U.S. patent application number 10/168404 was filed with the patent office on 2003-03-06 for polyacrylate esters, their preparation and use as a low-temperature flow-improver in middle distillate oils.
Invention is credited to Handa, Sheetal, Hodgson, Philip Kenneth Gordon.
Application Number | 20030041508 10/168404 |
Document ID | / |
Family ID | 10867006 |
Filed Date | 2003-03-06 |
United States Patent
Application |
20030041508 |
Kind Code |
A1 |
Handa, Sheetal ; et
al. |
March 6, 2003 |
Polyacrylate esters, their preparation and use as a low-temperature
flow-improver in middle distillate oils
Abstract
A polymer having structural units derived from an ester (1) of
an aliphatic carboxylic acid with an aliphatic alcohol, wherein
either the acid or the alcohol is ethylenically unsaturated and the
other of the acid or alcohol has a medium length chain group of 440
carbon atoms; said polymer having a molecular weight of less than
30,000.
Inventors: |
Handa, Sheetal; (Middlesex,
GB) ; Hodgson, Philip Kenneth Gordon; (Oxford,
GB) |
Correspondence
Address: |
Nixon & Vanderhye
8th Floor
1100 North Glebe Road
Arlington
VA
22201-4714
US
|
Family ID: |
10867006 |
Appl. No.: |
10/168404 |
Filed: |
August 28, 2002 |
PCT Filed: |
December 14, 2000 |
PCT NO: |
PCT/GB00/04796 |
Current U.S.
Class: |
44/397 |
Current CPC
Class: |
C08F 20/12 20130101;
C10L 1/1963 20130101; C10L 1/146 20130101; C08F 8/14 20130101; C10L
1/1973 20130101; C08F 8/14 20130101 |
Class at
Publication: |
44/397 |
International
Class: |
C10L 001/18 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 23, 1999 |
GB |
9930596.3 |
Claims
1. A polymer having structural units derived from an ester (1) of
an aliphatic carboxylic acid with an aliphatic alcohol, wherein
either the acid or the alcohol is ethylenically unsaturated and the
other of the acid or alcohol has a medium length chain group of
4-40 carbon atoms; said polymer having a molecular weight of less
than 30,000.
2. A process for the production of the polymer of claim 1, said
process comprising transesterification of a) at least one polymer
of an ester of an aliphatic carboxylic acid and an aliphatic
alcohol, wherein either said acid or said alcohol is ethylenically
unsaturated and the other of said acid or alcohol has a short chain
aliphatic group of 1-4 carbon atoms, with b) an aliphatic alcohol
or carboxylic acid having an aliphatic group of 4-40 carbon
atoms.
3. A process as claimed in claim 2, wherein said at least one
polymer of an ester of an aliphatic carboxylic acid and an
aliphatic alcohol is a polyacrylate.
4. A process as claimed in claim 3, wherein said polyacrylate is
polymethacrylate.
5. A process as claimed in claim 3 or 4, wherein the polyacrylate
employed has a molecular weight of 1000 to 3000 prior to
transesterification.
6. A process as claimed in any one of claims 2 to 5, wherein said
a) at least one polymer of an ester of an aliphatic carboxylic acid
and an aliphatic alcohol is transesterified with an aliphatic
alcohol having 6-16 carbons.
7. A polymer obtainable by the process of any one of claims 2 to
6.
8. A polymer as claimed in claim 7, which 60 to 63% by weight of
units derived from polymethacrylate and 37 to 40% of units derived
from a C12 to C16 alcohol.
9. A method of reducing wax formation and/or deposition in a
wax-containing middle distillate oil, said method comprising mixing
a polymer as claimed in claim 7 or 8 with said oil.
10. A method as claimed in claim 9, wherein the middle distillate
oil selected from the group consisting of kerosene, jet fuel,
diesel fuel, heating oil, visbroken gas oil, light cycle oil,
vacuum gas oil, light fuel oil and fuel oil.
11. A mixture comprising a middle distillate oil, a conventional
flow improver and a polymer as claimed in claim 7 or 8.
12. A mixture as claimed in claim 11, wherein said conventional
flow improver comprises ethyl vinyl acetate.
13. A mixture as claimed in claim 11 or 12, wherein the amount of
polymer present in said mixture is 2-10,000 ppm.
14. A mixture as claimed in any one of claims 11 to 13, wherein the
amount of conventional flow improver present is 10-10,000 ppm.
15. Use of a polymer as claimed in any one of claims 7 to 8, for
reducing at least one of the cloud point, CFPP and pour point of a
middle distillate oil.
16. Use of a polymer as claimed in any one of claims 7 to 8, for
reducing at least one of the cloud point, CFPP and pour point of a
mixture comprising a middle distillate oil and a conventional flow
improver.
17. Use as claimed in claim 16, wherein said conventional flow
improver comprises ethyl vinyl acetate.
Description
[0001] The present invention relates to polymers, especially ester
polymers, and to their preparation and use, particularly in diesel
fuels.
[0002] Diesel fuels are middle distillates, generally boiling
within the range of 170 to 390.degree. C. Such fuels comprise
hydrocarbons of varying types and molecular weights. Typically, 5
to 30% of the fuel consists of paraffinic hydrocarbons. Paraffinic
hydrocarbons tend to have limited solubility. Thus, when the fuel
is cooled, the less soluble, higher molecular weight paraffins tend
to come out of solution as waxy crystals. The temperature at which
this occurs is known as the cloud point of the fuel.
[0003] The waxy crystals formed at the cloud point have a strong
affinity for each other and readily interlock to form larger
crystal agglomerates. Thus, if the fuel is cooled further, more wax
will come out of solution until there is sufficient to form an
interlocking structure. Such structures may impede or prevent the
flow of fuel through, for example, fuel lines and filters, causing
operating difficulties in diesel fuel systems, particularly, during
the winter, when ambient temperatures are low.
[0004] We have now developed a polymer which may be added to middle
distillate oils to reduce the tendency for wax to deposit from such
oils.
[0005] According to the present invention, there is provided a
polymer having structural units derived from an ester (1) of an
aliphatic carboxylic acid with all aliphatic alcohol, wherein
either the acid or the alcohol is ethylenically unsaturated and the
other of the acid or alcohol has a medium length chain group of
4-40 carbon atoms; said polymer having a molecular weight of less
than 30,000.
[0006] The medium chain length group is preferably of 4 to 30
carbon atoms, more preferably, 6 to 25 carbon atoms, even more
preferably, 10 to 22 carbon atoms, preferably 6-15, more
preferably, 9-14 carbons, for example, 12 carbons.
[0007] Preferably, the molecular weight of the polymer is less than
25,000, for example, less than 20,000, preferably, less than 15,000
and more preferably, less than 10,000. In fact, the M.sub.w of the
polymer may be between 80 and 8,000; preferably, between 700 and
5000. In a preferred embodiment, the molecular weight is between
1800 and 3500.
[0008] Preferably also, the molecular weight distribution (Mw/Mn)
is 2-20, for example, 2-6.
[0009] The polymer may be such that at least 10%, for example, at
least 30%, for example, 35 to 45% of the aliphatic groups have said
medium length chain group of 4 to 40 carbon atoms.
[0010] Ester (1) may be derived from an ethylenically unsaturated
carboxylic acid, and a medium length chain alcohol. The unsaturated
group of the ethylenically unsaturated carboxylic acid may be
alpha, beta or gamma to the carboxylic group. The ethylenically
unsaturated carboxylic acid may contain 3 to 15, for example, 3 to
10 carbon atoms, and is especially an aliphatic alpha ethylenically
unsaturated carboxylic acid of formula CH.sub.2.dbd.CRCO.sub.2H,
wherein R is hydrogen or an alkyl group of 1-3 carbons, for
example, methyl, ethyl or propyl. Acrylic acids, and in particular,
methacrylic acids are preferred. The acid may also be a mono, di or
tricarboxylic acid. Suitable diacids include fumaric, maleic and
crotonic acids.
[0011] The medium length alcohol is preferably linear, but may be
branched. The alcohol contains 4-40 carbon atoms, preferably, 4 to
30, more preferably, 6 to 25 carbon atoms, even more preferably, 10
to 22 carbon atoms. Suitable alcohols may contain 8, 10, 12, 14,
16, 18, 20 or 22 carbon atoms. Thus, suitable alcohols include
octanol, decanol, dodecanol, tetradecanol, hexadecanol,
octadecanol, eicosanol, docosanol and nafol. Branched alcohols such
as, for example, 2-methyl dodecyl alcohol are also suitable. The
alcohol may be natural or synthesised, for example, by oxo or ALFOL
processes.
[0012] The alcohols employed may be substantially pure, but are
preferably mixtures of alcohols. Examples of such mixtures include
natural lauryl alcohols and mixtures of alkanols of even carbon
number, with one carbon number predominating with decreasing
proportions of alkanols of lower and higher carbon number, as in
e.g. a Gaussian distribution. Such mixtures may contain at least
50%, for example, at least 80 or 90% (by mole) of one alkanol.
Examples of such mixtures are commercially produced lauryl alcohol
with a majority of a 12 carbon alkanol and smaller amounts of 8, 10
and 14 carbon alkanols. Commercial mixtures of at least two of, for
example, 8, 10, 12, 14, 16, 18, 20 or 22 carbon alcohols may be
used.
[0013] The medium length chain aliphatic alcohol may also be
employed as a mixture of alcohols with a bimodal distribution of
the carbon number content, e.g. with at least 25% moles of each of
2 alcohols, especially alcohols different in at least 1, or at
least 3 carbons, such as 1-6 e.g. 2 or especially 3-6 e.g. 4 or 6
carbons. Examples of such mixtures are 8 and 12, or 10 and 14 or 8
and 14 carbon alkanols.
[0014] In a preferred embodiment, ester (1) is an acrylate of an
alcohol selected from the group consisting of: 1-octanol,
1-decanol, 1-dodecanol, 1-tetradecanol, 1-hexadecanol,
1-octadecaol, 1-eicosanol, and 1-docosanol. Preferably, no more
than two alcohols are selected from said group. Where two alcohols
are selected, they preferably have carbon numbers which differ by
two.
[0015] Ester (1) may also be derived from an ethylenically
unsaturated alcohol and a medium length chain carboxylic acid. The
unsaturated group of the ethylenically unsaturated alcohol may be
alpha, beta or gamma to the alcohol group. The ethylenically
unsaturated alcohol preferably contains 2 to 6 carbon atoms. It may
be an allyl alcohol, a methallyl alcohol, or a vinyl alcohol. The
alcohol may be linear, as in for example, CH.sub.2.dbd.CHOH.
Alternatively, the alcohol may be branched, for example, as in
methyl vinyl alcohol.
[0016] The medium length carboxylic acid is preferably linear, but
may be branched. The acid is preferably saturated and may contain 4
to 40 carbons, for example, preferably, 4 to 30, more preferably, 6
to 25 carbon atoms, even more preferably, 10 to 22 carbon atoms.
Suitable acids may comprise 8, 10, 12, 14, 16, 18, 20, or 22 carbon
atoms Examples of suitable acid are n-octanoic, n-decanoic,
n-undecanoic, n-dodecanoic, n-tridecanoic, n-tetradecanoic
acids.
[0017] The acids may be substantially pure, but are preferably
mixtures of acids, for example, as in lauric acid or mixtures of
acids of even carbon number with one carbon number predominating
with decreasing proportions of acids of lower and higher carbon
numbers, as in e.g. a Gaussian distribution. Such mixtures may
contain at least 50%, for example, at least 80 or 90% (by mole) of
one alkanoic acid and smaller amount(s) of other alkanoic acid(s).
Examples of such mixtures are commercial lauric acid consisting
predominantly of acids having 12 carbon atoms. Small amounts of
acids comprising 10 and 14 carbon atoms are also present.
[0018] The acid may also be used as a mixture of acids with a
bimodal distribution of the carbon number content.
[0019] In addition to structural units derived from ester (1), the
polymer may also comprise structural units derived from an ester
(2). Ester (2) is different to ester (1), but falls within the same
definition as ester (1). Thus, ester (2) is an ester of an
aliphatic carboxylic acid with an aliphatic alcohol, wherein either
the acid or the alcohol is ethylenically unsaturated and the other
of the acid or alcohol has a medium length chain group of 4-40
carbon atoms.
[0020] Where ester (1) is derived from an ethylenically unsaturated
carboxylic acid, and a medium length chain alcohol, ester (2) is
also derived from an ethylenically unsaturated carboxylic acid, and
a medium length chain alcohol. Where ester (1) is derived from an
ethylenically unsaturated alcohol, and a medium length chain
carboxylic acid, ester (2) is also derived from an ethyleneically
unsaturated alcohol, and a medium length chain carboxylic acid.
[0021] In addition to structural units derived from ester (1), and
optionally, ester (2), the polymer of the present invention may
also comprise structural units derived from an ester (3). Ester (3)
is an ester of an aliphatic carboxylic acid and an aliphatic
alcohol, wherein either the acid or the alcohol is ethylenically
unsaturated and the other of the acid or alcohol has a short chain
aliphatic group of 1-4 carbon atoms. Where present, units derived
from ester (3) may form 10 to 60 ml %, preferably, 20 to 40 mol %
of the resulting polymer.
[0022] Where ester (1) is derived from an ethylenically unsaturated
carboxylic acid, and a medium length chain alcohol, ester (3) is
derived from an ethyleneically unsaturated carboxylic acid and an
aliphatic alcohol of 1 to 4 carbon atoms. Suitable alcohols include
methanol, ethanol. propanol and butanol. Methanol and t-butanol are
preferred
[0023] Where ester (1) is derived from an ethyleneically
unsaturated alcohol, and a medium length chain carboxylic acid,
ester (3) is derived from an ethylenically unsaturated alcohol and
a carboxylic acid of 1 to 4 carbon atoms. Suitable acids include
formic acid, acetic acid, propaionic acid and buytyric acid. Acetic
acid and propionic acid are preferred.
[0024] The polymers of the invention may also contain structural
units from other unsaturated monomers e.g. ones monomers containing
at least one N and/or S atom or O atom in an ether linkage.
[0025] The polymers of the present invention may be obtained by
direct polymerisation of ester (1), optionally, with ester (2)
and/or (3). For example, for polymers comprising structural units
derived from esters (1), and (2) and/or (3), the constituent ester
monomers may be co-polymerised together directly.
[0026] The polymerisation may be performed in a conventional manner
with or without a diluent. Where a diluent is required, a
hydrocarbon diluent, such as hexane, heptane, or a higher boiling
hydrocarbon oil may be employed.
[0027] The polymerisation may be carried out at a temperature of
25-120.degree. C., such as 60-100.degree. C. Optionally, a free
radical catalyst, such as a peroxide or an azo catalyst may be
employed. Suitable free radical catalysts include benzoyl peroxide.
A suitable azo catalyst is azobis isobutyronitrile.
[0028] The polymerisation is usually performed under inert
conditions, for example, under nitrogen or argon. The
polymerisation time may be 0.5-40 hr, preferably 5-25 hr, at a
reaction temperature of 60-100.degree. C. At the end of the
polymerisation, the reaction product may be purified by evaporation
under vacuum to remove unreacted monomer, and/or precipitation of
the product with methanol from a liquid aromatic or aliphatic
hydrocarbon solution of the product.
[0029] As an alternative to polymerisation, the polymers may also
be produced by transesterification. Thus, according to a second
aspect of the present invention, there is provided a process for
production the production of a polymer comprising the
transesterification of at least one polymer of the ester (3) with
an aliphatic alcohol or carboxylic acid having an aliphatic group
of 4-40 carbon atoms.
[0030] Preferably, the alcohol or carboxylic acid has 4 to 30
carbon atoms, more preferably, 6 to 25 carbon atoms, even more
preferably, 10 to 22 carbon atoms, preferably 6-16, and most
preferably, 9-14 carbons, for example, 12 carbon atoms. Most
preferably, an aliphatic alcohol is employed.
[0031] In one embodiment, a polyacrylate is transesterified with an
alcohol having 4 to 40 carbon atoms. Preferably, the polyacrylate
has a molecular weight of 1000 to 3000, more preferably, 1500 to
2500, for example, about 2000-2100. A suitable polyacrylate is
polymethylacrylate. Most preferably, the polymethacrylate employed
has a molecular weight of 1000 to 3000, more preferably, 1500 to
2500, for example, about 2000-2100.
[0032] The transesterified product may comprise 15 to 85% by
weight, preferably, 55 to 75% by weight, more preferably, 60 to 70%
by weight, for example, 60 to 65% by weight of units derived from
the ester (3) polymer. The transesterified product may comprise 15
to 85% by weight, more preferably, 30 to 40% by weight, most
preferably, 35 to 40% by weight of units derived from the alcohol
or carboxylic acid. In one embodiment of the invention, the
transesterified product comprises 60 to 63% by weight of units
derived from the polymethacrylate and 37 to 40% of units derived
from the alcohol or carboxylic acid. In a most preferred
embodiment, the alcohol is a C12 or C16 alcohol.
[0033] The transesterification product of the invention may be
purified, or used as such. In the case of the latter, the
transesterification product may contain unreacted polymer and/or
unreacted alcohol or acid. The unreacted alcohol or acid may be
present in amount of 1-50%, for example, 10-50 % by weight, based
on the weight of polymer (3). The unreacted alcohol or acid may
optionally be removed.
[0034] The transesterification reaction may be performed at
50-150.degree. C., for example, 60-120.degree. C. The reaction time
may be 1-30 hours, preferably, 5-20 hours.
[0035] A catalyst may be used to catalyse the transesterification
reaction. Suitable catalysts include organic soluble strong acids
and basic catalysts. Suitable acids include aromatic sulphuric
acids, such as p-toluene sulphonic acid. Suitable basic catalysts
include metal alkoxides. Suitable metal alkoxides include
polyvalent metal alkoxides such as tetra methyl or tetra ethyl
titanate, and alkali metal alkoxides such as sodium methoxide or
ethoxide. Such alkoxides may be added as such or may be prepared in
situ. Amounts of the basic catalyst may be 0.05-5% e.g. 0.1-1% by
weight of the feed polymer.
[0036] The present invention also provides a method of reducing wax
formation and/or deposition in a wax-containing middle distillate
oil, said method comprising mixing a polymer of the present
invention with said oil.
[0037] Preferably, said oil is mixed with a polymer of the present
invention which is prepared using the transesterification process
described above.
[0038] The middle distillate oil employed is typically a petroleum
based oil obtainable from crude oil. Preferably, the middle
distillate oil is obtainable as a fraction distilling in the
lighter fuel oil (e.g. kerosene or jet fuel range) to the heavy
fuel oil range (eg heating oil). Middle distillates may comprise
atmospheric or vacuum distillates, cracked gas oil or blends of
straight run and thermally and/or catalytically cracked
distillates. Examples of suitable middle distillates include
kerosene, jet fuel, diesel fuel, heating oil, visbroken gas oil,
light cycle oil, vacuum gas oil, light fuel oil and fuel oil. The
boiling range or the middle distillate measured (according to
IP123/ASTM D86) is usually 100-500.degree. C. eg 140-400.degree. C.
Diesel oil eg for vehicles which may be for summer or especially
winter use, is preferred.
[0039] The middle distillate oil may comprise hydrocarbons which
may be primarily aliphatic or aromatic in nature. Preferably,
however, the oil comprises mixtures of aliphatic and aromatic
hydrocarbons. The hydrocarbon may contain 0.01 to 30%, for example,
0.1 to 5% by weight of wax.
[0040] In the absence of the polymers of the invention, the middle
distillate oil may have a cloud point value of at least -20.degree.
C., for example, -20 to 5.degree. C., more specifically, -15 to
0.degree. C. In certain embodiments, the middle distillate oil may
have a cloud point of -15 to -5.degree. C., for example, between -6
and -7.degree. C. The polymers of the present invention may reduce
the cloud point of the middle distillate oil by more than
0.2.degree. C., preferably, more than 0.5.degree. C., more
preferably, more than 1.degree. C., for example, between 0.2 and
3.degree. C.
[0041] In the absence of the polymers of the invention, the pour
point of the middle distillate oil may be 1-20.degree. C., for
example, 1-10.degree. C. lower than the WAT (Wax Appearance
Temperature) value. Thus, the pour point may be -30.degree. C. to
0.degree. C. e.g. -20.degree. C. to -5.degree. C. The polymers of
the invention may reduce the pour point value of the liquid
hydrocarbon by at least 3.degree. C. e.g. 3-21.degree. C. such as
6-15.degree. C.
[0042] In the absence of the polymers of the present invention, the
cold filter plugging point (CFPP) of the middle distillate oil may
be at least -20.degree. C., for example, 0 to -20.degree. C., more
specifically, -15 to -5.degree. C., for example, -10 to -5.degree.
C. The polymers of the present invention may reduce the CFPP of the
middle distillate oil by more than 0.5.degree. C., preferably, more
than 1.degree. C., more preferably, more than 2.degree. C., and
most preferably, more than 3.degree. C., for example, by 3 to
10.degree. C.
[0043] The middle distillate oil may also contain at least one
additive. Suitable additives include conventional flow improvers,
such as a polyoxyalkylene compounds, ethylene vinyl acetate (EVA)
copolymers, and nitrogenous compounds, preferably having at least
one long chain such as of 4-40 carbons, hydrocarbyl bonded directly
to nitrogen such as an amine salt or amide. Examples of suitable
polyoxyalkylene compounds include polyoxyethylene diester, diether
or ester/ether or mixtures thereof
[0044] Other suitable additives include detergents, anti foams,
ignition improvers, lubricity additives and/or corrosion
inhibitors. Mixtures of additives may be present in the middle
distillate oil.
[0045] The polymer of the present invention may be added to the
middle distillate oil, such that the final concentration of the
polymer in the oil is 2-10,000, preferably, 5-10,000 ppm, more
preferably, 10-8,000 ppm, even more preferably, 20-5000 ppm, yet
more preferably, 50-1000 ppm. For example, the final concentration
of the polymer in the oil may be 100 to 600 ppm, or more
specifically, 250 to 500 ppm based on the weight of oil.
[0046] The polymer of the invention may be added to the middle
distillate oil/middle distillate oil-containing mixture either
batchwise, continually or continuously. For example, the polymer
may be contacted with a moving liquid body of the oil, preferably,
by adding the polymer to a line containing flowing liquid oil,
upstream of a cooler location where wax deposition may occur in the
absence of said compound. If desired the polymers of the invention
may be added to a tank of the oil e.g. to inhibit deposition of
wax.
[0047] It is possible to add the polymer directly to the middle
distillate oil. Alternatively, the polymer may first be dissolved
in a liquid solvent, and the resulting solution added to the middle
distillate oil. Suitable solvents include hydrocarbon solvents such
as toluene and/or xylene. The resulting solution may also comprise
at least one of the aforementioned additives. The resulting
solution or concentrate is such that each of the polymer and
additive(s) is present in an amount of at least 1% e.g. at least 5%
(by weight).
[0048] It has been found that when the polymers of the present
invention are used in combination with certain additives, in
particular, conventional flow improvers such as EVA, the activity
of the additives is enhanced. Thus, according to yet another aspect
of the present invention, there is provided a mixture comprising a
middle distillate oil, a conventional flow improver and a polymer
of the present invention. This mixture may be prepared by adding
the polymer of the present invention to a mixture comprising a
middle distillate oil and a conventional flow improver, or adding a
conventional flow improver to a mixture comprising a middle
distillate oil and the polymer of the present invention.
Alternatively, the polymer of the present invention and the
conventional flow improver may be added simultaneously to a middle
distillate oil.
[0049] Suitable middle distillate oils, polymers of the present
invention and conventional flow improvers include those described
earlier in this specification. The preferred conventional flow
improver employed is EVA. The preferred polymer of the present
invention is one prepared by transesterification. Most preferably,
this transesterified polymer is prepared by the transesterification
of polymethacrylate and an alcohol. In one embodiment of the
invention, the transesterified product comprises 60 to 63% by
weight of units derived from the polymethacrylate and 37 to 40% of
units derived from a C12 or C 16 alcohol. The starting
polymethacrylate may have a molecular weight of 1500 to 3000,
preferably, 2000 to 2500, for example, about 2100.
[0050] The amount of polymer present in the mixture of the present
invention may be 2-10,000, preferably, 5-10,000 ppm, more
preferably, 10-8,000 ppm, even more preferably, 20-5000 ppm, and
yet more preferably, 50-1000 ppm. For example, the final
concentration of the polymer in the oil may be 100 to 600 ppm, or
more specifically, 250 to 500 ppm based on the weight of oil. The
amount of conventional flow improver present may be 10-10,000 ppm,
preferably, 20-5000 ppm, more preferably, 50-1000 ppm, even more
preferably, 100 to 600 ppm, for example, 250 to 500 ppm based on
the weight of oil. The mixture of the present invention may also
contain 5-2000 ppm e.g. 30-1000 ppm (on the same basis) of medium
chain alcohol, e.g. of 8-14 or 10-12 carbons, such as described for
use in the preparation of the ester polymer.
[0051] Yet another aspect of the present invention is the use of a
polymer as described above in a method for reducing at least one of
the cloud point, CFPP and pour point of a middle distillate
oil.
[0052] The present invention also provides the use of a polymer as
described above for enhancing the flow characteristics (such as
pour point, cloud point and/or cold filter plugging point (CFPP))
of a mixture comprising a middle distillate oil and a conventional
flow improver, such as EVA.
[0053] The invention is illustrated in the following Examples:
EXAMPLE 1
[0054] A stirred solution of poly(methyl acrylate), M.sub.w 2,100,
(5.05g) and tetradecanol (7.55g) in toluene (100 ml), was heated in
an oil bath at 130 C under Dean-Stark solvent removal conditions
for 8 hours. Toluene (10 ml) was removed each 0.5 hr period and an
equal amount of fresh toluene was replaced at that time.
[0055] After 1 hr sodium methoxide catalyst was added (47 mg).
Extra sodium methoxide (95 mg). was added after another hour (total
added =142 mg). The toluene solution of product, after cooling, was
used as such is a 27% w/w solution.
[0056] Proton NMR spectroscopy indicated that the
transesterification had proceeded to 77%, because of a 77:23 ratio
of signals from the ester alkyl hydrogens to ester methyl
hydrogens.
EXAMPLE 2
[0057] The procedure of Example 1 was followed with poly(methyl
acrylate), MW 2,100, (5.04 g) and 1-dodecanol (6.49 g) and 165 mg
of sodium methoxide was added in total. Proton NMR indicated a
degree of transesterification of 84%.
EXAMPLE 3
[0058] The procedure of Example 1 was followed with poly(methyl
acrylate), MW 2,100, (5.13 g) and Nafol 1618H (4.40 g). The sodium
methoxide catalyst (94.5 mg) was added after 1.5 hours. The
reaction was run for 10.5 hours. Proton NMR indicated a degree of
transesterification of 38%.
EXAMPLE 4
[0059] The procedure of Example 1 was followed with poly(methyl
acrylate), MW 2,100, (5.23 g) and 1-eicosanol (5.27 g). Xylene was
used as the solvent instead of toluene. The reaction was run for
14.5 hours. After 1.5 hours sodium methoxide catalyst was added
(0.118 g). Proton NMR indicated a degree of transesterification of
40%.
EXAMPLE 5
[0060] The procedure of Example 1 was followed with poly(methyl
acrylate), MW 2,100, (5.17 g) and 1-docosanol (5.71 g). Xylene was
used as the solvent instead of toluene. The reaction was run for
14.5 hours. After 1.5 hours sodium methoxide catalyst was added
(0.118 g). Proton NMR indicated a degree of transesterification of
42%.
EXAMPLE 6
[0061] The procedure of Example 1 was followed with poly(methyl
acrylate), MW 2,100, (3.08g) and 1-docosanol (6.66 g). Xylene was
used as the solvent instead of toluene. The reaction was run for 10
hours. After 1.25 hours sodium methoxide catalyst (47 mg) was
added. Additional sodium methoxide (71 mg) was added another 1.45
hours later. 1H NMR indicated a degree of transesterification of
83%. There was 6% of the initial 1-docosanol left unreacted.
EXAMPLE 7
[0062] A stirred solution of poly(methyl acrylate), MW 2,100, (5.09
g) and 1-dodecanol (3.21 g) in 100 ml of toluene was heated in an
oil bath to 130 C with water and methanol removal using 4A
molecular sieves for 9 hours.
[0063] After 2 hours sodium methoxide catalyst (0.1 18 g) was
added. The toluene solution of product, after cooling, was used as
such is a 15% w/w solution.
[0064] Proton NMR spectroscopy indicated that the
transesterification had proceeded to 37%, because of a 37:63 ratio
of signals from the ester alkyl hydrogens to ester methyl
hydrogens.
EXAMPLE 8
[0065] The procedure of Example 7 was followed with poly(methyl
acrylate), MW 2,100, (5.08 g) and 1-hexdecanol (4.30 g) and sodium
methoxide (142 mg). The reaction was run for 9 hours. Proton NMR
spectroscopy indicated a degree of transesterification of 40%.
EXAMPLE 9
[0066] The procedure of Example 7 was followed with poly(methyl
acrylate), MW 2,100, (5.08 g) and 1-octadecanol (4.80 g). The
reaction was run for 9 hours and 142 mg of sodium methoxide
catalyst was used in total. Proton NMR indicated a degree of
transesterification of 40%.
EXAMPLE 10
[0067] The procedure of Example 7 was followed with poly(methyl
acrylate), MV 2,100, (5.08g) and 1-tetradecanol (3.81 g). The
reaction was run for 8 hours. 1 hour into the reaction sodium
methoxide catalyst was added (47 mg). After another hour a second
portion of sodium methoxide catalyst (47 mg) was added. 1H NMR
indicated a degree of transesterification of 37%. The product was
present at 17% w/w in toluene.
EXAMPLE 11
[0068] The cloud point and CFPP of a middle distillate oil
(commercial ultra low sulphur diesel grade) having the
characteristics in Table 1 below were measured using IP 219/ASTM
D2500 and IP 309, respectively. The cloud point was found to be
-6.5.degree. C., and the CFPP, -9.degree. C.
[0069] The polymer produced in Example 7 was then added to the
middle distillate oil of Table 1, such that the amount of polymer
in the resulting mixture was 500 ppm. The cloud point and CFPP of
the resulting mixture were -7.5 and -17.degree. C.,
respectively.
[0070] It can be seen from this Example that the polymer of the
present invention can be used to improve the cloud point and CFPP
characteristics of a middle distillate oil.
1 TABLE 1 Density 0.84 kg/m.sup.3 Initial Boiling point 200.degree.
C. Final boiling Point 350.degree. C.
EXAMPLE 12
[0071] In this Example, the polymer produced in Example 7 and EVA
were added to the middle distillate of Table 1, such that the
resulting mixture contained 500 ppm of the polymer of Example 7 and
250 ppm of EVA. The CFPP of the resulting mixture was found to be
-27.degree. C.
[0072] It can be seen from this Example that when EVA and the
polymer of Example 7 are added to a middle distillate oil, the CFPP
of the middle distillate oil is decreased from -9.degree. C. to
-27.degree. C.
COMPARATIVE EXAMPLE A
[0073] EVA was added to a heating oil in the proportions described
in Table 2 below, and the CFPPs of the resulting mixtures were
measured. The heating oil employed had a density of 0.845
g/cm.sup.3, a cloud point of 0.4, an initial boiling point of
170.degree. C., and a final boiling point of 387.degree. C.
2TABLE 2 EVA/ppm 100 200 400 600 CFPP/.degree. C. -7 -9 -11 -11
EXAMPLE 13
[0074] In this Example, the polymer produced in Example 7 was added
to the mixtures of Comparative Example A, in an amount of 5% of the
amount of EVA already present in each of the respective mixtures.
The CFPPs of the resulting mixtures were measured (see Table
3).
3TABLE 3 EVA/ppm 100 200 400 600 Polymer of Ex. 7/ppm 5 10 20 30
CFPP/.degree. C. -16 -16 -18 -18
EXAMPLE 14
[0075] In this Example, a blend of heating oil, EVA (100 ppm) and
polymer of Example 7 (10 ppm) was prepared. The CFPP of the blend
was found to be -16.degree. C.
EXAMPLE 15
[0076] In this Example, a blend of heating oil, EVA (100 ppm) and
polymer of Example 7 (40 ppm) was prepared. The CFPP of the blend
was found to be -18.degree. C.
* * * * *