METHOD THEREOF

TECHNICAL FIELD The present invention relates to lubricant additive, particularly a graphene-polymer additive and a method to produce said additive.

BACKGROUND OF THE INVENTION

Friction is the force resisting the relative motion between two bodies in contact. In a moving mechanical system, the heat produced by friction in between the moving parts of said system leads to high consumption of fuel and energy. Therefore, it will affect the efficiency and performance of the mechanical system. Accordingly, lubrication technology has been introduced to reduce friction for improving energy efficiency and durability in the moving mechanical system. In recent decades, nanoparticle has been widely used as a lubricant additive to enhance the efficiency of lubricant.

Among various types of nanoparticles, graphene has drawn great attention due to its strong mechanical properties and unique sheet structure, which can be well dispersed in lubricant thereby enter the friction contact surfaces easily. Usually, graphene needs to undergo certain chemical modification before it becomes an additive for lubricant. However, the existing methods for producing modified graphene as an additive for lubricant is complicated and involve high consumption of chemicals. Hence, it is a need to provide a simple method to produce graphene-based additive with minimal chemical composition.

CN1 06317712A discloses an engine-oil-seal fluoride rubber and preparation method thereof. Said engine-oil-seal fluoride rubber contains 0.5 to 1.5 parts by mass of modified graphene per 100 parts by mass of fluororubber raw rubber. The modified graphene is the composite nano particles formed by calcining graphite oxide which was subjected to polyacrylamide surface modification and hydrogen oxidation co-precipitation. The method for preparing the modified graphene comprising the steps of dispersing graphene oxide in deionized water and adding a surfactant; adding polyacrylamide and heating the solution at the temperature of 60 to 80°C; adding sodium aluminate solution and the adjusting pH around 10 to 12 for obtaining the suspension; filtering and washing the suspension via spray shaping method; performing calcination at the temperature of 300 to 400°C for 1 to 6 hours to obtain the modified graphene.

CN107022399A discloses a sheet-shaped engine oil additive based on graphene and a preparation method thereof. Said engine oil additive comprises a main component and an auxiliary additive, wherein the main component is graphene and the auxiliary additive is a polymer material selected from bicyclic monoterpene ketone, alicyclic hydrocarbon and phenolic polymer material for dissolving in organic solvent, preferably the organic solvent is anhydrous ethanol. The method for preparing a sheet-shaped engine oil additive comprising the steps of dissolving graphene and the auxiliary additive in the organic solvent; stirring the mixture to form additive suspension liquid; filtering and drying the suspension to obtain graphene-containing powder; compressing the powder to obtain sheet-shaped engine oil additive.

CN110317665A discloses a graphene engine anti-wear repairing agent and a preparation method thereof. The graphene engine anti-wear repairing agent comprises 50 to 80 parts by weight of a base material, 5 to 12 parts by weight of a coupling agent, 6 to 15 parts by weight of a dispersant, 3 to 9 parts by weight of base oil and 2 to 8 parts by weight of alkylbenzene. The method for preparing a graphene engine anti-wear repairing agent comprising the steps of mixing the coupling agent and dispersing agent with the base material at the temperature of 85 to 90°C for 1 to 2 hours to obtain mixture A; recovering and evaporating petroleum ether and vacuum drying the mixture A at the temperature of 100 to 150°C for 3 hours to obtain modified graphene; stirring and adding a base oil and alkylbenzene oil to the modified graphene to obtain mixture B; filtering the mixture B to obtain graphene engine anti-wear repairing agent. The aforesaid graphene-based lubricant additives require additional chemical compounds to modify graphene and auxiliary additive to facilitate the dissolving of additive into the lubricant. Also, the aforesaid graphene-based lubricant additives production methods are complicated and time consuming. Accordingly, the above-mentioned prior arts are lacking of a cost effective graphene-polymer additive for lubricant and a simple method to produce the same.

Hence, there is a need to provide a graphene-polymer additive for lubricant having improved dispersion and anti-wear properties which involve lower production cost and simpler production method for enhancing the performance of a moving mechanical system.

SUMMARY OF THE INVENTION It is an objective of the present invention to provide a cost effective graphene-polymer additive for lubricant with minimal chemicals composition.

It is further an objective of the present invention to provide a graphene- polymer additive for lubricant with improved dispersion properties.

It is also another objective of the present invention to provide a graphene-polymer additive for lubricant with improved anti-wear properties.

It is yet another objective of the present invention to provide a simple method for producing graphene-polymer additive for lubricant.

Accordingly, these objectives may be achieved by following the teachings of the present invention. The present invention provides an additive composition for lubricant and production method thereof.

The present invention discloses an additive composition for lubricant, said composition comprising graphene-polymer, characterized in that said graphene-polymer comprising: 1 to 100 parts of graphene; at least one monomer; 1 to 100 parts of an organic solvent; and 0.01 to 30 parts of organosulfur compound.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

So that the manner in which the above recited features of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may have been referred by embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawing illustrate only typical embodiments of this invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

These and other features, benefits, and advantages of the present invention will become apparent by reference to the following text figure, with like reference numbers referring to like structures across the views, wherein:

Fig. 1 is a flow chart of a method for producing graphene-polymer addictive for lubricant in accordance to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

While the present invention is described herein by way of example using embodiments and illustrative drawings, those skilled in the art will recognize that the invention is not limited to the embodiments of drawing or drawings described, and are not intended to represent the scale of the various components. Further, some components that may form a part of the invention may not be illustrated in certain figures, for ease of illustration, and such omissions do not limit the embodiments outlined in any way. It should be understood that the drawings and detailed description thereto are not intended to limit the invention to the particular form disclosed, but on the contrary, the invention is to cover all modifications, equivalents, and alternatives falling within the scope of the present invention as defined by the appended claim. As used throughout this description, the word "may" is used in a permissive sense (i.e. meaning having the potential to), rather than the mandatory sense, (i.e. meaning must). Further, the words "a" or "an" mean "at least one” and the word “plurality” means “one or more” unless otherwise mentioned. Furthermore, the terminology and phraseology used herein is solely used for descriptive purposes and should not be construed as limiting in scope. Language such as "including," "comprising," "having," "containing," or "involving," and variations thereof, is intended to be broad and encompass the subject matter listed thereafter, equivalents, and additional subject matter not recited, and is not intended to exclude other additives, components, integers or steps. Likewise, the term "comprising" is considered synonymous with the terms "including" or "containing" for applicable legal purposes. Any discussion of documents, acts, materials, devices, articles and the like is included in the specification solely for the purpose of providing a context for the present invention. It is not suggested or represented that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present invention.

In this disclosure, whenever a composition or an element or a group of elements is preceded with the transitional phrase “comprising”, it is understood that we also contemplate the same composition, element or group of elements with transitional phrases “consisting of”, “consisting”, “selected from the group of consisting of, “including”, or “is” preceding the recitation of the composition, element or group of elements and vice versa.

The present invention is described hereinafter by various embodiments with reference to the accompanying drawing, wherein reference numerals used in the accompanying drawing correspond to the like elements throughout the description. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein. Rather, the embodiment is provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the following detailed description, numeric values and ranges are provided for various aspects of the implementations described. These values and ranges are to be treated as examples only, and are not intended to limit the scope of the claims. In addition, a number of materials are identified as suitable for various facets of the implementations. These materials are to be treated as exemplary, and are not intended to limit the scope of the invention. Referring to the drawings, the invention will now be described in more detail.

The present invention relates to a graphene-polymer additive for lubricant in a moving mechanical system; wherein the composition of graphene- polymer comprises 1 to 100 parts of graphene, at least a monomer, 1 to 100 parts of an organic solvent, and 0.01 to 30 parts of organosulfur compound.

In a preferred embodiment of the present invention, the graphene is graphene sheets.

In a preferred embodiment of the present invention, the monomer is selected from the group consisting of acrylic acid, propylene, ethylene, methylacrylic acid, isobutylene, vinyl chloride, styrene and ethylene propylene diene.

In a preferred embodiment of the present invention, the organic solvent is selected from the group consisting of chloroform, toluene, diethoxytrimethylamine and dimethylformamide.

In a preferred embodiment of the present invention, the organosulfur compound is selected from the group consisting of naphthalenethiol, nitrosothiols or thiocarboxylic acids. In a preferred embodiment of the present invention, the graphene- polymer is produced via a facile in-situ method. Referring to Figure 1 , the method for producing said graphene-polymer composition comprising the steps of dissolving graphene in monomers and solvent to form a first mixture; dissolving organosulfur compound into the first mixture to form a second mixture; and reacting the second mixture at a temperature of 60 to 120°C for 12 to 48 hours to obtain the graphene-polymer which act as an additive for lubricant. Hereinafter, example of the present invention will be provided for more detailed explanation. The advantages of the present invention may be more readily understood and put into practical effect from these examples. However, it is also to be understood that the following examples are not to limit the scope of the present invention in any way.

EXAMPLE

10 parts of graphene was dissolved in monomers and 20 parts of organic solvent to form a first mixture; 0.5 parts of organosulfur compound was dissolved into the first mixture to form a second mixture; and the second mixture was reacted at the temperature of 60 to 120°C for 12 to 48 hours to obtain graphene-polymer. After that, 0.02 mg/ml of graphene-polymer was added into lubricant by stirring and heating. RESULTS

Table 1 shows the comparison on the reduction of friction coefficient and reduction on wear rate between graphene-polymer of the present invention and the other graphene-based materials of the prior arts. The result shows that the graphene-polymer additive of the present invention achieved highest reduction on friction coefficient and wear rate among the graphene-based materials. The friction coefficient and wear rate can be reduced more than 90% by adding 0.02 mg/ml of graphene-polymer additive into lubricant. Said result indicates that the moving mechanical system able to achieve higher efficiency and higher durability just by introducing a small concentration of graphene-polymer additive produced by the present invention into lubricant. The concentration of graphene-polymer may be varied according to the types of lubricant.

Table 1 : Comparison on the reduction of friction coefficient and wear rate based on different graphene-based materials

The graphene-polymer additive of the present invention possesses improved dispersion properties thereby allowing said additive to be fully dispersed in lubricant by stirring and heating without addition of auxiliary chemical. Further, the graphene-polymer additive with high surface area and high affinity for metal surface enable penetration and coating of an asperity to form a thin protective film between the moving parts of the mechanical system for reducing the friction and enhancing the anti-wear effects.

Various modifications to these embodiments are apparent to those skilled in the art from the description and the accompanying drawings. The principles associated with the various embodiments described herein may be applied to other embodiments. Therefore, the description is not intended to be limited to the embodiments shown along with the accompanying drawings but is to be providing broadest scope of consistent with the principles and the novel and inventive features disclosed or suggested herein. Accordingly, the invention is anticipated to hold on to all other such alternatives, modifications, and variations that fall within the scope of the present invention and appended claim.