NO138288B - FUEL MIXTURE. - Google Patents

Description

The invention relates to a fuel mixture whose main component is a normal motor fuel and which also contains a small amount of an additive.

The characteristic feature of the fuel mixture according to the invention is that the additive is a compound obtained by reacting equimolar amounts of

there of a linear polyamine of the general formula:

where R<1> is a straight-chain, saturated or unsaturated, monovalent ali-

phatic hydrocarbon radical of 6-20 carbon atoms, n is an integer from 3 to 10, and m is an integer from 1 to 10, with a compound of the general formula

where and R^ is a hydrogen atom or a straight-chain, monovalent

aliphatic hydrocarbon radical with 1-12 carbon atoms. Alternatively, the additive consists of a neutralization product of the above-mentioned for-

bond with at least one monoalkyl and/or dialkyl phosphoric acid of the general formula:

where R" is a saturated aliphatic, monovalent hydrocarbon radical with 8 to 18 carbon atoms, where the amount of phosphoric acid is such that

the number of -OH groups does not exceed the number of amino groups in the said compound, optionally together with the above-mentioned, non-neutralized compound.

The additive is included in the fuel mixture according to the invention in an amount of from 10 to 250 ppm, calculated on the weight of the motor fuel.

The additives described here have a cleaning effect, and they can also be used as anti-icing agents and anti-corrosion agents, especially for such fuel mixtures that are used in engines with spark ignition.

The additives also have weaning properties.

It is known that the use of petrol-based propellants, especially in car engines, causes many problems for the carburettor. thus, it is known that the formation of significant deposits on the various elements in the carburettor is responsible for misfiring and seizing of the engine, which occurs frequently in car engines, especially in city traffic and/or in hot weather. This formation of deposits is further aggravated by the use of suction devices for the gases from the crankcase, known under the name "Positive Crankcase Ventilation" (PVC), which aims to reduce the pollution of the atmosphere. One knows, among other things, that under certain conditions with respect to humidity and temperature in the air, ice crystals form on the metal walls of the carburettor, where they stick. They can accumulate there in a quantity that is sufficient to clog the inlet opening in the valve in the carburettor.. It is finally known that water dissolved in the petrol can cause corrosion on the metal parts in the engine..

Attempts have been made to reduce these disadvantages by adding to the petrol, in concentrations which are generally very low (of the order of 50 ppm), various additives whose function is to prevent the formation of deposits in the carburettor (cleaning effect), to prevent the attachment of ice crystals on the metal walls (anti-icing effect) and to develop a protective film on the various metal parts of the engine (anti-corrosion effect).

In order to combine the different effects in a single molecule, it has already been proposed to use as additives different organic compounds which generally comprise one or more linear components which are soluble in the petrol, as well as one or more polar components.

It is known, for example, from French patent document no.

1,439,026 that the reaction products of alkenyl succinic anhydrides and

imidazolines can be used as additives that have washing and anti-corrosion properties, especially in fuel mixtures for petrol engines. It is also known from US Patent No. 3,223,495 that alkenylsuccinic acid imidamines can be used as dispersants in additives with combined dispersing and washing properties for motor fuel mixtures.

When in formula (IT) above R 1 and R 2 represent aliphatic hydrocarbon radicals, they preferably consist of alkyl radicals, e.g. the radicals methyl, ethyl, propyl, n-butyl, isobutyl, hexyl and dodecyl.

However, maleic anhydride is most often used

(Rx = R2 - H).

In formula (I) above, R' is preferably an alkyl radical or alkenyl radical. As specific examples of linear polyamines the following can be mentioned: N-oleylpropanediamine, N-stearylpropanediamine and mixtures thereof, as well as N-hexylpropanediamine, N-eicosylpropanediamine, N-oleyl-dipropylenetriamine, N-oleyl-penta-propylenehexamine, N -oleyl-decapropylene-undeca-amine, N-stearyl-pentamethylenediamine, N-stearyl-octamethylenediamine and N-stearyldeca-methylenediamine.

As solvents that are inert towards the reaction partners, one can e.g. use an aromatic hydrocarbon or a mixture of aromatic hydrocarbons, e.g. benzene, toluene,

a xylene or a mixture of xylenes..

The reaction temperature is preferably kept below 55°C.

The reaction water is removed, e.g. azeotropic when it

used solvent forms an azeotropic mixture with the water.

As indicated in French Patent Document No. 1,447,520, it has been established that the increase in polar groups obtained by reacting the aforementioned nitrogen compounds with compounds of the alkylphosphoric acid type significantly increases the solubility of the additive in the mixtures of aromatic solvents and improves certain of the aforementioned effects, especially the anti-icing effect.

Examples of alkyl phosphoric acids which can be used for neutralizing the additive included in the fuel mixture according to the invention are mixtures of monoalkyl and dialkyl phosphoric acids which are obtained by the action of phosphoric anhydride on an alcohol or a mixture of aliphatic, linear or branched, alcohols , these mixtures being particularly advantageous.

The additives described here are added as they are or

in partially or completely neutralized form by means of alkyl phosphoric acids, for the fuel mixtures according to the invention, in concentrations of 10 to 250, preferably 10 to 100, ppm by weight, which means that no difficulties are observed in the carburettor, even if the addition takes place at low temperature. These additives can be added without disadvantage to the usual additives. Thus, when the described additives are used in a carburettor in connection with a small amount of at least one mineral oil, additives with a rejecting effect will also be present. One thus uses from 50 to 2000 ppm by weight of a mineral oil, e.g. a naphthenic oil, and 10 to 250 ppm by weight of at least one compound as described herein, calculated on the fuel mixture.

The following examples illustrate the invention:

EXAMPLE 1

32.4 g of N-oleyl-propanediamine (0.1 mol) and 9.8 g of maleic anhydride (0.1 mol) were dissolved in 100 cm 3 of a mixture of toluene and xylene in 50-50 parts by volume. The solution was refluxed until all the water of reaction had been removed azeotropically. 1.8 g of water were thus collected, and an N-(oleylamino-3-propyl)-imide compound was obtained in solution. A portion of this

solution is evaporated to dryness, and an I.R. is performed. - determination of the resulting viscous residue. Bands characteristic of the imi d function ion (at approx. 1700 and 1775 cm<->"'") and a broad band characteristic of the amine function (at approx.

3300 cm"^). The remainder of the solution is adjusted to a known volume using the aforementioned solvent mixture, to prepare a standard solution.

EXAMPLE 2

17.7 g of an equimolecular mixture of mono- and dioctyl phosphoric acids is added to the solution mentioned above, which corresponds to

rer about 0.1 hydroxyl equivalent. The addition is carried out so that the temperature in the mixture stays below 65°C. The reaction mixture is then brought to 80-85°C over the course of one hour with vigorous agitation. An oily product is obtained which. one adjusts to a known volume using a toluene/xylene mixture, 50-50 parts by volume, to obtain the desired solution.

EXAMPLE 3

84.6 kg of xylene, 0.100 kg of hydroquinone, 83.2 kg of an equimolecular mixture of N- are introduced into a 200-liter glass reactor. oleylpropanediamine and N-stearylpropanediamine (trade name "DINORAM-S") and 21.5 kg of maleic anhydride. The duration of the introduction is 8 hours at an average temperature of 45-50°C. You heat the reaction mixture, which is pink in colour, and you see when the temperature reaches 75-80°C that the color changes to red-violet. Heating is continued to the reflux temperature of the xylene. After 5 hours of azeotropic distillation, 5200 kg of water has been collected, removed with xylene. The mixture is cooled.

A mixture of the N-(oleylamino-3-propyl)-imide compound and an N-(stearylamino-3-propyl)-imide compound is obtained in solution. A portion of this solution is evaporated to dryness and an I.R. determination is performed on the resulting viscous residue. Bands characteristic of the imide function (at about 1700 and 1775 cm"<1>) and a broad band characteristic of the amine function (at about 3300 cm<-1>) are observed. The rest of the solution is adjusted to a known volume by adding xylene, and the solution is divided into two fractions of equal volume.

EXAMPLE 4

To one part of the solution from example 3 is added 19 kg of an equimolar mixture of mono- and dioctyl phosphoric acids, which corresponds to approximately all the salt-forming amine groups in the mixture of maleimido-amines present in the fraction used. The addition is carried out so that the temperature remains below 65°c. The reaction mixture is then brought to 80-85°C during 1 hour under vigorous agitation. An oily product is obtained which is adjusted to a known volume using xylene.

EXAMPLE 5

Determination of carburetor efficiency

A Renault R16 engine, type 69 .7.0.1, is used, equipped with a carburettor of type Solex 35 D.I.T.A.2. This engine was lubricated with a commercial oil, multigrade 20W40 o,g, and a super fuel whose composition by weight is as follows:

aromatic hydrocarbons 38%

olefins 1%

saturated hydrocarbons 61%

and which otherwise includes 0.48 g/l of lead.

The engine is run for 48 hours, while 10 to 12% of the exhaust gases are recirculated. Each attempt consumes approx. 200 liters of super fuel.

For each trial, a new carburettor (with efficiency equal to 10) is used. The carburettor is dismantled at the end of each trial, and its efficiency is noted down.

Table I below summarizes the results for the experiments carried out with the super fuel described above:

1) without cleaning additives,

2) with 45 ppm (by weight) of the compound according to Example 3, 3) with 45 ppm (by weight) of the compound according to Example 4, 4) with 150 ppm (by weight) of the compound according to Example 3 , 5) with 150 ppm (by weight) of the compound according to Example 3 and 600 ppm (by weight) of a naphthenic oil of viscosity 293.5 cS at 38°C and 16.25 cS at 99°C.

EXAMPLE 6

Declare test for the carburettor

When using the engine and the type of carburettor which

is described in the previous example, the carburettor is de-slaged while the engine is run for 48 hours with the super fuel without additive and by recycling 15 to 17% of the exhaust gases.

After the slagging cycle, the carburettor, which was initially new (efficiency 10), shows an efficiency of 2.

The engine is then run for 23 hours in normal operation with the super fuel added with 250 ppm by weight of the compound from example 3 and 600 ppm by weight of the naphthenic oil described in the previous example.

After this cycle, the carburetor exhibits an efficiency of 6.4, giving an efficiency gain of 4.4 over the efficiency of 2 observed prior to this experiment.

EXAMPLE 7

Declagging test in the carburettor

This test is not carried out to show the properties of the carburettor, but to show the content of carbon oxide emitted with the exhaust gases.

De-slagging is carried out in the carburettor in the same way as described in the previous example, and table II below indicates the percentage of carbon monoxide emitted at the beginning of the experiment and after 30 hours of de-slagging.

The engine is then allowed to run in normal operation with the super fuel added with 250 ppm by weight of the compound from example 3 and 650 ppm by weight of the naphthenic oil described in example 5. The carbon oxide content is indicated in table III below:

EXAMPLE 8

Determination of anti-icing quality

The measurement method I.F.P. was used. which is described in "Carburants et Combustibles pour moteur a combustion interne",

J. WEISSMANN, Ed. TECHNIP (1970), using the super fuel described in example 5 and as an additive the compound from example 3 in different concentrations. The results are compared in Table IV below:

EXAMPLE 9

Anti-corrosion test

This test is performed in accordance with ASTM D-665-60.

30 cm 3 of synthetic seawater is added to 300 cm 3 of petrol which comprises 45 ppm by weight of the compound ice from example 3. This mixture is kept at 38°C for 24 hours in the presence of a polished steel rod.

After the experiment, the steel bar was still shiny. analogously, a piece of the carburettor retains its luster.

When using petrol without additive, under the same conditions, the steel and metal in the carburettor are covered with oxides.

EXAMPLES 10-20

In these examples, such imide compounds as are used according to the invention were prepared. These compounds were added to gasoline and tested according to the methods described in Examples 5 to 9.

The investigated compounds were prepared by reaction of a maleic anhydride and a polyamine corresponding to the previously indicated general formulas (I) and (II), where R1, R2, n, m and R1 have. the following designations:

The results of the tests were analogous to those given for examples 5 to 9.

An I.R. determination performed on the products prepared in Examples 10-20 showed, after evaporation to dryness, bands characteristic of the imide function and a broad band characteristic of the amine function.

In order to show that the compounds that are produced

according to the invention, has an unexpectedly beneficial effect compared to known compounds, the following experimental data are provided:

PREPARATION A (French patent no. 1,439,026)

a) An alkenylsuccinic anhydride is produced by reacting 270 g of maleic anhydride and 2700 g of a polyisobutylene with

average molecular weight 1100, at a temperature of approx. 250°C for approx. 19 hours. After cooling to approx. At 60°C, the reaction mixture is diluted with 50% of its own weight of toluene, and filtered. The toluene evaporates overnight in a steam bath.

b) An imidazoline is produced by reaction under reflux cooling for approx. 16 hours of 5 moles (945 g) of tetraethylenepentamine and 5 moles (300 g) of glacial acetic acid, in the presence of 125 g of xylene, the water formed being recovered in a Dean/Stark apparatus. The resulting product is then cooled and the xylene is removed by blowing off with a stream of nitrogen while heating on a steam bath. c) In the presence of 70 g of toluene, 50.2 g of the imidazoline and 300 g of the alkenyl succinic anhydride prepared as described above are reacted by heating at approx. 125°C for approx. 8 hours. The water that forms is recovered in a Dean/Stark facility. The toluene is then removed from the product obtained by blowing off using a stream of nitrogen while heating in a steam bath.

The product thus obtained is labeled Additive A.

PREPARATION B (US patent no. 3,223,495)

An alkenyl succinimide which is prepared by reaction of approx. 1 mol of a polybutene of average molecular weight from 1200 to 1600, with 1 mol (98 g) of maleic anhydride at a temperature of approx. 225-250°C for approx. 6 hours. The resulting product is then dissolved in a 50% by weight xylene solution, and tetraethylenepentamine

t is added gradually while stirring, while the temperature is kept at approx. 50°C, and the water of reaction is removed azeotropically by stripping off the xylene solvent.

The obtained product is labeled Additive B.

Comparison tests

The same test described in Example 5 was carried out with the same super petrol, but containing

1 - 150 ppm by weight of Additive A

2 - 150 ppm by weight of Additive B

Carburetor performances were 7.1 and 6.6, respectively, with gains in performance with respect to gasoline without additive of 3.3 and 2.8, respectively.

From these results, it can be seen that the known compounds that have been investigated have lower washing activity than compounds used according to the invention, when they are used at the same concentration in the same petrol (see Table I, columns 4 and 5).

Claims (5)

1. Fuel mixture comprising a main quantity of a regular motor fuel and a smaller quantity of an additive, characterized in that the additive is a compound obtained by reacting, in an inert solvent, equimolar quantities of a linear polyamine of the general formula where R' is a straight-chain, saturated or unsaturated, monovalent aliphatic hydrocarbon radical of 6-20 carbon atoms, n is an integer from 3 to 10, and m is an integer from 1 to 10, and a compound of the general formula where R^ and R« are a hydrogen atom or a straight-chain, monovalent aliphatic hydrocarbon radical with 1-12 carbon atoms, or that the additive consists of a neutralization product of the aforementioned compound with at least one monoalkyl and/or dialkyl phosphoric acid of the general formula: where R" is a saturated aliphatic, monovalent hydrocarbon radical with 8 to 18 carbon atoms, where the amount of phosphoric acid is such that the number of -OH groups does not exceed the number of amino groups in the aforementioned compound, optionally together with the above-mentioned, non-neutralized compound, the amount of the additive is from 16 to 250 ppm, calculated on the weight of the motor fuel. 2. Fuel mixture as stated in claim 1, characterized in that the amount of the additive is from 10 to 100 ppm, calculated, on the weight of the motor fuel.. 3. Fuel mixture as stated in any one of claims 1 to 2, characterized in that it further contains a small amount of at least one mineral oil. 4. Fuel mixture as specified in any of claims 1 to 3, characterized in that the additive is obtained by reacting N-oleylpropanediamine and/or N-stearylpropanediamine and maleic anhydride. 5. Fuel mixture as stated in any of claims 1 to 4, characterized in that the additive is the neutralization product obtained with a mixture of mono- and dioctyl phosphoric acids.