U.S. patent application number 11/803858 was filed with the patent office on 2007-11-22 for cold flow improvers for vegetable or animal fuel oils.
This patent application is currently assigned to Clariant International Ltd.. Invention is credited to Markus Kupetz, Waltraud Nagel, Bettina Siggelkow.
Application Number | 20070270318 11/803858 |
Document ID | / |
Family ID | 38324145 |
Filed Date | 2007-11-22 |
United States Patent
Application |
20070270318 |
Kind Code |
A1 |
Siggelkow; Bettina ; et
al. |
November 22, 2007 |
Cold flow improvers for vegetable or animal fuel oils
Abstract
The present invention relates to a fuel oil additive comprising
A) a copolymer of ethylene and from 18 to 35 mol % of at least one
acrylic ester or vinyl ester having a C.sub.1-C.sub.18-alkyl
radical and a degree of branching of less than 5 CH.sub.3/100
CH.sub.2 groups, and B) a comb polymer comprising structural units
formed from 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 amide and/or imide group, in which the
parameter Q Q = i w 1 i n 1 i + j w 2 j n 2 j ##EQU00001## in which
w.sub.1 is the molar proportion of the individual chain lengths n,
in the alkyl radicals of monomer 1, w.sub.2 is the molar proportion
of the individual chain lengths n.sub.2 in the alkyl radicals of
the amide and/or imide 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 amide and/or imide groups of monomer 2, i is the serial
variable for the chain lengths in the alkyl radicals of monomer 1,
and is the serial variable for the chain lengths in the alkyl
radicals of the amide and/or imide groups of monomer 2 assumes
values of from 23 to 27.
Inventors: |
Siggelkow; Bettina;
(Frankfurt am Main, DE) ; Nagel; Waltraud;
(Oberhausen, DE) ; Kupetz; Markus; (Dinslaken,
DE) |
Correspondence
Address: |
CLARIANT CORPORATION;INTELLECTUAL PROPERTY DEPARTMENT
4000 MONROE ROAD
CHARLOTTE
NC
28205
US
|
Assignee: |
Clariant International Ltd.
|
Family ID: |
38324145 |
Appl. No.: |
11/803858 |
Filed: |
May 16, 2007 |
Current U.S.
Class: |
508/467 ;
44/389 |
Current CPC
Class: |
C10L 10/14 20130101;
C10L 1/2364 20130101; C10L 1/146 20130101; C10L 1/1973
20130101 |
Class at
Publication: |
508/467 ;
44/389 |
International
Class: |
C10L 1/18 20060101
C10L001/18; C10M 145/16 20060101 C10M145/16 |
Foreign Application Data
Date |
Code |
Application Number |
May 16, 2006 |
DE |
10 2006 022 720.4 |
Claims
1. A fuel oil additive comprising A) a copolymer of ethylene and
from 18 to 35 mol % of at least one acrylic ester or vinyl ester
having a C.sub.1-C.sub.18-alkyl radical and a degree of branching
of less than 5 CH.sub.3/100 CH.sub.2 groups, and B) a comb polymer
comprising structural units formed from 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 C8-C.sub.16-alkyl radical bonded via an amide and/or imide
group, in which the parameter Q Q = i w 1 i n 1 i + j w 2 j n 2 j
##EQU00003## in which w.sub.1 is the molar proportion of the
individual chain lengths n, in the alkyl radicals of monomer 1,
w.sub.2 is the molar proportion of the individual chain lengths
n.sub.2 in the alkyl radicals of the amide and/or imide 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 amide and/or imide groups of monomer 2, i
is the serial variable for the chain lengths in the alkyl radicals
of monomer 1, and j is the serial variable for the chain lengths in
the alkyl radicals of the amide and/or imide groups of monomer 2
assumes values of from 23 to 27.
2. The fuel oil additive as claimed in claim 1, wherein Q assumes
values of from 24 to 26.
3. The fuel oil additive as claimed in claim 1, wherein constituent
A) comprises from 18.5 to 27 mol % of at least one vinyl ester.
4. The fuel oil additive of claim 1, wherein constituent A)
comprises from 0.5 to 10 mol % of olefins having from 3 to 10
carbon atoms.
5. The fuel oil additive of claim 1, wherein the degree of
branching of constituent A) is less than 4 CH.sub.3/100 CH.sub.2
groups, determined by means of .sup.1H NMR spectroscopy.
6. The fuel oil additive of claim 1, wherein the at least one
olefin which forms constituent B1) is an .alpha.-olefin.
7. The fuel oil additive of claim 1, wherein a molar ratio of
comonomer B1) to comonomer B2) in copolymer B) is between 1.5:1 and
1:1.5.
8. The fuel oil additive of claim 1, wherein copolymer B, as well
as comonomers B1) and B2), further comprises up to 20 mol % of a
further comonomer other than B1) and B2), selected from the group
consisting of an olefin having from 2 to 50 carbon atoms, an allyl
polyglycol ether, a C.sub.1-C.sub.30-alkyl (meth)acrylate a
vinylaromatic or a C.sub.1-C.sub.20-alkyl vinyl ether, and a
polyisobutene having molecular weights of up to 5000 g/mol.
9. The fuel oil additive of claim 1, wherein constituent A) has a
melt viscosity V.sub.140 of from 5 to 100 mPas.
10. The fuel oil additive of claim 1, wherein constituent A) has a
molecular weight of from 1000 to 10 000 g/mol.
11. The fuel oil additive of claim 1, in which constituent B) has a
molecular weight Mw of from 1200 to 200 000 g/mol.
12. A fuel oil composition comprising a fuel oil of vegetable or
animal origin and the fuel oil additive of claim 1.
13. The fuel oil composition as claimed in claim 12, wherein the
fuel oil further comprises a mixture of fatty acid esters of
C.sub.1- to C.sub.4-alcohols.
14. The fuel oil composition as claimed in claim 13, wherein the
fatty acid esters include stearic acid methyl ester and palmitic
acid methyl ester in a proportion of at least 7% by weight.
15. A process for improving the cold behavior of fuel oils of
vegetable or animal origin, said process comprising admixing a
portion of the fuel oil additive of claim 1 with said fuel oil.
Description
[0001] The present invention relates to an additive, to its use as
a cold flow improver for vegetable or animal fuel oils and to
correspondingly additized 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. 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, therefore 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, and generally correspond to the formula
##STR00001##
where R is an aliphatic radical which has from 10 to 25 carbon
atoms and may be saturated or unsaturated.
[0004] 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.
[0005] 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 lower alcohols such as methanol or ethanol.
[0006] A hindrance to the use of triglycerides and also fatty acid
esters of lower monohydric alcohols as a replacement for diesel
fuel, alone or in a mixture with diesel fuel, has been found to be
their flow behavior at low temperatures. The cause of this is the
high uniformity 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. It has hitherto
been impossible using the prior art additives to reliably attain 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 worsened when oils are used which
comprise relatively large amounts of saturated fatty acid esters,
as are present, for example, in sunflower oil methyl ester, used
oil methyl ester or soybean oil methyl ester.
[0007] EP-A-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).
[0008] EP-A-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:
[0009] (I) 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, [0010] (II)
polyoxyalkylene ester, ester/ether or a mixture thereof, [0011]
(III) ethylene/unsaturated ester copolymer, [0012] (IV) polar,
organic, nitrogen-containing paraffin crystal growth inhibitor,
[0013] (V) hydrocarbon polymer, [0014] (VI) sulfur-carboxyl
compounds and [0015] (VII) aromatic pour point depressant modified
with hydrocarbon radicals, with the proviso that the composition
does not comprise any 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.
[0016] EP-A-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 [0017] 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 [0018] b) cooling the nonadditized
long-chain fatty acid esters FAE to a temperature below the cold
filter plugging point and [0019] c) removing the resulting
precipitates (FAN).
[0020] DE-A-40 40 317 discloses mixtures of fatty acid lower alkyl
esters having improved cold stability comprising [0021] 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, [0022] 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 [0023] c)
from 0.1 to 2% by weight of at least one polymeric ester.
[0024] EP-A-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.
[0025] EP-A-0 153 177 discloses an additive concentrate which
comprises a combination of [0026] 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 [0027] II) another low
temperature flow improver for distillate fuel oils.
[0028] EP-A-1 491 614 discloses oils of vegetable or animal origin
and their blends with crude oil distillate fuel oils, which
comprise an ethylene-vinyl ester copolymer which contains at least
17 mol % of vinyl ester and has a degree of branching of 5 or more
alkyl branches per 100 methylene groups to improve their low
temperature properties.
[0029] With the known additives, it is often impossible to reliably
adjust fatty acid esters, especially those which comprise a total
of more than 7% by weight of palmitic acid methyl ester and stearic
acid methyl ester, to a CFPP of -10.degree. C. which is required
for use as winter diesel in Southern Central Europe and of
-20.degree. C. in Northern Central Europe, and of -22.degree. C.
and lower for specific applications. An additional problem with the
existing additives is a lack of cold transition stability of the
additized oils, i.e. the set CFPP value of the oils rises gradually
when the oil is stored for a prolonged period at varying
temperatures in the region of its cloud point or lower. Moreover,
especially oils having a high content of palmitic acid methyl ester
and stearic acid methyl ester exhibit a strong tendency to
sedimentation in the course of storage at low temperatures. It is
known from practice that sedimentation of the additized fatty acid
esters which occurs in laboratory experiments under cold
conditions, in spite of the CFPP being attained, can lead to filter
blockages in the engine and the fuel is thus not suitable for use
in transport.
[0030] It was therefore an object of the invention to provide
additives for improving the cold flow behavior of fatty acid esters
which are derived, for example, from rapeseed oil, used oil,
sunflower oil and/or soybean oil and which comprise, at least 7% by
weight of palmitic acid methyl ester and stearic acid methyl ester,
to set CFPP values of -10.degree. C. or -20.degree. C. or lower
which remain constant even in the course of prolonged storage of
the oil in the region of its cloud point and lower. Moreover, these
additives should contribute to preventing the sedimentation
tendency of these oils, such that, even after storage of the fatty
acid esters for several days, they remain homogeneous and
free-flowing and their CFPP does not change either.
[0031] It has now been found that, surprisingly, an additive
comprising ethylene copolymers and comb polymers is an outstanding
flow improver for such fatty acid esters.
[0032] The invention provides an additive comprising [0033] A) a
copolymer of ethylene and from 18 to 35 mol % of at least one
acrylic ester or vinyl ester having a C.sub.1-C.sub.18-alkyl
radical and a degree of branching of less than 5 CH.sub.3/100
CH.sub.2 groups, and [0034] B) a comb polymer comprising structural
units formed from [0035] 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 [0036] 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 amide and/or imide
group, [0037] in which the parameter Q
[0037] Q = i w 1 i n 1 i + j w 2 j n 2 j ##EQU00002##
in which [0038] w.sub.1 is the molar proportion of the individual
chain lengths n.sub.1 in the alkyl radicals of monomer 1, [0039]
w.sub.2 is the molar proportion of the individual chain lengths
n.sub.2 in the alkyl radicals of the amide and/or imide groups of
monomer 2, [0040] n.sub.1 are the individual chain lengths in the
alkyl radicals of monomer 1, [0041] n.sub.2 are the individual
chain lengths in the alkyl radicals of the amide and/or imide
groups of monomer 2, [0042] iis the serial variable for the chain
lengths in the alkyl radicals of monomer 1, and [0043] jis the
serial variable for the chain lengths in the alkyl radicals of the
amide and/or imide groups of monomer 2 [0044] assumes values of
from 23 to 27.
[0045] The invention further provides a fuel oil composition
comprising a fuel oil of animal or vegetable origin and the
above-defined additive.
[0046] The invention further provides for the use of the
above-defined additive for improving the cold flow properties of
fuel oils of animal or vegetable origin.
[0047] The invention further provides a process for improving the
cold flow properties of fuel oils of animal or vegetable origin by
adding the above-defined additive to fuel oils of animal or
vegetable origin.
[0048] In a preferred embodiment of the invention, Q assumes values
of from 24 to 26.
[0049] Chain length of olefins is understood here to mean the chain
length of the monomeric olefin minus the two olefinically bonded
carbon atoms. In olefins with nonterminal double bonds, for example
olefins with vinylidene moiety, the chain length is equal to the
total chain length of the olefin minus the two olefinically bonded
carbon atoms.
[0050] When the polymers formed from the olefins B1) and the
dicarboxamides/imides B2) rather than the monomeric olefins are
considered, the chain length is the length of the alkyl radicals
which--introduced into the polymer by the olefin--depart from the
polymer backbone.
[0051] Suitable ethylene copolymers A) are preferably those which
contain from 18 to 35 mol % of one or more vinyl esters and/or
(meth)acrylic esters and from 65 to 82% by weight of ethylene.
Particular preference is given to ethylene copolymers having from
18.5 to 27 mol % of at least one vinyl ester. Suitable vinyl esters
derive from fatty acids having linear or branched alkyl groups
having from 1 to 30 carbon atoms. Preferred ethylene copolymers
have a melt viscosity V.sub.140 of at least 5 mPas, preferably from
10 to 100 mPas, in particular from 20 to 60 mPas.
[0052] Examples of suitable vinyl esters are vinyl acetate, vinyl
propionate, vinyl butyrate, vinyl hexanoate, vinyl heptanoate,
vinyl octanoate, vinyl laurate and vinyl stearate, and 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 acid and methacrylic acid 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, hexyl (meth)acrylate, octyl (meth)acrylate,
2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, dodecyl
(meth)acrylate, tetradecyl (meth)acrylate, hexadecyl
(meth)acrylate, octadecyl (meth)acrylate. Also suitable are
mixtures of two, three, four or even more of these comonomers.
[0053] Further preferred copolymers contain, in addition to
ethylene and from 18 to 35 mol % of vinyl esters, also from 0.5 to
10 mol % of olefins having from 3 to 10 carbon atoms, for example
propene, butene, isobutylene, hexene, 4-methylpentene, octene,
diisobutylene and/or norbornene.
[0054] The copolymers A preferably have weight-average molecular
weights Mw, measured by means of gel permeation chromatography
(GPC) against polystyrene standards in THF of from 1000 to 10 000
g/mol, in particular from 1500 to 5000 g/mol. Their degrees of
branching determined by means of .sup.1H NMR spectroscopy (400 MHz
with CDCl.sub.3 as the solvent) are less than 5 CH.sub.3/100
CH.sub.2 groups, preferably less than 4 CH.sub.3/100 CH.sub.2
groups. The methyl groups stem from the short-chain and long-chain
branches, and not from copolymerized comonomers.
[0055] 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 250.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 to a
minimum, 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.
[0056] 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) peroxodicarbonate, 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.
[0057] The high-pressure bulk polymerization is carried out in
known high-pressure reactors, for example autoclaves or tubular
reactors, batchwise or continuously; 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, is 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).
[0058] Examples of suitable co- or terpolymers include:
ethylene-vinyl acetate copolymers having 10-40% by weight of vinyl
acetate and 60-90% by weight of ethylene;
[0059] the ethylene-vinyl acetate-hexene terpolymers known from
DE-A-34 43 475;
[0060] the ethylene-vinyl acetate-diisobutylene terpolymers
described in EP-A-0 203 554;
[0061] the mixture of an ethylene-vinyl acetate-diisobutylene
terpolymer and an ethylene/vinyl acetate copolymer known from
EP-A-0 254 284;
[0062] the mixtures of an ethylene-vinyl acetate copolymer and an
ethylene-vinyl acetate-N-vinylpyrrolidone terpolymer known from
EP-A-0 405 270;
[0063] the ethylene/vinyl acetate/isobutyl vinyl ether terpolymers
described in EP-A-0 463 518;
[0064] 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, known from EP-A-0 493 769;
[0065] 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-A-0 778 875;
[0066] 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-19620 118;
[0067] 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;
[0068] 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.
[0069] Preference is given to using mixtures of identical 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.
[0070] The copolymers B are derived from the amides and imides of
ethylenically unsaturated dicarboxylic acids. Preferred
dicarboxylic acids are maleic acid, fumaric acid and itaconic acid,
and especially maleic anhydride. Particularly suitable comonomers
are monoolefins B1 having from 10 to 20, in particular having from
12 to 18, carbon atoms.
[0071] These are preferably linear and the double bond is
preferably terminal, as, for example, in dodecene, tridecene,
tetradecene, pentadecene, hexadecene, heptadecene and octadecene.
The molar ratio of dicarboxamide/imide to olefin or olefins in the
polymer is preferably in the range from 1:1.5 to 1.5:1, and is
especially equimolar.
[0072] It is possible for copolymer B also to contain minor amounts
of up to 20 mol %, preferably <10 mol %, especially <5 mol %,
of further comonomers which are copolymerizable with ethylenically
unsaturated dicarboxamides/imides and the olefins mentioned, for
example olefins having from 2 to 50 carbon atoms, allyl polyglycol
ethers, C.sub.1-C.sub.30-alkyl (meth)acrylates, vinylaromatics 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, preference being 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
parameter Q which is critical for the effectiveness.
[0073] Allyl polyglycol ethers correspond to the general
formula
##STR00002##
where [0074] R.sup.1 is hydrogen or methyl, [0075] R.sup.2 is
hydrogen or C.sub.1-C.sub.4-alkyl, [0076] m is a number from 1 to
100, [0077] 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, [0078] 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.
[0079] The inventive copolymers B) are prepared preferably at
temperatures between 50 and 220.degree. C., in particular from 100
to 190.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 solvent 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.
[0080] The average molecular mass Mw 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 doses relevant in
practice, i.e. they have to dissolve without residue at 50.degree.
C. in the oil to be additized.
[0081] 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,
dilauroyl 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.
[0082] The copolymers B may be prepared either by reacting maleic
acid, fumaric acid and/or itaconic acid or their anhydrides with
the corresponding amine and subsequently copolymerizing, or by
copolymerizing olefin or olefins with at least one unsaturated
dicarboxylic acid or derivative thereof, for example itaconic
anhydride and/or maleic anhydride and subsequently reacting with
amines. Preference is given to carrying out a copolymerization with
anhydrides and converting the resulting copolymer to an amide
and/or an imide after the preparation.
[0083] In both cases, the reaction with amines is effected, for
example, by reacting with from 0.8 to 2.5 mol of amine per mole of
anhydride, preferably with from 1.0 to 2.0 mol of amine per mole of
anhydride, at from 50 to 300.degree. C. When approx. 1 mol of amine
is used per mole of anhydride, monoamides are formed preferentially
at reaction temperatures of from approx. 50 to 100.degree. C. and
additionally bear one carboxyl group per amide group. At higher
reaction temperatures of from approx. 100 to 250.degree. C., imides
are formed preferentially from primary amines with elimination of
water. When larger amounts of amine are used, preferably 2 mol of
amine per mole of anhydride, amide-ammonium salts are formed at
from approx. 50 to 200.degree. C. and diamides at higher
temperatures of, for example, 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
(diluted to 50% in solvent) having acid numbers of 30-70 mg KOH/g,
preferably of 40-60 mg KOH/g, are regarded as monoamides.
Corresponding copolymers having acid numbers of less than 40 mg,
especially less than 30 mg KOH/g, are regarded as diamides or
imides. Particular preference is given to monoamides and
diamides.
[0084] Suitable amines are primary and secondary amines having one
or two C.sub.8-C.sub.16-alkyl radicals. They may bear one, two or
three amino groups which are bonded via alkylene radicals having
two or three carbon atoms. Preference is given to monoamines. In
particular, they bear linear alkyl radicals, but 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 amines
(in the 1- or 2-position). Either shorter- or longer-chain amines
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 amines used.
[0085] Particularly preferred primary amines are octylamine,
2-ethylhexylamine, decylamine, undecylamine, dodecylamine,
n-tridecylamine, isotridecylamine, tetradecylamine,
pentadecylamine, hexadecylamine and mixtures thereof.
[0086] Preferred secondary amines are dioctylamine, dinonylamine,
didecylamine, didodecylamine, ditetradecylamine, dihexadecylamine,
and also amines having different alkyl chain lengths, for example
N-octyl-N-decylamine, N-decyl-N-dodecylamine,
N-decyl-N-tetradecylamine, N-decyl-N-hexadecylamine,
N-dodecyl-N-tetradecylamine, N-dodecyl-N-hexadecylamine,
N-tetradecyl-N-hexadecylamine. Also suitable in accordance with the
invention are secondary amines which, in addition to a
C.sub.8-C.sub.16-alkyl radical, bear shorter side chains having
from 1 to 5 carbon atoms, for example methyl or ethyl groups. In
the case of secondary amines, it is the average of the alkyl chain
lengths of from C.sub.8 to C.sub.16 that is taken into account as
the alkyl chain length n for the calculation of the parameter Q.
Neither shorter nor longer alkyl radicals, where present, are taken
into account in the calculation, since they do not contribute to
the effectiveness of the additives.
[0087] Particularly preferred copolymers B contain monoamides and
diamides of primary monoamines as monomer 2.
[0088] The use of mixtures of different olefins in the
polymerization and mixtures of different amines in the amidation or
imidation allows the effectiveness to be further adapted to
specific fatty acid ester compositions.
[0089] In a preferred embodiment, the additives, as well as
constituents A and B, may also comprise polymers and copolymers
based on C.sub.10-C.sub.24-alkyl acrylates or methacrylates
(constituent C). These poly(alkyl acrylates) and methacrylates have
molecular weights Mw of from 800 to 1 000 000 g/mol, and derive
preferably from caprylic alcohol, capric alcohol, undecyl alcohol,
lauryl alcohol, myristyl alcohol, cetyl alcohol, palmitoleyl
alcohol, stearyl alcohol or mixtures thereof, for example coconut
alcohol, palm alcohol, tallow fat alcohol or behenyl alcohol.
[0090] In a preferred embodiment, mixtures of different copolymers
B are used, the mean (weight average) of the parameter Q of the
mixture components assuming values of from 23 to 27 and preferably
values of from 24 to 26.
[0091] The mixing ratio of the inventive additive constituents A
and B is (in parts by weight) from 20:1 to 1:20, preferably from
10:1 to 1:10, in particular from 5:1 to 1:5. The proportion of
component C in the formulations composed of A, B and C may be up to
40% by weight; it is preferably less than 20% by weight, in
particular between 1 and 10% by weight, based on the total weight
of A, B and C.
[0092] The inventive additives 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 0.6% 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.Hydrosol
A 200 N, .RTM.Shellsol A 150 ND, .RTM.Caromax 20 LN, .RTM.Shellsol
AB, .RTM.Solvesso 150, .RTM.Solvesso 150 ND, .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 inventive additives
preferably comprise 1-80%, especially 10-70%, in particular 25-60%,
of solvent.
[0093] In a preferred embodiment, the fuel oil, which is frequently
also referred to as biodiesel or biofuel, comprises fatty acid
alkyl esters 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.
[0094] Examples of oils which are derived from animal or vegetable
material and in which the inventive additive can be used are
rapeseed oil, coriander oil, soya oil, cottonseed oil, sunflower
oil, castor oil, olive oil, peanut oil, maize oil, almond oil, palm
kernel 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 used oil, palm oil,
sunflowers and soya, and also to their mixtures with rapeseed
oil.
[0095] Particularly suitable biofuels 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, palmitoleic
acid, stearic acid, oleic acid, elaidic acid, petroselic acid,
ricinolic acid, elaeostearic acid, linoleic 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.
[0096] 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.
[0097] 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 firstly to vegetable oil derivatives, particularly
preferred biofuels being 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, palm oil methyl ester and soya oil
methyl ester. Owing to the high demand for biofuels, ever more
manufacturers are switching from fatty acid methyl esters to other
raw material sources with higher availability. Mention should be
made here particularly of used oil, which is used in the form of
used oil methyl ester as biodiesel alone or in a blend with other
fatty acid methyl esters, for example rapeseed oil methyl ester,
sunflower oil methyl ester, palm oil methyl ester and soybean oil
methyl ester. Mention should also be made of mixtures of rapeseed
oil methyl ester with soybean oil methyl ester or rapeseed oil
methyl ester with a mixture of soybean oil methyl ester and palm
oil methyl ester or a mixture of soybean oil methyl ester and palm
oil methyl ester.
[0098] The additive can be introduced to the oil to be additized by
processes known in the prior art. 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
combination.
[0099] The inventive additives allow the CFPP value of biodiesel to
be adjusted to values of -10.degree. C. and below -20.degree. C.
and in some cases to values of below -25.degree. C., as required
for marketing for use especially in winter. Equally, the pour point
of biodiesel is lowered by the addition of the inventive additives.
The inventive additives are particularly advantageous in
problematic oils which have a high proportion of esters of the
saturated fatty acids palmitic acid and stearic acid of more than
7% by weight, as present, for example, in fatty acid methyl. esters
obtained from used oil, sunflowers and soybean. It is thus also
possible with the inventive additives to adjust mixtures of
rapeseed oil methyl ester and/or used oil methyl ester and/or
sunflower oil methyl ester and/or soybean oil methyl ester to CFPP
values of -10.degree. C. or -20.degree. C. and lower. It is thus
also possible with the inventive additives to adjust used oil
methyl ester or sunflower oil methyl ester or soybean oil methyl
ester to CFPP values of -10.degree. C. or -20.degree. C. and lower.
In addition, the oils thus additized have a good cold transition
stability, i.e. the CFPP value remains constant even in the case of
storage under winter conditions, and do not tend to sediment at
constant low temperatures (e.g. -10.degree. C. or -22.degree.
C.).
[0100] To produce additive packages for specific solutions to
problems, the inventive additives may also be used together with
one or more oil-soluble coadditives which, even alone, improve the
cold flow properties of crude oils, lubricant oils or fuel oils.
Examples of such coadditives are polar compounds which bring about
paraffin dispersancy (paraffin dispersants) and oil-soluble
amphiphiles.
[0101] The inventive additives may be used in a mixture with
paraffin dispersants. Paraffin dispersants reduce the size of the
paraffin crystals and have the effect that the paraffin particles
do not settle out but rather remain dispersed in colloidal form
with significantly reduced sedimentation tendency. 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. Particular preferred paraffin
dispersants comprise reaction products of secondary fatty amines
having from 20 to 44 carbon atoms, in particular dicoconut amine;
ditallow fat amine, distearylamine and dibehenylamine with
carboxylic acids and their derivatives. Particularly useful
paraffin dispersants have been found to be those which are 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 as 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-A-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.
[0102] The mixing ratio (in parts by weight) of the inventive
additives with paraffin dispersants is from 1:10 to 20:1,
preferably from 1:1 to 10:1.
[0103] The oils treated with the inventive additive may also be
added to middle distillates obtained from crude oil. The mixtures
of biofuel and middle distillate thus obtained can in turn be
admixed with cold additives such as flow improvers or wax
dispersants, and also performance packages.
[0104] The mixing ratio between biofuel and middle distillates may
be between 1:99 and 99:1. Particular preference is given to mixing
ratios of biofuel:middle distillate =3:97 to 30:70.
[0105] Middle distillate refers in particular to those mineral oils
which are obtained by distilling crude oil and boil within 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. They
are generally those middle distillates which have been subjected to
refining under hydrogenating conditions, and which 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. Suitable middle
distillates are also synthetic fuels, as made available, for
example, by the Fischer-Tropsch process.
[0106] The additives may be used alone or else together with other
additives, for example with other pour point depressants or
dewaxing aids, with antioxidants, cetane number improvers,
dehazers, demulsifiers, detergents, dispersants, defoamers, dyes,
corrosion inhibitors, conductivity improvers, sludge inhibitors,
odorants and/or additives for lowering the cloud point.
EXAMPLES
TABLE-US-00001 [0107] TABLE 1 Characterization of the ethylene
copolymers used CH.sub.3/100 Content of Example Comonomer(s)
V.sub.140 CH.sub.2 vinyl ester A1 (C) Ethylene/VAC/ 110 mPas 4.2
13.3 mol % vinyl neodecanoate A2 Ethylene/VAC 52 mPas 4.0 20.2 mol
% A3 (C) Ethylene/VAC 154 mPas 3.0 16.7 mol % A4 (C) Ethylene/VAC
125 mPas 3.0 13.8 mol % VAC = vinyl acetate
[0108] The vinyl ester content was measured by means of pyrolysis
and subsequent titration.
[0109] The viscosity (V.sub.140) was measured with a Haake
Reostress 600 viscometer.
[0110] The degree of branching (CH.sub.3/100CH.sub.2) was measured
on a .sup.1H NMR unit at 400 MHz in CDCl.sub.3, and calculated by
means of integration of the individual signals.
TABLE-US-00002 TABLE 2 Characterization of the comb polymers used
Acid number Example Comonomers Amine Q [mg KOH/g] B1
MSA-co-C.sub.14/.sub.16-.alpha.-olefin C.sub.12 amine 25 2
(1:0.5:0.5) B2 MSA-co-C.sub.14/.sub.16-.alpha.-olefin C.sub.14
amine 25.0 57 (1:0.5:0.5)
TABLE-US-00003 TABLE 3 Acrylates C1 Poly(octadecyl acrylate), K
value 32 C2 Poly(behenyl acrylate), K value 18
TABLE-US-00004 TABLE 4 Characterization of the test oils Oil No.:
CFPP [.degree. C.] Composition E1 -16 RME E2 -13 RME/AME 90:10 E3
-11 RME/AME 80:20 E4 -12 RME/SoyaME 92:8 E5 -12 RME/SoyaME 80:20 E6
-9 RME/SoyaME 60:40 E7 -8 RME/PME 85:15 SoyaME = soya methyl ester
RME = rapeseed oil methyl ester PME = palm oil methyl ester AME =
used oil methyl ester
TABLE-US-00005 TABLE 5 Methyl ester distribution of the test oils
E1 E2 E3 E4 E5 E6 E7 C16:0 4.27 6.81 5.58 5.22 5.8 7.14 11.18 C18:0
0.92 2.35 2.35 1.01 1.94 2.25 2.25 C18:1 59.48 54.55 54.88 55.94
53.08 43.93 52.87 C18:2 29.56 20.79 21.84 23.48 25.27 32.04 19.43
C18:3 1.58 9.58 9.58 9.59 8.31 7.47 8.81 C20:1/2/3 1.48 1.49 1.61
1.43 1.33 1.09 1.23 C20:0 0.63 0.66 0.67 0.64 0.65 0.6 0.63 C22:0
0.23 0.39 0.44 0.39 0.39 0.39 0.34
[0111] In the tables which follow, the mixing ratio according to
weight of the additives A, B and C is A:B=4:1, or, when C is
present in the mixtures, A:B:C=4:1:0.2. The total amount of
additive is evident from the top row of the table.
TABLE-US-00006 TABLE 6 CFPP testing in test oil E1 Comb Ethylene
1200 1500 Ex. polymer copolymer Polyacrylate 1000 ppm ppm ppm 1 B1
A2 -- -23 -26 -28 2 (C) B1 A1 -- -18 -20 -22
TABLE-US-00007 TABLE 7 CFPP testing in test oil E2 Comb Ethylene
1200 1500 Ex. polymer copolymer Polyacrylate 1000 ppm ppm ppm 3 (C)
B1 A1 -- -13 -13 -16 4 B1 A2 C1 -14 -17 -22 5 B1 A2 -- -13 -18 -22
6 (C) B2 A3 -- -13 -14 -15
TABLE-US-00008 TABLE 8 CFPP testing in test oil E3 Comb Ethylene
Poly- 800 1000 1500 Ex. polymer copolymer acrylate ppm ppm ppm 7
(C) B1 A1 -- -11 -18 -22 8 B1 A2 -- -20 -23 -24 9 B1 A2 C1 -19 -22
-25 10 (C) B1 A3 -- -11 -17 -16
TABLE-US-00009 TABLE 9 CFPP testing in test oil E4 Comb Ethylene
Poly- 1200 1500 2000 Ex. polymer copolymer acrylate ppm ppm ppm 11
(C) B1 A1 -- -17 -20 -23 12 B1 A2 -- -20 -22 -22 13 B1 A2 C1 -20
-23 -22 14 (C) B1 A3 -- -16 -18 -18 15 (C) B2 A3 -- -15 -17 -18
TABLE-US-00010 TABLE 10 CFPP testing in test oil E5 Comb Ethylene
Poly- 1500 2000 Ex. polymer copolymer acrylate ppm ppm 16 (C) B1 A1
-- -19 -21 17 B1 A2 -- -20 -23 18 (C) B1 A4 -- -17 -19
TABLE-US-00011 TABLE 11 CFPP testing in test oil E6 Ethylene Ex.
Comb polymer copolymer Polyacrylate 2000 ppm 21(C) B1 A1 -- -18 23
B1 A2 -- -21
TABLE-US-00012 TABLE 12 CFPP testing in test oil E7 Comb Ethylene
Ex. polymer copolymer Polyacrylate 4000 5000 24 (C) B1 A1 -- -11
-14 26 B1 A2 -- -14 -16
* * * * *