JP3956399B2 - High performance lubricant - Google Patents

Description

[0001]
[Industrial application fields]
The present invention relates to a high performance lubricating oil.
[0002]
[Prior art]
Gear oil is used under severe conditions such as high load conditions or high speed and high load conditions of general machinery, while hydraulic fluid is mainly used in hydraulic devices such as machine tools, vehicles, ships and aircraft. Both gear oil and hydraulic fluid are produced by blending various additives based on paraffinic mineral oil.
[0003]
[Problems to be solved by the invention]
However, the conventional gear oil does not have sufficient seizure resistance to cope with the reduction in the amount of oil supply for reducing the size of the gear and reducing the cost, and the conventional hydraulic fluid has a high surface pressure condition. As a result, the development of lubricants with excellent seizure resistance and wear resistance is desired as various devices have become smaller and higher performance in recent years. ing.
[0004]
The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a novel high-performance lubricating oil that has better seizure resistance and wear resistance than existing gear oils and hydraulic fluids.
[0005]
[Means for Solving the Problems]
The present invention provides 60 to 70% by weight of paraffinic mineral oil as the base oil,
20-24 wt% of a phosphate salt compound group having a long-chain alkyl group that does not have remarkably good solubility with paraffinic mineral oil as a phosphorus extreme pressure agent;
As a surfactant for improving dispersibility and penetrability, 5 to 8% by weight of a single or mixture of a fatty acid amide-based nonionic surfactant having 8 to 18 carbon atoms is blended. This relates to high-performance lubricating oil.
[0006]
Furthermore, you may mix | blend 5 to 10weight% of calcium sulfonate as a metal deactivator.
[0007]
[Action]
When a paraffinic mineral oil is used as a base oil and a phosphate salt compound group having a long-chain alkyl group that does not have a particularly good solubility with a paraffinic mineral oil is well dispersed and mixed as a phosphorus extreme pressure agent, a general existing gear can be obtained. The seizure resistance is significantly improved compared to oil.
[0008]
However, the dispersibility of the phosphate salt compounds in the paraffinic mineral oil is poor and a practical storage stability cannot be obtained. Therefore, a nonionic surfactant is added to greatly improve the dispersibility, and the storage stability In addition to improving the seizure resistance, the seizure resistance is further improved.
[0009]
In addition, the reason for selecting a nonionic surfactant as the surfactant in particular is that the corrosiveness to the metal is not considered, and among the nonionic surfactants, those having 8 to 18 carbon atoms. If a simple substance or a mixture of fatty acid amide-based nonionic surfactants is selected, matching with other blends becomes extremely good.
[0010]
Furthermore, when a nonionic surfactant is blended, the surface tension is remarkably reduced and the permeability is greatly improved. Therefore, it is considered that the lubricating oil is difficult to penetrate due to a shape problem or a high surface pressure. It is possible to satisfactorily permeate oil having high lubricity into the sliding portion, and the wear resistance when used as a hydraulic fluid is improved.
[0011]
In addition, when calcium sulfonate is blended as a metal deactivator, corrosion resistance to zinc is particularly improved.
[0012]
That is, the blend of paraffinic mineral oil and phosphate ester exhibits excellent lubricity in a well-mixed state, but exhibits good corrosion resistance against aluminum, copper, and steel, while against zinc. Therefore, when the material of the object to be lubricated is zinc, calcium sulfonate may be blended as necessary.
[0013]
【Example】
Hereinafter, the present invention will be described in detail with reference to examples.
[0014]
Phosphoric acid esters contained in the group of phosphate salt compounds having long-chain alkyl groups that do not have outstanding solubility as paraffinic mineral oil as a phosphorus extreme pressure agent in paraffinic mineral oil (64% by weight) as a base oil (22 wt%), polyoxyethylene alkylamide (8 wt%) which is a nonionic surfactant as a surfactant for improving dispersibility and permeability, and calcium sulfonate (8 wt%) as a metal deactivator ( 6% by weight) is dispersed and blended well to obtain a high-performance lubricating oil.
[0015]
Regarding the seizure resistance of the high-performance lubricating oil thus obtained, a combination of a general existing gear oil and a paraffinic mineral oil (75% by weight) and a phosphate ester (25% by weight) When compared with the case where it was used, the Falex test was evaluated as a comparison object. When the Falex test was performed using a general existing gear oil, the seizure generation load was 4000 N, whereas paraffinic mineral oil (75 Weight%) and phosphate ester (25% by weight) using a blending test, the seizure generation load was 9000 N, and further, the high performance lubricating oil in this example was used to perform the fax test. A good result was obtained that the seizure generation load in this case was 11000 N.
[0016]
In other words, simply blending a phosphate ester with a paraffinic mineral oil provides excellent lubricity, and the seizure resistance is significantly improved compared to general existing gear oils. When polyoxyethylene alkyl amide is blended as an activator, the dispersibility (solubility) of the phosphate ester in the paraffinic mineral oil is improved, whereby the seizure resistance (lubricity) is further improved.
[0017]
In this example, the phosphoric ester is mixed as a phosphorus extreme pressure agent at a blending ratio of 22% by weight. However, in the Falex test described above, the seizure generation load is 11000 N. The blending ratio at which such excellent seizure resistance was effectively exhibited was 20 to 24% by weight.
[0018]
Also, the polyoxyethylene alkylamide, which is a nonionic surfactant, is blended in the high-performance lubricating oil of this example not only for the purpose of improving seizure resistance, but also for storage stability. The purpose of improvement is also included.
[0019]
That is, the blend of paraffinic mineral oil (75% by weight) and phosphate ester (25% by weight) exhibits excellent lubricity in a well dispersed and mixed state, but for the purpose of evaluating its storage stability, When the time until it is allowed to stand and separate in a -5 ° C constant temperature bath is measured, the blend of paraffinic mineral oil (75% by weight) and phosphate ester (25% by weight) is separated in about 70 hours. It was confirmed.
[0020]
Therefore, if the paraffinic mineral oil and the phosphate ester are simply blended, separation occurs in a short period of time, and there is a possibility that the blending effect of the phosphate ester cannot be expected when the actual machine is used, resulting in trouble. .
[0021]
On the other hand, in the high performance lubricating oil of this example, the dispersibility can be remarkably improved by blending polyoxyethylene alkylamide, which is a nonionic surfactant, and in fact, in the same manner as described above, −5 When the time until it was allowed to stand and separated in a constant temperature bath at 0 ° C. was measured, a good result that it was not separated for 2000 hours or more was confirmed.
[0022]
In this example, polyoxyethylene alkylamide, which is a nonionic surfactant, is blended at a blending ratio of 8% by weight, but the polyoxyethylene alkylamide is blended at a blending ratio of less than 5% by weight. In this case, since improvement in good separability was not confirmed, it is desirable that the blending ratio is at least 5% by weight. Conversely, when the blending ratio exceeds 10% by weight, The most effective of polyoxyethylene alkylamide, a nonionic surfactant, because the phosphate ester compounded as a pressure agent is stably dispersed in the oil and inhibits the compounding effect of the phosphorus-based extreme pressure agent A typical blending ratio is considered to be 5 to 8% by weight.
[0023]
In addition, the reason for selecting a nonionic surfactant as the surfactant in particular is that the corrosiveness to the metal is not considered, and among the nonionic surfactants, those having 8 to 18 carbon atoms. If a single unit or a mixture of fatty acid amide-based nonionic surfactants is selected, matching with other compounds will be extremely good, so in this example, polyoxyethylene alkylamide is selected as an example. is there.
[0024]
Furthermore, when polyoxyethylene alkylamide, which is a nonionic surfactant, is blended, the surface tension is significantly reduced and the permeability is greatly improved. It is possible to allow oil with high lubricity to penetrate well even for sliding parts that were thought to be difficult for oil to penetrate due to high surface pressure, etc. Wear resistance is also improved.
[0025]
In fact, in the SRV test, which is a reciprocating test using the high-performance lubricating oil in this example, it was confirmed that the wear resistance was superior to that of a general existing hydraulic fluid.
[0026]
The addition of calcium sulfonate as a metal deactivator in the high-performance lubricating oil of the present example is aimed at improving the corrosion resistance particularly against zinc.
[0027]
That is, the blend of paraffinic mineral oil (75% by weight) and phosphate ester (25% by weight) exhibits excellent lubricity in a well dispersed state, but for the purpose of evaluating the corrosiveness to metals, When the immersion test of the metal to be evaluated (aluminum, copper, zinc, steel) was carried out at an oil temperature of about 100 ° C. for 600 hours and the change in the weight of the metal to be evaluated was measured after the test, paraffinic mineral oil (75% by weight) And a phosphate ester (25% by weight) formulation was found to exhibit good corrosion resistance to aluminum, copper, and steel while exhibiting corrosivity to zinc.
[0028]
This is due to the fact that the phosphate ester is corrosive to zinc, but in the high-performance lubricating oil of this example, by blending calcium sulfonate as a metal deactivator, The corrosion resistance against zinc can be greatly improved without reducing the good corrosion resistance against aluminum, copper and steel. In fact, when the immersion test is performed in the same manner as described above, the corrosion amount of zinc after the test is about It was confirmed that it was reduced to less than half.
[0029]
In addition, in this Example, although the example which mix | blended calcium sulfonate with the compounding ratio of 6 weight% as a metal deactivator is demonstrated, in the immersion test mentioned above, the corrosion amount of the zinc after a test is shown. The blending ratio at which excellent corrosion resistance, which is reduced to about half or less, was effectively exhibited was 5 to 10% by weight.
[0030]
In addition, when the above-described immersion test was performed, the property change (total acid value) of the high-performance lubricating oil of this example was measured to evaluate the thermal stability. The amount was very small (substantially no change), and it was confirmed that it has good thermal stability even after long-term use.
[0031]
The high-performance lubricating oil of the present invention is not limited to the above-described examples, and the blending ratio of each composition constituting the high-performance lubricating oil depends on the viscosity grade of the paraffinic mineral oil used as the base oil. Considering the solubility of each compound, etc., there may be some changes within a predetermined range, and if the material to be lubricated is aluminum other than zinc, copper, steel, etc., calcium is necessarily used as a metal deactivator. Of course, it is not necessary to add a sulfonate, and various modifications can be made without departing from the scope of the present invention.
[0032]
【The invention's effect】
The high-performance lubricating oil of the present invention exhibits superior seizure resistance and wear resistance compared to general existing gear oils and hydraulic fluids, and when used as gear oil, conventional lubrication is difficult. This makes it possible to reduce the size of gears and reduce the amount of oil supplied to reduce costs, which could not be realized because of this. Since it can be used under pressure conditions, it is possible to cope with recent downsizing and higher performance of various devices.

Claims (2)

60-70% by weight of paraffinic mineral oil as the base oil,
20-24 wt% of a phosphate salt compound group having a long-chain alkyl group that does not have remarkably good solubility as paraffinic mineral oil as a phosphorus extreme pressure agent;
As a surfactant for improving dispersibility and penetrability, 5 to 8% by weight of a simple substance or a mixture of a fatty acid amide type nonionic surfactant having 8 to 18 carbon atoms is blended. High performance lubricant.   The high-performance lubricating oil according to claim 1, wherein 5 to 10% by weight of calcium sulfonate is blended as a metal deactivator.