KR20240028242A - grease composition with ultra low noise, manufacturing method thereof and electrical and electronic appliances comprising the same - Google Patents

Abstract

The present invention relates to a grease composition with improved wear resistance and ultra-low noise effect while maintaining lubricating adhesion, a manufacturing method thereof, and electrical and electronic products using the same.
The grease composition according to an embodiment of the present invention includes 60 to 85% by weight of ester oil-based base oil; 10 to 25% by weight of lithium-based thickener; Additive 3-15% by weight; and 0.05 to 0.1% by weight of [reduced graphene oxide (MrGO) functionalized with a metal oxide including magnetite (Fe ₃ O ₄ )].
The method for producing a grease composition according to an embodiment of the present invention is an ultra-low noise grease containing ester oil-based base oil, lithium-based thickener, additives, and graphene oxide (MrGO) containing modified magnetite (Fe ₃ O ₄ ). In the composition manufacturing method, the reduced graphene oxide (MrGO) functionalized with a metal oxide including magnetite is prepared by adding ferrous chloride tetrahydrate (FeCl ₂ 4H ₂ O) or ferric chloride hexahydrate (FeCl) to graphene oxide (GO). mixing ₃ ·6H ₂ O) (S1 step); Obtaining [graphene oxide (GO) containing magnetite (Fe ₃ O ₄ )] by reacting ammonium hydroxide under nitrogen gas (N2) in step S1 (step S2); Washing [graphene oxide (GO) containing magnetite (Fe ₃ O ₄ )] obtained in step S2 with distilled water (step S3); Modified by reducing graphene oxide (GO) containing magnetite (Fe ₃ O ₄ ) with hydrazine monohydrate [reduced graphene oxide (MrGO) functionalized with metal oxide containing magnetite (Fe ₃ O ₄ ) ] obtaining (step S4); A manufacturing method including the step (S5 step) of mixing the above [reduced graphene oxide (MrGO) functionalized with a metal oxide containing reduced magnetite (Fe ₃ O ₄ )] using EG or CTAC as a dispersant. do.
It includes electrical and electronic products containing the grease composition according to an embodiment of the present invention.

Description

Grease composition with ultra low noise, manufacturing method thereof and electrical and electronic appliances comprising the same}

The present invention relates to ultra-low noise grease and its manufacturing method, and to electrical and electronic products using the same. More specifically, the present invention includes ester oil as a base oil, a lithium thickener, additives, and [graphene oxide functionalized with a metal oxide including magnetite]. The present invention relates to a grease composition with improved wear resistance and ultra-low noise effect while maintaining lubricating adhesion, a manufacturing method thereof, and electrical and electronic products using the same.

In general, low-noise small motors are essential in the precision industry, automobile, aerospace industry, and IT industry, but in industries where NVH (Noise, Vibration, Hardness) logic operates, such as the acoustic precision industry or automobile parts, higher performance than low noise is required. Ultra-low noise characteristics are required.

In particular, among IT-related industries, the sound manufacturing industry must use ultra-low noise motors in specific bands rather than general low noise, and in the aerospace industry, ultra-low noise motors are essential for precision devices for parts manufacturing. Accordingly, as a result of using domestic low-noise grease, none of them satisfied the requirements, and therefore all ultra-low noise grease is imported from Japan.

Meanwhile, U.S. Patent Nos. 5,116,522 and 5,108,635 related to low-noise grease used PMA (Poly Metha-Acrylate) or a lithium-based thickener in the base oil to reduce noise, but these patent documents also showed results that fell far short of ultra-low noise. It has been shown that there is no wear resistance.

In addition, Republic of Korea Patent No. 10-513625 discloses a technology to create an environment that increases usability at various temperatures, but it does not have a significant effect on noise reduction, and Republic of Korea Patent No. 10-1856251, which was developed to make up for these shortcomings, There was an effect of reducing car operating noise (2.9~8.94% reduction effect), but it did not show the effect of ultra-low noise at all. In addition, Republic of Korea Patent No. 10-1464463 is a patent related to grease for sunroof motors, and is aimed at preventing deterioration and improving wear resistance of the product, such as maintaining long-term wear resistance and extreme pressure resistance at low noise, so there is no ultra-low noise effect.

U.S. Patent No. 5,116,522 (Publication date: May 26, 1992) U.S. Patent No. 5,108,635 (Publication date: April 28, 1992) Republic of Korea Patent No. 10-513625 (Publication date: 2005. 09. 09.) Republic of Korea Patent No. 10-1856251 (Publication date: 2018. 05. 09.)

Therefore, the present invention is based on the task of providing a grease composition that exhibits ultra-low noise effect as well as low noise effect at high temperature, a method of manufacturing the same, and electrical and electronic products using the same.

In addition, the present invention is based on the problem of providing a grease composition and a manufacturing method thereof that simultaneously achieve low noise and ultra-low noise effects while improving wear resistance without deteriorating at high temperatures, and electrical and electronic products using the same.

The object of the present invention described above is 60 to 85% by weight of ester oil-based base oil; 10 to 25% by weight of lithium-based thickener; Additive 3-15% by weight; This is achieved by providing a grease composition for ultra-low noise containing 0.05 to 0.1% by weight of [reduced graphene oxide (MrGO) functionalized with a metal oxide including magnetite (Fe ₃ O ₄ )].

According to a preferred feature of the present invention, the [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] is the [graphene functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )]. Pin reduced oxide (MrGO)] Contains 5 to 15 parts by weight of magnetite (Fe ₃ O ₄ ) per 100 parts by weight.

According to a preferred feature of the present invention, the ester oil system includes dibutyl sebacate, di-2-ethylhexyl sebacate, dioctyl adipate, diisodecyl adipate, ditridecyl adipate, ditridecyl tallate, Methyl acetyl cinolate, trioctyl trimeritate, tridecyl trimeritate, tetraoctyl pyromeritate, trimethylolpropane caprilate, trimethylolpropane veralgonate, pentaerythritol-2-ethylhexanoate, pentaerythritol It includes one or more ester oils selected from beralgonate, carbonic acid ester oil, monoalkyldiphenyl ether, dialkyldiphenyl ether, and polyalkyldiphenyl ether.

According to a preferred feature of the present invention, the additive further includes one or more additives selected from the group consisting of extreme pressure additives, antioxidants, corrosion inhibitors, rust inhibitors, metal deactivators, and viscosity index improvers.

In addition, the object of the present invention described above is to manufacture an ultra-low noise grease composition containing graphene oxide (MrGO) functionalized with an ester oil-based base oil, a lithium-based thickener, additives, and a metal oxide including magnetite (Fe ₃ O ₄ ). In the method, the graphene oxide functionalized with a metal oxide including magnetite is prepared by adding ferrous chloride tetrahydrate (FeCl ₂ ·4H ₂ O) or ferric chloride hexahydrate (FeCl ₃ ·6H) to graphene oxide (GO). ₂ O) mixing step (S1 step); Obtaining [graphene oxide (GO) containing magnetite (Fe ₃ O ₄ )] by reacting ammonium hydroxide under nitrogen gas (N ₂ ) in the S1 step (S2 step); Washing [graphene oxide (GO) containing magnetite (Fe ₃ O ₄ )] obtained in step S2 with distilled water (step S3); Reducing graphene oxide containing magnetite (Fe ₃ O ₄ ) with hydrazine monohydrate to obtain [reduced graphene oxide (MrGO) functionalized with metal oxide containing magnetite (Fe ₃ O ₄ )] (step S4) ); This is achieved by providing a manufacturing method comprising the step of mixing the [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] using EG or CTAC as a dispersant (step S5). .

According to a preferred feature of the present invention, the modified [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] is functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ ) and reduced. Graphene oxide (MrGO)] Contains 5 to 15 parts by weight of magnetite (Fe ₃ O ₄ ) per 100 parts by weight.

In addition, the object of the present invention described above is achieved by providing an ultra-low noise electrical and electronic product containing the above grease composition.

The grease composition according to an embodiment of the present invention and the electrical and electronic products according to the manufacturing method thereof exhibit both low noise and ultra-low noise effects, and have the advantage of improved wear resistance without deterioration even at high temperatures.

Below, preferred embodiments of the present invention will be described in detail. However, this is intended to provide a detailed description so that a person skilled in the art can easily carry out the invention, and this does not mean that the technical idea and scope of the present invention are limited.

In addition, in the following, the grease composition is explained based on its use as a lubricant in motors, etc., but it is obvious that it can be applied to other industrial fields as well.

In the present invention, ultra-low noise effect means an Anderon value of 0.8 or less in the M band 300 to 1800 Hz, and low noise means an Anderon value of 1.2 or less in the M band 300 to 1800 Hz.

Anderon is a value that refers to the angular derivative of radial displacement, invented in the United States in the 1940s, and is a unit that represents the amount of vibration and the level of noise. It is possible to comprehensively evaluate the final rotation state in order to inspect the bearing by actually rotating it in the finished product state using the Anderon Meter. The inner ring is mounted on a spindle and rotated at 1800 r/min to preload the stationary outer ring. In addition, a high-speed pickup is brought into contact with the outer ring, and the mechanical vibration transmitted to the outer ring is extracted and evaluated as an electrical signal. By rotating the inner ring with a high-precision spindle to detect connection vibration from the outer ring, it is possible to exclude external influences and detect weak vibration. The detected vibrations are L (Low band), M (Medium band), and H ( High band) Divide into three and check and evaluate vibration or noise at each frequency.

The grease composition according to an embodiment of the present invention includes 60 to 85% by weight of ester oil-based base oil; 10 to 25% by weight of lithium-based thickener; Additive 3-15% by weight; and 0.05 to 0.1% by weight of [reduced graphene oxide (MrGO) functionalized with a metal oxide including magnetite (Fe ₃ O ₄ )].

The ester oil system includes dibutyl sebacate, di-2-ethylhexyl sebacate, dioctyl adipate, diisodecyl adipate, ditridecyl adipate, ditridecyl tallate, methyl acetyl cinolate, tri Octyl trimeritate, tridecyl trimeritate, tetraoctyl pyromeritate, trimethylolpropane caprilate, trimethylolpropane veralgonate, pentaerythritol-2-ethylhexanoate, pentaerythritol veralgonate, carbonate ester yumono It may be one or more ester oils selected from alkyldiphenyl ether, dialkyldiphenyl ether, and polyalkyldiphenyl ether.

The grease composition uses ester oil instead of synthetic hydrocarbon oil as a base oil and uses a lithium-based thickener as a thickener, thereby achieving low noise.

The lithium-based thickener preferred for the present invention can be represented by the following formula (1).

Formula 1

(R ₁₁ -COOLi)n

In Formula 1, R ₁₁ preferably represents an aliphatic hydrocarbon group having 6 to 20 carbon atoms, and n represents the integer of the fatty acid lithium soap. At this time, if the number of carbon atoms is less than 6, the thickening properties of the grease are poor, and if the number of carbon atoms is more than 20, the heat resistance deteriorates.

The lithium-based thickener is obtained by reacting a lithium hydroxide compound and a fatty acid compound. At this time, in order to leave no reactive fatty acid groups, it is preferable to mix lithium hydroxide and the fatty acid groups of the fatty acid compound so that the fatty acid groups are approximately equivalent. Additionally, the lithium hydroxide compound and the fatty acid compound may be reacted in the base oil, or a previously synthesized fatty acid lithium soap machine thickener may be mixed with the base oil. However, the preferred manufacturing method is the former method because it is easy to maintain the stability of the grease.

The present invention may further include one or more additives selected from the group consisting of extreme pressure additives, antioxidants, corrosion inhibitors, rust inhibitors, metal deactivators, and viscosity index improvers.

By using a known extreme pressure agent together as an extreme pressure additive, load resistance and extreme pressure properties can be improved. For example, the following compounds can be used. Examples of organic metals include organic molybdenum compounds such as molybdenum dithiocarbamate, molybdenum dithiophosphate, organic zinc compounds such as zinc dithiocarbamate, zinc dithiophosphate, and zinc phenate, antimony dithiocarbamate, and dithiocarbamate. Organic antimony compounds such as antimony pentaphosphate, organic selenium compounds such as selenium dithiocarbamate, organic bismuth compounds such as bismuth naphthenate and bismuth dithiocarbamate, and organic iron compounds such as iron dithiocarbamate and iron octylate. , organocopper compounds such as copper dithiocarbamate and copper naphthenate, organotin compounds such as tin maleate and dibutyltin sulfide, or organosulfonates, phenates, phosphenates, and gold of alkali metals and alkaline earth metals. Organometallic compounds such as , silver, titanium, and cadmium can also be used if necessary. As the sulfur-based compound, sulfide or polysulfide compounds such as dibenzyl disulfide, sulfurized oils and fats, ashless carbamine acid compounds, thiourea-based compounds, or thiocarbonates can be used. As the phosphoric acid-based extreme pressure agent, phosphoric acid esters such as trioctyl phosphate and tricredyl phosphate, and phosphoric acid ester-based compounds such as acidic phosphoric acid esters, phosphorous acid esters, and acidic phosphite esters can be used. Additionally, other halogen-based extreme pressure agents such as chlorinated paraffin, or solid lubricants such as molybdenum disulfide, tungsten disulfide, graphite, PTFE, antimony sulfide, and boron compounds such as boron nitride can be used. Among these extreme pressure agents, dithiocarbamic acid-based compounds and dithiophosphoric acid-based compounds can be preferably used.

As an antioxidant, it can be appropriately selected and used from anti-aging agents, ozone deterioration inhibitors, and antioxidants added to rubber, plastics, lubricants, etc. For example, the following compounds can be used. That is, phenyl-1-naphthylamine, phenyl-2-naphthylamine, diphenyl-p-phenylenediamine, dipyridylamine, phenothiazine, N-methylphenothiazine, N-ethylphenothiazine, 3,7-dioctylphenothiazine, p,p'-dioctyldiphenylamine, N,N'-diisopropyl-p-phenylenediamine, N,N'-di-sec-butyl-p-phenylenediamine Amine-based compounds such as phenol-based compounds such as 2,6-di-tert-dibutylphenol, etc. can be used.

As corrosion inhibitors, alkali metals such as ammonium salts of barium, zinc, calcium, and magnesium, organic sulfonic acid salts of alkaline earth metals, organic carbonates, phenates, alkyl phosphonates, or alkenyl succinic acid esters, etc. Kenyl succinic acid derivatives, partial esters of polyhydric alcohols such as sorbitan monooleate, hydroxy fatty acids such as oleoyl zalcosine, mercapto fatty acids such as 1-mercapto stearic acid, or their metal salts, higher fatty acids such as stearic acid, isostearyl. Higher alcohols such as alcohol, esters of higher alcohols and higher fatty acids, thiazoles such as 2,5-dimercapto-1,3,4-thiadiazole, 2-mercaptothiadiazole, 2-(decyldithio)- Imidazole-based compounds such as benzoimidazazole and benzoimidazole, disulfide-based compounds such as 2,5-bis(dodecyldithio)benzoimidazole, or phosphoric acid esters such as trisnonylphenylphosphite. , thiocarboxylic acid ester-based compounds such as dilauryl thiopropionate, etc. can be used. Additionally, nitrite and the like can also be used.

Meanwhile, various additives such as rust inhibitors, metal deactivators, and viscosity index improvers may be mixed and used as needed, and known additives may be used.

In the present invention, the [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] is the [graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )]. ] Contains 5 to 15 parts by weight of magnetite (Fe ₃ O ₄ ) per 100 parts by weight.

In the present invention, when abbreviated as [reduced graphene oxide (MrGO) functionalized with metal oxide], it means [reduced graphene oxide (MrGO) functionalized with metal oxide including magnetite (Fe ₃ O ₄ )]. .

In addition, the method for manufacturing an ultra-low noise grease composition according to an embodiment of the present invention is an ultra-low noise grease composition containing an ester oil-based base oil, a lithium-based thickener, an additive, and [reduced graphene oxide (MrGO) functionalized with a metal oxide]. In the manufacturing method, [reduced graphene oxide functionalized with metal oxide] is prepared by adding ferrous chloride tetrahydrate (FeCl ₂ ·4H ₂ O) or ferric chloride hexahydrate (FeCl ₃ ·6H ₂ O) to graphene oxide (GO). mixing (step S1); Obtaining [graphene oxide (GO) containing ironstone (Fe ₃ O ₄ )] by reacting ammonium hydroxide under nitrogen gas (N2) in the S1 step (S2 step); Washing [graphene oxide (GO) containing magnetite (Fe ₃ O ₄ )] obtained in step S2 with distilled water (step S3); By reducing [graphene oxide (GO) containing magnetite (Fe ₃ O ₄ )] with hydrazine monohydrate, [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] ] obtaining (step S4); It includes the step of mixing EG or CTAC as a dispersant into the [reduced graphene oxide (rGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] (step S5).

Meanwhile, graphene oxide (GO), although its structure is not clearly defined, is an oxide form of graphene. Graphene has carbon atoms arranged in a honeycomb shape with sp ² bonds, making one atom It is a conductive material with a layer thickness. Because of the strong π-π bond between each layer of graphene, it is not easy to extract the graphene layer, so graphite is made into oxidized oxide (graphene oxide: GO) and then reduced to reduced GO (rGO). It is a way to transform.

The [reduced graphene oxide functionalized with a metal oxide containing magnetite (Fe3O4)] is a mixture of magnetite (Fe ₃ O ₄ ) in 100 parts by weight of the [reduced graphene oxide functionalized with a metal oxide containing magnetite (Fe3O4)]. A metal compound containing 5 to 15 parts by weight is provided, where FeCl _2· 4H ₂ O and FeC _l2· 6H ₂ O are used as magnetite, and graphene oxide is reacted using NH ₄ OH under N ₂ and then dissolved in distilled water. When washed with , graphene oxide containing magnetite is produced.

The [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] is reduced to hydrazine monohydrate with a reducing agent and then dried to provide the final modified reduced graphene oxide with ultra-low noise. In order to express its function, it undergoes a post-treatment process for constant dispersion in low-noise grease. The post-treatment process uses a solution (99.9%) of Ethylene glycol (EG) or Cetrimonium chloride (CTAC) in modified reduced graphene oxide. By mixing at room temperature for about 5 hours, the final graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe3O4) is produced.

An ultra-low-noise electrical and electronic product according to an embodiment of the present invention includes the ester oil-based base oil, lithium-based thickener, additives, and modified [reduced graphene oxide (MrGO) functionalized with metal oxide]. Contains a grease composition. The electrical and electronic products include automobiles, aerospace industry parts, IT-related products, home appliances, office automation equipment, audio equipment, mobile devices, display devices, etc.

Examples 1 to 5 and Comparative Examples 1 to 6

Base oil, lithium-based thickener, [reduced graphene oxide functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] and additives as shown in the following [Table 1] (Example) and [Table 2] (Comparative Example) A grease composition with ultra-low noise [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] was prepared by mixing the composition.

At this time, additives include antioxidants, corrosion inhibitors, extreme pressure agents, anti-wear agents, and adhesion improvers. In the case of lithium-based thickener, it can be obtained by reacting lithium hydroxide compound and fatty acid compound. In the case of [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )], graphene oxide containing magnetite is reduced with hydrazine monohydrate, followed by post-treatment reaction with EG or CTAC. After ensuring dispersion stability, it was mixed with grease to produce an ultra-low noise modified graphene oxide composite grease.

Examples 1 to 5 Example Classification (weight%) One 2 3 4 5 base oil 78.85 75.65 78.84 75.64 78.8 Lithium thickener 15.3 18.5 15.3 18.5 15.3 additive 5.8 5.8 5.8 5.8 5.8 Reduced graphene oxide functionalized with metal oxide containing magnetite (Fe ₃ O ₄ )
0.05
0.05
0.06
0.06
0.1

Comparative Examples 1 to 6 Comparative example Classification (weight%) One 2 3 4 5 6 base oil 78.86 75.7 75.65 75.64 78.79 Lithium thickener 15.3 18.5 18.5 18.5 15.3 additive 5.8 5.8 5.85 5.86 5.8 Reduced graphene oxide functionalized with metal oxide containing magnetite (Fe ₃ O ₄ )
0.04
0
0
0
0.11
0

In [Table 2] above, number 6 is a commercially purchased Japanese low-noise grease, but the specific composition ratio is not known.

Test example

The noise reduction effect of the modified graphene oxide composite grease for ultra-low noise was measured using Anderon meter test equipment in accordance with ISO 15242. Here, L band means 50~300Hz, M band means 300~1,800Hz, and H band means 1,800~10,000Hz.

At this time, the test conditions are as follows.

Axial load: 50N, sample bearing: deep groove ball bearing 608, rotation speed: 1800 rpm, number of samples: 10 each Test data: 100 each. The Anderon meter measurement results of the noise reduction effect are shown in [Table 3]. At this time, regardless of the noise of the grease, the noise generated from the bearing itself could be excluded from the measurement results, because this is not related to the noise characteristics of the grease but is related to the precision of the bearing. In other words, the noise generated from the bearing itself was expressed as Andern values in the L band, while the noise from the grease was mainly expressed as Andern values in the M and H bands. Therefore, the L band value is unrelated to grease noise, but can be important data for precision inspection of bearings.

As can be seen in [Table 3], in the case of the ultra-low noise grease of Examples 1 to 5 of the present invention containing [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] , it can be seen that the result of the M band, which shows the noise reduction characteristic value of the grease, is significantly lower than that of Comparative Examples 1 to 6. This is due to the wear resistance and significantly low coefficient of friction of the grease composition containing [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe3O4)] of the present invention, which sufficiently satisfies the ultra-low noise result. Able to know.

The reason why the ultra-low noise grease composition containing [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe3O4)] of the present invention has excellent wear resistance is that [metal containing magnetite (Fe3O4)] has excellent wear resistance. This is because reduced graphene oxide (MrGO) functionalized with oxide is evenly distributed in the grease composition, reducing vibration at the friction interface and simultaneously reducing wear.

In particular, Examples 1 to 4 absolutely show an ultra-low noise effect compared to Comparative Examples 1 to 6, and even compared to Comparative Example 6 (Japanese-made, ultra-low noise grease), the grease's wear resistance and ultra-low noise effect are significantly improved. It can be seen that is significantly superior.

In addition, Examples 1 to 5 of the present invention have wear resistance in terms of Anderon values and sufficiently satisfy the target value of ultra-low noise (0.8 or less in the M band), and are superior to Japanese grease (Comparative Example 6). By showing the results, it can be seen that the function of reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ ) is being expressed.

On the other hand, when the content of [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] is less than 0.05% by weight (Comparative Example 1) or more than 0.1% by weight (Comparative Example 5) ) It can be seen that the effects of wear resistance and ultra-low noise are reduced compared to Examples 1 to 5, and the anderone level is also slightly increased. This is when reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite ( _{Fe 3 O 4} ) is _less than 0.05% by weight (Comparative Example 1). This is because reduced graphene oxide (MrGO) is insufficient compared to the entire grease composition, increasing friction, and reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ ) exceeds 0.1% by weight. In the case (Comparative Example 5), mutual aggregation occurs due to reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ ), resulting in metal oxide containing magnetite (Fe ₃ O ₄ ). The size of the functionalized reduced graphene oxide (MrGO) increases, which is believed to reduce wear resistance and cause noise. In other words, when reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ ) exceeds 0.1% by weight (Comparative Example 5), wear resistance decreases and the noise generation effect is greater than the noise reduction effect. It is judged that the larger size resulted in the failure to meet the goal of ultra-low noise.

Therefore, it can be said that an optimized capacity of the grease used is required to express the functionality of graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ ).

Test Examples 1 to 5 (Examples 1 to 5) Example One 2 3 4 5 L babd 4.45 4.53 4.23 4.55 4.81 M band 0.73 0.72 0.70 0.76 0.82 H band 0.81 0.85 0.79 0.83 0.88

Test Examples 1 to 6 (Comparative Examples 1 to 6) Comparative example One 2 3 4 5 6 L band 5.80 6.85 6.49 6.59 5.45 4.75 M band 1.56 2.17 2.08 2.36 1.21 0.80 H band 1.75 2.75 2.03 2.14 1.35 0.82

In the above, the present invention has been described with reference to one embodiment, but those skilled in the art will understand that various modifications and other equivalent embodiments are possible therefrom.

Claims (7)

60 to 85% by weight of ester oil-based base oil;
10 to 25% by weight of lithium-based thickener;
Additive 3-15% by weight; and
[Reduced graphene oxide (MrGO) functionalized with metal oxide containing magnetite (Fe ₃ O ₄ )] 0.05 to 0.1% by weight;
A grease composition for ultra-low noise containing. In claim 1,
The [reduced graphene oxide (MrGO) functionalized with a metal oxide including magnetite (Fe ₃ O ₄ )] is composed of magnetite (Fe ₃ ) relative to 100 parts by weight of the [reduced graphene oxide (MrGO) functionalized with metal oxide]. A grease composition for ultra-low noise, characterized in that it contains 5 to 15 parts by weight of O ₄ ). In claim 1,
The ester oil system includes dibutyl sebacate, di-2-ethylhexyl sebacate, dioctyl adipate, diisodecyl adipate, ditridecyl adipate, ditridecyl tallate, methyl acetyl cinolate, Trioctyl trimeritate, tridecyl trimeritate, tetraoctyl pyromeritate, trimethylolpropane caprilate, trimethylolpropane veralgonate, pentaerythritol-2-ethylhexanoate, pentaerythritol veralgonate, carbonate ester oil A grease composition for ultra-low noise, characterized in that it contains at least one type of ester oil selected from monoalkyldiphenyl ether, dialkyldiphenyl ether, and polyalkyldiphenyl ether. In claim 1,
The additive is a grease composition for ultra-low noise, characterized in that it further comprises one or more additives selected from the group consisting of extreme pressure additives, antioxidants, corrosion inhibitors, rust inhibitors, metal deactivators, and viscosity index improvers. A method for manufacturing an ultra-low noise grease composition containing an ester oil-based base oil, a lithium-based thickener, additives, and [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] Because,
The [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )],
Mixing graphene oxide (GO) with ferrous chloride tetrahydrate (FeCl ₂ ·4H ₂ O) or ferric chloride hexahydrate (FeCl ₃ ·6H ₂ O) (step S1);
Obtaining [graphene oxide (GO) containing magnetite (Fe ₃ O ₄ )] by reacting ammonium hydroxide (NH ₄ OH) under nitrogen gas (N ₂ ) in the S1 step (S2 step);
Washing [graphene oxide (GO) containing magnetite (Fe ₃ O ₄ )] obtained in step S2 with distilled water (step S3);
[Reduced graphene oxide (MrGO) functionalized with metal oxide containing magnetite (Fe ₃ O ₄ ) modified by reducing [graphene oxide (GO) containing magnetite (Fe ₃ O ₄ )] with hydrazine monohydrate ] obtaining (step S4);
Mixing the [reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] using EG (Ethylene glycol) or CTAC (Cetrimonium chloride) as a dispersant (step S5);
A method for producing an ultra-low noise grease composition comprising: In claim 5,
The [Reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] is the [Reduced graphene oxide (MrGO) functionalized with a metal oxide containing magnetite (Fe ₃ O ₄ )] 100 A method of producing a grease composition for ultra-low noise, characterized in that it contains 5 to 15 parts by weight of magnetite (Fe ₃ O ₄ ) per part by weight. An ultra-low noise electrical and electronic product comprising the grease composition of any one of claims 1 to 4.