A kind of self-lubricating vulcanized silicone rubber and preparation method thereof

Abstract

The present invention specifically relates to a self-lubricating vulcanized silicone rubber and a preparation method thereof, wherein the self-lubricating vulcanized silicone rubber comprises the following raw materials in parts by weight: 80-90 parts of base rubber, 10-20 parts of reinforcing filler, 5-10 parts of epoxy resin modified silane, 2-5 parts of hydroxy fluorosilicone oil, 4-10 parts of oil separation aid, 1-2 parts of cerium dioxide, 4-8 parts of synergist, and 1-5 parts of vulcanizing agent. The self-lubricating vulcanized silicone rubber of the present invention has good heat stability, oil resistance and mechanical properties, and has the characteristics of low compression permanent deformation, can be applied to technical fields such as automotive wiring harness sealing and mechanical dynamic sealing, has good sealing, long service life and wide application range. The preparation method of the vulcanized silicone rubber is easy to operate and control, has high production efficiency, and is conducive to industrial production.

Description

Technical Field

[0001] The invention relates to the technical field of composite materials, and in particular to a self-lubricating vulcanized silicone rubber and a preparation method thereof. Background Art

[0002] Silicone rubber is a polymer compound composed of silicon atoms and oxygen atoms, which has excellent high temperature resistance, oxidation resistance and aging resistance. However, there are significant differences in the shelf life of different types of silicone rubber. Common silicone rubber is mainly divided into room temperature vulcanized silicone rubber (RTV) and high temperature vulcanized silicone rubber (HTV). With the development of economy and the advancement of science and technology, the application scope of silicone rubber is becoming more and more extensive, and the performance is becoming more and more diversified to meet the application requirements.

[0003] Self-lubricating silicone rubber is a high-performance rubber with self-lubricating properties. It can reduce wear and friction without the introduction of lubricants, which helps to improve the service life and efficiency of mechanical equipment. At present, self-lubricating silicone rubber has been widely used in aerospace, automobile manufacturing, electronic appliances, medical equipment and other fields. For example, self-lubricating silicone rubber is widely used in bearings, assemblies and sealing elements, which can effectively reduce the wear and friction of mechanical equipment. When used in the sealing parts of mechanical equipment, it can effectively improve the waterproof and sealing performance of the equipment, and improve the service life and efficiency of the equipment.

[0004] With the development of economy and the progress of science and technology, the existing industrial production and products have also put forward better requirements for the performance of self-lubricating silicone rubber. However, although the existing self-lubricating silicone rubber has many advantages and protects equipment parts from failure due to excessive wear, it still often has problems such as poor mechanical properties, poor heat resistance stability and poor compression permanent deformation performance. It is difficult to meet the higher requirements for self-lubricating silicone rubber in high value-added technical fields such as automotive wiring harness sealing and mechanical dynamic sealing, and further improvement is needed. Summary of the invention

[0005] The purpose of the present invention is to provide a self-lubricating vulcanized silicone rubber to solve the above-mentioned deficiencies in the prior art. The self-lubricating vulcanized silicone rubber has good heat stability, oil resistance and mechanical properties, has the characteristics of low compression permanent deformation, and has a long service life. The preparation method of the vulcanized silicone rubber is easy to operate and control, has high production efficiency, and is conducive to industrial production.

[0006] The purpose of the present invention is achieved through the following technical scheme: a self-lubricating vulcanized silicone rubber, comprising the following raw materials in parts by weight: 80-90 parts of base rubber, 10-20 parts of reinforcing filler, 5-10 parts of epoxy resin modified silane, 2-5 parts of hydroxy fluorosilicone oil, 4-10 parts of oil separation aid, 1-2 parts of cerium dioxide, 4-8 parts of synergist, and 1-5 parts of vulcanizer.

[0007] Furthermore, each portion of the base rubber includes 65-75 portions of methyl vinyl silicone rubber and 15-25 portions of fluorosilicone rubber.

[0008] Furthermore, the oil separation aid is at least one of methylphenyl silicone oil and diphenyl silicone oil.

[0009] Furthermore, the reinforcing filler is white carbon black; the white carbon black is at least one of precipitated white carbon black and fumed white carbon black.

[0010] Furthermore, the white carbon black is composed of precipitated white carbon black and fumed white carbon black in a weight ratio of 0.5-2:0.5-2. The present invention adopts a mixture of precipitated white carbon black and fumed white carbon black, and the precipitated white carbon black and fumed white carbon black have good dispersibility in the vulcanized silicone rubber system, which helps to improve the mechanical properties and thermal stability of the vulcanized silicone rubber.

[0011] Furthermore, the vulcanizing agent is at least one of di-tert-butyl peroxide, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane and bis(2,4-dichlorobenzoyl)peroxide.

[0012] Furthermore, the preparation method of the synergist comprises the steps of: taking 15-20 parts of aluminum silicate, 1-2 parts of dimethylsilyl cage-shaped polysilsesquioxane and 40-50 parts of ethanol by weight, mixing them evenly, then adding 0.01-0.015 parts of potassium hydroxide, reacting at a temperature of 50-60°C for 3-5h, and then removing the ethanol to obtain the synergist. The present invention mixes aluminum silicate and dimethylsilyl cage-shaped polysilsesquioxane in the above manner, and reacts them under the condition of potassium hydroxide as a catalyst to obtain a synergist. The synergist is added to the silicone rubber system, which helps to reduce the compression permanent deformation of the silicone rubber and helps to improve the mechanical properties and thermal stability of the silicone rubber.

[0013] The self-lubricating vulcanized silicone rubber of the present invention is prepared by adding reinforcing fillers, epoxy resin modified silane, hydroxy fluorosilicone, oil separation aid, cerium dioxide, synergist and other raw materials to the base rubber, and each raw material is well matched. The self-lubricating vulcanized silicone rubber has good heat stability, oil resistance and mechanical properties and has the characteristics of low compression permanent deformation, which can effectively improve the service life of the vulcanized silicone rubber product. There are more active free hydroxyl groups on the surface of silica, which can effectively inhibit the deformation of the silicone rubber molecular chain and achieve a reinforcing effect. However, due to the presence of surface hydroxyl groups, it is easy for particles to agglomerate when mixing silicone rubber, making it difficult for silica to be evenly dispersed in the system, resulting in a structuring phenomenon. The present invention uses hydroxy fluorosilicone oil as a structure control agent, which can condense with the active hydroxyl groups of silica, inhibit the structuring between silica and silica gel, improve the processing performance of silicone rubber, and improve the heat stability and oil resistance of silicone rubber.

[0014] Furthermore, the preparation method of the epoxy resin modified silane comprises the following steps: mixing epoxy resin and γ-methacryloxypropyltrimethoxysilane at a molar ratio of 1:1.5-3 under the condition of nitrogen, and reacting at a temperature of 40-50°C for 60-90 minutes to obtain epoxy resin modified silane. The present invention obtains epoxy resin modified silane by adopting the above method, and adds it to the vulcanized silicone rubber system, which helps to improve the mechanical properties of the vulcanized silicone rubber and can significantly increase the tensile strength and tear strength of the silicone rubber.

[0015] Furthermore, the preparation method of the fluorosilicone raw rubber comprises the following steps:

[0016] (A1) by weight, γ-trifluoropropylmethyltrisiloxane and octamethylcyclotetrasiloxane are added to a reactor in a molar ratio of 1:3, and then alkali glue is added and mixed evenly, wherein the amount of alkali glue added is 0.8-1.5% of the total weight of γ-trifluoropropylmethyltrisiloxane and octamethylcyclotetrasiloxane;

[0017] (A2) nitrogen is introduced, and the mixture in step (A1) is stirred at a vacuum degree of (-0.07)-(-0.1) MPa and a temperature of 67-73°C for 45-70 minutes; then the temperature is raised to 90-100°C, and the reaction is carried out at a vacuum degree of (-0.04)-(-0.06) MPa for 70-110 minutes; the temperature is then raised to 102-105°C, deionized water is added and stirred, and the amount of deionized water added is 1-1.5% of the total weight of γ-trifluoropropylmethyltrisiloxane and octamethylcyclotetrasiloxane; the reaction is continued for 100-140 minutes; then the temperature is raised to 155-165°C and kept warm for 45-70 minutes; finally, the cyclic small molecule by-products in the reaction system are removed at a vacuum degree of (-0.07)-(-0.1) MPa to obtain fluorosilicone raw rubber.

[0018] The present invention prepares fluorosilicone rubber by mixing γ-trifluoropropylmethyltrisiloxane and octamethylcyclotetrasiloxane and using deionized water as a capping agent. The fluorosilicone rubber and methyl vinyl silicone rubber are compounded as base rubber, and compounded with epoxy resin modified silane, hydroxy fluorosilicone, oil separation aid, cerium dioxide, synergist, etc., which helps to improve the oil resistance and thermal stability of vulcanized rubber and give the vulcanized rubber good mechanical properties.

[0019] Another object of the present invention is to provide a method for preparing a self-lubricating vulcanized silicone rubber, comprising the following steps:

[0020] (1) Put the base rubber into a kneader and stir;

[0021] (2) Under a nitrogen environment, reinforcing filler, hydroxy fluorosilicone oil, epoxy resin modified silane, and synergist are added to a kneader in multiple times, stirring evenly after each addition, and heating to obtain product A;

[0022] (3) After the product A is kneaded and molded, it is cooled, and the oil separation agent is added in multiple times, and stirred evenly after each addition; then cerium dioxide is added and mixed evenly to obtain a self-lubricating silicone rubber material;

[0023] (4) The self-lubricating silicone rubber is injected into the mold, a vulcanizing agent is added, and a primary vulcanization molding is performed, and then it is placed in hot air for secondary vulcanization to obtain a self-lubricating vulcanized silicone rubber.

[0024] Furthermore, in step (2), the temperature is raised to 150-160°C, and after hot refining for 90-150 minutes, vacuuming is performed, and the vacuum degree is (-0.05)-(-0.09) MPa.

[0025] Furthermore, in step (2), the reinforcing filler, hydroxy fluorosilicone oil, epoxy resin modified silane and synergist are added in 2-4 times, with the same amount added each time.

[0026] Furthermore, in step (4), the primary vulcanization temperature is 170-180°C, and the vulcanization time is 5-10 minutes; the secondary vulcanization temperature is 180-210°C, and the vulcanization time is 2-4 hours.

[0027] The beneficial effects of the present invention are as follows: the self-lubricating vulcanized silicone rubber of the present invention is prepared by combining fluorosilicone raw rubber and methyl vinyl silicone rubber as base rubber, and combining with reinforcing fillers, epoxy resin modified silane, hydroxyl fluorosilicone oil, synergist and other raw materials, so that the prepared vulcanized silicone rubber has good heat stability, oil resistance and mechanical properties, and has the characteristics of low compression permanent deformation, and can be applied to technical fields such as automotive wiring harness sealing and mechanical dynamic sealing, and has good sealing, long service life and wide application range. The preparation method of the vulcanized silicone rubber is easy to operate and control, has high production efficiency, and is conducive to industrial production. DETAILED DESCRIPTION

[0028] In order to facilitate the understanding of those skilled in the art, the present invention is further described below in conjunction with embodiments, and the contents mentioned in the implementation modes are not intended to limit the present invention.

[0029] In some embodiments of the present invention, a self-lubricating vulcanized silicone rubber includes the following raw materials in parts by weight: 80-90 parts of base rubber, 10-20 parts of reinforcing filler, 5-10 parts of epoxy resin modified silane, 2-5 parts of hydroxy fluorosilicone oil, 4-10 parts of oil separation aid, 1-2 parts of cerium dioxide, 4-8 parts of synergist, and 1-5 parts of vulcanizer.

[0030] In some embodiments of the present invention, each part of the base rubber comprises 65-75 parts of methyl vinyl silicone rubber and 15-25 parts of fluorosilicone rubber. The molar fraction of vinyl in the methyl vinyl silicone rubber is 0.1%-0.3% (molar fraction).

[0031] In some embodiments of the present invention, the oil separation aid is at least one of methylphenyl silicone oil and diphenyl silicone oil.

[0032] In some embodiments of the present invention, the reinforcing filler is white carbon black; the white carbon black is at least one of precipitated white carbon black and fumed white carbon black.

[0033] Furthermore, the white carbon black is composed of precipitated white carbon black and fumed white carbon black in a weight ratio of 0.5-2:0.5-2.

[0034] In some embodiments of the present invention, the vulcanizing agent is at least one of di-tert-butyl peroxide, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane and bis(2,4-dichlorobenzoyl)peroxide.

[0035] In some embodiments of the present invention, the preparation method of the synergist comprises the following steps: by weight, 15-20 parts of aluminum silicate, 1-2 parts of dimethylsilyl cage-shaped polysilsesquioxane and 40-50 parts of ethanol are mixed evenly, then 0.01-0.015 parts of potassium hydroxide are added, reacting at a temperature of 50-60° C. for 3-5 hours, and then removing the ethanol to obtain the synergist.

[0036] In some embodiments of the present invention, the preparation method of the epoxy resin modified silane comprises the following steps: under the condition of nitrogen passing, epoxy resin and γ-methacryloxypropyltrimethoxysilane are mixed in a molar ratio of 1:1.5-3, and reacted at a temperature of 40-50°C for 60-90 minutes to obtain epoxy resin modified silane.

[0037] In some embodiments of the present invention, the method for preparing the fluorosilicone rubber comprises the following steps:

[0038] (A1) by weight, γ-trifluoropropylmethyltrisiloxane and octamethylcyclotetrasiloxane are added to a reactor in a molar ratio of 1:3, and then alkali glue is added and mixed evenly, wherein the amount of the alkali glue added is 0.8-1.5% of the sum of the weights of γ-trifluoropropylmethyltrisiloxane and octamethylcyclotetrasiloxane; the alkali glue is prepared by a mixed reaction of tetramethylammonium hydroxide and octamethylcyclotetrasiloxane; the γ-trifluoropropylmethyltrisiloxane and octamethylcyclotetrasiloxane are dried in advance;

[0039] (A2) nitrogen is introduced, and the mixture in step (A1) is stirred at a vacuum degree of (-0.07)-(-0.1) MPa and a temperature of 67-73°C for 45-70 minutes; then the temperature is raised to 90-100°C, and the reaction is carried out at a vacuum degree of (-0.04)-(-0.06) MPa for 70-110 minutes; the temperature is then raised to 102-105°C, deionized water is added and stirred, and the amount of deionized water added is 1-1.5% of the total weight of γ-trifluoropropylmethyltrisiloxane and octamethylcyclotetrasiloxane; the reaction is continued for 100-140 minutes; then the temperature is raised to 155-165°C and kept warm for 45-70 minutes; finally, the cyclic small molecule by-products in the reaction system are removed at a vacuum degree of (-0.07)-(-0.1) MPa to obtain fluorosilicone raw rubber.

[0040] Another object of the present invention is to provide a method for preparing a self-lubricating vulcanized silicone rubber, comprising the following steps:

[0041] (1) Put the base rubber into a kneader and stir;

[0042] (2) Under a nitrogen environment, reinforcing filler, hydroxy fluorosilicone oil, epoxy resin modified silane, and synergist are added to a kneader in multiple times, stirring evenly after each addition, and heating to obtain product A;

[0043] (3) After the product A is kneaded and molded, it is cooled, and the oil separation agent is added in multiple times, and stirred evenly after each addition; then cerium dioxide is added and mixed evenly to obtain a self-lubricating silicone rubber material;

[0044] (4) The self-lubricating silicone rubber is injected into the mold, a vulcanizing agent is added, and a pressurized vulcanization molding is performed, and then it is placed in hot air for secondary vulcanization to obtain a self-lubricating vulcanized silicone rubber.

[0045] Furthermore, in step (2), the temperature is raised to 150-160°C, and after hot refining for 90-150 minutes, vacuuming is performed, and the vacuum degree is (-0.05)-(-0.09) MPa.

[0046] Furthermore, in step (2), the reinforcing filler, hydroxy fluorosilicone oil, epoxy resin modified silane and synergist are added in 2-4 times, with the same amount added each time.

[0047] Furthermore, in step (4), the primary vulcanization temperature is 170-180°C, the pressure is 9-14Mpa, and the vulcanization time is 5-10min; the secondary vulcanization temperature is 180-210°C, and the vulcanization time is 2-4h.

[0048] This embodiment provides a self-lubricating vulcanized silicone rubber, comprising the following raw materials in parts by weight: 85 parts of base rubber, 15 parts of reinforcing filler, 8 parts of epoxy resin modified silane, 4 parts of hydroxy fluorosilicone oil, 7 parts of oil separation aid, 1.5 parts of cerium dioxide, 6 parts of synergist, and 2 parts of vulcanizer. The hydroxy fluorosilicone oil is HY-F-104 hydroxy fluorosilicone oil.

[0049] Furthermore, each portion of the base rubber comprises 67 portions of methyl vinyl silicone rubber and 18 portions of fluorosilicone rubber. The methyl vinyl silicone rubber is 110-2 type methyl vinyl silicone rubber.

[0050] Furthermore, the preparation method of the fluorosilicone raw rubber comprises the following steps:

[0051] (A1) by weight, γ-trifluoropropylmethyltrisiloxane and octamethylcyclotetrasiloxane are added to a reactor in a molar ratio of 1:2.2, and then alkali glue is added and mixed evenly, wherein the amount of alkali glue added is 1% of the total weight of γ-trifluoropropylmethyltrisiloxane and octamethylcyclotetrasiloxane;

[0052] (A2) nitrogen is introduced, and the mixture in step (A1) is stirred at a vacuum degree of -0.09 MPa and a temperature of 70°C for 60 minutes; then the temperature is raised to 95°C and the reaction is carried out at a vacuum degree of -0.05 MPa for 90 minutes; the temperature is then raised to 104°C, deionized water is added and stirred, and the amount of deionized water added is 1.2% of the total weight of γ-trifluoropropylmethyltrisiloxane and octamethylcyclotetrasiloxane; the reaction is continued for 120 minutes; then the temperature is raised to 160°C and kept warm for 60 minutes; finally, the cyclic small molecule by-products in the reaction system are removed at a vacuum degree of -0.09 MPa to obtain fluorosilicone raw rubber.

[0053] Furthermore, the oil separation aid is methylphenyl silicone oil, CAS No. 63148-58-3, molecular formula C4H 12 OSi.

[0054] Furthermore, the reinforcing filler is white carbon black; the white carbon black is composed of precipitated white carbon black and fumed white carbon black in a weight ratio of 1:2. The precipitated white carbon black is N330 precipitated white carbon black. The fumed white carbon black is Degussa fumed silica white carbon black A200.

[0055] Furthermore, the vulcanizing agent is di-tert-butyl peroxide.

[0056] Furthermore, the preparation method of the synergist includes the following steps: by weight, 18 parts of aluminum silicate, 1.5 parts of dimethylsilyl cage-shaped polysilsesquioxane and 45 parts of ethanol are mixed evenly, then 0.014 parts of potassium hydroxide are added, reacted at a temperature of 55° C. for 4 hours, and then the ethanol is removed by a spray drying method to obtain a synergist.

[0057] Furthermore, the preparation method of the epoxy resin modified silane comprises the following steps: mixing epoxy resin and γ-methacryloxypropyltrimethoxysilane in a molar ratio of 1:2 under the condition of nitrogen, and reacting at 45° C. for 60 minutes to obtain epoxy resin modified silane. The epoxy resin is bisphenol epoxy resin E51.

[0058] This embodiment also provides a method for preparing a self-lubricating vulcanized silicone rubber, comprising the following steps:

[0059] (1) Put methyl vinyl silicone rubber and fluorosilicone rubber into a kneader and stir;

[0060] (2) Under a nitrogen environment, reinforcing filler, hydroxy fluorosilicone oil, epoxy resin modified silane, and synergist are added to a kneader in multiple times, stirring evenly after each addition, and heating to obtain product A;

[0061] (3) After the product A is kneaded and molded, it is cooled, and the oil separation agent is added in four equal amounts, and stirred evenly after each addition; then cerium dioxide is added and mixed evenly to obtain a self-lubricating silicone rubber material;

[0062] (4) The self-lubricating silicone rubber is injected into the mold, a vulcanizing agent is added, and a pressure vulcanization molding is performed, and then it is placed in a blast drying oven for secondary vulcanization to obtain a self-lubricating vulcanized silicone rubber.

[0063] Furthermore, in step (2), the temperature is raised to 155° C., and after hot refining for 120 minutes, vacuuming is performed, and the vacuum degree is -0.08 MPa.

[0064] Furthermore, in step (2), the reinforcing filler, hydroxy fluorosilicone oil, epoxy resin modified silane and synergist are added in three times, each time in the same amount.

[0065] Furthermore, in step (4), the primary vulcanization temperature is 175°C, the pressure is 12 MPa, and the vulcanization time is 6 min; the secondary vulcanization temperature is 200°C, and the vulcanization time is 3 h.

[0066] The present embodiment provides a self-lubricating vulcanized silicone rubber, comprising the following raw materials in parts by weight: 85 parts of base rubber, 12 parts of reinforcing filler, 6 parts of epoxy resin modified silane, 3 parts of hydroxy fluorosilicone oil, 5 parts of oil separation aid, 1.5 parts of cerium dioxide, 5 parts of synergist, and 2 parts of vulcanizer.

[0067] Furthermore, each portion of the base rubber includes 70 portions of methyl vinyl silicone rubber and 15 portions of fluorosilicone rubber.

[0068] Furthermore, the oil separation aid is methylphenyl silicone oil.

[0069] Furthermore, the reinforcing filler is white carbon black; the white carbon black is composed of precipitated white carbon black and fumed white carbon black in a weight ratio of 1:1.

[0070] Furthermore, the vulcanizing agent is 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane.

[0071] Furthermore, the preparation method of the synergist includes the following steps: by weight, 16 parts of aluminum silicate, 1.3 parts of dimethylsilyl cage-shaped polysilsesquioxane and 42 parts of ethanol are mixed evenly, then 0.012 parts of potassium hydroxide are added, reacting at 60° C. for 3 hours, and then removing the ethanol by spray drying to obtain the synergist.

[0072] Furthermore, the preparation method of the epoxy resin modified silane comprises the following steps: under the condition of nitrogen passing, epoxy resin and γ-methacryloxypropyltrimethoxysilane are mixed in a molar ratio of 1:2, and reacted at 42° C. for 70 minutes to obtain epoxy resin modified silane.

[0073] This embodiment also provides a method for preparing a self-lubricating vulcanized silicone rubber, comprising the following steps:

[0074] (1) Put methyl vinyl silicone rubber and fluorosilicone rubber into a kneader and stir;

[0075] (2) Under a nitrogen environment, reinforcing filler, hydroxy fluorosilicone oil, epoxy resin modified silane, and synergist are added to a kneader in multiple times, stirring evenly after each addition, and heating to obtain product A;

[0076] (3) After the product A is kneaded and molded, it is cooled, and the oil separation agent is added in four equal amounts, and stirred evenly after each addition; then cerium dioxide is added and mixed evenly to obtain a self-lubricating silicone rubber material;

[0077] (4) The self-lubricating silicone rubber is injected into the mold, a vulcanizing agent is added, and a pressurized vulcanization molding is performed, and then it is placed in hot air for secondary vulcanization to obtain a self-lubricating vulcanized silicone rubber.

[0078] Furthermore, in step (2), the temperature is raised to 150° C., and after hot refining for 150 minutes, vacuuming is performed, and the vacuum degree is -0.05 MPa.

[0079] Furthermore, in step (2), the reinforcing filler, hydroxy fluorosilicone oil, epoxy resin modified silane and synergist are added in three times, each time in the same amount.

[0080] Furthermore, in step (4), the primary vulcanization temperature is 170°C, the pressure is 14 MPa, and the vulcanization time is 10 min; the secondary vulcanization temperature is 200°C, and the vulcanization time is 3 h.

[0081] The rest of the content of this embodiment is the same as that of Embodiment 1 and will not be repeated here.

[0082] The present embodiment provides a self-lubricating vulcanized silicone rubber, comprising the following raw materials in parts by weight: 85 parts of base rubber, 18 parts of reinforcing filler, 8 parts of epoxy resin modified silane, 4 parts of hydroxy fluorosilicone oil, 6 parts of oil separation aid, 2 parts of cerium dioxide, 8 parts of enhancer, and 4 parts of vulcanizer.

[0083] Furthermore, each portion of the base rubber includes 65 portions of methyl vinyl silicone rubber and 20 portions of fluorosilicone rubber.

[0084] Furthermore, the oil separation aid is methylphenyl silicone oil.

[0085] Furthermore, the reinforcing filler is white carbon black; the white carbon black is composed of precipitated white carbon black and fumed white carbon black in a weight ratio of 1:1.5.

[0086] Furthermore, the vulcanizing agent is di-tert-butyl peroxide.

[0087] Furthermore, the preparation method of the epoxy resin modified silane comprises the following steps: under the condition of nitrogen passing, epoxy resin and γ-methacryloxypropyltrimethoxysilane are mixed in a molar ratio of 1:2, and reacted at a temperature of 50° C. for 60 minutes to obtain epoxy resin modified silane.

[0088] This embodiment also provides a method for preparing a self-lubricating vulcanized silicone rubber, comprising the following steps:

[0089] (1) Put methyl vinyl silicone rubber and fluorosilicone rubber into a kneader and stir;

[0090] (2) Under a nitrogen environment, reinforcing filler, hydroxy fluorosilicone oil, epoxy resin modified silane, and synergist are added to a kneader in multiple times, stirring evenly after each addition, and heating to obtain product A;

[0091] (3) After the product A is kneaded and molded, it is cooled, and the oil separation agent is added in four equal amounts, and stirred evenly after each addition; then cerium dioxide is added and mixed evenly to obtain a self-lubricating silicone rubber material;

[0092] (4) The self-lubricating silicone rubber is injected into the mold, a vulcanizing agent is added, and a pressurized vulcanization molding is performed, and then it is placed in hot air for secondary vulcanization to obtain a self-lubricating vulcanized silicone rubber.

[0093] Furthermore, in step (2), the temperature is raised to 160° C., and after hot refining for 100 minutes, vacuuming is performed, and the vacuum degree is -0.09 MPa.

[0094] Furthermore, in step (2), the reinforcing filler, hydroxy fluorosilicone oil, epoxy resin modified silane and synergist are added in three times, each time in the same amount.

[0095] The rest of the content of this embodiment is the same as that of Embodiment 1 and will not be repeated here.

[0096] Comparative Example 1

[0097] The difference between this comparative example and Example 1 is that the vulcanized silicone rubber in this comparative example does not contain fluorosilicone rubber, and an equal amount of methyl vinyl silicone rubber is used instead. The rest of the contents of this comparative example are the same as those of Example 1, and will not be repeated here.

[0098] Comparative Example 2

[0099] The difference between this comparative example and Example 1 is that the vulcanized silicone rubber provided in this comparative example does not contain epoxy resin modified silane, and an equal amount of methyl vinyl silicone rubber is used instead. The rest of the contents of this comparative example are the same as those of Example 1, and will not be repeated here.

[0100] Comparative Example 3

[0101] The difference between this comparative example and Example 1 is that the vulcanized silicone rubber provided in this comparative example does not contain a synergist. The rest of the contents of this comparative example are the same as those of Example 1 and will not be repeated here.

[0102] The self-lubricating vulcanized silicone rubbers prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to performance tests, and the test results are shown in Table 1 below:

[0103] project hardness Tear strength / Mpa Tensile strength / Mpa Elongation at break / % Compression set performance / % (22h / 177 ℃ ) Example 1 34 22 9.3 590 13 Example 2 33 20 9.4 570 18 Example 3 34 23 9.1 600 17 Comparative Example 1 32 19 8.6 550 21 Comparative Example 2 34 18 7.9 580 19 Comparative Example 3 34 16 7.1 610 24

[0104] The self-lubricating vulcanized silicone rubber obtained in Examples 1-3 and Comparative Examples 1-3 was placed in IRM903 oil for 72 hours at a temperature of 150° C., and the performance was measured:

[0105] project hardness Tear strength change rate / % Change rate of elongation at break / % Example 1 -9 -21 -13 Example 2 -8 -27 -16 Example 3 -11 -24 -17 Comparative Example 1 -13 -31 -23 Comparative Example 2 -9 -25 -19 Comparative Example 3 -14 -28 -21

[0106] Among them, the hardness is tested with reference to GB / T531.1-2008. The tear strength is tested with reference to GB / T 529-2008. The tensile strength and elongation at break are tested with reference to GB / T528-2009. The compression permanent deformation performance is tested with reference to GB / T7759-2015.

[0107] From the above content, it can be seen that the self-lubricating vulcanized silicone rubber of the present invention is prepared by combining fluorosilicone raw rubber and methyl vinyl silicone rubber as base rubber, and combining with epoxy resin modified silane, enhancer and other raw materials, so that the prepared vulcanized silicone rubber has good heat stability, oil resistance and mechanical properties, and has the characteristics of low compression permanent deformation. It can be used in technical fields such as automotive wiring harness sealing and mechanical dynamic sealing, has good sealing performance, long service life and wide application range.

[0108] The above specific embodiments are further explanations of the technical solutions and beneficial effects of the present invention, and are not limitations of the implementation methods. For those skilled in the art, any obvious replacements that do not depart from the concept of the present invention are within the protection scope of the present invention.

Claims

1. A self-lubricating vulcanized silicone rubber, characterized in that: The raw materials include the following parts by weight: 80-90 parts of base rubber, 10-20 parts of reinforcing filler, 5-10 parts of epoxy resin modified silane, 2-5 parts of hydroxy fluorosilicone oil, 4-10 parts of oil separation aid, 1-2 parts of cerium dioxide, 4-8 parts of synergist, and 1-5 parts of vulcanizer; each part of the base rubber includes 65-75 parts of methyl vinyl silicone rubber and 15-25 parts of fluorosilicone raw rubber; The preparation method of the synergist comprises the following steps: taking 15-20 parts of aluminum silicate, 1-2 parts of dimethylsilyl cage-shaped polysilsesquioxane and 40-50 parts of ethanol by weight, mixing them evenly, then adding 0.01-0.015 parts of potassium hydroxide, reacting at a temperature of 50-60° C. for 3-5 hours, and then removing the ethanol to obtain the synergist; The preparation method of the epoxy resin modified silane comprises the following steps: mixing epoxy resin and γ-methacryloxypropyltrimethoxysilane at a molar ratio of 1:1.5-3 under the condition of nitrogen gas, and reacting at a temperature of 40-50° C. for 60-90 minutes to obtain the epoxy resin modified silane.

2. The self-lubricating vulcanized silicone rubber according to claim 1, characterized in that: The oil separation aid is at least one of methylphenyl silicone oil and diphenyl silicone oil.

3. The self-lubricating vulcanized silicone rubber according to claim 1, characterized in that: The reinforcing filler is white carbon black.

4. The self-lubricating vulcanized silicone rubber according to claim 1, characterized in that: The vulcanizing agent is at least one of di-tert-butyl peroxide, diisopropylbenzene peroxide, 2,5-dimethyl-2,5-di-tert-butylperoxyhexane and bis(2,4-dichlorobenzoyl)peroxide.

5. The method for preparing the self-lubricating vulcanized silicone rubber according to any one of claims 1 to 4, characterized in that: The steps include: (1) Put the base rubber into a kneader and stir; (2) Under a nitrogen environment, reinforcing filler, hydroxy fluorosilicone oil, epoxy resin modified silane, and synergist are added to a kneader in multiple times, stirring evenly after each addition, and heating to obtain product A; (3) After the product A is kneaded and molded, it is cooled, and the oil separation agent is added in multiple times, and stirred evenly after each addition; then cerium dioxide is added and mixed evenly to obtain a self-lubricating silicone rubber material; (4) The self-lubricating silicone rubber is injected into the mold, a vulcanizing agent is added, and a primary vulcanization molding is performed, and then it is placed in hot air for secondary vulcanization to obtain a self-lubricating vulcanized silicone rubber.

6. The method for preparing the self-lubricating vulcanized silicone rubber according to claim 5, characterized in that: In step (2), the temperature is raised to 150-160°C, and after hot refining for 90-150 minutes, vacuuming is performed, and the vacuum degree is (-0.05)-(-0.09) MPa.

7. The method for preparing the self-lubricating vulcanized silicone rubber according to claim 5, characterized in that: In step (4), the primary vulcanization temperature is 170-180°C, and the vulcanization time is 5-10 minutes; the secondary vulcanization temperature is 180-210°C, and the vulcanization time is 2-4 hours.