SK280988B6 - Use of neutral salt of sulfosuccinic acid monoester or diester with alkali metals as additive for lead-free motor petrols - Google Patents

Abstract

The use of neutral salt of sulfosuccinic acid monoester or diester with alkali metals in combination with at least one detergent and, if appropriate, with other fuel additives known per se is useful as an anti-wear additive for lead-free motor petrols.

Description

Technical field

The invention relates to the use of neutral salts of an alkali metal monoester or diester of an alkali metal sulfosuccinic acid as additives to unleaded motor gasolines to reduce or prevent wear of valve seats substantially comprising an alkali metal or alkaline earth metal organic sulfonic acid salt and at least one detergent free. ash, as well as any other known additives.

BACKGROUND OF THE INVENTION

The introduction and expansion of unleaded petrol has created the problem that in vehicles that could be operated with leaded gasoline without knocking the engine, the exhaust valves wore dramatically when unleaded gasoline was used.

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

These anti-wear valve protection additives 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.

Alkali-containing additives have hitherto been proposed as additives to protect against valve seat wear.

For example, U.S. Pat. No. 3,955,938 (Exxon) discloses compositions based on inorganic and organic sodium salts that are used together with ash-free dispersants as an additive in lead-free propellant to protect the valves. EP 0 288 296 (BP Chemicals) proposes a fine-grained dispersion of metal salts, in particular a potassium borate, sodium borate, potassium carbonate and potassium bicarbonate dispersion as an additive to valve seat wear.

According to EP 0 301 448 (BASF), the propellants contain, for the prevention or reduction of wear phenomena on the valves and at the same time reduce the corrosion phenomena, salts of monoamides of dicarboxylic acids having 2 to 4 carbon atoms between carboxyl groups or amides of tricarboxylic or tetracarboxylic acids 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 copolymers of olefins and / or cycloolefins with maleic anhydride and / or copolymers of alkyl vinyl ethers and / or cycloalkyl vinyl ethers with maleic anhydride, and / or or copolymers of alkyl vinyl ethers, 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 carboxyl group residues with alcohols and / or amines to the corresponding ester and / or amide groups, and / or ammonium groups.

EP 0 342 497 (BASF) also describes the addition of alkyl (meth) acrylates and / or vinyl esters of optionally monoethylenically unsaturated carboxylic acids, in which the carboxyl groups of the copolymers are reacted wholly or partially with the alkali to reduce the phenomena of corrosion. 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 derivatives of succinic acid 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 containing alkali or alkaline earth metals and ashless dispersants are proposed as anti-wear additives. Of the alkali metal containing compositions, only the organic alkylarylsulfonic acid salts are specifically mentioned; dispersing agents are the aforementioned 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 sulfonosuccinic 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 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 that they be used as other surfactants as antistatic additives (FR Patent 1 602 314, Mobil Oil), as a means to suppress soot formation in diesel exhaust (GB 1 066 878, Shell) or as means for combustion behavior or for obtaining cleaner flue gases in internal combustion engines in general (AT 337 333, Mohnhaupt).

SUMMARY OF THE INVENTION

It is an object of the present invention to provide cost-effective anti-wear additives to 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 sulfosuccinic acid esters meet these requirements in a particularly good way. 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.

It is an object of the present invention to use an alkali metal and / or alkaline earth metal monoester or diester of sulfosuccinic acid with an alkali metal and / or alkaline earth metal of formula (I) r'-OOC-ch ₂

I

R ² OOC - CH - SO ₃

M (I) in which

R ¹ and R ² independently of one another represent hydrogen or an aliphatic hydrocarbon group having 4 to 20 carbon atoms, where at most one of R ¹ or R ² is hydrogen,

M represents an alkali metal or alkaline earth metal ion and n represents the valence of the metal M, in combination with at least one ash-free detergent or other known additives, such as additives to unleaded gasoline to reduce or prevent valve seat wear.

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 mono-esters or diesters may be contemplated and the same or different moieties can 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 to be particularly suitable to protect the exhaust valves.

Apart from the excellent wear protection effect, a further surprising effect, namely a de-emulsifying effect in the presence of water, has been found in the additives of the present invention. As is known, complete removal of water from gasoline is very difficult to achieve. Condensation effects must practically always take into account the presence of moisture. The novel additives, by their demulsifying action, 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, which facilitates the formation of additive packs for high engine purity 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 salt esters have proven to be particularly advantageous. Preferably, the detergents have an average molecular weight of 2000 to 3000.

As already mentioned, the additives of the present invention may additionally contain other known additives. 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 useful for this purpose are preferred. With such diluents, viscosity limits of about 800 cP at -20 ° C, which are suitable for European ratios, can be achieved.

The ratio of the amount of the alkali metal component to the detergent is preferably in the range 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 kerosenes as diluents.

Methods for the production of metal salts of sulfonic succinic 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 imposed therein when it contains 0.01 milligrams (mVal) to 2.5 milligrams (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.

DETAILED DESCRIPTION OF THE INVENTION

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

additive

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 wt. potassium.

A polybutamine-based detergent is used as the detergent.

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

The product contains aromatic kerosene for dilution.

The mixing ratios in this particular example are as follows:

6.3 wt. a potassium sulfosuccinate component,

SK 280988 Β6

70.4 wt. detergent component,

23.3 wt. kerosene.

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 4 mg of potassium are contained in each liter of fuel.

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 is performed on the test engine for 50 hours. 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 the unleaded, commercially available, fuel-free fuel of the present invention and once using the fuel with the indicated 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 that 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 said metering, only a circular recess, which represents the fracture portion of the prescribed valve clearance, can be measured.

Example 2

To show that unleaded fuel with the additive of the present invention also does not adversely affect the efficiency of a modern exhaust gas purification system for gasoline engines (lambda-probe; three-way catalytic converter) during long-term operation, a long-term vehicle test of 80,000 km . In this process, one vehicle with unleaded petrol customary on the market was operated without an additive according to the present invention and one vehicle with an additive according to the present invention, at the dosages mentioned above, in controlled 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 with a vehicle that was operated with unleaded gasoline with the additive of the present invention at the indicated dosage, better emission values were measured than a vehicle that was operated without that additive. The achieved levels of carbon dioxide, hydrocarbons and oxides of nitrogen did not significantly exceed the limit values stated in the typing regulations.

Example 3

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 the Europe 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:

Test fuel deposits _ petrol (Euroeupet) 250 to 700 mg / valve petrol (Euroauper) + additive (1 g / 1000g of gasoline) less than 100mg

Claims (13)

PATENT CLAIMS 1. The use of the neutral salt of a monoester or a diester of sulfosuccinic acid, alkali and / or earth metal aíkalických of formula (I) lúooc - _CH2 I R ² OOC - ch - with ₃ in which R ¹ and R ² independently of one another represent hydrogen or an aliphatic hydrocarbon group having 4 to 20 carbon atoms, where at most one of R ^1, optionally R ² represents hydrogen, M is an alkali metal or alkaline earth metal ion, and n is the patronage of metal M, in combination with at least one ash-free detergent, or other known additives, such as additives to unleaded gasoline to reduce or prevent valve seat wear. Use of a sulfosuccinic acid diester of the general formula (I) for the purpose mentioned in claim 1. Use of a sulfosuccinic acid ester salt of the general formula (I), in which the ester groups consist of hydrocarbon radicals having 4 to 20 carbon atoms in combination with an ash-free detergent, for the purpose mentioned in claim 1. Use of a sulfosuccinic acid ester salt of the general formula (I) in which the ester groups consist of hydrocarbon radicals having 6 to 13 carbon atoms in combination with an ash-free detergent for the purpose mentioned in claim 1. Use of a sulfosuccinic acid ester salt of the general formula (I), in which the ester groups consist of hydrocarbon radicals of 8 carbon atoms in combination with an ash-free detergent, for the purpose mentioned in claim 1. Use of an alkali metal sulfosuccinic acid ester salt of formula (I) in combination with an ash-free detergent for the purpose set forth in claim 1. Use of a potassium salt of a sulfosuccinic acid ester of formula (I) in combination with an ash-free detergent for the purpose set forth in claim 1. Use of an alkali metal and / or alkaline earth metal sulfosuccinic acid ester salt of formula (I) in combination with a polybutamine-based detergent for the purpose set forth in claim 1. Use of an alkali metal and / or alkaline earth metal sulfosuccinic acid ester salt of formula (I) in combination with a polyetheramine-based detergent for the purpose set forth in claim 1. SK 280988 Β6 Use of an alkali metal and / or alkaline earth metal sulfosuccinic acid ester salt of formula (I) in combination with an ash-free detergent having a molecular weight of 2000 to 3000 for the purpose set forth in claim 1. Use of a potassium salt of a sulfosuccinic acid ester of formula (I) in combination with an ash-free detergent in a weight ratio of 1: 8 to 15 for the purpose set forth in claim 1. 12. Use of a 4 wt. % to 9 wt. % of an alkali metal sulfosuccinic acid ester salt of formula (I) and 60 wt. % to 80 wt. % ash-free detergent; represents a carrier oil and / or diluent for the purpose set forth in claim 1. Use of a mixture of the alkali metal sulphosuccinic acid ester salt of the formula (I) and an ash-free detergent, wherein the potassium is present in an amount of 0.2% by weight. % to 0.7 wt.%, for the purpose set forth in claim 1.