Fuel and related compositions – Liquid fuels – Organic oxygen compound containing
Reexamination Certificate
2001-08-21
2003-03-18
Toomer, Cephia D. (Department: 1714)
Fuel and related compositions
Liquid fuels
Organic oxygen compound containing
C044S447000, C568S606000, C568S618000, C568S840000
Reexamination Certificate
active
06533830
ABSTRACT:
The present invention relates to special polyalkene alcohol polyalkoxylates, their use as carrier oils for detergents and dispersants in fuel and lubricant compositions and fuel and lubricant additive concentrates and fuel and lubricant compositions themselves which contain these polyalkene alcohol polyalkoxylates.
Carburetors and intake systems of gasoline engines as well as injection systems for fuel metering are increasingly being contaminated by dust particles from the air, uncombusted hydrocarbon residues from the combustion chamber and the crank case vent gases passed into the carburetor.
To avoid these disadvantages, additives (detergents) are added to the fuel to keep valves and carburetor or injection systems clean. Such detergents are generally used in combination with one or more carrier oils. The carrier oils perform an additional wash function, often support and promote the detergents in their cleaning and keeping clean effect and can thus help to reduce the amount of detergents required. The carrier oils usually used are viscous, high-boiling and in particular heat-stable liquids. They coat the hot metal surfaces, for example the intake valves, with a thin liquid film and thus prevent or delay the formation and deposition of decomposition products on the metal surfaces.
Frequently used carrier oils are, for example, high-boiling refined mineral oil fractions, but also synthetic liquids, such as oil-soluble adducts of alkylene oxides with alcohols. EP-A 277 345 describes adducts of ethylene oxide, propylene oxide and/or butylene oxide with polybutyl or polyisobutene alcohols as carrier oils in fuel or lubricant compositions, it being possible for from 1 to 200 such alkylene oxide units to undergo addition per mole of alcohol, but the molecular weight of the polyisobutene should not be exceeded.
However, the carrier oils known from the prior art frequently have only limited compatibility with other additives, so that separation may occur. Furthermore, the generally high viscosity of these carrier oils often gives rise to formulation problems. In particular, they are not yet capable of completely eliminating the undesired effect of “sticking of the valves”. “Sticking of the valves” is understood as meaning complete loss of compression on one or more cylinders of the internal combustion engine if—owing to polymer deposits on the valve shaft—the spring force is no longer sufficient to close the valves properly.
It is an object of the present invention to provide carrier oils for detergents and dispersants in fuel and lubricant compositions, which carrier oils no longer have the prior art problems described. In particular, these carrier oils should as far as possible be additionally effective as detergents.
We have found that this object is achieved by polyalkene alcohol polyalkoxylates of the formula I
R—(CH
2
)
n
—(O—A)
m
—OH (I)
where
R is a polyalkene radical derived from C
2
- to C
30
-alkenes and having a number average molecular weight of from 300 to 5000,
A is an alkylene group of 2 to 8 carbon atoms,
m is a number up to 200, with the proviso that the oxygen in the oxyalkylate radical —A—(O—A)
m-1
—OH accounts for at least 16.5% by weight of the number average molecular weight of the total molecule of the compounds I, and
n is 0 or 1.
Suitable radicals R are straight-chain or branched hydrocarbon groups which are derived from C
2
- to C
30
-alkenes, in particular from C
3
- to C
12
-alkenes, especially from C
3
- to C
6
-alkenes. Examples of typical alkenes are ethene, propene, butenes, pentenes, hexenes, heptenes, octenes, nonenes, decenes, undecenes and dodecenes. Of particular interest are propene, n-butene and isobutene. The polyalkene on which the hydrocarbon radical R is based is obtainable by oligomerization or polymerization of these alkenes, the oligomerization or polymerization being carried out as a rule (for example by cationic or coordinate oligomerization or polymerization) so that the chain termination leads to a double bond which can be further functionalized to give the corresponding polyalkene alcohol.
R is preferably a polybutyl or polyisobutyl radical derived from isobutene and up to 20% by weight of n-butene and having a number average molecular weight (M
N
) of from 300 to 2500. R is particularly preferably a polybutyl or polyisobutyl radical having a number average molecular weight of from 350 to 1500, in particular from 400 to 850, especially from 450 to 700. Preferably, R is also composed solely of isobutene units.
R may preferably be based on highly reactive polyisobutene (having double bonds predominantly in the a position) which—as described in EP-A 277 345—can be converted into the corresponding alcohol R—CH
2
—OH (n=1) by hydroformylation. When n=0 the preparation of corresponding polybutene or polyisobutene alcohols is usually carried out starting from polybutenes or polyisobutenes having double bonds which are predominantly further inside the polymer chain (for example in the &bgr; or &ggr; position); these are then usually converted into the poly(iso)butene alcohols either by ozonolysis and subsequent reduction or by epoxidation and subsequent reduction or by hydroboration and subsequent hydrolysis or by halogenation with chlorine or bromine and subsequent alkaline hydrolysis.
The alkylene group A is preferably derived from corresponding alkylene oxides, such as ethylene oxide, propylene oxide, 1,2-butylene oxide and cis- or trans-2,3-butylene oxide. However, it may also be 1,3-propylene, 1,4-butylene, 1,6-hexylene or 1,8-octylene. A may also be a mixture of different groups from among the stated groups. A is particularly preferably a 1,2-propylene group, a 1,2-butylene group or a mixture thereof.
The lower limit for the degree of alkoxylation m is determined by the proviso that the oxygen in the oxyalkylate radical —A—(O—A)
m-1
—OH accounts for at least 16.5% by weight of the number average molecular weight of the compounds I. The preferred upper limit m depends on the molar mass of this polyalkene alcohol. Typically, however, this upper limit is 100, in particular 45, especially 35, alkylene oxide units.
The number m may be an integer where only a single type of molecules of the compound I is present, or a fraction where a mixture of different (usually homologous) types of molecules of I is present.
The oxygen in the oxyalkylate radical —A—(O—A)
m-1
—OH preferably accounts for at least 17.5% by weight, especially 18.5% by weight of the number average molecular weight of the total molecule of the compounds I.
In a preferred embodiment, the molar mass of the oxyalkylate radical —A—(O—A)
m-1
—OH is greater than the molar mass of the parent polyalkene alcohol R—(CH
2
)
n
—OH. The molar mass of the oxyalkylate radical —A—(O—A)
m-1
—OH is in particular from 1.5 to 5 times, especially from 2 to 4 times, the molar mass of the parent polyalkene alcohol R—(CH
2
)
n
—OH. The molar mass calculations relate to the number average molecular weights.
The novel polyalkene alcohol polyalkoxylates I can be prepared by conventional methods, for example by reacting the parent polyalkene alcohols R—(CH
2
)
n
—OH with the corresponding amount of alkylene oxide in the presence of suitable catalysts, such as potassium hydroxide preferably in an amount of from 0.01 to 1% by weight, particularly from 0.05 to 0.5% by weight of potassium hydroxide, based on the amount of the reaction product expected. Typical reaction temperatures are from 70 to 200° C., in particular from 100 to 160° C. The pressure is usually from 3 to 30 bar. The reaction product is worked up in the usual manner by expelling volatile components under reduced pressure and, if required, by filtration.
The novel polyalkene alcohol polyalkoxylates I are very suitable as carrier oils for detergents and dispersants in fuel and lubricant compositions. They are particularly preferably used in fuel compositions, in particular in gasoline fuel compositions.
Examples of conventional detergents are:
(a) polyisobuteneamines which are obtainable, according to EP-A 244 616
Günther Wolfgang
Oppenländer Knut
Rath Hans Peter
Trötsch-Schaller Irene
BASF - Aktiengesellschaft
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Toomer Cephia D.
LandOfFree
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