DE2528513A1 - Ester lubricating oils prepd from cyclic polycarboxylic acids - for use in two stroke engines - Google Patents

Abstract

Lubricants contg. (A) polycarboxylic acid ester(s) of low volatility which are liquid at room temp., (b) high-pressure additive(s), (C) corrosion inhibitor(s) and opt. (D) other usual additives. Used as motor or gear oils, and esp. in two-stroke engines, mixed with the fuel in ratio of at least 1:200. Compsns. can be used at dilutions of below 1:100 instead of the usual 1:20-30, while giving satisfactory lubrication under all loads. Problems of rapid spark plug wear are much reduced or eliminated. Smoke emission and water pollution, e.g. from boat engines, is reduced. Suitably the ester is derived from tri-or pyro-mellitic acid and/or a cyclo-octene tetracarboxylic acid, and a 5-10C alkanol e.g. the 2-ethyl hexyl ester of 1, 4-etheno cyclohexane tetracarboxylic acid.

Description

Lubricants "The invention relates to lubricants containing at least an ester oil as the base oil, at least one high-pressure additive and at least one corrosion protection additive as well as other common lubricant component (s), if applicable.

It is well known that ester oils have long been used as base oils for lubricants used and have proven themselves particularly well with various special lubricants proven and often proven to be clearly superior to mineral lubricating oils. Also with Ester oils could, however, be used in two-stroke explosion engines and especially two-stroke engines Problems occurring with a high specific power, such as rapid plug wear, Overheating, pre-wear on the moving engine parts, piston seizure and the characteristic Two-stroke smoke, bichr can not yet be solved satisfactorily. In particular that the latter phenomenon, which is essentially due to the discharge of unburnt or only incompletely burned lubricating oil is based on the exhaust gases and with two-stroke engine, which the lubricating oil is usually in the form of a premixed lubricating oil / Fuel mixture is supplied, is known to be particularly pronounced, represents a so far nocb not satisfactory yellow problem that has contributed significantly to that the two-stroke engine, despite a number of undeniable merits, is increasing in ours environmentally conscious time lost considerably in importance liat.

Attempts were able to solve this problem by means of separately controllable ones To solve fuel and lubricating oil supply, the advances made so far in the development of more efficient ones, i.e. also with smaller lubricating oil / fuel ratios Two-stroke oils that guarantee sufficient lubrication under all operating conditions to change something, since the lubricating oil supply is regulated independently of the fuel supply is too expensive and the further development of lubricating oils so far has made it possible the previously common lubricating oil / fuel mixture ratios of about 1:20 to 1: 30 to about 1:40 to 1: 60, even the "leanest" currently usable However, two-stroke mixtures are still strong in a number of operating conditions Pre-combustion gases contaminated with lubricating oil provide, which indisputably a considerable Represent environmental pollution.

This is especially true of the exhaust gases from two-boat engines because the lubricating oil residues in it do not distribute evenly and quickly, but only covering large areas on the surface of the water, even in small valleys, collect thin but tightly closed films of oil.

The invention was therefore based on the object of a new lubricant to create properties that are particularly superior as a two-stroke lubricating oil and, among other things, even at low mixing ratios that have not been attainable so far of 1: 100 and more wavy under all operating conditions sufficient lubrication guaranteed.

It has now been found that, surprisingly, this task can be solved by certain ester oils, namely liquid at room temperature, low-volatility esters of cyclic polycarboxylic acids used as base oil.

The invention therefore relates to a lubricant of the initially introduced designated type, which is characterized in that it is an ester oil at least a non-volatile ester of a cyclic polycarboxylic acid that is liquid at room temperature (Polycarboxylic acid ester) contains.

The lubricants of the invention have a wide variety of uses, so z.fl. as engine oils for four-stroke engines, gear oils and die lubricants, excellent properties, with the base oil and additives each being optimal must be matched to the respective application, which the skilled person, however is given without further ado. However, their special abilities come into play above all else the use of lubricating oils for two-stroke engines (two-stroke oils) to wear. As two-stroke oils are the invention Lubricating oils all so far for this Purpose known motor oils are far superior to the fact that they are in little also not nearly reached lubricating oil / fuel duplicates of less than 1: 100 and in many cases even 1: 200 and below even with continuous full load and others Operating conditions difficult to control in terms of lubrication in two-stroke engines including idling, absolutely reliable lubrication even in high-performance engines guarantee.

Another surprising advantage is that it can be used as a two-stroke oil erfindungsgcmä.ßer lubricant can be seen in the fact that they are for two-stroke engines Significantly reduce or even completely eliminate typical spark plug problems. Furthermore is to point out that the lubricants of the invention are essential to the environment and in particular are more water-friendly than the more common ones, e.g. for boat engines Two-stroke oils.

Further advantages and features of the invention will become apparent to those skilled in the art from the following description of preferred embodiments, an embodiment and the results with the lubricant of the embodiment motor and biological tests.

Those in the lubricants according to the invention as a knowledgeable component Ester oils contained are preferably derived from cyclic polycarboxylic acid 3 to 5 carboxyl groups.

It has proven to be particularly suitable for the purposes of the invention Ester oils derived from polycarboxylic acids with at least one five- to seven-membered ring in the molecule.

In particular, ester oils that differ from cyclic polycarboxylic acids with Derive at least one double bond in the ring are for the purposes of the invention suitable. Furthermore, it should be pointed out in this context that as base oils ester oils are preferably used for lubricants according to the invention, which are from cyclic polycarboxylic acids with carboxyl groups bonded directly to ring carbon atoms are derived, the best results with trimellitic, pyromellitic and cyclooctentetracarboxylic acid esters, in particular esters of 1,4-ethenocyclohexanetetracarboxylic acid were obtained.

The ester oils used as base oils according to the invention can basically be derived from all aromatic or aliphatic alcohols, their esters with the respective cyclic polycarboxylic acids are liquid at room temperature and are relatively volatile, but are of aliphatic monohydric alcohols Derived ester oils are preferred, Estrels with - preferably branched-alkyl radicals with 5 to 10 carbon atoms and in particular 2-ethylhexyl ester bischer best have proven themselves.

As already mentioned, the lubricants of the invention contain at least One high-pressure and one anti-corrosion additive each.

Commercially available sulfur are particularly suitable as an additional high pressure and products containing phosphorus, in particular one commercially available EP additive made from a sulfurized mixture of natural and synthetic fatty esters and at least one phosphorus sulfur alkyl amide.

As the corrosion inhibitor, the lubricants of the invention are preferred Zinc-containing commercial products added. There is one for two-stroke oils a commercially available corrosion protection additive based on zinc complex soaps and / or -salts particularly proven.

The high pressure additives are expediently in amounts of about 0.2 to 6, preferably 0.4 to 3 and in particular 0.8 to 1.2 percent by weight based on the total weight of the lubricant, with a value in the latter Has particularly proven itself in the area of two-tier oils.

I) he corrosion additives are expediently in amounts of about 0.01 to 5, preferably about 0.1 to 2.5 and in particular about 0.6 to 1.4 percent by weight, based on the total weight of the lubricant.

The exemplary embodiment explains a particularly as a two-stroke oil suitable lubricant according to the invention and its essential advantages as a two-stroke oil compared to conventional, proven two-stroke oils.

13 e i s p 1 e 1 1 liter 1,4-etheno-cyclohexane-tetracarboxylic acid tetra- (2-ethylhexyl ester) became more natural with 10 ml of a high pressure additive from a sulfurized mixture and synthetic fatty esters and sulfur phosphoralkylamides and 8 ml of an anti-corrosive additive Zinc complex soaps and salts are added to the base and mixed with them.

1> as obtained in this way according to the invention to be used as a two-kettle oil Lubricant, hereinafter referred to as "lubricating oil ZX 2", was obtained from the FHS-Konstanz, Laboratory and discipline combustion engine, following sharp motor tests subject: To carry out the first engine test, a two-cylinder, two-stroke Outboard motor of the i'a. Johnson, Type Johnson 6, outboard, used that with was equipped with a test screw customary for test Ilufe in the test tank.

The engine was brand new at the beginning of the test run and with the usual one Preservative protected against corrosion by river and sea water. He pointed the daily run-in marks on a brand-new engine. To carry out During the test run, the engine was fitted with new spark plugs from Champion des from Johnson company of the type recommended for this engine. I) he was on an engine Longitudinal edge of a mobile test water tank with a water capacity of 500 Liters attached. The fuel was in one below the test water tank The fuel tank placed on an intermediate shelf was filled with all was sucked in by a non-clean fuel pump.

To carry out the 1'rLiflauf, a two-stroke mixture atis 60 Liters of commercial petrol and 300 ml ZX 2 lubricating oil produced, corresponding to a lubricating oil / fuel mixture ratio of 1 s 200.

In order to get a meaningful preliminary result quickly, a test run of 6 hours at a speed of 4800 @ / min. at idle drove. Then the spark plugs were unscrewed and examined. It showed that no electrode debris could be found, all the spark plugs were inserted typical 4-stroke candle pattern and only fine salt pearls on the electrodes were present.

For further testing, a 12-hour continuous run was completed with the switched on Forward gear and a speed of 4600 rpm, with no running problems and in particular no misfires, which were signs of coking or mechanical wear could have been seen. It should be pointed out that the engine is already in this at the applied mixing ratio of 1 s 200 According to experience, the test stage is unusable with a probability bordering on certainty would have been if instead of the lubricating oil according to the invention one of the currently used, commercially available Two-stroke oils would have been used.

After 18 hours of continuous running, switching between forward and reverse gear as well as Frei 1, whereby no irregularities could be detected, the Spark plugs changed and used spark plugs analyzed. They showed as before the typical 4-stroke candle pattern and therefore showed only extremely low signs of wear on. In particular, no measurable electrode erosion could be determined, i.e. that the electrode spacing, as prescribed for new candles, remains unchanged Was 0.75 mm. In order to simulate alternating operation, the test engine was up after 12 hours been stalled and the candles were changed.

The test run was canceled after a 24-hour continuous run.

According to this, the test motzor did not show any excessive pre-wear characteristics and showed no malfunctions when started and stopped several times. To complete Evaluation of the test run, the test engine was then: Lm laboratory carefully and professionally disassembled.

The following results were found: a) Visual assessment the pistons and especially the first piston rings: the original labyrinth grooves the outer surfaces of the ring were only slightly worn and were still clearly recognizable.

The piston skirt was also not attacked and also on the print or system side not cleared.

b) Needle roller bearings (plenary crank bearings): The bearing shells had a clearly recognizable protective film and showed no signs of wear.

The running needles or roller needles also showed one under the microscope thin protective film with excellent emergency running properties were completely undamaged and absolutely free of damage, discoloration or even carbonization, so dnf der Overall running condition was excellent.

c) Piston pin and connecting rod pin eye: These engine parts also showed the same good running image.

d) Crankshaft and associated bronze bearings: The crankshaft of the test engine is cranked once and three times in bronze plain bearings against the crankshaft journal mounted, the Flronzegleitlager directly into the vertical in the crankshaft center Die-cast housings divided to the cylinder axis are cast.

The crankshaft and bronze bearings were practically undamaged after the test and still showed the wear marks of the bearing processing tool.

Only at the edge was worn, and only here did the typical ones appear Ring call features, but no confirmation. There were no traces of rust to be found.

e) Cylinder block and cylinder: Deviating from the usual Dild was no coking of the exhaust slots to recognize. Next were no Debris from the cylinder walls and no corrosion from rust or other chemical substances Determine influences.

f) Cylinder head: I) the combustion chambers showed one of those ou: I wise Second-fuel burners heavily soiled with oil, a completely different picture and only had small deposits of those normally found in 1-liter electric motors Type and amount.

g) Spark plugs: The spark plugs, after all, a 6-hour endurance run had behind them, there was no overburden and no covering. The ignition surfaces the electrodes were bare metal.

In addition, the condition of the water in the test water tank was monitored .

It turned out that nowhere the usual traces of oil and black Oil carbon or oil sludge deposits were found. Rather, they could only the combustion products that are common with four-stroke engines and the products that are passed through Percentage of airborne particles can be determined.

To further safeguard this excellent result, a 3-hour test run in a two-stroke model aircraft engine of the T3rpe WEflR 10 ccm performed, the lubricating oil ZX2 the fuel, pure methyl alcohol, again added in a mixing ratio of 1: 200. The test run was at a speed of 20,000 11 / min., corresponding to a piston speed of 14.66 m / s. After the test run, the piston did not show any reduction in compression leading wear on. The crankshaft showed an excellent running pattern, that which usually corresponded to a running time of only 10 to 12 minutes from the new state. The main ball bearing had run in well in its radial play, but internally of tolerance. The platinum glitter candle was also undamaged and oil-free, so that the The engine started again immediately when trying to start again.

Finally, a comparative experiment was carried out to determine the water biological Properties performed z.

To do this, one liter of water from the lake was mixed with 1 ml of lubricating oil ZX or of a commercially available two-stroke lubricating oil and placed in a glass stand cylinder filled. A few water plants and water snails were placed in each of the standing cylinders used. During the stocking in the contaminated with commercial two-stroke lubricating oil Water had died after just a few days and began to rot the Hesatz in the mixed with the lubricant according to the invention water undisturbed for several months and the water snails even multiplied.

Claims (1)

P a t e n t a n s p r ü c h e 1. Lubricant containing at least one ester oil as base oil, at least a puncture pressure additive and at least one corrosion protection additive and, if applicable other common lubricant component (s), thus not marked that it is called ester oil. at least one which is liquid at room temperature and is of low volatility Contains ester of a cyclic polycarboxylic acid (polycarboxylic acid ester). 9. Lubricant according to claim 1, characterized in that it is as It teröl at least one polycarboxylic acid ester of a polycarboxylic acid with 3 to 5 Contains carboxyl groups. 3. Lubricant according to claim 1 or 2, characterized in that there as ester oil at least one polycarboxylic acid ester of a polycarboxylic acid with at least contains a 5- to 7-membered ring. 4. Lubricant according to one of claims 1 to 3, characterized in that that there is at least one polycarboxylic acid ester of a polycarboxylic acid as ester oil contains at least one double bond in the ring. 5. Lubricants according to one of claims 1 to 4, characterized in that that there is at least one polycarboxylic acid ester of a polycarboxylic acid as ester oil contains carboxyl groups bonded directly to ring carbon atoms. 6. Lubricant according to one of claims 1 to 5, characterized in that that there is at least one ester of trimellitic, pyromellitic and / or a Cyclnoctentetracarbonsäure, especially 1,4-Äthenocyclohexantetracar contains bonic acid. 7. Lubricant according to one of claims 1 to 6, characterized in that that there is at least one polycarboxylic acid ester with an aliphatic as ester oil contains ester residues derived from monohydric alcohol. 8. Lubricant according to claim 7, characterized in that it is as Ester oil at least one polycarboxylic acid ester with one, preferably branched chain Contains ester residues derived from C5-10 alkanol, in particular 2-ethylhexanol. 9. Lubricant according to one of claims 1 to 8, characterized that a high-pressure additive made from a sulfurized mixture is more natural as a high-pressure additive and synthetic fatty esters. 10. Lubricant according to one of claims 1 to 9, characterized in that that there is an anti-corrosion additive based on zinc complex soaps and / or - contains. 11. Lubricant according to one of claims 1 to 10, characterized in that that it, based on still total weight, 0.2 to 6, preferably 0.1 to 3 and especially 0.8 to 1.2 weight percent high pressure additive and 0.01 to 5, preferably 0.1 contains up to 2.5 and in particular 0.6 to 1.4 percent by weight of corrosion protection additive. 12. Use of a lubricant according to any one of claims 1 to 11 as a two-stroke oil, preferably in a lubricating oil / fuel mixture ratio of at least about 1 s 200.