High-resilience single-component organopolysiloxane composition and preparation method thereof

Abstract

The invention aims to provide the high-resilience single-component organopolysiloxane composition and the preparation method thereof, and the high-resilience single-component organopolysiloxane composition is suitable for sealing and bonding of various automobile, industrial and electronic components, and is particularly suitable for sealing and bonding scenes of CIPG (in-situ molded sealing washers). The high-resilience single-component organopolysiloxane composition at least comprises the following components (A)-(E): (A) organopolysiloxane with at least two alkenyl groups per molecule; (B) an organopolysiloxane having at least two Si-H bonds per molecule; (C) a hyperbranched organic silicon cross-linking agent; (D) a hydrosilylation catalyst; and (E) fumed silica. The hyperbranched organic silicon cross-linking agent is prepared by taking multifunctional organic silicon molecules as a core basis of a hyperbranched structure through hydrosilylation reaction. On one hand, through the hyperbranched structure, the spatial distance between cross-linking points is increased, so that the cured polysiloxane composition has good resilience; and on the other hand, active groups for increasing interface adhesion are introduced into the hyperbranched organic silicon cross-linking agent, so that the hyperbranched organic silicon cross-linking agent has a cross-linking and curing effect and also has good adhesion performance on a material interface.

Description

Technical Field

[0001] The invention relates to a high-resilience single-component organopolysiloxane composition and a preparation method thereof, and belongs to the field of thermal curing, adhesive sealing, and in-situ formed sealing gasket (CIPG) solution. Background Art

[0002] Silicone materials have gained widespread attention and application in all walks of life due to their excellent heat resistance, cold resistance, dielectric properties, ozone resistance and atmospheric aging resistance, and a wide operating temperature range. They can be used for a long time at -60°C (or lower temperatures) to +250°C (or higher temperatures).

[0003] In the face of the current new energy vehicle industry's requirements for precision, airtightness and integration, the design of new automotive sealed connectors on automotive motors, electronic controls, oil pump controllers and EHPS steering pumps has shown a trend of large size and complex structure. A sealing technology for automotive connectors based on CIPG technology is proposed. At the same time, the sealing product has the performance requirements of high temperature resistance, low temperature resistance, high pressure resistance and high humidity resistance, especially the mainstream direction of future development and application of automotive sealed connectors.

[0004] The present invention aims to introduce a single-component organopolysiloxane composition with high resilience after curing and a preparation method thereof, which is suitable for sealing and bonding of various automotive, industrial and electronic components, especially for sealing and bonding scenarios of formed-in-situ sealing gaskets (CIPG). On the one hand, by designing the molecular structure of the hyperbranched organosilicon crosslinker, the spatial distance between the crosslinking points can be increased, so that the cured polysiloxane composition has good resilience; on the other hand, active groups that increase interfacial bonding are introduced into the hyperbranched organosilicon crosslinker, which not only plays a crosslinking and curing role, but also has good bonding properties to the material interface. Summary of the invention

[0005] The purpose of the present invention is to provide a single-component organopolysiloxane composition with high resilience after curing and a preparation method thereof, which is suitable for sealing and bonding of various automotive, industrial and electronic components, especially for sealing and bonding scenarios of in-situ formed sealing gaskets (CIPG). The present invention uses multifunctional organosilicon molecules as the core basis of the hyperbranched structure, and prepares a hyperbranched organosilicon crosslinker through a hydrosilylation reaction. The crosslinker has a multifunctional active crosslinker that can participate in the hydrosilylation reaction, and also contains an active group that can increase interfacial bonding. On the one hand, by designing the molecular structure of the hyperbranched organosilicon crosslinker, the spatial distance between the crosslinking points can be increased, so that the cured polysiloxane composition has good resilience; on the other hand, an active group that increases interfacial bonding is introduced into the hyperbranched organosilicon crosslinker, which not only plays a crosslinking and curing role, but also has good bonding performance on the material interface.

[0006] The high resilience one-component organopolysiloxane composition of the present invention comprises at least the following components (A) to (E): (A) 5 to 80 parts of an organopolysiloxane having at least 2 alkenyl groups per molecule; (B) 0-10 parts of an organopolysiloxane having at least 2 Si-H bonds per molecule; (C) 0-60 parts of a hyperbranched organosilicon crosslinking agent; (D) 0-1 part of a hydrosilylation catalyst; (E) 10-40 parts of fumed silica; The component (A) is an organopolysiloxane having at least 2 alkenyl groups per molecule, and its general structural formula is (R 1 R 2 2SiO 1 / 2 )(R 1 R 2 SiO 2 / 2 ) a (R 2 SiO 3 / 2 ) b (SiO 4 / 2 ) c , where R 1 , R 2 Each of them independently represents an unsubstituted or substituted monovalent hydrocarbon group. As the monovalent hydrocarbon group, a group having 1 to 10 carbon atoms, particularly preferably 1 to 6 carbon atoms, specifically, lower alkyl groups such as methyl, ethyl, propyl, isopropyl, cycloalkyl groups such as cyclohexyl, aryl groups such as phenyl, tolyl, xylyl, aralkyl groups such as benzyl, alkane groups containing olefinic bonds such as vinyl and propenyl, or groups in which some or all of the hydrogen atoms of the above groups are replaced by halogen atoms, cyano groups, etc., such as chloromethyl and cyanoethyl. More preferably, it is preferably selected from groups such as methyl, ethyl, vinyl, phenyl, etc., and R 1 and R 2 At least one of the groups is vinyl; a = 0~500 (excluding 0), b = 0~2, c = 0~2, a+b+c = 1~500.

[0007] The component (B) is an organopolysiloxane having at least 2 Si-H bonds per molecule, and its general structural formula is (R 3 R 4 2SiO 1 / 2 )(R 3 R 4 SiO 2 / 2 ) m (R 5 SiO 3 / 2 ) n (SiO 4 / 2 ) x, where R 3 , R 4 , R 5 Each of them independently represents an unsubstituted or substituted monovalent hydrocarbon group. As the monovalent hydrocarbon group, a group having 1 to 10 carbon atoms, particularly preferably 1 to 6 carbon atoms, can be specifically listed as: a lower alkyl group such as methyl, ethyl, propyl, isopropyl, a cycloalkyl group such as cyclohexyl, an aryl group such as phenyl, tolyl, xylyl, an aralkyl group such as benzyl, an alkane group containing an olefinic bond such as vinyl, propenyl, or a group in which some or all of the hydrogen atoms of the above groups are replaced by halogen atoms, cyano, etc., such as chloromethyl, cyanoethyl, etc. More preferably, it is preferably selected from a group such as methyl, ethyl, phenyl, and R 3 , R 4 and R 5 At least one of the groups is a hydrogen atom; m=0~100, n=0~3, x=0~2, m+n+x=0.5~100.

[0008] The component (C) is a hyperbranched organosilicon crosslinking agent, and its chemical structure can be expressed as:

[0009] Among them, y = an integer between 0 and 5, and the maximum value of y should not exceed 5. If it exceeds 5, on the one hand, too many reaction steps are required, which is inefficient, and on the other hand, the chain segment is too long, which has no substantial significance for improving the rebound.

[0010] The core can be one of 1,3,5,7-tetramethylcyclotetrasiloxane, tetraepoxycyclohexylethyl 2,4,6,8-tetramethylcyclotetrasiloxane, 1,3,5,7,9-pentamethylcyclopentasiloxane, pentamethylpentavinylcyclopentasiloxane, tetramethyltetravinylcyclotetrasiloxane, octavinyl-POSS, side vinyl silicone oil, side hydrogen-containing silicone oil, terminal side vinyl silicone oil, and terminal side hydrogen-containing silicone oil, and the side vinyl silicone oil, side hydrogen-containing silicone oil, terminal side vinyl silicone oil, and terminal side hydrogen-containing silicone oil described in the present invention specifically refer to the number of vinyl or Si-H groups in each molecule ≥3.

[0011] The preparation method of the component (C) hyperbranched organosilicon crosslinking agent is: When the active functional group of the core is vinyl: ① dilute a certain amount of the raw material representing the core with toluene by 1-3 times, then add a certain proportion of platinum catalyst, mix well and set aside; ② add a certain amount of 1,1,3,3-tetramethyldisiloxane to the reaction bottle, dilute it with toluene by 1-3 times, stir well and heat to 40-60°C, then slowly drop the mixture obtained in the previous step, control the reaction temperature to <70°C, and after the dropwise addition is completed, keep the temperature for reaction for 2 hours; ③ add a certain amount of tetramethyldivinyldisiloxane to the reaction bottle, dilute it with toluene by 1-3 times, stir well and heat to 40-60°C, then add the mixture obtained in the previous step The mixture is slowly added dropwise, and the reaction temperature is controlled to be less than 70°C. After the addition is completed, the mixture is kept warm for 2 hours; steps ② and ③ are repeated until the target y value is obtained; when y=0 and 1, only ①→② is performed, and ③ is not required; when y=2 and 3, ①→②→③→② is required; when y=4 and 5, ①→②→③→②→③→② is required; after the repeated reaction of ④ is completed, a certain amount of the end-capping agent is heated to 40-60°C and diluted 1-3 times with toluene, and the mixture obtained in the first step is slowly added dropwise. After the addition is completed, the temperature is raised to 90-100°C, and the mixture is kept warm for 4 hours, and then the reaction is terminated; the solvent is removed by distillation under reduced pressure to obtain (C) a hyperbranched organosilicon crosslinking agent; When the active functional group of the core is Si-H, the platinum catalyst is mixed in step ③; after the reaction of step ①, step ③ is performed first, and then step ② is performed until the target y value is obtained; when y=1 and 2, ①→③→② is required; when y=3 and 4, ①→③→②→③→② is required; when y=5, ①→③→②→③→②→③ is required; after the repeated reaction of ④ is completed, a certain amount of the end-capping agent toluene diluted mixture heated to 40-60°C is slowly added dropwise to the mixture obtained in the first step, and after the addition is completed, the temperature is raised to 90-100°C, and the reaction is kept warm for 4 hours, and then the reaction is terminated; the solvent is removed by distillation under reduced pressure to obtain (C) a hyperbranched silicone crosslinking agent; When octavinyl-POSS is used as the core, the amount of toluene added is more than 10 times that of octavinyl-POSS; in the repeated reaction process of ② or ③, the amount of raw materials added is 1:1 in the ratio of vinyl to Si-H, and in the last step ④, the amount of the end-capping agent added is 1~1.2:1 in the ratio of vinyl to Si-H; The added amount of the platinum catalyst is 5-50ppm of the total weight of all raw materials participating in the reaction except toluene; the end-capping agent is one or more of tetramethyldivinyldisiloxane, 1,2-epoxy-4-vinylcyclohexane, allyl glycidyl ether, n-butyl acrylate, and 3-(methacryloyloxy)propyltrimethoxysilane.

[0012] The component (D) hydrosilylation catalyst can be selected from platinum-based catalysts, rhodium-based catalysts or palladium-based catalysts. Considering the catalytic activity, platinum-based catalysts are preferred. The platinum-based catalyst can be one or a mixture of platinum chloride, alcohol-modified platinum chloride, complexes of platinum chloride and dienes, platinum-olefin complexes, platinum-carbonyl complexes such as platinum bis(acetoacetate) or platinum bis(acetylacetone), platinum chloride-alkenylsiloxane complexes such as platinum chloride-divinyltetramethyldisiloxane complexes or platinum chloride-tetravinyltetramethylcyclotetrasiloxane, platinum-alkenylsiloxane complexes such as platinum-divinyltetramethyldisiloxane complexes or platinum-tetravinyltetramethylcyclotetrasiloxane complexes, complexes between platinum chloride and acetylene alcohol, and capsule-type platinum catalysts.

[0013] The component (E) fumed silica is preferably fumed silica treated with a treating agent, and the treating agent may be selected from one or a mixture of trimethylchlorosilane, dimethyldichlorosilane, dimethyldiethoxysilane, methyltrichlorosilane, trimethylethoxysilane, vinyltrimethoxysilane, γ-aminopropyltriethoxysilane, methyl silicone oil, ethyl silicone oil, tolyl silicone oil, methyl hydrogen silicone oil, ethyl hydrogen silicone oil, hydroxyl-containing silicone oil, hexamethyldisilazane, etc.

[0014] Based on this patent invention, adjustments can be made to meet the corresponding application requirements: such as adding fluorescent agents, carbon black, color paste, titanium dioxide, etc. to adjust the appearance and detection function; adding silicon powder, etc. for reinforcement; adding aluminum oxide, zinc oxide, magnesium oxide, aluminum hydroxide, etc. to improve the thermal conductivity and flame retardant function; adding inhibitors, etc. to adjust the storage period and working time, etc. The interaction between silicone oil or resin matrix and fumed silica can also be enhanced through the commonly used high-temperature treatment method to enhance the reinforcement effect; The present invention provides a single-component organopolysiloxane composition with high resilience after curing and a preparation method thereof, which is suitable for sealing and bonding of various automotive, industrial and electronic components, especially for sealing and bonding scenarios of in-situ formed sealing gaskets (CIPG). The beneficial effects of the present invention are as follows: ① Taking multifunctional organosilicon molecules as the core basis of hyperbranched structures, a hyperbranched organosilicon crosslinker is prepared by hydrosilylation reaction. By designing the molecular structure of the hyperbranched organosilicon crosslinker, the spatial distance between the crosslinking points can be increased, so that the cured polysiloxane composition has good resilience, which is convenient for the repair of automotive, industrial and electronic components; ② In traditional formulas, silane coupling agents are often used to improve the bonding performance of materials to the bonding interface. However, silane coupling agents often have no or only one reactive group for hydrosilylation, so while improving the bonding performance, it also has the side effect of reducing the strength of the body. The hyperbranched organosilicon crosslinking agent of the present invention has multiple functions as an active crosslinking agent that can participate in the hydrosilylation reaction, and also contains active groups that can increase the interfacial adhesion, thereby achieving the three-in-one effect of not reducing the bulk strength, enhancing the rebound and improving the adhesion performance. Implementation

[0016] The following specific embodiments describe the principles and features of the present invention. The examples are only used to explain the present invention and are not used to limit the scope of the present invention.

[0017] Example 1 Preparation of hyperbranched organosilicon crosslinking agent C-1: 500g of end-side vinyl silicone oil (vinyl content 0.5wt%, molecular weight 60,000) was diluted 3 times with toluene, and then 0.015g of platinum-divinyltetramethyldisiloxane complex (Pt 20wt%) was added, mixed evenly and set aside. 12.5g of 1,1,3,3-tetramethyldisiloxane was added to the reaction bottle, diluted 1 time with toluene, stirred evenly and heated to 40°C, and then the mixture obtained in the previous step was slowly added dropwise, and the reaction temperature was controlled to be less than 70°C. After the addition was completed, the reaction was kept warm for 2 hours.

[0018] 3.75g of vinyl trimethoxysilane was diluted 1 time with toluene, heated to 50°C, and slowly added dropwise to the mixture obtained in the first step. After the addition was completed, the temperature was raised to 90°C, and the reaction was kept at this temperature for 4 hours before the reaction was terminated. The solvent was removed by distillation under reduced pressure to obtain a hyperbranched organosilicon crosslinking agent C-1 with a hydrogen content of 0.13mmol / g.

[0019] Example 2 Preparation of Hyperbranched Organosilicon Crosslinking Agent C-2 500g of octavinyl-POSS was diluted 12 times with toluene, and then 0.1g of platinum-divinyltetramethyldisiloxane complex (Pt 20wt%) was added, mixed evenly and set aside. 848.7g of 1,1,3,3-tetramethyldisiloxane was added to the reaction bottle, diluted 2 times with toluene, stirred evenly and heated to 60°C, and then the mixture obtained in the previous step was slowly added dropwise, and the reaction temperature was controlled to be less than 70°C. After the addition was completed, the reaction was kept warm for 2 hours.

[0020] 117.1 g of vinyl trimethoxysilane, 90.17 g of allyl glycidyl ether, and 392.4 g of 3-(methacryloyloxy)propyl trimethoxysilane were mixed evenly, diluted 1 time with toluene, heated to 50°C, and slowly added dropwise the mixture obtained in the first step. After the addition was completed, the temperature was raised to 100°C, and the reaction was kept warm for 4 hours before terminating the reaction. The solvent was removed by distillation under reduced pressure to obtain a hyperbranched organosilicon crosslinking agent C-2 with a hydrogen content of 1.62 mmol / g.

[0021] Example 3 Preparation of Hyperbranched Organosilicon Crosslinking Agent C-3 50g of side hydrogenated silicone oil (hydrogen content 0.9wt%, molecular weight 2000) was diluted 1 times with toluene for standby use. 83.9g of tetramethyl divinyl disiloxane was added to the reaction bottle, and then 0.03g of platinum-divinyl tetramethyl disiloxane complex (Pt 20wt%) was added, mixed evenly and diluted 1 times with toluene, stirred evenly and heated to 50°C, then the mixture obtained in the previous step was slowly added dropwise, the reaction temperature was controlled to be less than 70°C, and after the addition was completed, the reaction was kept warm for 2 hours. 60.4g of 1,1,3,3-tetramethyl disiloxane was added to the reaction bottle, diluted 1 times with toluene, stirred evenly and heated to 50°C, then the mixture obtained in the previous step was slowly added dropwise, the reaction temperature was controlled to be less than 70°C, and after the addition was completed, the reaction was kept warm for 2 hours.

[0022] 5.7 g of allyl glycidyl ether, 6.4 g of n-butyl acrylate, 12.4 g of 3-(methacryloyloxy)propyl trimethoxysilane, and 67.1 g of tetramethyl divinyl disiloxane were mixed evenly, diluted 1 time with toluene, heated to 50°C, and slowly added the mixture obtained in the first step. After the addition was completed, the temperature was raised to 100°C, and the reaction was kept warm for 4 hours before terminating the reaction. The solvent was removed by distillation under reduced pressure to obtain a hyperbranched organosilicon crosslinking agent C-3 with a vinyl content of 1.05 mmol / g.

[0023] Example 4 Preparation of Hyperbranched Organosilicon Crosslinking Agent C-4 Dilute 500g of end-side vinyl silicone oil (vinyl content 0.7wt%, molecular weight 20,000) with toluene by 2 times, then add 0.14g of platinum-divinyltetramethyldisiloxane complex (Pt 20wt%), mix well and set aside. Add 17.5g of 1,1,3,3-tetramethyldisiloxane to the reaction bottle, dilute it by 1 times with toluene, stir well and heat to 40°C, then slowly drop the mixture obtained in the previous step, control the reaction temperature to <70°C, and keep warm for 2 hours after the addition is complete. Add 24.2g of tetramethyldivinyldisiloxane to the reaction bottle, dilute it by 1 times with toluene, stir well and heat to 50°C, then slowly drop the mixture obtained in the previous step, control the reaction temperature to <70°C, and keep warm for 2 hours after the addition is complete. 17.5 g of 1,1,3,3-tetramethyldisiloxane was added to the reaction bottle and diluted by 1 time with toluene. The mixture was stirred evenly and heated to 50°C. Then the mixture obtained in the previous step was slowly added dropwise while controlling the reaction temperature to <70°C. After the addition was completed, the reaction was kept warm for 2 hours.

[0024] 3.23 g of 1,2-epoxy-4-vinylcyclohexane, 7.7 g of vinyltrimethoxysilane, and 10.5 g of tetramethyldivinyldisiloxane were mixed evenly, diluted 1 time with toluene, heated to 50°C, and slowly added the mixture obtained in the first step. After the addition was completed, the temperature was raised to 100°C, and the reaction was kept warm for 4 hours before terminating the reaction. The solvent was removed by distillation under reduced pressure to obtain a hyperbranched organosilicon crosslinking agent C-4 with a vinyl content of 0.09 mmol / g.

[0025] Example 5 Preparation of Hyperbranched Organosilicon Crosslinking Agent C-5 Dilute 240.5g of 1,3,5,7-tetramethylcyclotetrasiloxane with toluene by 1 time for standby use. Add 186.4g of tetramethyldivinyldisiloxane to the reaction bottle, then add 0.06g of platinum-divinyltetramethyldisiloxane complex (Pt 20wt%), mix well and dilute it by 1 time with toluene, stir well and heat to 50°C, then slowly drop the mixture obtained in the previous step, control the reaction temperature to <70°C, after the addition is complete, keep warm and react for 2 hours. Add 134.32g of 1,1,3,3-tetramethyldisiloxane to the reaction bottle, dilute it by 1 time with toluene, stir well and heat to 50°C, then slowly drop the mixture obtained in the previous step, control the reaction temperature to <70°C, after the addition is complete, keep warm and react for 2 hours. 186.4 g of tetramethyl divinyl disiloxane was added to the reaction bottle, diluted 1 time with toluene, stirred evenly and heated to 50°C, then the mixture obtained in the previous step was slowly added dropwise, the reaction temperature was controlled to be less than 70°C, and after the addition was completed, the reaction was kept warm for 2 hours. 134.32 g of 1,1,3,3-tetramethyl disiloxane was added to the reaction bottle, diluted 1 time with toluene, stirred evenly and heated to 50°C, then the mixture obtained in the previous step was slowly added dropwise, the reaction temperature was controlled to be less than 70°C, and after the addition was completed, the reaction was kept warm for 2 hours.

[0026] 114.14g of allyl glycidyl ether and 148.23g of vinyl trimethoxysilane were mixed evenly, diluted 1 time with toluene, heated to 50°C, and slowly added the mixture obtained in the first step. After the addition was completed, the temperature was raised to 90°C, and the reaction was kept at this temperature for 4 hours before the reaction was terminated. The solvent was removed by distillation under reduced pressure to obtain a hyperbranched organosilicon crosslinking agent C-5 with a hydrogen content of 1.75mmol / g.

[0027] Example 6 Preparation of Hyperbranched Organosilicon Crosslinking Agent C-6 344.66g of tetramethyltetravinylcyclotetrasiloxane was diluted 1 time with toluene, and then 0.07g of platinum-divinyltetramethyldisiloxane complex (Pt 20wt%) was added, mixed evenly and set aside. 134.32g of 1,1,3,3-tetramethyldisiloxane was added to the reaction bottle, diluted 1 time with toluene, stirred evenly and heated to 40°C, then the mixture obtained in the previous step was slowly added dropwise, the reaction temperature was controlled to be less than 70°C, and after the addition was completed, the reaction was kept warm for 2 hours. 186.4g of tetramethyldivinyldisiloxane was added to the reaction bottle, diluted 1 time with toluene, stirred evenly and heated to 50°C, then the mixture obtained in the previous step was slowly added dropwise, the reaction temperature was controlled to be less than 70°C, and after the addition was completed, the reaction was kept warm for 2 hours. 134.32 g of 1,1,3,3-tetramethyldisiloxane was added to the reaction bottle, diluted 1 time with toluene, stirred evenly and heated to 50°C, then the mixture obtained in the previous step was slowly added dropwise, the reaction temperature was controlled to be less than 70°C, and the reaction was kept warm for 2 hours after the addition was completed. 186.4 g of tetramethyldivinyldisiloxane was added to the reaction bottle, diluted 1 time with toluene, stirred evenly and heated to 50°C, then the mixture obtained in the previous step was slowly added dropwise, the reaction temperature was controlled to be less than 70°C, and the reaction was kept warm for 2 hours after the addition was completed. 134.32 g of 1,1,3,3-tetramethyldisiloxane was added to the reaction bottle, diluted 1 time with toluene, stirred evenly and heated to 50°C, then the mixture obtained in the previous step was slowly added dropwise, the reaction temperature was controlled to be less than 70°C, and the reaction was kept warm for 2 hours after the addition was completed.

[0028] 248.35 g of 3-(methacryloyloxy)propyltrimethoxysilane was diluted 1 time with toluene, heated to 50°C, and slowly added dropwise with the mixture obtained in the first step. After the addition was completed, the temperature was raised to 100°C, and the reaction was kept at this temperature for 4 hours before the reaction was terminated. The solvent was removed by distillation under reduced pressure to obtain a hyperbranched organosilicon crosslinking agent C-6 with a hydrogen content of 2.19 mmol / g.

[0029] The components of the high resilience single-component organopolysiloxane compositions of Examples 7-10 and Comparative Examples 1-3 are described as follows, and the specific formula compositions are shown in Table 1.

[0030] Organopolysiloxane A-1 having at least 2 alkenyl groups per molecule: (CH2=CH(CH3)2SiO 1 / 2 )((CH3)2SiO 2 / 2 ) 400 Organopolysiloxane A-2 having at least 2 alkenyl groups per molecule: (CH2=CH(CH3)2SiO 1 / 2 ) 0.2 ((CH3)3SiO 1 / 2 )0.8 (SiO 4 / 2 ) 1.25 Organopolysiloxane B-1 having at least 2 Si-H bonds per molecule: ((CH3)3SiO 1 / 2 )((CH3)HSiO 2 / 2 ) 30 ((CH3)2SiO 2 / 2 ) 50 Organopolysiloxane B-2 having at least 2 Si-H bonds per molecule: ((CH3)2HSiO 1 / 2 )(SiO 4 / 2 ) 0.8 Hydrosilylation catalyst D-1: Platinum-divinyltetramethyldisiloxane complex diluted with dimethylsilicone, Pt content 5000ppm Hydrosilylation catalyst D-2: Capsule-type platinum catalyst, Pt content 5000ppm Fumed silica E-1; Fumed silica treated with hexamethyldisilazane Fumed silica E-2; Fumed silica treated with methyl silicone oil The test items and test conditions are as follows: Thermal curing conditions: Examples 7-10 and Comparative Examples 1-3 were all cured at 150°C for 30 min; Adhesion test: The material is cast aluminum VS cast aluminum. The bonding judgment method is whether the interface is easy to peel off and can be torn off in strips. If the interface is not easy to peel off and difficult to tear off in strips, the bonding is OK; if the interface is easy to peel off and can be torn off in strips, the bonding is NG. Permanent compression loss rate test: Keep the height of the glue strip at 2.0±0.2mm during dispensing, cure at 150℃*30min, and test the height of the glue strip after curing to be h0. Then compress the glue strip with a compression rate of 40% and lock it with screws. Then age it at 125℃*7 days, take it out after aging, remove the screws and pressure, and place it at room temperature for 4h, then test the height of the glue strip to be h1, permanent compression loss rate = (h0- h1) / h0 Table 1 Formulation composition and performance of Examples 7-10 and Comparative Examples 1-3

[0031] From the test results in Table 1, it can be seen that, compared with Comparative Examples 1-2, Examples 7-10, the hyperbranched organosilicon crosslinking agent of the present invention has a more obvious effect on improving the compression rebound performance (permanent compression loss rate %), and at the same time has a better bonding effect on the bonding interface. In addition, from the results of Comparative Examples 2 and 1, it can be seen that the addition of conventional coupling agents has a negative effect on compression rebound, and the introduction of groups that promote the bonding interface into the hyperbranched organosilicon crosslinking agent also successfully avoids the negative impact of the introduction of conventional coupling agents on compression rebound.

Claims

1. A high resilience one-component organopolysiloxane composition comprises the following components (A)-(E): (A) 5-80 parts of an organopolysiloxane having at least 2 alkenyl groups per molecule; (B) 0-10 parts of an organopolysiloxane having at least 2 Si-H bonds per molecule; (C) 0-60 parts of a hyperbranched organosilicon crosslinking agent; (D) 0-1 part of a hydrosilylation catalyst; and (E) 10-40 parts of fumed silica.

2. A high resilience one-component organopolysiloxane composition according to claim 1, characterized in that: The component (A) is an organopolysiloxane having at least 2 alkenyl groups per molecule, and its general structural formula is (R 1 R 2 2SiO 1 / 2 )(R 1 R 2 SiO 2 / 2 ) a (R 2 SiO 3 / 2 ) b (SiO 4 / 2 ) c ; a = 0~500 (excluding 0), b = 0~2, c = 0~2, a+b+c = 1~500; where R 1 , R 2 Each independently represents an unsubstituted or substituted monovalent hydrocarbon group, preferably a group having 1 to 6 carbon atoms.

3. A high resilience one-component organopolysiloxane composition according to claim 1, characterized in that: The component (B) is an organopolysiloxane having at least 2 Si-H bonds per molecule, and its general structural formula is (R 3 R 4 2SiO 1 / 2 )(R 3 R 4 SiO 2 / 2 ) m (R 5 SiO 3 / 2 ) n (SiO 4 / 2 ) x , m=0~100, n=0~3, x=0~2, m+n+x=0.5~100; where R 3 , R 4 , R 5 Each independently represents an unsubstituted or substituted monovalent hydrocarbon group, preferably a group having 1 to 6 carbon atoms.

4. A high resilience one-component organopolysiloxane composition according to claim 1, characterized in that: The component (C) is a hyperbranched organosilicon crosslinking agent, and its chemical structure can be expressed as: ; wherein core is one of 1,3,5,7-tetramethylcyclotetrasiloxane, tetraepoxycyclohexylethyl 2,4,6,8-tetramethylcyclotetrasiloxane, 1,3,5,7,9-pentamethylcyclopentasiloxane, pentamethylpentavinylcyclopentasiloxane, tetramethyltetravinylcyclotetrasiloxane, octavinyl-POSS, side vinyl silicone oil, side hydrogen-containing silicone oil, terminal side vinyl silicone oil, and terminal side hydrogen-containing silicone oil; the number of vinyl or Si-H groups in each molecule of the side vinyl silicone oil, side hydrogen-containing silicone oil, terminal side vinyl silicone oil, and terminal side hydrogen-containing silicone oil is ≥3.

5. The high resilience one-component organopolysiloxane composition according to claim 1, characterized in that: The preparation method of the component (C) hyperbranched organosilicon crosslinking agent is: When the active functional group of the core is vinyl: ① dilute a certain amount of the raw material representing the core with toluene by 1-3 times, then add a certain proportion of platinum catalyst, mix well and set aside; ② add a certain amount of 1,1,3,3-tetramethyldisiloxane to the reaction bottle, dilute it with toluene by 1-3 times, stir well and heat to 40-60°C, then slowly drop the mixture obtained in the previous step, control the reaction temperature to <70°C, and after the dropwise addition is completed, keep the temperature for reaction for 2 hours; ③ add a certain amount of tetramethyldivinyldisiloxane to the reaction bottle, dilute it with toluene by 1-3 times, stir well and heat to 40-60°C, then add the mixture obtained in the previous step The mixture is slowly added dropwise, and the reaction temperature is controlled to be less than 70°C. After the addition is completed, the mixture is kept warm for 2 hours; steps ② and ③ are repeated until the target y value is obtained; when y=0 and 1, only ①→② is performed, and ③ is not required; when y=2 and 3, ①→②→③→② is required; when y=4 and 5, ①→②→③→②→③→② is required; after the repeated reaction of ④ is completed, a certain amount of the end-capping agent is heated to 40-60°C and diluted 1-3 times with toluene, and the mixture obtained in the first step is slowly added dropwise. After the addition is completed, the temperature is raised to 90-100°C, and the mixture is kept warm for 4 hours, and then the reaction is terminated; the solvent is removed by distillation under reduced pressure to obtain (C) a hyperbranched organosilicon crosslinking agent; When the active functional group of the core is Si-H, the platinum catalyst is mixed in step ③; after the reaction of step ①, step ③ is performed first, and then step ② is performed until the target y value is obtained; when y=1 and 2, ①→③→② is required; when y=3 and 4, ①→③→②→③→② is required; when y=5, ①→③→②→③→②→③ is required; after the repeated reaction of ④ is completed, a certain amount of the end-capping agent toluene diluted mixture heated to 40-60°C is slowly added dropwise to the mixture obtained in the first step, and after the addition is completed, the temperature is raised to 90-100°C, and the reaction is kept warm for 4 hours, and then the reaction is terminated; the solvent is removed by distillation under reduced pressure to obtain (C) a hyperbranched silicone crosslinking agent; The amount of the platinum catalyst added is 5-50ppm of the total weight of all raw materials participating in the reaction except toluene; the end-capping agent is one or more of tetramethyl divinyl disiloxane, 1,2-epoxy-4-vinyl cyclohexane, allyl glycidyl ether, n-butyl acrylate, and 3-(methacryloyloxy)propyl trimethoxysilane; When octavinyl-POSS is used as the core, the amount of toluene added is more than 10 times that of octavinyl-POSS; when repeating reaction ② or ③, the amount of raw materials added is such that the ratio of vinyl to Si-H is 1:1; in the final step ④, the amount of capping agent added is such that the ratio of vinyl to Si-H is 1~1.2:

1.

6. The high resilience one-component organopolysiloxane composition according to claim 1, characterized in that: The hydrosilylation catalyst of component (D) is one or a mixture of platinum chloride, alcohol-modified platinum chloride, a complex of platinum chloride and diene, a platinum-olefin complex, a platinum-carbonyl complex such as platinum bis(acetoacetate) or platinum bis(acetylacetone), a platinum chloride-alkenylsiloxane complex such as platinum chloride-divinyltetramethyldisiloxane complex or platinum chloride-tetravinyltetramethylcyclotetrasiloxane, a platinum-alkenylsiloxane complex such as platinum-divinyltetramethyldisiloxane complex or platinum-tetravinyltetramethylcyclotetrasiloxane, a complex between platinum chloride and acetylene alcohol, and a capsule-type platinum catalyst.

7. The high resilience one-component organopolysiloxane composition according to claim 1, characterized in that: The component (E) fumed silica is fumed silica treated with a treating agent; the treating agent is one or a mixture of trimethylchlorosilane, dimethyldichlorosilane, dimethyldiethoxysilane, methyltrichlorosilane, trimethylethoxysilane, vinyltrimethoxysilane, γ-aminopropyltriethoxysilane, methyl silicone oil, ethyl silicone oil, tolyl silicone oil, methyl hydrogen silicone oil, ethyl hydrogen silicone oil, hydroxyl-containing silicone oil, and hexamethyldisilazane.

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