Self-lubricating rubber material as well as preparation method and application thereof

Abstract

The invention discloses a self-lubricating rubber material as well as a preparation method and application thereof. The self-lubricating rubber material comprises the following components in parts by weight: 80-120 parts of silicon-containing rubber, 30-70 parts of fumed silica, 15-35 parts of phenyl silicone oil, 3-10 parts of amino silicone oil, 5-15 parts of calcium oxide, 3-6 parts of a vulcanizing agent and 2-5 parts of an antibacterial agent. The granularity of the calcium oxide is 500 to 3000 meshes; the viscosity of the phenyl silicone oil at 25 DEG C is 500-1000 mm < 2 > / s. The self-lubricating rubber material provided by the invention has long-acting self-lubricating performance, excellent mechanical performance and excellent aging resistance, can be used as an excellent sealing material, and is widely applied to gate valve switch sealing in the fields of municipal water supply and drainage, petrochemical engineering, industrial pipelines, fire fighting systems and the like.

Description

Technical Field

[0001] This invention belongs to the field of rubber material technology, and more specifically, relates to a self-lubricating rubber material, its preparation method, and its application. Background Technology

[0002] With the continuous upgrading of modern industrial pipeline systems, the performance requirements for valve sealing materials are also increasing. Traditional rubber materials generally require the addition of lubricant during use. Once their lubrication performance fails, it will lead to increased torque during valve opening and closing, accelerating the aging and wear of the sealing material, thereby causing seal failure and media leakage, resulting in safety problems.

[0003] To address this challenge, self-lubricating rubber materials have emerged. These materials incorporate solid lubricants or oil reservoirs into the rubber matrix, enabling the spontaneous formation and continuous replenishment of a lubricating film at the friction interface. This eliminates the need for external lubricant addition, effectively extending valve lifespan and improving operational efficiency. However, despite these advantages, the durability of existing self-lubricating rubber materials needs further improvement. They often exhibit a rapid and concentrated release of lubricating components during the initial stages of use, resulting in a short duration of self-lubricating performance. Once the built-in lubricant is depleted, the self-lubricating rubber material reverts to a state similar to traditional rubber materials. This necessitates periodic shutdowns, repeated replenishment of external lubricant, or replacement of spare parts to maintain performance, increasing maintenance costs and impacting the reliability of continuous equipment operation.

[0004] Therefore, it is particularly important to develop a self-lubricating rubber material with long-lasting self-lubricating properties. Summary of the Invention

[0005] The primary objective of this invention is to overcome the shortcomings or defects of existing self-lubricating rubber materials and to provide a self-lubricating rubber material. The self-lubricating rubber material of this invention possesses long-lasting self-lubricating properties.

[0006] Another object of the present invention is to provide a method for preparing the above-mentioned self-lubricating rubber material.

[0007] Another object of the present invention is to provide applications of the above-mentioned self-lubricating rubber material.

[0008] Another object of the present invention is to provide a metal composite plate.

[0009] Another object of the present invention is to provide a method for preparing the above-mentioned metal composite plate.

[0010] To solve the above-mentioned technical problems, the present invention is achieved through the following technical solution: A self-lubricating rubber material comprising the following components in parts by weight: Contains 80-120 parts of silicone rubber; 30-70 parts of fumed silica; 15-35 parts of phenyl silicone oil; 3-10 parts of amino silicone oil; 5-15 parts of calcium oxide; 3-6 parts of vulcanizing agent; 2-5 parts antibacterial agent; The particle size of the calcium oxide is 500~3000 mesh; The phenyl silicone oil has a viscosity of 500~1000 mm at 25°C. 2 / s.

[0011] The inventors discovered that adding a specific ratio of amino silicone oil and phenyl silicone oil to rubber materials can produce a synergistic effect, improving their lubrication performance. Through dipole-dipole interactions between the amino and phenyl groups and silicone rubber molecules, the two silicone oils synergistically construct a stable composite lubricating film structure at the friction interface. This structure effectively reduces the frictional loss of the lubricating components, thereby improving the long-term self-lubricating properties of the rubber material. The inventors further found that when the viscosity of the phenyl silicone oil is too low, it easily migrates to the interface and cannot synergistically form a film with the amino silicone oil, leading to a decrease in the long-term self-lubricating properties of the rubber material; conversely, when the viscosity of the phenyl silicone oil is too high, it is not conducive to its migration to the interface, resulting in a decrease in both the lubrication effect and the long-term performance of the rubber material.

[0012] In addition, the inventors also adjusted the precipitation rate of the two silicone oils in the rubber material by adding calcium oxide of a specific particle size, thus preventing them from precipitating rapidly during use and improving the long-term self-lubricating properties of the rubber material.

[0013] More preferably, the self-lubricating rubber material comprises the following components in parts by weight: Contains 80-120 parts of silicone rubber; 30-70 parts of fumed silica; 20-30 parts of phenyl silicone oil; 5-8 parts of amino silicone oil; 5-15 parts of calcium oxide; 3-6 parts of vulcanizing agent; 2-5 parts of antibacterial agent.

[0014] Increasing the particle size of calcium oxide increases the contact area with lubricating components in rubber materials, thereby improving its oil absorption effect. However, the increased particle size also affects the dispersion of calcium oxide in the rubber material, thus impacting its effectiveness in regulating the elution rate of lubricating components. Preferably, the particle size of the calcium oxide is 1000-2000 mesh.

[0015] Preferably, the silicone rubber is one of fluorosilicone rubber or silicone rubber.

[0016] In this invention, commonly used fluorosilicone rubbers in the prior art can be selected, such as, but not limited to, Momentive FSE7340, Momentive FSE7540, Momentive FSE7560, etc.

[0017] In this invention, commonly used silicone rubbers in the prior art can be selected, such as, but not limited to, NE-9770, NE-9370, and NE-8171 from Dongjue Silicone Group Co., Ltd.

[0018] In this invention, commonly used fumed silica in the prior art can be selected, such as, but not limited to, Hubei Huifu HL150, Hubei Huifu HL200, and Hubei Huifu HL260.

[0019] Preferably, the phenyl silicone oil is one or both of methylphenyl silicone oil and diphenyl silicone oil.

[0020] It should be noted that the viscosity test method of the phenyl silicone oil at 25°C in this invention can refer to the ASTM D445 standard.

[0021] Amino silicone oils with ammonia values ​​within the conventional commercial range can be used in this invention. Optionally, the amino silicone oil has an ammonia value of 0.4 to 0.9, such as, but not limited to, Dow Corning OFX-8040A, Dow Corning SF-8417, and Dow Corning OFX-8468.

[0022] Preferably, the vulcanizing agent is one or more of di-tert-butyl peroxide, dicumyl peroxide, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane, or bis(2,4-dichlorobenzoyl peroxide).

[0023] In this invention, commonly used antibacterial agents in the prior art can be selected, such as, but not limited to, Guangzhou Yijia YJ-SZ-815 / YJ-GJ-865, Dongguan Shimaide Biotechnology Co., Ltd. SMD-GJ036, Guangzhou Jianis Anti-mildew and Antibacterial Technology Co., Ltd. AEM-5700GJ, Guangzhou Xiyou New Material Technology Co., Ltd. XY-K09 / 10 / 08, etc.

[0024] The preparation method of the above-mentioned self-lubricating rubber material is also within the scope of protection of this invention, and includes the following steps: S1. Silicone rubber, fumed silica, phenyl silicone oil and amino silicone oil are mixed in one step to obtain a pre-product; S2. Add calcium oxide and antibacterial agent to the pre-product for secondary mixing, let stand and cool to obtain the compound; S3. Mix the compound rubber and vulcanizing agent evenly to obtain the self-lubricating rubber material.

[0025] Preferably, the temperature of the first mixing step is 100~120℃.

[0026] Preferably, the mixing time for one mixing cycle is 40-80 minutes.

[0027] Preferably, the temperature of the secondary mixing is 160~170℃.

[0028] Preferably, the secondary mixing time is 40-80 minutes.

[0029] As is known to those skilled in the art, rubber is prone to oxidation under high temperature and shear conditions, leading to molecular chain breakage and affecting the final rubber material's properties. Therefore, vacuum conditions must be maintained during the mixing process. Simultaneously, a higher vacuum level effectively lowers the boiling points of moisture and low-molecular-weight volatiles, making them easier to remove. Preferably, the vacuum level during the primary or secondary mixing process is (-0.05) to (-0.09) MPa.

[0030] Those skilled in the art will know that during the mixing process, the uniformity of rubber material dispersion can be improved by adjusting the roller gap in stages and coordinating with multiple rolling operations. Preferably, the uniform mixing operation includes the following steps: S1. Setting the roller gap to 5mm and rolling 3 times; S2. Setting the roller gap to 3mm and rolling 5 times; S3. Setting the roller gap to 5mm and rolling 3 times.

[0031] The application of the aforementioned self-lubricating rubber material in metal composite plates is also within the scope of protection of this invention.

[0032] The present invention provides a metal composite plate, comprising a metal plate and the aforementioned self-lubricating rubber material.

[0033] The preparation method of the above-mentioned metal composite plate is also within the scope of protection of this invention, and includes the following steps: S1. First, treat the surface of the metal plate, then spray or brush the adhesive onto the surface of the metal plate, and finally dry and cure it for later use. S2. Press the above self-lubricating rubber material with the metal plate on both sides and perform vulcanization molding in one step to obtain the crude finished product; S3. The crude product is subjected to secondary vulcanization molding to obtain the metal composite plate.

[0034] Preferably, the metal plate is either 304# stainless steel plate or 301# stainless steel plate.

[0035] Those skilled in the art will know that contaminants such as rust, oxide layers, oil, moisture, or dust commonly found on metal sheets can severely weaken the adhesion between rubber materials and metal. Therefore, surface treatment of the metal sheet is necessary before bonding. Surface treatment methods can refer to existing technologies, such as degreasing and cleaning, and mechanical polishing.

[0036] In this invention, commonly used adhesives in the prior art can be selected, such as, but not limited to, Dow FLB315, Chemlock 608, and Shin-Etsu 34T.

[0037] Preferably, the drying temperature is 70~90℃.

[0038] Preferably, the drying time is 10-20 minutes.

[0039] As those skilled in the art will know, in the bonding process between rubber materials and metal plates, the coating thickness of the adhesive is a key parameter affecting the bonding performance. If the coating is too thick, uneven curing will occur; if the coating is too thin, poor bonding will result. Preferably, the coating thickness of the adhesive is 0.03~0.08 mm.

[0040] Preferably, the temperature for the first vulcanization molding is 170~180℃.

[0041] Preferably, the vulcanization molding time is 50-70 minutes.

[0042] Preferably, the pressure of the single vulcanization molding is 18~25MPa.

[0043] Preferably, the temperature of the secondary vulcanization molding is 190~210℃.

[0044] Preferably, the secondary vulcanization molding time is 2-4 hours.

[0045] Compared with the prior art, the beneficial effects of the present invention include: This invention provides a self-lubricating rubber material. By adding phenyl silicone oil and amino silicone oil to the rubber material, its lubrication performance is improved, and a composite lubricating film structure is synergistically constructed at the friction interface. This structure effectively reduces the frictional loss of the lubricating components, thereby improving the long-term self-lubricating performance of the rubber material. Simultaneously, the addition of calcium oxide to the rubber material regulates the precipitation rate of the lubricating components, preventing rapid precipitation during use and further enhancing the long-term self-lubricating performance. The self-lubricating rubber material provided by this invention combines long-term self-lubricating properties, excellent mechanical properties, and outstanding aging resistance. It can be used as an excellent sealing material and is widely applied in gate valve sealing in municipal water supply and drainage, petrochemical, industrial pipelines, and fire protection systems. Detailed Implementation

[0046] The present invention will be further described below with reference to embodiments and comparative examples. These embodiments are merely typical descriptions of the present invention, but the present invention is not limited thereto. Unless otherwise specified, the test methods used in the following embodiments and comparative examples are conventional methods, and the raw materials and reagents used are commercially available from conventional commercial sources.

[0047] Raw materials used in each embodiment and comparative example: Silicone rubber 1: Fluorosilicone rubber, FSE7340, Momentive Silicones, Inc., USA; Silicone rubber 2: Fluorosilicone rubber, FSE7540, Momentive Silicones, Inc., USA; Silicone rubber 3: Fluorosilicone rubber, FSE7560, Momentive Silicones, Inc., USA; Silicone rubber 4: Silicone rubber, NE-9770, Dongjue Organosilicon Group Co., Ltd.; Fumed silica 1: HL150, Hubei Huifu Nanomaterials Co., Ltd.; Fumed silica 2: HL260, Hubei Huifu Nanomaterials Co., Ltd.; Phenyl silicone oil 1: AP1000, Wacker Chemie AG, Germany, with a viscosity of 1000 mm at 25°C. 2 / s; Phenyl silicone oil 2: AP500, Wacker Chemie AG, Germany, with a viscosity of 500 mmHg at 25°C. 2 / s; Phenyl silicone oil 3:255-200, Shanghai Kaiping Resin Co., Ltd., viscosity at 25℃ is 200 mmHg. 2 / s; Phenyl silicone oil 4: 255-1500, Datong Chemical (Guangzhou) Co., Ltd., viscosity at 25℃ is 1500 mm. 2 / s; Amino silicone oil 1: OFX-8040A, Dow Corning Silicones, Inc., USA, with an amino value of 0.4; Amino silicone oil 2: SF-8417, Dow Corning Silicones, Inc., USA, with an amino value of 0.9; Calcium oxide 1: Jiangxi Chuangxian Fine Calcium Industry Co., Ltd., particle size 1500 mesh; Calcium oxide 2: Ultrafine calcium oxide, Guilin Haowang New Materials Co., Ltd., with a particle size of 3000 mesh; Calcium oxide 3: Jiande Taihe New Materials Co., Ltd., particle size 500 mesh; Calcium oxide 4: Liaoning Xinfei Calcium Industry Co., Ltd., particle size 100 mesh. Calcium oxide 5: Lingshou Ruojia Mineral Products Co., Ltd., particle size 4000 mesh; Vulcanizing agent: 2,5-dimethyl-2,5-di-tert-butylperoxide, Akzo Chemical Co., Ltd.; Antibacterial agent: YJ-SZ-815, Guangzhou Yijia Technology Co., Ltd.; Adhesive: FLB315, Dow Chemical Company, USA.

[0048] The same reagents were used in parallel experiments of all embodiments and comparative examples of this invention.

[0049] In Examples 1-21 and Comparative Examples 1-8, different self-lubricating rubber materials were provided and prepared by the following methods, including the following steps: S1. Weigh out each ingredient according to the formula and set aside; S2. Fluorosilicone, fumed silica, phenyl silicone oil, and amino silicone oil are added to a kneader for a single mixing process to obtain the pre-product; S3. Add calcium oxide and antibacterial agent to the pre-product for secondary mixing, let stand and cool to obtain the compound; S4. Add the compounded rubber and vulcanizing agent to the open mill and mix evenly to obtain the self-lubricating rubber material.

[0050] The detailed formulations of each embodiment and comparative example are shown in Tables 1-3. Table 1. Formulations of self-lubricating rubber materials in Examples 1-11 (unit: g)

[0051] Table 2 Formulations of self-lubricating rubber materials in Examples 12-21 (unit: g)

[0052] Table 3 Formulations of self-lubricating rubber materials in Comparative Examples 1-8 (unit: g)

[0053] Rubber material performance testing The self-lubricating rubber materials prepared in the above embodiments and comparative examples were subjected to performance tests, and the test results are shown in Table 4. The specific test methods are as follows: 1. Hardness test: The hardness of the material was tested at room temperature using the LX-A rubber hardness tester from Shanghai Zijiu Measuring Tools Co., Ltd., in accordance with the test method of GB / T531.1-2008.

[0054] 2. Tensile strength test: In accordance with the test method of GB / T 528-2009, under the standard laboratory environment (temperature of 23±2℃ and relative humidity of 50±5%), the test sample is made into a type I dumbbell-shaped specimen and tested using an AI-7000-SU1 rubber tensile testing machine.

[0055] 3. Elongation at break test: In accordance with the test method of GB / T 528-2009, the test sample is made into a type I dumbbell-shaped specimen under standard laboratory environment (temperature 23±2℃, relative humidity 50±5%), and tested using AI-7000-SU1 rubber tensile testing machine.

[0056] 4. Heat aging resistance: In accordance with the test method of GB / T 3512-2014, the GT-7017-ELU high temperature aging test chamber was used to age the test samples at 150℃ for 72 hours. The heat aging resistance of the test samples was evaluated by comparing the hardness, tensile strength and elongation of the test samples before and after aging.

[0057] Table 4 Performance test results of self-lubricating rubber materials

[0058] As shown in Table 4, the self-lubricating rubber material provided by this invention has excellent mechanical properties and aging resistance.

[0059] Application testing (1) Preparation of composite metal plates: The self-lubricating rubber materials prepared in the above embodiments and comparative examples are used to make composite metal plates. The specific preparation method includes the following steps: S1. Dilute the adhesive FLB-315 with ethyl acetate to prepare an adhesive solution with a volume ratio of 50%; S2. First, perform surface treatment on the metal plate, then spray the adhesive solution onto the surface of the metal plate with an adhesive coating thickness of 0.05mm, and finally place it in an 80℃ drying oven for 15 minutes for later use. S3. Heat the vacuum flat vulcanizing machine (350T) to 180℃, place the metal plate obtained in step S2 and the self-lubricating rubber material in the machine and press them together on both sides for one-time vulcanization molding. The process conditions for one-time vulcanization molding are: pressure 20MPa, time 10min; S4. Place the product obtained in step S3 into a 200℃ forced-air drying oven for secondary vulcanization molding to obtain the composite metal plate. The process conditions for secondary vulcanization molding are: time 4h.

[0060] (2) Performance testing of composite metal plates: The composite metal plates prepared above were subjected to performance tests, and the test results are shown in Table 5. The specific test methods are as follows: 1. Friction coefficient test: The dynamic friction coefficient was tested using the slider method according to GB / T40721-2021: a slider of known mass was placed on the rubber surface of the composite metal plate, and the dynamic friction coefficient was calculated by measuring its sliding distance and time. The test was conducted in a standard laboratory environment (temperature 23±2℃, relative humidity 50±5%), using a dynamic friction coefficient tester (model: GT-7012-F1H).

[0061] 2. Rebound rate test: According to the test method of GB / T1681-2009, the rebound rate tester was used to conduct the test in a standard laboratory environment (temperature of 23±2℃ and relative humidity of 50±5%).

[0062] 3. Self-lubricating performance duration test: Referring to the test method of GB / T 3512-2014, the GT-7017-ELU high temperature aging test chamber was used to age the test samples at 150℃. The oil production on the surface of the test samples was observed every day, and the duration of self-lubrication was recorded.

[0063] Table 5 Performance test results of composite metal plates

[0064] As shown in Table 5, the self-lubricating rubber material provided by this invention exhibits excellent lubrication properties, with a coefficient of friction ranging from 0.03 to 0.10. The duration of self-lubricating performance can be significantly improved by adding calcium oxide of a specific particle size.

[0065] As can be seen from Comparative Examples 1 and 2, when the particle size of the added calcium oxide is not in the range of 500 to 3000 mesh, it is difficult to effectively control the precipitation rate of the lubricating component, resulting in a significant reduction in its self-lubricating duration.

[0066] As can be seen from Comparative Examples 3 to 6, adding a specific proportion of amino silicone oil and phenyl silicone oil to rubber materials can improve their lubrication performance and simultaneously construct a stable composite lubrication film structure at the friction interface, effectively reducing the frictional loss of lubricating components and thus improving the long-term self-lubricating performance of rubber materials.

[0067] Comparative Examples 7 and 8 show that when the viscosity of phenyl silicone oil at 25°C is less than 500 mm³, 2At a viscosity of 1000 mS, it easily migrates and cannot form a composite lubricating film with amino silicone oil at the friction interface, resulting in a significant reduction in its self-lubricating duration. When the viscosity of phenyl silicone oil at 25°C is greater than 1000 mS... 2 When the value is / s, it is not conducive to its migration to the interface, which significantly shortens its lubrication performance and self-lubrication duration.

[0068] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A self-lubricating rubber material, characterized in that, Includes the following components by weight: Contains 80-120 parts of silicone rubber; 30-70 parts of fumed silica; 15-35 parts of phenyl silicone oil; 3-10 parts of amino silicone oil; 5-15 parts of calcium oxide; 3-6 parts of vulcanizing agent; 2-5 parts antibacterial agent; The particle size of the calcium oxide is 500~3000 mesh; The phenyl silicone oil has a viscosity of 500~1000 mm at 25°C. 2 / s.

2. The self-lubricating rubber material according to claim 1, characterized in that, Includes the following components by weight: Contains 80-120 parts of silicone rubber; 30-70 parts of fumed silica; 20-30 parts of phenyl silicone oil; 5-8 parts of amino silicone oil; 5-15 parts of calcium oxide; 3-6 parts of vulcanizing agent; 2-5 parts of antibacterial agent.

3. The self-lubricating rubber material according to claim 1 or 2, characterized in that, The calcium oxide has a particle size of 1000~2000 mesh.

4. The self-lubricating rubber material according to claim 1 or 2, characterized in that, The silicone rubber is either fluorosilicone rubber or silicone rubber.

5. The self-lubricating rubber material according to claim 1 or 2, characterized in that, The phenyl silicone oil is one or both of methylphenyl silicone oil and diphenyl silicone oil.

6. The self-lubricating rubber material according to claim 1 or 2, characterized in that, The amino silicone oil has an ammonia value of 0.4 to 0.

9.

7. A method for preparing the self-lubricating rubber material according to any one of claims 1 to 6, characterized in that, Includes the following steps: S1. Silicone rubber, fumed silica, phenyl silicone oil and amino silicone oil are mixed in one step to obtain a pre-product; S2. Add calcium oxide and antibacterial agent to the pre-product for secondary mixing, let stand and cool to obtain the compound; S3. Mix the compound rubber and vulcanizing agent evenly to obtain the self-lubricating rubber material.

8. The application of the self-lubricating rubber material according to any one of claims 1 to 6 in metal composite plates.

9. A metal composite plate, characterized in that, The metal composite plate comprises a metal plate and the self-lubricating rubber material according to any one of claims 1 to 6.

10. The method for preparing the metal composite plate according to claim 9, characterized in that, Includes the following steps: S1. First, treat the surface of the metal plate, then spray or brush the adhesive onto the surface of the metal plate, and finally dry and cure it for later use. S2. Press the self-lubricating rubber material according to any one of claims 1 to 6 onto a metal plate on both sides and perform vulcanization molding in one step to obtain the crude finished product; S3. The crude product is subjected to secondary vulcanization molding to obtain the metal composite plate.

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