Fuel and related compositions – Liquid fuels – Containing organic -c
Reexamination Certificate
2001-11-09
2004-09-21
Toomer, Cephia D. (Department: 1714)
Fuel and related compositions
Liquid fuels
Containing organic -c
C044S418000
Reexamination Certificate
active
06793696
ABSTRACT:
BACKGROUND OF THE INVENTION
The present invention relates to reaction products of fatty acids with short-chain oil-soluble amines that possess good cold stability and to their use for enhancing the lubricity of middle distillate fuel oil compositions.
1. Field of the Invention
Mineral oils and mineral oil distillates used as fuel oils generally contain 0.5% by weight or more of sulfur which burns to form sulfur dioxide. To lessen the resultant environmental pollution, the sulfur content of fuel oils is being progressively lowered. The EN 590 standard for diesel fuels currently prescribes a maximum sulfur content of 350 ppm for Germany. In Scandinavia, fuel oils already in use contain as little as 50 ppm of sulfur, exceptionally even less than 10 ppm. These fuel oils are generally produced by hydrorefining the fractions obtained from petroleum by distillation. But the desulfurizing step also removes substances that confer natural lubricity on fuel oils. These substances include polyaromatic and polar compounds.
It has now been determined that the friction and wear reducing properties of fuel oils deteriorate with increasing desulfurization. These properties are frequently so poor that materials lubricated by the motor fuel, for example the distributor injection pumps of diesel engines, are quickly prone to showing signs of pitting. This problem is made more acute by the maximum value for the 95% distillation point as per EN 590 having been set to not more than 360° C. since 2000 and the further reduction in the 95% distillation point to below 350° C. and in some instances to below 330° C. that has in the meantime taken place in Scandinavia.
2. Description of the Related Art
There are prior art proposals for solving this problem with lubricity additives or enhancers.
WO-A-99/36489 discloses the use of mixtures of monomeric and polymeric fatty acids for improving the lubricity of low sulfur middle distillates.
EP-A-0 798 364 discloses salts and amides of mono- to tetracarboxylic acids of 2 to 50 carbon atoms and aliphatic mono-/polyamines of 2 to 50 carbon atoms and 1 to 10 carbon atoms as lubricity enhancers for low sulfur diesel fuel. Preferred amines have 8 to 20 carbon atoms, for example cocoamine, tallowamine and oleylamine.
WO-A-95/33805 discloses the use of cold flow improvers to enhance the lubricity of low sulfur middle distillates. Substances mentioned as suitable include polar nitrogenous compounds containing an NR
13
group, where R
13
is hydrocarbyl of 8 to 40 carbon atoms and can be present in the form of a cation.
WO-A-96/18706 discloses by analogy with WO-A-95/33805 the use of the nitrogenous compounds mentioned therein in combination with lubricity additives.
WO-A-96/23855 discloses by analogy with WO-A-95/33805 the use of the nitrogenous compounds mentioned therein in combination with detergent additives.
EP-A-0 926 221 discloses salts of C
6
-C
20
-alkylphenols with primary or secondary aliphatic C
6
-C
50
-monoamines for improving the lubricity of low sulfur diesel fuel.
WO-A-00/15739 discloses a low sulfur diesel fuel composition possessing improved lubricity, containing at least one dicarboxylic acid, at least one amine having a straight-chain hydrocarbon radical and optionally a monocarboxylic acid. The substances can be present as physical mixtures or else as salts, amides and/or imides. The additized oils exhibit improved lubricity, stability in storage and corrosion control.
The fatty acids, fatty acid ammonium salts and fatty acid amides used in the prior art have the disadvantage of solidifying on storage at low temperatures, i.e., frequently at room temperature, usually at temperatures of 0° C., at the latest at −5° C., or that crystalline fractions separate and cause handling problems. This problem is only partly solvable by diluting with organic solvents, since fractions will crystallize out even from these solutions or the solution will gel and solidify. For use as lubricity additives they consequently have to be greatly diluted or kept in heated storage vessels and added via heated pipework.
It is an object of the present invention to provide lubricity additives that enhance the lubricity of middle distillates, but remain homogeneous, clear and especially flowable at low temperatures and do not adversely affect the cold flow properties of middle distillates.
SUMMARY OF THE INVENTION
It has been found that reaction products of fatty acids with branched, short-chain, oil-soluble imines remain flowable and clear for a prolonged period even at substantially lower temperatures, in some instances to below −20° C., in special cases to below −50° C., and enhance the lubricity of middle distillates more efficiently than pure fatty acids of the prior art.
DETAILED DESCRIPTION OF THE INVENTION
This invention accordingly provides a fuel oil composition comprising a middle distillate having a sulfur content of up to 0.05% by weight and reaction products of mono- or dicarboxylic acids of 6 to 50 carbon atoms and primary, secondary or tertiary amines of the formula
NR
1
R
2
R
3
where R
1
is branched alkyl of 3 to 18 carbon atoms and R
2
and R
3
are independently hydrogen, R
1
or alkyl of 1-12 carbon atoms.
The present invention further provides for the use of the reaction products mentioned for improving the lubricating properties of low sulfur middle distillates.
The present invention yet further provides an additive for enhancing the lubricity of middle distillates having a sulfur content of up to 0.05% by weight, comprising reaction products of mono- or dicarboxylic acids of 6 to 50 carbon atoms and primary, secondary or tertiary amines of the formula
NR
1
R
2
R
3
where R
1
is branched alkyl of 3 to 18 carbon atoms and R
2
and R
3
are independently hydrogen, R
1
or alkyl of 1-12 carbon atoms.
Preferred fatty acids (ingredient A) are fatty acids of 8 to 40 carbon atoms, especially 12 to 22 carbon atoms. They may contain one or more double bonds and be of natural or synthetic origin. Ingredient A preferably comprises fatty acids that contain at least one double bond or fatty acid mixtures in which at least 50% by weight, especially at least 75%, specifically at least 90%, of the ingredients contain one or more double bonds. In polyunsaturated carboxylic acids, the double bonds may be isolated or else conjugated. The fraction of saturated fatty acids is preferably below 20%, especially below 10%, specifically below 5%. The alkyl radicals of the fatty acids consist essentially of carbon and hydrogen. However, they may carry further substituents such as for example hydroxyl, hydrogen, amino or nitro groups, provided these do not impair the predominant hydrocarbon character. Useful fatty acids include for example lauric acid, tridecanoic acid, myristic acid, pentadecanoic acid, palmitic acid, margaric acid, stearic acid, isostearic acid, arachidic acid, behenic acid, oleic acid, erucic acid, palmitoleic acid, myristoleic acid, linoleic acid, linolenic acid, elaeosteric acid and arachidonic acid, ricinoleic acid and also fatty acid mixtures obtained from natural fats and oils, for example coconut oil fatty acid, peanut oil fatty acid, fish oil fatty acid, linseed oil fatty acid, palm oil fatty acid, rapeseed oil fatty acid, ricinenic oil fatty acid, castor oil fatty acid, colza oil fatty acid, soybean fatty acid, sunflower oil fatty acid, and tall oil fatty acid. Preferred fatty acid (mixtures) have iodine numbers of at least 40 gl/100 g, preferably at least 80 gl/100 g, especially at least 125 gl/100 g.
It is likewise possible to use dicarboxylic acids, such as dimer fatty acids and alkyl- and alkenylsuccinic acids having C
8
-C
50
-alk(en)yl radicals, preferably C
8
-C
40
-, especially C
12
-C
22
-alkyl radicals. The alkyl radicals may be linear or branched (oligomerized alkenes such as oligopropylene, polyisobutylene).
The fatty acids may further contain 1-40%, specifically 1-25%, of resin acids.
Useful amines (ingredient B) are primary, secondary and tertiary amines carrying at least one branched C
3
-C
18
-alkyl radical, preferably C
Krull Matthias
Kupetz Markus
Clariant GmbH
Silverman Richard P.
Toomer Cephia D.
LandOfFree
Enhanced lubricity fuel oil compositions comprising salts of... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Enhanced lubricity fuel oil compositions comprising salts of..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Enhanced lubricity fuel oil compositions comprising salts of... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3243623