COMPOSITION AND METHODS AND USES RELATING THERETO

Abstract

A quaternary ammonium salt of formula (I): (I) where in X is a linking group; Y is O, NH or NR.sup.1 wherein R.sup.1is H or an optionally substituted hydrocarbyl group; Q.sup. is a moiety that includes a quaternary ammoniumcation; A.sup. is an anion; R.sup.2 is an optionally substituted alkylene group; R.sup.3 is hydrogen or an optionally substituted hydrocarbyl group; and n is 0 or a positive integer; provided that n is not 0 when R.sup.3 is hydrogen.

##STR00001##

Claims

1. (canceled)

2. A composition comprising a diesel fuel and a quaternary ammonium salt of formula (I): ##STR00013## wherein X is a linking group; Y is O, NH or NR.sup.1 wherein R.sup.1 is H or an optionally substituted hydrocarbyl group; Q.sup.+ is a moiety that includes a quaternary ammonium cation; A.sup. is an anion; R.sup.2 is an optionally substituted alkylene group; R.sup.3 is hydrogen or an optionally substituted hydrocarbyl group; and n is 0 or a positive integer; provided that n is not 0 when R.sup.3 is hydrogen.

3. (canceled)

4. A method of improving the performance of an engine, the method comprising combusting in the engine a diesel fuel composition comprising as an additive a quaternary ammonium salt of formula (I): ##STR00014## wherein X is a linking group; Y is O, NH or NR.sup.1 wherein R.sup.1 is H or an optionally substituted hydrocarbyl group; Q.sup.+ is a moiety that includes a quaternary ammonium cation; A.sup. is an anion; R.sup.2 is an optionally substituted alkylene group; R.sup.3 is hydrogen or an optionally substituted hydrocarbyl group; and n is 0 or a positive integer; provided n is not 0 when R.sup.3 is hydrogen.

5. The salt, composition according to claim 2 wherein the quaternary ammonium salt additive is prepared by reacting: (a) a hydrocarbyl substituted dicarboxylic acid or anhydride thereof; with (b) an alcohol of formula R.sup.3(OR.sup.2).sub.nOH; (c) a reactive alcohol or amine including a tertiary amino group; and (d) a quaternising agent.

6. The composition according to claim 2 wherein X is an optionally substituted alkylene or arylene and R.sup.4 is an optionally substituted hydrocarbyl group.

7. The composition according to claim 2 wherein n is 0 and R.sup.3 is an optionally substituted alkyl or alkenyl group having 4 to 40 carbon atoms.

8. The composition according to claim 2 wherein each R.sup.2 is ethylene or propylene.

9. The composition according to claim 8 wherein R.sup.3 is hydrogen and n is at least 1.

10. The composition according to claim 8 wherein R.sup.3 is an optionally substituted alkyl group having 4 to 40 carbon atoms and n is from 1 to 40.

11. The composition according to claim 2 wherein Q.sup.+ is a group having the formula: ##STR00015## wherein R.sup.5 is an optionally substituted alkylene, arylene or alkenylene group and each of R.sup.6, R.sup.7 and R.sup.8 is independently an optionally substituted hydrocarbyl group.

12. The composition according to claim 11 wherein R.sup.5 is an optionally substituted alkylene group having 1 to 6 carbon atoms, R.sup.6 is C.sub.1 to C.sub.6 alkyl, R.sup.7 is C.sub.1 to C.sub.6 alkyl and R.sup.8 is an unsubstituted C.sub.1 to C.sub.6 alkyl group or a hydroxy substituted C.sub.1 to C.sub.40 alkyl group.

13. The composition according to claim 2 wherein A.sup. is a carboxylate anion.

14. (canceled)

15. The composition according to claim 2 wherein the quaternary ammonium salt additive is prepared by reacting: (a) an optionally substituted succinic acid or anhydride thereof; (b) an alcohol of formula H(OR.sup.2).sub.nOH or R.sup.3OH; (c) a reactive alcohol including a tertiary amino group; and (d) a quaternising agent.

16. The composition according to claim 2 wherein the quaternary ammonium salt additive is prepared by reacting: (a) a succinic acid or anhydride thereof substituted with a C.sub.20 to C.sub.24 alkyl or alkenyl group; (b) a polypropylene glycol or butanol; (c) dimethylaminopropanol; and (d) a quaternising agent selected from the group consisting of: methyl salicylate, dimethyl oxalate and a hydrocarbyl epoxide in combination with an acid.

17. (canceled)

18. The composition according to claim 2 wherein the diesel fuel composition comprises one or more further detergents selected from the group consisting of: (i) a quaternary ammonium salt additive; (ii) the product of a Mannich reaction between an aldehyde, an amine and an optionally substituted phenol; (iii) the reaction product of a carboxylic acid-derived acylating agent and an amine; (iv) the reaction product of a carboxylic acid-derived acylating agent and hydrazine; (v) a salt formed by the reaction of a carboxylic acid with di-n-butylamine or tri-n-butylamine; (vi) the reaction product of a hydrocarbyl-substituted dicarboxylic acid or anhydride and an amine compound or salt which product comprises at least one amino triazole group; and (vii) a substituted polyaromatic detergent additive.

19. The composition according to claim 2 wherein the diesel fuel composition comprises a mixture of two or more quarternary ammonium salt additives.

20. (canceled)

21. The method according to claim 4 wherein the engine is a modern diesel engine having a high pressure fuel system.

22. The method according to claim 4 which achieves keep clean performance.

23. The method according to claim 4 which achieves clean up performance.

24. The method according to claim 4 wherein the deposits are injector deposits.

25. The method according to claim 24 wherein the deposits are internal diesel injector deposits.

26. The method according to claim 4 which achieves an improvement in performance of one or more of: a reduction in power loss of the engine; a reduction in external diesel injector deposits; a reduction in internal diesel injector deposits; an improvement in fuel economy; a reduction in fuel filter deposits; a reduction in emissions; and an increase in maintenance intervals.

27. The method according to claim 26 which provides an improvement in performance in modern diesel engines having a high pressure fuel system and provides an improvement in performance in traditional diesel engines.

28. (canceled)

29. composition according to claim 2 which further comprises one or more further additives selected from the group consisting of: lubricity improvers, corrosion inhibitors and cold flow improvers.

30. (canceled)

Description

EXAMPLE 1

[0427] Additive Al, an additive of the invention was prepared as follows:

[0428] A mixture of alkenes having 20 to 24 carbon atoms was heated with 1.2 molar equivalents of maleic anhydride. On completion of the reaction excess maleic anhydride was removed by distillation. The anhydride value of the substituted succinic anhydride product was measured as 2.591 mmolg.sup.1.

[0429] This product was then heated with one molar equivalent of polypropylene glycol having a number average molecular weight of 425, and the reaction was monitored by FTIR.

[0430] The resultant material was reacted with one molar equivalent dimethyl aminopropanol at 140 C. in xylene and the reaction monitored until constant acid valve and FTIR spectra were obtained. Volatiles were then removed in vacuo to afford a mixed diester.

[0431] This mixed diester product was reacted with 1.5 molar equivalents of butylene oxide, 6 molar equivalents of water and one molar equivalents of acetic acid at 60 C. in toluene for 6 hours. Volatiles were removed in vacuo to provide the quaternary ammonium salt A1.

[0432] Additive A2 was prepared using a method analogous to that used to prepare additive A1 except that tripropylene glycol was used in place of polypropylene glycol.

[0433] Additive A3 was prepared using a method analogous to that used to prepare additive A1 except that polyethylene glycol having a number average molecular weight of 400 was used in place of the polypropylene glycol.

[0434] Additive A4 was prepared using a method analogue to that used to prepare additive A1 except that in the last step the diester was reacted with one molar equivalent of dimethyl oxalate in place of the butylene oxide/acetic acid.

[0435] Additive A5 was prepared using a method analogous to the preparation of additive A2 except in the last step the diester was reacted with one molar equivalent of dimethyl oxalate in place of the butylene oxide/acetic acid.

[0436] Additive A6 was prepared using a method analogous to that used in the preparation of additive A3 except in the last step the diester was reacted with one molar equivalent of dimethyl oxalate in place of the butylene oxide/acetic acid.

[0437] Additive A7 was prepared using a method analogous to that used to prepare additive A1 except that in the last step 1 molar equivalent of methyl salicylate was used as the quaternising agent.

[0438] Additive A8 was prepared using a method analogous to the preparation of additive A2 except that in the last step 1 molar equivalents of methyl salicylate was used as the quaternising agent.

[0439] Additive A9 was prepared using a method analogous to that used in the preparation of additive A3 except that in the last step 1 molar equivalents of methyl salicylate was used as the quaternising agent.

[0440] The reagents used in the preparation of additives Al to A9 are summarised in the table below and further additives prepared from polyisobutenyl substituted succinic acid derivatives and other amines, alcohols and quaternising agents are also listed in table 1. Compounds A10 to

[0441] A15 were prepared by methods analogous to those described in relation to compounds A1 to A9.

TABLE-US-00001 TABLE 1 Exam- Succinic ple anhydride Quaternising No substituent Alcohol Amine agent A1 C20-24 Poly(propylene N,N- Butylene oxide + glycol) Mn425 dimethylamino acetic acid propanol A2 C20-24 Poly(propylene N,N- Butylene oxide + glycol) Mn425 dimethylamino acetic acid propanol A3 C20-24 Poly(ethylene N,N- Butylene oxide + glycol) Mn400 dimethylamino acetic acid propanol A4 C20-24 Poly(propylene N,N- Dimethyl oxalate glycol) Mn425 dimethylamino propanol A5 C20-24 tri(propylene N,N- Dimethyl oxalate glycol) dimethylamino propanol A6 C20-24 Poly(ethylene N,N- Dimethyl oxalate glycol) Mn400 dimethylamino propanol A7 C20-24 Poly(propylene N,N- Methyl Salicylate glycol) Mn425 dimethylamino propanol A8 C20-24 tri(propylene N,N- Methyl Salicylate glycol) dimethylamino propanol A9 C20-24 Poly(ethylene N,N- Methyl Salicylate glycol) Mn400 dimethylamino propanol A10 1000PIB Poly(ethlylene N,N- Methyl Salicylate glycol) 600 dimethylamino propylamine A11 1000PIB Tri- N,N- 1,2- decanol(PO).sub.15 dimethylamino epoxydodecane + propanol acetic acid A12 1000PIB Poly(propylene N,N- Butylene oxide + glycol) Mn425 dimethylamino acetic acid propanol A13 1000PIB Tri- N,N- Styrene oxide + decanol(PO).sub.15 dimethylamino acetic acid propanol A14 550PIB tri(propylene N,N- Methyl Salicylate glycol) dimethylamino propanol A15 1000PIB tri(propylene N,N- Methyl Salicylate glycol) dimethylamino propanol Tridecanol(PO).sub.15 is the reaction product of a C.sub.13 alkanol and an average of 15 moles of propylene oxide per molecule.

EXAMPLE 2

[0442] Diesel fuel compositions were prepared by dosing additives to aliquots all drawn from a common batch of RFO6 base fuel, as detailed in table 1.

[0443] The compositions were tested in a screening test which correlates with performance at combatting IDIDs as measured in the DW10C test.

[0444] In this test a fuel composition is tested using a Jet Fuel Thermal Oxidation Test equipment. In this modified test 800 ml of fuel is flowed over a heated tube at pressures of approximately 540 psi. The test duration is 2.5 hours. At the end of the test the amount of deposit obtained on the tube is compared to a reference value.

[0445] The value shown in table 2 is the percentage reduction in deposit thickness compared to base fuel.

TABLE-US-00002 TABLE 2 Average thickness Compound ppm active (% reduction) A2 (inventive) 120 64 A5 (inventive) 120 80 A14 (inventive) 120 70 C1 (comparative) 120 0 C2 (comparative) 120 2

[0446] Comparative additive Cl is dodecenyl substituted succinic acid.

[0447] Comparative additive C2 is a polyisobutenyl (PIB) substituted succinic acid where PIB has a number average molecular weight of 1000.

[0448] Table 3 below shows the specification for RF06 base fuel.

TABLE-US-00003 TABLE 3 Limits Property Units Min Max Method Cetane Number 52.0 54.0 EN ISO 5165 Density at 15 C. kg/m.sup.3 833 837 EN ISO 3675 Distillation 50% v/v Point C. 245 95% v/v Point C. 345 350 FBP C. 370 Flash Point C. 55 EN 22719 Cold Filter Plugging C. 5 EN 116 Point Viscosity at 40 C. mm.sup.2/sec 2.3 3.3 EN ISO 3104 Polycyclic Aromatic % m/m 3.0 6.0 IP 391 Hydrocarbons Sulphur Content mg/kg 10 ASTM D 5453 Copper Corrosion 1 EN ISO 2160 Conradson Carbon % m/m 0.2 EN ISO 10370 Residue on 10% Dist. Residue Ash Content % m/m 0.01 EN ISO 6245 Water Content % m/m 0.02 EN ISO 12937 Neutralisation (Strong mg KOH/g 0.02 ASTM D 974 Acid) Number Oxidation Stability mg/mL 0.025 EN ISO 12205 HFRR (WSD1, 4) m 400 CEC F-06-A-96 Fatty Acid Methyl prohibited Ester

EXAMPLE 3

[0449] The performance of fuel compositions of example 2 in modern diesel engines having a high pressure fuel system may be tested according to the CECF-98-08 DW 10 method. This is referred to herein as the DW10B test.

[0450] The engine of the injector fouling test is the PSA DW10BTED4. In summary, the engine characteristics are:

[0451] Design: Four cylinders in line, overhead camshaft, turbocharged with EGR

[0452] Capacity: 1998 cm.sup.3

[0453] Combustion chamber: Four valves, bowl in piston, wall guided direct injection

[0454] Power: 100 kW at 4000 rpm

[0455] Torque: 320 Nm at 2000 rpm

[0456] Injection system: Common rail with piezo electronically controlled 6-hole injectors.

[0457] Max. pressure: 1600 bar (1.610.sup.8 Pa). Proprietary design by SIEMENS VDO

[0458] Emissions control: Conforms with Euro IV limit values when combined with exhaust gas post-treatment system (DPF)

[0459] This engine was chosen as a design representative of the modern European high-speed direct injection diesel engine capable of conforming to present and future European emissions requirements. The common rail injection system uses a highly efficient nozzle design with rounded inlet edges and conical spray holes for optimal hydraulic flow. This type of nozzle, when combined with high fuel pressure has allowed advances to be achieved in combustion efficiency, reduced noise and reduced fuel consumption, but are sensitive to influences that can disturb the fuel flow, such as deposit formation in the spray holes. The presence of these deposits causes a significant loss of engine power and increased raw emissions.

[0460] The test is run with a future injector design representative of anticipated Euro V injector technology.

[0461] It is considered necessary to establish a reliable baseline of injector condition before beginning fouling tests, so a sixteen hour running-in schedule for the test injectors is specified, using non-fouling reference fuel.

[0462] Full details of the CEC F-98-08 test method can be obtained from the CEC. The coking cycle is summarised below.

[0463] 1. A warm up cycle (12 minutes) according to the following regime:

TABLE-US-00004 Duration Engine Speed Step (minutes) (rpm) Torque (Nm) 1 2 idle <5 2 3 2000 50 3 4 3500 75 4 3 4000 100

[0464] 2. 8 hrs of engine operation consisting of 8 repeats of the following cycle

TABLE-US-00005 Duration Engine Speed Load Torque Boost Air After Step (minutes) (rpm) (%) (Nm) IC ( C.) 1 2 1750 (20) 62 45 2 7 3000 (60) 173 50 3 2 1750 (20) 62 45 4 7 3500 (80) 212 50 5 2 1750 (20) 62 45 6 10 4000 100 * 50 7 2 1250 (10) 20 43 8 7 3000 100 * 50 9 2 1250 (10) 20 43 10 10 2000 100 * 50 11 2 1250 (10) 20 43 12 7 4000 100 * 50 * for expected range see CEC method CEC-F-98-08

[0465] 3. Cool down to idle in 60 seconds and idle for 10 seconds 4. 4 hrs soak period

[0466] The standard CEC F-98-08 test method consists of 32 hours engine operation corresponding to 4 repeats of steps 1-3 above, and 3 repeats of step 4. ie 56 hours total test time excluding warm ups and cool downs.

EXAMPLE 4

[0467] The ability of additives of the invention to remove Internal Diesel Injector Deposits' (IDIDs) may be measured according to he test method CEC F-110-16, available from the Co-ordinating European Council. The test uses the PSA DW10C engine.

[0468] The engine characteristics as follows:

TABLE-US-00006 Design: Four cylinders in line, overhead camshaft, variable geometry turbocharger with EGR Capacity: 1997 cm.sup.3 Combustion chamber: Four valves, bowl in piston, direct injection Power: 120 kW @ 3750 rpm Torque: 340 Nm @ 2000 rpm Injection system: Common rail with solenoid type injectors Delphi Injection System Emissions control: Conforms to Euro V limit values when combined with exhaust gas post-treatment system

[0469] The test fuel (RF06) is dosed with 0.5 mg/kg Na in the form of Sodium Naphthenate+10 mg/kg Dodecyl Succinic Acid (DDSA).

[0470] The test procedure consists of main run cycles followed by soak periods, before cold starts are carried out.

[0471] The main running cycle consist of two speed and load set points, repeated for 6 hrs, as seen below.

TABLE-US-00007 Step Speed (rpm) Torque (N .Math. m) Duration (s) 1 3750 280 1470 1 - Ramp .fwdarw.2 30 2 1000 10 270 2 - Ramp .fwdarw.1 30

[0472] Cycle Profileiso Power110 kW

[0473] 4000

[0474] 3500

[0475] 3000

[0476] 2500

[0477] 2000

[0478] 1500

[0479] 1000

[0480] 500

[0481] 0 10.0 20.0 30.0 40.0 50.0 60.0 70.0

[0482] Time iminj

[0483] Each Cycle is represented 6 times so the complete main run phase lasts 6 hours

[0484] During the main run, parameters including, Throttle pedal position, ECU fault codes, Injector balance coefficient and Engine stalls are observed and recorded.

[0485] The engine is then left to soak at ambient temperature for 8 hrs.

[0486] After the soak period the engine is re-started. The starter is operated for 5 seconds; if the engine fails to start the engine is left for 60 seconds before a further attempt. A maximum of 5 attempts are allowed.

[0487] If the engine starts the engine is allowed to idle for 5 minutes. Individual exhaust temperatures are monitored and the maximum Temperature Delta is recorded. An increased variation in Cylinder-to-Cylinder exhaust temperatures is a good indication that injectors are suffering from IDID. Causing them to either open slowly or stay open to long.

[0488] An example below of all exhaust temperatures with <30 C. deviation, indicating no sticking caused by IDID.

[0489] The complete test comprises of 6 Cold Starts, although the Zero hour Cold Start does not form part of the Merit Rating and 56 hr Main run cycles, giving a total of 30 hrs engine running time.

[0490] The recorded data is inputted into the Merit Rating Chart. This allows a Rating to be produced for the test. Maximum rating of 10 shows no issues with the running or operability of the engine for the duration of the test.

[0491] An example below:

EXAMPLE 5

[0492] The effectiveness of the additives of the invention in older traditional diesel engine types was assessed using a standard industry testCEC test method No. CEC F-23-A-01.

[0493] This test measures injector nozzle coking using a Peugeot XUD9 A/L Engine and provides a means of discriminating between fuels of different injector nozzle coking propensity. Nozzle coking is the result of carbon deposits forming between the injector needle and the needle seat. Deposition of the carbon deposit is due to exposure of the injector needle and seat to combustion gases, potentially causing undesirable variations in engine performance.

[0494] The Peugeot XUD9 A/L engine is a 4 cylinder indirect injection Diesel engine of 1.9 litre swept volume, obtained from Peugeot Citroen Motors specifically for the CEC PF023 method.

[0495] The test engine is fitted with cleaned injectors utilising unflatted injector needles. The airflow at various needle lift positions have been measured on a flow rig prior to test. The engine is operated for a period of 10 hours under cyclic conditions.

TABLE-US-00008 Stage Time (secs) Speed (rpm) Torque (Nm) 1 30 1200 30 10 2 2 60 3000 30 50 2 3 60 1300 30 35 2 4 120 1850 30 50 2

[0496] The propensity of the fuel to promote deposit formation on the fuel injectors is determined by measuring the injector nozzle airflow again at the end of test, and comparing these values to those before test. The results are expressed in terms of percentage airflow reduction at various needle lift positions for all nozzles. The average value of the airflow reduction at 0.1 mm needle lift of all four nozzles is deemed the level of injector coking for a given fuel.

EXAMPLE 6

[0497] A diesel fuel composition comprising additive A15 (105 ppm active) was tested according to the XUD9 test described in example 5 and its performance compared with that of base fuel. The results are shown in table 4:

TABLE-US-00009 % Flow loss Nozzle Nozzle Nozzle Base Fuel Additive 1 2 3 Nozzle 4 Average RF-06-03 n/a 68 81 79 64 73 RF-06-03 A15 @ 3 3 43 3 13 105 mg/kg