JPS61241396A - Lubricant - Google Patents

Abstract

PURPOSE:To provide a lubricant containing a specific N<omega>-long-chain monoacyl basic amino acid and suitable for the lubrication, cutting, grinding, pressing, drawing, rust-prevention, etc., of the contacting surface of a rotating machine or an apparatus having movable part, e.g. a metal cutting machine, automobile, engine, hydraulic press, etc. CONSTITUTION:The objective lubricant contains the N<omega>-long-chain monoacyl basic amino acid having a 8-22C (un)saturated aliphatic acyl group [e.g. caprylol, lauroyl, palmitoyl, stearoyl, (hardened) beef tallow acyl, cocoyl, beheyl, etc.]. The amino acid can be produced easily by introducing a hydrophobic acyl group to an alpha,omega-basic amino acid such as lysine, ornithine, etc. EFFECT:It provides a solid lubricant having excellent smoothness, heat-resistance, oxidation-resistance and adhesivity to metal surface or a grease and liquid lubricant, etc., having high extreme-pressure property and antiseizure effect.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to N-
A lubricant containing at least one type of long-chain monoacyl basic amino acids, such a lubricant in the form of a solid lubricant, grease, liquid lubricant, etc., is used for metal cutting machines,
It can be used for lubrication, cutting, grinding, pressing, drawing, rust prevention, etc. of contact surfaces of all kinds of rotating equipment and equipment with moving parts, such as automobiles, engines, and hydraulic machines.

Conventional technology Conventional lubricants can be classified based on their appearance: solid lubricants,
It can be divided into three types: grease and liquid lubricant.

Among these, solid lubricants are suitable for applications where normal lubricants cannot be used, such as places where friction occurs at very low speeds and no lubricating oil film can be formed, at extremely low or high temperatures, or in food manufacturing machines. In addition to being used as is in equipment that dislikes odors, it is also used in a wide range of general lubricant applications, such as being mixed with thickeners and lubricating oils to make grease, and being added to liquid lubricants such as mineral oil and silicone oil. It is being As such solid lubricants, graphite, mica, talc, zinc white, sulfur, molybdenum sulfide, cadmium chloride, lead iodide, zinc stearate, and the like are known. These solid lubricants are required to have excellent smoothness, heat resistance, oxidation resistance, adhesion to metal surfaces, etc., and when blended into grease or liquid lubricants, they are also required to have excellent properties in the oil used. A material with good dispersibility is required. However, among the conventional solid lubricants mentioned above, inorganic solid lubricants such as mica, talc, and molybdenum disulfide have excellent smoothness and heat resistance, but have weak adhesion to metal surfaces. , or because of its high specific gravity, it has poor dispersibility when suspended in mineral oil or silicone oil, and has the disadvantage of being susceptible to separation during long-term storage. Furthermore, the use of cadmium chloride, lead iodide, and the like has been avoided in recent years due to the problem of environmental pollution caused by heavy metals. On the other hand, when zinc stearate, which is an organic solid lubricant, is blended into grease etc., it disperses well and produces a grease with excellent water resistance and extreme pressure properties, but on the other hand, zinc stearate promotes oxidation of the lubricating oil. For,
Such greases have the disadvantage of being susceptible to corrosion and deterioration of metals.

Problems to be Solved by the Invention The present invention improves the drawbacks of the conventional solid lubricants, greases, and liquid lubricants described above, and provides a lubricant with excellent smoothness, heat resistance, oxidation resistance, adhesion to metal surfaces, etc. The present invention aims to provide lubricants such as solid lubricants, greases with extreme pressure properties and high sintering prevention effects, and liquid lubricants.

Means for Solving the Problems While researching various derivatives of amino acids, the present inventors surprisingly found that an N'''-monoacyl basic amino acid 5 having an aliphatic acyl group having 8 to 22 carbon atoms It has a plate-like crystal structure and cleavability, and has excellent properties as a solid lubricant such as smoothness, antioxidation, and adhesion to metals due to chelate, and at the same time, it can be blended into grease and liquid lubricants. The inventors have discovered that a lubricant that overcomes the conventional drawbacks can be obtained by the above method, and have arrived at the present invention.

The N"-monoacyl basic amino acids used in the present invention can be easily obtained by introducing a hydrophobic acyl group into α,ω basic amino acids such as lysine or ornithine. After protecting the amino group at position, the known Schotten-Bauman
By acylating the amino group at the ω position in an n reaction and then removing the protecting group at the α position, the desired N''-monoacyl basic amino acid can be obtained. Alternatively, the method described in Japanese Patent Publication No. 51-2861Q It can also be obtained similarly by the method.

Examples of the basic amino acids constituting the N''-monoacyl basic amino acids used in the present invention include lysine ornithine, which may be in an optically active form or a racemic form, and as an acyl group. Carbon number 8 to 2
2 saturated or unsaturated aliphatic acyl groups are used,
Specifically, capriloil, lauroil, myristoil,
Examples include valmitoyl, stearoyl, hardened beef tallow acyl, beef tallow acyl, cocoyl, behenoyl, and the like. Furthermore, it may be a mixture of these acyl groups.

The N''-monoacyl basic amino acid obtained by the above method is a tabular powder microcrystal, and can be used as a solid lubricant as it is or by grinding it to a desired particle size. When amino acids are attached to the interface between metals that are moving repeatedly and apply friction, they significantly lower the friction coefficient of both interfaces and smooth the movement between the two metals. Solid lubricants such as graphite, mica, talc, zinc white, sulfur, molybdenum sulfide, and zinc stearate may be used in combination as appropriate.

It is also possible to use mineral oil or synthetic lubricating oil as a base oil and add 5,N3-monoacyl basic amino acid as a thickening agent to the base oil and use it as a grease. At this time, the amount added varies depending on the type of base oil, the conditions of use of the grease, etc., but is, for example, 0.1 to 100 parts by weight, particularly preferably 5 to 30 parts by weight, per 100 parts by weight of the base oil. If the amount is less than 0.1 part by weight, the effect of adding N″-monoacyl basic amino acid is small;
If it contains 100 parts by weight, the consistency will increase too much and it is not suitable as a grease.Lubricating oils that can be used as base oils include mineral oils such as baraffin-based oils, naphthenic-based oils, and aromatic-based oils, as well as sebacic acid. Diester oils such as diesters and fatty acid diesters, hydrocarbon oils such as ethylene polymerized oils and propylene polymerized oils, alkylated aromatics such as dodecylbenzene and didodecylbenzene, polyalkylene oxides such as polyoxyethylene oxide and polypropylene oxide, polyalkyl Synthetic lubricating oils such as ether, polyvinyl ether, polyalkyl ether and ester, halogenated carbon 1, urea, amine and imine, acid amide, silicone oil, etc. are included.These mineral oils and synthetic lubricating oils may be used as necessary. They can be used alone or in combination. Furthermore, metal soaps commonly used as thickeners for grease, such as lithium soap, sodium soap,
Calsulam soap, or organic bentonite, polyurea, silica gel, sodium terephthalate, etc.
It is also possible to use monoacyl basic amino acids in combination.The lubricant of the present invention may also contain various additives, such as extreme pressure agents, detergents, pour point depressants, There is no problem in adding antifoaming agents, antioxidants, viscosity index improvers, aroma improvers, colorants, fluorescent dyes, and the like.

Action N6? - Crystals of monoacyl basic amino acids are cleavable, and when crushed, they form fine plate-shaped crystals,
Demonstrates extremely high smoothing effect. In addition, Honjima has chelating power and has excellent adhesion to metal surfaces. Furthermore, Honjima has a specific gravity of approximately 1.2, which is significantly lighter than other inorganic solid lubricants, so it is less likely to settle or separate when added to lubricating oil, and is also effective in preventing oil oxidation. It has many excellent features as a solid lubricant, grease, and lubricating oil additive.

Effects of the Invention As mentioned above, the N"-monoacyl basic amino acid of the present invention has unprecedented properties as a solid lubricant, grease, and lubricating oil additive, and by using it, an excellent lubricant can be obtained. For example, when N"-monoacyl basic amino acids are used as solid lubricants, they are less likely to have chemical toxicity, metal corrosivity, adhesion to metal surfaces, and high Excellent lubricity under load can be obtained. In addition, by using solid lubricants such as graphite, mica, talc, zinc white, sulfur, and molybdenum sulfide, it is possible to improve the adhesion and metal corrosion of the back surface of these gold lx. ' can also be done. Furthermore, N'-monoacyl basic amino acids are composed of amino acids and fatty acids that constitute living organisms, are non-toxic to the human body, and are extremely safe. Therefore, it is suitable for use as a lubricant for food, pharmaceutical and cosmetic manufacturing machines, etc.

Furthermore, when N-substituted monoacyl basic amino acids are blended into greases, lubricating oils, etc., improvements in lubricity under high loads, oxidation resistance, metal corrosion resistance, etc. are observed compared to those that do not contain this amino acid.

In this way, the lubricant containing the Na-monoacyl basic amino acid, invented from scratch, solves many problems of conventional lubricants, and can be used in all types of rotating equipment and equipment with moving parts. Can be used for lubrication, cutting, polishing, pressing, drawing, rust prevention, etc. of contact surfaces.

EXAMPLES Examples of the present invention are shown below, but it goes without saying that the present invention is not limited thereto.

Example 1 A metal base provided with a circular concave portion having a diameter of 5.1+u+ and a rotating metal rod having a diameter of 5.0 w+m and having a thrust load of 1000 g applied to the upper portion thereof were brought into contact at the concave portion. Such a device (A) and a device (B) in which a small amount of Nr''-lauroyl lysine with a particle size o of 1 to 10 μm are interposed between them.
) in a room temperature atmosphere at 500 rpm+ for 10 minutes,
The situation during rotation of the two and the situation of the contact surface after rotation was compared.

In the fruiting device (A), an abnormal metallic sound was heard during the rotation test, and scratches were caused by friction on the contact surface after the rotation was completed.

On the other hand, in device (B), it was quiet even during rotation, and no scratches were observed on the contact surface after rotation, indicating that the effect of NL-lauroyl lysine as a solid lubricant was remarkable.

Cold Example 2 Based on the recipe in Table 1, hydrogenated fish oil fatty acids, lucium hydroxide, and naphthene-based mineral oil were heated to 57°C with an open flame heating iron, and heated and stirred for 4.5 hours until the temperature rose to 260°C. Warm up. Stir at that temperature for 2 hours to evaporate water, evacuate the inside of the can with carbon dioxide, pressurize to 2 atm, pressurize into a cooling tank with a cooling jacket, cool to 225°C, and further 0.
Stir for 5 hours and continue cooling to 121°C. Here, the remaining additives were added, and the mixture was further cooled to 93° C., filtered, degassed, and applied to a homogenizer to obtain calcium grease. Table 2 shows the test results for the calcium grease thus obtained.

Table-1 BCDEF Hydrogenated fish oil fatty acid 222444 Glacial acetic acid 888888 Lucium hydroxide 666666 Naphthenic mineral oil 80 80 84 78 78
82N6-sty70yl 4--4- -lysine N-lauroyl -4--4- Table 2 Prescription test Item ABCDEFNorm
a-Hoffmann 375 385
34 344 364 26 Oxidation test (51b/
in, h) AFBMA-NLGIII sliding life 645625610
558578527 (100GOrpm+, 25G”
F) Greases containing N-monoacyl basic amino acids according to the present invention (formulations A, B, D%E) were found to be superior in both oxidation resistance and lubrication life compared to comparative examples (formulations C and F). It will be done.

Example 3 2 mmol of a sample is placed in 20 ml of refined olive oil and heated at 97.8° C. while blowing air. Sampling was carried out over time, and the amount of peroxide produced was quantified based on the standard oil and fat analysis method.

As seen in Figure 1, NA-acyl lysine is recognized to have the effect of preventing the oxidation of oils and fats, and suppressing the formation of peroxide 1, which has a corrosive effect on metals. Moreover, such characteristics were remarkable for long-chain acyl lysines having 8 or more carbon atoms.

Example 4 Water/methanol mixed solvent containing 1100 pp of copper sulfate (
50 mg of N'-lauroyl lysine was added to 100 ml (1:1 weight ratio), stirred at room temperature for 1 hour, and then filtered.

The amount of copper ions remaining in the filtrate was determined by optical emission spectrometry (IC).
P) and the results compared with the case without additives are shown in Figure-
Shown in 2.

As is clear from these results, N1-lauroyl lysine has the ability to capture metal ions, and when added to grease, lubricating oil, etc., also functions as a metal deactivator.

[Brief explanation of the drawing]

Figure 1 shows the antioxidant effect of N1-lauroyl lysine on refined olive oil. The w-axis shows the heating time, and the vertical axis shows the peroxide value, that is, the number of milliequivalents of iodine released from potassium iodide by the retreated products present in 1 kg of fat and oil. N! -The metal ion trapping properties of lauroyl lysine are shown in Figure 2. The horizontal axis shows the detection wavelength, and the vertical axis shows the absorption intensity of light by copper ions.

Claims (1)

[Claims] A lubricant containing at least one type of N^ω-long-chain monoacyl basic amino acid having an aliphatic acyl group having 8 to 22 carbon atoms.