U.S. patent application number 12/810753 was filed with the patent office on 2010-11-04 for bifunctional additives for liquid hydrocarbons obtained by grafting starting with copolymers of ethylene and/or propylene and vinyl ester.
This patent application is currently assigned to TOTAL RAFFINAGE MARKETING. Invention is credited to Nelly Dolmazon, Valerie Heroguez, Geraldine Papin, Frederic Tort.
Application Number | 20100275508 12/810753 |
Document ID | / |
Family ID | 39719188 |
Filed Date | 2010-11-04 |
United States Patent
Application |
20100275508 |
Kind Code |
A1 |
Dolmazon; Nelly ; et
al. |
November 4, 2010 |
BIFUNCTIONAL ADDITIVES FOR LIQUID HYDROCARBONS OBTAINED BY GRAFTING
STARTING WITH COPOLYMERS OF ETHYLENE AND/OR PROPYLENE AND VINYL
ESTER
Abstract
The disclosure relates to the synthesis and the use of
copolymers based on ethylene and/or of propylene and of vinyl
ester(s) modified by grafting, effective for improving both the
resistance to cold and the lubricity of liquid hydrocarbons in
particular the middle distillates originating from the distillation
of petroleum and crude oils, in particular those with a low sulphur
content and relates to a copolymer including: a) units derived from
ethylene of formula A --(CH.sub.2--CH.sub.2).sub.n1-- and/or
propylene of formula A' --((CH.sub.3)CH.sub.2--CH.sub.2).sub.n2
with n1+n2=n ranging from 98 to 643, preferably ranging from 124 to
515; n1 being advantageously equal to n; b) units of formula B:
--(CH.sub.2--CHOOCR.sub.1).sub.m-x-- in which R.sub.1 represents a
C.sub.1-C.sub.15 linear or branched alkyl group preferably methyl,
propyl, and/or a C5 to C15 branched alkyl group, in which the
branching is situated at any point of the alkyl radical, preferably
in position 2 or 3 of the alkyl chain; preferably chosen from the
preferred C5-C15 vinyl comonomers, preferably chosen from the
pivalate, isopentanoate, isohexanoate, isononanoate, isodecanoate
and/or isotridecanoate, and advantageously 2-ethyl hexanoate,
neoalkanoates, in particular neononanoate, neodecanoate and/or
neoundecanoate; with m ranging from 2 to 105, preferably ranging
from 16 to 71 and x ranging from 0.2 to 105, preferably ranging
from 1.6 to 71; c) units of formula C: --(CH.sub.2--CHOH).sub.x1--
in which x1 ranges from 0 to 0.30x, preferably x1=0; d) units of
formula D: --(CH.sub.2--CHOOCR.sub.2).sub.x2-- in which x2 ranges
from 0.70x to x, preferably x2=x, and R.sub.2 represents a
C.sub.8-C.sub.24 saturated or unsaturated, linear or branched,
alkyl group, preferably C.sub.14-C.sub.20 or also C.sub.14 to
C.sub.18 with x=x.sub.1+x.sub.2.
Inventors: |
Dolmazon; Nelly; (Serezin,
FR) ; Papin; Geraldine; (Lyon, FR) ; Tort;
Frederic; (Brignais, FR) ; Heroguez; Valerie;
(Merignac, FR) |
Correspondence
Address: |
HARNESS, DICKEY & PIERCE, P.L.C.
P.O. BOX 828
BLOOMFIELD HILLS
MI
48303
US
|
Assignee: |
TOTAL RAFFINAGE MARKETING
PUTEAUX
FR
|
Family ID: |
39719188 |
Appl. No.: |
12/810753 |
Filed: |
December 23, 2008 |
PCT Filed: |
December 23, 2008 |
PCT NO: |
PCT/FR08/01816 |
371 Date: |
June 25, 2010 |
Current U.S.
Class: |
44/393 |
Current CPC
Class: |
C08F 8/14 20130101; C08F
2810/50 20130101; C10L 1/1817 20130101; C10N 2030/06 20130101; C10N
2030/02 20130101; C08F 210/06 20130101; C10M 145/12 20130101; C10L
1/1973 20130101; C08F 210/16 20130101; C10L 10/08 20130101; C10M
2209/082 20130101; C08F 210/02 20130101; C10L 1/1641 20130101; C10L
1/143 20130101; C08F 2800/20 20130101; C08F 8/12 20130101; C10L
10/14 20130101; C10N 2060/00 20130101; C10N 2030/08 20130101; C08F
8/12 20130101; C08F 210/02 20130101; C08F 8/14 20130101; C08F
210/02 20130101; C08F 210/02 20130101; C08F 218/08 20130101; C08F
216/06 20130101; C08F 210/02 20130101; C08F 218/08 20130101; C08F
210/06 20130101; C08F 210/08 20130101; C08F 216/06 20130101; C08F
210/16 20130101; C08F 218/08 20130101; C08F 216/06 20130101; C10M
2209/082 20130101; C10M 2209/062 20130101; C10M 2205/022
20130101 |
Class at
Publication: |
44/393 |
International
Class: |
C10L 1/196 20060101
C10L001/196 |
Foreign Application Data
Date |
Code |
Application Number |
Dec 26, 2007 |
FR |
07 09093 |
Claims
1. A use as bifunctional lubricity and resistance to cold additive
for liquid hydrocarbon compositions of at least one copolymer
comprising: a) units derived from at least one of: ethylene of
formula A --(CH.sub.2--CH.sub.2).sub.n1-- and propylene of formula
A' --((CH.sub.3)CH.sub.2--CH.sub.2).sub.n2, with n1+n2=n ranging
from 98 to 643, n1 being advantageously equal to n; b) units of
formula B: --(CH.sub.2--CHOOCR.sub.1).sub.m-x-- in which R.sub.1
represents a C.sub.1-C.sub.15 linear or branched alkyl group, in
which the branching is situated at any point of the alkyl radical,
with m ranging from 2 to 105; c) units of formula C:
--(CH.sub.2--CHOH).sub.x1-- in which x1 ranges from 0 to 0.30x; d)
units of formula D: --(CH.sub.2--CHOOCR.sub.2).sub.x2-- in which x2
ranges from 0.70x to x, and R.sub.2 represents a C.sub.8-C.sub.24
saturated or unsaturated, linear or branched, alkyl group, with
x=x.sub.1+x.sub.2.
2. The use according to claim 1, in which the percentage in moles
of units A and/or A' in the copolymer ranges from 79 to 99% in
moles, the percentage in moles of units B in the polymer ranges
from 0 to 19% in moles, the % in moles of units C in the polymer is
close to 0 to 6.3% in moles, the percentage in moles of units D in
the polymer is from 0.1 to 21% in moles.
3. The use according to claim 1, in which the at least one
copolymer is in the form of a concentrated solution in a
hydrocarbon distillate.
4. The use according to claim 1, in which the hydrocarbon liquid
composition is a hydrocarbon distillate containing from 0 to 5,000
ppm of sulphur, and contains 10 to 5,000 ppm of said at least one
copolymer, optionally in a mixture with other additives such as
detergents, dispersants, demulsifiers, anti-foam agents, biocides,
reodorants, cetane improvers, anti-corrosion agents, friction
modifiers, lubricity, combustion, cloud point, pour point
improvers, anti-sedimentation agents and conductivity improvers,
resistance to cold additives, lubricants.
5. The use according to claim 4 in which the distillate comprises
at least one hydrocarbon cut originating from the group constituted
by the distillates with a boiling point comprised between 150 and
450.degree. C., an initial crystallization temperature ICT greater
than or equal to -20.degree. C., comprising distillates from direct
distillation, distillates from vacuum distillation, hydrotreated
distillates, distillates originating from catalytic cracking and/or
hydrocracking of vacuum distillates, distillates resulting from
ARDS type conversion and/or visbreaking processes, distillates
originating from the upgrading of Fischer Tropsch cuts, distillates
resulting from the BTL conversion of vegetable and/or animal
biomass, taken alone or in combination, and esters of vegetable and
animal oils or their mixtures.
6. The use according to claim 5, in which the distillate comprises
a C9 to C40 n-paraffin content comprised between 1 and 40% by
mass.
7. The use according to claim 1 of the copolymer, as a distillate
additive for Diesel fuel comprising from 0 to 500 ppm of
sulphur.
8. The use according to claim 1 of the copolymer as a distillate
additive for heating fuel oil comprising from 0 to 5000 ppm of
sulphur.
9. The use according to claim 1 of the copolymer as a distillate
additive for heavy fuel oil.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a National Phase Entry of International
Application No. PCT/FR2008/001816, filed on Dec. 23, 2008, which
claims priority to French Application 07 09 093, filed on Dec. 26,
2007, both of which are incorporated by reference herein.
TECHNICAL FIELD
[0002] The present invention relates to the synthesis and the use
of novel copolymers based on ethylene and/or propylene and vinyl
ester(s) modified by grafting, effective for improving both the
resistance to cold and the lubricity of liquid hydrocarbons, in
particular middle distillates originating from the distillation of
petroleum and crude oils, in particular those with a low sulphur
content.
BACKGROUND
[0003] For a long time, the oil industry has been developing
additives which promote the filterability of motor fuels at low
temperatures: they are copolymers of ethylene and vinyl acetate
and/or vinyl propionate (EVA or EVP), called CFPP (cold filter
plugging point) additives. Their role is to modify the
crystallization and more particularly to limit the size of the
paraffin crystals formed at low temperature, for example lower than
5.degree. C., with a view to passing through the filters arranged
inside internal combustion engines or in heating installations.
This type of additives, widely known to a person skilled in the
art, is very often added to the middle distillates of standard
type, and in particular those used as Diesel fuels or as heating
fuels. Additional quantities of these additives can be added to the
motor fuels sold in service stations in particular to meet very
cold weather specifications.
[0004] Other types of additives such as copolymers of ethylene,
vinyl acetate and branched vinyl ester such as vinyl neodecanoates
(VeoVA) having a role on the CFPP have been described, in
particular in US 2004/0226216. In order to improve the resistance
to cold, i.e. both the CFPP and the pour point of the distillates,
additives can be added to these CFPP (EVA or EVP) additives which
act either alone or in combination with these additives on the pour
point of the distillates. The prior art copiously describes such
combinations of additives improving both the cold filter plugging
point and the pour point of the hydrocarbon distillates of standard
type at low temperatures.
[0005] Thus, U.S. Pat. No. 3,275,427 describes a middle distillate
of distillation cut comprised between 177 and 400.degree. C.
containing an additive constituted by 90 to 10% by weight of a
copolymer of ethylene comprising from 10 to 30% by weight of vinyl
acetate units of molecular weight comprised between 1,000 and 3,000
and from 10 to 90% by weight of a lauryl polyacrylate and/or lauryl
polymethacrylate with a molecular mass by weight varying from 760
to 100,000. It should be noted that these polyacrylates improve the
filterability temperature determined according to the standard NF
EN116 without damaging the pour point temperature determined by the
standard NF 60105.
[0006] For the transport of the crude oils and heavy distillates by
pipe, the authors of the U.S. Pat. No. 3,726,653 were confronted
with the problem of the improvement of pouring in particular at the
low temperatures at which these products could solidify in the
pipes. In order to improve these properties in hydrocarbon
compositions containing paraffins 5 to 20% by weight of which have
a boiling point greater than 350.degree. C. and a softening point
greater than 35.degree. C., the inventors propose to add to these
compositions from 10 ppm to 2% by weight of a mixture of a polymer
of an olefinic ester of carboxylic acids with 3 to 5 carbon atoms
with an alcohol with 14 to 30 carbon atoms and with a molecular
mass by weight varying from 1,000 to 1,000,000, with a copolymer of
ethylene and vinyl acetate comprising from 1 to 40, preferably from
14 to 24 vinyl acetate units of average molecular weight of 20,000
to 60,000. The molar ratio of the olefinic ester polymer to the
copolymer of ethylene and vinyl acetate varies from 0.1:1 to
10:1.
[0007] In order to control the size of the paraffin crystals
present at levels of at least 3% in middle distillates having a
boiling point comprised between 120.degree. C. and 480.degree. C.,
U.S. Pat. No. 4,153,422 proposes adding to these middle distillates
from 10 ppm to 1% by weight of a mixture of a homopolymer of an
olefinic ester of acrylic or methacrylic acid comprising an alkyl
chain with 14 to 16 carbon atoms and with a molecular mass by
weight varying from 1,000 to 200,000, with an ethylene and vinyl
acetate copolymer with an average numerical molecular weight lower
than 4,000. The molar ratio of olefinic ester homopolymer to
copolymer of ethylene and vinyl acetate varies from 0.1:1 to
20:1.
[0008] In addition to the resistance to cold properties, the liquid
hydrocarbons, in particular the diesel fuels, aviation fuels and
motor fuels or fuel oils for domestic applications (DFO) must have
lubrication abilities for the protection of pumps, injection
systems and/or all moving parts with which these products come into
contact, for example in an internal combustion engine. With the
wish to use purer and purer products which are less and less
polluting, the oil refining industry is led to propose motor fuels
or fuel oils with a sulphur content which is more and more reduced:
since 1.sup.st Jan. 2005 the sulphur level authorized in motor
fuels within the European Union has been limited to 50 ppm and it
must be less than 10 ppm starting from 1.sup.st Jan. 2009. Now, as
the sulphur compounds are eliminated, a loss of the lubricity of
these motor fuels is observed. Below a certain level of
sulphur-containing products, there is even an appreciable
appearance of wear phenomena and even the breakage of moving parts
in pumps and/or injection systems is noticed.
[0009] It is therefore necessary to compensate for the lubricating
effect of the sulphur-containing compounds by the least possible
polluting, and if possible non-polluting, compounds but having a
lubricity sufficient to limit the risks of wear. In order to
resolve this problem, several types of additives have already been
proposed. Thus primarily anti-wear additives, proven in the field
of lubricants, of the unsaturated fatty acid ester and fatty acid
dimer, aliphatic amine, fatty acid and diethanolamine ester and
long-chain aliphatic monocarboxylic acid type as described in U.S.
Pat. No. 2,257,889, U.S. Pat. No. 4,185,594, U.S. Pat. No.
4,204,481, U.S. Pat. No. 4,208,190, U.S. Pat. No. 4,248,182 are
added to the gas oils. Most of these additives have a sufficient
lubricity, but at excessively high concentrations, which is very
detrimental financially. Moreover, the additives containing dimer
acids, like those containing trimer acids, cannot be used in motor
fuels supplying vehicles in which the fuel can be in contact with
the lubrication oil, as the chemical reaction of these acids forms
deposits which are sometimes insoluble in the oil, and more
importantly are incompatible with the detergents usually used.
[0010] U.S. Pat. No. 4,609,376 recommends the use of anti-wear
additives obtained from mono- and poly-carboxylic acid esters and
polyhydroxylated alcohols in motor fuels containing alcohols in
their composition. U.S. Pat. No. 2,686,713 recommends the
introduction of tall oil up to 60 ppm into diesel fuels in order to
prevent the formation of rust on the metal surfaces in contact with
these motor fuels.
[0011] Another route chosen is the introduction of vegetable oil
esters or the vegetable oils themselves into these motor fuels to
improve their lubricity or their anti-friction qualities. These
include the esters derived from rapeseed, flax, soya, sunflower
oils or the oils themselves (see patents EP 635 558 and EP 605
857). One of the major drawbacks of these esters is their low
lubricity at a concentration of less than 0.5% by weight in motor
fuels. In order to improve the lubricity of the gas oils, WO
95/33805 recommends the introduction of a resistance to cold
additive constituted by nitrogen-containing additives comprising
one or more N--R.sub.13 groups in which R.sub.13 comprises 12 to 24
carbon atoms, is linear, slightly branched or alicyclic and
aromatic, the nitrogen group being able to be linked by CO or
CO.sub.2 and to form carboxylates of amines or amides.
[0012] U.S. Pat. No. 3,667,152 describes the use of tall oil acid
(or TOFA, abbreviation of tall oil fatty acid) as an anti-wear
additive. EP 915 944 describes anti-friction additives for
improving the lubricant properties of diesel fuels with a low
sulphur content, constituted by at least one saturated or
unsaturated, C12-C24 monocarboxylic aliphatic hydrocarbon, and at
least one polycyclic hydrocarbon compound chosen from the group
constituted by resin acids, their derivatives (amine carboxylates,
esters and nitriles). These anti-friction additives can be used in
liquid hydrocarbons in the presence of other additives, such as
detergents, pro-cetane additives, demulsifiers, anti-corrosion
additives, additives which improve resistance to cold, odour
modifiers, and also known anti-friction additives.
[0013] WO 94/00536 describes compositions improving the low
temperature properties of fuel oils comprising
[0014] a) terpolymers of ethylene--2 different unsaturated esters
and/or
[0015] b) mixtures of 2 different copolymers [ethylene-1
unsaturated ester or an acrylate] in which the longest ester alkyl
chains are C6 to C13 alkyl chains. EP 1116780 describes
multifunctional additives which improve the cold properties and
lubricity of motor fuels. These additives contain two different
compounds A) 5-95% of an oil-soluble amphiphilic compound and B)
5-95% of a terpolymer of ethylene--C2-C4 vinyl ester--C8-C15
neocarboxylic vinyl ester (i.e. which contains a tertiary C). The
lubricant properties are provided by the amphiphilic compound. U.S.
Pat. No. 5,254,652 describes terpolymers of ethylene--vinyl
acetate--C9 or C10 neoalkanoate vinyl ester which improve the flow
properties of motor fuels at low temperatures.
[0016] A need exists to improve not only the resistance to cold
(filterability temperature and pour point) but also the lubricity
of the motor fuels based on liquid hydrocarbons, in particular
low-sulphur or sulphur-free motor fuels.
SUMMARY
[0017] The present invention, subject of the present application,
relates to copolymers which can advantageously be used as
bifunctional additives which improve both the resistance to cold
and the lubricity of the liquid motor fuels in which they are
incorporated. Thus the first purpose of the invention relates to
the use of these copolymers as additives for motor fuel bases,
preferably of distillate type for diesel fuels or for domestic fuel
oils (DFO).
[0018] The invention therefore relates to the use as a bifunctional
lubricity and resistance to cold additive for liquid hydrocarbon
compositions of at least one copolymer comprising: [0019] units
derived from ethylene of formula A --(CH.sub.2--CH.sub.2).sub.n1--
and/or propylene of formula A'
--((CH.sub.3)CH.sub.2--CH.sub.2).sub.n2 with n1+n2=n ranging from
98 to 643, preferably ranging from 124 to 515; n1 being
advantageously equal to n; [0020] units of formula B:
--(CH.sub.2--CHOOCR.sub.1).sub.m-x-- in which R.sub.1 represents a
C.sub.1-C.sub.15 linear or branched alkyl group, preferably methyl,
propyl, and/or a C5 to C15 branched alkyl group, in which the
branching is situated at any point of the alkyl radical, preferably
in position 2 or 3 of the alkyl chain; preferably chosen from the
preferred C5-C15 vinyl comonomers, preferably chosen from the
pivalate, isopentanoate, isohexanoate, isononanoate, isodecanoate
and/or isotridecanoate, and advantageously 2-ethyl hexanoate,
neoalkanoates, in particular the neononanoate, neodecanoate and/or
neoundecanoate; with m ranging from 2 to 105, preferably ranging
from 16 to 71 and x ranging from 0.2 to 105, preferably ranging
from 1.6 to 71; [0021] units of formula C:
--(CH.sub.2--CHOH).sub.x1-- in which x1 ranges from 0 to 0.30x,
preferably x1=0; [0022] units of formula D:
--(CH.sub.2--CHOOCR.sub.2).sub.x2-- in which x2 ranges from 0.70x
to x, preferably x2=x, and R.sub.2 represents a C.sub.8-C.sub.24
saturated or unsaturated, linear or branched, alkyl group,
preferably C.sub.14-C.sub.20 or also C.sub.14 to C.sub.18 [0023]
with x=x.sub.1+x.sub.2
[0024] Preferably, the percentage in moles of units A and/or A' in
the copolymer ranges from 79 to 99% in moles, preferably 86.7 to
90.7% in moles; the percentage in moles of units B in the polymer
ranges from 0 to 19% in moles, preferably 4.6 to 12% in moles; the
% in moles of units C in the polymer is close to 0 to 6.3% in moles
and advantageously equal to 0% in moles; the percentage in moles of
units D in the polymer is from 0.1 to 10% in moles, 0.1 to 21% in
moles, preferably 0.93 to 8.6% in moles. Preferably, said at least
one copolymer is in the form of a concentrated solution in a
hydrocarbon distillate, preferably at a concentration of more than
50% by weight, preferably more than 70% by weight or preferably
more than 80% by weight, preferably 60 to 80% by weight.
[0025] According to a preferred embodiment, the hydrocarbon liquid
composition is a hydrocarbon distillate containing from 0 to 5,000
ppm of sulphur, and contains 10 to 5,000 ppm of said at least one
copolymer, optionally in a mixture with other additives such as
detergents, dispersants, demulsifiers, anti-foam agents, biocides,
reodorants, cetane improvers, anti-corrosion agents, friction
modifiers, lubricity, combustion, cloud point, pour point
improvers, anti-sedimentation agents and conductivity improvers,
resistance to cold additives, lubricants. According to a preferred
embodiment, the distillate comprises at least one hydrocarbon cut
originating from the group constituted by the distillates with a
boiling point comprised between 150 and 450.degree. C., an initial
crystallization temperature ICT greater than or equal to
-20.degree. C., preferably greater than or equal to -15.degree. C.,
preferably comprised between -15.degree. C. and +10.degree. C.,
comprising distillates from direct distillation, distillates from
vacuum distillation, hydrotreated distillates, distillates
originating from catalytic cracking and/or hydrocracking of vacuum
distillates, distillates resulting from ARDS type conversion and/or
visbreaking processes, distillates originating from the upgrading
of Fischer Tropsch cuts, distillates resulting from the BTL
conversion of vegetable and/or animal biomass, taken alone or in a
mixture, and esters of vegetable and animal oils or their
mixtures.
[0026] Preferably, the distillate comprises a C9 to C40 n-paraffin
content comprised between 1 and 40% by mass. Preferably, said
copolymer, as a distillate additive for Diesel fuel comprises from
0 to 500 ppm of sulphur. Preferably, said copolymer as a distillate
additive for heating fuel oil comprises from 0 to 5,000 ppm of
sulphur. According to a preferred embodiment, said copolymer is
intended as a distillate additive for heavy fuel oil.
[0027] The second purpose is to provide a process for the
preparation of these novel polymers via an esterification process
of the vinyl ester units which have been hydrolyzed previously
either in part or in total. The third purpose of the present
invention relates to the novel copolymers of ethylene and/or
propylene and vinyl ester(s) as mentioned above which are
chemically modified by grafting branchings essentially derived from
fatty acid(s) in particular for their use in motor fuel bases as
bifunctional additives.
[0028] These motor fuel bases are in general rich in paraffins,
weakly aromatic and as a result have a low solvent power. The
addition of the copolymers according to the present invention
therefore applies not only to the distillates originating from the
direct distillation of hydrocarbons originating from crude oils
with a very high paraffin content but also to the hydrocarbons
originating from the heaviest cuts of refining operations i.e.
cracking, hydrocracking and catalytic cracking processes and
visbreaking processes or also the synthetic distillates originating
from the conversion of gas and/or coal such as those originating
from the Fischer Tropsch process, but also those resulting from the
treatment of vegetable and/or animal biomass, such as in particular
NexBTL and the distillates containing esters of vegetable and/or
animal oils, taken alone or in a mixture.
[0029] The present invention relates to copolymers comprising:
[0030] a) units derived from ethylene of formula A
--(CH.sub.2--CH.sub.2).sub.n1-- and/or propylene of formula A'
--((CH.sub.3)CH.sub.2--CH.sub.2).sub.n2 with n1+n2=n ranging from
98 to 643, preferably ranging from 124 to 515; n1 being
advantageously equal to n;
[0031] b) units of formula B: --(CH.sub.2CHOOCR.sub.1).sub.m-- in
which R.sub.1 represents a C.sub.1-C.sub.15 linear or branched
alkyl group, preferably methyl, ethyl, and/or a C5 to C15 branched
alkyl group, in which the branching is situated at any point of the
alkyl radical, preferably in position 2 or 3 of the alkyl chain;
among the preferred C5-C15 vinyl comonomers, there can be mentioned
the pivalate, isopentanoate, isohexanoate, isononanoate,
isodecanoate and/or isotridecanoate, and advantageously 2-ethyl
hexanoate, neoalkanoates, in particular the neononanoate,
neodecanoate and/or neoundecanoate; with m ranging from 2 to 105,
preferably ranging from 16 to 71 and x ranging from 0.2 to 105,
preferably ranging from 1.6 to 71;
[0032] c) units of formula C: --(CH.sub.2--CHOH).sub.x1-- in which
x1 ranges from 0 to 0.30x, preferably x1=0;
[0033] d) units of formula D: --(CH.sub.2--CHOOCR.sub.2).sub.x2--
in which x2 ranges from 0.70x to x, preferably x2=x, and R.sub.2
represents a C.sub.8-C.sub.24 saturated or unsaturated, linear or
branched alkyl group and preferably C.sub.14--O.sub.20 or also
C.sub.14 to C.sub.18;
[0034] with x=x.sub.1+x.sub.2.
Advantageously, the percentage in moles of units A and/or A' in the
copolymer can represent from 79 to 99% in moles, preferably 86.7 to
90.7% in moles;
[0035] the percentage in moles of units B can represent from 0 to
19% in moles, preferably 4.6 to 12% in moles;
[0036] the percentage in moles of units C can represent from 0 to
6.3% in moles, preferably the percentage in moles of units C is
close to, or even equal to 0% in moles;
[0037] the percentage in moles of units D can represent from 0.1 to
21% in moles, preferably 0.93 to 8.6% in moles.
[0038] The present invention also relates to the process for the
preparation of the copolymers according to the invention as defined
previously; this process comprises the following stages:
[0039] 1) providing a starting copolymer of ethylene and/or
propylene and vinyl ester(s) comprising:
[0040] a) units derived from ethylene of formula A
--(CH.sub.2--CH.sub.2).sub.n1-- and/or propylene of formula A'
--((CH.sub.3)CH.sub.2--CH.sub.2).sub.n2 with n1+n2=n and
[0041] b) units of formula B: --(CH.sub.2--CHOCOR.sub.1).sub.m-- in
which R.sub.1 is chosen from the C.sub.1-C.sub.15 linear or
branched alkyl groups, alone or in a mixture, and preferably
comprises the methyl group and/or the ethyl group and/or a C5 to
015 branched alkyl groups, as defined previously;
[0042] n and m being as defined previously;
[0043] 2) hydrolysis reaction, at least partial, of the alkyl
esters present in units B, then
[0044] 3) esterification reaction, at least partial, and preferably
total, of these hydrolyzed sites by at least one fatty acid of
formula R2COOH, R2 being as defined previously and/or at least one
fatty acid derivative such as an acid anhydride, acid halide,
preferably acid chloride; the esterification level is preferably
greater than 50%, advantageously greater than 80%, and particularly
advantageously equal to 100%.
[0045] Another process for the preparation of copolymers consists
in carrying out a transesterification of a copolymer as defined in
1) with an alcohol of type R2CH.sub.2OH; a transesterification
process is for example described in WO 94/00536. The starting
copolymers used in stage 1) are random copolymers comprising:
[0046] a) units derived from ethylene of formula A
--(CH.sub.2--CH.sub.2).sub.n-- and/or from propylene of formula A'
--((CH.sub.3)CH.sub.2--CH.sub.2).sub.n2 with n1+n2=n;
[0047] b) units of formula B: --(CH.sub.2--CHOCOR.sub.1).sub.m-- in
which R.sub.1 is chosen from C.sub.1-C.sub.15 linear or branched
alkyl group,
[0048] n and m being as defined previously.
[0049] The copolymers according to the invention have an average
numerical molar weight Mn measured by polystyrene standard
calibration GPC, comprised in general between 4,500 and 20,000
gmol.sup.-1. The copolymer obtained at the end of stage 2) is
obtained by a stage of partial or total hydrolysis of the ester
groups of the starting copolymer of ethylene and/or propylene and
vinyl ester(s) described above.
[0050] In general, the hydrolysis rate can represent from 10 to
100% of the hydrolysable sites (units B). The hydrolysis can be
direct or obtained by transesterification in an acid or basic
medium preferably by basic methanolysis; the conversion rate of the
vinyl ester groups to vinyl alcohol groups is controlled by the
volume of methanolic soda solution introduced (in the case of
transesterification in a basic medium). Thus, by varying the
hydrolysis rate of stage a) of the process, the number of esters
grafted on the final copolymer is therefore varied. The hydrolysis
stage 2) is followed by at least one esterification of the vinyl
alcohol groups formed in the previous stage by one or more fatty
acids (stage 3) preferably converted to acid chlorides, for example
using oxalyl chloride, in order to improve the esterification
yield.
[0051] Within the meaning of the present invention, by fatty acid
is meant an aliphatic carboxylic acid deriving from, or contained
in, animal and/or vegetable fats, oils or waxes. The natural fatty
acids have a saturated or unsaturated, linear, branched and/or
cyclic carbon-containing chain with 4 to 28 carbon atoms (generally
an even number); preferably, the fatty acids are chosen from the
acids having a C.sub.8 to O.sub.24 non-cyclic hydrocarbon chain,
alone or in a mixture, such as stearic acid, oleic acid, linoleic
acid, palmitic acid and/or linolenic acid, and are advantageously
chosen from the fatty acids having at least one unsaturation.
[0052] The scope of the invention would not be exceeded if the
esterification stage was implemented using fatty acids derived from
tall oil, which are better known by the abbreviation TOFA (tall oil
fatty acids). These TOFAs are in general obtained by distillation
of the tall oil, which is a by-product of the production of pine
wood pulp by the sulphate process; they comprise a major quantity
of fatty acids as defined above as well as a minor quantity of
resin acids, such as abietic, dihydroabietic, tetrahydroabietic,
dehydroabietic, neoabietic, pimaric, levopimaric, and/or
parastrinic acids, etc. The grafted copolymers obtained can also
contain ester functions of resin acids formed from the resin acids
present in the mixture of acids used.
[0053] At the end of stage 3) (esterification of the copolymer
originating from stage 2)), a grafted copolymer is obtained which
is partially or preferably totally esterified. The copolymers
according to the invention can be advantageously used as obtained
at the end of stage 3) as additives for liquid hydrocarbons, motor
fuels and fuel oils.
[0054] The copolymers according to the invention have good
solubility in the hydrocarbons of middle distillate type, greater
than that of the copolymers of ethylene and/or propylene and vinyl
ester(s) of the prior art, such as EVA or EVP. This allows a
significant improvement in the filterability characteristics of the
motor fuels or other fuels with additives or the blocking tendency
characteristics (standard IP 387) of the motor fuels and other
fuels with additives. It is noted that the solubility of the
copolymers according to the invention is improved with respect to
that of the copolymers of EVA and/EVP when the FBT (Filter Blocking
Tendency) values are measured; in practice, this better solubility
of the compositions of hydrocarbons supplemented with the
copolymers according to the invention allows blocking of the
filters (of diameter in general equal to 1.6 .mu.m) to be
avoided.
[0055] The improvement in solubility of the copolymers according to
the invention allows hydrocarbons with additives to be obtained
which retain their initial filterability characteristics at ambient
temperature and remain perfectly filterable in filtration systems
that can be encountered for example in the fuel systems of engines
and heating installations. In addition, the lower viscosity of the
copolymers in comparison to EVA and/or EVP makes it possible to
achieve concentrated solutions of copolymer(s) according to the
invention in the hydrocarbons with a reduced level of aromatic
solvent without detriment to the pumpability and use of these
solutions (constraints of viscosity and of rheological behaviour in
the pumping or injection systems).
[0056] The copolymers according to the invention can also be used
in the form of a concentrated solution in a solvent, in general in
a hydrocarbon distillate, preferably at a concentration of more
than 50% by weight, preferably more than 70% by weight, or
advantageously at a concentration greater than or equal to 80%;
concentrated solutions in a solvent, in general in a hydrocarbon
distillate which are also preferred comprise 60 to 80% by weight of
copolymer(s) according to the invention. These copolymers according
to the invention or preferably their concentrated solutions as
defined above are in particular used as bifunctional additives:
both as filterability additives, i.e. additives making it possible
to lower the cold filter plugging point (CFPP) of compositions
based on liquid hydrocarbons and as additives which improve the
lubricity or anti-friction additives for these compositions based
on liquid hydrocarbons.
[0057] The compositions of liquid hydrocarbons in general originate
from oil refining operations, in particular from the direct
distillation of hydrocarbons but can also originate from thermal
cracking, hydrocracking and/or catalytic cracking processes and
visbreaking processes. They are preferably middle distillates that
can be used as diesel fuels, domestic heating fuel oils (DFO),
kerosene, heavy fuel oils.
[0058] With increasing demand for motor fuels, in particular
diesel, refiners are looking to introduce cuts from sources other
than petroleum which are more difficult to use in these fuels as
they can lead to poorer resistance to cold behaviour in the latter,
by increasing their cold filter plugging point and flow
temperature. Among these novel sources of distillates, there can in
particular be mentioned: [0059] the heaviest cuts originating from
the cracking and visbreaking processes, with a high concentration
of heavy paraffins, comprising more than 18 carbon atoms, [0060]
the synthetic distillates originating from the conversion of gas
such as those originating from the Fischer Tropsch process, [0061]
the synthetic distillates resulting from the treatment of biomass
of vegetable and/or animal origin, such as in particular NexBTL,
[0062] and the oils and/or esters of vegetable or animal oils.
These novel motor fuel bases can be used alone or in a mixture with
standard petroleum middle distillates defined above as motor fuel
base and/or domestic fuel oil base; they generally comprise long
paraffinic chains greater than or equal to 16 carbon atoms.
[0063] The liquid hydrocarbon compositions according to the
invention comprise a major proportion of liquid hydrocarbons,
preferably of middle distillate type, with a sulphur content
preferably lower than 5,000 ppm, preferably lower than 500 ppm, and
more preferably lower than 50 ppm, and a minor proportion
comprising at least one copolymer according to the invention.
Preferably, in the distillates according to the invention, the
major proportion is constituted by the distillates with a boiling
point comprised between 150 and 450.degree. C., initial
crystallization temperature ICT greater than or equal to
-20.degree. C., preferably greater than or equal to -15.degree. C.,
preferably comprised between -15.degree. C. and +10.degree. C., and
comprises distillates from direct distillation, distillates from
vacuum distillation, hydrotreated distillates, distillates
originating from catalytic cracking and/or hydrocracking of vacuum
distillates, distillates resulting from ARDS (atmospheric residue
desulphuration) type conversion and/or visbreaking processes,
distillates originating from the upgrading of Fischer Tropsch cuts,
distillates resulting from the BTL (biomass to liquid) conversion
of vegetable and/or animal biomass, taken alone or in combination,
and esters of vegetable and animal oils or their mixtures.
According to a preferred embodiment of the invention, the
distillates according to the invention have a C9 to C40 n-paraffin
content comprised between 1 and 40% by mass.
[0064] According to another subject, the invention relates to a
Diesel fuel comprising from 0 to 500 ppm of sulphur and comprising
at least one distillate according to the invention. According to
another subject, the invention relates to a heating fuel oil
comprising from 0 to 5,000 ppm of sulphur and comprising at least
one distillate according to the invention. According to another
subject, the invention relates to a heavy fuel oil comprising at
least one distillate according to the invention.
[0065] According to a preferred embodiment of the invention, the
hydrocarbon compositions contain from 10 to 5,000 ppm by weight,
preferably from 10 to 1,000 ppm of at least one copolymer according
to the invention. Apart from the bifunctional additive or additives
according to the invention, the hydrocarbon compositions can also
contain one or more others which are different, chosen from the
detergents, anti-corrosion agents, dispersants, demulsifiers,
anti-foam agents, biocides, reodorants, procetane additives,
friction modifiers, combustion-promoting agents (catalytic
combustion and soot promoters), agents improving the cloud point,
pour point, cold filter plugging point, anti-sedimentation agents,
anti-wear agents and/or conductivity modifying agents, or even one
or more other additives which improve the pour point, the cold
filter plugging point, and the lubricity.
[0066] Among these additives, there can be mentioned
particularly:
[0067] a) procetane additives, in particular (but not limitatively)
chosen from alkyl nitrates, preferably 2-ethyl hexyl nitrate, aroyl
peroxides, preferably benzyl peroxide, and alkyl peroxides,
preferably ter-butyl peroxide;
[0068] b) anti-foam additives, in particular (but not limitatively)
chosen from polysiloxanes, oxyalkylated polysiloxanes, and amides
of fatty acids originating from vegetable or animal oils. Examples
of such additives are given in EP 861 882, EP 663 000, EP 736
590;
[0069] c) detergent and/or anti-corrosion additives, in particular
(but not limitatively) chosen from the group constituted by amines,
succinimides, alkenylsuccinimides, polyalkylamines, polyalkyl
polyamines and polyetheramines. Examples of such additives are
given in EP 938 535;
[0070] d) lubricity additive or anti-wear agent, in particular (but
not limitatively) chosen from the group constituted by fatty acids
and their ester or amide derivatives, in particular glycerol
monooleate, and derivatives of mono- and polycyclic carboxylic
acids. Examples of such additives are given in the following
documents: EP 680 506, EP 860 494, WO 98/04656, EP 915 944, FR2772
783, FR 2 772 784;
[0071] e) cloud point additives, in particular (but not
limitatively) chosen from the group constituted by terpolymers of
long chain olefin/(meth)acrylic ester/maleimide, and polymers of
fumaric/maleic acid esters. Examples of such additives are given in
EP 71 513, EP 100 248, FR 2 528 051, FR 2 528 051, FR 2 528 423,
EP1 12 195, EP 1 727 58, EP 271 385, EP 291 367;
[0072] f) anti-sedimentation or dispersant additives, in particular
(but not limitatively) chosen from the group constituted by
copolymers of (meth)acrylic acid/alkyl(meth)acrylate amidified by a
polyamine, polyamine alkenylsuccinimides, derivatives of phthalic
acid and a double chain fatty amine; alkyl phenol resins. Examples
of such additives are given in EP 261 959, EP593 331, EP 674 689,
EP 327 423, EP 512 889, EP 832 172, US2005/0223631; U.S. Pat. No.
5,998,530; WO 93/14178;
[0073] g) multifunctional cold operability additives chosen from
the group constituted by the polymers based on olefin and alkenyl
nitrate as described in EP 573 490;
[0074] h) resistance to cold additives such as copolymers of alpha
olefin and vinyl ester(s) such as EVA, EVP, copolymers of ethylene,
vinyl acetate and branched vinyl ester such as vinyl neodecanoates
(VEOVA) described in particular in US 2004/0226216;
[0075] i) lubricants such as fatty acids, TOFAs, their derivatives
such as esters, in particular.
[0076] These other additives are in general added in a quantity
ranging from 10 to 1,000 ppm (each). The bifunctional additives
according to the invention can be added to the hydrocarbon
compositions within the refinery, and/or be incorporated downstream
of the refinery, optionally in a mixture with other additives, in
the form of a package of additives.
DETAILED DESCRIPTION
Example of the Preparation of the Grafted Polymers
[0077] Starting with the same copolymer of ethylene and vinyl
acetate EVA containing 28% by weight of vinyl acetate (denoted EVA
28), i.e. 11.2% in moles, of average numerical molar weight=5,000
gmol.sup.-1 measured by polystyrene standard GPC, 4 types of
different grafts (units D) denoted D1 to D4 were grafted, according
to the preparation process according to the invention. D1 is a TOFA
(mixture of acids derived from tall oil, containing from 2 to 3% by
weight of resin acids and a mixture of C8 to C24, but mostly C18,
fatty acids; its concentration of saturated and/or unsaturated
C14-C18 fatty acids can vary from 80 to 90%). The copolymer grafted
with D1 can also comprise resin acid ester functions formed from
the resin acids present in the mixture of acids derived from tall
oil.
[0078] D2 to D4 are mixtures of saturated and unsaturated C14 to
C18 fatty acids the molar composition of which in fatty acids is
shown in detail in Table 1 below.
TABLE-US-00001 TABLE 1 Grafted acid C.sub.14 C.sub.16 C.sub.18
C.sub.18-1 C.sub.18-2 C.sub.18-3 D1 -- 0.6 1.4 30.8 41.1 10.7 D2
>86 <14 D3 1.8 16.6 11.6 24.6 39.3 6.1 D4 1 45 5 38 11 --
[0079] The characteristics of the grafted copolymers (% in moles of
units A to D are compiled in Table 2.
TABLE-US-00002 TABLE 2 % in moles % in moles % in moles % in moles
% by Starting Type of of units A of units B of units C of units D
weight Polymer polymer graft (n1) (m - x) (x.sub.1) (x.sub.2) of
units D 1 EVA28 none 88.8 (130) 11.2 (16) 0 (0) 0 (0) 0 2 EVA28 D1
88.8 (130) 9.07 (13) 0 (0) 2.13 (3) 15 3 EVA28 D1 88.8 (130) 7.95
(11) 0 (0) 3.25 (5) 21.7 4 EVA28 D1 88.8 (130) 6.68 (10) 0 (0) 4.52
(6) 28 5 EVA28 D1 88.8 (130) 5.15 (7) 0 (0) 6.05 (9) 35 7 EVA28 D2
88.8 (130) 7.05 (10) 0 (0) 4.15 (6) 26 8 EVA28 D3 88.8 (130) 7.05
(10) 0 (0) 4.15 (6) 26 9 EVA28 D4 88.8 (130) 4.18 (6) 0 (0) 7.02
(10) 38.5
[0080] The cold filter plugging points of 5 GOM middle distillates
denoted "a" to "e" of EN 590 engine gas oil type, the
characteristics of which are compiled in Table 3 below, with one of
the copolymers 1 to 9 added at concentrations comprised between 35
and 700 ppm by weight, were measured.
TABLE-US-00003 TABLE 3 Characteristics of the gas oils tested
Distillation ASTM D86 GOM a GOM b GOM c GOM d GOM e T90-T20 112.7
100.5 112 110 MP-T90 18.6 17 23 18 T95 (.degree. C.) 353.9 350 356
352 Cloud point (.degree. C.) -4 -9 -7 -7 -6 NF EN 23015 CFPP
(.degree. C.) EN 116 -5 -9 -6 -7 -7 Pour point (.degree. C.) -12
-15 -9 -9 -12 NF T 60105 Paraffins (% by mass) 19.27 16.1 15.64
18.73 Chromatography ICT (.degree. C.) IP 389 -6 -12.6 -9.5 -12
Sulphur content (ppm) 39.8 9.2 48 35 9 EN ISO 20846
[0081] The FBT (filter blocking tendency) was also measured
according to the standard IP387 of a solution containing 420 ppm of
copolymer 1 to 9 (solution prepared from a stock solution with 4%
by mass of copolymer) as well as the lubricity measured under HFRR
test conditions (High Frequency Reciprocating Rig EN ISO 12156-1 or
as described in the article SAE 932692 by J. W. Hadley of the
University of Liverpool) with a copolymer concentration of 210 ppm
and/or 420 ppm respectively. The test involves jointly subjecting a
steel sphere in contact with a stationary metal plate to a pressure
corresponding to a weight of 200 g and an alternating movement of 1
mm at a frequency of 50 Hz. The lubricity is expressed by the
average value of the diameters of the wear scar of the sphere on
the plate. A small diameter (generally less than 400 .mu.m)
reflects good lubricity; and conversely, a large wear diameter
(greater than 400 .mu.m) reflects a lubricity which is all the more
insufficient, the greater the diameter.
[0082] The results are compiled in Table 4 below.
TABLE-US-00004 TABLE 4 HFRR HFRR CFPP CFPP CFPP CFPP CFPP CFPP
.DELTA.T = 1.4 .DELTA.T = 1.4 (35 (70 (140 (210 (350 (700 FBT
(.mu.m) (.mu.m) ppm) ppm) ppm) ppm) ppm) ppm) at 420 at 210 at 420
Polymer Distillate (.degree. C.) (.degree. C.) (.degree. C.)
(.degree. C.) (.degree. C.) (.degree. C.) ppm ppm ppm 1 a -8 -13
-15 4.4 556 2 a -9 -16 -15 1.69 415 3 a 1.06 4 a -13 -15 -14 1.01
407 5 a -13 -16 -15 1.07 531 513 7 a -12 -14 -14 8 a -9 -10 -13 9 a
-8 -15 -12 1.04 1 b -10 -12 -13 3 b -11 -13 -13 4 b -12 -13 -20 5 b
-12 -13 -24 1 c -10 -12 -15 3 c -15 -16 4 c -15 -18 -17 5 c -16 -19
-18 1 d -15 -17 5 d -18 -21 1 e -13 -17 -19 549 3 e -14 -19 562 4 e
-15 -18 395 5 e -15 -20 -20 570
The lubricities (HFRR WS 1.4) of the GOM middle distillate denoted
"a" with variables quantities ranging from 0 to 84 ppm of D1 alone,
of copolymer 2, 4 or 5 alone or of a mixture of copolymer 2, 4 or 5
and D1 added to it are compared.
[0083] The results are given in Table 5 below.
TABLE-US-00005 TABLE 5 Copolymer No. -- 2 4 5 -- 2 -- 4 -- D1 alone
introduced into 0 0 0 0 34 34 60 60 84 GOM a (ppm by mass)
copolymer i in 0 210 210 210 0 210 0 210 0 GOM a (ppm by mass) HFRR
WS 1.4 497 415 407 513 455 465 366 409 349 (.mu.m)
[0084] The lubricities (WS 1.4) of the GOM middle distillate
denoted "e", which is more "severe" than GOM denoted "a", with
variable quantities ranging from 0 to 200 ppm of D1 alone, or of
one of the copolymers 2 to 5 alone or of a mixture of a copolymer 2
to 5 and D1 added to it are compared. In order to avoid any change
in the samples during storage and preparation operations, the
grafted polymer solutions are stabilized with an antioxidant,
butylated hydroxytoluene or 2,6-di-tert-butyl-4-methylphenol (BHT)
at a concentration of 0.05% to 0.1% with respect to D1.
[0085] The results are compiled in Table 6 below.
TABLE-US-00006 TABLE 6 Copolymer No. -- 2 3 -- 4 5 5 -- Total
quantity 0 63 90 100 118 150 150 200 of free D1 in GOM e (ppm by
mass) D1 alone intro- No No No Yes No No Yes Yes duced into GOM e
Copolymer i in No Yes Yes No Yes Yes Yes No GOM e HFRR WS 1.4 658
549 562 505 395 465 570 392 (.mu.m)
TABLE-US-00007 TABLE 7 Total additives WS1.4 D1 (ppm) (ppm by mass)
(.mu.m) GOM e + D1 0 0 658 (comparative) 100 100 505 150 150 423
200 200 392 250 250 368 GOM e + copolymer 4 + D1 0 0 658 115 330
424 135 350 401 160 375 301 185 400 312 248 450 306 285 500 327 GOM
e + copolymer 4 0 0 658 85 300 577 118 420 395 150 532 297 185 656
266
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