KR101973490B1 - Lubricating additives composition, methode for preparing the same and lubricant oil comprising the same - Google Patents

Abstract

Provided is a lubricant additive composition that maintains good lubricity even when small amounts of tungsten disulfide are added by including non-polar surface modified graphene oxide nanoparticles, tungsten disulfide nanoparticles, zinc dithiophosphate, molybdenum dithiomate and 1-(2,2,6-trimethylcyclohexyl)pentan-3-ol.

Description

Lubricating oil additive composition, preparation method thereof, and lubricating oil comprising same TECHNICAL FIELD

The present invention relates to a lubricating oil additive composition, a method for preparing the same, and a lubricating oil including the same. Specifically, the non-polar surface-modified graphene oxide nanoparticles, tungsten disulfide nanoparticles, zinc dithiophosphate, molybdenum dithiomate and 1- By including (2,2,6-trimethylcyclohexyl) pentan-3-ol, the present invention relates to a lubricating oil additive composition that maintains excellent lubricity even when a small amount of tungsten disulfide is added and improves dispersion stability.

In engines of automobiles and various industrial machines, friction and abrasion are continuously generated at friction sites between metals such as pistons, combustion chamber inner walls, piston rings, camshafts, and reciprocating crankshaft bearings, which are driving parts that generate friction between metals.

The engine is a key part of the machine, so it is not easy to change frequently, so to improve the life of the engine, lubricating oil is used in areas where repeated friction occurs. Recently, lubricants have been developed that include lubricant additives to compensate for the additional functions required for the operation of the engine in lubricants for lubrication only.

As one of the lubricant additives, solid lubricant additives have higher heat resistance and higher wear resistance than liquid lubricant additives. The conventional solid lubricant additives already developed and applied include polytetrafluoroethylene (PTFE) or molybdenum disulfide. And a composition using (MoS ₂ ) or the like. However, they have the disadvantage of solid phase which precipitates and aggregates and is filtered in the oil filter and the oil filter and thus are not suitable as automotive engine lubricants. In particular, in the case of lubricating oil containing molybdenum disulfide, the wear resistance is not high, and there is a possibility of causing toxic damage to the exhaust gas treating catalyst, and there is a disadvantage of changing to molybdenum oxide at a high temperature. It's urgent.

In addition, the chlorine-based paraffin-added composition has excellent extreme pressure lubrication activity and is used as an extreme pressure anti-wear agent.However, it is easily decomposed in an internal combustion engine that generates heat such as an automobile engine, causing problems such as corrosion of metal and carbonization of oil to maintain desired oil properties. There are disadvantages that are difficult to do.

Therefore, in order to replace these conventional lubricating materials, it has a low coefficient of friction and disulfide which maintains lubricity even under the harsh conditions of high temperature, high pressure and high hatching because it has excellent oxidation resistance and pressure resistance compared to graphite and molybdenum disulfide. The use of tungsten is increasing. However, since tungsten disulfide is expensive, there is an urgent need to develop a lubricant additive that can improve the lubricating function even if the amount of tungsten disulfide is reduced.

On the other hand, in the case of functional lubricating oil, the additive component added in the lubricating oil is uniformly dispersed in the lubricating oil and has excellent dispersion stability, so it is necessary to keep the additive dispersed state for a long time, and the lubricating function and other additional functions can be maintained for a long time. As a result, securing dispersion stability of the additive component in the lubricant is an important factor in the life of the lubricant.

Korean Patent No. 10-1659319 discloses a lubricating oil additive composition containing tungsten disulfide and improves dispersibility by adding a silane coupling agent, but relates to a lubricating oil additive which maintains dispersion safety for a long time in the lubricating oil additive. Is not disclosed.

Therefore, while maintaining the characteristics of wear resistance and friction resistance, which are the basic characteristics of the lubricant, there is a continuing demand for the development of a lubricant with improved dispersion stability and improved life.

Korea Patent Registration No. 10-1659319

The present invention aims to solve the problems of the prior art as described above and the technical problems that have been requested from the past.

The inventors of the present invention, after recognizing the above problems and repeating numerous experiments and studies to solve them, use tungsten disulfide and graphene oxide together, and together with 1- (2,2,6-trimethylcyclo In the case of using hexyl) pentan-3-ol, the inventors have invented and completed the present invention having an effect of extending the life of the lubricating oil, while maintaining the wear resistance and the friction resistance compared to the lubricating oil containing only tungsten disulfide.

Moreover, an object of this invention is to provide the manufacturing method of a lubricating oil composition.

Therefore, the lubricant additive composition according to the present invention for achieving the above object is an emulsion solution in which graphene oxide nanoparticles and tungsten disulfide (WS ₂ ) nanoparticles are dispersed in a base oil, Zinc dithiophosphate (ZnDTP), molybdenum dithiocarbamate (MoDTC) and 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol (1- (2,2, 6-trimethylcyclohexyl) pentan-3-ol), wherein the graphene oxide is a non-hydrophilic surface modified lubricant additive composition.

The lubricant additive composition according to the present invention may comprise an emulsion solution in an amount of 30 to 60 wt% based on the total weight of the lubricant additive composition.

The lubricant additive composition according to the present invention may include the zinc dithiophosphate in 10 to 25% by weight based on the total weight of the lubricant additive composition.

The lubricant additive composition according to the present invention may include 10 mol% to 25 wt% of the molybdenum dithiocarbamate based on the total weight of the lubricant additive composition.

The lubricant additive composition according to the present invention may comprise 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol in an amount of 1 to 10% by weight based on the total weight of the lubricant additive composition.

In addition, the emulsion solution may include a base oil of 24 to 45% by weight, 1 to 5% by weight of graphene oxide nanoparticles and tungsten disulfide 5 to 10% by weight based on the total weight of the lubricant additive composition.

In the lubricant additive composition according to the present invention, the non-hydrophilic surface-modified graphene oxide, the oxygen atom of graphene oxide is substituted with a non-hydrophilic functional group, the non-hydrophilic functional group is an alkyl group, alkenyl group (alkenyl) group), an alkynyl group, an phenyl group, an aryl group, a cycloalkyl group and a cycloalkenyl group.

In the lubricant additive composition according to the present invention, the non-hydrophilic functional group constituting the graphene oxide may be composed of 10 to 20 carbon atoms.

In addition, in the lubricating oil additive composition according to the present invention, the base oil is mineral oil, polyalphaolefin (PAO), alkylbenzene, alkylnaphthalene, polyvinyl ether, polyalkylene glycol, polycarbonate, polyol ester, ethylene alpha It may be one or more selected from the group consisting of an olefin copolymer, polybutene, aromatic ester, hindered ester, dibasic ester, paraffinic mineral oil and naphthenic mineral oil.

On the other hand, the present invention is a method for producing a lubricating oil additive composition, (a) preparing an emulsion solution in which the graphene oxide nanoparticles and tungsten disulfide nanoparticles are dispersed in a base oil, (b) 1 in the emulsion solution -(2,2,6-trimethylcyclohexyl) pentan-3-ol and uniformly mixing, and (c) zinc dithiophosphate (ZnDTP) and molybdenum dithiocarbamate in the emulsion solution. (Molybdenum dithiocarbamate, MoDTC) provides a method for producing a lubricant additive composition comprising the step of mixing.

The present invention also provides a lubricating oil comprising the lubricating oil additive composition.

As described above, the lubricant composition according to the present invention maintains the wear resistance and the friction resistance to the same level as using only tungsten disulfide, while not only reducing the lubricating oil manufacturing cost, but also excellent in the dispersion stability and the dispersion holding ratio, It is effective to keep the life longer.

1 is a photograph showing the results of the dispersion stability of the additives in the lubricant of Comparative Example 1 and Example 1.

In the following, each configuration will be described in more detail, but this is only one example, the scope of the present invention is not limited by the following.

The present invention is an emulsion solution in which graphene oxide nanoparticles and tungsten disulfide (WS ₂ ) nanoparticles are dispersed in a base oil, zinc dithiophosphate (ZnDTP), molybdenum dithiocarba Lubricant additive composition comprising Molybdenum dithiocarbamate (MoDTC) and 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol (1- (2,2,6-trimethylcyclohexyl) pentan-3-ol) To provide.

In lubricating oils, base oil is a component that substantially lubricates, and as the engine device becomes more efficient, demand for lubricating oils having additional functions in addition to lubricating action is increasing. Accordingly, as a lubricant additive for imparting additional functionality, the lubricant additive composition according to the present invention includes tungsten disulfide (WS ₂ ) and graphene oxide, and the oxygen atoms of graphene oxide are substituted with non-hydrophilic functional groups to modify the non-hydrophilic surface. It characterized in that it comprises a graphene oxide.

As a solid lubricant additive, tungsten disulfide and graphene are useful lubricant additives in that they improve friction characteristics of lubricants and impart excellent wear resistance, but tungsten disulfide is an expensive problem despite excellent lubrication and stable properties. Due to this, there is a limit to use as a lubricant additive.

In addition, graphene is excellent in physical and chemical stability, and when used in combination with tungsten disulfide can further improve abrasion resistance and friction resistance, but it is functionally excellent, but it is difficult to process graphene, thereby producing a unit price. There is a rather high disadvantage.

Therefore, the lubricating oil additive composition according to the present invention includes graphene oxide capable of maintaining a low production cost and mass production instead of graphene, and having the same wear resistance and friction resistance as that of graphene.

Graphene oxide has a hydrophilic property by the non-covalent electron pair of oxygen, in order to solve the disadvantage that it is difficult to mix with the oil component constituting most of the lubricating oil, the lubricant additive composition according to the present invention is a non-hydrophilic functional group in the oxygen atom Contains graphene oxide connected.

The non-hydrophilic functional group is an alkyl group, an alkenyl group, an alkynyl group, a phenyl group, an aryl group, a cycloalkyl group and a cycloalkenyl group It may be one or more selected from the group consisting of, the non-hydrophilic functional group is characterized in that consisting of 10 to 20 carbon atoms.

The lubricant additive composition according to the present invention comprises an emulsion solution in which tungsten disulfide nanoparticles and graphene oxide nanoparticles are dispersed in a base oil, and the emulsion solution is based on a total weight of the lubricant additive composition of 24 to 45 weight. %, 1 to 5% by weight of graphene oxide nanoparticles and tungsten disulfide may be included in 5 to 10% by weight.

The lubricant additive composition according to the present invention is an emulsion solution in which graphene oxide nanoparticles and tungsten disulfide (WS ₂ ) nanoparticles are dispersed in a base oil, zinc dithiophosphate (ZnDTP), Molybdenum dithiocarbamate (MoDTC) and 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol, wherein the emulsion solution is 30 to 60 based on the total weight of the lubricant additive composition It may be included in weight percent.

In the present invention, the base oil may be any lubricating base oil used in the art, and specifically, polyalphaolefin (PAO), alkylbenzene, polyether, polyalkylene glycol, polyol ester, ethylene alpha olefin It may be any one or more selected from the group consisting of copolymers, polybutenes, aromatic esters, hindered esters, basic esters, paraffinic mineral oils and naphthenic mineral oils, preferably mineral oil oils or polyalphaolefins. (PAO) or mixtures thereof.

The zinc dithiophosphate may be included in 10 to 25% by weight based on the total weight of the lubricant additive composition, the molybdenum dithiocarbamate may be included in 10 to 25% by weight relative to the total weight of the lubricant additive composition.

The lubricant additive composition according to the present invention includes 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol and may be included in an amount of 1 to 10% by weight based on the total weight of the lubricant additive composition. Preferably, it may be included in 1.5 to 9% by weight, most preferably, it may be included in 3 to 6% by weight.

In the lubricating oil additive composition, when the emulsion solution, zinc dithiophosphate and molybdenum dithiocarbamate are included in the content range, it has the best effect of wear resistance and friction resistance.

The lubricant additive composition according to the present invention comprises 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol, thereby dispersing graphene oxide nanoparticles and tungsten disulfide (WS ₂ ) nanoparticles. In the emulsion solution to keep the nanoparticles dispersed in the base oil, so that the life of the lubricating oil compared to the case without the addition of 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol Has a long effect.

When 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol is added in an amount less than 1% by weight based on the total weight of the lubricant additive composition, 1- (2,2,6-trimethylcyclohexyl The effect of improving the service life of lubricating oil by adding pentan-3-ol is insignificant, and when it adds in more than 10 weight%, there exists a problem of rather falling abrasion resistance.

In addition to the above components, the lubricant additive composition according to the present invention may contain, as necessary, viscosity index improvers, pour point depressants, antiwear agents, extreme pressure additives, friction modifiers, corrosion inhibitors, emulsifiers, oil separators, antifoaming agents, colorants and seal swelling agents. agnet).

On the other hand, the method for producing a lubricant additive composition according to the present invention, (a) preparing an emulsion solution in which the graphene oxide nanoparticles and tungsten disulfide nanoparticles are dispersed in a base oil, (b) to the emulsion solution 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol was added and mixed uniformly, followed by (c) zinc dithiophosphate (ZnDTP) and Mixing molybdenum dithiocarbamate (MoDTC).

Each component included in the lubricant additive composition is the same as described above.

In the step (a), the method of dispersing the nanoparticles is not particularly limited, but when the dispersibility is increased by physical stimulation by ultrasonic waves, the life of the lubricating oil is more improved.

Similarly, in the step of adding and mixing 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol to the emulsion solution which has passed through step (a), the ultrasonic wave is added to improve the physical dispersibility. Dispersion stability and dispersion maintenance ratio of the lubricating oil prepared as is maintained high.

The present invention also provides a lubricating oil comprising the lubricating oil additive composition according to the present invention.

On the other hand, the lubricating oil is engine oil, specifically passenger car engine oil, diesel engine for large vehicles, medium diesel oil, rail rail oil, marine engine oil, natural gas engine oil, 2-cycle engine oil, steam turbine oil, gas turbine Oil, combined cycle turbine oil, R & O oil, industrial gear oil, automatic gear oil, compressor oil, manual transmission oil, automatic transmission oil, slideway oil, quench oil quench oil, flush oil, hydraulic fluid, and the like.

In the case of the lubricating oil including the lubricating oil additive composition according to the present invention, the lubricating oil additive composition may be added to be 85 to 95 wt% of the total weight of the lubricating oil, and the lubricating oil additive composition may be added at 5 to 15 wt%.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the scope of the present invention is not limited thereto.

Preparation of Lubricant Additives Compositions

A lubricant additive composition was prepared as described in Table 1 below. The amount of each component is based on the weight percent.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Reference Example Emulsion solution 54 58 52 60 45 54 54 ZnDTP 20 20 20 20 20 15.5 23 MoDTC 20 20 20 20 20 15.5 23 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol 6 2 8 - 15 15 - total 100 100 100 100 100 100 100

Each compound included in the composition is as follows.

81 parts by weight of PAO (polyalphaolefin) and 6 parts by weight of graphene oxide nanoparticles modified with Dodecenyl in an emulsion solution, and 13 parts by weight of tungsten disulfide nanoparticles having a particle size of 100 nm An emulsion solution was prepared.

However, in the case of the reference example, tungsten disulfide nanoparticles having a particle size of 100 nm were mixed at 19 parts by weight without adding graphene oxide nanoparticles.

Preparation of Lubricant

Samples were prepared by mixing the lubricant additive compositions prepared according to Examples and Comparative Examples to 10 wt% of the total weight of the lubricant and 90 wt% of the engine oil.

Friction Coefficient Measurement

The coefficient of friction test conditions and the coefficient of friction of each sample are listed in Table 2 below.

SRV test (ball on disk type friction coefficient tester)
Exam conditions

Type: ball on disk
Strock: 2mm
Load: 400N
Time: 10 min
Frequency: 50 Hz
Temp: 80 ℃ Engine oil sample
Example 1
Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Reference Example Coefficient of friction 0.100 0.050
0.060 0.055 0.068 0.08 0.073 0.055

As shown in Table 2, in the case of adding 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol, the friction coefficient value is lower than that of the engine oil and the comparative examples without the additive It can be seen that.

In particular, in the case of Comparative Examples 2 and 3 in which 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol was added in an excessive amount compared to the Examples, higher friction than in Comparative Example 1 without addition thereof It can be seen that it represents a coefficient.

Wear Resistance Measurement

Wear resistance test conditions and the wear resistance test results of each sample are listed in Table 3 below.

Multi-specimen friction and wear test machine
Exam conditions
Type: ball on ball
Time: 60 min
Rpm: 1200 rpm
Temp: 75 ℃
Load: 147 N
Engine oil sample
Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Reference Example Wear scar (mm) 0.80 0.60 0.62 0.66 0.70 0.78 0.75 0.60

Referring to Table 3 above, in the case of adding 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol, since the wear scar appears small, it can be seen that the wear resistance is excellent.

In the case of Comparative Examples 2 and 3 in which 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol was added in an excessive amount compared to the examples, the wear scar was close to the engine oil without the additive. It was found that this was formed long, resulting in poor wear resistance.

Dispersion Stability Measurement

The lubricant additive compositions according to Examples and Comparative Examples were added to the engine oil, stirred at about 1000 rpm and evenly dispersed.

Over time, the color change of the lubricant according to the dispersion of graphene was visually confirmed.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Comparative Example 3 Immediately after stirring 7 7 7 6 7 7 After 15 days 7 5 6 One 6 7 After 25 days 6 3 6 One 6 6

(Scoring is based on how dark the lubricant is, 1 (transparent) to 7 (dark))

Referring to Table 4, after adding the additive composition according to the Examples and Comparative Examples to the engine oil, it was confirmed the dispersibility over time. In Comparative Example 1 in which 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol was not added, it was confirmed that the additive precipitated around 15 days.

In Examples 1 to 3, it can be seen that excellent dispersibility compared to Comparative Example 1. In Comparative Examples 2 and 3, it was confirmed that excellent dispersibility was obtained at a level similar to that of Examples. However, it can be seen that there is a problem in that the friction coefficient is high and the wear resistance is lower than that in the case where 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol is not added, even though it exhibits excellent dispersibility.

Therefore, it can be seen that Examples 1 to 3 maintain the excellent dispersibility of the additive in the lubricating oil, and together with the friction coefficient and the wear resistance.

Claims (11)

An emulsion solution in which graphene oxide nanoparticles and tungsten disulfide (WS ₂ ) nanoparticles are dispersed in a base oil;
Zinc dithiophosphate (ZnDTP);
Molybdenum dithiocarbamate (MoDTC); And
1- (2,2,6-trimethylcyclohexyl) pentan-3-ol (1- (2,2,6-trimethylcyclohexyl) pentan-1-ol);
As a lubricating oil composition comprising:
The graphene oxide is a lubricant additive composition, characterized in that the non-hydrophilic surface modified. The method of claim 1,
The emulsion solution is a lubricant additive composition, characterized in that it comprises 30 to 60% by weight relative to the total weight of the lubricant additive composition. The method of claim 1,
The zinc dithiophosphate is a lubricant additive composition comprising 10 to 25% by weight based on the total weight of the lubricant additive composition. The method of claim 1,
The molybdenum dithiocarbamate is a lubricant additive composition, characterized in that it comprises 10 to 25% by weight based on the total weight of the lubricant additive composition. The method of claim 1,
The 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol is contained in an amount of 1 to 10% by weight based on the total weight of the lubricant additive composition. The method of claim 1,
The emulsion solution is characterized in that it comprises a base oil of 24 to 45% by weight, 1 to 5% by weight of graphene oxide nanoparticles and 5 to 10% by weight of tungsten disulfide relative to the total weight of the lubricant additive composition, lubricant additive composition. The method of claim 1,
The non-hydrophilic surface-modified graphene oxide is substituted with a non-hydrophilic functional group in the oxygen atom of the graphene oxide,
The non-hydrophilic functional group is at least one selected from the group consisting of an alkyl group, an alkenyl group, an alkynyl group, a phenyl group, an aryl group, a cycloalkyl group and a cycloalkenyl group Lubricating oil additive composition. The method of claim 7, wherein
The non-hydrophilic functional group is a lubricant additive composition, characterized in that consisting of 10 to 20 carbon atoms. The method of claim 1,
The base oil is mineral oil, polyalphaolefin (PAO), alkylbenzene, alkylnaphthalene, polyvinyl ether, polyalkylene glycol, polycarbonate, polyol ester, ethylene alpha olefin copolymer, polybutene, aromatic ester, Lubricating oil additive composition, characterized in that any one or more selected from the group consisting of hindered ester, dibasic ester, paraffinic mineral oil and naphthenic mineral oil. (a) preparing an emulsion solution in which graphene oxide nanoparticles and tungsten disulfide nanoparticles are dispersed in a base oil;
(b) adding 1- (2,2,6-trimethylcyclohexyl) pentan-3-ol to the emulsion solution and mixing uniformly; And
(c) mixing zinc dithiophosphate (ZnDTP) and molybdenum dithiocarbamate (MoDTC) in the emulsion solution;
Method for producing a lubricant additive composition comprising a. A lubricating oil comprising the lubricating oil additive composition according to any one of claims 1 to 9.

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