Carbon-dot-containing extreme pressure antifriction and antiwear compound additive and application thereof
By compounding carbon dots with organometallic additives, a high-strength hybrid friction protection film is formed, which solves the performance deficiencies of carbon dots and organometallic additives respectively, achieves the stability of friction coefficient and improves extreme pressure performance, and is suitable for the lubricant field.
Patent Information
- Application Number
- CN202510995287.4
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-18
- Publication Date
- 2025-09-23
AI Technical Summary
The friction coefficient of existing carbon dots increases briefly at the initial stage of friction and the extreme pressure effect is insufficient. In addition, the protective film strength of the organic metal additive is insufficient, resulting in fluctuations in the friction coefficient. At the same time, the amount of organic metal additives needs to be reduced to meet environmental protection requirements.
Carbon dots are compounded with organic metal additives such as molybdenum dialkyldithiocarbamate (MoDTC), zinc dialkyldithiocarbamate (ZnDTC), and zinc dialkyldithiophosphate (ZDDP) to form a high-strength hybrid friction protective film, which is then prepared as a lubricant by triple-roll milling.
The stability of the friction coefficient and the improvement of extreme pressure performance are achieved, the use of organic metal additives is reduced, and the lubrication performance is maintained or improved.
Smart Images
Figure CN120682857A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of lubricating additives, in particular to a carbon point-containing extreme pressure, friction-reducing and anti-wear compound additive and application thereof. Background Art
[0002] Carbon dots are zero-dimensional fluorescent carbon nanomaterials with a quasi-spherical structure less than 10 nm in size. They have been extensively studied in catalysis, bioimaging, drug delivery, batteries, and other fields. As a nanomaterial, they perform fundamental functions in the field of lubrication, such as rolling, patching, and polishing, and can repair minor damage to the surfaces of friction pairs. Furthermore, due to their small size and rich surface groups, carbon dots are more easily absorbed and adsorbed at the friction interface, forming a protective carbon film in the friction area to protect the friction pair. However, the film formation rate of carbon dots is relatively slow, resulting in a brief increase in the friction coefficient in the initial stage of friction and insufficient extreme pressure effect.
[0003] Organometallic additives contain organic elements such as nitrogen, sulfur, and phosphorus, along with metallic elements. They rapidly react tribochemically with the metal substrate, forming a protective film that protects the friction pair. These additives are low-cost and highly effective, making them a key component of grease additive packages. However, this protective film is weak and easily damaged, leading to fluctuations in the friction coefficient. Furthermore, due to environmental protection requirements, the use of these sulfur-containing additives should be reduced.
[0004] However, there are currently no reports on the combined use of carbon dots and organometallic additives. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a carbon point-containing extreme pressure, friction-reducing and anti-wear compound additive that achieves synergistic lubrication and reduces the amount of organic metal additives used.
[0006] Another technical problem to be solved by the present invention is to provide an application of an extreme pressure, friction-reducing and anti-wear compound additive containing carbon dots.
[0007] To solve the above problems, the present invention discloses a carbon dot-containing extreme pressure, friction-reducing and anti-wear compound additive, characterized in that the compound additive is composed of carbon dots (CDs) and an organic metal additive; the organic metal additive is one of molybdenum dialkyldithiocarbamate (MoDTC), zinc dialkyldithiocarbamate (ZnDTC), and zinc dialkyldithiophosphate (ZDDP).
[0008] The carbon dots were prepared according to the following method: 5 g of anhydrous citric acid and 1 g of tetrabutylammonium phosphate were added to a container and maintained at 200°C for 0.5 h; after stopping heating, 50 mL of deionized water was added to the reaction system and ultrasonically dispersed for 20 min to obtain a mixed solution; ethyl acetate was added to the mixed solution with an equal volume of deionized water, and an organic phase was obtained through extraction. The solvent in the organic phase was removed by rotary evaporation to obtain a crude product; and the crude product was vacuum dried at 70°C for 24 h.
[0009] The application of the carbon dot-containing extreme pressure, friction-reducing and anti-wear compound additive as described above is characterized in that the compound additive is used to prepare a lubricant, which is composed of 0.5% to 1% carbon dots (CDs) by mass, 0.5% to 1.5% organic metal additives by mass, and the balance being lithium-based grease (LG).
[0010] The lubricant is prepared according to the following method: first, weighing according to the ratio; then adding carbon dots to 1 / 2 of the total mass of lithium-based grease, grinding it with a three-roll mill to obtain a grease composition containing carbon dots, recorded as grease composition A; secondly, adding an organic metal additive to the remaining lithium-based grease, grinding it with a three-roll mill to obtain a grease composition containing an organic metal additive, recorded as grease composition B; finally, grease composition A and grease composition B are mixed and ground with a three-roll mill to obtain the lubricant.
[0011] Compared with the prior art, the present invention has the following advantages: 1. This invention combines carbon dots with organometallic additives. The carbon dots form a carbon protective film, while the organometallic additive forms a film more quickly. The resulting hybrid friction protective film has high strength, a stable friction coefficient, and significantly improved extreme pressure performance. This also alleviates the problem of a temporary increase in friction coefficient when carbon dots are used as an additive, reducing the amount of organometallic additive used.
[0012] 2. The compounding of carbon dots and organometallic additives in the present invention combines the advantages of both materials, makes up for their performance shortcomings, exerts a synergistic lubricating effect, and expands the practical application of carbon dots as additives in the field of lubrication engineering. BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The specific embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.
[0014] Figure 1 This is a real-time friction coefficient diagram of the lubricant containing CDs, MoDTC and extreme pressure friction reducing and anti-wear compound additives of the present invention.
[0015] Figure 2 This is a real-time friction coefficient diagram of the lubricant containing CDs, ZnDTC and extreme pressure friction reducing and anti-wear compound additives of the present invention.
[0016] Figure 3 This is a real-time friction coefficient diagram of the lubricant containing CDs, ZDDP and extreme pressure friction reducing and anti-wear compound additives of the present invention. DETAILED DESCRIPTION
[0017] A carbon dot-containing extreme pressure, friction-reducing and anti-wear compound additive, the compound additive being composed of carbon dots (CDs) and an organic metal additive; the organic metal additive being one of molybdenum dialkyldithiocarbamate (MoDTC), zinc dialkyldithiocarbamate (ZnDTC), and zinc dialkyldithiophosphate (ZDDP).
[0018] The carbon dots were prepared as follows: 5 g of anhydrous citric acid and 1 g of tetrabutylammonium phosphate were added to a container and maintained at 200°C for 0.5 h; after stopping heating, 50 mL of deionized water was added to the reaction system and ultrasonically dispersed for 20 min to obtain a mixed solution; an equal volume of ethyl acetate was added to the mixed solution, and an organic phase was obtained by extraction. The solvent in the organic phase was removed by rotary evaporation to obtain a crude product; and the crude product was vacuum dried at 70°C for 24 h.
[0019] The invention discloses an application of an extreme pressure, friction-reducing and anti-wear compound additive containing carbon dots. The compound additive is used to prepare a lubricant. The lubricant is composed of 0.5% to 1% by mass of carbon dots (CDs), 0.5% to 1.5% by mass of an organic metal additive, and the balance being lithium-based grease (LG).
[0020] The lubricant is prepared according to the following method: first, the mixture is weighed according to the ratio; then, carbon dots are added to 1 / 2 of the total mass of lithium-based grease, and the mixture is ground by a triple-roll mill to obtain a grease composition containing carbon dots, which is recorded as grease composition A; secondly, an organometallic additive is added to the remaining lithium-based grease, and the mixture is ground by a triple-roll mill to obtain a grease composition containing an organometallic additive, which is recorded as grease composition B; finally, grease composition A and grease composition B are mixed and ground by a triple-roll mill to obtain the lubricant.
[0021] Example 1 The lubricant consisted of 1 g CDs, 0.5 g MoDTC, and 98.5 g LG.
[0022] The preparation method is as follows: 1g of CDs is added to 49.25g of LG, and the mixture is ground by a triple-roll mill to obtain a grease composition containing carbon dots, which is recorded as grease composition A; then 0.5g of MoDTC is added to 49.25g of LG, and the mixture is ground by a triple-roll mill to obtain a grease composition containing an organic metal additive, which is recorded as grease composition B; finally, grease composition A and grease composition B are mixed and ground by a triple-roll mill to obtain the product.
[0023] Example 2 The lubricant consisted of 1 g CDs, 0.5 g ZnDTC, and 98.5 g LG.
[0024] The preparation method is as follows: 1g of CDs is added to 49.25g of LG, and the mixture is ground by a triple-roll mill to obtain a grease composition containing carbon dots, which is recorded as grease composition A; secondly, 0.5g of ZnDTC is added to 49.25g of LG, and the mixture is ground by a triple-roll mill to obtain a grease composition containing an organic metal additive, which is recorded as grease composition B; finally, grease composition A and grease composition B are mixed and ground by a triple-roll mill to obtain the product.
[0025] Example 3 The lubricant consisted of 1 g CDs, 0.5 g ZDDP, and 98.5 g LG.
[0026] The preparation method is as follows: 1g of CDs is added to 49.25g of LG, and the mixture is ground by a triple-roll mill to obtain a grease composition containing carbon dots, which is recorded as grease composition A; secondly, 0.5g of ZDDP is added to 49.25g of LG, and the mixture is ground by a triple-roll mill to obtain a grease composition containing an organic metal additive, which is recorded as grease composition B; finally, grease composition A and grease composition B are mixed and ground by a triple-roll mill to obtain the product.
[0027] Comparative Example 1 The lubricant consisted of 0.5 g MoDTC and 99.5 g LG.
[0028] The preparation method is as follows: 0.5g MoDTC and 99.5g LG are mixed and ground with a three-roll mill.
[0029] Comparative Example 2 The lubricant consisted of 0.5 g ZnDTC and 99.5 g LG.
[0030] The preparation method is as follows: 0.5g ZnDTC and 99.5g LG are mixed and ground with a three-roll mill.
[0031] Comparative Example 3 The lubricant consisted of 0.5 g ZDDP and 99.5 g LG.
[0032] The preparation method is as follows: 0.5 g ZDDP and 99.5 g LG are mixed and ground with a three-roll mill.
[0033] Comparative Example 4 The lubricant consisted of 1.5 g MoDTC and 98.5 g LG.
[0034] The preparation method is as follows: 1.5g MoDTC and 98.5g LG are mixed and ground with a three-roll mill.
[0035] Comparative Example 5 The lubricant consisted of 1.5 g ZnDTC and 98.5 g LG.
[0036] The preparation method is as follows: 1.5g ZnDTC and 98.5g LG are mixed and ground with a three-roll mill.
[0037] Comparative Example 6 The lubricant consisted of 1.5 g ZDDP and 98.5 g LG.
[0038] The preparation method is as follows: 1.5 g ZDDP and 98.5 g LG are mixed and ground with a three-roll mill.
[0039] Comparative Example 7 The lubricant consisted of 1 g of CDs and 99 g of LG.
[0040] The preparation method is as follows: 1g CDs and 99g LG are mixed and ground with a three-roll mill.
[0041] The lubricants described in Examples 1 to 3 and Comparative Examples 1 to 7 were subjected to performance tests: The lubricant's lubrication performance was evaluated on a four-ball tribometer under a load of 392 N, a temperature of 75°C, a rotational speed of 1200 r / min, and a test time of 60 min. GCr15 steel balls were used. The extreme pressure performance (PB value) of the lubricant was also evaluated on a four-ball extreme pressure tester. GCr15 steel balls were also used. After the friction test, the wear spot diameter was measured using an optical microscope.
[0042] The results are shown in Table 1 and Figures 1-3 shown.
[0043] Table 1 Wear spot diameter and PB value of grease compositions containing CDs, organic metal additives and extreme pressure friction reducing and anti-wear compound additives From Table 1 and Figures 1-3 It can be seen that the addition of the compound additive demonstrates a superior lubrication effect compared to either additive alone, stabilizing the friction coefficient, reducing the wear spot diameter, and increasing the PB value. Furthermore, compared to increasing the content of the organometallic additive, the compound additive can still maintain or even improve lubrication performance.
Claims
1. A carbon-containing extreme pressure, friction-reducing and anti-wear compound additive, characterized by: The compound additive is composed of carbon dots and an organic metal additive; the organic metal additive is one of dialkyl dithiocarbamate molybdenum, dialkyl dithiocarbamate zinc, and dialkyl dithiophosphate zinc.
2. The carbon-containing extreme pressure, friction-reducing and anti-wear compound additive according to claim 1, characterized in that: The carbon dots were prepared by the following method: 5 g of anhydrous citric acid and 1 g of tetrabutylammonium phosphate were added to a container and maintained at 200°C for 0.5 h; after stopping heating, 50 mL of deionized water was added to the reaction system and ultrasonically dispersed for 20 min to obtain a mixed solution; an equal volume of ethyl acetate was added to the mixed solution as that of the deionized water, and an organic phase was obtained by extraction. The solvent in the organic phase was removed by rotary evaporation to obtain a crude product; and the crude product was vacuum dried at 70°C for 24 h.
3. Use of a carbon-containing extreme pressure, friction-reducing and anti-wear compound additive as claimed in claim 1 or 2, characterized in that: The compound additive is used to prepare a lubricant, which consists of 0.5% to 1% by mass of carbon dots, 0.5% to 1.5% by mass of an organic metal additive, and the balance being lithium-based grease.
4. The use of a carbon-dot extreme pressure, friction-reducing and anti-wear compound additive as claimed in claim 3, characterized in that: The lubricant is prepared according to the following method: first, weighing according to the ratio; then adding carbon dots to 1 / 2 of the total mass of lithium-based grease, grinding it with a three-roll mill to obtain a grease composition containing carbon dots, recorded as grease composition A; secondly, adding an organic metal additive to the remaining lithium-based grease, grinding it with a three-roll mill to obtain a grease composition containing an organic metal additive, recorded as grease composition B; finally, grease composition A and grease composition B are mixed and ground with a three-roll mill to obtain the lubricant.