Silicone rubber and preparation method thereof

Abstract

The invention relates to the field of silicone rubber, in particular to silicone rubber and a preparation method thereof. The silicone rubber is prepared from the following components in parts by mass: 100 parts of methyl vinyl silicone rubber raw rubber, 40 to 60 parts of white carbon black, 3 to 12 parts of a structured control agent, 0.3 to 2.0 parts of hydrogen-containing silicone oil, 0.1 to 4.0 parts of polyvinyl silicone oil, 0.3 to 0.5 part of deionized water, 0.01 to 0.5 part of an internal release agent, 0.5 to 5 parts of black color masterbatch, 0.5 to 10 parts of a heat-resistant agent and 0.5 to 2 parts of a vulcanizing agent. The silicone rubber has the advantages of excellent high temperature resistance, low pressure change, oil resistance and good comprehensive performance.

Description

Technical Field

[0001] The present invention relates to the field of silicone rubber, and more specifically, to silicone rubber and a preparation method thereof. Background Art

[0002] Silicone rubber has been widely used in many industries, such as the automotive industry, wire and cable, electronics industry, aerospace, and medical and health fields, due to its excellent high temperature resistance, cold resistance, weather resistance, and electrical insulation performance. In the automotive industry, silicone rubber is an ideal material for the key component of the ignition coil. The performance of the ignition coil directly affects the ignition strength of the spark plug, thereby determining the combustion efficiency of the engine. Considering that the ignition coil will not only receive heat conduction from the engine when working, but also generate heat due to its own work, extremely high requirements are placed on the high temperature resistance of silicone rubber. If the sealing effect is not good, it will affect the ignition effect, so a certain compression permanent deformation performance is required. The spark plug and the ignition coil will contact oil, so it is also required to have a certain oil resistance. Traditional silicone rubber materials may encounter difficulties in demolding, and the injection port is prone to fracture, which poses a challenge to both production efficiency and product quality. At the same time, customers also have high requirements for the appearance of the sheath silicone rubber, usually expecting it to be black. In order to meet these complex and stringent requirements, it is particularly important to develop a silicone rubber material that is resistant to high temperature, low pressure change, oil resistance, and has good comprehensive performance. This will not only help improve the performance of traditional vehicles, but will also play a key role in the new energy vehicle market.

[0003] Among the silicone rubber patents with more prior art disclosures, there are many related existing technologies involving "high temperature resistance", "low pressure change" or "oil resistance", but the vast majority of prior art only includes one of these characteristics, there are very few prior art involving two characteristics, and there is no prior art involving the above three characteristics. Based on the shortcomings of the prior art, the purpose of the present invention is to provide a high temperature resistant, low pressure change, oil resistant silicone rubber and its preparation method, and optimize the appearance and demolding properties of the rubber material, so that silicone rubber can be widely used in the automotive industry. Summary of the invention

[0004] In order to solve the above technical problems, the present invention provides a silicone rubber, which is composed of the following components in parts by weight: 100 parts of methyl vinyl silicone rubber raw rubber, 40-60 parts of white carbon black, 3-12 parts of structuring control agent, 0.3-2.0 parts of hydrogenated silicone oil, 0.1-4.0 parts of polyvinyl silicone oil, 0.3-0.5 parts of deionized water, 0.01-0.5 parts of internal release agent, 0.5-5 parts of black masterbatch, 0.5-10 parts of heat resistant agent and 0.5-2 parts of vulcanizing agent.

[0005] Furthermore, the molar mass of the methyl vinyl silicone rubber raw rubber is between 500,000 and 750,000 g / mol, and the content of vinyl in the methyl vinyl silicone rubber raw rubber is 0.05-0.4% in molar percentage.

[0006] Furthermore, the white carbon black is fumed white carbon black.

[0007] Furthermore, the white carbon black has a specific surface area of ​​150-350m 2 / g of silica.

[0008] Furthermore, the structuring control agent includes one or more of hydroxy silicone oil, vinyl hydroxy silicone oil, diphenyl dihydroxy silicone oil, dimethyldimethoxysilane, dimethyldiethoxysilane, methylphenyldimethoxysilane, hexamethyldisilazane, vinylsilazane, vinyltrimethoxysilane, vinyltriethoxysilane and active silicone oil.

[0009] Furthermore, the hydrogen content of the hydrogen-containing silicone oil is between 0.36% and 1.6% by mass, and the viscosity is 50-100 mm 2 / s.

[0010] Furthermore, the polyvinyl silicone oil is a methyl-terminated methyl vinyl silicone oil with a viscosity of 2500-10000 mm 2 / s, vinyl content 8.0-15.0%.

[0011] Furthermore, the internal mold release agent is one or more of zinc stearate, calcium stearate, barium stearate, magnesium stearate, zinc laurate, magnesium laurate, palmitic acid, polyethylene glycol distearate, lauric acid, and stearic acid.

[0012] Furthermore, the heat-resistant agent is one or two of cerium oxide, iron oxide, zirconium oxide, titanium dioxide, yttrium oxide, carbon black, etc.

[0013] Furthermore, the vulcanizing agent is one or more of 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane (C-6A, C-6B, C-8A, C-8B, etc.), dicumyl peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide or platinum vulcanizing agent.

[0014] Furthermore, the black masterbatch is a mixture of carbon black pigment in the blue phase and methyl vinyl silicone rubber raw rubber, wherein the effective content of the carbon black pigment is 30-50% by mass;

[0015] Furthermore, the blue-phase carbon black pigment in the black masterbatch is in the form of a fluffy powder with a volume density of 120-380 kg / m3;

[0016] Furthermore, the methyl vinyl silicone rubber raw rubber in the black masterbatch is a methyl vinyl silicone rubber raw rubber with a vinyl content of 0.05-0.25% and a molecular weight of 650000-750000 g / mol.

[0017] Furthermore, the mixing ratio of the pigment carbon black and the methyl vinyl silicone rubber raw rubber in the black masterbatch is 3:7-5:5, and the black masterbatch is ground by a three-roll grinder for 10-15 times.

[0018] On the other hand, a method for preparing silicone rubber is also provided, comprising:

[0019] Mixing methyl vinyl silicone rubber, part of the structure control agent and deionized water in a kneader to obtain a first mixed material;

[0020] Add the remaining structure control agent, hydrogen-containing silicone oil, polyvinyl silicone oil, internal mold release agent, and white carbon black to the first mixed material, mix well, and obtain a second mixed material;

[0021] The second mixed material is kneaded to obtain a mixed base rubber, and the mixed base rubber is mixed with a heat-resistant agent and a black masterbatch, and the silicone rubber is obtained after mixing.

[0022] Further, the preparation conditions of the first mixture are 10-30 min;

[0023] Furthermore, the second mixed material is prepared under the conditions of mixing at a temperature of 100° C. and standing for 4-8 hours;

[0024] Furthermore, the banburying conditions are 0.04-0.08MPa, temperature 120-170°C, 2-5h;

[0025] Furthermore, the mixing base rubber, the heat-resistant agent and the black masterbatch are mixed at a temperature ranging from room temperature to 100°C.

[0026] Beneficial effects of this patent:

[0027] 1. The silicone rubber prepared by the present invention has excellent high temperature resistance, low pressure change, oil resistance and good comprehensive performance.

[0028] 2. The present invention uses a heat-resistant agent and a black masterbatch in combination, which can effectively improve the heat and oil resistance of silicone rubber and have a synergistic effect on the heat and oil resistance of silicone rubber. The heat-resistant agent, as a heat stabilizer, can inhibit the degradation of the main chain of silicone rubber and the oxidation of the side groups. When the heat-resistant agent is used, the heat-resistant agent has a certain lipophilicity and adsorption property, and can adsorb and fix the oil and solvent molecules in the silicone rubber, reducing their migration and diffusion in the silicone rubber. The black masterbatch provides a stable and uniform black color for the silicone rubber, and by changing the surface properties of the silicone rubber or increasing the surface roughness, it will affect the adhesion and penetration behavior of oil and solvent on the silicone rubber surface, improve oil resistance, and is particularly suitable for the manufacture of key automotive parts such as ignition coil sheaths.

[0029] 3. The present invention accelerates the vulcanization speed and improves the crosslinking density by using a high content vulcanizing agent and adding hydrogen-containing silicone oil. Even without the second stage baking, it can have good performance, significantly improve the compression permanent deformation and oil resistance of silicone rubber, and accelerate the vulcanization speed to improve the demoulding efficiency. On the basis of maintaining excellent sealing performance, this material has a significant positive effect on improving the ignition efficiency of key components such as spark plugs.

[0030] 4. The black masterbatch used in the present invention is a powdered medium-pigment carbon black with a blue base phase, which is highly dispersible and can provide high-blackness black coloring for silicone rubber. The color paste is effectively ground and crushed by a three-roll grinder to form a pigment carbon black with a smaller particle size. When added to silicone rubber, it is easier to color, and the blackness stability is also better after high-temperature baking.

[0031] Other features and advantages of the present invention will be described in the following description, and partly become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the description, claims, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings are used to provide a further understanding of the technical solution of the present invention and constitute a part of the specification. Together with the embodiments of the present application, they are used to explain the technical solution of the present invention and do not constitute a limitation on the technical solution of the present invention.

[0033] Figure 1 This is a comparison diagram of the rubber compound added with carbon black in Example 5 of the present invention after secondary vulcanization and aging at 275°C*70h;

[0034] Figure 2 This is a comparison chart of the rubber material of comparative example 3 of the present invention with iron black added after secondary vulcanization and aging at 275°C*70h. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiment of the present invention clearer, the technical solution of the embodiment of the present invention will be clearly and completely described in conjunction with the appendix of the specific embodiment of the present invention. Obviously, the described embodiment is a part of the embodiment of the present invention, not all of the embodiments. Based on the described embodiment of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] The embodiment of the present invention provides a silicone rubber, which is mainly composed of the following components in parts by weight:

[0037] 100 parts of methyl vinyl silicone rubber;

[0038] 40-60 parts of white carbon black;

[0039] 0.4-12 parts of structure control agent;

[0040] 0.3-2.0 parts of hydrogen silicone oil;

[0041] Polyvinyl silicone oil 0.1-4.0 parts;

[0042] 0.3-2.5 parts of deionized water;

[0043] Internal release agent 0.01-0.5 parts;

[0044] Black masterbatch (i.e. carbon black masterbatch) 0.5-5 parts;

[0045] Heat-resistant agent 0.5-10 parts;

[0046] Vulcanizing agent 0.5-2 parts.

[0047] The high temperature resistant, low pressure change and oil resistant silicone rubber produced by the above scheme can meet various demands of the automotive industry for silicone rubber.

[0048] In another embodiment of the present invention, the molar mass of the methyl vinyl silicone rubber raw rubber is between 500000-750000 g / mol, wherein the content of vinyl groups is 0.05-0.4% in molar percentage.

[0049] In another embodiment of the present invention, the reinforcing silica is fumed silica, which is silicon dioxide with a specific surface area of ​​150-350 m2 / g. More preferably, the specific surface area is 175-330 m2 / g.

[0050] In another embodiment of the present invention, the structuring control agent includes one or more of hydroxy silicone oil, vinyl hydroxy silicone oil, diphenyl dihydroxy silicone oil, dimethyldimethoxysilane, dimethyldiethoxysilane, methylphenyldimethoxysilane, hexamethyldisilazane, vinylsilazane, vinyltrimethoxysilane, vinyltriethoxysilane and active silicone oil.

[0051] In another embodiment of the present invention, the hydrogen content (wt%) of the hydrogen-containing silicone oil is between 0.36% and 1.6%, and the viscosity is 50-100 mm2 / s.

[0052] In another embodiment of the present invention, the polyvinyl silicone oil is a methyl-terminated methyl vinyl silicone oil with a viscosity of 2500-10000 mm2 / s and a vinyl content of 8.0-15.0%.

[0053] When the above parameters are not within the above ranges, the hardness and strength of the obtained silicone rubber are poor.

[0054] In another embodiment of the present invention, the internal mold release agent is one or more of zinc stearate, calcium stearate, barium stearate, magnesium stearate, zinc laurate, magnesium laurate, palmitic acid, polyethylene glycol distearate, lauric acid, and stearic acid.

[0055] In another embodiment of the present invention, the black masterbatch is a mixture of pigment carbon black in the blue phase and methyl vinyl silicone rubber raw rubber, and the masterbatch is effectively ground and crushed by a three-roll grinder to form pigment carbon black with smaller particle size, and the effective content of the pigment carbon black is 30-50%.

[0056] In another embodiment of the present invention, the carbon black pigment in the blue phase of the black masterbatch is in the form of fluffy powder with a volume density of 120-380 kg / m3.

[0057] In another embodiment of the present invention, the methyl vinyl silicone rubber raw rubber in the black masterbatch is a methyl vinyl silicone rubber raw rubber with a vinyl content of 0.05-0.25% and a molecular weight of 650000-750000 g / mol.

[0058] In another embodiment of the present invention, the mixing ratio of the pigment carbon black and the methyl vinyl silicone rubber raw rubber in the black masterbatch is 3:7-5:5, and the black masterbatch is ground by a three-roll grinder for 10-15 times.

[0059] In another embodiment of the present invention, the heat-resistant agent is one or more of cerium oxide, iron oxide, zirconium oxide, titanium dioxide, yttrium oxide, and carbon black, which are commercially available heat-resistant agents.

[0060] In another embodiment of the present invention, the vulcanizing agent is one of 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane (C-6A, C-6B, C-8A, C-8B, etc.), diisopropylbenzene peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide or platinum vulcanizing agent.

[0061] The present invention also relates to a method for preparing high temperature resistant, low pressure change and oil resistant silicone rubber, comprising the following steps:

[0062] (1) Put methyl vinyl silicone rubber, part of the structure control agent and deionized water into a kneader and mix for 10-30 minutes to obtain a first mixed material.

[0063] (2) Add other structural control agents, hydrogenated silicone oil, polyvinyl silicone oil, internal mold release agent and white carbon black to the first mixed material. Add the additives to the first mixed material, add white carbon black to the first mixed material in batches, mix evenly at 100° C., and leave for 4-8 hours to obtain a second mixed material.

[0064] (3) The second mixed material is kneaded at 0.04-0.08 MPa and 120-170°C for 2-5 hours to obtain a mixed base rubber. The mixed base rubber is mixed with a heat-resistant agent and a black masterbatch at room temperature to 100°C. After mixing, a vulcanizing agent is added and the material is discharged.

[0065] In order to more clearly illustrate the present invention, the following examples and comparative examples are provided for description.

[0066] The "parts" in the following embodiments are "parts by weight". The measurement units of "parts" or "parts by weight" in the same embodiment are unified, which is the same as the idea of ​​the technical solution defined by specific measurement units and does not affect its feasibility.

[0067] Unless otherwise specified, "%" means molar percentage "mol %" in relation to the vinyl content.

[0068] Example 1

[0069] 100 parts of methyl vinyl silicone rubber raw rubber with an average molecular weight of 693,000 and an average vinyl content of 0.146 mol% (including 95.0 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 700,000 and a vinyl content of 0.08 mol%, 4.0 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 560,000 and a vinyl content of 1.0 mol%, and 1.0 part of methyl vinyl silicone rubber raw rubber with a molecular weight of 550,000 and a vinyl content of 3.0 mol%), 1.0 part of hexamethyldisilazane (refractive index (20°C): 1.4069-1.4089), and 0.3 parts of deionized water are added into a kneader and mixed for 30 minutes to obtain a first mixed material. 2.0 parts of vinyl hydroxy silicone oil (viscosity (25°C): 35 mm2 / s, hydroxyl content: (wt%) 6.0, vinyl content: (mol%) 7.0), 0.2 parts of polyvinyl silicone oil (viscosity: 10000 mm2 / s, vinyl content: (mol%) 8.0), 5.0 parts of hydroxy silicone oil (viscosity at 25°C is 25 mm2 / s, hydroxyl content is 8.5 wt%), 0.8 parts of hydrogen silicone oil (viscosity (25°C): 80 mm2 / s, vinyl content is 10. Hydrogen content: (wt%) 0.6), 0.07 parts of palmitic acid (Nanjing Dongde Chemical Technology Co., Ltd.), 46 parts of fumed silica (T200H, specific surface area: 220±10m2 / g, Xinjiang Jingshuo) were added in batches according to 16 parts, 12 parts, 10 parts, 4 parts, 2 parts, and 2 parts. The components were kneaded at 100°C, the rubber was discharged, and the rubber was divided into blocks. The second mixed material was stored for 4 hours to obtain the second mixed material. The second mixed material was subjected to high temperature at 0.06MPa and about 160°C. Mix at warm temperature for 3 hours, keep warm, remove low molecular weight substances, and wait until the rubber compound cools to 50°C. Add 1.0 part of Wacker heat resistant agent H3 (heat resistant carbon black) and 2.0 parts of carbon black masterbatch (HIBLACK890, Orion, mixed with methyl vinyl silicone rubber with a vinyl content of 0.08% and a molecular weight of 700000 g / mol in a ratio of 2:3, and grind it 12 times on a three-roll mill). Continue kneading (cooling water is required, the temperature is 100°C) for 20 minutes, then discharge the material and divide the rubber compound into sheets. The rubber material was cooled for more than 30 minutes, and then it was open-mixed, filtered, weighed, and packaged to obtain a rubber mix. 100 parts of the rubber mix were mixed and dispersed with 1.0 part of 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane (C-6B) using a 150mm open mill, and a curable silicone rubber composition was prepared after being completely thinned. The curable silicone rubber composition was subjected to plate vulcanization at 170°C for 10 minutes, i.e., primary vulcanization, and also post-vulcanization at 200°C for 2 hours, i.e., secondary vulcanization, and its mechanical properties were tested.

[0070] Example 2

[0071] 100 parts of methyl vinyl silicone rubber raw rubber with an average molecular weight of 699,000 and an average vinyl content of 0.162 mol% (including 38 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 720,000 and a vinyl content of 0.03 mol%, 56 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 700,000 and a vinyl content of 0.09 mol%, 4.0 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 560,000 and a vinyl content of 1.0 mol%, and 2.0 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 550,000 and a vinyl content of 3.0 mol%), 1.1 parts of hexamethyldisilazane (refractive index (20°C): 1.4069-1.4089), and 0.3 parts of deionized water were added into a kneader and mixed for 30 minutes to obtain a first mixture. 0.8 parts of vinyl hydroxy silicone oil (viscosity (25°C), mm2 / s: 35, hydroxyl content: (wt%) 6.0, vinyl content: (mol%) 7.0), 0.3 parts of polyvinyl silicone oil (viscosity, mm2 / s: 10000, vinyl content: (mol%) 8.0), 6.5 parts of hydroxy silicone oil (viscosity at 25°C is 25 mm2 / s, hydroxyl content is 8.5 wt%), 1.0 parts of hydrogen-containing silicone oil (viscosity (25°C), mm2 / s: 80, hydrogen content: (wt%) 0.6), 0.1 parts of calcium stearate (Hangzhou Oil Chemical Co., Ltd.), 45 parts of fumed silica (A200, 220±25m2 / g, Evonik Degussa) were added in batches of 15 parts, 12 parts, 10 parts, 4 parts, 2 parts, and 2 parts. At 100°C, knead all the components, discharge the rubber, divide the rubber into blocks, and store it for 4 hours to obtain the second mixed material. The second mixed material is subjected to high-temperature banburying at 0.07MPa and about 165°C for 3 hours, heat preservation, and removal of low molecular weight substances, and the rubber is cooled to below 100°C. Add 1.5 parts of Wacker heat-resistant agent H3 and 1.5 parts of carbon black masterbatch (Cabot M800 and methyl vinyl silicone rubber with a vinyl content of 0.05% and a molecular weight of 730000g / mol are mixed in a ratio of 2:3, and ground 14 times by a three-roll grinder), continue to knead (cooling water is required, and the temperature cannot exceed 100°C) for 20 minutes, discharge the material, divide the rubber into sheets, cool for more than 30 minutes, open-mix, filter, weigh, and package to obtain a mixed rubber. 100 parts of the rubber mix were mixed and dispersed with 0.6 parts of 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane (C-8A) using a 150 mm open mill, and a curable silicone rubber composition was prepared after complete thinning. The curable silicone rubber composition was subjected to plate vulcanization at 170°C for 10 minutes, i.e., primary vulcanization, and also to post-vulcanization at 200°C for 2 hours, i.e., secondary vulcanization, and its mechanical properties were tested.

[0072] Example 3

[0073] 100 parts of methyl vinyl silicone rubber raw rubber with an average molecular weight of 691,000 and an average vinyl content of 0.167 mol% (including 49 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 700,000 and a vinyl content of 0.08 mol%, 24 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 690,000 and a vinyl content of 0.16 mol%, 26 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 680,000 and a vinyl content of 0.23 mol%, and 1 part of methyl vinyl silicone rubber raw rubber with a molecular weight of 550,000 and a vinyl content of 3.0 mol%), 1.0 part of hexamethyldisilazane (refractive index (20°C): 1.4069-1.4089), and 0.3 parts of deionized water are added into a kneader and mixed for 20 minutes to obtain a first mixed material. 1.0 part of vinyl hydroxy silicone oil (viscosity (25°C), mm2 / s: 35, hydroxyl content: (wt%) 6.0, vinyl content: (mol%) 7.0), 0.4 part of polyvinyl silicone oil (viscosity, mm2 / s: 10000, vinyl content: (mol%) 8.0), 6.8 parts of hydroxy silicone oil (viscosity at 25°C is 25 mm2 / s, hydroxyl content is 8.5 wt%), 0.8 part of dimethyldimethoxysilane (refractive index: 1.369-1.371, purity: 99%, Hubei Co-Formula) Materials Technology Co., Ltd.), 0.7 parts of hydrogenated silicone oil (viscosity (25°C), mm2 / s: 80, hydrogen content: (wt%) 0.6), 0.08 parts of stearic acid (Hangzhou Oil Chemical Co., Ltd.), 46 parts of fumed silica (XHG-300, 280-330m2 / g, Zhejiang Kaihua Synthetic Materials Co., Ltd.) were added in batches of 15 parts, 13 parts, 11 parts, 4 parts, 2 parts, and 1 part, and the components were kneaded at 100°C, the rubber was discharged, and the rubber was divided into blocks, and then stored for 5 hours to obtain the second mixed material. The second mixed material was subjected to high-temperature banburying at 0.05MPa and about 170°C for 2 hours, heat preservation, removal of low molecular weight substances, and the rubber was cooled to below 100°C. Add 2.0 parts of Wacker heat resistant agent H3 and 1.0 parts of carbon black masterbatch (Cabot M900 and methyl vinyl silicone rubber with a vinyl content of 0.05% and a molecular weight of 730000 g / mol in a ratio of 3:7, and grind it 12 times on a three-roll mill), continue kneading (cooling water is required, and the temperature cannot exceed 100°C) for 20 minutes, then discharge the material, divide the rubber into sheet rubber, cool it for more than 30 minutes, and perform open mixing, filter the rubber, weigh it, and package it to obtain a mixed rubber. Take 100 parts of the mixed rubber, mix and disperse 0.6 parts of 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane (C-8A) with a 150mm open mixing mill, and after passing it through the thin mill, a curable silicone rubber composition is prepared. The curable silicone rubber composition is subjected to plate vulcanization at 170°C for 10 minutes, i.e., primary vulcanization, and also subjected to post-vulcanization at 200°C for 2 hours, i.e., secondary vulcanization, and its mechanical properties are tested.

[0074] Example 4

[0075] 100 parts of methyl vinyl silicone rubber raw rubber with an average molecular weight of 702,000 and an average vinyl content of 0.154 mol% (including 78 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 710,000 and a vinyl content of 0.08 mol%, 21 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 680,000 and a vinyl content of 0.20 mol%, and 1.0 part of methyl vinyl silicone rubber raw rubber with a molecular weight of 530,000 and a vinyl content of 5.0 mol%), 1.0 part of hexamethyldisilazane (refractive index (20°C): 1.4069-1.4089), and 0.3 parts of deionized water were added into a kneader for 10 minutes to obtain a first mixed material, and 1.0 part of vinyl hydroxy silicone oil (viscosity (25°C), mm2 / s: 35, hydroxyl content: (wt%) 6.0, vinyl content: (mol%) 7.0), 0.1 part of polyvinyl silicone oil (viscosity, mm2 / s: 10000, vinyl content: (mol%) %) 8.0), 6.3 parts of hydroxy silicone oil (viscosity at 25℃ is 25mm2 / s, hydroxyl content is 8.5wt%), 1.0 parts of dimethyldimethoxysilane (refractive index: 1.369-1.371, purity: 99%, Hubei Kefula Material Technology Co., Ltd.), 0.8 parts of hydrogen-containing silicone oil (viscosity (25℃), mm2 / s: 80, hydrogen content: (wt%) 0.6), 0.08 parts of polyethylene glycol distearate (Nantong Qianhe Chemical Co., Ltd. Company), 46 parts of fumed silica (HL-200, 200±20m2 / g, Yichang Huifu Silicon Material Co., Ltd.) were added in batches according to 14 parts, 13 parts, 9 parts, 5 parts, 3 parts and 2 parts. The components were kneaded at 100°C, the rubber was discharged, and the rubber was divided into blocks. The mixture was allowed to stand for 5 hours to obtain a second mixed material. The second mixed material was subjected to high-temperature mixing, heat preservation and removal of low-molecular substances at 0.06MPa and about 165°C, and the rubber was cooled to 30°C. 1.5 parts of Wacker heat-resistant agent H6 and 2.5 parts of carbon black masterbatch (BC2000 (Tianjin Baochi Chemical Technology Co., Ltd.), mixed with methyl vinyl silicone rubber with a vinyl content of 0.23% and a molecular weight of 680000 g / mol in a ratio of 5:5, and ground 12 times by a three-roll grinder) were added, and the mixture was discharged after 20 minutes of continuous kneading (cooling water was required, the temperature was 80°C), and the rubber was divided into sheet rubber, cooled for more than 30 minutes, and then opened, filtered, weighed, and packaged to obtain a mixed rubber. 100 parts of the mixed rubber were taken, and 0.6 parts of 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane (C-8A) was mixed and dispersed on a 150mm open mill, and a curable silicone rubber composition was prepared after thinning was completely passed. The curable silicone rubber composition was subjected to plate vulcanization at 155°C for 10 minutes, i.e., primary vulcanization, and post-vulcanization at 200°C for 2 hours, i.e., secondary vulcanization, and its mechanical properties were tested.

[0076] Example 5

[0077] 100 parts of methyl vinyl silicone rubber with an average molecular weight of 706,000 and an average vinyl content of 0.160 mol% (including 21 parts of methyl vinyl silicone rubber with a molecular weight of 730,000 and a vinyl content of 0.05 mol%, 74 parts of methyl vinyl silicone rubber with a molecular weight of 710,000 and a vinyl content of 0.08 mol%, 3.0 parts of methyl vinyl silicone rubber with a molecular weight of 530,000 and a vinyl content of 1.0 mol%, and 2.0 parts of methyl vinyl silicone rubber with a molecular weight of 550,000 and a vinyl content of 3.0 mol%), 2.0 parts of hexamethyldisilazane (refractive index (20°C): 1.4069-1.4089), and 0.5 parts of deionized water were added into a kneader and mixed for 30 minutes to obtain a first mixed material; 0.9 parts of vinyl hydroxy silicone oil (viscosity (25°C), mm2 / s: 3 5, hydroxyl content: (wt%) 6.0, vinyl content: (mol%) 7.0), 0.1 part of polyvinyl silicone oil (viscosity, mm2 / s: 10000, vinyl content: (mol%) 8.0), 1.0 part of active silicone oil (JP-H34, viscosity at 25°C ≤15mm2 / s, Shenzhen Jipeng Silicon Fluoride Material Co., Ltd.), 1.5 parts of hydroxyl silicone oil (viscosity at 25°C is 25mm2 / s, hydroxyl content is 8.5wt%), 1.3 parts of hydrogen-containing silicone oil (viscosity (25°C), mm2 / s: 80, hydrogen content: (wt%) 0.6), 0.07 part of zinc stearate (Hangzhou Oil Chemical Co., Ltd.), 46 parts of fumed silica (XHG-200, 195-220m2 / g, Zhejiang Kaihua Synthetic Material Co., Ltd.) were added in batches of 15 parts, 13 parts, 9 parts, 4 parts, 3 parts, and 2 parts. At 100°C, knead all the components, discharge the rubber, divide the rubber into blocks, and store it for 8 hours to obtain the second mixed material. The second mixed material is subjected to high-temperature banburying at 0.04MPa and about 170°C for 2 hours, heat preservation, and removal of low molecular weight substances, and the rubber is cooled to 60°C. Add 1.5 parts of Wacker heat-resistant agent H3 and 1.5 parts of carbon black masterbatch (Cabot M880, mixed with methyl vinyl silicone rubber with a vinyl content of 0.08% and a molecular weight of 700000g / mol in a ratio of 2:3, and ground 12 times by a three-roll grinder) and continue to knead (cooling water is required, the temperature is 80°C) for 20 minutes before discharging the material, dividing the rubber into sheets, cooling for more than 30 minutes, and refining, filtering, weighing, and packaging to obtain a mixed rubber. 100 parts of the rubber mix were mixed and dispersed with 0.6 parts of 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane (C-8A) using a 150 mm open mill, and a curable silicone rubber composition was prepared after complete thinning. The curable silicone rubber composition was subjected to plate vulcanization at 170°C for 10 minutes, i.e., primary vulcanization, and also to post-vulcanization at 200°C for 2 hours, i.e., secondary vulcanization, and its mechanical properties were tested.

[0078] Example 6

[0079] 100 parts of methyl vinyl silicone rubber raw rubber with an average molecular weight of 727,000 and an average vinyl content of 0.164 mol% (including 81 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 740,000 and a vinyl content of 0.03 mol%, 18 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 680,000 and a vinyl content of 0.5 mol%, and 1.0 part of methyl vinyl silicone rubber raw rubber with a molecular weight of 500,000 and a vinyl content of 5.0 mol%), 2.0 parts of hexamethyldisilazane (refractive index (20°C): 1.4069-1.4089), and 0.5 parts of deionized water are added into a kneader and mixed for 25 minutes to obtain a first mixed material. 1.0 part of vinyl hydroxy silicone oil (viscosity (25°C), mm2 / s: 35, hydroxyl content: (wt%) 6.0, vinyl content: (mol%) 7.0), 0.2 part of polyvinyl silicone oil (viscosity, mm2 / s: 10000, vinyl content: (mol%) 8.0), 1.5 parts of active silicone oil (JP-H34, viscosity at 25°C ≤15mm2 / s, Shenzhen Jipeng Silicon Fluoride Materials Co., Ltd.), 1.0 part of hydroxy silicone oil (viscosity at 25°C is 25mm2 / s, hydroxyl content is 8.5wt%), 1.0 part of hydrogen-containing silicone oil (viscosity (25℃), mm2 / s: 80, hydrogen content: (wt%) 0.6), 0.1 part of calcium stearate (Hangzhou Oil Chemical Co., Ltd.), 45 parts of fumed silica (HS-200, 185-225m2 / g, Hesheng Silicon Industry Co., Ltd.) were added in batches of 14 parts, 11 parts, 9 parts, 6 parts, 3 parts, and 2 parts, and the components were kneaded at 100℃, the rubber was discharged, and the rubber was divided into blocks, and then stored for 8 hours to obtain the second mixed material. The second mixed material was subjected to high-temperature banburying, heat preservation, and removal of low-molecular substances at 0.08MPa and about 160℃, and the rubber was cooled to room temperature. Add 1.5 parts of Wacker heat-resistant agent H3 and 1.0 parts of carbon black masterbatch (#S4, Mitsubishi, Japan, mixed with methyl vinyl silicone rubber with a vinyl content of 0.16% and a molecular weight of 690000g / mol in a ratio of 1:2, and grinded 10 times by a three-roll mill) and continue kneading (cooling water is required, the temperature is room temperature) for 20 minutes before discharging, the rubber is divided into sheet rubber, cooled for more than 30 minutes, and then open-mixed, filtered, weighed, and packaged to obtain a mixed rubber. Take 100 parts of the mixed rubber, mix and disperse 0.6 parts of 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane (C-8A) with a 150mm open mill, and after thinning completely, a curable silicone rubber composition is prepared. The curable silicone rubber composition is subjected to plate vulcanization at 170°C for 10 minutes, i.e., primary vulcanization, and post-vulcanization at 200°C for 2 hours, i.e., secondary vulcanization, and its mechanical properties are tested.

[0080] Example 7

[0081] 100 parts of methyl vinyl silicone rubber raw rubber with an average molecular weight of 708,000 and an average vinyl content of 0.176 mol% (including 51.5 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 730,000 and a vinyl content of 0.05 mol%, 47 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 690,000 and a vinyl content of 0.16 mol%, and 1.5 parts of methyl vinyl silicone rubber raw rubber with a molecular weight of 500,000 and a vinyl content of 5.0 mol%), 2.0 parts of hexamethyldisilazane (refractive index (20°C): 1.4069-1.4089), and 0.6 parts of deionized water are added into a kneader and mixed for 30 minutes to obtain a first mixed material. 0.8 parts of vinyl hydroxy silicone oil (viscosity (25°C), mm2 / s: 35, hydroxyl content: (wt%) 6.0, vinyl content: (mol%) 7.0), 0.1 parts of polyvinyl silicone oil (viscosity, mm2 / s: 10000, vinyl content: (mol%) 8.0), 2.0 parts of active silicone oil (JP-H34, viscosity at 25°C ≤15mm2 / s, Shenzhen Jipeng Silicon Fluoride Material Co., Ltd.), 1.3 parts of hydroxy silicone oil (viscosity at 25°C is 25mm2 / s, hydroxyl content is 8.5wt%), 1.2 parts of hydrogenated silicone oil (viscosity (25 ℃), mm2 / s: 80, hydroxyl content: (wt%) 0.6), 0.09 parts of lauric acid (Nanjing Dongde Chemical Technology Co., Ltd.), 47 parts of fumed silica (HP-200 Hongbai, 200±25m2 / g Jiangxi Hongbai New Materials Co., Ltd.) were added in batches of 14 parts, 11 parts, 10 parts, 7 parts, 3 parts, and 2 parts. The components were kneaded at 100℃, the rubber was discharged, and the rubber was divided into blocks. It was stored for 7 hours, and then put into the kneading machine and heated to about 160℃ for high-temperature mixing for 3 hours, kept warm, and low-molecular substances were removed. The rubber was cooled to 40℃. Add 1.5 parts of Wacker heat-resistant agent H3 and 1.5 parts of carbon black masterbatch (FR5300, Shanghai Furui Chemical Co., Ltd., mixed with methyl vinyl silicone rubber with a vinyl content of 0.08% and a molecular weight of 700000 g / mol in a ratio of 2:3, and grinded 15 times by a three-roll grinder) and continue kneading (cooling water is required, the temperature is 40°C) for 20 minutes before discharging, the rubber is divided into sheet rubber, cooled for more than 30 minutes, and then open-mixed, filtered, weighed, and packaged to obtain a mixed rubber. Take 100 parts of the mixed rubber, mix and disperse 1.0 parts of 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane (C-6A) with a 150mm open mill, and after thinning, a curable silicone rubber composition is prepared. The curable silicone rubber composition is subjected to plate vulcanization at 170°C for 10 minutes, i.e., primary vulcanization, and post-vulcanization at 200°C for 2 hours, i.e., secondary vulcanization, and its mechanical properties are tested.

[0082] Example 8

[0083] 100 parts of methyl vinyl silicone rubber with an average molecular weight of 500,000 and an average vinyl content of 0.40 mol% (including 94.7 parts of methyl vinyl silicone rubber with a molecular weight of 496,000 and a vinyl content of 0.37 mol%, 3.5 parts of methyl vinyl silicone rubber with a molecular weight of 640,000 and a vinyl content of 0.13 mol%, and 1.8 parts of methyl vinyl silicone rubber with a molecular weight of 450,000 and a vinyl content of 2.7 mol%); 40 parts of white carbon black; 3 parts of a structural control agent (0.2 parts of diphenyl dihydroxy silicone oil, 1.3 parts of hydroxy silicone oil) , 0.1 part of vinyl trimethoxysilane, 0.2 part of vinyl triethoxysilane, 1.2 parts of hexamethyldisilazane), 0.3 part of hydrogenated silicone oil (hydrogen content (wt%) at 0.36%, viscosity 50 mm2 / s), 0.3 part of deionized water, 0.01 part of internal release agent (0.006 part of barium stearate, 0.004 part of magnesium stearate), 5 parts of black masterbatch, 0.5 part of heat-resistant agent (0.1 part of titanium dioxide, 0.2 part of cerium oxide, 0.1 part of iron oxide, 0.1 part of zirconium oxide), 0.5 part of vulcanizing agent (diisopropylbenzene peroxide); the banburying temperature is 120°C and the time is 5 hours. Others are the same as in Example 5.

[0084] Example 9

[0085] 100 parts of methyl vinyl silicone rubber with an average molecular weight of 750,000 and an average vinyl content of 0.05 mol% (including 48 parts of methyl vinyl silicone rubber with a molecular weight of 740,000 and a vinyl content of 0.04 mol%, 51.7 parts of methyl vinyl silicone rubber with a molecular weight of 760,000 and a vinyl content of 0.06 mol%, and 0.3 parts of methyl vinyl silicone rubber with a molecular weight of 680,000 and a vinyl content of 1.0 mol%); 60 parts of white carbon black; 12 parts of structural control agent (2.0 parts of dimethyldiethoxysilane, 6 parts of methylphenyldimethoxysilane, 2.0 parts of vinylsilazane, 2.0 parts of hexamethyldisilazane), 2 parts of hydrogenated silicone oil (hydrogen content (wt%) at 1.6%, viscosity 100mm2 / s), 0.5 parts of deionized water, 0.5 parts of internal release agent (0.2 parts of zinc laurate, 0.3 parts of magnesium laurate), 0.5 parts of black masterbatch, 5 parts of heat-resistant agent (1 part of cerium oxide, 1 part of yttrium oxide, 3 parts of carbon black), vulcanizing agent (sub-average platinum A 0.6%, B 1.4%); the banburying temperature is 150°C and the time is 2h. Others are the same as in Example 5.

[0086] Comparative Example 1

[0087] The difference from Example 5 is that 1.5 parts of Wacker heat-resistant agent H3 is added, and no carbon black masterbatch (ie, black masterbatch) is added. The rest is the same as Example 5.

[0088] Comparative Example 2

[0089] The difference from Example 5 is that Wacker heat-resistant agent H3 is not added. Others are the same as Example 5.

[0090] Comparative Example 3

[0091] The difference from Example 5 is that no carbon black masterbatch is added, and 1.5 parts of iron black masterbatch (KN-320, Huzhou Hutian Yaocai Pigment Co., Ltd., the mixing ratio is the same as carbon black) is added. The rest is the same as Example 5.

[0092] Comparative Example 4

[0093] The difference from Example 5 is that 1.5 parts of Wacker heat-resistant agent H3 and 1.5 parts of carbon black masterbatch (Japan Mitsubishi MA100, mixed with methyl vinyl silicone rubber with a vinyl content of 0.08% and a molecular weight of 700000 g / mol in a ratio of 2:3, and not ground by a three-roll mill) are added. The rest is the same as Example 5.

[0094] Comparative Example 5

[0095] The difference from Implementation 5 is that no hydrogen-containing silicone oil (viscosity (25°C), mm2 / s: 80, hydrogen content: (wt%) 0.6) is added, and the rest remains the same as Example 5.

[0096] Comparative Example 6

[0097] The difference from Implementation 5 is that 0.4 parts of 2,5-dimethyl-2,5-di-tert-butyl peroxyhexane (C-6A) is added, and the rest is the same as Implementation 5.

[0098] The silicone rubber data measured in the following table are respectively tested according to national standards for the Shore hardness, tensile strength, elongation at break, compression set performance, hot air aging performance, and oil resistance of the silicone rubber prepared in the embodiments and comparative examples of the present invention. The specific test methods are as follows: Shore hardness is tested according to GB / T531.1-2008 standard; tensile strength and elongation are tested according to GB / T 528-2009 standard; compression set performance is tested according to GB / T 7759.1-2015 standard; breakdown voltage strength is tested according to GB / T1695-2005 standard; hot air aging is tested according to GB / T 3512-2004 standard; oil resistance is tested according to GB / T 1690-2010 standard. The experimental data obtained from the test refer to the secondary vulcanization, compression set performance, breakdown voltage strength, hot air aging performance, and oil resistance of silicone rubber in Tables 1-2 below.

[0099] Table 1 is the test results of the embodiment

[0100]

[0101]

[0102]

[0103] Table 2 Test results of comparative examples

[0104]

[0105]

[0106] Comparative Example 1 Compared with Example 5, the oil resistance is significantly reduced without adding the black masterbatch. Example 5 has excellent performance This is because the black masterbatch has excellent thermal stability and chemical stability, can absorb and disperse the internal stress generated by the silicone rubber when heated, and improve the heat resistance of the silicone rubber; the carbon black particles in the carbon black masterbatch have a strong interaction force with the silicone rubber molecular chain, can form a tight cross-linking network, can prevent the penetration and diffusion of oil media, and can also enhance the compactness of the silicone rubber, thereby improving the oil resistance of the silicone rubber.

[0107] Compared with Example 5, Comparative Example 2 does not add Wacker heat-resistant agent H3, and the heat resistance is significantly reduced, and the oil resistance is also reduced. This is because as the temperature increases, silicone rubber will undergo thermal degradation; and the swelling rate of silicone rubber in the solvent increases with the increase in temperature. According to Comparative Examples 1, 2 and Example 5, the use of heat-resistant agent and masterbatch can significantly improve the heat and oil resistance of silicone rubber. If Wacker heat-resistant agent H3 is not added and only black masterbatch is added, this balance will be broken, which is not conducive to the performance of silicone rubber. According to Comparative Examples 1, 2 and Example 5, heat-resistant carbon black and pigment carbon black work synergistically to improve the heat and oil resistance of silicone rubber.

[0108] In Comparative Example 3, relative to Example 5, carbon black is replaced by iron black. Although iron black itself has a certain degree of blackness, its tinting strength, temperature resistance and oil resistance are not as good as those of carbon black, and iron black will turn into reddish brown when baked at high temperature. In some downstream products with strict requirements on color, the color change may cause the product to be judged as unqualified. Therefore, the use of iron black in products is limited to a certain extent.

[0109] Comparative Example 4 Compared with Example 5, the black masterbatch was replaced with Japanese Mitsubishi MA100 and was not ground by a three-roll mill. The performance change rate after aging at 275℃*70h was greater, and the performance change rate in standard oil was also greater. This is because the specific surface area of ​​Japanese Mitsubishi MA100 is lower and the dispersibility of the unground masterbatch is worse. The masterbatch in the example has a large specific surface area, and the smaller the particle size of the ground carbon black is, the greater the light absorption performance is, the higher the blackness is, and the more obvious the performance improvement is.

[0110] Compared with Example 5, in Comparative Example 5, no hydrogen-containing silicone oil is added, and the basic mechanical properties of the silicone rubber are reduced and the rate of change after aging and oil resistance is also greater. This is because the absence of hydrogen-containing silicone oil will lead to a decrease in the degree of cross-linking, making the silicone rubber structure unstable, thereby affecting the hardness and heat and oil resistance of the silicone rubber.

[0111] Comparative Example 6 uses a lower content of 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane relative to Example 5, and the effective content of the vulcanizer used is low, and the basic mechanical properties of the rubber, the performance after aging, and the oil resistance are slightly lower. This is because the effective content of the vulcanizer directly affects the crosslinking density of the silicone rubber. A low effective content means that the crosslinking reaction is insufficient, resulting in a reduction in the number of crosslinking points and a sparse crosslinking network, which will weaken the interaction between the silicone rubber molecular chains, making it more likely to deform and break when subjected to external forces, thereby reducing its tensile strength and other mechanical properties. Similarly, the imperfection of the crosslinking network makes silicone rubber more susceptible to thermal degradation in a high temperature environment and oil substances more likely to penetrate into the interior of the silicone rubber and destroy its crosslinking structure, thereby reducing the mechanical properties.

[0112] Figure 1 This is a comparison chart of the rubber compound with carbon black added in Example 5 after secondary vulcanization and aging at 275℃*70h. The rubber compound on the left is secondary vulcanized, and the rubber compound on the right is baked after aging at 275℃*70h. Figure 2 This is a comparison chart of the rubber compound with iron black added in comparative example 3 after secondary vulcanization and aging at 275℃*70h. The rubber compound on the left is secondary vulcanized, and the rubber compound on the right is baked after aging at 275℃*70h. Figure 1 It can be seen that the appearance of the rubber compound with carbon black added has no obvious change after high temperature baking and remains black. Figure 2 It can be seen that the rubber compound with iron black added turns reddish brown after high-temperature baking, and the color change is obvious. This color change will affect the use of downstream products.

[0113] Although the embodiments disclosed in the present invention are as above, the contents described are only embodiments adopted to facilitate understanding of the present invention and are not intended to limit the present invention. Any technician in the field to which the present invention belongs can make any modifications and changes in the form and details of implementation without departing from the spirit and scope disclosed in the present invention, but the patent protection scope of the present invention shall still be subject to the scope defined in the attached claims.

Claims

1. A silicone rubber, characterized in that: The invention is composed of the following components in parts by weight: 100 parts of methyl vinyl silicone rubber raw rubber, 40-60 parts of white carbon black, 3-12 parts of structuring control agent, 0.3-2.0 parts of hydrogenated silicone oil, 0.1-4.0 parts of polyvinyl silicone oil, 0.3-0.5 parts of deionized water, 0.01-0.5 parts of internal mold release agent, 0.5-5 parts of black masterbatch, 0.5-10 parts of heat resistant agent and 0.5-2 parts of vulcanizing agent.

2. The silicone rubber according to claim 1, characterized in that The molar mass of the methyl vinyl silicone rubber raw rubber is between 500000-750000 g / mol, and the content of vinyl in the methyl vinyl silicone rubber raw rubber is 0.05-0.4% in molar percentage.

3. The silicone rubber according to claim 1, characterized in that The white carbon black is fumed white carbon black; preferably, the white carbon black has a specific surface area of ​​150-350m 2 / g of silica.

4. The silicone rubber according to claim 1, characterized in that: The structuring control agent includes one or more of hydroxy silicone oil, vinyl hydroxy silicone oil, diphenyl dihydroxy silicone oil, dimethyl dimethoxy silane, dimethyl diethoxy silane, methyl phenyl dimethoxy silane, hexamethyl disilazane, vinyl silazane, vinyl trimethoxy silane, vinyl triethoxy silane and active silicone oil.

5. The silicone rubber according to claim 1, characterized in that: The hydrogen content of the hydrogen-containing silicone oil is between 0.36% and 1.6% by mass, and the viscosity is 50-100 mm 2 / s.

6. The silicone rubber according to claim 1, characterized in that: The polyvinyl silicone oil is a methyl-terminated methyl vinyl silicone oil with a viscosity of 2500-10000mm 2 / s, vinyl content 8.0-15.0%.

7. The silicone rubber according to claim 1, characterized in that: The internal mold release agent is one or more of zinc stearate, calcium stearate, barium stearate, magnesium stearate, zinc laurate, magnesium laurate, palmitic acid, polyethylene glycol distearate, lauric acid, and stearic acid; and / or the heat-resistant agent is one or two of cerium oxide, iron oxide, zirconium oxide, titanium dioxide, yttrium oxide, carbon black, etc.; And / or the vulcanizing agent is one or more of 2,5-dimethyl-2,5-di-tert-butyl peroxide hexane (C-6A, C-6B, C-8A, C-8B, etc.), diisopropylbenzene peroxide, benzoyl peroxide, 2,4-dichlorobenzoyl peroxide or platinum vulcanizing agent.

8. The silicone rubber according to claim 1, characterized in that: The black masterbatch is a mixture of carbon black pigment in the blue phase and methyl vinyl silicone rubber raw rubber, wherein the effective content of the carbon black pigment is 30-50% by mass; Preferably, the blue phase carbon black pigment in the black masterbatch is in the form of fluffy powder with a volume density of 120-380 kg / m3; Preferably, the methyl vinyl silicone rubber raw rubber in the black masterbatch is a methyl vinyl silicone rubber raw rubber with a vinyl content of 0.05-0.25% and a molecular weight of 650000-750000 g / mol. Preferably, the mixing ratio of the pigment carbon black and the methyl vinyl silicone rubber raw rubber in the black masterbatch is 3:7-5:5, and the black masterbatch is ground by a three-roll grinder for 10-15 times.

9. A method for preparing silicone rubber, characterized in that: include: Mixing methyl vinyl silicone rubber, part of the structure control agent and deionized water in a kneader to obtain a first mixed material; Add the remaining structure control agent, hydrogen-containing silicone oil, polyvinyl silicone oil, internal mold release agent, and white carbon black to the first mixed material, mix well, and obtain a second mixed material; The second mixed material is kneaded to obtain a mixed base rubber, and the mixed base rubber is mixed with a heat-resistant agent and a black masterbatch, and the silicone rubber is obtained after mixing.

10. The method for preparing silicone rubber according to claim 9, characterized in that: The preparation conditions of the first mixture are 10-30 min; and / or the second mixed material is prepared by mixing at a temperature of 100° C. and standing for 4-8 hours; And / or the banburying conditions are 0.04-0.08MPa, temperature 120-170°C, 2-5h; And / or the mixing condition of the base rubber, the heat-resistant agent and the black masterbatch is room temperature to 100°C.

Images