U.S. patent application number 14/427812 was filed with the patent office on 2015-08-20 for composition to improve low temperature properties and oxidation stability of vegetable oils and animal fats.
This patent application is currently assigned to EVONIK OIL ADDITIVES GMBH. The applicant listed for this patent is Jane BENITO, Lisa BRUNNER, Rhishikesh GOKHALE, Justin August LANGSTON, Frank-Olaf MAHLING, Ronny SONDJAJA, Torsten STOHR, Gwen TEH. Invention is credited to Jane Benito, Lisa Bruenner, Rhishikesh Gokhale, Justin August Langston, Frank-Olaf Maehling, Ronny Sondjaja, Torsten Stoehr, Gwen Teh.
Application Number | 20150232783 14/427812 |
Document ID | / |
Family ID | 46967989 |
Filed Date | 2015-08-20 |
United States Patent
Application |
20150232783 |
Kind Code |
A1 |
Gokhale; Rhishikesh ; et
al. |
August 20, 2015 |
COMPOSITION TO IMPROVE LOW TEMPERATURE PROPERTIES AND OXIDATION
STABILITY OF VEGETABLE OILS AND ANIMAL FATS
Abstract
The present invention describes a composition comprising: (A) at
least one polyalkyl (meth) acrylate polymer having a number average
molecular weight M.sub.n of from 15000 to 75000 g/mol; (B) at least
one ethylene vinyl acetate copolymer comprising units being derived
from at least one alkyl (meth) acrylate having 1 to 30 carbon atoms
in the alkyl residue; (C) a phenolic type anti-oxidant; (D) a
mixture stabilizer; and (E) a glycol ether solvent. The composition
is useful as cold flow improver and oxidation stabilizer in
vegetable oils and animal fats.
Inventors: |
Gokhale; Rhishikesh;
(Darmstadt, DE) ; Sondjaja; Ronny; (Darmstadt,
DE) ; Bruenner; Lisa; (Pfungstadt, DE) ;
Maehling; Frank-Olaf; (Mannheim, DE) ; Langston;
Justin August; (Kutztown, PA) ; Stoehr; Torsten;
(Frankfurt, DE) ; Benito; Jane; (Horsham, PA)
; Teh; Gwen; (Klang, MY) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
GOKHALE; Rhishikesh
SONDJAJA; Ronny
BRUNNER; Lisa
MAHLING; Frank-Olaf
LANGSTON; Justin August
STOHR; Torsten
BENITO; Jane
TEH; Gwen |
Darmstadt
Pfungstadt
Mannheim
Kutztown
Frankfurt |
PA |
US
DE
DE
DE
US
DE
US
US |
|
|
Assignee: |
EVONIK OIL ADDITIVES GMBH
Darmstadt
DE
|
Family ID: |
46967989 |
Appl. No.: |
14/427812 |
Filed: |
September 6, 2013 |
PCT Filed: |
September 6, 2013 |
PCT NO: |
PCT/EP2013/068469 |
371 Date: |
March 12, 2015 |
Current U.S.
Class: |
508/467 |
Current CPC
Class: |
C10M 2207/024 20130101;
C10N 2030/10 20130101; C10M 2209/062 20130101; C10L 1/143 20130101;
C10M 2209/084 20130101; C10M 2207/046 20130101; C10L 1/1835
20130101; C10M 2207/401 20130101; C10L 1/1955 20130101; C10N
2030/02 20130101; C10L 1/1852 20130101; C10M 2207/023 20130101;
C10L 1/191 20130101; C10L 1/1963 20130101; C10M 2207/026 20130101;
C10M 169/044 20130101 |
International
Class: |
C10M 169/04 20060101
C10M169/04 |
Foreign Application Data
Date |
Code |
Application Number |
Sep 13, 2012 |
EP |
12184289.2 |
Claims
1. A composition, comprising (A) 35% to 50% by weight of a
polyalkyl (meth)acrylate polymer; (B) 5% to 15% by weight of an
ethylene vinyl acetate copolymer comprising a unit derived from at
least one alkyl (meth)acrylate having 1 to 30 carbon atoms in the
alkyl residue; (C) 10% to 20% by weight of a phenolic type
antioxidant; (D) 10% to 25% by weight of a mixture stabilizer; and
(E) 10% to 20% by weight of a glycol ether solvent wherein the sum
of all components (A) to (E) of the composition adds up to 100% by
weight.
2. The composition according to claim 1, wherein the polyalkyl
(meth)acrylate polymer of component (A) comprises: (a) 0 to 40% by
weight, based on the total weight of the polymer, of a unit derived
from one or more alkyl(meth)acrylate monomers of formula (I)
##STR00004## wherein R denotes hydrogen or methyl and R.sup.1
denotes a linear, branched or cyclic alkyl residue with 1 to 6
carbon atoms; (b) 40 to 99% by weight, based on the total weight of
the polymer, of a unit derived from one or more alkyl(meth)acrylate
monomers of formula (II) ##STR00005## wherein R denotes hydrogen or
methyl and R.sup.2 denotes a linear, branched or cyclic alkyl
residue with 7 to 15 carbon atoms; and (c) 0.1 to 40% by weight,
based on the total weight of the polymer, of a unit derived from
one or more alkyl(meth)acrylate monomers of formula (III)
##STR00006## wherein R denotes hydrogen or methyl and R.sup.3
denotes a linear, branched or cyclic alkyl residue with 16 to 30
carbon atoms, wherein the sum of all components (a) to (c) adds up
to 100% by weight.
3. The composition according to claim 1, wherein the ethylene vinyl
acetate copolymer of component (B) comprises: (i) from 2 to 40% by
weight of vinyl acetate; (ii) from 30 to 80% by weight of a unit
derived from at least one alkyl (meth)acrylate having 1 to 30
carbon atoms in the alkyl residue; and (iii) from 5 to 40% by
weight of a unit derived from ethylene, wherein the sum of all
components (i) to (iii) adds up to 100% by weight.
4. The composition according to claim 1, wherein the ethylene vinyl
acetate copolymer of component (B) comprises from 30 to 90% by
weight of a unit derived from at least one alkyl (meth)acrylate
having 7 to 20 carbon atoms in the alkyl residue.
5. The composition according to claim 1, wherein the ethylene vinyl
acetate copolymer of component (B) is a graft copolymer having an
ethylene vinyl acetate copolymer as graft base and an alkyl
(meth)acrylate having 1 to 30 carbon atoms in the alkyl residue as
graft layer.
6. The composition according to claim 5, wherein the weight ratio
of graft base to graft layer is in the range of from 1:1 to
1:20.
7. The composition according to claim 1, wherein the
polyalkyl(meth)acrylate polymer of component (A) comprises at least
50% by weight of a unit derived from an alkyl (meth)acrylate having
7 to 20 carbon atoms in the alkyl residue.
8. The composition according to claim 7, wherein the polydispersity
M.sub.w/M.sub.n of said polyalkyl(meth)acrylate polymer is in the
range of from 1.1 to 5.
9. The composition according claim 1, wherein the weight ratio of
the polyalkyl(meth)acrylate polymer of component (A) to the
ethylene vinyl acetate copolymer of component (B) is in the range
of from 15:1 to 1:1.
10. The composition according to claim 1, wherein the weight ratio
of the phenolic type antioxidant of component (C) to the ethylene
vinyl acetate copolymer of component (B) is in the range of from
5:1 to 1:5.
11. The composition according to claim 1, wherein the phenolic type
antioxidant of component (C) is a phenolic compound having 2 or
more hydroxyl groups.
12. The composition according to claim 1, wherein the mixture
stabilizer of component (D) is a sterically hindered phenol.
13. The composition according to claim 12, wherein said sterically
hindered phenol is 2,4-di-tert-butylhydroxytoluene.
14. The composition according to claim 1, further comprising at
least one additive selected from the group consisting of a
dispersant, a demulsifier, a defoamer, a lubricity additive, an
additional antioxidant, a cetane number improver, a detergent, a
dye, a corrosion inhibitor, a metal deactivator, a metal passivator
and an odorant.
15. A method of lowering a pour point of a vegetable oil or an
animal fat, the method comprising adding the composition of claim 1
to a vegetable oil or an animal fat.
16. A method of improving an oxidation stability of a vegetable oil
or an animal fat, the method comprising adding the composition of
claim 1 to a vegetable oil or an animal fat.
17. A lubricant, comprising: (I) 0.01 to 4% by weight of the
composition according to claim 1, based on the total weight of the
lubricant; and (II) 96 to 99.9% by weight of a vegetable or an
animal fat, based on the total weight of the lubricant.
18. The lubricant according to claim 17, wherein component (I) is
present in an amount of 0.05% by weight and component (II) is
present in an amount of 98 to 99.5% by weight, each based on the
total weight of the lubricant.
Description
[0001] The present invention relates to an additive composition to
improve low temperature properties and oxidation stability of
vegetable oils and animal fats.
[0002] Due to growing environmental concerns, there has been an
increasing interest and demand for environmental-friendly and
bio-compatible products, which could find applications in
lubrication industry (e.g. "engine lubricants" such as gasoline
engine oils, diesel engine oils, two-stroke engine oils, marine
diesel oils, aviation engine oils, etc and "non-engine" lubricants
such as transmission fluid, gear oils, metalworking fluids, greases
etc.). Besides lubrication industry, environmental-friendly
products are also in demand from the other sectors, which could
function as transformer oils, dielectric fluids, refrigeration
oils, etc. One such example disclosing a vegetable oil based
dielectric fluid for use in electrical appliances is given in U.S.
Pat. No. 6,398,986 B1 (Cooper Industries, Inc.).
[0003] One of the most abundant sources for the development of
environmental-friendly products is "nature-derived", in the form of
natural oils and fats. For example, the natural oil can be a
vegetable oil such as sunflower oil, rapeseed oil, soya oil,
coconut oil, corn oil, cottonseed oil, jojoba oil, jatropa oil,
olive oil etc, and an animal fat can be tallow, lard, chicken oil,
whale sperm, etc. Natural oils and fats offer a few advantages over
mineral oils, such as their high flash points, low emissions of
toxic substances, higher viscosity index, biodegradability,
etc.
[0004] The major constituent of vegetable oils and animal fats is
triglyceride, which is an ester, derived from glycerol and one or
more free fatty acids. The number of carbon atoms and the amount of
saturation and unsaturation in the fatty acid chain define the
properties, such as low temperature behaviour and oxidation
stability of fats and oils. The number of carbon atoms in fatty
acids found in plants and animals ranges from C10 to C30 (most
usual is C12 to C18). The melting point of the fatty acids
increases with an increasing number of carbon atoms in the fatty
acid chain (molecular weight). The extent of saturation and
unsaturation in the fatty acid chains of triglycerides can vary
significantly depending upon the sources of oils and fats. The
saturated fatty acids have a higher melting point as compared to an
unsaturated fatty acid chain. For example, Lauric acid (saturated
and C12) has a melting point of 44.degree. C. and Arachidonic acid
(unsaturated and C20) has a melting point of -50.degree. C., which
means that it is liquid at room temperature. Thus, the higher the
melting point of oils and fats the better is the cold flow property
of the feedstock.
[0005] The oxidation stability of the oils and fats decreases with
increasing amount of unsaturation in the fatty acid chains. For
example, the oxidation stability of a coconut oil is better as
compared to soya oil, as the latter has larger amount of
unsaturation. Oils and fats usually have issues with respect to
their cold temperature properties, oxidative instability and show
poor hydrolytic stability. To overcome these shortcomings,
additives such as cold flow improvers and anti-oxidants,
detergents, dispersants, pour point depressants, emulsifiers etc.
are often added to oils and fats. However, it is known that oils
and fats are not as responsive to the conventional pour point
depressants compared to mineral oil-treatment. Also large dosages
on antioxidants are required in order to acquire oxidation
stability.
[0006] The improvement of the cold flow activity of certain
vegetable oils by adding polyalkyl (meth)acrylates (PAMAs) without
the presence of methyl (meth)acrylate (methyl (meth)acrylate
copolymer is disclosed in U.S. Pat. No. 5,696,066 A (Rohm and Hass
Company)). Another ingredient, which is widely used as cold flow
improver (CFI), are the poly(meth)acrylate and styrene esters as
disclosed in U.S. Pat. No. 5,338,471 A (The Lubrizol Corporation).
Besides this, the use of cold flow improvers based on ethylene
vinyl acetate (EVA) copolymers is disclosed in U.S. Pat. No.
7,276,264 (Clariant GmbH). U.S. Pat. No. 6,565,616 (Clariant GmbH)
discloses an additive for improving the cold flow properties
containing a blend of EVA and copolymers containing maleic
anhydride or alkyl acrylates. EP 0 406 684 B1 (Rohm GmbH) discloses
a flow improver additive containing a mixture of EVA copolymer and
PAMA. U.S. Pat. No. 4,932,980 (Rohm GmbH) discloses flow improvers
based on a graft polymer consisting of 80-20% EVA copolymer as the
backbone and 20-80% alkyl (meth)acrylate as the grafting monomer.
EP 2 305 753 B1 (RohMax Additives GmbH) discloses a composition of
cold flow additives derived from a mixture of PAMA and
EVA-graft-(meth)acrylates which gives a boost in the cold flow
performance of fossil fuel oil and biodiesel fuel oil.
[0007] The use of a variety of natural and synthetic antioxidants
is mentioned improving the oxidation stability of vegetable oils.
H. Sanders Gwin, Jr. have reported the use of anti-oxidants, such
as butylated hydroxyl anisole (BHA), butylated hydrotoluene,
tertiary butyl hydroquinone (TBHQ), tertiary hydrobutrophenone,
ascorbyl palmitate, propyl gallate and alpha-, beta-, or
delta-tocopherol to improve the oxidation stability of one or more
vegetable oils in a dielectric fluid.
[0008] As most of these antioxidant components are solid particles
and contain polar functional groups, the finding of solvents that
will carry higher concentrations of these antioxidants along with
other additives, including CFIs, while being miscible with oils and
fats is a challenge.
[0009] There is a continued need for new formulation containing
concentrated antioxidants and CFIs in solution form. Patent
application publication WO 2009/108851 A1 (Novus International
Inc.) discloses compositions containing at least one phenolic
antioxidant and at least one ethylene amine in aromatic solvents.
Patent application No. US 2007/0197412 A1 (Eastman Chemical Co.)
describes the use of various organic solvents, including
monofunctional alcohols, polyol, esters, ethers, glycol ethers,
ketones and their combinations, to formulate concentrated phenolic
antioxidants and metal-chelating compounds.
[0010] US Patent Application No. 2008/0274921 A1 (Luedeka, Neely
& Graham, P.C.) describes additive compositions for an
environmentally compatible lubricant of PAMA-based PPD and
antioxidants besides a number of other tribologically functional
components. This application also describes the composition of an
environmentally compatible lubricant comprising a vegetable oil
together with the additive composition as described earlier.
[0011] Patent application publication no. WO 02/00815 A2 (Renewable
Lubricants, Inc.) discloses biodegradable vegetable oil
compositions comprising at least on vegetable oil, wherein the
latter comprises at least one genetically modified vegetable oil, a
PPD, which comprises alkylated polystyrene or PAMA, and amine based
antioxidant.
[0012] Based on the objectives mentioned above, a further
improvement of the oxidation stability and the cold flow properties
is an enduring challenge. Preferably, the combination of a cold
flow improver and an antioxidant should provide a synergistic
improvement. At least, no essential decrease in any of these
properties should be achieved.
[0013] The present invention highlights additive formulations
containing cold flow improver and antioxidant in stable, miscible
solution, which offers significant cold flow improvement (pour
point depressant (PPD) activity) and enhanced oxidation stability
of natural oils and fats.
[0014] The presence of EVA-graft-PAMA is essential in order to
maintain homogeneity of the additive formulation, i.e. keeping the
individual components together in one phase. According to the
second finding, the presence of EVA-graft-PAMA provides a boost in
cold flow improvement of the oil.
[0015] There are documents describing vegetable oil compositions
comprising one or more vegetable oils, one or more PPDs, one or
more antioxidants and other additives such as dispersants, friction
modifiers, inhibitors, anti-wear and extreme pressure agents,
detergents etc.
[0016] A first embodiment of the present invention is therefore
directed to an additive composition, comprising: [0017] (A) 35% to
50% by weight of at least one polyalkyl (meth)acrylate polymer
having a number average molecular weight M.sub.n of from 15000 to
75000 g/mol; [0018] (B) 5% to 15% by weight of at least one
ethylene vinyl acetate copolymer comprising units being derived
from at least one alkyl (meth)acrylate having 1 to 30 carbon atoms
in the alkyl residue; [0019] (C) 10% to 20% by weight of a phenolic
type antioxidant; [0020] (D) 10% to 25% by weight of a mixture
stabilizer; and [0021] (E) 10% to 20% by weight of a glycol ether
solvent, wherein the sum of all components (A) to (E) of the
composition add up to 100% by weight.
[0022] According to a preferred aspect of the present invention,
the composition of the present invention preferably comprises at
least one polyalkyl(meth)acrylate polymer having a number average
molecular weight M.sub.n of from 15000 to 75000 g/mol and a
polydispersity M.sub.w/M.sub.n of from 1 to 8. The combination of a
polyalkyl(meth)acrylate polymer having the properties mentioned
above with an ethylene vinyl acetate copolymer provides a
synergistic improvement in oxidation stability and low temperature
flow properties of vegetable oils and animal fats.
[0023] Polyalkyl(meth)acrylate polymers are polymers comprising
units being derived from alkyl(meth)acrylate monomers. The term
(meth)acrylates includes methacrylates and acrylates as well as
mixtures thereof. These monomers are well known in the art. The
alkyl residue of the ester compounds can be linear, cyclic or
branched. The monomers can be used individually or as mixtures of
different alkyl(meth)acrylate monomers to obtain the
polyalkyl(meth)acrylate polymers useful for the present invention.
Usually the polyalkyl(meth)acrylate polymers comprise at least 50%
by weight, preferably at least 70% by weight and more preferably at
least 90% by weight alkyl(meth)acrylate monomers having 7 to 20,
preferably 7 to 15 carbon atoms in the alkyl residue.
[0024] According to a preferred aspect of the present invention,
the polyalkyl(meth)acrylate polymers of component (A) useful for
the present invention may comprise units being derived from one or
more alkyl(meth)acrylate monomers of formula (I)
##STR00001##
wherein [0025] R denotes hydrogen or methyl and [0026] R.sup.1
denotes a linear, branched or cyclic alkyl residue with 1 to 6
carbon atoms, especially 1 to 5 and preferably 1 to 3 carbon
atoms.
[0027] Examples of monomers according to formula (I) are, among
others, (meth)acrylates which derived from saturated alcohols such
as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl
(meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate,
tert-butyl (meth)acrylate, pentyl (meth)acrylate and hexyl
(meth)acrylate; cycloalkyl (meth)acrylates, like cyclopentyl
(meth)acrylate and cyclohexyl (meth)acrylate. Preferably, the
polymer comprises units being derived from methyl methacrylate.
[0028] The polyalkyl(meth)acrylate polymers useful for the present
invention may comprise 0 to 40% by weight, preferably 0.1 to 30% by
weight, in particular 0.5 to 20% by weight of units derived from
one or more alkyl(meth)acrylate monomers of formula (I) based on
the total weight of the polymer.
[0029] The polyalkyl(meth)acrylate polymer may be obtained
preferably by free-radical polymerization. Accordingly the weight
fraction of the units of the polyalkyl(meth)acrylate polymer as
mentioned in the present application is a result of the weight
fractions of corresponding monomers that are used for preparing the
inventive polymer.
[0030] Preferably, the polyalkyl(meth)acrylate polymer comprises
units of one or more alkyl(meth)acrylate monomers of formula
(II)
##STR00002##
wherein [0031] R denotes hydrogen or methyl and [0032] R.sup.2
denotes a linear, branched or cyclic alkyl residue with 7 to 15
carbon atoms.
[0033] Examples of component (II) include
(meth)acrylates that derive from saturated alcohols, such as
2-ethylhexyl (meth)acrylate, heptyl (meth)acrylate,
2-tert-butylheptyl (meth)acrylate, n-octyl (meth)acrylate,
3-isopropylheptyl (meth)acrylate, nonyl (meth)acrylate,
2-propylheptyl (meth)acrylate, decyl (meth)acrylate, undecyl
(meth)acrylate, 5-methylundecyl (meth)acrylate, n-dodecyl
(meth)acrylate, 2-methyldodecyl (meth)acrylate, tridecyl
(meth)acrylate, 5-methyltridecyl (meth)acrylate, n-tetradecyl
(meth)acrylate, pentadecyl (meth)acrylate; (meth)acrylates which
derive from unsaturated alcohols, for example oleyl (meth)acrylate;
cycloalkyl (meth)acrylates such as cyclohexyl (meth)acrylate having
a ring substituent, like tert-butylcyclohexyl (meth)acrylate and
trimethylcyclohexyl (meth)acrylate, bornyl (meth)acrylate and
isobornyl (meth)acrylate.
[0034] According to a preferred aspect of the present invention,
the polymer comprises preferably about 40 to 99% by weight, more
preferably about 60 to 95% by weight of units derived from monomers
according to formula (II).
[0035] Furthermore, the polyalkyl(meth)acrylate polymers useful for
the present invention may comprise units being derived from one or
more alkyl(meth)acrylate monomers of formula (III)
##STR00003##
wherein [0036] R denotes hydrogen or methyl and [0037] R.sup.3
denotes a linear, branched or cyclic alkyl residue with 16 to 30
carbon atoms.
[0038] Examples of component (III) include (meth)acrylates which
derive from saturated alcohols, such as hexadecyl (meth)acrylate,
2-methylhexadecyl (meth)acrylate, heptadecyl (meth)acrylate,
5-isopropylheptadecyl (meth)acrylate, 4-tert-butyloctadecyl
(meth)acrylate, 5-ethyloctadecyl (meth)acrylate,
3-isopropyloctadecyl (meth)acrylate, octadecyl (meth)acrylate,
nonadecyl (meth)acrylate, eicosyl (meth)acrylate, cetyleicosyl
(meth)acrylate, stearyleicosyl (meth)acrylate, docosyl
(meth)acrylate and/or eicosyltetratriacontyl (meth)acrylate;
cycloalkyl (meth)acrylates such as
2,4,5-tri-t-butyl-3-vinylcyclohexyl (meth)acrylate,
2,3,4,5-tetra-t-butylcyclohexyl (meth)acrylate.
[0039] The polyalkyl(meth)acrylate polymers useful for the present
invention may comprise 0.1 to 40% by weight, in particular 0.5 to
35% by weight of units derived from one or more alkyl(meth)acrylate
monomers of formula (III) based on the total weight of the
polymer.
[0040] The ester compounds with a long-chain alcohol residue,
especially monomers according to formulae (II) and (III), can be
obtained, for example, by reacting (meth)acrylates and/or the
corresponding acids with long chain fatty alcohols, where in
general a mixture of esters such as (meth)acrylates with different
long chain alcohol residues results. These fatty alcohols include,
among others, Oxo Alcohol.RTM. 7911 and Oxo Alcohol.RTM. 7900, Oxo
Alcohol.RTM. 1100 (Monsanto); Alphanol.RTM. 79 (ICI); Nafol.RTM.
1620, Alfol.RTM. 610 and Alfol.RTM. 810 (Sasol); Epal.RTM. 610 and
Epal.RTM. 810 (Ethyl Corporation); Linevol.RTM. 79, Linevol.RTM.
911 and Dobanol.RTM. 25L (Shell AG); Lial 125 (Sasol); Dehydad.RTM.
and Dehydad.RTM. and Lorol.RTM. (Cognis).
[0041] The polymer may contain units derived from comonomers as an
optional component.
[0042] These comonomers include hydroxyalkyl (meth)acrylates like
3-hydroxypropyl (meth)acrylate, 3,4-dihydroxybutyl (meth)acrylate,
2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate,
2,5-dimethyl-1,6-hexanediol (meth)acrylate, 1,10-decanediol
(meth)acrylate;
aminoalkyl (meth)acrylates and aminoalkyl (meth)acrylamides like
N-(3-dimethyl-aminopropyl)methacrylamide, 3-diethylaminopentyl
(meth)acrylate, 3-dibutyl-aminohexadecyl (meth)acrylate; nitriles
of (meth)acrylic acid and other nitrogen-containing (meth)acrylates
like N-(methacryloyloxyethyl)diisobutylketimine,
N-(methacryloyloxyethyl)dihexadecyl-ketimine,
(meth)acryloylamidoacetonitrile,
2-methacryloyloxyethylmethylcyanamide, cyanomethyl (meth)acrylate;
aryl (meth)acrylates like benzyl (meth)acrylate or phenyl
(meth)acrylate, where the acryl residue in each case can be
unsubstituted or substituted up to four times; carbonyl-containing
(meth)acrylates like 2-carboxyethyl (meth)acrylate, carboxymethyl
(meth)acrylate, oxazolidinylethyl (meth)acrylate,
N-methyacryloyloxy)-formamide, acetonyl (meth)acrylate,
N-methacryloylmorpholine, N-methacryloyl-2-pyrrolidinone,
N-(2-methyacryloxyoxyethyl)-2-pyrrolidinone,
N-(3-methacryloyloxy-propyl)-2-pyrrolidinone,
N-(2-methyacryloyloxypentadecyl(-2-pyrrolidinone,
N-(3-methacryloyloxyheptadecyl-2-pyrrolidinone; (meth)acrylates of
ether alcohols like tetrahydrofurfuryl (meth)acrylate,
methoxyethoxyethyl (meth)acrylate, 1-butoxypropyl (meth)acrylate,
cyclohexyloxyethyl (meth)acrylate, propoxyethoxyethyl
(meth)acrylate, benzyloxyethyl (meth)acrylate, furfuryl
(meth)acrylate, 2-butoxyethyl (meth)acrylate,
2-ethoxy-2-ethoxyethyl (meth)acrylate, 2-methoxy-2-ethoxypropyl
(meth)acrylate, ethoxylated (meth)acrylates, 1-ethoxybutyl
(meth)acrylate, methoxyethyl (meth)acrylate,
2-ethoxy-2-ethoxy-2-ethoxyethyl (meth)acrylate, esters of
(meth)acrylic acid and methoxy polyethylene glycols;
(meth)acrylates of halogenated alcohols like 2,3-dibromopropyl
(meth)acrylate, 4-bromophenyl (meth)acrylate, 1,3-dichloro-2-propyl
(meth)acrylate, 2-bromoethyl (meth)acrylate, 2-iodoethyl
(meth)acrylate, chloromethyl (meth)acrylate; oxiranyl
(meth)acrylate like 2,3-epoxybutyl (meth)acrylate, 3,4-epoxybutyl
(meth)acrylate, 10,11 epoxyundecyl (meth)acrylate,
2,3-epoxycyclohexyl (meth)acrylate, oxiranyl (meth)acrylates such
as 10,11-epoxyhexadecyl (meth)acrylate, glycidyl (meth)acrylate;
phosphorus-, boron- and/or silicon-containing (meth)acrylates like
2-(dimethyl-phosphato)propyl (meth)acrylate,
2-(ethylphosphito)propyl (meth)acrylate, 2-dimethylphosphinomethyl
(meth)acrylate, dimethylphosphonoethyl (meth)acrylate,
diethylmethacryloyl phosphonate, dipropylmethacryloyl phosphate,
2-(dibutylphosphono)ethyl (meth)acrylate,
2,3-butylenemethacryloylethyl borate,
methyldiethoxymethacryloylethoxysiliane, diethylphosphatoethyl
(meth)acrylate; sulfur-containing (meth)acrylates like
ethylsulfinylethyl (meth)acrylate, 4-thio-cyanatobutyl
(meth)acrylate, ethylsulfonylethyl (meth)acrylate,
thiocyanatomethyl (meth)acrylate, methylsulfinylmethyl
(meth)acrylate, bis(methacryloyloxyethyl) sulfide; heterocyclic
(meth)acrylates like 2-(1-imidazolyl)ethyl (meth)acrylate,
2-(4-morpholinyl)ethyl (meth)acrylate and
1-(2-methacryloyloxyethyl)-2-pyrrolidone; maleic acid and maleic
acid derivatives such as mono- and diesters of maleic acid, maleic
anhydride, methylmaleic anhydride, maleinimide, methylmaleinimide;
fumaric acid and fumaric acid derivatives such as, for example,
mono- and diesters of fumaric acid; vinyl halides such as, for
example, vinyl chloride, vinyl fluoride, vinylidene chloride and
vinylidene fluoride; vinyl esters like vinyl acetate; vinyl
monomers containing aromatic groups like styrene, substituted
styrenes with an alkyl substituent in the side chain, such as
alpha-methylstyrene and alpha-ethylstyrene, substituted styrenes
with an alkyl substituent on the ring such as vinyltoluene and
p-methylstyrene, halogenated styrenes such as monochlorostyrenes,
dichlorostyrenes, tribromostyrenes and tetrabromostyrenes;
heterocyclic vinyl compounds like 2-vinylpyridine, 3-vinylpyridine,
2-methyl-5-vinylpyridine, 3-ethyl-4-vinylpyridine,
2,3-dimethyl-5-vinylpyridine, vinylpyrimidine, vinylpiperidine,
9-vinylcarbazole, 3-vinylcarbazole, 4-vinylcarbazole,
1-vinylimidazole, 2-methyl-1-vinylimidazole, N-vinylpyrrolidone,
2-vinylpyrrolidone, N-vinylpyrrolidine, 3-vinylpyrrolidine,
N-vinylcaprolactam, N-vinylbutyrolactam, vinyloxolane, vinylfuran,
vinylthiophene, vinylthiolane, vinylthiazoles and hydrogenated
vinylthiazoles, vinyloxazoles and hydrogenated vinyloxazoles; vinyl
and isoprenyl ethers; methacrylic acid and acrylic acid.
[0043] The comonomers and the ester monomers of the formulae (I),
(II) and (III) can each be used individually or as mixtures.
[0044] The proportion of comonomers can be varied depending on the
use and property profile of the polymer. In general, this
proportion may be in the range from 0 to 60% by weight, preferably
from 0.01 to 20% by weight and more preferably from 0.1 to 10% by
weight. Owing to the combustion properties and for ecological
reasons, the proportion of the monomers which comprise aromatic
groups, heteroaromatic groups, nitrogen-containing groups,
phosphorus-containing groups and sulphur-containing groups should
be minimized. The proportion of these monomers can therefore be
restricted to 1% by weight, in particular 0.5% by weight and
preferably 0.01% by weight.
[0045] Preferably, the polyalkyl(meth)acrylate polymer comprises
units derived from hydroxyl-containing monomers and/or
(meth)acrylates of ether alcohols. According to a preferred aspect
of the present invention, the polyalkyl(meth)acrylate polymer
preferably comprises 0.1 to 40% by weight, especially 1 to 20% by
weight and more preferably 2 to 10% by weight of
hydroxyl-containing monomer and/or (meth)acrylates of ether
alcohols based on the weight of the polymer. The
hydroxyl-containing monomers include hydroxyalkyl (meth)acrylates
and vinyl alcohols. These monomers have been disclosed in detail
above.
[0046] The polyalkyl(meth)acrylate polymers of component (A)
preferably have a number average molecular weight M.sub.n in the
range of 15000 to 75000 g/mol
[0047] The polydispersity M.sub.w/M.sub.n of the
polyalkyl(meth)acrylate polymers preferably is in the range from of
1 to 8, especially from 1.05 to 6.0, more preferably from 1.1 to
5.0 and most preferably from 1.1 to 4. The weight average molecular
weight M.sub.w, the number average molecular weight M.sub.n and the
polydispersity M.sub.w/M.sub.n can be determined by GPC using a
methyl methacrylate polymer as standard.
[0048] The architecture of the polyalkyl(meth)acrylate polymers is
not critical for many applications and properties. Accordingly,
these polymers may be random copolymers, gradient copolymers, block
copolymers and/or graft copolymers. Block copolymers and gradient
copolymers can be obtained, for example, by altering the monomer
composition discontinuously during the chain growth.
[0049] According to a preferred embodiment, the present composition
comprises at least one ethylene vinyl acetate copolymer comprising
units being derived from at least one alkyl (meth)acrylate having 1
to 30 carbon atoms in the alkyl residue as component (B).
[0050] Polymers comprising units being derived from ethylene, vinyl
acetate and at least one alkyl (meth)acrylate having 1 to 30 carbon
atoms in the alkyl residue can be obtained by the polymerisation of
corresponding monomer compositions. Ethylene and vinyl acetate are
commercially available from a number of suppliers. Alkyl
(meth)acrylates having 1 to 30 carbon atoms in the alkyl residue
are described below and above and reference is made thereto.
[0051] These ethylene vinyl acetate copolymers may contain 1 to 60%
by weight, particularly 5 to 40% by weight, preferably 10 to 20% by
weight of units being derived from ethylene based on the total of
the repeating units. Particular preference is given to ethylene
vinyl acetate copolymers containing preferably 0.5 to 60% by
weight, especially 2 to 40% by weight or 3 to 40% by weight and
more preferably 5 to 10% by weight of vinyl acetate based on the
total of the repeating units.
[0052] Preferably, the amount of alkyl (meth)acrylates having 1 to
30 carbon atoms in the alkyl residue is in the range of from 10% by
weight to 90% by weight, especially in the range of from 30 to 80%
by weight and more preferably in the range of from 60 to 80% by
weight based on the total of the repeating units.
[0053] According to a special embodiment of the present invention,
the ethylene vinyl acetate copolymers preferably comprise from 30
to 90% by weight, more preferably from 60 to 80% by weight, of
units being derived from at least one alkyl (meth)acrylate having 7
to 15 carbon atoms in the alkyl residue.
[0054] Preferably, the molar ratio of ethylene to vinyl acetate of
the ethylene vinyl acetate copolymer could be in the range of 100:1
to 1:2, more preferably in the range of 20:1 to 2:1, especially
preferably 10:1 to 3:1. The molar ratio of alkyl (meth)acrylates
having 1 to 30 carbon atoms in the alkyl residue to vinyl acetate
of the ethylene vinyl acetate copolymer is preferably in the range
of 50:1 to 1:2, more preferably in the range of 10:1 to 1:1,
especially preferably 5:1 to 2:1. Particularly, the molar ratio of
ethylene to alkyl (meth)acrylates having 1 to 30 carbon atoms in
the alkyl residue of the ethylene vinyl acetate copolymer is
preferably in the range of 10:1 to 1:20, more preferably in the
range of 2:1 to 1:10, especially preferably 1:1 to 1:5.
[0055] In addition to the monomers mentioned above and below, the
ethylene vinyl acetate copolymer may contain further comonomers.
These monomers are mentioned above and below and reference is made
thereto. Especially preferred are vinyl esters and olefins.
Suitable vinyl esters derive from fatty acids having linear or
branched alkyl groups having 2 to 30 carbon atoms. Examples include
vinyl propionate, vinyl butyrate, vinyl hexanoate, vinyl
heptanoate, vinyl octanoate, vinyl laurate and vinyl stearate, and
also esters of vinyl alcohol based on branched fatty acids, such as
vinyl isobutyrate, vinyl pivalate, vinyl 2-ethylhexanoate, vinyl
isononanoate, vinyl neononanoate, vinyl neodecanoate and vinyl
neoundecanoate. Suitable olefins include propene, butene,
isobutylene, hexene, 4-methylpentene, octene, diisobutylene and/or
norbornene.
[0056] Particularly, ethylene vinyl acetate copolymer may comprise
from 0 to 20% by weight and more preferably from 1 to 10% by weight
of units being derived from comonomers.
[0057] The architecture of the ethylene vinyl acetate copolymers is
not critical for many applications and properties. Accordingly, the
ester-comprising polymers may be random copolymers, gradient
copolymers, block copolymers and/or graft copolymers.
[0058] According to a special aspect of the present invention,
ethylene vinyl acetate copolymers is a graft copolymer having an
ethylene vinyl acetate copolymer as graft base and an alkyl
(meth)acrylate having 1 to 30 carbon atoms in the alkyl residue as
graft layer. Preferably, the weight ratio of graft base to graft
layer is in the range of from 1:1 to 1:20 more preferably 1:2 to
1:10.
[0059] The polydispersity M.sub.w/M.sub.n of the ethylene vinyl
acetate copolymers may be in the range from of 1 to 8, preferably
from 1.05 to 6.0 and most preferably from 1.2 to 5.0. The weight
average molecular weight M.sub.w, the number average molecular
weight M.sub.n and the polydispersity M.sub.w/M.sub.n can be
determined by GPC using a methyl methacrylate polymer as
standard.
[0060] The ethylene vinyl acetate copolymers to be used in
accordance with the invention can be prepared by the free radical
polymerization method mentioned above and reference is made
thereto. Preferably, the ethylene vinyl acetate copolymers can be
manufactured according to the method described in EP-A 406684 (Rohm
GmbH).
[0061] According to a preferred aspect of the present invention,
the ethylene vinyl acetate copolymer is a graft copolymer having an
ethylene vinyl acetate copolymer as graft base. The ethylene vinyl
acetate copolymer useful as graft base preferably have a number
average molecular weight M.sub.n in the range of 1000 to 100 000
g/mol, especially in the range of 5000 to 80 000 g/mol and more
preferably in the range of 10 000 to 50 000 g/mol.
[0062] The preparation of the polyalkyl(meth)acrylate polymers and
the ethylene vinyl acetate copolymer comprising units being derived
from at least one alkyl (meth)acrylate from the above-described
monomers is known per se. Thus, these polymers can be obtained in
particular by free-radical polymerization and related processes,
for example ATRP (=Atom Transfer Radical Polymerization), RAFT
(=Reversible Addition Fragmentation Chain Transfer) or NMP
processes (nitroxide-mediated polymerization). In addition thereto,
these polymers are also available by anionic polymerisation.
[0063] Customary free-radical polymerization is described, inter
alia, in Ullmann's Encyclopedia of Industrial Chemistry, Sixth
Edition. In general, a polymerization initiator is used for this
purpose. The usable initiators include the azo initiators widely
known in the technical field, such as 2,2'-azo-bis-isobutyronitrile
(AIBN), 2,2'-azo-bis-(2-methylbutyronitrile) (AMBN) and
1,1-azobiscyclohexanecarbonitrile, and also peroxy compounds such
as methyl ethyl ketone peroxide, acetylacetone peroxide, dilauryl
peroxide, tert-butyl peroxypivalate, tert-butyl peroxy-2-ethyl
hexanoate, tert-amyl peroxy-2-ethyl hexanoate, ketone peroxide,
tert-butyl peroctoate, methyl isobutyl ketone peroxide,
cyclohexanone peroxide, dibenzoyl peroxide,
tert-butyl-peroxybenzoate, tert-butyl-peroxyisopropylcarbonate,
2,5-bis(2-ethylhexanoyl-peroxy)-2,5-dimethylhexane,
tert-butyl-peroxy-2-ethylhexanoate,
tert-butyl-peroxy-3,5,5-trimethylhexanoate, dicumyl peroxide,
1,1-bis(tert-butyl-peroxy)cyclohexane,
1,1-bis(tert-butyl-peroxy)-3,3,5-trimethylcyclohexane, cumyl
hydroperoxide, tert-butyl-hydroperoxide,
bis(4-tert-butylcyclohexyl) peroxydicarbonate, mixtures of two or
more of the aforementioned compounds with one another, and mixtures
of the aforementioned compounds with compounds which have not been
mentioned but can likewise form free radicals. Furthermore a chain
transfer agents can be used. Suitable chain transfer agents are in
particular oil-soluble mercaptans, for example dodecyl mercaptan or
2-mercaptoethanol, or else chain transfer agents from the class of
the terpenes, for example terpineols.
[0064] Preferably, the polymers can be achieved by using high
amounts of initiator and low amounts of chain transfer agents.
Especially, the mixture to obtain the polyalkyl(meth)acrylate
polymer useful for the present invention may comprise 1 to 15% by
weight, preferably 2 to 10% by weight and more preferable 4 to 8%
by weight initiator based on the amount of monomers. The amount of
chain transfer agents can be used in an amount of 0 to 2% by
weight, preferably 0.01 to 1% by weight and more preferable 0.02 to
0.1% by weight based on the amount of monomers.
[0065] The ATRP process is known per se. It is assumed that it is a
"living" free-radical polymerization, without any intention that
this should restrict the description of the mechanism. In these
processes, a transition metal compound is reacted with a compound
which has a transferable atom group. This transfers the
transferable atom group to the transition metal compound, which
oxidizes the metal. This reaction forms a radical which adds onto
ethylenic groups. However, the transfer of the atom group to the
transition metal compound is reversible, so that the atom group is
transferred back to the growing polymer chain, which forms a
controlled polymerization system. The structure of the polymer, the
molecular weight and the molecular weight distribution can be
controlled correspondingly. This reaction is described, for
example, by J S. Wang, et al., J. Am. Chem. Soc., vol. 117, p.
5614-5615 (1995), by Matyjaszewski, Macromolecules, vol. 28, p.
7901-7910 (1995). In addition, the patent applications WO 96/30421,
WO 97/47661, WO 97/18247, WO 98/40415 and WO 99/10387 disclose
variants of the ATRP explained above.
[0066] Preferably, catalytic chain transfer processes using cobalt
(II) chelates complex can be used to prepare the polymers useful
for the present invention as disclosed in U.S. Pat. No. 4,694,054
(Du Pont Co) or U.S. Pat. No. 4,526,945 (SCM Co).
[0067] In addition, the polymers may be obtained, for example, also
via RAFT methods. This process is presented in detail, for example,
in WO 98/01478 and WO 2004/083169, to which reference is made
explicitly for the purposes of disclosure.
[0068] In addition, the polymers are also obtainable by NMP
processes (nitroxide-mediated polymerization), which is described,
inter alia, in U.S. Pat. No. 4,581,429.
[0069] These methods are described comprehensively, in particular
with further references, inter alia, in K. Matyjazewski, T. P.
Davis, Handbook of Radical Polymerization, Wiley Interscience,
Hoboken 2002, to which reference is made explicitly for the
purposes of disclosure.
[0070] The anionic polymerisation is well known in the art and
described, inter alia, in Ullmann's Encyclopedia of Industrial
Chemistry, Sixth Edition. According to a preferred aspect of the
present invention, the polyalkyl(meth)acrylate polymer can be
obtained according to a method described in U.S. Pat. No. 4,056,559
(Rohm & Haas Co) Particularly, potassium methoxide solution can
be used as initiator.
[0071] The polymerization may be carried out at standard pressure,
reduced pressure or elevated pressure. The polymerization
temperature too is uncritical. However, it is generally in the
range of -200.degree. C. to 200.degree. C., especially 0.degree. C.
to 190.degree. C., preferably 60.degree. C. to 180.degree. C. and
more preferably 120.degree. C. to 170.degree. C. Higher
temperatures are especially preferred in free radical
polymerizations using high amounts of initiators.
[0072] The polymerization may be carried out with or without
solvent. The term solvent is to be understood here in a broad
sense.
[0073] The polymerization is preferably carried out in a nonpolar
solvent. These include hydrocarbon solvents, for example aromatic
solvents such as toluene, benzene and xylene, saturated
hydrocarbons, for example cyclohexane, heptane, octane, nonane,
decane, dodecane, which may also be present in branched form. These
solvents may be used individually and as a mixture. Particularly
preferred solvents are mineral oils, diesel fuels of mineral
origin, naphthenic solvents, natural vegetable and animal oils,
biodiesel fuels and synthetic oils (e.g. ester oils such as dinonyl
adipate), and also mixtures thereof. Among these, very particular
preference is given to mineral oils, mineral diesel fuels and
naphthenic solvent (e.g. commercially available Shellsol.RTM. A150,
Solvesso.RTM. A150).
[0074] In addition to the ethylene vinyl acetate copolymer
comprising units being derived from at least one alkyl
(meth)acrylate having 1 to 30 carbon atoms in the alkyl residue as
described above, the composition of the present invention may
preferably comprise at least one polyalkyl(meth)acrylate polymer.
As mentioned above, also the polyalkyl(meth)acrylate polymer may
comprise units being derived from ethylene and vinyl acetate as
comonomers. However, the ethylene vinyl acetate copolymer differs
from the polyalkyl(meth)acrylate copolymer. Especially, the amounts
of ethylene and/or vinyl acetate in the ethylene vinyl acetate
copolymer are higher than in the polyalkyl(meth)acrylate polymer.
Therefore the present composition may preferably comprise at least
two polymers being different in their ethylene and/or vinyl acetate
proportion.
[0075] The weight ratio of both polymers may be in a wide range.
Preferably, the weight ratio of the polyalkyl(meth)acrylate polymer
having a number average molecular weight M.sub.n of from 15000 to
75000 g/mol and a polydispersity M.sub.w/M.sub.n of from 1 to 8 to
the ethylene vinyl acetate copolymer comprising units being derived
from at least one alkyl (meth)acrylate having 1 to 30 carbon atoms
in the alkyl residue is in the range of from 40:1 to 1:10,
particularly 20:1 to 1:2, especially 15:1 to 1:1, more preferably
10:1 to 3:1 and most preferably 6:1 to 5:1.
[0076] The inventive composition further comprises at least one
antioxidant as component (C). The antioxidant used in the present
invention is in the general class known as free radical inhibitors
and/or antioxidants. More specifically the antioxidants used are
well known as disclosed in the documents mentioned above.
[0077] Preferred antioxidants useful for the present invention are
disclosed in US patent application publication no. 2004/0139649, US
2006/0219979 and US 2009/094887A1 and international publication WO
2009/108747 A1.
[0078] The antioxidants are generally commercially available. For
more details it is herein referred to known prior art, in
particular to Rompp-Lexikon Chemie; Editor: J. Falbe, M. Regitz;
Stuttgart, N.Y.; 10. version (1996); keyword "antioxidants" and the
at this site cited literature references.
[0079] Antioxidants include e.g. aromatic compounds and/or nitrogen
containing compounds.
[0080] Organic nitrogen compounds being useful as antioxidant are
known in themselves. Besides one or more nitrogen atoms, they
contain alkyl, cycloalkyl or aryl groups, and the nitrogen atom may
also be a member of a cyclic group.
[0081] Preferably, nitrogen containing compounds include
amine-containing antioxidant components. Examples include
naphthylamine derivative, diphenylamine derivative, p-phenylene
diamine derivative, and quinoline derivative as mentioned e.g. in
CN 101353601 A, nitro-aromatics, e.g. nitro benzene,
di-nitrobenzene, nitro-toluene, nitro-napthalene, and
di-nitro-napthalene and alkyl nitro benzenes and poly aromatics as
mentioned e.g. in WO 2008/056203 A2 and aliphatic amine as
described e.g. in WO 2009/016400 A1.
[0082] Preferred antioxidants comprise amines, such as
thiodiphenylamine and phenothiazine; and/or p-phenylene diamines,
such as N,N'-diphenyl-p-phenylene diamine,
N,N'-di-2-naphthyl-p-phenylene diamine, N,N'-di-p-tolyl-p-phenylene
diamine, N-1,3-dimethylbutyl-N'-phenyl-p-phenylene diamine and
N-1,4-dimethylpentyl-N'-phenyl-p-phenylene diamine.
[0083] In a very preferred embodiment of the invention, the
antioxidant is an aromatic compound. These aromatic compounds
comprise phenolic compounds; especially sterically hindered
phenols, such as 2,4-di-t-butylhydroxytoluene (BHT),
2,4-dimethyl-6-tert-butylphenol or 2,6-ditert-butyl-4-methylphenol;
tocopherol-compounds, preferably alpha-tocopherol; and/or
hydroquinone ethers, such as hydroquinone monomethylether,
2-tert-Butyl-4-hydroxyanisole and
3-tert-butyl-4-hydroxyanisole.
[0084] Especially preferred phenolic compounds have 2 or more
hydroxyl groups such as dihydroxybenzenes, preferably hydroquinone
or derivatives thereof, such as alkyl hydroquinones, e.g.
tert-butylhydroquinone (TBHQ), 2,6-di-tert-butylhydroquinone
(DTBHQ), 2,5-di-tert-butylhydroquinone or pyrocatechol or alkyl
pyrocatechols, e.g. di-tert-butylbrenzcatechine.
[0085] Furthermore, phenolic compounds having 3 or more hydroxyl
groups are preferred. These compounds include e.g. propyl gallate
and pyrogallol.
[0086] Regarding the antioxidants mentioned, phenolic compounds are
especially preferred.
[0087] The antioxidants can be used individually or as a mixture.
Surprising results could be achieved with mixtures comprising
phenolic compounds having at least two hydroxyl groups such as
hydroquinones, propyl gallate and pyrogallol; and phenolic
compounds having exactly one hydroxyl groups such as hydroquinone
ethers, sterically hindered phenols, such as
2,4-di-tert-butylhydroxytoluene (BHT),
2,4-dimethyl-6-tert-butylphenol or
2,6-di-tert-butyl-4-methylphenol; and/or tocopherol-compounds,
preferably alpha-tocopherol. According to a very preferred
embodiment, the mixture may preferably comprise phenolic compounds
having at least three hydroxyl groups such as propyl gallate and
pyrogallol; and phenolic compounds having exactly two hydroxyl
groups such as hydroquinone or derivatives thereof.
[0088] If more than one antioxidant is used, the two antioxidants
can preferably be at a weight ratio of in the range of about 20:1
to 1:20, especially more preferably 10:1 to 1:10, more preferably
5:1 to 1:5. Depending on the desired characteristics of the
biodiesel, one skilled in the art, in view of the present
disclosure, would be able to select appropriate concentrations and
ratios of antioxidants.
[0089] According to a preferred aspect of the present invention,
the composition comprises a mixture stabilizer as component (D),
preferably phenolic compounds having exactly one hydroxyl groups
such as hydroquinone ethers, sterically hindered phenols, such as
2,4-di-tert-butylhydroxytoluene (BHT),
2,4-dimethyl-6-tert-butylphenol or
2,6-di-tert-butyl-4-methylphenol; and/or tocopherol-compounds,
preferably alpha-tocopherol. Preferably sterically hindered
phenols, such as 2,4-di-tert-butylhydroxytoluene (BHT),
2,4-dimethyl-6-tert-butylphenol or 2,6-di-tert-butyl-4-methylphenol
can be used as mixture stabilizer with
2,4-di-tert-butylhydroxytoluene being more preferred.
[0090] Preferably, the composition according to the present
invention can be prepared by mixing the components mentioned above.
Solvents can be used for accomplishing the mixing. Preferred
solvents are polar organic solvents, especially ethers and esters.
Preferably, ethers and esters comprise glycol groups.
[0091] Preferred solvents of component (E) include ethers, more
preferably glycol ethers such as ethylene glycol monomethyl ether
(2-methoxyethanol), ethylene glycol monoethyl ether
(2-ethoxyethanol), ethylene glycol monopropyl ether
(2-propoxyethanol), ethylene glycol monoisopropyl ether
(2-isopropoxyethanol), ethylene glycol monobutyl ether
(2-butoxyethanol), ethylene glycol monophenyl ether
(2-phenoxyethanol), ethylene glycol monobenzyl ether
(2-benzyloxyethanol), diethylene glycol monomethyl ether
(2-(2-methoxyethoxyl)ethanol), diethylene glycol monoethyl ether
(2-(2-ethoxyethoxyl)ethanol, diethylene glycol mono-n-butyl ether
(2-(2-butoxyethoxyl)ethanol), ethylene glycol dimethyl ether
(dimethoxyethane), ethylene glycol diethyl ether (diethoxyethane)
and ethylene glycol dibutyl ether (dibutoxyethane). Regarding the
ethers diethylene glycol solvents are preferred, especially
diethylene glycol monobutyl ether.
[0092] Preferred esters having glycol groups include ethylene
glycol methyl ether acetate (2-methoxyethyl acetate), ethylene
glycol monoethyl ether acetate (2-ethoxyethyl acetate) and ethylene
glycol monobutyl ether acetate (2-butoxyethyl acetate).
[0093] The mixture achieved can be used as an additive
composition.
[0094] Preferably, an additive composition comprises at most 70% by
weight, especially at most 50% by weight and more preferably at
most 30% by weight of solvent. Preferably, an additive composition
comprises at least 2% by weight, especially at least 5% by weight
and more preferably at least 10% by weight of mixture stabilizer.
Preferably, an additive composition comprises at least 2% by
weight, especially at least 5% by weight and more preferably at
least 10% by weight of mixture antioxidant. Preferably, an additive
composition comprises at least 10% by weight, especially at least
20% by weight and more preferably at least 25% by weight of cold
flow improver. According to a special aspect of the present
invention, the cold flow improver comprises a mixture of more
preferably a mixture of at least one polyalkyl(meth)acrylate
polymer having a number average molecular weight M.sub.n of from
15000 to 75000 g/mol and a polydispersity M.sub.w/M.sub.n of from 1
to 8 and at least one ethylene vinyl acetate copolymer comprising
units being derived from at least one alkyl (meth)acrylate having 1
to 30 carbon atoms in the alkyl residue. The compositions provide
homogenous miscible mixture which can improve both cold flow and
oxidation stability of vegetable oils and animal fats.
[0095] According to a preferred embodiment, the mixture stabilizer
and the cold flow improver are mixed as a first solution, while the
antioxidant is solved in a solvent to form a second solution. The
first and the second solution can be mixed, preferably at a
temperature in the range of 40 to 100.degree. C., more preferably
at a temperature in the range of 60 to 80.degree. C. to form a
homogenous additive mixture which can improve both cold flow and
oxidation stability of vegetable oils and animal fats. The ethylene
vinyl acetate copolymer comprising units being derived from at
least one alkyl (meth)acrylate having 1 to 30 carbon atoms in the
alkyl residue can be added to the first and/or second solution.
[0096] Surprisingly an additive composition comprising a mixture of
at least one polyalkyl(meth)acrylate polymer having a number
average molecular weight M.sub.n of from 15000 to 75000 g/mol and a
polydispersity M.sub.w/M.sub.n of from 1 to 8 and at least one
ethylene vinyl acetate copolymer comprising units being derived
from at least one alkyl (meth)acrylate having 1 to 30 carbon atoms
in the alkyl residue provides a stable liquid composition. The
stability and miscibility can be improved by using a mixture
stabilizer and/or a solvent.
[0097] Examples of vegetable oils which can be used in accordance
with the invention are palm oil, rapeseed oil, coriander oil, soya
oil, cottonseed oil, sunflower oil, castor oil, olive oil,
groundnut oil, corn oil, almond oil, palm kernel oil, coconut oil,
mustard seed oil, jojoba oil, jatropa oil, olive oil etc. Examples
of animal fats which can be used in accordance with the invention
are oils which are derived from animal tallow, especially beef
tallow, bone oil, fish oils, lard, chicken oil, whale sperm, etc.
and used cooking oils. Further examples include oils which derive
from cereal, wheat, jute, sesame, rice husks, jatropha, arachis oil
and linseed oil.
[0098] The common methods to evaluate the cold flow quality are
pour point (PP) tests as mentioned in ASTM D97. Oxidation stability
of oils and fats is normally evaluated via Rancimat test (EN
14112), measured at 110.degree. C. In this test, a purified air
stream is fed through the sample to induce the formation of
volatile acids formed from the oxidation process. These volatile
acids are then distilled into a measurement vessel containing
deionised water, in which the conductivity of the solution is
measured. The end of induction period is measured as the
conductivity increases. Typical induction periods for rapeseed oil
are 5 to 7 h and 1 to 2 h for sunflower oil. A few examples of
antioxidants include BHA (butylated hydroxy anisole), BHT
(butylated hydroxy toluene), TBHQ (tertiary butylated hydroxy
quinone) etc., which are successfully used to improve the cold flow
behaviour of vegetable oils and animal fats.
[0099] The use of antioxidants and ethylene vinyl acetate copolymer
comprising units being derived from at least one alkyl
(meth)acrylate having 1 to 30 carbon atoms in the alkyl residue in
a concentration of 0.01 to 4% by weight, preferably 0.05 to 2% by
weight, as a flow improver in fuel compositions which comprise
vegetable oils and/or animal fats accordingly provides lubricant
compositions with exceptional properties, especially a high
oxidation stability and good cold flow properties.
[0100] The invention will be illustrated in detail hereinafter with
reference to examples and comparative examples, without any
intention that this should impose a restriction. Unless otherwise
specified, the percentages are weight percent.
EXAMPLES
[0101] The following different types of vegetable oils were used in
the examples:
TABLE-US-00001 Pour Point Rancimat induction period Oil/Fat (PP)
(IP) Sunflower oil -15.degree. C. ~1.2 hours High oleic sunflower
oil -18.degree. C. ~6.5 hours Soybean oil -9.degree. C. ~4.5 hours
Canola oil-II -18.degree. C. ~8.5 hours High oleic canola oil
-18.degree. C. ~15 hours
General Method to Prepare the CFI and the Additive Containing CFI
and Antioxidant
Example 1
Preparation of PAMA-I
[0102] PAMA-I, which has a number average molecular weight
(M.sub.n) in the range of 35000 g/mol to 75000 g/mol, can be
prepared by the following method:
A reaction vessel was charged with 10.24 g stearyl methacrylate
(SMA), 52.7 g dodecyl pentadecyl methacrylate (DPMA), 7 g methyl
methacrylate (MMA), and 0.2 g n-dodecyl mercaptan. The resulting
mixture was stirred under nitrogen inert conditions and heated up
to a reaction temperature of 115.degree. C. An initiator mixture
containing 0.18 g tert-butyl-per-2-ethyl-hexanoate and 7.8 g
diisononyladipate was separately prepared. The initiator mixture
was fed to the reaction mixture for 150 minutes in two steps.
Step-1: 2.0 gram of initiator mixture over 90 minutes at
115.degree. C., step-2: 3.35 gram of initiator mix over 60 minutes
at 115.degree. C. Later, 0.24 g of tert-butyl-per-2-ethyl-hexanoate
was added in the remaining initiator mix and was fed for 60 minutes
at 105.degree. C. The reaction was held for another 30 minutes at
105.degree. C. Thereafter, 22.2 g of rapeseed oil was added to the
product in order to bring it to a desired dilution.
Example 2
Preparation of PAMA-II
[0103] PAMA-II, which has a number average molecular weight
(M.sub.e) in the range of 35000 g/mol to 75000 g/mol, can be
prepared by the following method:
A reaction vessel was charged with 50.4 g lauryl methacrylate
(LMA), 19.6 g SMA and 0.35 g n-dodecyl mercaptan. The resulting
mixture was stirred under nitrogen inert conditions and heated up
to a reaction temperature of 120.degree. C. An initiator mixture
containing 0.143 g tert-butyl-per-2-ethyl-hexanoate and 0.445 g
canola oil was separately prepared. The initiator mixture was fed
to the reaction mixture for 100 minutes in three steps. Step-1:
0.06 gram of initiator mixture over 30 minutes at 120.degree. C.,
step-2: 0.12 gram of initiator mixture over 40 minutes at
120.degree. C., step-3: 0.42 gram of initiator mixture over 30
minutes at 105.degree. C. The reaction was held for another 30
minutes at 105.degree. C. Thereafter, 29.05 gram of Canola oil was
added to bring the product to a desired dilution.
[0104] The molecular weights of PAMA-I and PAMA-II were determined
by SEC (Size Exclusion Chromatography): [0105] Columns: 5 SDV
columns 8.times.300 mm resp. 8.times.50 mm (company PSS at Mainz),
1 solvent-peak separation column 8.times.100 mm (company Shodex)
[0106] Instrument: Agilent 1100 Series [0107] Oven: 35.degree. C.
[0108] Eluent: tetrahydrofuran [0109] Flow rate: 1 mL/min [0110]
Injected volume: 100 .mu.L [0111] RI detection at 40.degree. C.
[0112] Concentration of sample solution: 2 g/L [0113] Standards:
PMMA (PSS Mainz or Polymer Laboratories)
Example 3
Preparation of EVA-Graft-PAMA as Disclosed in U.S. Pat. No.
4,906,682 (RoHm GmbH)
[0114] Dissolve 20 g of EVA copolymer in 150 gram dilution oil by
stirring the mixture at 100.degree. C. overnight. Adjust the
temperature to 90.degree. C. Start feeding 80 g of dodecyl
pentadecyl methacrylate (DPMA) containing 0.5%
tert-butylperoxy-2-ethyl-hexanoate to the EVA copolymer solution
over 3.5 hours. Hold the reaction by stirring the mixture at
90.degree. C. for another 2 hours. Add 0.2%
tert-butylperoxy-2-ethyl-hexanoate and hold for another 45
minutes.
Example 4
Preparation of CFI-I (Cold Flow Improver-I) Additive Containing
PAMA-I and EVA-Graft-PAMA
[0115] Mix 85 g of CFI-I and 15 g of p(EVA-g-DPMA). Blend the
mixture by stirring at 60.degree. C. for a minimum of 1 hour. The
blend appears homogeneous and colourless.
Example 5
Preparation of CFI-II Additive Containing PAMA-II and
EVA-Graft-PAMA
[0116] Mix 85 g of CFI-1 and 15 g of p(EVA-g-DPMA). Blend the
mixture by stirring at 60.degree. C. for a minimum of 1 hour. The
blend appears homogeneous and colourless.
Example 6
Preparation of Additive Composition Containing Antioxidants and
Cold Flow Improvers (Additive A-1)
[0117] In a 50 mL reaction flask, dissolve 15 g of TBHQ in 15 g of
diethylene glycol monobutyl ether at 60.degree. C. under nitrogen
inert conditions for a minimum of one hour. The latter solution is
termed as solution I. In a separate 150 mL reaction flask, blend 50
g of CFI-I and 20 g of BHT at 60.degree. C. under nitrogen inert
for a minimum of one hour. The latter mixture is termed as solution
II. Later mix solution I and solution II at 60.degree. C. under
nitrogen inert conditions for another one hour. The final mixture
contains 50% CFI-I, 15% TBHQ, 15% diethylene glycol monobutyl ether
and 20% BHT (Additive A-1).
Example 7
Preparation of Additive Composition Containing Antioxidants and
Cold Flow Improvers (Additive A-2)
[0118] In a 50 mL reaction flask, dissolve 15 g of TBHQ in 15 g of
diethylene glycol monobutyl ether at 60.degree. C. under nitrogen
inert conditions for a minimum of one hour. The latter solution is
termed as solution I. In a separate 150 mL reaction flask, blend 50
g of CFI-II and 20 g of BHT at 60.degree. C. under nitrogen inert
conditions for a minimum of one hour. The latter mixture is termed
as solution II. Later mix solution I and solution II at 60.degree.
C. under nitrogen inert conditions for another one hour. The final
mixture contains 50% CFI-II, 15% TBHQ, 15% diethylene glycol
monobutyl ether and 20% BHT (Additive A-2).
Example 8
Comparative Examples
[0119] Comparative examples B1 to B6 were all prepared in the
similar manner to the preparation of Additive A-1 and Additive
A-2.
[0120] The details of the variations in the recipe are described in
table 1.
TABLE-US-00002 TABLE 1 Comparative Example Antioxidant Solvent CFI
Mixture stabilizer B-1 15% TBHQ 15% 42.5% PAMA 15% diethylene
glycol (biodiesel flow improver diethylene glycol monobutyl ether
palm methyl ester) + monobutyl ether 7.5% EVA-graft-PAMA B-2 15%
TBHQ 15% 42.5% PAMA 15% diethylene glycol (biodiesel flow improver
diethylene glycol monobutyl ether rapeseed methyl ester) +
monobutyl ether 7.5% EVA-graft-PAMA B-3 15% TBHQ 15% 47% PAMA II +
15% diethylene glycol 3% high oleic sunflower oil diethylene glycol
monobutyl ether monobutyl ether B-4 15% TBHQ 15% 42.5% PAMA II +
15% diethylene glycol 7.5% high oleic sunflower oil diethylene
glycol monobutyl ether monobutyl ether B-5 15% TBHQ 15% 47% PAMA II
+ 15% diethylene glycol 3% soybean oil diethylene glycol monobutyl
ether monobutyl ether B-6 15% TBHQ 15% 42.5% PAMA II + 15%
diethylene glycol 7.5% soybean oil diethylene glycol monobutyl
ether monobutyl ether
[0121] 42.5% PAMA in comparative example B-1, which is a cold flow
improver for fossil diesel oil and biodiesel oil, uses greater C16
and C18 fractions compared to A-1 and A-2. 42.5% PAMA in
comparative example B-2, which is also a cold flow improver for
fossil diesel oil and biodiesel oil, has a number average molecular
weight below 10,000 g/mol, which is significantly lower as compared
to A-1 and A-2. The comparative examples B-3 to B-6 consist of CFI
(cold flow improver) combinations, which exclude EVA-graft-PAMA.
The comparative example B-3 and B-5 used 47% PAMA-II that equals
the polymer actives in comparison to the CFI combination used in
A-2. Whereas, in the comparative example B-4 and B-6 simply
replaces the EVA-graft-PAMA fraction by high oleic sunflower oil
and soybean oil, respectively.
Visual Appearance of the Additives
[0122] Visual appearances of Additives A-1, A-2 and Comparative
Examples B-1 to B-6 are summarized in Table 2.
TABLE-US-00003 TABLE 2 Addi- Visual Appearance tive After 1 day
After 1 week After 2 weeks A-1 miscible and hazy miscible and hazy
miscible and hazy A-2 miscible and hazy miscible and hazy miscible
and hazy B-1 miscible and hazy miscible and hazy miscible and hazy
B-2 miscible and hazy miscible but start presence of two to
re-crystallize phases B-3 Immiscible Clear phase separation Clear
phase separation B-4 Immiscible Clear phase separation Clear phase
separation B-5 Immiscible Clear phase separation Clear phase
separation B-6 Immiscible Clear phase separation Clear phase
separation
[0123] As described earlier in Table 1, the comparative examples
B-3 to B-6 do not contain EVA-graft-PAMA. As shown in the Table 2,
it is clearly indicates that the without the presence of
EVA-graft-PAMA, the individual components in the additive
formulation are immiscible.
Influence of EVA-Graft-PAMA on the Cold Flow Improvement of Oils
and Fats
[0124] In Table 3, examples C-1 and C-2 are PAMA formulations with
and without presence of EVA-graft-PAMA. C-1 and C-2 were then
evaluated with respect to the pour point activity in 2011/53.
TABLE-US-00004 TABLE 3 Sunflower EVA-graft- Oil PAMA II PAMA
(2011/553) treat rate PP Example [wt %] [wt %] [wt %] [ppm]
[.degree. C.] C-1 42.5 7.5 50 0 -15 C-1 42.5 7.5 50 2000 -24 C-2
42.5 -- 57.5 0 -15 C-2 42.5 -- 57.5 2000 -21
[0125] As shown in Table 3, the presence of EVA-graft-PAMA (C-1)
gives a boost in the pour point activity in comparison to C-2,
which doesn't have EVA-graft-PAMA.
Cold Flow and Oxidation Stability of Natural Vegetable Oils with
the Addition of the Additives
[0126] Cold flow ability (pour point, PP) and oxidation stabilities
(reported as induction period measured by Rancimat test) of
different vegetable oils (2012/301, 2012/302, 2012/303 and
2012/304) using the inventive additives are summarized in Table 4.
The performance tests using additives B-2, B-3, B-4, B-5 and B-6
were carried out not during the same period to that of additives
A-1, A-2 and B-1. Therefore, the Rancimat value of the neat
vegetable oils (2012/301 and 2012/302) were measured before
treating the oils with B-2, B-3, B-4, B-5 and B-6.
TABLE-US-00005 TABLE 4 treat rate PP IP Oil Additive [ppm]
[.degree. C.] [hour] .DELTA.IP High oleic A-1 0 -18 6.28 0.00
sunflower 500 -21 10.99 4.71 oil 1000 -21 14.14 7.86 5000 -24 31.19
24.91 10000 -24 44.17 37.89 A-2 0 -18 6.28 0.00 500 -24 11.21 4.93
1000 -24 14.50 8.22 5000 -24 30.82 24.54 10000 -24 43.84 37.56 B-1
0 -18 6.28 0.00 500 -21 11.31 5.03 1000 -21 14.47 8.19 5000 -21
30.59 24.31 10000 -21 41.82 35.54 B-2 0 -15 3.95 0.00 500 -21 6.46
2.51 1000 -21 9.54 5.59 5000 -21 22.16 18.21 10000 -21 35.24 31.29
B-3 0 -15 3.95 0.00 500 -24 7.15 3.20 1000 -24 9.75 5.80 5000 -24
22.48 18.53 10000 -24 34.08 30.13 B-4 0 -15 3.95 0.00 500 -24 6.99
3.04 1000 -24 9.77 5.82 5000 -24 22.80 18.85 10000 -24 33.56 29.61
Soybean oil A-1 0 -9 4.45 0.00 500 -12 7.91 3.46 1000 -12 10.43
5.98 5000 -15 20.07 15.62 10000 -24 29.04 24.59 A-2 0 -9 4.45 0.00
500 -12 7.77 3.32 1000 -12 9.85 5.40 5000 -18 15.63 11.18 10000 -21
28.20 23.75 Soybean oil B-1 0 -9 4.45 0.00 500 -9 6.12 1.67 1000
-12 7.75 3.30 5000 -12 15.59 11.14 10000 -9 27.22 22.77 B-2 0 -9
3.28 0.00 500 -9 4.55 1.27 1000 -9 5.30 2.02 5000 -9 11.80 8.52
10000 -9 23.22 19.94 B-5 0 -9 3.28 0.00 500 -12 4.45 1.17 1000 -15
5.73 2.45 5000 -18 13.46 10.18 10000 -21 16.25 12.97 B-6 0 -9 3.28
0.00 500 -12 4.35 1.07 1000 -15 6.04 2.76 5000 -18 12.75 9.47 10000
-21 20.30 17.02 Canola oil-II A-1 0 -18 5.93 0.00 500 -30 8.90 2.97
1000 -33 12.30 6.37 5000 -33 16.95 11.02 10000 -33 29.12 23.19 A-2
0 -18 5.93 0.00 500 -30 9.68 3.75 1000 -30 10.53 4.60 5000 -33
15.81 9.88 10000 -33 26.15 20.22 High oleic A-1 0 -18 9.65 0.00
canola oil 500 -24 15.30 5.65 1000 -27 17.48 7.83 5000 -30 35.86
26.21 10000 -30 48.34 38.69 A-2 0 -18 9.65 0.00 500 -27 15.59 5.94
1000 -27 18.47 8.82 5000 -30 37.69 28.04 10000 -30 50.11 40.46
[0127] By evaluating the data presented in 3.4, 3.5 and 3.6, the
following values of the additive formulation can be obtained:
[0128] The visual appearance study as summarized in Table 2, i.e.
comparing additive A-1 and A-2 against B-2, B-3, B-4, B-5 and B-6,
indicates that the presence of EVA-graft-PAMA component is
essential to obtain a stable and homogeneous additive formulation
over a longer period of time.
[0129] The presence of EVA-graft-PAMA not only stabilizes the
additive formulation, but also boosts the pour point of the oils
and fats, as shown in Table 3.
[0130] The additive formulation, which is a homogenous solution,
can be used to improve the pour point and the oxidation stability
of various oils and fats, without any antagonistic effects, as
shown in Table 4.
[0131] The choice of PAMA used in the CFI composition is critically
important. The use of an inappropriate choice can lead to an
antagonistic effect both in cold flow improvement and oxidation
stability (see example A-1, A-2 against B-1, B-2).
* * * * *