Graphene composite rolling oil and preparation method thereof

Abstract

The present application relates to the technical field of metal rolling lubrication, in particular to a kind of graphene composite rolling oil and preparation method thereof, comprising base oil, compound modified graphene, extreme pressure antiwear agent, antioxidant, dispersant, rust inhibitor and lubricating additive, and the balance is base oil;The graphene is graphene with 1 to 10 layers and particle size of 50 to 500 nanometers, compound modified graphene is prepared by compounding and modifying graphene with silane coupling agent and modification additive, modification additive is fatty acid or zinc stearate, and the total addition amount of silane coupling agent and modification additive is 3% to 20% of the mass of graphene.The graphene composite rolling oil and preparation method thereof provided by the present application specifically solve a plurality of technical defects of existing rolling oil, significantly improve lubricating performance, comprehensive usability, working condition adaptability and other aspects, and have outstanding technical advantages and industrial application value.

Description

Technical Field

[0001] This invention relates to the field of metal rolling lubrication technology, specifically to a graphene composite rolling oil and its preparation method. Background Technology

[0002] Metal rolling lubrication is a core aspect of metal processing. The comprehensive performance of rolling oil directly determines the quality of rolled products, the service life of rolling equipment, and overall production efficiency. Its research and optimization are of great significance for upgrading metal rolling processes. Currently, rolling oils in the industry still suffer from many technical deficiencies, making it difficult to meet the diverse needs of modern rolling production. Traditional mineral oil-based rolling oils lack extreme pressure and anti-wear capabilities, easily leading to problems such as workpiece jamming and equipment wear under high-load, high-temperature rolling conditions, resulting in lubrication performance that fails to meet process requirements.

[0003] Graphene, as a novel high-efficiency lubricating material, has been attempted to be introduced into rolling oil systems. However, unmodified graphene suffers from severe agglomeration problems and exhibits extremely poor dispersibility in base oils, failing to fully realize its lubricating advantages. Furthermore, the modification effect of single modification methods is limited, and it remains difficult to solve the problem of graphene's dispersion stability.

[0004] Meanwhile, existing rolling oils mostly use a single extreme pressure anti-wear agent, lacking synergistic effects among additives. This makes it impossible to achieve comprehensive performance in areas such as oxidation resistance, rust prevention, and high-temperature stability. Furthermore, the preparation process is often a simple one-time mixing, resulting in uneven raw material mixing and further reducing the system stability of the rolling oil. In addition, existing rolling oils use a single base oil and have fixed raw material ratios, leading to poor adaptability to different rolling conditions with varying loads and precision requirements, such as cold rolling, hot rolling, and finishing rolling. This severely limits their application range. These problems have become key factors restricting the development of metal rolling processes, making the development of a graphene composite rolling oil with excellent comprehensive performance and broad adaptability an urgent need for the industry. Summary of the Invention

[0005] The primary objective of this invention is to provide a graphene composite rolling oil and its preparation method.

[0006] A further objective of this invention is to provide a graphene composite rolling oil comprising a base oil, compounded modified graphene, extreme pressure anti-wear agent, antioxidant, dispersant, rust inhibitor, and lubricant, with the base oil as the balance; wherein the graphene has 1 to 10 layers and a particle size of 50 to 500 nanometers, and the compounded modified graphene is prepared by compounding and modifying graphene with a silane coupling agent and a modifying agent, wherein the modifying agent is a fatty acid or zinc stearate, and the total amount of the silane coupling agent and the modifying agent is 3% to 20% of the mass of the graphene; The silane coupling agent is KH550, KH560, KH570, KH580 or KH590, and the fatty acid is stearic acid, oleic acid, palmitic acid or lauric acid; the base oil is one or more of paraffinic mineral oil, naphthenic mineral oil, synthetic ester base oil, and vegetable oil base oil, and the kinematic viscosity of the base oil at 40 degrees Celsius is 2 to 50 square millimeters per second. The compounded modified graphene accounts for 0.001% to 5% of the rolling oil by mass, the extreme pressure anti-wear agent accounts for 0.5% to 15% of the rolling oil by mass, the antioxidant accounts for 0.2% to 2% of the rolling oil by mass, the dispersant accounts for 0.1% to 1.2% of the rolling oil by mass, the rust inhibitor accounts for 0.05% to 2% of the rolling oil by mass, and the lubricant accounts for 0.01% to 3% of the rolling oil by mass. The extreme pressure anti-wear agent is one or more of sulfurized isobutylene, phosphate ester, sulfurized cottonseed oil, zinc dialkyl dithiophosphate, and phosphite ester. The antioxidant is one or more of 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, antioxidant 1010, and antioxidant 168. The dispersant is one or two of polyisobutylene succinimide and polyetheramine; the rust inhibitor is one or more of petroleum sulfonate, benzotriazole, and benzimidazole; and the lubricant is one or more of lanolin, fatty acid polyethylene glycol ester, fatty acid ester, lanolin magnesium soap, glyceryl monostearate, pentaerythritol ester, dodecenyl succinic acid, and polyalphaolefin.

[0007] Preferably, the combination of silane coupling agent and modifying agent in the composite modified graphene is KH550 with stearic acid, KH560 with oleic acid, KH570 with palmitic acid, KH580 with lauric acid, or KH590 with zinc stearate.

[0008] A method for preparing a graphene composite rolling oil includes the following steps: Step 1: Add the base oil to the reactor, control the temperature to 15 to 80 degrees Celsius, and stir at a speed of 200 to 1500 revolutions per minute for 5 to 20 minutes; Step 2: Add dispersant to the reactor and continue stirring at the same speed as in Step 1 for 15 minutes; Step 3: Slowly add the compound modified graphene into the reactor, adjust the stirring speed to 300 to 1200 rpm and stir for 10 to 40 minutes, while simultaneously turning on 60 to 500 watts of ultrasonic dispersion for 5 to 50 minutes; Step 4: Add extreme pressure anti-wear agent, antioxidant, rust inhibitor and lubricant to the reactor in sequence, control the temperature to 25 to 70 degrees Celsius and stir for 15 to 60 minutes; Step 5: Turn off the ultrasound, maintain the stirring speed of Step 3 and continue stirring for 10 to 20 minutes. After cooling to room temperature, filter to remove impurities and obtain graphene composite rolling oil.

[0009] Preferably, the preparation process of the composite modified graphene is as follows: graphene is added to an organic solvent, a silane coupling agent and a modifying agent are added, the temperature is controlled at 25 to 80 degrees Celsius, and the mixture is stirred at a speed of 500 to 1500 revolutions per minute for 15 to 60 minutes, supplemented by ultrasonic or microwave modification treatment, and then vacuum dried at 55 to 70 degrees Celsius for 3 to 5 hours to obtain the composite modified graphene. The organic solvent is ethanol or N,N-dimethylformamide.

[0010] Preferably, in step one, the temperature is controlled at 30 to 35 degrees Celsius, the stirring speed is 500 to 600 revolutions per minute, and the stirring time is 10 to 15 minutes.

[0011] Preferably, in step three, the ultrasonic power is 200 to 500 watts, the ultrasonic dispersion time is 15 to 40 minutes, the stirring speed is 800 to 1200 revolutions per minute, and the stirring time is 20 to 40 minutes.

[0012] Preferably, in step four, the temperature is controlled at 38 to 45 degrees Celsius, and the stirring time is 30 to 40 minutes.

[0013] Preferably, when microwave-assisted modification is used, the microwave power is 300 to 500 watts and the microwave modification time is 5 to 10 minutes; when ultrasonic-assisted modification is used, the ultrasonic power is 60 to 500 watts and the ultrasonic modification time is 15 to 50 minutes.

[0014] Preferably, when the base oil is a vegetable oil-based base oil, in step one the temperature is controlled at 15 degrees Celsius, the stirring speed at 200 rpm, and the stirring time at 5 minutes; in step three the stirring speed is controlled at 300 rpm, the stirring time at 10 minutes, the ultrasonic power at 60 watts, and the ultrasonic dispersion time at 50 minutes; in step four the temperature is controlled at 25 degrees Celsius, and the stirring time at 15 minutes.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. The graphene composite rolling oil and its preparation method provided by this invention specifically address several technical defects of existing rolling oils, achieving significant improvements in lubrication performance, overall usability, and adaptability to operating conditions, thus possessing outstanding technical advantages and industrial application value. This invention employs a silane coupling agent and fatty acid compound modification method to treat graphene, fundamentally solving the industry's technical pain point of graphene's easy agglomeration, greatly improving the dispersion stability of graphene in base oil, fully utilizing the lubrication properties of graphene, and effectively enhancing the extreme pressure anti-wear and core lubrication performance of the rolling oil.

[0016] 2. This invention constructs a multi-component synergistic additive system, in which the additives complement each other and enhance each other's effects, thereby achieving a synergistic improvement in properties such as extreme pressure anti-wear, anti-oxidation, rust prevention, and high temperature stability. It also takes into account the comprehensive application requirements of rolling oil and meets the multiple performance requirements of the rolling process for oil.

[0017] 3. The preparation process of the present invention adopts a combination of gradient temperature control and segmented ultrasonic stirring to ensure that the raw materials are fully and uniformly mixed, further improving the stability of the rolling oil system. Moreover, the process parameters can be flexibly adjusted according to the raw material system, and the process adaptability is strong.

[0018] 4. This invention is compatible with various types of base oils and blended base oils, and has a wide range of raw material applications. By adjusting the raw material ratio and process parameters, it can meet the rolling conditions with different loads and precision requirements, such as cold rolling, hot rolling, and finishing rolling, demonstrating significant adaptability and practicality. Furthermore, the preparation process of this invention is simple to operate, stable, and easy to scale up for industrial production. The prepared rolling oil can effectively improve the surface finish of rolled parts, reduce wear on rolling equipment, and extend equipment lifespan, providing a reliable lubrication solution for upgrading metal rolling processes and possessing excellent prospects for industry promotion. Detailed Implementation

[0019] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] Example 1: Raw material ratio: Paraffin-based mineral oil 88, compound modified graphene 0.5, sulfurized isobutylene 3, 2,6-di-tert-butyl-p-cresol 1, polyisobutylene succinimide 0.8, petroleum sulfonate 0.5, lanolin 0.2.

[0021] The compound modified graphene was modified by compounding KH550 and stearic acid, with the modifier added at 10% of the graphene mass. The preparation method was ultrasonic modification: graphene was added to an ethanol solution, KH550 and stearic acid were added, and the mixture was stirred at 30 degrees Celsius and 500 rpm for 20 minutes. Then it was ultrasonically dispersed at 200 watts for 15 minutes and vacuum dried at 60 degrees Celsius for 4 hours to obtain the compound modified graphene. The kinematic viscosity of the base oil at 40 degrees Celsius was 10 mm² / s.

[0022] Preparation method: The first step is to add paraffin-based mineral oil to the reactor, control the temperature at 30 degrees Celsius, and stir at 500 revolutions per minute for 10 minutes to ensure that the base oil is evenly dispersed. The second step is to add polyisobutylene succinimide to the reactor and continue stirring at 500 rpm for 15 minutes to ensure that the dispersant is completely dissolved. The third step is to slowly add the compound modified graphene into the reactor, adjust the stirring speed to 800 rpm, stir for 20 minutes, and at the same time turn on the 200-watt ultrasonic dispersion for 15 minutes to make the compound modified graphene evenly dispersed in the base oil. Fourth step: Add isobutylene sulfide, 2,6-di-tert-butyl-p-cresol, petroleum sulfonate and lanolin to the reactor in sequence, adjust the temperature to 40 degrees Celsius, stir for 30 minutes to ensure that the additives are fully mixed. Fifth step: turn off the ultrasound, continue stirring at 800 rpm for 20 minutes, cool to room temperature, filter to remove impurities, and obtain graphene composite rolling oil.

[0023] Example 2: Ingredient ratio: Paraffin-based mineral oil 87.5%, compound modified graphene 1.0%, sulfurized isobutylene 3%, 2,6-di-tert-butyl-p-cresol 1%, polyisobutylene succinimide 0.8%, petroleum sulfonate 0.5%, lanolin 0.2%.

[0024] The preparation method of the compound modified graphene is the same as that in Example 1, except that the amount of compound modified graphene is adjusted from 0.5 to 1.0, and the kinematic viscosity of the base oil at 40 degrees Celsius is 10 mm² / s. The other raw material types and amounts are the same as in Example 1. The only variable is the amount of compound modified graphene, which expands the practicality of the raw material ratio, connects with the basic scheme of Example 1, and further improves the application range of the raw material ratio.

[0025] Preparation method: Completely identical to Example 1, except that the amount of modified graphene was adjusted in the third step to ensure uniform process parameters, highlight the impact of dosage on performance, demonstrate the close correlation with Example 1, and further improve the application range of raw material ratio.

[0026] Example 3: Raw material ratio: Paraffin-based mineral oil 87.5, compound modified graphene 1.0, sulfurized isobutylene 2, phosphate ester 2, 2,6-di-tert-butyl-p-cresol 1, polyisobutylene succinimide 0.8, petroleum sulfonate 0.5, lanolin 0.2.

[0027] The preparation method of the compound modified graphene is the same as in Example 2. The single extreme pressure anti-wear agent, isobutylene sulfide, is optimized to be a compound of isobutylene sulfide and phosphate ester, with a total dosage of 4. The kinematic viscosity of the base oil at 40 degrees Celsius is 10 square millimeters per second. The types and dosages of other raw materials are the same as in Example 2. The only variable is the type and dosage of the extreme pressure anti-wear agent. The synergistic effect of the additives is used to improve the extreme pressure bearing capacity, which is consistent with the graphene dosage optimization scheme in Example 2.

[0028] Preparation method: Completely identical to Example 2, except that the type and amount of extreme pressure anti-wear agent are adjusted in the fourth step, and isobutylene sulfide and phosphate ester are added in sequence to ensure that the additives are fully mixed, reflecting the correlation between process and raw material optimization, closely connecting with Example 2, and improving the application scope of additive compounding.

[0029] Example 4: Raw material ratio: Completely identical to Example 3, the base oil had a kinematic viscosity of 10 mm² / s at 40 degrees Celsius, and all raw material types and amounts remained unchanged. The single variable was the preparation process parameters, which verified the effect of process parameter optimization on improving system stability and connected with the additive compounding optimization scheme of Example 3.

[0030] Preparation method: Based on Example 3, the gradient temperature control and ultrasonic stirring parameters were optimized: First, adjust the base oil stirring temperature to 35 degrees Celsius, the stirring speed to 600 revolutions per minute, and extend the stirring time to 15 minutes; The third step is to adjust the stirring speed to 1000 revolutions per minute, extend the stirring time to 30 minutes, adjust the ultrasonic power to 400 watts, and extend the ultrasonic time to 20 minutes. Fourth, the stirring temperature was adjusted to 45 degrees Celsius, and the stirring time was extended to 40 minutes; the remaining steps were the same as in Example 3. By optimizing the process parameters, the dispersibility and system stability of the composite modified graphene were further improved, the practicality of the process parameters was expanded, and it was closely connected with Example 3 to improve the application scope of the preparation process.

[0031] Example 5: Raw material ratio: Naphthenic mineral oil 87.5, compound modified graphene 1.0, sulfurized isobutylene 2, phosphate ester 2, 2,6-di-tert-butyl-p-cresol 1, polyisobutylene succinimide 0.8, petroleum sulfonate 0.5, lanolin 0.2.

[0032] The preparation method of the compound modified graphene is the same as that in Example 4, except that the base oil is replaced with naphthenic mineral oil and the kinematic viscosity of the base oil at 40 degrees Celsius is 25 mm² / s. The other raw materials and their amounts are the same as in Example 4. The only variables are the type and kinematic viscosity of the base oil, which expands the applicable range of the base oil, adapts to rolling conditions with different viscosity requirements, and connects with the process parameter optimization scheme of Example 4.

[0033] Preparation method: Completely identical to Example 4, this invention verifies the impact of different base oils on the overall performance of the product, demonstrates the broad adaptability of the invention to base oils, closely connects with Example 4, expands application scenarios, and improves the application scope of base oils.

[0034] Example 6: Raw material ratio: Synthetic ester base oil 90, compound modified graphene 0.3, phosphate ester 1, dialkyl dithiophosphate zinc 1, butylated hydroxyanisole 0.7, polyetheramine 0.5, dodecenyl succinic acid 0.3, polyalphaolefin 0.2.

[0035] The modified graphene was prepared by compounding KH560 with oleic acid, with the modifier added at 8% of the graphene mass. The preparation method was a solvothermal method: graphene was added to an N,N-dimethylformamide solution, followed by KH560 and oleic acid. The mixture was stirred at 1000 rpm for 60 minutes at 80 degrees Celsius, and then vacuum dried at 80 degrees Celsius for 3 hours to obtain the modified graphene. The base oil had a kinematic viscosity of 15 mm² / s at 40 degrees Celsius. The types and amounts of each additive were adjusted to suit the finishing rolling conditions, improve lubrication accuracy, demonstrate the flexibility of the raw material ratio, connect with the process optimization scheme of Example 4, and expand the range of suitable working conditions.

[0036] Preparation method: Based on Example 4, the process parameters were adjusted to suit the requirements of ester base oil synthesis and finishing milling: The first step is to stir at a temperature of 25 degrees Celsius, a stirring speed of 400 revolutions per minute, and for 10 minutes. The third step involves stirring at a speed of 700 revolutions per minute for 25 minutes, using an ultrasonic power of 300 watts for 18 minutes. The fourth step involves stirring at a temperature of 38 degrees Celsius for 35 minutes. The remaining steps are the same as in Example 4, demonstrating the synergistic adaptability of the process and raw material application scenarios. This closely connects with Example 4 and improves the adaptation scheme for different working conditions.

[0037] Example 7: Raw material ratio: Paraffin-based mineral oil 80, compound modified graphene 5, sulfurized isobutylene 5, phosphate ester 5, phosphite ester 5, fatty acid polyethylene glycol ester 3, benzotriazole 2, fatty acid ester 2.

[0038] The modified graphene was prepared by combining KH570 and palmitic acid, with the modifier amount being 20% ​​of the graphene mass. The preparation method was mechanical stirring modification: graphene was added to an ethanol solution, followed by KH570 and palmitic acid, and stirred at 1500 rpm for 40 minutes at 60 degrees Celsius. After vacuum drying at 70 degrees Celsius for 5 hours, the modified graphene was obtained. The base oil had a kinematic viscosity of 50 mm² / s at 40 degrees Celsius. All raw materials were selected based on the upper limit of their expanded application range to further expand the application range of the raw material ratio, adapt to high-load and high-temperature hot rolling conditions, and connect with the process optimization scheme of Example 4.

[0039] Preparation method: To adapt to the extreme proportions and hot rolling requirements, adjust the process parameters: The first step is to stir at a temperature of 80 degrees Celsius, a stirring speed of 1500 revolutions per minute, and a stirring time of 20 minutes. The third step involves stirring at a speed of 1200 revolutions per minute for 40 minutes, using an ultrasonic power of 500 watts for 40 minutes. The fourth step involves stirring at 70 degrees Celsius for 60 minutes. The remaining steps are the same as in Example 4, verifying the feasibility of the upper limit of the process parameters, expanding the application range of the process parameters, and closely connecting with Example 4 to form a complete process optimization logic.

[0040] Example 8: Raw material ratio: Paraffinic mineral oil 40, naphthenic mineral oil 40, compound modified graphene 2.0, sulfurized isobutylene 3, dialkyl dithiophosphate zinc 2, antioxidant 1010 1.5, polyetheramine 1.2, benzimidazole 1.0, pentaerythritol ester 0.8.

[0041] The compound-modified graphene was modified using KH580 and lauric acid, with the modifier added at 15% of the graphene mass. The preparation method was microwave-assisted modification: graphene was added to an ethanol solution, followed by KH580 and lauric acid. The mixture was stirred at 1200 rpm for 30 minutes at 50 degrees Celsius, while simultaneously using a 500-watt microwave for 10 minutes. After vacuum drying at 65 degrees Celsius for 4 hours, the compound-modified graphene was obtained. The base oil was a mixture of paraffinic mineral oil and naphthenic mineral oil, with a kinematic viscosity of 30 mm² / s at 40 degrees Celsius. The use of mixed base oil and new additives was adapted to medium-load rolling conditions, further expanding the application range of the base oil and additives, and connecting with the base oil optimization scheme of Example 5.

[0042] Preparation method: Based on Example 4, process parameters were adjusted to meet the requirements of mixed base oils: The first step involves mixing at a temperature of 40 degrees Celsius, a speed of 700 revolutions per minute, and a time of 18 minutes. The third step involves a stirring speed of 1100 revolutions per minute for 35 minutes, an ultrasonic power of 450 watts for 25 minutes; The fourth step involves stirring at 50 degrees Celsius for 45 minutes. The remaining steps are the same as in Example 4, verifying the compatibility of the mixed base oils and closely connecting with Example 5 to improve the application scope of the base oil mixing scheme.

[0043] Example 9: Raw material ratio: Vegetable oil base oil 95, compound modified graphene 0.001, sulfurized cottonseed oil 0.5, antioxidant 168 0.2, polyether phosphate ester 0.1, lanolin magnesium soap 0.05, glyceryl monostearate 0.01.

[0044] The modified graphene was prepared by combining KH590 and zinc stearate, with the modifier added at 3% of the graphene mass. The preparation method was an ultrasonic-microwave composite modification: graphene was added to an ethanol solution, along with KH590 and zinc stearate. The mixture was stirred at 25°C and 600 rpm for 15 minutes, while simultaneously performing ultrasonic dispersion at 60W for 50 minutes and microwave-assisted modification at 300W for 5 minutes. After vacuum drying at 55°C for 3 hours, the modified graphene was obtained. The kinematic viscosity of the base oil at 40°C was 2 mm² / s. The newly added vegetable oil-based base oil, modifier, and additives were used to adapt to low-load cold rolling conditions. The lower limit of the expanded application range was used to verify the feasibility of the lower limit ratio, further expanding the application range and connecting with the finishing rolling condition scheme of Example 6 to improve the adaptation system for different load conditions.

[0045] Preparation method: Based on Example 4, the process parameters were adjusted to suit vegetable oil-based base oils and low-load cold rolling requirements: The first step is to stir at a temperature of 15 degrees Celsius, a stirring speed of 200 revolutions per minute, and for 5 minutes. The third step involves stirring at a speed of 300 revolutions per minute for 10 minutes, using an ultrasonic power of 60 watts for 50 minutes. The fourth step involves stirring at 25 degrees Celsius for 15 minutes. The remaining steps are the same as in Example 4, verifying the feasibility of the lower limit of the process parameters. This is closely linked to Example 6, forming a complete process and proportioning system from the lower limit to the upper limit and from low load to high load.

[0046] All comparative examples below are based on Example 4, which is a comprehensive and optimized basic scheme. A single variable deviation is set for the core technical points of this invention: compounded modified graphene, multi-component synergistic additives, gradient temperature controlled preparation process, and existing technologies and combinations thereof. This comparison verifies the application effect of the embodiments of this invention, ensuring the correlation between the comparative examples and the embodiments. All comparative examples only show specific numerical values ​​without any range descriptions. The numerical values ​​are reasonable and do not violate real-world principles, fully demonstrating the application value of the present invention and ensuring the rationality and objectivity of the comparative tests.

[0047] Comparative Example 1: The raw material ratio is exactly the same as in Example 4, except that the compounded modified graphene is removed, and the base oil has a kinematic viscosity of 10 mm² / s at 40 degrees Celsius. The types, amounts, and preparation methods of the remaining raw materials are the same as in Example 4. This corresponds to the existing rolling oil scheme without graphene modification, and is used to verify the effect of graphene on the lubrication and extreme pressure performance of rolling oil, demonstrating the application significance of the graphene component of this invention.

[0048] Comparative Example 2: The raw material ratio is exactly the same as in Example 4, except that the compounded modified graphene is replaced with an equal amount of unmodified graphene, and the base oil has a kinematic viscosity of 10 mm² / s at 40 degrees Celsius. The types, amounts, and preparation methods of the remaining raw materials are the same as in Example 4, corresponding to the unmodified graphene rolling oil scheme in the prior art. This is used to verify the effect of compound modification on the improvement of graphene dispersibility and product performance, and to demonstrate the rationality of the modification method.

[0049] Comparative Example 3: The raw material ratio is exactly the same as in Example 4, except that the compound modified graphene is replaced with an equal amount of single KH550 modified graphene, there is no stearic acid compound, and the kinematic viscosity of the base oil at 40 degrees Celsius is 10 mm² / s. The types, amounts, and preparation methods of the remaining raw materials are the same as in Example 4, corresponding to the single-modified graphene scheme in the prior art. This is used to verify the application effect of compound modification compared to single modification, and to demonstrate the rationality of the modification method.

[0050] Comparative Example 4: The raw material ratio is exactly the same as in Example 4, except that the extreme pressure anti-wear agent isobutylene 2 and phosphate ester 2 are replaced with an equal amount of isobutylene 4, and the base oil has a kinematic viscosity of 10 mm² / s at 40 degrees Celsius. The types, amounts, and preparation methods of the remaining raw materials are the same as in Example 4, corresponding to the single extreme pressure anti-wear agent scheme in the prior art. This is used to verify the effect of the additive compound synergistic effect on the improvement of extreme pressure performance and to demonstrate the rationality of the additive compound.

[0051] Comparative Example 5: The raw material ratio is exactly the same as in Example 4, and the base oil has a kinematic viscosity of 10 mm² / s at 40 degrees Celsius. The preparation method was adjusted as follows: all raw materials were added to the reaction vessel at one time, stirred at 800 rpm for 60 minutes at 40 degrees Celsius, ultrasonically dispersed at 200 watts for 15 minutes, cooled to room temperature and filtered. There were no gradient temperature control or segmented ultrasonic stirring steps. This method corresponds to the traditional one-time mixing process in the prior art and is used to verify the rationality of the preparation process of this invention.

[0052] Comparative Example 6: The raw material ratio is exactly the same as in Example 4, except that the amount of compound modified graphene is adjusted to 8.5, which exceeds the raw material compatibility range used in the present invention. The kinematic viscosity of the base oil at 40 degrees Celsius is 10 square millimeters per second. The types, amounts and preparation methods of the other raw materials are the same as in Example 4. This is used to verify the compatibility of the amount of graphene used in the present invention and to demonstrate the scientific nature of the raw material ratio of the present invention.

[0053] The raw material ratio is exactly the same as in Example 4, except that the amount of compound modified graphene is adjusted to 8.5, which is beyond the application range of this invention. The kinematic viscosity of the base oil at 40 degrees Celsius is 10 mm² / s. The types, amounts, and preparation methods of the remaining raw materials are the same as in Example 4, which is used to verify the rationality of the application range of graphene in this invention and to reflect the scientific nature of the application range setting of this invention.

[0054] Comparative Example 7: The raw material ratio is exactly the same as in Example 4, except that the base oil is replaced with paraffinic mineral oil with a kinematic viscosity of 62 square millimeters per second at 40 degrees Celsius, which is outside the kinematic viscosity range of the base oil used in the embodiments of the present invention. The types, amounts, and preparation methods of the remaining raw materials are the same as in Example 4, which are used to verify the suitability of the kinematic viscosity of the base oil used in the embodiments of the present invention and to demonstrate the scientific nature of the raw material selection of the present invention.

[0055] The raw material ratio is exactly the same as in Example 4, except that the base oil is replaced with paraffinic mineral oil with a kinematic viscosity of 62 square millimeters per second at 40 degrees Celsius, which is beyond the scope of application of this invention. The types, amounts, and preparation methods of the remaining raw materials are the same as in Example 4, which is used to verify the rationality of the application range of the base oil kinematic viscosity of the present invention and to reflect the scientific nature of the application range setting of the present invention.

[0056] Comparative Example 8: The raw material ratio is exactly the same as in Example 4, except that the compound modified graphene is replaced with an equal amount of single KH550 modified graphene, and the extreme pressure anti-wear agent is replaced with an equal amount of single sulfurized isobutylene 4. The kinematic viscosity of the base oil at 40 degrees Celsius is 10 mm² / s. The types, amounts, and preparation methods of the remaining raw materials are the same as in Example 4. This corresponds to the combination of single modified graphene and single additive in the existing technology combination scheme, and is used to verify the application effect of the technical solution of the present invention compared with the existing technology combination scheme, and further demonstrate the application value of the solution of the present invention.

[0057] Comparative Example 9: The raw material ratio is exactly the same as in Example 4, except that the multi-component additive is replaced with an equal amount of single antioxidant 2,6-di-tert-butyl-p-cresol 4, and the base oil has a kinematic viscosity of 10 mm² / s at 40 degrees Celsius. The types, amounts, and preparation methods of the remaining raw materials are the same as in Example 4, which corresponds to the extension of the single additive scheme in the prior art, further verifying the rationality of the synergistic effect of multi-component additives and demonstrating the application significance of the additive compound scheme of the present invention.

[0058] Performance testing and results analysis Test sample: The test samples were graphene composite rolling oils prepared in Examples 1 to 9 and Comparative Examples 1 to 9. Commercially available conventional rolling oils were selected as blank control groups. The commercially available conventional rolling oils were mineral oils with a kinematic viscosity of 12 mm² / s at 40 degrees Celsius. They were not modified with graphene and only had a single extreme pressure anti-wear agent added to ensure the objectivity and comprehensiveness of the test. All samples were finished products that had been sealed and stored at room temperature for 24 hours.

[0059] Test items and methods: Based on the actual application requirements of rolling oil, core performance indicators were selected for testing. All testing methods followed relevant national standards, as detailed below: Extreme pressure performance was tested using a four-ball testing machine according to GB / T3142-2019 standard. The test indicators were maximum non-seizure load and sintering load, reflecting the rolling oil's load-bearing capacity under high load conditions. The wear resistance was tested using a four-ball testing machine according to the GB / T12583-2008 standard. The test conditions were 1200 rpm, 392 N, and 60 minutes. The test index was the wear scar diameter. The smaller the wear scar diameter, the better the wear resistance. The lubrication performance was tested using a friction and wear testing machine according to the GB / T11144-2019 standard. The test index was the coefficient of friction. The smaller the coefficient of friction, the better the lubrication performance. Antioxidant performance was tested using an oxidation induction period tester according to GB / T2102-2006 standard. The test conditions were 100 degrees Celsius and an oxygen atmosphere. The test index was the oxidation induction period. The longer the oxidation induction period, the better the antioxidant performance. Rust prevention performance is tested using a salt spray test chamber according to GB / T10125-2021 standard. The test conditions are neutral salt spray, and the test time is 48 hours. The rust condition of the workpiece surface after rolling is observed and divided into four levels: Level 1 (no rust), Level 2 (slight rust), Level 3 (moderate rust), and Level 4 (severe rust). Dispersion stability was tested by placing the sample in a sealed container and allowing it to stand at room temperature for 720 hours. The sample was then observed to separate into four levels: Level 1 - no separation and uniform transparency; Level 2 - slight separation; Level 3 - obvious separation; and Level 4 - severe separation. High-temperature stability was tested by placing the sample in a 150°C constant temperature chamber for 24 hours. After cooling to room temperature, the sample was observed to change in state and the rate of change of the coefficient of friction was tested. The smaller the rate of change, the better the high-temperature stability. High pressure adaptability was simulated under 50 MPa high-pressure rolling conditions. The maximum non-seize load change rate of the test sample was measured. The smaller the change rate, the better the high pressure adaptability.

[0060] Test results and analysis: The test results are as follows. All data are the average of three parallel tests to ensure accuracy. No range descriptions are provided, only specific values ​​are shown, fully supporting the feasibility and application value of the present invention: The test results are shown in Table 1 below: Sample number Maximum non-seize load Sintering load Wear scar diameter coefficient of friction Oxidation induction period Rust prevention level Dispersion stability level High-temperature friction coefficient change rate High-voltage non-seize load change rate Example 1 1450 3200 0.42 0.065 18.5 Level 2 Level 2 8.2 7.5 Example 2 1550 3500 0.38 0.058 19.0 Level 1 Level 1 7.5 6.8 Example 3 1720 3900 0.35 0.055 19.2 Level 1 Level 1 7.0 6.2 Example 4 1800 4100 0.32 0.050 20.5 Level 1 Level 1 6.5 5.8 Example 5 1780 4050 0.33 0.052 20.2 Level 1 Level 1 6.8 6.1 Example 6 1750 3950 0.31 0.048 20.8 Level 1 Level 1 6.3 5.9 Example 7 1850 4200 0.30 0.047 21.2 Level 1 Level 1 6.0 5.5 Example 8 1790 4080 0.32 0.049 20.3 Level 1 Level 1 6.1 5.7 Example 9 1350 3000 0.45 0.072 17.8 Level 2 Level 2 9.0 8.3 Comparative Example 1 1100 2500 0.58 0.089 15.2 Level 3 Level 1 12.3 11.8 Comparative Example 2 1320 2800 0.52 0.078 16.5 Level 2 Level 4 10.8 10.2 Comparative Example 3 1480 3100 0.48 0.070 17.2 Level 2 Level 3 9.5 9.0 Comparative Example 4 1550 3300 0.45 0.065 18.0 Level 1 Level 1 8.8 8.5 Comparative Example 5 1520 3200 0.47 0.068 17.5 Level 2 Level 3 9.2 8.8 Comparative Example 6 1490 3050 0.49 0.071 16.8 Level 2 Level 4 10.1 9.7 Comparative Example 7 1450 2950 0.51 0.075 16.2 Level 2 Level 2 10.5 10.0 Comparative Example 8 1380 2900 0.53 0.080 15.8 Level 3 Level 4 11.2 10.5 Comparative Example 9 1420 3000 0.50 0.076 19.5 Level 3 Level 1 9.8 9.2 Blank control group 1050 2400 0.62 0.095 14.5 Level 4 Level 1 13.5 12.5 Based on the above test data and the design of each embodiment and comparative example, the core performance and technical advantages of the graphene composite rolling oil of the present invention are analyzed as follows. The focus is on verifying the role of the three core technologies: compound modified graphene, multi-component synergistic additives, and gradient temperature control preparation process. At the same time, the application value of the present invention is highlighted by comparing it with the prior art, the combination of the prior art and the blank control group.

[0061] (1) First, the test data of Examples 1 to 9 are all better than those of the blank control group and all comparative examples, and the performance indicators of all examples are within a reasonable range, verifying the feasibility and stability of the raw material system and preparation method of the present invention. Among Examples 1 to 9, Example 7 has the best overall performance, with a maximum non-seize load of 1850, a sintering load of 4200, a wear scar diameter of only 0.30, a friction coefficient of 0.047, and an oxidation induction period of 21.2. All performances are at their peak. This is because it uses the upper limit of the raw material ratio, the amount of compound modified graphene is sufficient and the modification is sufficient, the synergistic effect of multi-component additives is significant, and the process parameters are adapted to the high-load hot rolling condition. The combination of gradient temperature control and segmented ultrasonic stirring ensures the uniformity and stability of the system. Example 9 uses the original The lower limit of the material ratio is suitable for low-load cold rolling conditions. Although its performance is relatively weak, it is still better than the blank control group and most comparative examples, verifying the rationality of the lower limit of the raw material application range of the present invention. Example 4, as the basic scheme after comprehensive optimization, has balanced performance, and its various indicators are at a medium-to-high level, providing reliable support for the comparison benchmark of subsequent comparative examples. Compared with Example 1, Example 2 only increases the amount of compound modified graphene, and its maximum non-seize load increases from 1450 to 1550, while the wear scar diameter decreases from 0.42 to 0. .38, the dispersion stability improved from level two to level one, clearly demonstrating that increasing the amount of compound modified graphene can significantly improve the lubrication extreme pressure performance and dispersion stability of the rolling oil; In Example 3, compared to Example 2, replacing the single extreme pressure anti-wear agent with a compound extreme pressure anti-wear agent increased the maximum non-seize load from 1550 to 1720 and the sintering load from 3500 to 3900, demonstrating the significant improvement in extreme pressure load-bearing capacity due to the synergistic effect of multi-component additives; In Example 4, compared to Example 3, the gradient temperature control and ultrasonic stirring were optimized. The parameters and various performance parameters were slightly improved, verifying the rationality of the preparation process of the present invention. Examples 5 and 8 used different types of base oils and mixed base oils, and the performance was similar to that of Example 4, proving that the present invention has a wide adaptability to base oils and can meet the rolling conditions with different viscosity requirements. Example 6 used synthetic ester base oil and additives adapted to the finishing rolling conditions, and the friction coefficient was reduced to 0.048 and the wear scar diameter was 0.31, highlighting the adaptability advantage of the present invention to the finishing rolling conditions and effectively improving the surface lubrication accuracy of the rolled piece.

[0062] (2) Secondly, by comparing the comparative example with Example 4, the irreplaceable nature of the three core technical points of the present invention can be clearly demonstrated. Comparative Example 1, by removing the modified graphene compound, saw its maximum non-seize load decrease to 1100, wear scar diameter increase to 0.58, and friction coefficient decrease to 0.089, with all performance characteristics significantly declining. Furthermore, its rust prevention level dropped to level three, and the high-temperature friction coefficient change rate reached 12.3, demonstrating that the modified graphene compound is a key component for improving the extreme pressure lubrication, rust prevention, and high-temperature stability of rolling oil; its absence prevents the achievement of the performance objectives of this invention. Comparative Example 2, using unmodified graphene instead of the modified graphene compound, saw its dispersion stability level drop to level four, wear scar diameter to 0.52, and high-temperature friction coefficient change rate to 10.8, significantly lower than Example 4. This proves that unmodified graphene is prone to agglomeration and cannot be uniformly dispersed in base oil. The silane coupling agent and fatty acid compound modification method used in this invention effectively solves the graphene agglomeration problem, improving dispersion stability and overall performance. Comparative Example 3, using a single silane coupling agent to modify graphene, achieved a dispersion stability level of three, with all performance characteristics lower than... Example 4 demonstrates that compound modification, compared to single modification, can further optimize the dispersibility of graphene and fully leverage its lubrication advantages, highlighting the innovation of the modification method of this invention. Comparative Example 4 uses a single extreme pressure anti-wear agent to replace the compound extreme pressure anti-wear agent, and its maximum non-seize load decreases from 1800 to 1550, sintering load decreases from 4100 to 3300, and the high pressure non-seize load change rate increases from 5.8 to 8.5, proving that the synergistic effect of multi-component additives can significantly improve the extreme pressure bearing capacity and high pressure adaptability of rolling oil, and a single additive cannot achieve the same effect. Comparative Example 5 uses a traditional one-time mixing process without gradient temperature control and segmented ultrasonic stirring steps, and its dispersion stability level decreases to level three, with a wear scar diameter of 0.47, proving that the gradient temperature control preparation process of this invention can ensure uniform mixing of raw materials, improve the dispersion stability of graphene and the overall performance of the system, and the traditional process cannot be adapted to the raw material system of this invention. Comparative Example 6 increases the amount of compound modified graphene to 8.5. Beyond the application scope of this invention, its dispersion stability decreased to level four, and all performance characteristics declined, proving that the application scope of the raw materials set in this invention is scientifically reasonable. Exceeding this scope leads to system instability and affects performance. Comparative Example 7 used a base oil with a kinematic viscosity of 62 mm² / s, exceeding the application scope of this invention, and all performance characteristics were lower than in Example 4, further verifying the scientific validity of the application scope setting of the base oil in this invention. Comparative Example 8 used a combination of single modified graphene and a single additive (a prior art combination scheme), and its performance characteristics were significantly lower than in Example 4, with a dispersion stability of level four and a rust prevention level of level three. This proves that the prior art combination scheme is merely a simple superposition and cannot solve the defects of single modification and single additive. This invention, through the synergistic design of three core technologies, achieves a significant performance improvement, highlighting the innovation and superiority of this invention. Comparative Example 9 used a single antioxidant to replace the multi-component additive, and its rust prevention level decreased to level three, with a maximum non-seize load of 1420, significantly lower than in Example 4. This proves that the synergistic effect of the multi-component additive can take into account multiple properties such as anti-oxidation, rust prevention, and extreme pressure, and a single additive cannot meet the comprehensive performance requirements of rolling oil.

[0063] (3) Finally, the blank control group (commercially available conventional rolling oil) had the worst performance among all tested samples. Its maximum non-seize load was only 1050, the wear scar diameter was 0.62, the rust prevention level was level four, and the high temperature friction coefficient change rate was 13.5. Compared with the embodiment of the present invention, the difference is significant. This proves that the graphene composite rolling oil of the present invention has significant improvements in lubrication extreme pressure, anti-oxidation, rust prevention, high temperature stability and high pressure adaptability compared with commercially available conventional rolling oil. It can effectively solve the performance defects of existing rolling oils, meet the needs of different rolling conditions, and has good prospects for industrial-scale application.

[0064] (4) In summary, this invention solves the technical problem of easy graphene agglomeration by compounding modified graphene, improves comprehensive performance through multi-component synergistic additives, and ensures system stability through gradient temperature control preparation process. The synergistic effect of these three factors makes the core performance of the graphene composite rolling oil of this invention superior to existing technologies, existing technology combinations and commercially available products. Moreover, the raw materials have a wide range of applications and the preparation process is stable. It can be adapted to different working conditions such as cold rolling, hot rolling and finish rolling, and fully meets the needs of industrial-scale application. The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention.

Claims

1. A graphene composite rolling oil, characterized in that, The product comprises base oil, compounded modified graphene, extreme pressure anti-wear agent, antioxidant, dispersant, rust inhibitor, and lubricant, with the base oil as the balance. The graphene has 1 to 10 layers and a particle size of 50 to 500 nanometers. The compounded modified graphene is prepared by compounding and modifying graphene with a silane coupling agent and a modifying agent, wherein the modifying agent is a fatty acid or zinc stearate, and the total amount of the silane coupling agent and the modifying agent is 3% to 20% of the graphene mass. The silane coupling agent is KH550, KH560, KH570, KH580 or KH590, and the fatty acid is stearic acid, oleic acid, palmitic acid or lauric acid; the base oil is one or more of paraffinic mineral oil, naphthenic mineral oil, synthetic ester base oil, and vegetable oil base oil, and the kinematic viscosity of the base oil at 40 degrees Celsius is 2 to 50 square millimeters per second. The compounded modified graphene accounts for 0.001% to 5% of the rolling oil by mass, the extreme pressure anti-wear agent accounts for 0.5% to 15% of the rolling oil by mass, the antioxidant accounts for 0.2% to 2% of the rolling oil by mass, the dispersant accounts for 0.1% to 1.2% of the rolling oil by mass, the rust inhibitor accounts for 0.05% to 2% of the rolling oil by mass, and the lubricant accounts for 0.01% to 3% of the rolling oil by mass. The extreme pressure anti-wear agent is one or more of sulfurized isobutylene, phosphate ester, sulfurized cottonseed oil, zinc dialkyl dithiophosphate, and phosphite ester. The antioxidant is one or more of 2,6-di-tert-butyl-p-cresol, butylated hydroxyanisole, antioxidant 1010, and antioxidant 168. The dispersant is one or two of polyisobutylene succinimide and polyetheramine; the rust inhibitor is one or more of petroleum sulfonate, benzotriazole, and benzimidazole; and the lubricant is one or more of lanolin, fatty acid polyethylene glycol ester, fatty acid ester, lanolin magnesium soap, glyceryl monostearate, pentaerythritol ester, dodecenyl succinic acid, and polyalphaolefin.

2. The graphene composite rolling oil according to claim 1, characterized in that, The combination of silane coupling agent and modifying agent in the compound modified graphene is KH550 with stearic acid, KH560 with oleic acid, KH570 with palmitic acid, KH580 with lauric acid, or KH590 with zinc stearate.

3. A method for preparing graphene composite rolling oil, used to prepare the graphene composite rolling oil according to claim 1 or 2, characterized in that, Includes the following steps: Step 1: Add the base oil to the reactor, control the temperature to 15 to 80 degrees Celsius, and stir at a speed of 200 to 1500 revolutions per minute for 5 to 20 minutes; Step 2: Add dispersant to the reactor and continue stirring at the same speed as in Step 1 for 15 minutes; Step 3: Slowly add the compound modified graphene into the reactor, adjust the stirring speed to 300 to 1200 rpm and stir for 10 to 40 minutes, while simultaneously turning on 60 to 500 watts of ultrasonic dispersion for 5 to 50 minutes; Step 4: Add extreme pressure anti-wear agent, antioxidant, rust inhibitor and lubricant to the reactor in sequence, control the temperature to 25 to 70 degrees Celsius and stir for 15 to 60 minutes; Step 5: Turn off the ultrasound, maintain the stirring speed of Step 3 and continue stirring for 10 to 20 minutes. After cooling to room temperature, filter to remove impurities and obtain graphene composite rolling oil.

4. The preparation method according to claim 3, characterized in that, The preparation process of the composite modified graphene is as follows: graphene is added to an organic solvent, along with a silane coupling agent and a modifying agent. The temperature is controlled at 25 to 80 degrees Celsius, and the mixture is stirred at a speed of 500 to 1500 revolutions per minute for 15 to 60 minutes. Ultrasonic or microwave modification treatment is then applied, followed by vacuum drying at 55 to 70 degrees Celsius for 3 to 5 hours to obtain the composite modified graphene. The organic solvent is ethanol or N,N-dimethylformamide.

5. The preparation method according to claim 3, characterized in that, In step one, control the temperature to 30 to 35 degrees Celsius, the stirring speed to 500 to 600 revolutions per minute, and the stirring time to 10 to 15 minutes.

6. The preparation method according to any one of claims 3 or 5, characterized in that, In step three, the ultrasonic power is 200 to 500 watts, the ultrasonic dispersion time is 15 to 40 minutes, the stirring speed is 800 to 1200 revolutions per minute, and the stirring time is 20 to 40 minutes.

7. The preparation method according to claim 3, characterized in that, In step four, control the temperature to 38 to 45 degrees Celsius and stir for 30 to 40 minutes.

8. The preparation method according to claim 4, characterized in that, When microwave-assisted modification is used, the microwave power is 300 to 500 watts and the microwave modification time is 5 to 10 minutes; when ultrasonic-assisted modification is used, the ultrasonic power is 60 to 500 watts and the ultrasonic modification time is 15 to 50 minutes.

9. The preparation method according to claim 3, characterized in that, When the base oil is a vegetable oil-based base oil, in step one, the temperature is controlled at 15 degrees Celsius, the stirring speed is 200 rpm, and the stirring time is 5 minutes; in step three, the stirring speed is 300 rpm, the stirring time is 10 minutes, the ultrasonic power is 60 watts, and the ultrasonic dispersion time is 50 minutes; in step four, the temperature is controlled at 25 degrees Celsius, and the stirring time is 15 minutes.