GB2353803A

GB2353803A - Gasoline compositions

Info

Publication number: GB2353803A
Application number: GB9920672A
Authority: GB
Inventors: Peter Michael Radley; Andrea Sneddon
Original assignee: Associated Octel Co Ltd
Current assignee: Innospec Ltd
Priority date: 1999-09-01
Filing date: 1999-09-01
Publication date: 2001-03-07
Also published as: GB9920672D0

Abstract

Gasoline compositions comprising a gasoline and a polyisobutene amine, wherein the polyisobutene amine has no more than one basic nitrogen atom in the amine moiety, additive compositions comprising a polyisobutene amine and methods of conferring detergency on a gasoline fuel.

Description

2353803 70325.600 GASOLINE COMPOSITIONS The present invention relates to

detergents for use in gasoline fuels.

Gasolines generally contain numerous deposit-forming substances. These substances tend to form deposits on the intake valves and other engine surfaces due to oxidation and polymerisation of the gasoline. These deposits, even,when present in relatively minor amounts, restrict entry of the fuel mixture into the combustion chamber. This in turn leads to loss of power, stalling and poor acceleration. Therefore the development of effective fuel detergents or deposit control additives to prevent or control such deposits is of considerable importance and numerous such materials are known in the art.

Detergents based on polyisobutene (PIB) amines are well known intake valve deposit control detergents for use in gasoline fuelled engines. They are readily prepared in leading commercial processes by chlorinating the PIB and then aminating the resultant PIB chloride. This class of gasoline detergents is disclosed in many patents describing the preparation and use of exemplary PIBs including US 3,574,576, US 4,022,589 and US 3,960, 515.

We have discovered, and this constitutes our invention, that PIB detergents having only one basic nitrogen are especially good gasoline detergents and more effective than those described in the prior art. Although amines containing only one nitrogen are mentioned as possible amines in the prior art, PIBamines containing one basic nitrogen have not before been specifically disclosed as being significantly better than PIBamines with more than one nitrogen.

One aspect of the invention thus provides a gasoline composition comprising a gasoline and a polyisobutene amine, wherein the polyisobutene amine has no more than one basic nitrogen atom in the amine moiety. 5 Preferably the polyisobutene moiety has a molecular weight of 300-3000, for example about 560, in particular 700-1500, for example about 780 or about 1000.

Conventional PIBs and so-called 11 high- reactivity" PIBs (see for example EP-B-0 565 285) are suitable for use in the invention. High reactivity in this context is defined as a PIB wherein at least 500-., preferably 70-. or more, of the terminal olefinic double bonds are of the vinylidene type.

Amines which may be employed in forming the PIBamines include any that have the ability to react with a functionalised PIB.

Preferred amines are n-butylamine, n-propylamine and ammonia.

The PIBamines of the invention are blended into gasolines in amounts sufficient to provide from 10 to 2000 ppm (weight basis) of active detergent in the fuel. Preferred amounts range from 30 to 800 ppm, most usually from 50 to 500 ppm and preferably from 100 to 200 ppm.

They are conveniently, although not necessarily, formulated as additive compositions comprising a PIBamine according to the invention and a fuel miscible solvent, and such additive compositions form a further aspect of the invention. Solvents include aromatic or aliphatic hydrocarbons, preferably boiling in the range 180-2700C. The amount of solvent incorporated in an additive composition will depend on the desired final 3 composition by weight.

The invention further provides a method of conferring detergency on a gasoline fuel comprising the addition to said fuel of a polyisobutene amine as defined above, and a method of inhibiting deposit formation in a spark ignition engine, for example intake valve deposit formation, comprising operating said engine on a gasoline composition as defined above.

Polyisobutene amines as defined above are either available comm ercially or can be manufactured by conventional means, for example chlorinating the PIB and then aminating the resultant PIE chloride. Alternative synthetic routes might include reaction of a PIE with CO/H2 followed by amination.

The term "gasoline" as used herein means a hydrocarbon fuel boiling in the gasoline range, i.e. 30-2300C. Such gasolines may comprise mixtures of saturated, olefinic and aromatic hydrocarbons. These hydrocarbons may in part be replaced in the fuel by alcohols, ethers, etc., in an amount up to 201; by weight.

The invention also contemplates gasoline compositions, and additive compositions therefor, comprising combinations, preferably synergistic combinations, of a polyisobutene amine as defined above and one or more of: fuel soluble carrier fluids, dehazers added to minimise water absorption, corrosion inhibitors and antioxidants. Suitable carrier fluids include alkoxylated phenols and alkoxylated alcohols or polyols.

The invention will be better understood and illustrated from the following Examples which should not be regarded as limiting the invention in any way.

4 Example 1

297 g of PIB-Cl derived from 1000 mol. wt. PIB (chlorine content 4.89% m/m) was placed into a high pressure autoclave with 290 ml hexane and 352 g of ammonia gas.

The autoclave was sealed and heated to 1200C for 20 hours. Following this the reactor was cooled and vented and the crude product, containing solid salts, was unloaded. The solid was filtered off and the solution washed with water and dried over sodium sulphate. On removal of the solvent 229 g of product remained.

Analysis: solvent 05-,'.- M/M nitrogen 1.10-. M/M is chlorine 1.01% M/M Example 2

153 g of PIB-Cl derived from 1000 mol. wt. PIB (chlorine content 4.89$ m/m) was placed in a stirred reactor with 61.6 g n-butylamine and 50 ml Shellsol solvent. The reactor contents were heated to reflux for 19.5 hours.

Crystalline solid could be seen in the solution as the reaction proceeded. The reaction was allowed to cool and an excess of aqueous sodium carbonate was mixed with the reactor contents. After separation the organics were washed with water and dried over sodium sulphate.

The unreacted butylamine was removed under reduced pressure leaving 190 g product plus solvent.

Analysis: solvent 23-. m/m nitrogen 0.95% M/M chlorine 1% m/m Exam-ole 3 encTine tests In order to show detergency effectiveness of the detergent compositions of the invention, engine tests were performed according to a standard engine test on a Mercedes M102E engine.

Measurements were made of the inlet valve deposit weights. 10 Example. Concentration (ppm) Deposits (mg) Base fuel ----- 231 Succinimide 150 108 detergent - TEPA (5 nitrogens) PIBamine 150 65 detergent - EDA (2 nitrogens) Example 1 150 7 (1 nitrogen) Example 2 150 10 (1 nitrogen) The results clearly demonstrate that the additive of the invention is significantly more effective than additives containing more than one basic nitrogen.

Claims

1. A gasoline composition comprising a gasoline and a polyisobutene, amine, wherein the polyisobutene amine has no more than one basic nitrogen atom in the amine moiety.

2. A composition according to claim 1 wherein the polyisobutene moiety has a molecular weight of 300-3000.

3. A composition according to claim 2 wherein the polyisobutene moiety has a molecular weight of 700-1500.

4. A composition according to claim 1 comprising from 10 to 2000 ppm (weight basis) of polyisobutene amine.

S. A composition according to claim 7 comprising from 30 to 800 ppm of polyisobutene amine.

6. A composition according to claim 8 comprising from so to 500 ppm of polyisobutene amine.

7. An additive composition comprising a polyisobutene amine as defined in any preceding claim and a fuel miscible solvent.

8. A method of conferring detergency on a gasoline fuel comprising the addition to said fuel of a polyisobutene amine as defined in any of claims 1 to 6.

9. A method of inhibiting deposit formation in a spark ignition engine comprising operating said engine on a gasoline composition according to any of claims 1 to 6.