Note: Descriptions are shown in the official language in which they were submitted.
FUEL F~R OTTO-CYCLE ENGINES
20~Q~i~
The present invention relates to a otto-cycle engine fuel con-
taining a minor amount of an amide of an aminoalkylene polycarboxylic acid
and a secondary long-chain amine.
wThe carburetor and suction system in otto-cycle engines and also
the injection system for metering fuel in otto-c~cle and diesel
engines are becoming more and more contaminated by tust particles from the
air, by unburned hytrocarbon residues from the combustion chamber and by
crankcase breather gases suc~ed into the carburetor.
When the engine runs under no-load or low-load conditions, these residues
effect a shift in the air/fuel ratio to produce a richer mixture. The re-
sult is less complete fuel combustion, which in turn increases the propor-
tion of unburned or partially burned hydrocarbons in the exhaust and ef-
sofects a rise in fuel consumption.
known method of overcoming such drawbacks is to use fuel additives de-
signed to keep valves, carburetors and in~ection systems clean (cf., for
example, ~. Rosse~beck ln ~atalys~toren, Tenslde, Mlner~l~ladtitive,
2~ edited by J. Falbe ~nd U. H~sserodt, pp. 223 et seq. G. Th~eme Verlag,
Stuttg7rt 197~).
At present, such detergent atditives sre divided into two genorations de-
pending on their action and the~r preferential locus of action.
.0
The first additive generstion was only capable of preventing new teposits
in the suction system without being able to remove old deposits, whll~t
modern atditives of the second generation can do both (Ukeep-clean~ and
~clean-up~ effects) and are partic~larly effective, due to changed thermal
.,properties, in high-temperature zones, i.e. at the inlet valves.
The principle underlying the molecular structure of fuel detergents may be
generalized BS the linkage of polar structures with non-polar or
lipophilic radicals ~sually of relatively high molecular weight.
o
Particularly useful representatives of the second generation of additives
are, in addition to products based on polyisobuteDes, e.g. polyisobutyl-
amine as tescribet in DE-OS 3,611,230, and in particular amides, imides
and combined imide/amides of various carboxylic acids and polycarboxylic
sacids.
IL~"F A~ti~n~e~llschnt 2 O~Z.0050/1.133~
, Particularly noteworthy in this respect are the known active2 ~ ~r
based on trilon derivatives and higher branched amines as described in EP-
A2 0,006,527.
SUe have now found, surprisingly, that a particularly good carburetor and
valve cleaning effect is achieved when a fuel for otto-cycle en-
giDes contains, in a concentration of from 100 to 500 ppm, an amide, an
amide/ammonium salt or an ammonium salt of an aminoalkylene polycarboxylic
acit and a secondary fatty amine or a mixture thereof of the formulae I
.oand II
,N-CO-cH2 /CH rCO-N~
N-A-N (I)
,N-co-c62 CH2-CO-N~
~, R
f H2--CO--~
N\--CH~-CO-N~ (II)
CH2--CO--N~
in which
A is a straight-chain or branched-chain alkylene radical of from 2 to 6
carbon atoms or a radical of the formula
-CH2_cH2-l-cH2_cHR_
CH rCON~
and
u
R denotes substantially straight-chain aliphatic radicals, particularly
C~O-C3D-alkyl and preferably Cl4-C24-alkyl, and some or all of the amide
structures may be in the form of ammonium structures of the formula
~s R e
/~ .
The amides or amide/ammonium salts or ammonium salts of, for example, ni-
trilotriacetic~acid, ethylenediaminotetraacetic acid or propylene-1,2-di-
aminotetraacetic acid are obtained by reacting the acid with from 0.5 to
1.5, preferably 0.8 to 1.2, moles of amine per carboxyl group.
3-
BASF Alcti~ ellsc~sf~ 3 O.Z.ODSO/41339
2 ~
The reaction temperature is between approx. 80 and 200 C, and to prepare
the amides, continuous removal of the water of reaction is required. How-
ever, complete conversion to amide is not necessary and it is highly ac-
ceptable for from OZ to lOOX molar of the amine reacted to be converted to
,the ammonium salt.
Suitable amines of the formula
~H
R
~are, in particular, dialkylamines in which R is a straight-chain C10-C30-
and preferably Cl4-C24-alkyl radical. Specific examples are dioleylamine,
dipalmitinamine, dicoconut fatty smine, dibehenylamine and, preferably,
ditallow fatty amine.
20 The amides or ammonium salts of aminoalkylene polycarboxylic acids of for-
mulae I and II to be used in the present invention are added to the fuel
in an amount of from 50 to 1000 ppm and preferably from 100 to 500 ppm.
A suitable otto-cycle engine fuel is a leaded or unleaded normal
2~ or super gasoline. Such gasoline may contain components other than hydr~-
carbons, for example alcohols such as methanol, ethanol and t-butanol or
ethers such as methyl-t-butyl ether. In addition to the smides of
aminoalkylene polycarboxylic acids to be used in accordance with the pre-
sent invention, the fuel will usually contain further additives such as
,Ocorrosion inhibitors, stabilizers, antioxidants and/or detergents.
Corrosion inhibltors are usually ammonium salts of organic carboxylic
acids showing a tendency to film formation due to an appropriate structure
of the parent compounds. Amines are also frequently present in corrosion
" inhibitors to lower their p~. Corrosion inhibitors for non-ferrous metals
usually comprise heterocyclic aromatics.
Examples of antioxidants or stabilizers are, in particular, amines such as
para-phenylenediamine, dicyclohexylamine, morpholine or derivatives of
~ossid amines. Phenolic antioxidants such as 2,4-di-t-butylphenol or 3,5-di-
t-butyl-4-hydroxyphenyl propionic acid and derivatives thereof are also
added to fuels and lubricants.
IIASF ~Uctl~nges~llscD~t ~ U.~..UI/~V~ Y
2 ~ J $
Other carburetor, injector and valve detergents which may be present in
the fuel are, for example, amides and imides of polyisobutylene succin-
aldehyde, polybutene polyamines and long-chain carboxamides and long-chain
carboximides.
Examples
A) Preparation of amides of nitriloacetic acids
1)240 g (0.48 mole) of ditallow fatty amine and 35 g (0.12 mole)
of ethylenediaminotetraacetic acid were melted and heated at
190 C while the resulting water of reaction was distilled off
continuously. The reaction was stopped after running for about
25 hours, at which point the acid number was ~5 and the amine
number was <1.1. A water jet vacuum was applied for 2 hours at
120 C to complete the removal of the water of reaction. There
were obtained 265 g of a brown waxy solid, which can be dis-
solved in, say, xylene for easier handling.
2)100 g (0.2 mole) of titallow fatty amine ant 14.6 g (0.05 mole)
of ethylenediaminotetraacetic acid were heated at 180-C for 8
hours, at which point some 50Z of the amine had broken down to
the amide (acid number 45.8, theory - 49.7). There were obtained
97.6 g of the amide/ammonium salt as a light-brown waxy solid.
2~
3)To a melt of 229.5 g (0.45 mole) of ditallow fatty amine were
added 28.65 g (0.15 mole) of nitrilotriacetic acid (trilon A) at
80 C. The reaction mixture was then heated at 180-190-C for 10
hours. To effect total removal of the water of reaction, the
,o product was dried for a further 2 hours at 120'C under a water
jet vacuum. There were obtained 249 g (theory - 250 g) of a
light-brown waxy solid.
B) Tests on valve-cleaning properties
~,
Product Deposits [mg~*
on valve No.
1 2 3 4
~D Polyisobutylamine
(OE-OS 3,611,230) 3 0 2
Exampl e (A) (1) 44 ' O O O
, *measured as specified in CEC-~-02-T-79
