree. C. 181.degree. C. 200.degree. C.
20% distillation 230.degree. C. 235.degree. C. 247.degree. C. 90%
distillation 332.degree. C. 344.degree. C. 339.degree. C. 95%
distillation 348.degree. C. 361.degree. C. 358.degree. C. (90 -
20)% distillation 102.degree. C. 109.degree. C. 92.degree. C. Cloud
point -6.0.degree. C. -8.2.degree. C. -4.7.degree. C. CFPP
-8.degree. C. -12.degree. C. -9.degree. C. Sulfur content 20 ppm 32
ppm 9 ppm
[0119] The following additives were used:
[0120] Ethylene Copolymers A
[0121] The ethylene copolymers used are commercial products having
the characteristics specified in Table 4. The products were used as
65% dilutions in kerosene.
4TABLE 4 Characterization of the ethylene copolymers used (A)
Example Comonomer(s) V140 CH.sub.3/100 CH.sub.2 A1 13.6 mol % of
vinyl acetate 130 mPas 3.7 A2 13.7 mol % of vinyl acetate and 105
mPas 5.3 1.4 mol % of vinyl neodecanoate A3 i) 14.0 mol % of vinyl
acetate 97 mPas 4.7 and 1.6 mol % of vinyl neodecanoate and ii)
12.9 mol % of vinyl acetate 145 mPas 5.4 in a i):ii) ratio of
6:1
[0122] Comb Polymers B
[0123] The polymerization of maleic anhydride (MA) with
.alpha.-olefins is effected in a relatively high-boiling aromatic
hydrocarbon mixture at 160.degree. C. in the presence of a mixture
of equal parts of tert-butyl peroxybenzoate and tert-butyl
peroxy-2-ethylhexanoate as a free-radical chain starter. Table 5
lists various copolymers by way of example and the molar
proportions of the monomers used to prepare them, and also the
chain length and the molar amount (based on MA) of the alcohol used
for derivatization and the factor Q calculated therefrom.
[0124] The esterifications are effected in the presence of Solvent
Naphtha (from 40 to 50% by weight) at from 90 to 100.degree. C. to
give the monoester and at from 160 to 180.degree. C. with
azeotropic separation of the water of reaction to give the diester.
The degree of esterification is inversely proportional to the acid
number.
5TABLE 5 Characterization of the comb polymers used (B) Acid number
Example Comonomers Alcohol Q [mg KOH/g] B1
MA-co-C12/14-.alpha.-olefin C10 21.0 14.0 (1:0.5:0.5) B2
MA-co-C12/14-.alpha.-olefin C12 23.0 51.1 (1:0.5:0.5) B3
MA-co-C14/16-.alpha.-olefin C10 23.0 8.5 (1:0.5:0.5) B4
MA-co-C14/16-.alpha.-olefin C12 25.0 48.2 (1:0.5:0.5) B5
MA-co-C14/16-.alpha.-olefin C14 27.0 51.0 (1:0.5:0.5) B6
MA-co-C14/16-.alpha.-olefin 85% C12 25.6 49.9 (1:0.5:0.5) 15% C16
B7 MA-co-C16-.alpha.-olefin (1:1) C12 26.0 12.3 B8
MA-co-C16-.alpha.-olefin (1:1) C10 24.0 47.9 B9
MA-co-C14/16-.alpha.-olefin- C12 25.0 45.8 co-allyl methyl
polyglycol (1:0.45:0.45:0.1) B10 (C) MA-co-C10-.alpha.-olefin (1:1)
C12 20.0 48.8 B11 (C) MA-co-C14/16-.alpha.-olefin C16 29.0 16.5
(1:0.5:0.5) B12 (C) Fumarate-vinyl acetate C14 n.a. 0.4 n.a. = not
applicable (C) = comparative example
[0125] Further Flow Improvers
[0126] The further flow improvers used C are commercial products
having the characteristics specified in Table 6. The products were
used as 50% dilutions in Solvent Naphtha.
6TABLE 6 Characterization of the further flow improvers used C3
Reaction product of a copolymer composed of C.sub.14/C.sub.16
olefin and maleic anhydride with 2 equivalents of secondary tallow
fat amine per maleic anhydride unit C4 Reaction product of phthalic
anhydride with 2 equivalents of di(hydrogenated tallow fat amine)
to give an amide ammonium salt C5 Nonylphenol resin prepared by
condensation of a mixture of dodecylphenol with formaldehyde, Mw
2000 g/mol C6 Mixture of 2 parts of C3 and 1 part of C5 C7 Mixture
of equal parts of C4 and C5
[0127] Effectiveness of the Additives
[0128] The CFPP value (to EN 116, in .degree. C.) of different
biofuels as per the above table was determined after addition of
1200 ppm, 1500 ppm and 2000 ppm of additive mixture. Percentages
are based on parts by weight in the particular mixtures. The
results reproduced in Tables 5 to 7 show that the comb polymers
having the inventive factor Q achieve outstanding CFPP reductions
even at low dosages and offer additional potential at higher
dosages.
7TABLE 7 CFPP testing in a mixture of 75% by volume of test oil D1
and 25% by volume of test oil E1 (CP = -5.2.degree. C.; CFPP =
-9.degree. C.) CFPP after addition of flow improver Flow Comb 50
100 150 200 Ex. improver polymer/coadditive ppm ppm ppm ppm 1 A2
150 ppm B1 -15 -17 -19 -21 2 A2 150 ppm B2 -14 -18 -20 -22 3 A2 150
ppm B3 -18 -19 -19 -21 4 A2 150 ppm B4 -19 -21 -22 -23 5 A2 150 ppm
B5 -20 -21 -21 -21 6 A1 150 ppm B6 -20 -20 -22 -23 7 A1 100 ppm B7
-19 -20 -20 -22 8 A1 100 ppm B8 -19 -19 -20 -21 9 A1 100 ppm B9 -21
-20 -22 -23 10 A2 75 ppm B4 -19 -21 -23 -26 75 ppm A4 11 (C) A2 150
ppm B10 -12 -14 -17 -19 12 (C) A2 150 ppm B11 -7 -11 -16 -18 13 (C)
A2 150 ppm B12 -10 -11 -15 -20 14 (C) A2 -- -11 -16 -17 -19
[0129]
8TABLE 8 CFPP testing in a mixture of 70% by volume of test oil D2
and 30% by volume of test oil E3 (CP = -5.8.degree. C.; CFPP =
-12.degree. C.) Ethylene Comb CFPP Ex. copolymer polymer Coadditive
100 ppm 150 ppm 200 ppm 300 ppm 15 80% A3 20% B1 150 ppm C6 -20 -20
-21 -24 16 80% A3 20% B2 150 ppm C6 -20 -22 -25 -24 17 80% A3 20%
B3 150 ppm C6 -20 -20 -24 -25 18 80% A3 20% B4 150 ppm C6 -20 -21
-23 -26 19 75% A3 25% B5 150 ppm C6 -19 -20 -20 -26 20 85% A1 15%
B6 150 ppm C6 -20 -22 -24 -27 21 80% A1 20% B9 150 ppm C7 -20 -22
-25 -27 22 (C) 80% A3 20% B10 150 ppm C6 -19 -20 -19 -20 23 (C) 80%
A3 20% B11 150 ppm C6 -9 -14 -18 -19 24 (C) 80% A1 20% B12 150 ppm
C7 -15 -16 -18 -22 25 (C) 100% A1 -- 150 ppm C6 -18 -19 -20 -22
[0130] In this test series, in each case a constant amount of
coadditive and the specified amount of a mixture of ethylene
copolymer and comb polymer were added to the oil.
9TABLE 9 CFPP testing in a mixture of 80% by volume of test oil D3
and 20% by volume of test oil E2 (CP = -3.3.degree. C.; CFPP =
-10.degree. C.) CFPP Ethylene Comb 100 200 Ex. copolymer polymer
ppm ppm 250 ppm 300 ppm 26 80% A3 20% B1 -17 -20 -25 -26 27 80% A3
20% B2 -21 -24 -23 -26 28 80% A3 20% B3 -21 -23 -25 -27 29 80% A3
20% B4 -20 -23 -26 -29 30 80% A3 20% B5 -16 -20 -26 -26 31 75% A1
25% B6 -20 -23 -26 -29 32 75% A1 25% B9 -21 -24 -25 -28 33 (C) 80%
A3 20% B10 -17 -19 -22 -23 34 (C) 80% A3 20% B11 -10 -16 -17 -21 35
(C) 80% A1 20% B12 -15 -17 -19 -21 36 (C) 100% A1 -- -11 -20 -22
-22
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