GB2375800A

GB2375800A - An aerosol dispenser containing a de-coking formulation

Info

Publication number: GB2375800A
Application number: GB0112588A
Authority: GB
Inventors: Gerard Shields
Original assignee: Tetrosyl Ltd
Current assignee: Tetrosyl Ltd
Priority date: 2001-05-24
Filing date: 2001-05-24
Publication date: 2002-11-27
Anticipated expiration: 2021-05-24
Also published as: GB2375800B; GB0112588D0

Abstract

An aerosol dispenser containing and being for the discharge of a de-coking, or de-carbonizing formulation, wherein the de-coking formulation is an aqueous solution of an alkylene diol containing at least one surfactant and the dispenser incorporates a pressurised dispensing fluid separated from the de-coking formulation by a diaphragm and being adapted to dispense the de-coking formulation when the aerosol is discharged/activated. The de-coking formulation may be disposed within a bag within the aerosol cannister and the pressurised fluid is disposed between the bag and the cannister. The alkylene diol may be 1, 2 propanediol. The surfactant may be a single surfactant or an admixture of one or more surfactant selected from a group comprising an ester of an aryl sulphonate, a tertiary amine ethoxylate and a tertiary amine containing at least one C<SB>8-18</SB> alkyl group. The de-coking formulation may contain a synthetic lubricant which is an admixture of polyethylene/polypropylene glycol butyl ether.

Description

AEROSOL DISPENSER The present invention relates to an aerosol dispenser containing a de-coking formulation intended particularly but not exclusively for use in de-coking internal combustion engines such as those found in automobiles.

During the operation of internal combustion engines coke deposits can build I up. The deposits are formed as a product from the incomplete combustion of the fuel used. Engine oil may also be thermally degraded into coke.

Even perfectly maintained engines will build up some coke deposits.

However, the deposition of coke may be accelerated as a result of poor car maintenance, particularly from a lack of attention to the fuel/air ratio entering the cylinders: an over-rich fuel mixture, i. e. one that contains more fuel that can be completely oxidised by the charge of air in the cylinder, will produce a large amount of coke deposits.

Another factor reputed to be involved in coke deposition is driving style. A car driven mostly in an urban environment is exposed to a combination of low engine speeds, high engine temperatures, poor air quality and slow traffic speeds, all of which are recognised to accelerate coke build up.

Coke deposits cause a loss of performance as a result of less power reaching the flywheel of the engine. This may be caused directly whereby, for example, the coke deposits affect the"breathing"of the engine. The amount of fuel in the fuel/air mixture reaching the cylinders of the engine becomes insufficient or in the alternative excessive, thus the mixture bums less efficiently and so less power is developed. Furthermore during engine operation coke deposits are heated to an elevated temperature such that they begin to glow red hot. The thus heated deposits cause premature ignition of the fuel/air mixture directed to the cylinders. Premature ignition gives rise to poor engine running and increased engine wear.

One way to remove. the coke from a car engine is completely to dismantle the engine, clean and replace any parts that have coke deposits and subsequently re-build the engine. Obviously this is a highly time consuming and consequently expensive process.

A much cheaper way to reduce coke deposits is to apply a de-coking composition. These are commonly available as an aerosol type spray, whereby the engine is run at a certain engine speed and the aerosol is sprayed into the engine manifold. The de-coking formulation is then carried into the engine where it attacks and displaces a portion of the coke deposited.

A major problem which has been observed when using these aerosols is the

effect that the aerosol propellant has upon the running of the engine. Common aerosol zzl propellants, such as butane, although flammable are not suitable for spraying into hot, ZD running automobile engines.

Compressed air has been used as a propellant in an attempt to overcome this problem. Normally the compressed air is provided above the formulation in the aerosol and also in a pressurised capsule which is disposed within the de-coking formulation and which has a release valve. On activation of the aerosol the formulation is discharged by the pressure of compressed air above the formulation.

Additional compressed air is then released from the capsule to replace the volume discharged. Obviously compressed air is discharged with the de-coking formulation.

We have now observed that the injection of air with the de-coking formulation can adversely affect the engine as the fuel air mixture is detrimentally influenced, as a result of increasing the proportion of air above the desired amount in the air/fuel ratio.

It is an object of the present invention to provide a de-coking formulation dispenser that overcomes/obviates the problems outlined above.

According to the present invention there is provided an aerosol dispenser containing and being for the discharge of a de-coking formulation wherein the decoking formulation is an aqueous solution of an alkylene diol containing at least one surfactant and the dispenser incorporates a pressurised dispensing fluid separated from the de-coking formulation by a diaphragm and being adapted to dispense the decoking formulation when the aerosol is discharged/activated.

In the aerosol of the present invention the de-coking formulation is thus dispensed by a driving force provided by the pressurised fluid which is, for preference, compressed air. The compressed air (or other dispensing fluid) is itself not discharged during operation of the aerosol thus preventing the adverse effects (of air or other dispensing fluid) upon an engine.

The aerosol dispenser of the invention may be of the"bag in can"type in which the de-coking formulation is contained within a flexible bag, the interior of which communicates with the dispensing nozzle of the aerosol. The pressurised dispensing fluid (e. g. compressed air) is provided within the volume defined by the outer surface of the bag and the inner surface of the aerosol canister. Thus on activation of the aerosol de-coking formulation is discharged by the action of the

dispensing fluid on the outside of the bag (with no propellant discharge).

I Generally the de-coking formulation is discharged into the engine when the latter is running. A preferred running speed is commonly referred to as a"fast idle", which is recognised to mean that the engine is operating at around 2500 rpm. Generally the composition is discharged into the inlet manifold of the engine.

The alkylene diol is preferably present in the de-coking formulation present in an amount of 10-30% by weight of the formulation, more preferably 15-25%, even more preferably 18-22% and most preferably about 20%.

For preference, the alkylene diol is a 2-6 alkylene diol. The alkylene diol may be a single compound (preferably C3) or may comprise a mixture of alkylene diols of different chain lengths, preferably with C3 predominating. For preference the alkylene groups are straight chain. The diol is preferably a glycol. Most preferably the alkylene diol is 1,2-propanediol.

Preferably the surfactant is present in the de-coking formulation in an amount of between 0.01-2. 0% by weight, more preferably 0.01-1. 0%, even more preferably 0. 01-0. 5% and most preferably about 0.2%.

The surfactant is preferably a single surfactant or an admixture of one or more surfactants selected from the group comprising an ester of an aryl sulphonate, a tertiary amine ethoxylate and a tertiary amine containing at least one CS-1s alkyl group Preferably the tertiary amine containing at least one C8-18 alkyl group is present

in an amount of 0. 002-0. 008% by weight of the de-coking formulation, more I preferably 0. 003-0. 007% and most preferably about 0.005%.

It is preferred that the at least one alkyl group has 10 to 16 carbon atoms, and

most preferably 12 to 14 carbon atoms (e. g. mixed C12 - C14).

A suitable tertiary amine containing at least one C8-18 alkyl group is available under the name Primene 81-R (available from Rohm & Haas).

It is preferred that the de-coking composition further comprises a synthetic lubricant.

The synthetic lubricant is preferably present in an amount of 1-4%, by weight of the formulation, more preferably 2-4% and most preferably about 2.6%.

Preferably the synthetic lubricant is a polyalkylene (2-6) diol ether. The polyalkylene diol ether may be formed of a single monomer (e. g. a simple polymer comprised of one monomeric unit, such as butene-4, polymerised to polybutene) or may comprise a mixture of monomers of different chain lengths (e. g. a co-polymer

comprising a combination of, for example, propylene-C3, and ethene-2). The polyalkylene (2-6) diol ether may comprise an admixture of individual simple and/or block co-polymers. For preference, the alkylene group of the polyalkylene (2-6) diol ether has 2-3 carbon atoms. Most preferably the polyalkylene is an admixture of polyethylene and polypropylene. The diol is preferably present as a glycol. Preferably the ether function is a C2-6 alkyl group with butyl (C4) being most preferred.

A polyalkylene (2-6) diol ether which may be used is available under the name Breox 50A50 (available from Laporte Performance Chemicals Ltd).

The de-coking formulation preferably contains an admixture of dimethyl-and diethyl phenols. Preferably said admixture is present in an amount of 0. 001-0. 04% by weight, more preferably 0. 005-0. 035% and most preferably about 0.020%.

Preferably the admixture comprises a 2,4 and a 2,5 isomer of each of the respective dialkyl phenols. Generally the admixture contains about 15% by weight of an admixture of 2,4/2, 5 dimethyl phenol and about 85% by weight of an admixture of 2,4/2, 5 diethyl phenol.

A preferred de-coking formulation in accordance with the invention comprises the following :-

Component Wt% Function 1, 2-propanediol 20 Carbon removal polyethylene/polypropylene glycol butyl 2. 6 Synthetic lubricant ether admixture phosphuric acid ester of aryl sulphonate/ 0.1 Emulsifier/wetting agent. sodium salt thereof admixture tertiary amine ethoxylate based upon 0. 1 Emulsifier/wetting agent. primary coco-amine C12-14 tertiary alkyl amine admixture 0.005 Emulsifier/wetting agent.

2, 4/2, 5-dimethyl- (15wt%) and 0.02 Carbon removal 2,4/2, 5-diethyl- (85wt%) phenol admixture. water balance Carbon removal

Claims

CLAIMS 1. An aerosol dispenser containing and being for the discharge of a de-coking formulation wherein the de-coking formulation is an aqueous solution of an alkylene diol containing at least one surfactant and the dispenser incorporates a pressurised

dispensing fluid separated from the de-coking formulation by a diaphragm and being ZD z : adapted to dispense the de-coking formulation when the aerosol is discharged/activated.
2. A dispenser according to claim 1, wherein the pressurised fluid is compressed air.
3. A dispenser according to claim 1 or 2, wherein the dispenser comprises a bag in can aerosol canister.
4. A dispenser according to claim 3, wherein de-coking formulation is disposed within the bag of the aerosol canister and the pressurised fluid is disposed within a volume defined by the outer surface of the bag and the inner surface of the aerosol canister.
5. A dispenser according to any one of claims 1 to 4, wherein the alkylene diol is present in an amount of 15-25% by weight of the de-coking formulation, more preferably 18-22% and most preferably about 20%.
6. A dispenser as claimed in claim 5, wherein the alkylene diol is 1,2propandiol
7. A dispenser according to any one of claims 1 to 6, wherein the surfactant is present in the de-coking formulation in an amount of between 0.01-2. 0% by weight, more preferably 0.01-1. 0%, even more preferably 0.01-0. 5% and most preferably about 0.2%.

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8. A dispenser according to claim 7, wherein the surfactant is a single surfactant or an admixture of one or more surfactants selected from the group comprising an ester of an aryl sulphonate, a tertiary amine ethoxylate and a tertiary amine containing at least one C8-18 alkyl group
9. A dispenser according to claim 8, wherein the tertiary amine containing at least one C8-18 alkyl group is present in an amount of 0. 002-0. 008% by weight of the de-coking formulation, more preferably 0. 003-0. 007% and most preferably about 0.005%.
10. A dispenser according to claim 9, wherein the alkyl group of the tertiary amine is a C12-14 alkyl group.
11. A dispenser according to any one of claims 1 to 10, wherein the de-coking formulation comprises a synthetic lubricant.
12. A dispenser according to claim 11, wherein synthetic lubricant is present in an amount of 1-4%, by weight of the formulation, more preferably 2-4% and most preferably about 2.6%.
13. A dispenser according to claim 12, wherein the synthetic lubricant is an admixture of polyethylene/polypropylene glycol butyl ether.
14. A dispenser according to any one of claims 1 to 13, wherein the de-coking formulation comprises an admixture of dimethyl-and diethyl phenols present in an amount of 0. 001-0. 04% by weight, more preferably 0. 005-0. 035% and most preferably about 0.020%.

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15. A dispenser according to claim 1 to 14, wherein the de-coking formulation comprises an admixture of 15% by weight of an admixture of 2,4/2, 5 dimethyl phenol and about 85% by weight of an admixture of 2,4/2, 5 diethyl phenol.