WO2014178669A1 - Engine oil additive composition comprising nanodiamond and method for preparing same - Google Patents

Abstract

The present invention relates to an engine oil additive composition, whereby a hydrophobically surface-modified nanodiamond is capable of being stably dispersed in oil for a long time by being used together with a specific dispersant. According to the present invention, the nanodiamond is stably dispersed in the engine oil for a long time, thereby reducing friction and abrasion of the machine such as an engine and thus improving fuel efficiency.

Description

Engine oil additive composition comprising nanodiamond, and a method of manufacturing the same

The present invention relates to an engine oil additive composition, and a method for producing the same. Specifically, it relates to an engine oil additive composition in which nanodiamonds are well dispersed in oil.

Engine oil reduces the friction between metal and metal, exhausts the heat generated from the inside to the outside to cool the engine parts, pumps easily to the main engine parts at low temperatures, and removes harmful debris to remove the internal parts. It keeps clean and maintains stability even at high temperatures to help improve fuel efficiency. In other words, engine oil plays an important role in the performance of low fuel consumption of internal combustion engines by performing functions such as lubrication, cooling, corrosion prevention, cleaning, etc. in automobiles, ships, and airplanes equipped with internal combustion engines. do.

However, engine oils tend to deteriorate in performance due to the deposition of contaminants in the oil and the chemical changes occurring in the oil, in particular the generation of oxidative products.

The main reason why contaminants accumulate in the engine is that abrasion occurs due to metal-to-metal collisions due to insufficient oil supply during engine operation. In particular, a large amount of such wear occurs at the start of the engine, which occurs because the oil is made of a flowable material, and thus is not smoothly supplied at the start of the engine. In addition, even when the engine is in a high temperature state, the oil does not form a smooth film and wears well.

In addition, the wear-prone metal reacts with other chemical additives in oil to easily oxidize or form secondary oxidation products, which adversely affects the engine.

Therefore, as one of the ways to further improve the performance of the engine oil, research and development on the engine oil additive, or the engine oil composition comprising the same has been actively made, and recently added nanodiamond to the engine oil to improve the wear resistance The technology to let is developed.

For example, Korean Patent No. 10-1205640 relates to a method of preparing nanodiamonds hydrophobicly surface treated using fatty acids and a lubricant including the same, comprising: adding nanodiamonds to oil to form a first mixture ; Adding a mono unsaturated fatty acid and an amine compound to the first mixture to form a second mixture; And a hydrophobic surface-treated nanodiamond comprising a sonication or milling the second mixture with a ball mill, and the lubricant containing the nanodiamond thus prepared has a low coefficient of friction and thus has excellent wear characteristics. It is starting point.

By the way, in the case of Korean Patent No. 10-1205640, only the dispersion safety of the disclosed hydrophobic surface-treated nanodiamond particles has a problem that it does not have a dispersibility safely for a long time in the engine oil.

Accordingly, the present inventors have studied the engine oil additive composition capable of stably dispersing hydrophilic nanodiamond particles in oil for a long time, and as a result, have completed the present invention.

It is an object of the present invention to provide an engine oil additive composition in which nanodiamonds can be stably dispersed in engine oil for a long time.

It is also an object of the present invention to provide an engine oil additive composition in which hydrophobic surface-modified nanodiamonds can improve fuel efficiency by improving the lubrication function of engine oil.

In order to achieve the above object, the engine oil additive composition according to the present invention,

Base oils;

Hydrophobically surface modified nanodiamonds; And

As the dispersing agent, oleylamine, polyalkenyl succinimide, and oleic acid;

It includes.

The engine oil additive composition,

Base oil 60 to 99% by weight;

0.001 to 0.5% by weight of hydrophobically modified nanodiamonds;

As the dispersant, 0.05 to 10% by weight of oleylamine, 0.01 to 5% by weight of polyalkenyl succinimide, and 0.5 to 35% by weight of oleic acid;

According to another aspect of the invention, the hydrophobic surface-modified nanodiamond,

Treating the nanodiamond with at least one acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, and hydrogen peroxide (first step); And

Reacting the nanodiamonds acid-treated in the first step with at least one acid chloride selected from the group consisting of thionyl chloride, phosphorus trichloride, and phosphorus pentachloride (second step); And

Reacting the nanodiamonds obtained in the second step with an alkylamine having 16 to 18 carbon atoms (step 3).

It is preferable that the said polyalkenyl succinimide is polyisobutenyl succinimide, and it is preferable that the said polyisobutenyl group is a number average molecular weight 300-10,000.

In addition, according to another aspect of the present invention, as a method for producing an engine oil additive composition,

Treating the nanodiamond with at least one acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, and hydrogen peroxide (first step);

Reacting the nanodiamonds acid-treated in the first step with at least one acid chloride selected from the group consisting of thionyl chloride, phosphorus trichloride, and phosphorus pentachloride (second step); And

Reacting the nanodiamonds obtained in the second step with an alkylamine having 16 to 18 carbon atoms (third step); to prepare the nanodiamonds surface-modified hydrophobicly through

Mixing the hydrophobic surface-modified nanodiamond with oleylamine and dispersing by ultrasonic wave to obtain a dispersion (fourth step); And

A polyalkenyl succinimide, oleic acid, and base oil in the dispersion obtained in the fourth step, and dispersing by ultrasonic wave (step 5).

Hereinafter, a look at the configuration of the present invention in more detail.

The engine oil additive composition of the present invention comprises a) base oil, b) hydrophobically modified nanodiamonds, and c) specific dispersants such as oleylamine, polyalkenyl succinimide, and oleic acid. (oleic acid).

The base oil a) used in the present invention can be appropriately selected from mineral oils and synthetic oils that are normally used as base oils for lubricating oils for internal combustion engines, and are not particularly limited.

The mineral oil is a high boiling oil obtained by vacuum distillation from crude oil, and is a colorless and transparent oil obtained through an isomerization reaction by removing unsaturated double bonds, cyclic compounds, etc. through a purification process such as a hydrogenation process.

On the other hand, as synthetic oil which is a synthesized base oil, PAO (poly-alpha-olefin, poly-alpha-olefin), a polyol ester, a wax cracking hydrocarbon, etc. are mentioned.

In the present invention, as the base oil, any one or two or more of the mineral oils and the synthetic oils may be used in combination.

The base oil is used in the range of 60 to 99% by weight in 100% by weight of the engine oil additive composition.

In the present invention, b) the nanodiamond particles as raw materials are used after surface modification to hydrophobicity.

Nanodiamond particles used as raw materials in the present invention is produced by the explosion method, the average particle diameter is 4 ~ 6nm, the amorphous carbon compound remains on the surface, surrounded by oxygen or hydrogen compounds, most of the particles The grains are agglomerated to form aggregates.

In the present invention, a method of surface modification of the nanodiamond particles hydrophobicly, first, by treating the nanodiamond with an acid, a carboxyl group (ND-COOH) is formed on the surface of the nanodiamond particles. Here, the acid used is preferably used by mixing one or two or more selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, and hydrogen peroxide.

In particular, in forming the carboxyl group on the surface of the nanodiamond particles, it is preferable to treat hydrochloric acid, nitric acid, and hydrogen peroxide, because a large amount of oxygen contained in the hydrogen peroxide helps the formation of the carboxyl group. At this time, the mixing ratio of the acid to be treated is preferably in a weight ratio of hydrochloric acid: nitric acid: hydrogen peroxide, 2 to 4: 1: 1, and most preferably 3: 1: 1.

Next, the nanodiamond acid treated in the first step is reacted with an acid chloride to replace the carboxyl group formed on the surface of the nanodiamond particle with an acyl chloride group (ND-COCl). In this case, as the acid chloride used, one or more selected from the group consisting of thionyl chloride (SOCl ₂ ), phosphorus trichloride (PCl ₃ ), and phosphorus pentachloride (PCl ₅ ), which are acid chlorides of inorganic acids, may be used. Use O'Neill.

Then, alkylamine is reacted with the nanodiamond particles having the acyl chloride group formed thereon to form an alkylamide group. As said alkylamine, it is preferable to use hexadecylamine, heptadecylamine, and octadecylamine which are C16-C18 alkylamines, and especially, to form an octadecylamide group using C18-octadecylamine, When used with the dispersant of the present invention, there is an effect of obtaining long-term dispersion stability in base oil.

As described above, since the octadecylamide group is formed on the surface of the nanodiamond, the nanodiamond particles surface-modified hydrophobicly are more dispersed than the nanodiamond particles before the surface-modification hydrophobicly aggregated in the base oil and are not dispersed. It is effective.

In the present invention, the hydrophobic surface-modified nanodiamond particles are preferably used in an amount of 0.001 to 0.5% by weight based on 100% by weight of the total engine oil additive composition, and used in an amount of 0.005 to 0.1% by weight. It is more preferable to do.

When the amount of the nanodiamond particles is less than 0.001% by weight, it is difficult to expect the effect of improving wear resistance due to the nanodiamond particles, and when the amount of the nanodiamond particles exceeds 0.5% by weight, the amount of the dispersant used to maintain the dispersion safety of the nanodiamond particles is excessive. It is not desirable to do so.

On the other hand, when only nanodiamond particles having an octadecylamide group on the surface were dispersed in the engine oil, a problem was found that the dispersion stability was not excellent for a long time, and the present inventors combined the specific dispersant even after a lapse of time. The engine oil additive composition of the present invention can be stably dispersed.

That is, the present invention is c) as a specific dispersant, when using a combination of oleylamine, oleic acid and succinimide-based compound, nanodiamond (ND-ODA) particles having an octadecylamide group on the surface for a long time Could be dispersed stably.

In the present invention, a polyalkenyl succinimide such as polyisobutenyl succinimide or morpholinopropyl polyisobutenyl succinimide is used as the succinimide-based compound, Alternatively, morpholinopropyl octenyl succinimide, morpholinopropyl dodecenyl succinimide, dialkyl succinimide, and the like can be used.

In this invention, it is preferable to use polyalkenyl succinimide, and it is more preferable to use polyisobutenyl succinimide which has a polyisobutenyl group of average molecular weight 300-10,000.

As described above, the engine oil additive composition of the present invention is mixed with oleylamine to hydrophobic surface-modified nanodiamond particles, ie, ND-ODA particles, and dispersed by ultrasonic wave for 10 minutes to 1 hour. After obtaining, the polyalkenyl succinimide, oleic acid (oleic acid), and the base oil in the dispersion is prepared by ultrasonic dispersion for 2 hours to 4 hours by ultrasonic.

In this case, 0.05 to 10% by weight of oleylamine, 0.01 to 5% by weight of polyalkenyl succinimide, and oleic acid based on 0.001 to 0.5% by weight of hydrophobically modified nanodiamonds in 100% by weight of the engine oil additive composition. It is preferable to use 0.5 to 35% by weight to maintain the dispersion stability of the nanodiamond particles for a long time.

Next, it is preferable to use the engine oil additive composition of this invention at 3-10 weight part with respect to 100 weight part of engine oil.

The engine oil additive composition of the present invention has the effect of stably dispersing nanodiamonds in engine oil for a long time.

In addition, the engine oil additive composition of the present invention, by nano-diamonds are stably dispersed in the engine oil for a long time, there is an effect of improving the fuel economy by reducing friction and wear.

The engine oil additive composition of the present invention reduces the frictional heat and prevents degeneration, oxidation, and the like of the engine oil, thereby improving the life of the engine oil.

1 is a view showing the results of Fourier Transform Infrared Spectroscopy (FT-IR) analysis of nanodiamonds before acid treatment.

2 is a particle cross-sectional photograph of nanodiamonds analyzed by AFT (Atomic Force Microscopy) before acid treatment.

3 is FT-IR analysis data that can confirm that the COOH group is attached to the surface of the nanodiamond particles after the acid treatment.

4 is FT-IR analysis data that can confirm that the octadecylamide group is attached to the surface of the nanodiamond particles after surface modification with hydrophobicity.

5 is a diagram showing visual observation results immediately after preparing the samples of Examples 2 to 3 and Comparative Examples 1 to 8. FIG.

Hereinafter, a preferred embodiment of the present invention will be described in detail. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, it is provided to ensure that the contents introduced herein are thorough and complete, and that the spirit of the present invention to those skilled in the art can fully convey.

Example 1 Preparation of Surface-Modified NanoDiamond Particles

(1) acid treatment

Acid solution 120 containing 5 g of nanodiamond powder (ND) in a ratio of hydrochloric acid: nitric acid: hydrogen peroxide in a ratio of 3: 1: 1 It was sonicated for 4 hours after addition to ml. The solution was poured into distilled water and washed with water until the filtrate became neutral. After filtration, the product was completely dried at 100 ° C. to remove moisture to obtain particles (ND-COOH) in which COOH groups were formed on the nanodiamond surface.

In the case of ND powder before acid treatment, Fourier Transform Infrared Spectroscopy (FT-IR) analysis showed peaks for OH and CH as shown in FIG. 1, and Atomic Force Microscopy (AFM) analysis results. ND powder was agglomerated by the influence of moisture in the air and the cohesion of the powder itself. As can be seen from the particle cross-sectional photograph of FIG.

On the other hand, in the case of the ND powder after the acid treatment, FT-IR analysis showed a peak that can confirm the presence of -COOH to confirm that the COOH group is attached to the ND surface.

(2) surface modification to hydrophobicity

₂ g of the ND-COOH powder was dissolved in SOCl ₂ 400 After adding to ml and reacting at 70 ° C. for 24 hours, extra SOCl ₂ was washed with THF and the resulting powder was vacuum dried. 40 g of octadecylamine was added and reacted at 90-100 ° C. for 4 days. Afterwards, the excess octadecylamine was washed with the ethanol bath. The obtained particles were then stored under vacuum after complete removal of ethanol. The nanodiamond particle (ND-ODA) in which the octadecylamide group was formed in the surface was obtained.

<Example 2, Example 3, Comparative Examples 1 to 8> Preparation of the engine oil additive composition

According to the composition of the following [Table 1], the engine oil additive composition of Example 2, Example 3, and Comparative Examples 1-8 was prepared.

Examples 2 and 3 disperse the ND-ODA treated in Example 1 with oleylamine by ultrasound for about 30 minutes. Polyalkenyl succinimide, oleic acid, and base oil (S-oil's Ultra-S) are added and ultrasonically dispersed for 3 hours.

Table 1

Preparation of Engine Oil Additives Composition (wt%)
	ND	ND-ODA	OLA	SI	OA	ODA	base oil
Example 2 (sample 5)	-	0.005	0.058	0.032	1.641	-	98.264
Example 3 (sample 6)	-	0.010	0.116	0.027	3.282	-	96.565
Comparative Example 1	0.005	-	-	-	0.0005	0.0005	99.994
Comparative Example 2	-	0.010	-	-	-	-	99.990
Comparative Example 3	0.01	-	-	-	3.425	-	96.565
Comparative Example 4 (sample 7)	-	0.010	-	3.425	-	-	96.565
Comparative Example 5 (sample 8)	-	0.010	-	-	3.425	-	96.565
Comparative Example 6 (sample 9)	-	0.010	2.778	0.647	-	-	96.565
Comparative Example 7 (sample 10)	-	0.010	0.117	-	3.308	-	96.565
Comparative Example 8 (sample 11)	-	0.010	-	0.028	3.397	-	96.565
ND: hydrophobic nanodiamond before surface modification ND-ODA: hydrophobic surface-modified nanodiamond obtained in Example 1, ie nanodiamond-octadecylamide OLA: oleylamine SI: poly Isobutenyl succinimide OA: oleic acid ODA: octadecylamine

On the other hand, in Table 1, Comparative Example 1, as described in Examples 1 and 3 of the Patent No. 10-1205640, oil of nano diamond, oleic acid, dodecylamine in the ratio of 1: 0.1: 0.1 by weight of oil, respectively It was obtained by diluting in oil after treatment in ultrasonic and ball mill equipment for 1 hour or more.

In addition, Comparative Examples 2-8 are manufactured by the method similar to Example 2 using the combination of ND-ODA or ND and each dispersing agent or each dispersing agent of Table 1.

<Test Evaluation>

1. Visual observation

The samples of Examples 2 and 3 and Comparative Examples 1 to 8 were visually measured immediately after preparation. As a result, it was confirmed that precipitation was produced in the samples of Comparative Example 2, Comparative Example 5, Comparative Example 6, and Comparative Example 7. This is considered to be because in these samples, nanodiamond particles were aggregated because they were not properly dispersed from the beginning.

2. Dispersion Stability Test

Dispersion stability measuring equipment (Youngjin Corporation, LUMiSize) was used. Dispersion stability test instrument is a method of measuring the absorbance of the lower part of the cell where the particles are precipitated by forcibly settling the particles in the solution by applying gravity arbitrarily. The higher the transmittance at the bottom of the cell where the precipitation occurred, the better the dispersion stability.

The dispersion stability measuring device LUMiSize is a device that can measure the dispersion stability by STEP technology (Space & Time Resolved Extinction Profile Technology), the measuring principle is using a dispersion equipment (eg homogenizer, homomixer, ultrasonic) So that the dispersion of the liquid-emulsion, or liquid-suspension, takes place for a few months, depending on the degree of dispersion of the de-mixing process. It happens that the de-mixing process is most efficiently implemented in a very short time to measure the dispersion stability.

TABLE 2

Classification (sample No.)	Measurement start time (min)	Measurement completion time (min)	% (% / Min) of dispersed particles per hour
Example 2 (sample 5)	0.5243	10.02	0.0961
Example 3 (sample 6)	0.5262	10.02	0.0741
Comparative Example 1	0.4995	10.00	0.2784
Comparative Example 2	0.5082	10.01	Initial precipitation formation
Comparative Example 3	0.5095	10.01	0.2122
Comparative Example 4 (sample 7)	0.5108	10.03	0.2244
Comparative Example 5 (sample 8)	0.5418	10.03	Initial precipitation formation
Comparative Example 6 (sample 9)	0.5568	10.04	Initial precipitation formation
Comparative Example 7 (sample 10)	0.5583	10.04	Initial precipitation formation
Comparative Example 8 (sample 11)	0.5738	10.05	0.2146

As confirmed in Table 2 above, when the sedimentation rate after 10 minutes was confirmed by using the dispersion stability measuring device LUMiSize, the sedimentation rate of Example 2 and Example 3 was respectively 0.0961% / min and 0.0741% / The low point was found to be min. This low sedimentation rate means that the dispersion stability can be maintained stably for a long time due to high dispersion stability, and the engine oil additive composition of the present invention has a storage stability of 2 to 3 times or more than conventional products. It can be seen that the improved.

On the other hand, in Table 2, in the case of Comparative Examples 2, 5, 6, and 7, as confirmed in the visual observation of the above test evaluation 1. The precipitation occurred initially after generating the engine oil composition, nano It was confirmed that the diamond particles were agglomerated and not dispersed properly.

That is, in Examples 2 and 3 corresponding to the engine oil additive composition of the present invention, it is possible to obtain an engine oil additive composition in which nanodiamond particles are stably dispersed in oil, and at the same time, compared to Comparative Examples 1 to 8. It was confirmed that the effect of maintaining stability in the long term is excellent. As such, the engine oil additive composition of the present invention is not only excellent in long-term dispersion stability by using hydrophobic surface-modified nano diamond particles with a specific dispersant, but also reduces the friction coefficient to improve the lubricating function of the engine oil. There was.

Claims (4)

1. An engine oil additive composition comprising nano diamond,

   Base oil 60 to 99% by weight;

   0.001 to 0.5% by weight of hydrophobically modified nanodiamonds;

   As a dispersing agent, 0.05-10 weight% of oleylamine, 0.01-5 weight% of polyalkenyl succinimide, and 0.5-35 weight% of oleic acid;

   Engine oil additive composition comprising a.
2. The method of claim 1,

   The hydrophobic surface-modified nanodiamond,

   Treating the nanodiamond with at least one acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, and hydrogen peroxide (first step);

   Reacting the nanodiamonds acid-treated in the first step with at least one acid chloride selected from the group consisting of thionyl chloride, phosphorus trichloride, and phosphorus pentachloride (second step); And

   Reacting the nano-diamond obtained in the second step with an alkylamine having 16 to 18 carbon atoms (third step); engine oil additive composition characterized in that it was produced through.
3. The method of claim 1,

   Said polyalkenyl succinimide is polyisobutenyl succinimide, The engine oil additive composition characterized by the above-mentioned.
4. As a method for producing an engine oil additive composition,

   Treating the nanodiamond with at least one acid selected from the group consisting of hydrochloric acid, nitric acid, sulfuric acid, and hydrogen peroxide (first step);

   Reacting the nanodiamonds acid-treated in the first step with at least one acid chloride selected from the group consisting of thionyl chloride, phosphorus trichloride, and phosphorus pentachloride (second step); And

   Reacting the nanodiamonds obtained in the second step with an alkylamine having 16 to 18 carbon atoms (third step); to prepare the nanodiamonds surface-modified hydrophobicly through

   Mixing the hydrophobic surface-modified nanodiamond with oleylamine and dispersing by ultrasonic wave to obtain a dispersion (fourth step); And

   Adding polyalkenyl succinimide, oleic acid, and base oil to the dispersion obtained in the fourth step and dispersing by ultrasonic wave (step 5);

   Method for producing an engine oil additive composition comprising a.

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