JPS6357690A - Abrasion resistant additive in alkanol fuel - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

BACKGROUND OF THE INVENTION Field of the Invention This invention relates to the use of selected additives in alkanol fuels to reduce or suppress wear.

The use of alcohol, particularly methanol, as engine fuel has been known for some time.

However, the use of methanol and other such alkanol fuels, especially when used neat,
It was found that excessive [+5] was generated.

It has been found that much of the wear caused by this type of fuel, such as methanol, occurs in the bisF ring and upper cylinder areas of the engine.

This wear results from "washing out" the lubricant film and electrochemically attacking the metal surfaces of the cylinder liner by the fuel and its corrosive combustion products. Fuel blow-through to lubricant (
blovby ), ie, the blowing of the fuel and its combustion products through the ring, and the resulting reaction with the lubricating additives, can also lead to a general increase in engine wear with alkanol fuels.

Changing the lubricant formulation was one way to solve the wear problems associated with alkanol fuels mentioned above. Other attempts have included the use of additives in methanol fuel to aid in lubricity while reducing wear characteristics. Additives used: fatty alcohols, alcohol ethoxylates, fatty acids and ethoxylates,
esters, including polyols and phosphate esters;
It contained a polyalkylene glycol as disclosed in US Pat. No. 4,575,560. Other additives are U.S. Pat. No. 4177.768, U.S. Pat.
Further additives specifically noted as useful in alkanol fuels include those containing multiple organo acids as shown in U.S. Pat. No. 4,242.099 and U.S. Pat. Turtle disclosed in No. 951-
Hidota oxyhydrocycarbonamide, U.S. Patent 4204
No. 481, fatty acid amides or esters of jetanolamine, and linear aliphatic primary amines as disclosed in US Pat. No. 4,201L190.

As mentioned above, although a number of emerging approaches have been disclosed to provide reduced wear in alkanol-fueled engines, there is a need for further fuel systems that provide reduced engine wear and increased lubricity while retaining compatibility. There is.

SUMMARY OF THE INVENTION Alkanol fuels containing a selected additive that is an ester having at least two free hydroxyl groups of a carboxylic acid and a polyhydric alcohol have now been provided with improved wear and lubrication properties. More specifically, the present invention relates to an additive which is an ester of a monohydric alkanol having 1 to 5 carbon atoms, a monocarboxylic acid or a polycarboxylic acid, and a polyhydric alcohol. the acid has up to about 4 carboxylic acid groups and about 12 to 90 carbon atoms, and the alcohol has up to about 2 to 10 hydroxyl groups and about 2 to 30 carbon atoms. and the ester is directed toward a fuel composition having at least two free hydroxyl groups.

The composition has improved lubricity and provides improved wear reduction.

DETAILED DESCRIPTION OF THE INVENTION The present invention provides at least two carboxylic acids and a polyhydric alcohol.
The present invention is directed to alkanol fuel compositions with improved wear and lubrication properties containing selected additives that are esters having tetraxyl groups.

The ester additive selected for use in the present invention is typically derived from the esterification of a monocarboxylic or polycarboxylic acid with a polyhydric alcohol, the process being at least two
of free hydroxyl groups. -Layer Specifically, the ester additive used in the present invention is a hydroxy-containing ester of a monocarboxylic or polycarboxylic acid and a polyhydric alcohol, the chain acids having up to about 4 carboxylic acid groups and about 8 to
Alfur has about 2 to 10 syl groups and about 2 to 30 carbon atoms.

The acids used to prepare the esters are aliphatic acids having up to about 4 carboxylic acid groups and from about 8 to about 90 carbon atoms.
Saturated or unsaturated, linear or branched mono- or polycarboxylic acids. When the chain acid is a monocarboxylic acid, it usually contains about 8 to about 30, preferably about 10 to about 28, more preferably about 12 to about 22 carbon atoms.

When the acid used to make the ester additive of the present invention is a polycarboxylic acid, the fatty acid usually has about 2 to about 4, preferably about 2 to about 5, preferably about 2 -layers of carboxylic acid groups. saturated or unsaturated, preferably saturated, polycarboxylic acids. The acid contains from about 12 to about 90, preferably from about 24 to about 90, more preferably from about 24 to about 65 carbon atoms, with at least about 9 to about 42, preferably about 12, between carboxylic acid groups. Contains up to about 42 carbon atoms, more preferably about 16 to about 22 carbon atoms.

The alcohol used to prepare the ester additives of the present invention typically has about 2 to about 10, preferably about 2 to about 6,000 alcohols in the molecule.
, more preferably about 2 to about 4 hydroxyl groups and about 2
~90, preferably about 2-30, more preferably about 2
Aliphatic, saturated or unsaturated, straight chain or branched polyhydric alcohols having from about 12 carbon atoms, most preferably from about 2 to about 5 carbon atoms.

For further explanation and illustrations of the acids and alcohols mentioned above, see Kirkoosmer, Encyclopedia Opchemical Technology, 2nd edition, vol. 1, 1965;
See pages 224-254 and 531-598.

Whatever combination of acid and alcohol is used to prepare the ester additives of the present invention, the final compound must have at least two free hydroxyl groups;
And it is preferable that the terminal group is hydroxyl.

When producing the ester additive used in the present invention,
The ratio of alcohol to acid can usually be varied, but is chosen to minimize the amount of free acid remaining in the final product.

In many cases, a small surplus of acid to alcohol is used, but the amounts will depend on the particular acid and alcohol used to make the ester additive.

Preferred ester additives for use in the present invention are those derived from the esterification of polycarboxylic acids with glycols or glyceryls, preferably glycols. mosquito,
When using glycols, such esters can typically be polyesters or polyesters having the following general formula: (1) [0-R-00C-R■-COOR' -0
H(2) HO-R-00C-R''-COOR-00
C-R"-COOR'-01'I, where R" is a hydrocarbon radical of the acid and each R and R' is the same in the context of a glycol or diol as defined herein. - or different hydrocarbon radicals).

It will be appreciated that esters of the type represented by the above formula may be obtained by esterifying a polycarboxylic acid or a mixture of chain acids with a diol or a mixture of said diols.

The oil-insoluble glycol reacted with the polycarboxylic acid can be a linear or branched alkanediol, ie, an alkylene glycol, or an oxa-alkanediol, ie, a polyalkylene glycol. Alkanediols can have about 2 to about 12 carbon atoms in the molecule, preferably about 2 to about 5 carbon atoms, and oxa-alkanediols usually have about 4 to about 200, preferably about 4 to about It has 100 carbon atoms. Oxa-
Alkanediols (polyalkylene glycols) naturally contain periodically repeating groups of the following formula: (wherein R is H
SCM can be C,H, or C,H, where X is from 2 to 1001, preferably from 2 to 25).

A preferred alkanediol or alkylene glycol is ethylene glycol, and a preferred oxa-alkanediol or polyalkylene glycol is diethylene glycol. As previously mentioned, glycerol may also be used in preparing esters of polycarboxylic acids, and the component is also intended to include higher molecular weight analogs thereof.

Esters can also be made by reacting alcohols, preferably polyhydric alcohols, with esters and/or polyesters in which some free acid may be present.

A suitable ester for the reaction is lanolin and a preferred alcohol is sorbitol. The alcohol reacts with the acid present in the ester and/or undergoes transesterification to form the desired ester compound with free hydroxyl groups.

Any of the above-mentioned esters can be effectively used, however, the carboxyl groups of the polycarzanoic acid are separated from each other by about 16 to about 22 carbon atoms and the hydroxyl groups are separated by a carbon atom from the nearest carboxyl group. Approximately 2~
Best results are obtained with compounds that are separated by about 12. Particularly impressive results were obtained with additives made by esterifying dimers of fatty acids, especially those with conjugated unsaturation, with melihydroxy compounds. Although the patentability of the present invention is not predicted based on the mechanism by which the dimers useful in the present invention are produced, the dimer acids are produced from linoleic acid, oleic acid, and mixtures of these acids. A series of proposed reactions are shown below: Commercial processes for the production of these fatty acid dimers usually lead to the formation of globules and the products thus obtained contain small amounts of unreacted monomers. There are some cases where you can. the result,
Commercially available dimer acids may contain any dimer, and it is within the scope of this invention to use such mixtures.

Particularly preferred hydroxy-substituted ester additives useful in the present invention include fatty acid dimers and glycols such as those exemplified.
The result is a reaction product, preferably with an oil-insoluble glycol, which can be made by a variety of techniques.

Preferred acid dimers are linoleic acid, oleic acid, or a mixed dimer of linoleic acid and oleic acid, and may contain some monomers and dimers. In addition to ethylene glycol and polyethylene glycol, other particularly satisfactory glycols are, for example, propylene glycol, polypropylene glycol, butylene glycol, polybutylene glycol, and the like.

It should be understood that when the ester additive of the present invention is obtained from a monocarboxylic alcohol, the polyhydric alcohol contains at least 3 hydroxyl groups to provide the necessary human 0x functionality to the final product. When making esters of fatty monocarboxylic acids, the preferred alcohol is
It is le. Preferably, the ester formed is ethoxylated.

A preferred fatty acid is coconut acid (coconut ae
ld).

The fuel composition of the present invention primarily comprises an alkanol, i.e. the alkanol is at least 50% by weight of the composition, preferably a major portion, more preferably at least 80% by weight.
Configure. Useful alkanols are monohydroxy alcohols containing from 1 to S carbon atoms, with saturated ioaliphatic-hydric alcohols being preferred. Examples of alcohols of this type are methanol, ethanol, propatool, n-butanol 1 isobutanol, amyl alcohol, isoamyl alcohol/l'col, with methanol being preferred.

The dosoxyl-containing ester additives of the present invention typically have an effective wear-reducing amount, particularly from about α0003 to about 2.0% by weight, based on the total weight of the fuel composition, preferably about α001 ~ about tO weight -1, preferably about 0.0
It is used at a concentration of 0.02 to about CL5 weight de.

Other additives known in the art and that do not adversely affect the selected additives of the present invention can be used in the fuel composition. Such additives can include demulsifiers, dyes, antioxidants, corrosion inhibitors, ignition promoters, and the like.

The following examples further illustrate the invention and are not intended to be considered limiting.

Example 1 A fuel composition is made and the composition is produced by esterifying methanol and a Rinow/I/F dimer acid with diethylene glycol and has the following formula: (wherein nm 1-5) It contained 58 ppm of ester.

Tests were conducted to determine the effect of use of the present fuel composition on wear using a slant 6 dodge engine operating under conditions that promote wear.

The engine ran at 700 rpfm % no load for 10 minutes then 2000 rpfm and load 105 lb,
ft, for 20 minutes. This cycle was repeated for 72 hours and the oil sump temperature was maintained at 50°C. Samples of the used oil were removed at 24 hour intervals and analyzed for wear metals by plasma emission spectroscopy.

The amount of worn metal in the oil used after 72 hours is F・72.7p
pm and Cm I 18 ppm. When the same methanol fuel is heated with ester additive, F @ 105 Sprm and Css 26.8 ppm
(average of two experiments).

Example 2 A fuel composition was made containing methanol and 58 ppm of polyoxyethylene Sorbi F-luranorin.

This composition was tested as in Example 1 to obtain F.39.6PP1.
! 1 and Cm2α9 ppm of metal wear.

Example 3 Another series of tests was carried out on a cyclically operated tilt-six dorsal engine as in Example 2. A specially formulated oil labeled Oilman was used in some of these tests. A conventional commercial lubricant designated Oil B containing an ester formed by esterifying the dimer acid of linoleic acid and diethylene glycol was used in other tests.

A third oil, designated Oil C, similar to Oil B but without the ester additive was also tested. The results are presented in Table I below. As mentioned above, the F concentration before use is a measure of engine wear.

table ! Oil person Unleaded premium gasoline 34 Oil B Methanol 50 year old Oil person Methanol 52 Oil A Methanol + 90 ppm ester m 3
゜Oil B Methanol 105
Oil C Methanol Table 84 shows that the combination of specially formulated lubricant and methanol with ester additive produced significantly less engine wear than the same lubricant combination with methanol without ester additive. Recognize. Also, the combination of specially formulated oil and methanol with ester additive produced significantly less wear than the commercial pre-merchandising both with and without the ester additive when no ester was added to the methanol.

The table below shows the results of a slope 6 dot engine using a specially formulated oil (Oil A) and methanol with an ester additive.
A comparison of the wear at 2 hours and the wear produced using premium unleaded gasoline and the commercial lubricant (Oil B) described above is presented. Test conditions were similar to those described in Example 1.

Table ■ Oil A Methanol + 90 ppm Nisterlo) 2
8 Oil B Gasoline
Based on the test data in Table 18 ■, the addition of the ester of the dimer acid of linoleic acid and diethylene glycol to methanol fuel has shown that when used in combination with the specially formulated lubricant, “Oil A, It can be seen that engine wear has been reduced to a level that is generally comparable to that obtained using commercial lubricants and premium unleaded gasoline.

Example 4 A four-ball wear test was conducted to determine the approximate wear reduction achieved using ethoxylated glycerol monocofade in methanol compared to methanol without additives. S at 800 rpm at room temperature
A load of OK) was applied for 15 minutes.

The results are presented in Table ■ below.

Table ■ None (LO77α1
Nidoxylation by volume aOos.

Addition of Gly74-monofucoate F-xylated Gly74-monofucoate resulted in a 94% reduction in wear volume.

Claims (1)

[Scope of Claim] 1, a major amount of a monohydroxyalkanol having from 1 to 5 carbon atoms, and an effective wear-reducing amount of an additive which is an ester of a monocarboxylic acid or a polycarboxylic acid and a polyhydric alcohol. , the acid has about 2 to about 3 carboxylic acid groups and about 24 to about 65 carbon atoms, and the alcohol has about 2 to about 3 carboxylic acid groups and about 24 to about 65 carbon atoms.
A fuel composition with improved wear reduction and lubricity having about 10 hydroxyl groups and about 2 to about 90 carbon atoms, wherein the ester has at least 2 free hydroxyl groups. 2. The fuel composition of claim 1 containing from about 0.0003 to about 2.0% by weight of said ester additive. 3. The fuel composition according to claim 2, wherein the alkanol is methanol. 4. The fuel composition according to claim 3, wherein the additive is a reaction product of lanolin and a polyhydric alcohol. 5. The fuel composition according to claim 4, wherein the additive is polyoxyethylene sorbitol lanolin. 6. The fuel composition according to claim 3, wherein the additive is a hydroxyl-terminated ester of polycarboxylic acid and glycol or glycerol. 7. The polyhydric alcohol is a glycol selected from the group consisting of alkanediols having from about 2 to about 12 carbon atoms or oxa-alkanediols having from about 4 to about 200 carbon atoms. Fuel compositions as described. 8. The carboxylic acid has about 9 to about 42 carbon atoms between the carboxylic acid groups.
The fuel composition according to claim 7, which is a dicarboxylic acid having carbon atoms of . 9. The fuel composition according to claim 8, wherein the polycarboxylic acid is a dimer of linoleic acid or oleic acid, or a mixture thereof, and the glycol is ethylene or diethylene glycol. 10. The fuel composition according to claim 9, wherein the additive is an ester of coconut acid and ethoxylated glycerol.