Lubricating grease as well as preparation method and application thereof
By using a specific ratio of grease composition and modified nanomaterials, the problems of unstable friction torque and fretting wear in shock absorber plane bearing grease have been solved, improving the stability and low-temperature performance of the grease, extending its service life and reducing production costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- ZHEJIANG DERUNBAO NEW MATERIALS CO LTD
- Filing Date
- 2026-02-03
- Publication Date
- 2026-05-12
AI Technical Summary
Existing greases used in shock absorber bearings exhibit excessive or unstable frictional torque, insufficient resistance to fretting wear, poor environmental tolerance, short lifespan, and poor performance balance. They are unable to provide low and stable frictional torque over a wide temperature range, resulting in poor steering feel and abnormal noises.
By using a specific ratio of base oil, thickener, anti-wear and friction reducing agent, antioxidant and rust inhibitor, and compounding modified silicone oil and metal soap fiber network, a highly stable and highly elastic grease is formed. Combined with modified boron nitride nanotubes and specific antioxidants, the anti-wear and friction reducing performance and low-temperature performance are improved.
It achieves high stability, anti-wear and friction-reducing properties, and high and low temperature performance of the grease, reduces low-temperature torque, improves compatibility with plastic materials, extends service life, and reduces abnormal noise and wear.
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This invention belongs to the field of lubricants, specifically relating to a lubricating grease, its preparation method and application, and more particularly to a lubricating grease with good anti-wear and friction-reducing properties, its preparation method and application. Background Technology
[0002] The thrust bearing of an automotive shock absorber is a key component connecting the vehicle body and the suspension spring / shock absorber assembly, located at the top of the shock absorber. Its main function is to allow the shock absorber piston rod to oscillate and rotate at low speeds and small angles during steering, while bearing the vehicle's axial load. The lubrication condition of this component directly determines the vehicle's steering feel, self-centering performance, NVH (noise, vibration, and harshness) level, and overall chassis quality. Currently, this part is commonly lubricated using general-purpose lithium-based grease, calcium-based grease, or some polyurea-based greases. However, due to the special and harsh operating conditions, existing lubrication solutions have the following prominent technical defects: excessive or unstable frictional torque, leading to poor steering feel; insufficient resistance to fretting wear, easily causing abnormal noises and clearances; poor environmental tolerance and short lifespan; and poor performance balance. An ideal grease should provide low and stable frictional torque over a wide temperature range, fundamentally inhibiting fretting wear to eliminate abnormal noises, and possessing excellent water resistance, rust prevention, and long-term stability, thereby improving the overall vehicle driving quality, reliability, and service life.
[0003] CN118879381A discloses a bearing grease composition and its preparation method, comprising the following components by weight percentage: 60-72 parts of fluorinated base oil, 24-30 parts of thickener, and 4-5 parts of modified filler additive. The grease utilizes zirconium oxide-modified graphene nanoparticles to promote the formation of a transfer film, improving boundary lubrication in the friction system and enhancing the grease's wear resistance. Zirconium ions, through coordination, promote the entry and attachment of heterocyclic compounds into the graphene layered structure. The heterocyclic compounds, grafted with eugenol groups containing oxygen-containing radicals and combined with TBA fluorine elements, improve oil solubility, significantly enhancing the grease's mechanical properties, thermal stability, and wear resistance.
[0004] CN119391473A discloses an anti-friction noise lubricating agent and its preparation method, which is made from the following raw materials in parts by weight: 10-20 parts paraffin wax, 5-10 parts emulsifier, 30-35 parts deionized water, 10-15 parts methyl silicone oil emulsion, 50 parts deionized water, 1-3 parts polytetrafluoroethylene, 1-2 parts hexagonal boron nitride, 0.1-0.5 parts silicon dioxide, 0.5 parts preservative, 0.5 parts stabilizer, 0.5 parts antioxidant, 1 part dispersant, and 0.5 parts wetting agent. This invention uses paraffin wax to provide adhesion and also acts as a barrier and lubricant. Emulsifiers, methyl silicone oil emulsions, and deionized water are additives that transform solid paraffin wax into a paste or liquid. Polytetrafluoroethylene, hexagonal boron nitride, and silicon dioxide enhance the lubrication effect of the finished reagent. Preservatives, antioxidants, and stabilizers provide protection against corrosion, oxidation, and discoloration. Dispersants and wetting agents can disperse powdered substances. This finished reagent is suitable for use in areas where automotive door panels, dashboard surfaces, painted parts, and electroplated parts come into contact with each other, providing noise reduction through barrier and lubrication.
[0005] As the industry develops, the requirements for lubricating greases in shock absorber bearings are becoming increasingly stringent. Therefore, providing a lubricating grease with excellent anti-wear and friction-reducing properties has become an urgent problem to be solved. Summary of the Invention
[0006] To address the shortcomings of existing technologies, the present invention aims to provide a lubricating grease, its preparation method, and its application, particularly a lubricating grease with excellent anti-wear and friction-reducing properties, its preparation method, and its application. The lubricating grease provided by the present invention exhibits good stability, excellent anti-wear and friction-reducing properties, superior high and low temperature performance, and good compatibility with plastic materials.
[0007] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides a lubricating grease comprising, by weight, 65-85 parts base oil, 8-15 parts thickener, 5-15 parts anti-wear and friction reducing agent, 0.5-5 parts antioxidant, and 0.5-5 parts rust inhibitor.
[0008] The base oil is at least one of dimethyl silicone oil and modified silicone oil.
[0009] The base oil can be in quantities of 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, or 85 parts, etc.; the thickener can be in quantities of 8, 9, 10, 11, 12, 13, 14, or 15 parts, etc.; and the anti-wear and friction-reducing agent can be in quantities of 5, 6, 7, 8, 9, 10, 11, 12, 13, 1... The number of parts for antioxidants can be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5, etc., and the number of parts for rust inhibitors can be 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or 5, etc., but is not limited to the values listed above. Other unlisted values within the above range are also applicable.
[0010] The greases with the above-mentioned specific components have good stability, excellent anti-wear and friction-reducing properties, excellent high and low temperature performance, and good compatibility with plastic materials.
[0011] Preferably, the grease comprises, by weight, 70-80 parts base oil, 10-13 parts thickener, 8-12 parts anti-wear and friction reducing agent, 2-4 parts antioxidant, and 0.5-2 parts rust inhibitor.
[0012] Preferably, the base oil is dimethyl silicone oil or modified silicone oil.
[0013] The combination of the aforementioned specific base oils can reduce the product's low-temperature torque and also improve the product's plastic compatibility.
[0014] Preferably, the modified silicone oil includes any one or a combination of at least two of amino-modified silicone oil, polyether-modified silicone oil, epoxy-modified silicone oil, methylphenyl silicone oil, hydrogen-containing silicone oil, and fluorosilicone oil. For example, a combination of amino-modified silicone oil and polyether-modified silicone oil, a combination of polyether-modified silicone oil and epoxy-modified silicone oil, or a combination of methylphenyl silicone oil and hydrogen-containing silicone oil, etc., but not limited to the combinations listed above. Other combinations not listed above are also applicable, with methylphenyl silicone oil being preferred.
[0015] Preferably, the thickener is a metal soap formed by reacting at least one organic acid with at least one metal hydroxide or metal oxide, such as a combination of dodecyl stearic acid and metal hydroxide, a combination of hydrogenated castor oil and metal hydroxide, or a combination of dodecyl stearic acid, hydrogenated castor oil and metal hydroxide, etc., but not limited to the combinations listed above. Other combinations not listed above are also applicable, with a preferred combination being a combination of dodecyl stearic acid, hydrogenated castor oil and metal hydroxide.
[0016] The aforementioned specific thickeners can improve the stability and shear stability of the product and reduce the low-temperature torque of the product. At the same time, by using a combination of dodecyl stearic acid and hydrogenated castor oil, the three-dimensional soap fiber network formed by the reaction with metal hydroxide is more elastic, which significantly improves the mechanical stability of the grease, and results in better consistency retention after long-term shearing and less softening.
[0017] Preferably, the metal hydroxide includes at least one of alkaline earth metals, aluminum, lithium, sodium, calcium, barium, and zinc, with lithium hydroxide being the most preferred.
[0018] Preferably, the anti-wear and friction-reducing agent comprises any one or a combination of at least two of polytetrafluoroethylene, molybdenum disulfide, graphite, modified boron nitride nanotubes, melamine cyanurate, or nano-sized zinc oxide. For example, a combination of molybdenum disulfide, graphite, and nano-sized zinc oxide; a combination of polytetrafluoroethylene, molybdenum disulfide, and graphite; a combination of molybdenum disulfide, graphite, and modified boron nitride nanotubes; and other combinations not listed above are also applicable. A combination of polytetrafluoroethylene, modified boron nitride nanotubes, and melamine cyanurate is preferred.
[0019] The aforementioned specific anti-wear and friction-reducing agents can effectively improve the anti-wear and friction-reducing performance of the product. At the same time, by using a specific combination of anti-wear and friction-reducing agents, the anti-wear and friction-reducing performance of the product can be maintained while reducing the use of polytetrafluoroethylene and saving costs.
[0020] Preferably, the amount of modified boron nitride nanotubes in the grease is 2-10 parts by weight, such as 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts or 10 parts, but not limited to the values listed above. Other unlisted values within the above range are also applicable.
[0021] The amount of modified boron nitride nanotubes used can reduce the amount of polytetrafluoroethylene used, saving costs and reducing wear.
[0022] Preferably, the antioxidant includes any one or a combination of at least two of benzotriazole and its derivatives, benzothiazole derivatives, hindered phenolic antioxidants, or peroxide decomposers. For example, a combination of benzotriazole and its derivatives and benzothiazole derivatives, a combination of benzotriazole and its derivatives and peroxide decomposers, or a combination of benzothiazole derivatives and hindered phenolic antioxidants. However, it is not limited to the combinations listed above. Other combinations not listed above are also applicable. Preferably, it is a combination of benzotriazole and its derivatives and hindered phenolic antioxidants.
[0023] Preferably, the grease further includes 0.5-2 parts by weight of rust inhibitor, such as 0.5 parts, 1 part, 1.5 parts or 2 parts, but not limited to the values listed above. Other unlisted values within the above range are also applicable.
[0024] The rust inhibitor includes any one or a combination of at least two of the following: carboxylic acid type, amine type, or sulfonate type rust inhibitors containing siloxane segments or silane coupling groups. For example, a combination of silane-modified amine type rust inhibitor and silane-modified sulfonate type rust inhibitor, a combination of silane-modified amide rust inhibitor and silane-modified sulfonate type rust inhibitor, etc., but not limited to the combinations listed above. Other combinations not listed above are also applicable. Preferably, a silane-modified sulfonate type rust inhibitor containing siloxane segments is preferred.
[0025] Secondly, this application provides a method for preparing the lubricating grease as described above, the method comprising the following steps: A portion of the base oil is mixed with an organic acid and heated to obtain a first mixture; the first mixture is reacted with a metal hydroxide to obtain a second mixture; then the mixture is heated and held at that temperature, and then mixed with the remaining base oil, anti-wear and friction reducing agent, and antioxidant to obtain the grease.
[0026] Preferably, the mixing with base oil, anti-wear and friction reducer, and antioxidant also includes mixing with rust inhibitor.
[0027] Preferably, the reaction time is at least 60 minutes.
[0028] Preferably, in the heating and holding process, the temperature is raised to 130-200℃ and the holding time is 10-60 min.
[0029] The reaction time can be 60 min, 70 min, 80 min, 90 min or 100 min, the temperature can be raised to 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃ or 200℃, and the holding time can be 10 min, 20 min, 30 min, 40 min, 50 min or 60 min, but is not limited to the values listed above. Other values not listed within the above range are also applicable.
[0030] Thirdly, the present invention also provides the application of the grease described above in the preparation of grease for shock absorber bearings.
[0031] Compared with the prior art, the present invention has the following beneficial effects: This invention provides a lubricating grease with good stability, excellent anti-wear and friction-reducing properties, superior high and low temperature performance, and good compatibility with plastic materials. The use of a specific thickener improves the product's stability and shear stability, reducing low-temperature torque. Furthermore, the use of a compound of dodecyl stearic acid and hydrogenated castor oil, reacting with metal hydroxides to form a more elastic three-dimensional soap fiber network, further enhances the grease's mechanical stability, resulting in better consistency retention after long-term shearing and reduced softening. The combination of specific base oils reduces low-temperature torque and improves compatibility with plastic materials. The use of specific anti-wear and friction-reducing agents effectively improves the product's anti-wear and friction-reducing properties. Moreover, the specific combination of anti-wear and friction-reducing agents reduces the use of polytetrafluoroethylene (PTFE), saving costs while maintaining the product's anti-wear and friction-reducing properties. Detailed Implementation
[0032] To further illustrate the technical means and effects of the present invention, the following describes the technical solution of the present invention in conjunction with preferred embodiments of the present invention. However, the present invention is not limited to the scope of the embodiments.
[0033] In the following examples, the dimethyl silicone oil was purchased from Dow Chemical, model PMX-200.
[0034] The methylphenyl silicone oil was purchased from Dow Chemical, model Z-1216.
[0035] The hindered phenolic antioxidant was purchased from BASF, model Irganox® L 115. Example 1
[0036] This embodiment provides a lubricating grease, the raw materials and mass ratio of which are as follows: 35 parts dimethyl silicone oil, 40 parts methylphenyl silicone oil, 5.5 parts dodecyl hydroxystearic acid, 9 parts hydrogenated castor oil, 2 parts lithium hydroxide, 2 parts polytetrafluoroethylene, 2 parts modified boron nitride nanotubes, 2 parts melamine urate, 1 part benzotriazole and its derivatives, 1 part hindered phenolic antioxidant, and 0.5 parts silane-modified sulfonate.
[0037] The preparation method is as follows: Dimethyl silicone oil, dodecyl stearic acid, and hydrogenated castor oil were added to a reaction vessel and heated to 90°C for mixing. Lithium hydroxide and distilled water were added to a melting vessel and heated to 50°C for mixing. The liquid from the melting vessel was then poured into the reaction vessel and reacted for 60 min. The temperature was then raised to 160°C and held for 30 min. Methylphenyl silicone oil was added, and the temperature was lowered to 80°C. Polytetrafluoroethylene, modified boron nitride nanotubes, melamine urate, benzotriazole and its derivatives, hindered phenolic antioxidants, and silane-modified sulfonate were added. After stirring, the mixture was discharged from the vessel and ground to obtain the grease. Example 2
[0038] This embodiment provides a lubricating grease, the raw materials and mass ratio of which are as follows: 35 parts dimethyl silicone oil, 40 parts fluorosilicone oil, 5 parts dodecyl stearic acid, 8 parts hydrogenated castor oil, 2 parts lithium hydroxide, 6 parts polytetrafluoroethylene, 1.5 parts benzotriazole and its derivatives, 1.5 parts hindered phenolic antioxidant, and 1 part silane-modified sulfonate.
[0039] The preparation method is the same as in Example 1. Example 3
[0040] This embodiment provides a lubricating grease, the raw materials and mass ratio of which are as follows: 40 parts dimethyl silicone oil, 35 parts methylphenyl silicone oil, 5 parts dodecyl stearic acid, 7 parts hydrogenated castor oil, 1.8 parts lithium hydroxide, 4 parts polytetrafluoroethylene, 1 part modified boron nitride nanotubes, 2 parts melamine urate, 1 part benzotriazole and its derivatives, 2 parts hindered phenolic antioxidants, and 1.2 parts silane-modified sulfonate.
[0041] The preparation method is the same as in Example 1. Example 4
[0042] This embodiment provides a lubricating grease, the raw materials and mass ratio of which are as follows: 32 parts dimethyl silicone oil, 40 parts methylphenyl silicone oil, 8.5 parts dodecyl hydroxystearic acid, 12 parts hydrogenated castor oil, 3 parts lithium hydroxide, 1 part polytetrafluoroethylene, 1 part modified boron nitride nanotubes, 1 part melamine urate, 0.5 parts benzotriazole and its derivatives, 0.5 parts hindered phenolic antioxidants, and 0.5 parts silane-modified sulfonate.
[0043] The preparation method is the same as in Example 1. Example 5
[0044] This embodiment provides a lubricating grease, the raw materials and mass ratio of which are as follows: 24 parts dimethyl silicone oil, 37 parts methylphenyl silicone oil, 10 parts dodecyl hydroxystearic acid, 10 parts hydrogenated castor oil, 3 parts lithium hydroxide, 4 parts polytetrafluoroethylene, 4 parts modified boron nitride nanotubes, 1 part melamine urate, 2.5 parts benzotriazole and its derivatives, 2.5 parts hindered phenolic antioxidants, and 2 parts silane-modified sulfonate.
[0045] The preparation method is the same as in Example 1. Example 6
[0046] This embodiment provides a lubricating grease, which is identical to that in Example 1 except that it does not contain dimethyl silicone oil and a portion of it is allocated to methylphenyl silicone oil.
[0047] The preparation method is the same as in Example 1. Example 7
[0048] This embodiment provides a lubricating grease, which is identical to that in Example 1 except that it does not contain methylphenyl silicone oil and a portion of it is allocated to dimethyl silicone oil.
[0049] The preparation method is the same as in Example 1. Example 8
[0050] This embodiment provides a lubricating grease, the raw materials of which are the same as in Example 1 except that hydrogenated castor oil is not included and a portion is reduced and allocated proportionally to dodecyl hydroxystearic acid and lithium hydroxide.
[0051] The preparation method is the same as in Example 1. Example 9
[0052] This embodiment provides a lubricating grease, the raw materials of which are the same as in Example 1 except that they do not contain dodecyl stearic acid and the reduced portion is allocated to hydrogenated castor oil and lithium hydroxide in proportion.
[0053] The preparation method is the same as in Example 1. Example 10
[0054] This embodiment provides a lubricating grease, which is identical to that in Example 1 except that lithium hydroxide is replaced with an equal amount of calcium hydroxide. Example 11
[0055] This embodiment provides a lubricating grease, which is identical to that in Example 1 except that half of the lithium hydroxide is replaced with an equal amount of calcium hydroxide.
[0056] Effect test: The greases provided in Examples 1-11 were tested, and the results are as follows:
[0057] The above data show that the grease provided by this invention has excellent stability, anti-wear properties, plastic compatibility, and low-temperature performance. Comparing Examples 1 and 2-5 reveals that this invention, through the synergistic effect of polytetrafluoroethylene (PTFE), modified boron nitride nanotubes, and melamine urate, effectively improves anti-wear and friction-reducing properties while reducing the amount of PTFE used. This helps reduce production costs, lessen environmental burden, and aligns with the industrial orientation of green manufacturing and sustainable development. Comparing Examples 1 and 6-7 reveals that this invention, through the synergistic effect of dimethyl silicone oil and methylphenyl silicone oil, effectively improves the plastic compatibility of the product, reduces starting torque and running torque at low temperatures, and improves low-temperature performance. Comparing Examples 1 and 9-11 reveals that this invention, through the synergistic effect of the compound of dodecyl stearic acid, hydrogenated castor oil, and lithium hydroxide, effectively reduces the change in extended working cone penetration (100,000 cycles), reduces oil separation in the steel mesh, effectively improves shear stability and product stability, and also reduces starting torque and running torque at low temperatures, thus improving low-temperature performance.
[0058] The applicant declares that the present invention is illustrated by the above embodiments to demonstrate the lubricating grease, its preparation method, and its application. However, the present invention is not limited to the above embodiments, that is, it does not mean that the present invention must rely on the above embodiments to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.
[0059] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.
[0060] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.
Claims
1. A lubricating grease, characterized in that, The grease comprises, by weight, 65-85 parts base oil, 8-15 parts thickener, 5-15 parts anti-wear and friction-reducing agent, 0.5-5 parts antioxidant, and 0.5-5 parts rust inhibitor; The base oil is selected from at least one of dimethyl silicone oil and modified silicone oil.
2. The lubricating grease according to claim 1, characterized in that, The grease comprises, by weight, 70-80 parts base oil, 10-13 parts thickener, 8-12 parts anti-wear and friction reducing agent, 2-4 parts antioxidant, and 0.5-2 parts rust inhibitor.
3. The lubricating grease according to claim 1 or 2, characterized in that, The base oil is dimethyl silicone oil and modified silicone oil; Preferably, the modified silicone oil includes any one or a combination of at least two of amino-modified silicone oil, polyether-modified silicone oil, epoxy-modified silicone oil, methylphenyl silicone oil, and hydrogen-containing silicone oil.
4. The lubricating grease according to any one of claims 1-3, characterized in that, The thickener is a metal soap formed by reacting at least one organic acid with at least one metal hydroxide or metal oxide; Preferably, the organic acid includes at least one of fatty carboxylic acids, cycloalkanoic acids, and aromatic acids, with dodecyl stearic acid being the most preferred. Preferably, the metal is selected from at least one of alkaline earth metals, aluminum, lithium, sodium, calcium, barium, and zinc, with lithium hydroxide and calcium hydroxide being more preferred.
5. The lubricating grease according to any one of claims 1-4, characterized in that, The wear-resistant and friction-reducing agent includes any one or a combination of at least two of polytetrafluoroethylene, molybdenum disulfide, graphite, modified boron nitride nanotubes, melamine cyanurate, or nano-sized zinc oxide, preferably a combination of polytetrafluoroethylene, modified boron nitride nanotubes, and melamine cyanurate.
6. The lubricating grease according to any one of claims 1-5, characterized in that, The antioxidant includes any one or a combination of at least two of benzotriazole and its derivatives, benzothiazole derivatives, hindered phenolic antioxidants, or peroxide decomposers, preferably a combination of benzotriazole and its derivatives and hindered phenolic antioxidants.
7. The lubricating grease according to any one of claims 1-6, characterized in that, The grease also includes 0.5-2 parts by weight of rust inhibitor; The rust inhibitor includes any one or a combination of at least two of the following: carboxylic acid type, amine type, or sulfonate type rust inhibitors containing siloxane segments or silane coupling groups, preferably sulfonate type rust inhibitors containing siloxane segments.
8. A method for preparing a lubricating grease according to any one of claims 1-7, characterized in that, The preparation method includes the following steps: A portion of the base oil is mixed with an organic acid and heated to obtain a first mixture; the first mixture is reacted with a metal hydroxide to obtain a second mixture; then the mixture is heated and held at that temperature, and then mixed with the remaining base oil, anti-wear and friction reducing agent, and antioxidant to obtain the grease.
9. The preparation method according to claim 8, characterized in that, The mixing with ester oils, anti-wear and friction reducing agents, and antioxidants also includes mixing with rust inhibitors; Preferably, the reaction time is at least 60 minutes; Preferably, in the heating and holding process, the temperature is raised to 130-200℃ and the holding time is 10-60 min.
10. The use of a grease according to any one of claims 1-7 in the preparation of a shock absorber bearing grease.