SK278437B6 - Derivatives of dicarboxyl acids as additives to the low-lead or lead-less motor fuel - Google Patents

Abstract

This patent describes the derivatives of dicarboxyl acids playing role of additives to the motor fuel for cars containing a small or no quantities of lead, an acting of which enables to prevent an abrasion of clack seats closed to the exhausts in cars not prepared for consumption of motor fuel containing small or no quantities of lead. The above mentioned derivatives are of the structural chemical formula (I), however the meaning of the concrete individual symbols is explained in the description

Description

Technical field

The present invention relates to dicarboxylic acid derivatives as additives to low-lead or unleaded motor gasolines, which prevent the wear of the exhaust valve seats of vehicles not designed for combustion of unleaded automotive gas.

BACKGROUND OF THE INVENTION

The trend towards the use of unleaded gasoline is significant worldwide as a result of efforts towards a healthier environment. They started production of 15 unleaded gasoline in the USA in the early seventies. In Japan, unleaded petrol started to be produced in 1974 and in Europe in early 1984. Since then, its share in the production and consumption of gasoline has been on a steep upward trend. The global trend is thus clearly directed towards the production and use of unleaded gasoline. For example, in Japan, only unleaded gasoline has been used exclusively since March 1986 (Chem. Econ. And Eng. Rev., 9, 25 (1986);

Chem. Ind., 7, 750 (1986)). In the US, their share of the total 25 production in 1990 was over 90% and in the early 1990s it is considered to completely exclude the production of leaded petrol. In Europe, given the time lag and the diversity of the car fleet and the technical capabilities of the refineries, the situation is not as clear as it is overseas. Unleaded petrol is finding its place on the market in different countries differently quickly.

In developed European countries, the share of unleaded petrol production in total petrol production is currently around 50%. The total production of unleaded petrol is estimated to be at least 75% in 1995 (Oil and Gas Journal, 88, 4, 11 (1990); Erdol und Kohle, 3, 119 (1988)) compared to 21.3% in 1986 and 26% in 1987 (Oil and Gas Journal, 85, 14, 15 (1987);

Petrole et Techniques, 38, 316 (1986)). Lead-free petrol has been produced and sold in Czechoslovakia since 1986. In 1990, its share in total petrol production did not exceed 3%.

The production and distribution of unleaded gasoline from the outset encounters a major problem, which, together with the refinery's technical capabilities, is a major brake on the immediate transition to the production and use of unleaded fuel only. This problem is the impossibility of burning unleaded gasoline in cars designed for leaded fuel. The combustion of unleaded benzine in such cars results in damage to the cylinder head of the engine and the engine itself and decommissioning of the car (Bratský, D., Oravkin, J .: Production of gasoline in Czechoslovakia at the turn of the millennium, 33rd Oil Conference, Bratislava Bratrsky, D., Fehér, P., Oravkin, J., Málach, V .: Trend of the development in the field of automotive gasoline and its additives, Study VÚRUP, Bratislava, 1990; Petrole et Techniques, 60 , 326 (1986); Automotive Engineering, 95, 11, 72 (1987); Hydrocarbon Processing, 68, 7, 11 (1989); Grill, 60 RA; Landells, RGM: Reduction of Gasoline Lead and Its Effect on Valve seat recession: the problem and its solution., Proceedings of the 33rd Conference on Oil with Foreign Participation, Bratislava, 1988). Essentially, this is an old-fashioned problem encountered by car manufacturers 65 in the early 1920s, which was resolved when the lead-based anti-knockers were added to gasoline. The number of cars at risk of burning unleaded gasoline was estimated to be 70 million worldwide by 1987 (Automotive Engineering, 95, 11, 72 (1987)), of which approximately 7 million in the UK (Hydrocarbon Processing, 68, 7, 17). In the CSFR, the number of cars unable to use unleaded fuel is estimated to be around 70% of the total number of passenger cars, and due to the statistically found five percent replacement of passenger cars in the CSFR per year, their complete disappearance is expected around 2010 (Bratský, D). ., Oravkin, J .: Production of Car Gasoline in Czechoslovakia at the Turn of the Millennium, 33rd Conference on Rope, Bratislava, 1988. Bratský, D., Fehér, P., Oravkin, J., Málach, V .: Trend in the Development of Automotive gasoline and additives to them (Study, VURUP, Bratislava, 1990).

Almost all cars manufactured by 1971 belong to this group of cars (Automotive Engineering, 95, 11, 72 (1987)). On the other hand, most automakers, since 1986, have been producing models capable of burning unleaded petrol (Autozeitung, 20, 67 (1989); Autozeitung, 21, 66 (1989)).

The cause of engine failures in the combustion of unleaded fuel in these cars is the quality of the material from which the exhaust valve seats, respectively. the entire cylinder head. If these are of cast iron or other similarly soft material, they burn quickly and wear when unleaded gasoline is burned. As a result, the exhaust valves become more and more recessed into the cylinder head of the engine and the valve clearance is thereby constantly reduced. The final stage of this process is the imperfect closure of the combustion chamber, loss of compression and engine power, burning of exhaust valves and their seats. Finally, the engine cylinder head is destroyed (Automotive Engineering, 95, 11, 72 (1987); Grill, RA: Landells, RGM: The Reduction of Gasoline Lead and Its Effect on Valve Seat Recession: The Problem and Its Solution.) of the 33rd Oil Conference with Foreign Participation, Bratislava, 1988).

The degree and speed of the recess of the exhaust valve seats depends on the design and operating parameters of the car. In addition to the hardness of the seat material, the design parameters include valve rotation, spring tension, seat angle and width, operating temperatures and valve geometry. The most important of the operating parameters are the engine speed, its load and the richness of the fuel-air mixture. Valve rotation, high speed and engine load, and lean mixes have a drastic effect on exhaust valve seat burying (Automotive Engineering, 95, 11, 72 (1987); Grill, RA; Landells, RGM: The Reduction of Lead in Gasoline and Its Effect) on the valve seat recession: the problem and its effect on the valve seat recession: the problem and its solution., Proceedings of the 33rd Conference on Oil with Foreign Participation, Bratislava, 1988).

Practically only in the twilight of the use of lead compounds in gasoline, it became apparent that, in addition to increasing the detonation stability, lead in gasoline performed another very important function of protecting the exhaust valve seats from mechanical wear during engine operation. It is believed that lead combustor combustion products form a thin protective film on the valve seat surfaces, preventing high temperature oxidation and abrasion, and reducing adhesion and material transfer, thereby protecting them from unwanted wear (Automotive Engineering, 95, 111,72 (1987)).

The solution to the problem that would lead to the use of unleaded fuel in this endangered group of cars is to:

(a) replacement of the cylinder heads of such vehicles with heads with specially cured exhaust valve seats; which is virtually impossible and financially unacceptable to consumers due to many types of run-out.

(b) the addition to lead-free petrol of a harmless additive to catalytic converters that would replace the film-forming function of lead compounds and provide the exhaust valve seats with the necessary protection. Only two types of ingredients of this designation are currently offered on the world market. Although functionally relatively satisfactory for several foreign engines, ŠKODA engines could not provide effective protection against the bore of their exhaust seats, even at several times higher dozing than recommended by the manufacturer (Bratský,

D., Fehér, P., Oravkin, J., Málach, V .: Trend in the Development of Automotive Gasoline and Additives. Study. VURUP, Bratislava, 1990).

Another option is to use leaded petrol until such vehicles are represented in the fleet, but this makes it possible that only unleaded petrol can be produced and used, with the consequent negative impact on the environment.

SUMMARY OF THE INVENTION

The most preferred solution to this situation is to use unleaded gasolines containing the dicarboxylic acid derivatives of the present invention. Their addition ensures that the combustion of completely unleaded or low-leaded gasoline does not damage the exhaust valve seats made of non-hardened materials of various types, such as cast iron. The additives based on the dicarboxylic acid derivatives described in the present invention are harmless to health and harmless to catalytic exhaust gas converters.

The dicarboxylic acid derivatives according to the invention have the structural chemical formula (I):

coox \ / ¹ ¾ (I), 'CO - Y in which means

R, a divalent hydrocarbon function or a hydrocarbon function having nitrogen atoms in the amino group and / or oxygen atoms in the hydroxy and / or ether group having a total number of carbon atoms of from 1 to 38,

R is a monovalent hydrocarbon function having from 1 to 42 carbon atoms or hydrogen,

X hydrogen and / or an alkali metal and / or alkaline earth metal group,

Y oxygen or nitrogen, a and b integers zero or 1, where a + b ä 1,

R _{3 is} hydrogen or a monovalent hydroxy-substituted hydrocarbon function having a carbon number of 1 to 42, or a monovalent hydrocarbon function having a carbon number of 1 to 42, or a monovalent function having a structural chemical formula (II) or (III), or ( IV)

- [- (CH ₂ ) _c -NH-] _d -R 4 (II)

- (- CH ₂ -CH-O-) _e -R ₂ (III) r ₅

- (- CH-CH ₂ -O-) _e ., - CH-CH ₂ - [- NH- (CH ₂ ) _c -] _d -NR ₂ (IV),

R ₅ R _{5 with} R ₅ in which R is

R4 is hydrogen or a monovalent hydrocarbon functional group having a carbon number of 1 to 42 or a functional group having a structural chemical formula (III),

R _{5 is} hydrogen or a monovalent hydrocarbon function having a carbon number of 1 to 3,

R 5 is hydrogen or - (- CH-CH ₂ -O-) fH,

Rs c an integer from 1 to 10, d an integer from zero to 6, e an integer from 1 to 50, f an integer from 1 to 50.

Such dicarboxylic acid derivatives, applied to unleaded automotive gasoline, are effective inhibitors of the wear of the exhaust valve seats of cars not designed to burn unleaded gasoline and thus allow their continuous, trouble-free operation on this fuel.

In order to improve handling, in particular viscosity and hence pumpability at the stage of packaging, transport and application, the dicarboxylic acid derivatives as an additive to the gasoline according to the invention may also contain an auxiliary component which is an organic solvent, preferably of the aromatic type. Suitable solvent types are toluene, xylene, aromatic hydrocarbons having from 9 to 13 carbon atoms in the molecule, or technical mixtures thereof, such as the naphtha reformate, the reformate fraction boiling in the range of 75 ° C to 250 ° C, the pyrobenzine fraction with a similar distillation range. The aromatic hydrocarbon content of these mixtures is generally above 25% by weight.

To provide the claimed effects of the dicarboxylic acid additives of the invention, these are added to the gasoline at a concentration of from 0.025 to 1.1% by weight. If the additive according to the invention also contains an auxiliary component which is already an specified organic solvent, the resulting addition of the additive to the autobenzine is chosen so that the concentration of the active ingredient is within the stated range.

In order to improve pumpability and also to maintain the required content in automotive gasoline, the additive according to the invention may be further diluted either directly with the gasoline, some of its components or with another hydrocarbon solvent before it is added to the gasoline.

The additive according to the invention can be added to the gasoline either directly at the stage of preparation of the gasoline at the refinery (primary addition) or it can be added to the finished gasoline at the stage of its refining.

276 consumption or distribution, for example at service stations (secondary allowance). The secondary addition of the additive according to the invention is particularly advantageous in those cases where the gasoline is produced without its content. 5

DETAILED DESCRIPTION OF THE INVENTION

The following examples illustrate the advantages and practical use of the specified dicarboxylic acids as additive to the gasoline of the invention, but without limiting the scope of the invention in any way.

Example 1

A 4-cylinder Škoda petrol engine with a cylinder capacity of 1174 cm ³ with a cast-iron cylinder head was subjected to an engine test under the conditions of Table 1, using a total of 20 unleaded petrol (0.0000 g Pb / 1) with an octane rating of 96 and 87 by the motor method, as well as unleaded gasoline containing a lead concentration for unleaded gasoline, i.e. 0.013 g Pb / l of the same octane level. During the test, the valve clearance was measured every 6 hours and adjusted if necessary so that its minimum value was not less than 0.2 mm. At the end of the 36-hour engine test, the engine cylinder head was removed from the intake and exhaust valves. After detecting 30 changes in the valve weights, the total depression of the exhaust valve seats was measured. The results obtained are shown in Tables 2 and 3, in which the individual values represent both the size of the average recess of the 4 rolls and the values for one, the most recessed roll. The results of the test showed that the use of unleaded gasoline in engines of this type is not possible.

A similar test was also performed with said totally unleaded autobenzine (0.0000 g Pb / l) but containing 850 ppm of the dicarboxylic acid derivative 40 of the invention with chemical structural formula (I), wherein:

X is Ca ^{2 + / 2} , Y is nitrogen, R ₂ is hydrogen, a = 1, b = 1,45

R ₃ is - [- (CH ₂ ) _c -NH-] _d -R 4 wherein c = 2, d = 2 and

R 4 is polypropenyl with an average molecular weight of 450 g / mol.

The dicarboxylic acid derivative was prepared by reacting phthalic anhydride with N-polypropenyl-diethylene-50 triamine and then neutralizing the resulting phthalic acid derivative with calcium oxide.

The results of this test showed that no exhaust valve seats were recessed in any of the engine cylinders, even when the test duration was extended to 55 56 hours (average change in the valve clearance of the exhaust valves was -0.0075 mm, maximum measured value -0, 04 mm).

Example 2 60

A long-term engine service life test (300 hours) under conditions according to ČSN 30 0506 was performed on a four-cylinder petrol engine of the Škoda type Š 742.13 with a cast-iron cylinder head using conditions of unleaded petrol with octane number 65 96 by research method and 87 engine method. g Pb / l). The fuel used was saturated with 700 ppm of an additive according to the invention with structural chemical formula (I) wherein

R 1 is -CH ₂ -CH-, X is sodium, Y is oxygen, and is zero,

C. 2 'b = 1, R ₃ is - (- CH-CH ₂ -O-) _e . _{R-CH-CH 2} -NC ₁₄ H _29,

CH ₃ CH ₃ R e where e = 3 to 5 and R ₆ is - (- CH ₂ -CH-O-) _r H

CH ₃ wherein f = 1 to 3.

The dicarboxylic acid derivative was prepared by reacting tetrapropenyl succinic anhydride with propoxylated tetradecylamine and subsequent neutralization of the resulting intermediate with sodium hydroxide.

The additive of this composition was dissolved in the naphtha reformate prior to addition to unleaded autobenzine so that the resulting solution contained 50% active ingredient.

The results of this test showed that no exhaust valve seats were recessed in any of the engine cylinders (average change in valve clearance of the exhaust valves was 0.055 mm). Unleaded gasoline containing said additive according to the invention fully protected the exhaust valve seats of the used engine, while not compromising any of its monitored operating parameters and reducing its overall service life.

Example 3

Road motor tests of 50,000 to 80,000 kilometers were carried out on the fleet presented in Table 4. New engines, carburetors, fuel tanks and intake manifolds were used in cars. Unleaded autobenzine (0.001 - 0.005 g Pb / l) with an octane number of 95 to 97 and a methyl tert-butyl ether content of 7 to 12% by volume, which was additivated with 750 ppm of the dicarboxylic acid derivative according to the invention with the structural formula I, in which

R 1 is -CH = CH-, X is sodium, Y is nitrogen, R ₂ is phenyl-, a = 1, b = 1, R ₃ is C ₁₂ H 25 -.

The dicarboxylic acid derivative was prepared by reacting the corresponding secondary amine with maleic anhydride followed by neutralization of the resulting intermediate with sodium hydroxide.

The additive of this composition was dissolved in an aromatic solvent boiling from 140 to 190 ° C prior to addition to unleaded autobenzine such that the resulting solution contained 10% active ingredient.

All vehicles were driven mostly in urban and highway traffic during the tests. After every 5000 km, the clearance of the exhaust valves was checked, and the vehicle's performance and emission characteristics, as well as their fuel economy and octane demand, were measured every 10,000 km. The efficiency of vehicles with catalytic converters has been determined. After completion of the tests, the engines were dismantled and evaluated in a comprehensive manner.

The evaluations have shown that the additive according to the invention provides the exhaust valve seats of all test vehicles with perfect protection against their wear during the combustion of unleaded petrol. The additive does not adversely affect any function of the petrol engine or its service life. It is harmless to catalytic exhaust aftertreatment systems and does not degrade petrol engine emissions.

Table 1

Opinion engine test conditions

phase Test cycle composition duration [Min] Engine speed [l.min ¹ ] Engine load First 20 3000 full Second 10 850 idle Third 20 5000 full 4th 10 850 idle

Table 2

Effect of test duration on exhaust valve seat recesses using lead-free petrol (0,000 g Pb / 1) and additive-free according to the invention

Number of hours Exhaust valve seat recess [mm] diameter for 4 cylinders one cylinder max. 12 0.26 0.35 24 0.45 0.60 36 0.80 1.19

Table 3

Effect of test duration on exhaust valve seat recesses using 0.013 g Pb / l of lead-free petrol and additive-free according to the invention

Number of hours Exhaust valve seat recess [mm] diameter for 4 cylinders one cylinder max. 12 0.12 0.23 24 0.32 0.54 36 0.43 0.76

Table 4

Car fleet used for road motor tests

Vehicle type Ί Number of vehicles ŠKODA 120 L 3 ŠKODA 130 L 8 ŠKODA FAVORIT 136 L with catalytic converter 4 VOLGA GAZ24.10 2 OLTCIT 11 R 3

Industrial usability

The application of the dicarboxylic acid derivatives according to the invention to unleaded gasoline permits the continuous trouble-free operation of all petrol-engined cars on this more environmentally-friendly fuel and thus allows virtually instantaneous transition from leaded gasoline to the production and use of unleaded fuel only.

Claims (1)

PATENT CLAIMS Dicarboxylic acid derivatives as additives to low-lead or unleaded motor spirit, which prevent wear on the exhaust valve seats of vehicles not designed for the combustion of unleaded petrol, characterized by having a structural chemical formula (I): coox ( ^R 2 ⁾ and (I), 'CO-Y X’b in which it means R 1 is a divalent hydrocarbon function or a hydrocarbon function having nitrogen atoms in the amino group and / or oxygen atoms in the hydroxy and / or ether group having a total number of carbon atoms of from 1 to 38, _R2 monovalent hydrocarbon functional group with a carbon number 1 to 42 or hydrogen, X hydrogen and / or an alkali metal and / or alkaline earth metal group, Y oxygen or nitrogen, a and b integers zero or 1, with a + b> 1, R _{3 is} hydrogen or a monovalent hydroxy-substituted hydrocarbon function having a carbon number of 1 to 42, or a monovalent hydrocarbon function having a carbon number of 1 to 42, or a monovalent function having a structural chemical formula (II) or (III), or ( IV) - [- (CHA-NH-R a, (II) - (- CH ₂ -CH-O-) _e -R ₂ (III) R _s - (- CH-CH ₂ -O-) _e ., - CH-CH ₂ - [- NH- (CH ₂ ) _c -] _d -NR ₂ (IV), R ₅ R _{5 with} R ₅ in which is R4 is hydrogen or a monovalent hydrocarbon functional group having a carbon number of 1 to 42 or a structural chemical formula (III), R _{5 is} hydrogen or a monovalent hydrocarbon function having a carbon number of 1 to 3, R 5 is hydrogen or - (- CH-CH ₂ -O-) fH, Rs c an integer from 1 to 10, d an integer from zero to 6, e an integer from 1 to 50, f an integer from 1 to 50.