A high-compression-resilience silicone sealant and its preparation method

Abstract

This invention relates to a high-compression-resilience silicone sealant and its preparation method, belonging to the field of silicone modification technology. The high-compression-resilience silicone sealant, by weight, comprises 20-35 parts methyl vinyl MQ resin, 30-50 parts vinyl silicone oil 1, 30-50 parts vinyl silicone oil 2, 1-3 parts silane coupling agent, 3-9 parts hydrogen-containing silicone oil, 5-20 parts silica, 0.02-0.1 parts Pt catalyst, 0.02-0.1 parts inhibitor, and 0.03-0.5 parts black pigment. The addition of vinyl silicone oil 1 improves the sealant's resilience; the addition of vinyl silicone oil 2 improves the sealant's toughness.

Description

Technical Field

[0001] This invention relates to a high-compression-resilience silicone sealant and its preparation method, belonging to the field of silicone modification technology. Background Technology

[0002] CIPG (In-line Molded Gas Seal Technology) plays a crucial role in the manufacturing of new energy vehicles. By providing superior sealing performance, it ensures the sealing performance of battery systems, motors and electronic control systems, cooling systems, and other critical components, providing vital support for the safety, reliability, and performance of new energy vehicles. With the continuous development of the new energy vehicle market, CIPG technology will continue to play a key role, driving innovation and progress in new energy vehicle manufacturing. A key factor in ensuring the sealant's superior performance lies in its excellent compression recovery properties. With a compression of 30%, after testing in various high-temperature environments, the sealant should show no significant deformation or corrosion, and after pressure release, it should quickly rebound to at least 95% of its original compression value. Ordinary silicone sealant often fails to meet these requirements. Summary of the Invention

[0003] The purpose of this invention is to address the shortcomings of existing technologies by disclosing a high-compression-resilience silicone sealant and its preparation method. The vinyl silicone oil 1 used in this sealant improves its resilience; the addition of vinyl silicone oil 2 improves its toughness.

[0004] One objective of this invention is to provide a high-compression-resilience silicone sealant, which, by weight, comprises 20-35 parts methyl vinyl MQ resin, 30-50 parts vinyl silicone oil 1, 30-50 parts vinyl silicone oil 2, 1-3 parts silane coupling agent, 3-9 parts hydrogen-containing silicone oil, 5-20 parts silica, 0.02-0.1 parts Pt catalyst, 0.02-0.1 parts inhibitor, and 0.03-0.5 parts black pigment.

[0005] The structure of the vinyl silicone oil 1 is as follows:

[0006]

[0007] Where m, n, and o are integers greater than or equal to 1;

[0008] The structure of the vinyl silicone oil 2 is as follows:

[0009]

[0010] The value of x is an integer greater than or equal to 1.

[0011] The methyl vinyl MQ resin has a vinyl content of 0.35–0.6 mmol / g and a viscosity of 4000–10000 mPa·s at 25°C.

[0012] The silane coupling agent is at least one of methacryloyloxypropyltrimethoxysilane, methacryloyloxypropyltriethoxysilane, and allyltrimethoxysilane.

[0013] The hydrogen-containing silicone oil has a hydrogen content of 0.25–10 mmol / g and a viscosity of 25–80 mPa·s at 25°C; the silica is a hydrophobic silica with a specific surface area of ​​140–250 m² / g.

[0014] The Pt catalyst is a vinylsiloxane complex of chloroplatinic acid with a platinum content of 2500-6500 ppm; the inhibitor is at least one of 3-methyl-1-butyn-3-ol, trimethyl-1-pentyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, and 1-ethynyl-1-cyclohexanol.

[0015] The black color paste is a general-purpose color paste made by mixing silicone oil and nano carbon black purchased from the market.

[0016] The second objective of this invention is to provide a method for preparing the high-compression-resilience silicone sealant, comprising the following steps: mixing 20-35 parts by weight of methyl vinyl MQ resin, 30-50 parts by weight of vinyl silicone oil 1, 30-50 parts by weight of vinyl silicone oil 2, 1-3 parts by weight of silane coupling agent, 3-9 parts by weight of hydrogen-containing silicone oil, 5-20 parts by weight of silica, 0.02-0.1 parts by weight of Pt catalyst, 0.02-0.1 parts by weight of inhibitor, and 0.03-0.5 parts by weight of black pigment paste.

[0017] The preparation method of the vinyl silicone oil 1 includes the following steps: adding tetramethyldivinyldisiloxane, hexaphenylcyclotrisiloxane, octamethylcyclotetrasiloxane, and tetramethyltetravinylcyclotetrasiloxane to a reaction vessel, stirring at room temperature for 15-30 min, then adding tetramethylammonium hydroxide, slowly raising the temperature to 95-115℃, stirring for 2-8 h, then raising the temperature to 150-160℃, and stirring under vacuum conditions of less than 0.085 MPa for 2-8 h to obtain vinyl silicone oil 1. The molar ratio of tetramethyldivinyldisiloxane, hexaphenylcyclotrisiloxane, octamethylcyclotetrasiloxane, and tetramethyltetravinylcyclotetrasiloxane is 1-3:1-3:2-6:5-20.

[0018] The reaction formula is:

[0019]

[0020] The values ​​of m, n, and o are integers greater than or equal to 1.

[0021] The preparation method of the vinyl silicone oil 2 includes the following steps: Methyltrimethoxysilane, dimethyldimethoxysilane, and hexavinyldisiloxane are added to a reaction vessel equipped with a water separator in a molar ratio of 1-1.5:10-30:1.5-5. Under stirring at room temperature, a sulfuric acid aqueous solution of 0.5-5% of the total mass of the above silanes is slowly added dropwise. The sulfuric acid concentration in the aqueous solution is 1%-7%. The reaction is then carried out at 55-75°C for 0.5-1.5 hours. The oil temperature is then set to 85-90°C to separate the generated small molecule alcohols for 2-3 hours. Then, toluene is added at 1-2 times the weight of the system, and the reaction is carried out at 95-100°C to remove water for 3-5 hours. Finally, toluene is removed under a vacuum of less than 0.085 MPa at 95-110°C to obtain vinyl silicone oil 2. The reaction formula is:

[0022]

[0023] The value of x is an integer greater than or equal to 1.

[0024] Compared with the prior art, the beneficial effects of the present invention are as follows: the use of vinyl silicone oil 1 in the sealant prepared by the present invention improves the resilience of the sealant; the addition of vinyl silicone oil 2 improves the toughness of the sealant while maintaining a certain elasticity. Detailed Implementation

[0025] The present invention will be described below with reference to examples. These examples are only used to explain the present invention and are not intended to limit the scope of the present invention.

[0026] 18.6 g of tetramethyldivinyldisiloxane, 59.5 g of hexaphenylcyclotrisiloxane, 59.3 g of octamethylcyclotetrasiloxane, and 344 g of tetramethyltetravinylcyclotetrasiloxane were added to a three-necked flask. The mixture was stirred at room temperature for 20 min, then 0.1 g of tetramethylammonium hydroxide was added. The temperature was slowly raised to 100 °C and stirred for 4 h. The temperature was then increased to 160 °C and stirred for 4 h under a vacuum condition of less than 0.085 MPa. Finally, vinyl silicone oil 1 was obtained.

[0027] 13.6 g of methyltrimethoxysilane, 240 g of dimethyldimethoxysilane, and 35.1 g of hexavinyldisiloxane were added to a four-necked flask equipped with a water separator. 2 g of a 1% sulfuric acid aqueous solution was slowly added dropwise while stirring at room temperature. The mixture was then reacted at 60°C for 1 hour. The oil temperature was set to 85°C to separate the generated small molecule alcohol for 2 hours. Then, toluene (1 times the total weight of all the aforementioned substances) was added, and the mixture was reacted at 100°C to remove water for 4 hours. Finally, the toluene solvent was removed by maintaining a high temperature of 110°C under a vacuum of less than 0.085 MPa, yielding vinyl silicone oil 2.

[0028] Example 1

[0029] Methyl vinyl MQ resin (vinyl content 0.6 mmol / g, viscosity at 25℃ 6000 mPa·s), vinyl silicone oil 1, vinyl silicone oil 2, methacryloxypropyltrimethoxysilane, hydrogen-containing silicone oil (hydrogen content 5.5 mmol / g, viscosity at 25℃ 30 mPa·s), and silica (specific surface area 180 m² / g). 2 The following ingredients are mixed in a weight ratio of 25:30:30:2:3.5:12:0.1:0.06:0.5: hydrophobic silica, Pt catalyst (vinylsiloxane complex of chloroplatinic acid, platinum content 2500ppm), 3-methyl-1-butyn-3-ol, and black pigment paste.

[0030] Example 2

[0031] Methyl vinyl MQ resin (vinyl content 0.6 mmol / g, viscosity at 25℃ 6000 mPa·s), vinyl silicone oil 1, vinyl silicone oil 2, methacryloxypropyltrimethoxysilane, hydrogen-containing silicone oil (hydrogen content 5.5 mmol / g, viscosity at 25℃ 30 mPa·s), and silica (specific surface area 180 m² / g). 2 The following ingredients are mixed in a weight ratio of 25:40:20:2:3.5:12:0.1:0.06:0.5: hydrophobic silica, Pt catalyst (vinylsiloxane complex of chloroplatinic acid, platinum content 2500ppm), 3-methyl-1-butyn-3-ol, and black pigment paste.

[0032] Example 3

[0033] Methyl vinyl MQ resin (vinyl content 0.6 mmol / g, viscosity at 25℃ 6000 mPa·s), vinyl silicone oil 1, vinyl silicone oil 2, methacryloxypropyltrimethoxysilane, hydrogen-containing silicone oil (hydrogen content 5.5 mmol / g, viscosity at 25℃ 30 mPa·s), and silica (specific surface area 180 m² / g). 2 The following ingredients are mixed in a weight ratio of 25:20:40:2:3.5:12:0.1:0.06:0.5: hydrophobic silica, Pt catalyst (vinylsiloxane complex of chloroplatinic acid, platinum content 2500ppm), 3-methyl-1-butyn-3-ol, and black pigment paste.

[0034] Comparative Example 1

[0035] Methyl vinyl MQ resin (vinyl content 0.6 mmol / g, viscosity at 25℃ 6000 mPa·s), vinyl silicone oil 1, methacryloxypropyltrimethoxysilane, hydrogen-containing silicone oil (hydrogen content 5.5 mmol / g, viscosity at 25℃ 30 mPa·s), and silica (specific surface area 180 m² / g). 2 The following ingredients are mixed in a weight ratio of 25:60:2:3.5:12:0.1:0.06:0.5: hydrophobic silica, Pt catalyst (vinylsiloxane complex of chloroplatinic acid, platinum content 2500ppm), 3-methyl-1-butyn-3-ol, and black pigment paste.

[0036] Comparative Example 2

[0037] Methyl vinyl MQ resin (vinyl content 0.6 mmol / g, viscosity at 25℃ 6000 mPa·s), vinyl silicone oil 2, methacryloxypropyltrimethoxysilane, hydrogen-containing silicone oil (hydrogen content 5.5 mmol / g, viscosity at 25℃ 30 mPa·s), and silica (specific surface area 180 m² / g). 2 The following ingredients are mixed in a weight ratio of 25:60:2:3.5:12:0.1:0.06:0.5: hydrophobic silica, Pt catalyst (vinylsiloxane complex of chloroplatinic acid, platinum content 2500ppm), 3-methyl-1-butyn-3-ol, and black pigment paste.

[0038] Comparative Example 3

[0039] Methyl vinyl MQ resin (vinyl content 0.6 mmol / g, viscosity at 25℃ 6000 mPa·s), double-ended vinyl silicone oil (vinyl content 0.06 mmol / g, viscosity at 25℃ 5000 mPa·s), methacryloxypropyltrimethoxysilane, hydrogen-containing silicone oil (hydrogen content 5.5 mmol / g, viscosity at 25℃ 30 mPa·s), and silica (specific surface area 180 m² / g). 2 The following ingredients were mixed in a weight ratio of 25:30:2:3.5:12:0.1:0.06:0.5: hydrophobic silica, Pt catalyst (vinylsiloxane complex of chloroplatinic acid, platinum content 2500ppm), 3-methyl-1-butyn-3-ol, and black pigment paste.

[0040] The performance of the samples is shown in Table 1, and the test methods are described in Table 1.

[0041] Table 1. Performance Test Results

[0042]

[0043]

[0044] Compared to Examples 2 and 3, in Example 1, the effect of adding vinyl silicone oil 1 on compression rebound gradually decreases after reaching a certain value, while the effect on tear strength increases significantly with the reduction of vinyl silicone oil 2. Compared to Comparative Examples 1, 2, and 3, Example 1 shows that vinyl silicone oil 1 can reduce the compression loss rate of the sealant. This is due to the presence of appropriate side vinyl groups in the silicone oil. Simultaneously, the appropriate amount of phenyl groups in vinyl silicone oil 1 increases steric hindrance, making cross-linking structure deformation more difficult, thus its effect of reducing the compression loss rate of the sealant is more significant. The appropriate amount of T-structures in vinyl silicone oil 2 increases the tear resistance of the colloid.

[0045] The above description is only a preferred embodiment of the present invention and is not intended to limit the scope of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the concept and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high compression rebound silicone sealant, characterized by, According to parts by weight, comprising 20-35 parts of methyl vinyl MQ resin, 30-50 parts of vinyl silicone oil 1, 30-50 parts of vinyl silicone oil 2, 1-3 parts of silane coupling agent, 3-9 parts of hydrogen-containing silicone oil, 5-20 parts of white carbon black, 0.02-0.1 parts of Pt catalyst, 0.02-0.1 parts of inhibitor, 0.03-0.5 parts of black color paste; The structure of the vinyl silicone oil 1 is: Wherein, the value range of m, n, o is an integer greater than or equal to 1; The structure of the vinyl silicone oil 2 is: Wherein, the value range of x is an integer greater than or equal to 1.

2. The high compression rebound silicone sealant of claim 1, wherein, The vinyl content of the methyl vinyl MQ resin is 0.35-0.6 mmol / g, and the viscosity at 25°C is 4000-10000 mPa.S.

3. The high compression rebound silicone sealant of claim 1, wherein, The silane coupling agent is at least one of methacryloyloxypropyl trimethoxysilane, methacryloyloxypropyl triethoxysilane, and allyl trimethoxysilane.

4. The high compression rebound silicone sealant of claim 1, wherein, The hydrogen-containing silicone oil has a hydrogen content of 0.25-10 mmol / g and a viscosity of 25-80 mPa.S at 25℃; the white carbon black is a hydrophobic white carbon black with a specific surface area of 140-250 m 2 / g.

5. The high compression rebound silicone sealant of claim 1, wherein, The Pt catalyst is a vinyl siloxane complex of chloroplatinic acid, and the platinum content is 2500-6500 ppm; the inhibitor is at least one of 3-methyl-1-butyne-3-ol, trimethyl-1-pentyn-3-ol, 3,5-dimethyl-1-hexyne-3-ol, and 1-ethynyl-1 cyclohexanol.

6. A process for the preparation of a high compression-rebound silicone sealant according to any one of claims 1 to 5, characterized in that, The method comprises the following steps: according to parts by weight, 20-35 parts of methyl vinyl MQ resin, 30-50 parts of vinyl silicone oil 1, 30-50 parts of vinyl silicone oil 2, 1-3 parts of silane coupling agent, 3-9 parts of hydrogen-containing silicone oil, 5-20 parts of white carbon black, 0.02-0.1 parts of Pt catalyst, 0.02-0.1 parts of inhibitor, and 0.03-0.5 parts of black color paste are mixed to obtain.

7. The method for preparing the high-compression-resilience silicone sealant according to claim 6, characterized in that, The preparation method of the vinyl silicone oil 1 comprises the following steps: adding tetramethyl divinyl disiloxane, hexaphenyl cyclotrisiloxane, octamethyl cyclotetrasiloxane, and tetramethyl tetraethenyl cyclotetrasiloxane in a reaction container, stirring at room temperature for 15-30 min, then adding tetramethyl ammonium hydroxide, slowly warming the temperature to 95-115°C, stirring for 2-8 h, then increasing the temperature to 150-160°C, and stirring for 2-8 h under a vacuum degree of less than 0.085 Mpa to obtain the vinyl silicone oil 1.

8. The method of claim 7, wherein the high compression rebound silicone sealant is prepared by the steps of: The molar ratio of the tetramethyl divinyl disiloxane, hexaphenyl cyclotrisiloxane, octamethyl cyclotetrasiloxane, and tetramethyl tetraethenyl cyclotetrasiloxane is 1-3:1-3:2-6:5-20.

9. The method for preparing the high-compression-resilience silicone sealant according to claim 6, characterized in that, The preparation method of the vinyl silicone oil 2 comprises the following steps: adding methyltrimethoxysilane, dimethyldimethoxysilane and hexa-vinyl disiloxane into a reaction container with a water separator at a molar ratio of 1-1.5:10-30:1.5-5, slowly dropping 0.5-5% of the total mass of the above silane into an aqueous sulfuric acid solution with a mass concentration of 1%-7% under stirring at room temperature, then reacting at 55-75 ℃ for 0.5-1.5 hours, setting the oil temperature to 85-90 ℃ to separate the small molecule alcohol produced for 2-3 hours, then adding 1-2 times the weight of toluene into the system, reacting to remove water at 95-100 ℃ for 3-5 hours, and finally keeping 95-110 ℃ to remove toluene under a vacuum condition with a vacuum degree less than 0.085 Mpa to obtain the vinyl silicone oil 2.

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