SK97094A3 - Additives for leadless motor petrols and propellants containing these additives - Google Patents

Abstract

A novel anti-wear additive to unleaded internal combustion engine fuels (petrols) contains at least one alkali metal salt or alkaline earth metal salt of an alkyl sulphosuccinate in combination with a detergent and, if appropriate, with other fuel additives known per se.

Description

Additives for unleaded motor fuels and propellants containing these additives

Technical field

The invention relates to additives for unleaded motor gasoline for reducing or preventing wear on valve seats which essentially comprise an alkali metal or alkaline earth metal salt of an organic sulfonic acid and at least one ash-free detergent, and optionally other known additives.

In addition, the invention relates to fuels which contain said additives #

BACKGROUND OF THE INVENTION

The introduction and expansion of unleaded gasoline has created the problem that motor vehicles that could be operated with leaded gasoline without knocking the engine showed dramatic exhaust valve wear when unleaded gasoline was used.

As an aid, among other measures, the addition of additives to the fuel used was proposed.

These additive / wear protection valves protect the exhaust valve seats of internal combustion engines and allow the use of unleaded gasoline also for the operation of older motor vehicles not yet specially equipped for unleaded gasoline.

To date, additives containing alkali metals have been proposed as additives to protect valve seat wear.

For example, U.S. Pat. No. 3,955,938 (Exxon) compositions based on inorganic and organic sodium salts, which are used together with ash-free dispersants as additives in unleaded propellants for valve protection. EP 0 288 296 (BP Chemicals) proposes a fine-grained metal salt dispersion as an additive to prevent valve seat wear, especially a dispersion of potassium borate, sodium borate, potassium carbonate and potassium bicarbonate.

According to EP 0 301 448 (BASF), fuels for preventing or reducing wear phenomena on valves and at the same time reducing corrosion phenomena contain salts of monoamides of dicarboxylic acids having 2 to 4 carbon atoms between carboxyl groups or amides of tricarboxylic or tetracarboxylic acids with alkali metals or alkali metals and the amino nitrogen carries at least one hydrocarbon group optionally substituted by an oxygen atom or an amine. At the same time, these additives are intended to act as detergents to maintain engine cleanliness.

EP-A1-0 307 815 (BASF) relates to propellants containing small amounts of cycloolefins with an anhydride of alkyl vinyl ether copolymers of olefin and / or maleic acid copolymers and / or and / or cycloalkylvinylethers with maleic anhydride and / or alkylvinyl ether copolymers and / or cycloalkyl vinyl ethers and olefins and / or cycloolefins with maleic anhydride, wherein the carboxyl groups are reacted wholly or partially to form alkali metal or alkaline earth metal salts and carboxylic acid residues with alcohols and / or amines to the corresponding ester and / or amide and / or ammonium groups.

EP 0 342 497 (BASF) also discloses the addition of alkyl (meth) acrylates and / or vinyl esters of optionally monoethylenically unsaturated carboxylic acids, wherein the carboxyl groups of the copolymers are reacted wholly or partially with a view to reducing the phenomena of wear on the valves. alkali to form alkali metal salts and the remainder of the acid groups with ammonia and / or amines to the corresponding amide groups and / or ammonium salts.

EP-A1-0 207 560 (Shell) discloses alkali metal and alkaline earth metal salts of hydrocarbon substituted succinic acid as wear protection additives. The hydrocarbon substituents on the α-carbon atom or atoms of this succinic acid have a length of 20 to 200 carbon atoms.

Hydrocarbon-substituted succinic acid derivatives are the subject of extensive older and newer patent literature. Also, imide derivatives of these substances are used because of their dispersing effect alone or in combination with other additives.

In EP-A-233-250 (Lubrizol), combinations of compositions comprising alkali or alkaline earth metals and ashless dispersants are proposed as anti-wear additives for valve seats. Of the alkali metal-containing compositions, only the salts of organic alkylarylsulfonic acids are specifically mentioned herein; the dispersing agents are already known alkenylsuccinimides, which generally contain at least 30 aliphatic hydrocarbon atoms.

PCT patent application WO 91/07477 / (Rechem) relates to improving the ignition capability of fuels and shows this relating to the addition of alkali metal and alkaline earth metal salts of monoesters and diesters of sulfonic acid succinic acid. These compounds are succinic acid derivatives in which the carboxyl group or carboxyl groups are or are esterified with hydrocarbon residues and the α-carbon atom of succinic acid is substituted with a sulfonic acid group. These sulfosuccinic acid esters are present in the form of alkali metal or alkaline earth metal salts.

These groups of compounds are not new to the scientific world. It has previously been suggested to use them as other surfactants as antistatic additives (FR Patent 1 602

314, Mobile

Oil), as a means of suppressing the formation of soot in the exhaust gases of diesel engines or as a means to improve (GB 1 066 878, Shell) combustion behavior, or to obtain cleaner flue gases in internal combustion engines in general (U.S. Patent No. 337 333, Mohnhaupt).

SUMMARY OF THE INVENTION

SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide affordable wear protection additives for unleaded motor gasolines which reduce or even reduce wear on the exhaust side of the engine while maintaining engine cleanliness. In addition, they must also correspond to a variety of tests that are generally common in the art today.

Surprisingly, it has been found that the known salts of succinic acid esters meet these requirements in a particularly good manner. These effects could not be anticipated because at the time of earlier publications the problem of valve seat wear on unleaded gasoline was not known and PCT application WO / 07477 dealt with another task, namely to increase the spark plug performance and increase the burning rate.

Accordingly, the present invention provides novel wear protection additives which comprise a neutral alkali metal and / or alkaline earth metal salt of a monoester or diester of sulfosuccinic acid of the formula I

R ¹ OOC - CH ₂

I M (I)

R ² OOC - ch - with ₃ ^J nt wherein n

R ¹ and R ² independently of one another denote hydrogen or an aliphatic hydrocarbon group with the proviso that no more than one of R ¹ or R ² is hydrogen,

M is an alkali metal or alkaline earth metal ion; and

n represents the valence of metal M.

The aliphatic hydrocarbon groups may be saturated or unsaturated and optionally may carry substituents. Suitable substituents are, for example, hydroxy, ether, ketone, phenyl or ester groups, which may be the same or different on both hydrocarbon groups.

Sulfosuccinic acid monoesters or diesters may be contemplated and the same or different residues may be esterified with respect to the SO ₃ group by an α-carboxyl group or a β-carboxyl group, or both. Sulfosuccinic acid diesters are preferred. They have been shown to be somewhat soluble in gasoline, which makes it possible to use the required amounts of alkali metal or alkaline earth metal salts without problems. The chain length of the aliphatic hydrocarbon groups in the ester moieties is preferably 4 to 20 carbon atoms. Particularly preferred are hydrocarbon radicals having a chain length of 6 to 13 carbon atoms, in particular a chain length of about 8 carbon atoms.

However, it is also possible to use mixtures of said salts.

Alkali metal salts of sulfosuccinic acid esters are preferred, and potassium salts have proven particularly suitable to protect the exhaust valves.

Apart from the excellent wear protection effect, a further surprising effect has been found in the additives according to the present invention, namely a demulsifying effect in the presence of water. As is known, the complete removal of water from gasoline is very difficult to achieve. Condensation effects must practically always take into account the presence of moisture. By their demulsifying effect, the novel additives reduce the disadvantageous effects of such aqueous contamination. The fuel remains clear, the phase boundaries remain sharp and no solids are stored.

Sulfosuccinic acid ester salts also act as a surfactant, facilitating the formation of additive packs for high engine cleanliness requirements. Since the problem of engine contamination and the formation of disturbing deposits on the exhaust valves of modern engines is still of great importance, it is necessary for the additives of the present invention to form them together with detergents. A wide variety of ash-free detergents are suitable, such as long-chain amide-imide compounds, long-chain amines, polyethers or polyetheramines. Polybutynamines in combination with sulfosuccinic acid ester salts have proved to be particularly advantageous. Preferably, the detergents have an average molecular weight of 2000 to 3000.

As already contemplated, the additives of the present invention may also contain other additives known per se. For example, corrosion protection is often required or necessary.

Other parts of all modern additive compositions are the so-called carrier oils. These consist either of mineral oil fractions or of synthetic products such as poly-alpha-olefins. As a rule, they are detergents which are formulated as solutions in carrier oils and are thus incorporated into the additive compositions. In addition, alkali metal components may also be more useful by the addition of a carrier oil component.

If desired, the overall additive compositions may be mixed with a diluent, which may optionally also contain aromatic components, for ease of processing, gasoline solubility and low viscosity at low temperatures. Aromatic kerosenes are preferred for this purpose. With such diluents, viscosity limits of about 800 cP at -20 ° C, which are suitable for European conditions, can be achieved.

The ratio of the amount of the alkali metal component to the detergent is preferably in the range of 1: 8 to 1: 15, and these data refer to detergents which optionally contain a carrier oil.

Depending on the requirements, the additives may contain 15 to 40% by weight, preferably 30 to 40% by weight, of aromatic kerosene as a diluent.

Methods for the production of metal salts of sulphonosuccinic acid monoesters or diesters are already known and are described in GB 446 568, 760 121 or 1 050 578.

Methods for the production of metal salts of sulphonosuccinic acid monoesters or diesters are already known and are described in GB 446 568, 760 121 or 1 050 578.

Gasoline propellant containing an additive according to the present invention meets the requirements therein when it contains 0.01 milligramatom (mVal) to 2.5 milligramatom (mVal) of alkali metal per kilogram of fuel. The preferred range is in the range of 0.02 to 1.0 mVal, particularly in the range of 0.07 to 0.25 mVal of alkali metal per kilogram of fuel.

For the preferred potassium, this means that a potassium content in the range of 0.5 mg to 100 mg per kilogram of fuel is used. A range of 1 mg to 30 mg, in particular 3 mg to 10 mg of potassium per kilogram of fuel is preferred.

i

DETAILED DESCRIPTION OF THE INVENTION

The present invention is explained in more detail below with reference to examples.

additives

The wear protection additive is made of the following components:

The alkali metal component consists of the potassium salt of sulfosuccinic acid dioctyl ester. When used without carrier oil, this component contains about 8.5% potassium by weight.

A polybutamine-based detergent is used as the detergent.

A proportion of the carrier oil is derived from the detergent component, and potassium sulfosuccinate may also be formulated with the carrier oil.

For dilution, the product contains aromatic kerosene.

The mixing ratios in this particular example are as follows:

6.3% by weight 70.4% by weight 23.3% by weight potassium sulfosuccinate components kerosene detergent components.

The potassium content of this additive is about 0.31% by weight.

The additive is added in an amount of 1100 ml to 1000 l of fuel, so that each liter of fuel contains 4 mg of potassium.

Example 1

In order to show the positive effect of the fuel of the present invention on the wear of not specially cured exhaust valves in gasoline engines, a comparative test for 50 hours is performed on the test engine. A commercially available test engine with a gray cast iron cylinder head without specially cured exhaust valve seats is run for 50 hours at high load and high speed, using once unleaded, commercially available, unadulterated fuel according to the present invention. and once the fuel is used with the above-mentioned amount of additive according to the present invention.

At the end of the test, the exhaust valve seats, operated with unleaded fuel without additive, have a recess which results in regular valve clearance adjustment prescribed multiple times from the manufacturer. In operation with unleaded gasoline containing the additive according to the present invention in the above dosing, only a circular recess, which represents the fracture portion of the prescribed valve clearance, can be measured.

Example 2

In order to show that the unleaded fuel with the additive according to the present invention does not affect the invention, even during long-term operation, the negative efficiency of the modern exhaust gas purification system for gasoline engines (lambda-probe;

three-way catalytic converter), a long-term vehicle test with vehicles of the same type lasting 80,000 km was performed. One vehicle with conventional unleaded petrol without additive according to the present invention and one vehicle with additive according to the present controlled invention, in the dosages mentioned above, were operated in road traffic. The efficiency of the cleaning system and the comparison of the emissions of both vehicles were carried out at the start of the test in accordance with the Austrian regulations on exhaust gas typing.

At the end of the in-service test on a vehicle that was operated with unleaded petrol with the additive of the present invention at the above dosage, better emission values were measured than a vehicle that was operated without this additive. The achieved values for the content of carbon dioxide, hydrocarbons and oxides of nitrogen did not significantly reach the limit values stated in the typing regulations.

Example

In accordance with legal requirements, deposits in the intake manifold and intake valves of modern gasoline engines can be influenced by finely tuned blend preparation and the exhaust gas purification system, thereby significantly affecting performance and flue gas emissions.

Throughout Europe 's standardized test procedure (CEC F-05-T-92) with a four-cylinder gasoline engine, the behavior of sediments is evaluated for non-additive and additive petrol.

The additive according to the invention causes the following improvement in this test with respect to the formation of deposits on the intake valves:

Sediment Fuel Test Petrol (Eurosuper) Not Additive 250 to 700 mg / Valve Petrol (Eurosuper) + Additive (1 g / 100Og Petrol) Less than 100 mg / Valve

Claims (15)

1. Additive / unleaded motor gasolines for reducing or preventing wear on valve seats which essentially comprise an alkali metal or alkaline earth metal salt of an organic sulfonic acid and at least one ash-free detergent, and optionally other known additives, characterized by that contain a neutral alkali metal and / or alkaline earth metal monoester or diester of sulfosuccinic acid of the general formula I R ¹ OOC - CH ₂ (I). R ² 00C - CH - with ₃ in which R ¹ and R ² independently of one another denote hydrogen or an aliphatic hydrocarbon group with the proviso that no more than one of R ^1, a hydrogen, M is an alkali metal ion and n represents the valence of metal M. or R ² is a hydrogen or an alkaline earth metal Additives according to claim 1, characterized in that they contain salts of diesters of sulfosuccinic acid. Additives according to claim 1 or 2, characterized in that they contain salts of sulfosuccinic acid esters in which the ester groups consist of hydrocarbon radicals having 4 to 20 carbon atoms. Additive # 1 according to any one of claims 1 to 3, characterized in that they contain salts of sulfosuccinic acid esters in which the ester groups consist of hydrocarbon radicals having 6 to 13 carbon atoms. An additive according to any one of Claims 1 to 4, characterized in that it contains salts of esters of sulphosuccinic acid in which the ester groups consist of hydrocarbon radicals having 8 carbon atoms. An additive according to any one of claims 1 to 5, characterized in that it contains alkali metal salts of sulfosuccinic acid esters. The additive according to claim 6, characterized in that it contains potassium salts of sulfosuccinic acid esters. An additive according to any one of claims 1 to 7, characterized in that it contains a polybuthylamine-based detergent. Additive # / according to one of claims 1 to 7, characterized in that it comprises a polyetheramine-based detergent. The additive according to any one of claims 1 to 9, characterized in that it comprises a detergent having a molecular weight of 2000 to 3000. The additive according to any one of claims 1 to 10, characterized in that it contains a potassium component and a detergent component in a weight ratio of 1: (8-15). An additive according to any one of claims 1 to 11, characterized in that it contains from 4% to 9% by weight of the alkali metal component and from 60% to 9% by weight. 80% by weight of the detergent component; 100% is the carrier oil and / or diluent. ' An additive according to any one of claims 1 to 12, characterized in that it contains 0.2% of potassium «. »Up to 0.7% by weight. IN Unleaded motor gasoline, characterized in that it contains an additive according to any one of claims 1 to 13 in an amount such that from 0.01 mVal to 2.5 mVal, preferably 0.02 mVal to 1, is present per kilogram of fuel. 0mVal, especially 0.07mVal to 0.25mVal of alkali metal. Unleaded motor gasoline according to claim 14, characterized in that it contains 0.5 to 100 mg, preferably 1 to 30 mg, in particular 3 to 10 mg of potassium per kilogram of fuel.