NO860348L - FUEL ADDITIVE. - Google Patents

Description

The present invention relates to a high detergent/dispersant containing additive for use with common internal combustion engine lubricants to provide a lubricant suitable for use in internal combustion engines that burn alcohol or alcohol-containing fuels such as methanol or ethanol fuel. The present invention is also directed to a lubricant mixture containing said lubricant additive, method for producing the lubricant mixture and a method for inhibiting corrosion and significant engine wear by using said lubricant mixture.

Commonly used automotive lubricants are not effective in alcohol-burning engines, which is expressed by significant engine wear and progressively increasing levels of lubricant consumption. One reason for this is the large difference in chemical reactivity of combustion products from petrol and alcohol automotive fuel systems. In an alcohol-fuel system, a number of lubricant degradation reactions occur that do not occur in a gasoline-fuel system. These chemical reactions cause the increased corrosion of alcohol fuel. For example, methanol readily oxidizes to form formaldehyde and formic acid. This reaction is represented by equation 1.

Most vehicles using methanol fuel suffer from significant corrosion of the upper cylinders and bearing wear resulting from the formic acid produced by methanol combustion. Formic acid reacts with common automotive lubricants' organic amine additives that act as antioxidants, corrosion inhibitors and antiwear agents. The amine additions neutralize the formic acid. However, common additives seem unable to adequately neutralize the amount of formic acid formed during methanol combustion.

These reactions are represented in equations 2 and 3.

Formaldehyde is highly reactive with amine additions. Formaldehyde reacts with the amines used as antioxidants, acid scavengers and ashless dispersants. These formaldehyde reactions represented by equation 4 contribute significantly to oil degradation in a methanol-fuel system.

There is a need for a lubricant additive that minimizes the oxidation of methanol to formaldehyde and formic acid and minimizes excess formaldehyde and formic acid reaction to extend the life of the lubricant additives that are rapidly removed by reaction with formaldehyde and formic acid. Similarly, there is a need for a lubricant additive that minimizes the oxidation of ethanol to acetaldehyde and acetic acid and minimizes further reactions to these components.

Another significant problem in alcohol fuel systems is that zinc dialkyldithiosulfate, an essential multi-functional additive in most lubricants, is easily transesterified and thereby loses many of its anti-wear properties. The transesterification reaction involves the exchange of an alcohol alkyl group such as methanol or ethanol with an existing ester such as zinc dialkyl dithiophosphate to form a new ester. A transesterification reaction is represented in equation 5.

The transesterification reaction is acid-catalysed and therefore occurs after the amine base additives in the lubricant have been used up by reaction with aldehydes and acids formed in the combustion process. Transesterification is not a major mechanism for oil degradation in hydrocarbon fuel systems but is a major mechanism for oil degradation in methanol and other alcohol fuel systems. For example, when methanol and ethanol are mixed with gasoline, the magnitude of the transesterification reaction is proportional to the amount of alcohol in the mixture.

Another reason for increased corrosivity in alcohol-burning engines is the increased solubility of carbon dioxide in the alcohol. For example, carbon dioxide is much more soluble in methanol than in water. Both water and methanol are usually present in the cooler parts of the crankcase as combustion products. Water reacts with fuel combustion products such as SO^, NC>2 and CO^ to form the corresponding

end acids, sulfuric acid, nitric acid and carbonic acid as represented in equations 6, 7 and 8.

These acids which react with metals in the engine are one of the main causes of corrosion in an internal combustion engine. The lubricants usually used in hydrocarbon combustion systems effectively neutralize these acids with basic additives such as organic amines and alkaline metal compounds. Meanwhile, carbon dioxide levels are significantly higher in methanol or other alcohol fuel systems than in a gasoline fuel system due to the increased solubility of CO2 in alcohols. The same can be the case for nitric acid formed from NC>2 combustion products. Absorption of carbon dioxide appears to be an important reason for the unexpected high corrosivity of alcohol fuel.

Lubricant analysis indicates that corrosion inhibitors consisting of sulfonates, naphthenates or other alkali metal salts are extensively consumed by reaction with carbonic acid and result in the precipitation of insoluble carbonates of alkali

- the metals. The precipitation reaction is represented by equations 9 and 10.

This precipitation reaction competes with the neutralization of carbonic acid by organic amines. Although the neutralization is faster and more likely to occur, the reaction with alkali metal salts increases as the organic amines are consumed. Thus, there is a need for a lubricant additive where consumption of organic amine additives due to neutralization of formic acid or acetic acid and carbonic acid takes place less quickly in order to thus reduce the probability that alkaline metal salts will be consumed by the precipitation reactions represented in equations 9 and 10.

It is a general object of the present invention to provide a lubricant additive for use in alcohol fuel burning internal combustion engines and which provides protection against corrosion and engine wear effects caused by alcohol.

It is another aim of the present invention to provide a lubricant additive with a high detergent/dispersant content to emulsify liquid alcohol threads such as methanol or ethanol added to the lubricant by exhaust gases during combustion and thereby reduce engine wear.

Another aim of the present invention is to provide a lubricant additive with increased capacity to neutralize acids.

It is a further object of the present invention to provide a lubricant additive which consists of an anti-wear agent which is not degraded by methanol or ethanol. The present invention provides a lubricant additive that can be added to common automotive lubricants that meet the minimum requirements of the American Petroleum Institute (API) for heavy oils (SF/CD) or the Committee of Common Market Automobile Constructors (CCMC) for 2.2 service grade oils and other internal combustion engine lubricants selected from the group consisting of single viscosity and multiple viscosity grade mineral and synthetic oils with an SAE of 5 to 50 to form a lubricant suitable for use in an alcohol or alcohol-containing fuel-consuming engine and comprising a major amount of an organic amine selected from the group consisting of aliphatic primary amines, aliphatic secondary amines, cycloaliphatic primary amines, aromatic primary amines, aromatic secondary amines and mixtures thereof and a small amount of a phosphoric acid ester. Preferably, the lubricant additive according to the present invention consists of approx. 68.75 to 75.0% by weight of an organic amine selected from the group mentioned above and approx. 31.25 to 25.0% by weight of a phosphoric acid ester.

The amine component of the lubricant additive according to the present invention may be an aliphatic amine, a cycloaliphatic amine, an aromatic primary amine, an aromatic secondary amine or any mixture thereof. Preferably, the amine component is an aliphatic primary or secondary amine; a cycloaliphatic primary amine; a mixture of an aliphatic primary or secondary amine or a cycloaliphatic primary amine with an aromatic primary amine, an aromatic secondary amine or both; a mixture of an aliphatic primary or secondary amine and a cycloaliphatic primary amine or a mixture of an aromatic primary amine and an aromatic secondary amine. An aliphatic primary or secondary amine alone is the most preferred amine component.

Preferred aromatic primary amines include ortho-, meta- and para-phenylenediamine, ortho-, meta- and para-toluidine, aniline, xylidine, naphthylamine, benzylamine, toluenediamine and naphthalediamine. A more preferred primary aromatic amine is ortho-phenylenediamine. Preferred aromatic secondary amines include N-phenyl-2-naphthylamine, phenyl-α-naphthylamine, phenyl-α-naphthylamine, tolylnaphthylamine, diphenylamine, ditolylamine, phenyltolylamine, 4,4'-diaminodiphenylamine and N-methylaniline. A more preferred aromatic secondary amine is N-phenyl-2-naphthylamine. Preferred aliphatic amines are aliphatic amines having 10 to 30 carbon atoms. A more preferred aliphatic amine has 12 to 30 carbon atoms. The most preferred aliphatic amine is octadecylamine. Preferred cycloaliphatic amines include cyclohexylamine and methylcyclohexylamine.

Preferred phosphoric acid esters include ortho-, meta- or para-tricresyl phosphate, dibutylphenyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, trioctyl phosphate, diphenyl ortho-phosphonate, decresyl ortho-phosphonate, trilauryl ortho-phosphonate, and tristearyl ortho-phosphonate. A more preferred phosphoric acid ester is para-tricresyl phosphate.

A preferred composition of the lubricant additive according to the present invention consists of approx. 68.75 to 75.0% by weight of octadecylamine and approx. 35.25 to 25.0% by weight of para-tricresyl phosphate.

Another preferred composition of the lubricant additive according to the present invention consists of approx. 68.75 to 75.0% by weight of octadecylamine and approx. 31.25 to 25.0% by weight of the mixed isomers of tricresyl phosphate.

All of the above-mentioned chemicals are commercially available. The lubricant additive according to the present invention is formed by mixing together a small amount of lubricant additive consisting of a major part of an organic amine selected from the group consisting of aliphatic primary amines, aliphatic secondary amines, cycloaliphatic primary amines, aromatic primary amines, aromatic secondary amines and mixtures thereof and a minor portion of a phosphoric acid ester and a major portion of a lubricant blend meeting the minimum requirements of API for SF/CD grade oils or CCMC for 2.2 service grade oils or any other lubricant blend selected from the group consisting of single or multiple viscosity grade mineral and synthetic oils with an SAE of approx. 5 to 50. The lubricant additive according to the present invention is preferably prepared by mixing together approx. 1.0 to 8% by weight of a mentioned amine, approx. 0.25 to 2.5% by weight of said phosphoric acid ester and approx. 89.5 to 98.75% by weight of said lubricant mixture.

The lubricant additive according to the present invention can be used by adding approx. 0.94 1 lubricant additive to 4.7 1 oil. The lubricant additive according to the present invention will provide effective protection against corrosion and engine wear effects caused by methanol, ethanol or other alcohol or alcohol-containing fuel for oil change intervals of more than 6400 km and in some cases up to 9600 km.

The phosphoric acid ester, preferably para-tricresyl phosphate or the mixed isomers of tricresyl phosphate, acts as a methanol or ethanol solvent and a non-ash detergent/dispersant for alcohol droplets such as methanol or ethanol in the lubricant. A solvent of this type is required to be dissolved or dispersed in a relatively large amount if alcohol such as methanol or ethanol is added to the lubricant during the combustion process in an alcohol-burning engine. The phosphoric acid ester dissolves and disperses the alcohol droplets of methanol or ethanol and thereby prevents dry spots on the moving parts of the internal combustion engine. In the absence of phosphoric acid ester, methanol or ethanol is insoluble in hydrocarbon lubricants and dry patches may occur resulting in extensive engine wear.

The phosphoric acid ester also acts as an anti-wear agent and when used with methanol or ethanol fuel it is superior to the usual anti-wear agent, zinc dialkyldithiophosphate. Zinc dialkyldithiophosphate is almost universally used in automotive lubricants for gasoline combustion engines but loses its anti-wear properties rapidly in methanol or ethanol combustion engines because it is easily transesterified with the alcohols.

The amine component acts as a base number addition to neutralize formic or acetic and carbonic acids formed by oxidation of methanol or ethanol and by the reaction of water and carbon dioxide respectively. The amine component also acts as an anti-oxidant and minimizes the oxidation of methanol or ethanol to their respective aldehydes and acids.

The presence of large amounts (about 68.75 to 75.0% by weight) of organic amines in the lubricant additive according to the present invention allows the production of a lubricant containing about 1.0 to 8.0% by weight of organic amines compared to approx. 0.25% by weight organic amines in lubricants containing common lubricant additives and minimizes the removal of alkali metal salts such as naphthenates and sulphonates. The alkali metal salts are removed when they react with carbonic acid to form insoluble carbonates and compete with the neutralization of carbonic acid. The neutralization reaction is faster and more likely to occur, but the precipitation reaction becomes a problem when the organic amines are removed. With more organic amines present, more carbon dioxide is neutralized and less carbon dioxide is available to react with the alkali metal salts.

Analysis of the lubricant after use in a car engine gives a suitable and reliable indication of engine wear during an oil change interval as short as a few thousand kilometres.

The lubricant addition can be assessed based on the amounts of wear elements such as iron, lead, copper, chromium, nickel, tin, aluminum and molybdenum detected in an oil sample by spectrochemical analysis after the engine has been driven a number of miles after an oil change. These metals or wear elements appear in the lubricant as a result of extensive corrosion of or failure of individual engine components made of this metal as well as normal mechanical wear.

Since the materials for the construction of cars vary greatly, it is not technically possible to determine exactly which wear element content in an applied oil analysis indicates extensive engine wear. However, general criteria for evaluating lubricant wear elements are available and are listed in Table 1. The primary and secondary sources in the engine for each wear element are given as well as the average amount in ppm of each wear element that will be found in the oil in the run-in period and the post-run-in period. Engine wear levels during the break-in period tend to be relatively high. After the engine is broken in, wear levels reach a plateau and remain stable for approx. 80,000 km depending on the special vehicle and the degree of maintenance. The break-in period for an average engine is usually in the order of 0 - 15,000 km. The assessment criteria shown in table 1 can be used to assess the data given in examples 1-13.

The most useful indication of extensive engine wear is from sudden deviations in a given wear element content in a used oil analysis pattern that has previously been established for a given engine in a given service using a particular oil.

Base number is a measure of the oil detergent effect and its property to prevent corrosion. New automotive oils usually have a base number of 4 - 5. For any oil, a number of 1 or less indicates a dangerous consumption that additive reserves. A base number of 2 is generally believed to provide a suitable margin of safety in a petrol engine.

Criteria for evaluating lubricant wear element data

Example 1

An oil sample consisted of approx. 98.68% by weight Kendall TM 40% by weight automotive lubricant and approx. 1.32% by weight of the lubricant additive according to the present invention consisting of approx. 75.0% by weight octadecylamine and approx. 25.0% by weight paratricresyl phosphate was taken from the crankcase of a methanol-using 1981 Chevrolet Citation engine that had been driven 146,962 km with an oil change at approx. every 6450 km previously. The methanol fuel used was an 88.0% methanol/12.0% unleaded regular gasoline (87 octane) blend.

The oil sample with a base number of 3.14 which is well above the acceptable base number value of 2 and which indicates that octadecylamine had not been removed and was still available to neutralize acids and prevent oxidation of methanol to form formic acid and formaldehyde.

Spectrochemical analysis showed that the following amounts of wear elements were present in the oil sample: 25 ppm iron; 49 ppm lead; 83 ppm copper; 1 ppm chromium; 3 ppm aluminium; 1 ppm nickel; 15 ppm tin and 2 ppm molybdenum. Because the engine had been driven 146,926 km, the run-in criteria from the table were used to assess the wear element content.

Referring to Table 1, the iron, lead, chromium, aluminum nickel and molybdenum contents were within the average wear element content range for these wear elements at the post run-in stretch. The copper content was above average but not significant. According to table 1, the tin content was considered to be high, however, the tin content in the oil sample taken from the crankcase during the oil change at 6450 km before the present oil change was 14 ppm, which indicates no significant change in the tin content and thus no significant engine wear. As mentioned earlier, a sudden deviation of wear element content in a used oil analysis indicates better engine wear than the generalized criteria in table 1.

Example 2

An oil sample consisting of 98.68% by weight of the lubricant used in Example 1 and 1.32% by weight of the lubricant additive used in Example 1 was taken from the crankcase of the same methanol-driven engine as in Example 1. The engine had been run 153,128 km and thus the previous oil change took place 6202 km earlier.

The oil sample had a base number of 2.8 which is well above the acceptable base number value of 2 and indicates that the octadecylamine content had not been depleted.

Spectrochemical analysis showed that the following amounts of wear elements were present in the oil sample: 34 ppm iron; 72 ppm lead; 95 ppm copper; 0 ppm chromium; 4 ppm aluminium; 1 ppm nickel; 19 ppm tin and 3 ppm molybdenum. The criteria for post-run-in from table 1 were applied.

Referring to Table 1, the iron, lead, chromium, aluminum and nickel contents were within the average wear element range for these wear elements at the post-run-in stretch. The copper content was above average but not large and had not significantly deviated from the previous copper content described in example 1. The tin and molybdenum content was considered to be large according to table 1 but there was no significant deviation from the previous tin and molybdenum content described in example 1 and thus indicating no major engine wear.

Example 3

An oil sample consisting of approx. 98.68% by weight of the lubricant used in examples 1 and 2 and approx. 1.32% by weight of the lubricant additive used in Examples 1 and 2 was taken from the crankcase of the same methanol powered engine used in Examples 1 and 2 which had been driven 159,285 km. Thus, the previous oil change took place approx. 6157 km before the current oil change. The sample had a base number of 3.02 indicating that the octadecylamine had not been removed.

Spectrochemical analysis revealed the following amounts of wear-as j e elements to be present in the oil sample: 20 ppm iron; 49 ppm lead; 97 ppm copper; 1 ppm chromium; 2 ppm aluminum; 2 ppm nickel; 19 ppm tin and 2 ppm molybdenum. The sample was assessed using the post-run-in criteria from Table 1.

With reference to Table 1, the iron, lead, chromium, aluminium, nickel and molybdenum content was within the average wear element content range for these wear elements at the post-run-in stretch. The copper content was above average but not great. The tin content was considered to be high according to table 1, however there was no change at all from the previous oil change and thus there was no indication of extensive engine wear.

Example 4

An oil sample consisting of approx. 98.68% by weight of Kendall 30 wt automotive lubricant and approx. 1.32% by weight of the lubricant additive according to the present invention consisting of approx. 75.0 wt% octadecylamine and 25.0 wt% paratricresyl phosphate were taken from the crankcase of a methanol fueled 1982 Chevrolet S-10 engine that had been run approx. 128,358 km with an oil change at approx. every 6500 km. The methanol fuel used was an 88.0% methanol/12.0 unleaded regular gasoline (87 octane) blend.

The base number of the sample was 2.52 indicating that the octadecylamine had not been removed.

Spectrochemical analysis showed that the following amounts of wear elements were present in the oil sample. 96 ppm iron; 27 ppm lead; 49 ppm copper; 3 ppm chromium; 14 ppm aluminium; 2 ppm nickel; 5 ppm tin and 7 ppm molybdenum. The run-in criteria from table 1 were used because 128,358 km repre-

enters an after-run stretch.

With reference to Table 1, the iron, lead, copper, chromium, aluminium, nickel and tin content were within the average wear element content for these wear elements at the post-run-in stretch. The molybdenum content was considered to be high according to table 1, but as shown in examples 5 and 6 below, there was no sudden deviation in the molybdenum content at the various oil changes and thus there was no indication of heavy engine wear.

Example 5

An oil sample consisting of approx. 98.68% by weight of the lubricant used in example 4 and approx. 1.32% by weight of the lubricant additive used in Example 4 was taken from the crankcase of the same methanol-powered engine used in Example 4 which had been driven 135,144 km. Thus, the previous oil change took place approx. 6751 km before the current oil change.

The oil sample had a base number of 1.93 which is very close to the acceptable base number value of 2 and thus indicated sufficient amounts of octadecylamine to neutralize acids and minimize methanol oxidation.

Spectrochemical analysis showed that the following amounts of wear elements were present in the oil sample: 57 ppm iron; 26 ppm lead; 42 ppm copper; 2 ppm chromium; 16 ppm aluminium; 2 ppm nickel; 0 ppm tin and 18 ppm molybdenum. The follow-in criteria from table 1 were used.

With reference to Table 1, the iron, lead, copper, chromium, nickel and tin content were within the average wear element content range for these wear elements at the post run-in stretch. The aluminum content was slightly above average but not large. The molybdenum content is considered to be high according to table 1, but had not changed significantly from the content at the last oil change and indicated

no major engine wear.

Example 6

An oil sample consisting of approx. 98.68% by weight of the lubricant used in examples 4 and 5 and approx. 1.32% by weight of the lubricant additive used in Examples 4 and 5 was taken from the crankcase of a methanol fueled engine used in Examples 4 and 5 which had been driven the equivalent of 142,409 km. Thus, the previous oil change took place approx. 7264 km before the current oil change.

The base number for the sample was approx. 1.62 which is somewhat lower than the more acceptable numerical value of 2 but is still greater than 1 and thus indicates that sufficient amounts of octadecylamine were present.

■Spectrochemical analysis showed that the following amounts of wear elements were present in the oil sample: 71 ppm iron; 22 ppm lead; 41 ppm copper; 1 ppm chromium; 16 ppm aluminium; 1 ppm nickel; .0 ppm tin and 34 ppm molybdenum. The run-in criteria from table 1 could be used to assess the oil sample because 142,409 km is considered to be a run-in stretch. ■

Referring to Table 1, the iron, lead, copper, chromium, nickel and tin wear element contents were within the average wear element content range for the run-in section. The aluminum content was above average but not large. The molybdenum content was considered to be high according to table 1, but the molybdenum content had not changed significantly from the content at both previous oil changes and indicated no major engine wear.

Example 7

Eh oil sample consisting of approx. 98.68% by weight of Kendall<TM>

30 wt automotive lubricant and approx. 1.32% by weight of lubricant according to the present invention consisting of approx. 75.0% by weight octadecylamine and approx. 25.0 wt% paratricresyl phosphate was taken from the crankcase of a methanol fueled 1982 Chevrolet S-10 engine that had been driven 123,330 km with an oil change at approximately every 5216 km prior to this. The methanol fuel used was an 88.0 methanol/12.0% unleaded regular gasoline (87 octane) blend.

The oil sample had a base number of 3.3 which is well above the acceptable base number value of 2 and indicated that the octadecylamine had not been removed and was still available to neutralize acids and minimize methanol oxidation.

Spectrochemical analysis showed that the following amounts of wear elements were present in the oil sample: 50 ppm iron; 10 ppm lead; 56 ppm copper; 2 ppm chromium; 9 ppm aluminium; 0 ppm nickel; 0 ppm tin and 3 ppm molybdenum. The run-in criteria from table 1 were used to assess the oil sample because 123,330 km represents a run-in stretch.

Referring to Table 1, the iron, lead, copper, chromium, aluminium, nickel and tin contents were within the average wear element content range for these wear elements at the post-run-in stretch. The molybdenum content was considered to be high according to table 1, but as shown in examples 8 and 9 below, there was no sudden deviation in the molybdenum content at the various oil changes and thus indicated no major engine wear.

Example 8

An oil sample consisting of approx. 98.68% by weight of the lubricant used in example 7 and approx. 1.32% by weight of the lubricant additive used in Example 7 was taken from the crankcase of the same methanol-powered engine used in Example 7 which had been driven 130,670 km. Thus, the previous oil change took place at approx. 7340 km before the current oil change.

The base number of the oil sample was 3.64 which is well above the acceptable base number value of 2 and indicated that the octadecylamine had not been removed.

Spectrochemical analysis showed that the following amounts of wear elements were present in the oil sample: 39 ppm iron; 9 ppm lead; 27 ppm copper, 2 ppm chromium; 7 ppm aluminium; 0 ppm nickel; 0 ppm tin and 11 ppm molybdenum.

The iron, lead, copper, chrome, aluminium, nickel and tin contents were within the average wear element content range for these wear elements at the post-run-in stretch. The molybdenum content was considered to be large according to table 1, but there was no sudden deviation from the content at the previous oil changes described in example 7 and thus indicated no major engine wear.

Example 9

An oil sample consisting of approx. 98.86% by weight of the automotive lubricant used in examples 7 and 8 and approx. 1.32% by weight of the lubricant additive used in Examples 7 and 8 was taken from the crankcase of the same methanol fueled engine used in Examples 7 and 8 which had been driven 137,355 km. Thus, the previous oil change took place approx. 6685 km before the current oil change.

The base number of the oil sample was 3.36 which is well above the acceptable base number value of 2 and indicated that the octadecylamine had not been removed.

Spectrochemical analysis showed that the following amounts of wear elements were present in the oil sample: 39 ppm iron; 9 ppm lead; 94 ppm copper; 2 ppm chromium; 7 ppm aluminium; 1 ppm nickel; 0 ppm tin and 12 ppm molybdenum. The sample was assessed using the post-run-in criteria from Table 1.

With reference to Table 1, the iron, lead, chromium, aluminium, nickel and tin contents were within the average wear element content range for these wear elements at the post run-in stretch. The copper content was above average but not much. The molybdenum content was considered to be high according to table 1 but only increased 1 ppm from the previous oil change described in example 8 and thus indicated no major engine wear.

Example 10

An oil sample consisting of approx. 98.68% by weight Kandall TM 30 wt. automotive lubricant and approx. 1.32% by weight of the lubricant additive according to the present invention consisting of approx. 75.0% by weight octadecylamine and approx. 25.0% by weight paratricresyl phosphate was taken from the crankcase of the methanol-fueled 1982 Chevrolet S-10 engine which had been run correspondingly approx. 126,510 km with an oil change approx. every 6,849 km before this. The methanol fuel used was an 88.0% methanol/- 12.0% unleaded regular gasoline (octane no. 87) mixture.

The base number for the oil sample was approx. 3.02 which is well above the acceptable base number value of 2 and indicates that the octadecylamine had not been removed.

Spectrochemical analysis showed that the following amounts of wear elements were present in the oil sample: 130 ppm iron; 15 ppm lead; 69 ppm copper, 4 ppm chromium; 14 ppm aluminium; 2 ppm nickel; 5 ppm tin and 11 ppm molybdenum. The oil sample was assessed using the run-in distance criteria in table 1 because 126,510 km represents a run-in distance.

With reference to Table 1, the lead, copper, chromium, aluminium, nickel and tin contents were within the average wear element content range for these wear elements at the post-run-in stretch. The iron content was above average but not much. The molybdenum content was large according to table 1, but as shown in examples 11 and 12, the molybdenum content did not suddenly deviate from the established pattern at any of the different oil changes and thus indicated no major engine wear.

Example 11

An oil sample consisting of approx. 98.68% by weight of the lubricant used in example 10 and approx. 1.32% by weight of the lubricant additive used in Example 10 was taken from the crankcase of the same methanol-driven engine used in Example 10 which had been driven 131,897 km. Thus, the previous oil change took place approx. 5386 km before the current oil change.

The base number of the oil sample was 3.36 which is well above the acceptable base number value of 2 and indicated that the octadecylamine had not been removed.

Spectrochemical analysis showed that the following amounts of wear elements were present in the oil sample: 63 ppm iron; 10 ppm lead; 83 ppm copper; 3 ppm chromium; 9 ppm aluminium; 2 ppm nickel; 0 ppm tin and 31 ppm molybdenum. The post-run-in criteria from table 1 were used to assess the oil sample.

With reference to Table 1, the iron, lead, chromium, aluminium, nickel and tin contents were within the average wear element content range for these wear elements at the post run-in stretch. The copper content was above average but not much. The molybdenum content was considered to be high according to table 1, but did not deviate significantly from previous molybdenum content at previous oil changes as described in example 10. Thus, the molybdenum content does not indicate high engine wear. Furthermore, the iron, lead, chrome, aluminum and tin content decreased from example 10 to example 11, which indicates that the lubricant additive according to the present invention effectively inhibits corrosion and engine wear.

Example 12

An oil sample consisting of approx. 98.68% by weight of the lubricant used in examples 10 and 11 and approx. 1.32% by weight of the lubricant additive used in Examples 10 and 11 was taken from the crankcase of the same methanol fueled engine used in Examples 10 and 11 which had been driven 138,807 km. Thus, the previous oil change took place approx. 6910 km before the current oil change.

The base number for the oil sample was approx. 2.91 which is well above the acceptable base number value of 2 and indicated that the octadecyl amine had not been removed and was still available to neutralize acids and prevent oxidation of methanol to formaldehyde and formic acid.

The spectrochemical analysis showed that the following amounts of wear elements were present in the oil sample: 70 ppm iron; 8 ppm lead; 22 ppm copper; 1 ppm chromium; 12 ppm aluminium; 0 ppm nickel; 0 ppm tin and 17 ppm molybdenum. The oil sample was assessed using the post-run-in criteria from Table 1.

With reference to Table 1, the iron, lead, copper, chromium, aluminium, nickel and tin contents were within the average wear element content range for these wear elements at the post-run-in stretch. The molybdenum content was considered to be high according to Table 1 but had decreased since the previous oil change described in Example 11 and thus indicated that the lubricant addition is effective in preventing corrosion and heavy engine wear. Furthermore, the lead, copper, chromium and nickel contents decreased from the previous oil change assessment described in example 11 and the iron, lead, copper, chromium, nickel and tin contents decreased from the previous oil change described in example 10, which indicated that the lubricant additive according to the present invention effectively inhibits corrosion and high engine wear in methanol-powered engines.

Example 13

The average base number in the oil sample assessments described in examples 1 to 12 was 3.15, which is well above the acceptable base number value of 2.

Average wear element content in the oil sample evaluations described in Examples 1 to 12 are as follows: 57.8 ppm iron; 25.5 ppm lead; 63.2 ppm copper; 1.8 ppm chromium; 9.4 ppm aluminium; 1.2 ppm nickel; 5.25 ppm tin and 12.5 ppm molybdenum.

All of the above-mentioned wear element content data representing average data from previous 12 examples were within the average wear element content range shown in Table 1 for the post-run-in section except for molybdenum. However, large amounts of molybdenum as described in the previous 12 examples did not indicate high engine wear because there were never any sudden deviations from the pre-established used oil rating patterns.

The average values for base number and wear element content described herein illustrated that the lubricant additive according to the present invention effectively inhibits corrosion and heavy engine wear in necessary internal combustion engines that use alcohol or alcohol-containing fuel.

Claims (29)

1. Lubricant additive for use in internal combustion engines using alcohol or alcohol-containing fuel, characterized in that it consists of a major part of an organic amine component selected from the group consisting of aromatic primary amines, aromatic secondary amines, aliphatic primary amines, aliphatic secondary amines, cycloaliphatic primary amines and mixtures thereof and a small part of a phosphoric acid ester. 2. Lubricant additive according to claim 1, characterized in that the amine content is approx. 68.75 to 75.0% by weight and that the phosphoric acid ester content is approx. 25.0 to 31.25% by weight. 3. Lubricant additive according to claim 1, characterized in that the amine component is a mixture consisting of an aliphatic primary amine and an amine selected from the group consisting of aromatic primary amines, aromatic secondary amines and mixtures thereof. 4. Lubricant additive according to claim 1, characterized in that amine components are a mixture consisting of an aliphatic secondary amine and an amine selected from the group consisting of aromatic primary amines, aromatic secondary amines and mixtures thereof. 5. Lubricant additive according to claim 1, characterized in that amine components are a mixture consisting of a cycloaliphatic primary amine and an amine selected from the group consisting of aromatic primary amines, aromatic secondary amines and mixtures thereof. 6. Lubricant additive according to claim 1, characterized in that the amine component is an aliphatic primary amine. 7. Lubricant additive according to claim 1, characterized in that the amine component is an aliphatic secondary amine. 8. Lubricant additive according to claim 1, characterized in that the amine component is a mixture consisting of an aliphatic primary amine and a cycloaliphatic primary amine. 9. Lubricant additive according to claim 1, characterized in that the amine component is a mixture consisting of an aliphatic secondary amine and a cycloaliphatic primary amine. 10. Lubricant additive according to claim 1, characterized in that the amine component consists of a cycloaliphatic primary amine. 11. Lubricant additive according to claim 1, characterized in that the amine component is a mixture consisting of an aromatic primary amine and an aromatic secondary amine. 12. Lubricant additive according to claim 1, characterized in that the aromatic primary amine is selected from the group consisting of ortho-phenylenediamine, meta-phenylenediamine, para-phenylenediamine, ortho-toluidine, meta-toluidine, para-toluidine, aniline, xylidine, naphthyl -amine, benzylamine, toluenediamine and naphthalenediamine. 13. Lubricant additive according to claim 12, characterized in that the aromatic primary amine is ortho-phenylenediamine. 14. Lubricant additive according to claim 1, characterized in that the aromatic secondary amine is selected from the group consisting of N-phenyl-2-naphthylamine, phenyl-a-naphthylamine, phenyl-phen-naphthylamine, tolyl-naphthylamine, diphenylamine , ditolylamine, phenyltolyamine, 4,4'-diaminodiphenylamine and N-methylaniline. 15. Lubricant additive according to claim 14, characterized in that the aromatic secondary amine is N-phenyl-2-methylamine. 16. Lubricant additive according to claim 1, characterized in that the aliphatic amine is an aliphatic amine with 10 to 30 carbon atoms. 17. Lubricant additive according to claim 16, characterized in that the aliphatic amine is octadecylamine. 18. Lubricant additive according to claim 1, characterized in that the cycloaliphatic amine is selected from the group consisting of cyclohexylamine and methylcyclohexylamine. 19. Lubricant additive according to claim 1, characterized in that the phosphoric acid ester is selected from the group consisting of ortho-tricresyl phosphate, meta-tricresyl phosphate, para-tricresyl phosphate, dibutylphenyl phosphate, tributyl phosphate, tri-2-ethylhexyl phosphate, trioctyl phosphate, diphenyl, ortho-phosphonate, dicresyl ortho-phosphonate, trilauryl ortho-phosphonate and tristearyl ortho-phosphonate. 20. Lubricant additive according to claim 19, characterized in that the phosphoric acid ester is para-tricresyl phosphate. 21. Method for inhibiting corrosion and heavy engine wear in an internal combustion engine that uses alcohol or alcohol-containing fuel, characterized in that it consists in adding to the engine an internal combustion engine lubricant selected from the group consisting of single viscosity and multiple viscosity grade mineral and synthetic oils with a SAE of approx. 5 to 50 wherein the lubricant containing a lubricant additive consisting of a major portion of an organic amine component selected from the group consisting of aromatic primary amines, aromatic secondary amines, aliphatic primary amines, aliphatic secondary amines, cycloaliphatic primary amines and mixtures thereof and a small amount of a phosphoric acid ester. 22. Method according to claim 21, characterized in that the amine content of the lubricant additive is approx. 68.75 to 75.0% by weight and that the phosphoric acid ester content of the lubricant additive is approx. 25.0 to 31.25% by weight. 23. Method according to claim 21, characterized in that the lubricant contains approx. 1.25 to 10.5% by weight of the lubricant additive. 24. Method of producing an internal combustion engine lubricant that inhibits corrosion and heavy engine wear in an internal combustion engine using alcohol or alcohol-containing fuel, characterized by the step of mixing together a bulk amount of an internal combustion engine lubricant selected from the group consisting of single viscosity and multiple viscosity grade mineral and synthetic oils with an SAE of approx. 5 to 50 and a small amount of a lubricant additive consisting of a major amount of organic amine component selected from the group consisting of aromatic primary amines, aromatic secondary amines, aliphatic primary amines, aliphatic secondary amines, cycloaliphatic primary amines, cycloaliphatic secondary amines and mixtures thereof and a small amount of a phosphoric acid ester. 25. Method according to claim 24, characterized in that the amine content in the lubricant additive is approx. 68.75 to 75.0% by weight and that the phosphoacid ester content of the lubricant additive is approx. 25.0 to 31.25% by weight. 26. Method according to claim 24, characterized in that approx. 89.5 to 98.75% by weight of the lubricant and approx. 1.25 to 10.5% by weight of the lubricant additive is mixed together. 27. Lubricant composition that inhibits corrosion and heavy engine wear in an internal combustion engine using alcohol or alcohol-containing fuel, characterized in that it consists of a major amount of an internal combustion engine lubricant selected from the group consisting of single viscosity and multiple viscosity grade mineral and synthetic oils with an SAE of approx. 5 to 50 and a small amount of a lubricant additive consisting of a major amount of an organic amine component selected from the group consisting of aromatic primary amines, aromatic secondary amines, aliphatic primary amines, aliphatic secondary amines, cycloaliphatic primary amines, cycloaliphatic secondary amines and mixtures thereof and a small amount of a phosphoric acid ester. 28. Lubricant mixture according to claim 27, characterized in that the amine content of the lubricant additive is approx. 68.75 to 75.0% by weight and the phosphoric acid ester content of the lubricant additive is approx. 25.0 to 31.25% by weight. 29. Lubricant mixture according to claim 27, characterized in that the lubricant content is approx. 89.5 to 98.75% by weight and the lubricant additive content is approx. 1.25 to 10.5% by weight.