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

Abstract

The present invention aims to provide a high-resilience single-component organopolysiloxane composition and a preparation method therefor. The high-resilience single-component organopolysiloxane composition is suitable for sealing bonding for various automobile, industrial and electronic parts and components, especially for a sealing bonding scene where a formed-in-place gasket (CIPG) is applied. The high-resilience single-component organopolysiloxane composition of the present invention comprises at least the following components (A)-(E): (A) an organopolysiloxane having at least two alkenyl groups per molecule; (B) an organopolysiloxane having at least two Si-H bonds per molecule; (C) a hyperbranched organosilicon cross-linking agent; (D) a hydrosilylation catalyst; and (E) fumed white carbon black. In the present invention, the hyperbranched organosilicon cross-linking agent is prepared by means of a hydrosilylation reaction, wherein a multifunctional organosilicon molecule acts as a core basis of the hyperbranched structure. On the one hand, by means of the hyperbranched structure, the spatial distance between cross-linking points is increased, so that the cured polysiloxane composition has good resilience performance; on the other hand, an active group for increasing interface bonding is introduced into the hyperbranched organosilicon cross-linking agent, so that the hyperbranched organosilicon cross-linking agent also has good bonding performance on an interface of a material while a cross-linking curing effect is achieved.

Description

A high-resilience single-component organopolysiloxane composition and preparation method thereof Technical Field

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

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

[0003] Faced with the current requirements of precision, airtightness, and integration in the new energy vehicle industry, the design of new automotive sealed connectors for automotive motors, electronic controls, oil pump controllers, and EHPS steering pumps is trending towards larger sizes and more complex structures. A new automotive connector sealing technology based on the CIPG process has been proposed. This sealing product also demonstrates high and low temperature resistance, high pressure resistance, and high humidity resistance, making it a key future development and application direction for automotive sealed connectors.

[0004] The present invention aims to develop a single-component organopolysiloxane composition with high resilience after curing, and its preparation method. The composition is suitable for sealing and bonding various automotive, industrial, and electronic components, particularly for sealing and bonding applications involving formed-in-place gaskets (CIPGs). The design of the molecular structure of a hyperbranched organosilicone crosslinker increases the spatial distance between crosslinking points, resulting in excellent resilience in the cured polysiloxane composition. Furthermore, active groups that enhance interfacial adhesion are introduced into the hyperbranched organosilicone crosslinker, providing both crosslinking and curing while also providing excellent adhesion to material interfaces.

[0005] Summary of the Invention

[0006] The object of the present invention is to provide a single-component organopolysiloxane composition with high rebound 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). 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 multiple functions as an active crosslinker that can participate in the hydrosilylation reaction, and also contains active groups that can increase interfacial adhesion. 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 rebound properties; on the other hand, active groups that increase interfacial adhesion are introduced into this hyperbranched organosilicon crosslinker, which not only plays a crosslinking and curing role, but also has good adhesion properties to the material interface.

[0007] The high-resilience one-component organopolysiloxane composition of the present invention comprises at least the following components (A) to (E):

[0008] (A) 5-80 parts of an organopolysiloxane having at least 2 alkenyl groups per molecule;

[0009] (B) 0-10 parts of an organopolysiloxane having at least 2 Si—H bonds per molecule;

[0010] (C) 0-60 parts of a hyperbranched organosilicon crosslinking agent;

[0011] (D) 0-1 part of a hydrosilylation catalyst;

[0012] (E) 10-40 parts of fumed silica;

[0013] 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 2Each independently represents an unsubstituted or substituted monovalent hydrocarbon group. As a monovalent hydrocarbon group, a group having 1 to 10 carbon atoms, particularly preferably 1 to 6 carbon atoms, can be specifically listed: 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 groups, etc., such as chloromethyl, cyanoethyl, etc. More preferably, it is preferably selected from a group 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.

[0014] The component (B) is an organopolysiloxane having at least two 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 independently represents an unsubstituted or substituted monovalent hydrocarbon group. As a monovalent hydrocarbon group, a group having 1 to 10 carbon atoms, particularly preferably 1 to 6 carbon atoms, can be specifically listed: 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 groups, etc., such as chloromethyl, cyanoethyl, etc. More preferably, it is preferably selected from groups 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.

[0015] The component (C) is a hyperbranched organosilicon crosslinker, and its chemical structural formula can be expressed as:

[0016] Among them, y=an integer from 0 to 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; on the other hand, the chain segment is too long, which has no substantial significance for improving the rebound.

[0017] 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 in the present invention specifically refer to the number of vinyl or Si-H groups in each molecule ≥3.

[0018] The preparation method of the component (C) hyperbranched organosilicon crosslinking agent is:

[0019] 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 add the mixture obtained in the previous step dropwise, control the reaction temperature to <70°C, after the addition is complete, keep the temperature and react 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 dropwise, control the reaction temperature to <70°C, after the addition is complete, keep the temperature and react for 2 hours; The mixture is slowly added dropwise, and the reaction temperature is controlled to be less than 70°C. After the addition is completed, the reaction 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 ④ is completed, a certain amount of end-capping agent heated to 40-60°C is 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 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 organosilicon crosslinking agent;

[0020] When the active functional group of the core is Si-H, the platinum catalyst is mixed in step ③; after the reaction in step ①, step ③ is carried out first, and then step ② is carried out until the target y value is obtained; when y=1 and 2, the steps ①→③→② are required; when y=3 and 4, the steps ①→③→②→③→② are required; when y=5, the steps ①→③→②→③→②→③ are required; after the repeated reaction ④ is completed, the mixture obtained in the first step is slowly added dropwise to a certain amount of a dilute mixture of the end-capping agent toluene heated to 40-60°C, and after the addition is complete, the mixture is heated to 90-100°C, 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 crosslinker;

[0021] 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 end-capping agent added is such that the ratio of vinyl to Si-H is 1 to 1.2:1.

[0022] The added amount of the platinum catalyst is 5-50 ppm 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.

[0023] The component (D) hydrosilylation catalyst can be selected from platinum-based catalysts, rhodium-based catalysts or palladium-based catalysts, and is preferably based on platinum-based catalysts in view of catalytic activity. The platinum-based catalyst can be a complex of platinum chloride, alcohol-modified platinum chloride, platinum chloride and diene, platinum-olefin complex, platinum-carbonyl complex such as platinum bis (acetoacetate) or platinum bis (acetylacetone), platinum chloride-alkenylsiloxane complex such as platinum chloride-divinyltetramethyldisiloxane complex or platinum chloride-tetravinyltetramethylcyclotetrasiloxane, a mixture of one or more of 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 etc.

[0024] The component (E) fumed silica is preferably fumed silica treated with a treating agent, and the treating agent can 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 silicone oil, hexamethyldisilazane, etc.

[0025] Based on this patent invention, adjustments can be made to meet the corresponding application requirements: for example, adding fluorescent agents, carbon black, color paste, titanium dioxide, etc. to adjust the appearance and detection function; adding silica powder, etc. for reinforcement; adding aluminum oxide, zinc oxide, magnesium oxide, aluminum hydroxide, etc. to improve thermal conductivity and flame retardancy; adding inhibitors, etc. to adjust storage period and working time, etc. The commonly used high-temperature treatment method can also be used to enhance the interaction between silicone oil or resin matrix and fumed silica to enhance the reinforcement effect;

[0026] The present invention provides a single-component organopolysiloxane composition with high resilience after curing and a preparation method thereof, which is suitable for the sealing and bonding of various automotive, industrial and electronic components, especially for the sealing and bonding scenarios of in-situ formed sealing gaskets (CIPG). The beneficial effects of the present invention are: ① Using multifunctional organosilicon molecules as the core basis of the hyperbranched structure, a hyperbranched organosilicon crosslinker is prepared by a 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 rebound properties, 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 the material 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 crosslinker of the present invention has multiple functions as an active crosslinker that can participate in the hydrosilylation reaction, and also contains active groups that can increase interfacial adhesion, thereby achieving the three-in-one effect of not reducing the bulk strength, enhancing the rebound and improving the bonding performance. DETAILED DESCRIPTION

[0027] 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.

[0028] Example 1 Preparation of hyperbranched organosilicon crosslinking agent C-1:

[0029] 500g of end-side vinyl silicone oil (0.5wt% vinyl content, 60,000 molecular weight) was diluted 3-fold with toluene, followed by the addition of 0.015g of platinum-divinyltetramethyldisiloxane complex (Pt 20wt%), mixed thoroughly, and set aside. 12.5g of 1,1,3,3-tetramethyldisiloxane was added to the reaction flask and diluted 1-fold with toluene. The mixture was stirred thoroughly and heated to 40°C. The mixture obtained in the previous step was then slowly added dropwise, maintaining the reaction temperature below 70°C. After the addition was complete, the reaction was incubated for 2 hours.

[0030] 3.75g of vinyltrimethoxysilane was diluted 1 / 2 with toluene, heated to 50°C, and slowly added dropwise to the mixture obtained in the first step. After the addition was complete, the temperature was raised to 90°C and allowed to react for 4 hours before terminating the reaction. The solvent was removed by distillation under reduced pressure to obtain hyperbranched organosilicon crosslinker C-1, with a hydrogen content of 0.13 mmol / g.

[0031] Example 2 Preparation of Hyperbranched Organosilicon Crosslinker C-2

[0032] 500g of octavinyl-POSS was diluted 12-fold with toluene, followed by the addition of 0.1g of platinum-divinyltetramethyldisiloxane complex (Pt 20wt%), mixed thoroughly, and set aside. 848.7g of 1,1,3,3-tetramethyldisiloxane was added to a reaction flask and diluted 2-fold with toluene. The mixture was stirred thoroughly and heated to 60°C. The mixture obtained in the previous step was then slowly added dropwise, maintaining the reaction temperature below 70°C. After the addition was complete, the reaction was incubated for 2 hours.

[0033] 117.1 g of vinyltrimethoxysilane, 90.17 g of allyl glycidyl ether, and 392.4 g of 3-(methacryloyloxy)propyltrimethoxysilane were mixed uniformly, diluted 100% with toluene, and slowly added dropwise to the mixture obtained in the first step at a temperature of 50°C. After the addition was complete, the mixture was heated to 100°C and allowed to react for 4 hours before terminating the reaction. The solvent was removed by distillation under reduced pressure to obtain hyperbranched organosilicon crosslinker C-2, which had a hydrogen content of 1.62 mmol / g.

[0034] Example 3 Preparation of Hyperbranched Organosilicon Crosslinker C-3

[0035] 50g side hydrogenated silicone oil (hydrogen content 0.9wt%, molecular weight 2000) is diluted 1 times with toluene for use. 83.9g tetramethyldivinyldisiloxane is added in the reaction flask, then 0.03g of platinum-divinyltetramethyldisiloxane complex (Pt 20wt%) is added, mixed and diluted 1 times with toluene, stirred and warmed to 50 ℃, then the mixture obtained in the previous step is slowly dripped, controlled reaction temperature < 70 ℃, after dropwising, insulation reaction 2 hours. 60.4g 1,1,3,3-tetramethyldisiloxane is added in the reaction flask, and diluted 1 times with toluene, stirred and warmed to 50 ℃, then the mixture obtained in the previous step is slowly dripped, controlled reaction temperature < 70 ℃, after dropwising, insulation reaction 2 hours.

[0036] 5.7 g of allyl glycidyl ether, 6.4 g of n-butyl acrylate, 12.4 g of 3-(methacryloyloxy)propyltrimethoxysilane, and 67.1 g of tetramethyldivinyldisiloxane were mixed uniformly, diluted 100% with toluene, and slowly added dropwise to the mixture obtained in the first step at a temperature of 50°C. After the addition was complete, the temperature was raised to 100°C and the mixture was kept at this temperature for 4 hours before terminating the reaction. The solvent was removed by distillation under reduced pressure to obtain hyperbranched organosilicon crosslinker C-3, with a vinyl content of 1.05 mmol / g.

[0037] Example 4 Preparation of Hyperbranched Organosilicon Crosslinker C-4

[0038] 500g end side vinyl silicone oil (vinyl content 0.7wt%, molecular weight 20,000) is diluted 2 times with toluene, then add the platinum-divinyltetramethyldisiloxane complex (Pt 20wt%) of 0.14g, stand-by after mixing.17.5g 1,1,3,3-tetramethyldisiloxane is joined in the reaction flask, and diluted 1 times with toluene, stir and be warming up to 40 ℃, subsequently the mixture obtained in the previous step is slowly dripped, controlled reaction temperature<70 ℃, after dropwising, insulation reaction 2 hours.24.2g tetramethyldivinyldisiloxane is joined in the reaction flask, and diluted 1 times with toluene, stir and be warming up to 50 ℃, subsequently the mixture obtained in the previous step is slowly dripped, controlled reaction temperature<70 ℃, after dropwising, insulation reaction 2 hours. 17.5 g of 1,1,3,3-tetramethyldisiloxane was added to the reaction flask and diluted with toluene by 1 time. The mixture was stirred evenly and heated to 50°C. The mixture obtained in the previous step was then slowly added dropwise while controlling the reaction temperature to <70°C. After the addition was complete, the reaction was kept warm for 2 hours.

[0039] 3.23 g of 1,2-epoxy-4-vinylcyclohexane, 7.7 g of vinyltrimethoxysilane, and 10.5 g of tetramethyldivinyldisiloxane were mixed uniformly, diluted 100% with toluene, and slowly added dropwise to the mixture obtained in the first step at a temperature of 50°C. After the addition was complete, the temperature was raised to 100°C and the reaction was maintained for 4 hours before termination. The solvent was removed by distillation under reduced pressure to obtain hyperbranched organosilicon crosslinker C-4, with a vinyl content of 0.09 mmol / g.

[0040] Example 5 Preparation of Hyperbranched Organosilicon Crosslinker C-5

[0041] 240.5g 1,3,5,7-tetramethylcyclotetrasiloxane was diluted 1-fold with toluene for later use. 186.4g tetramethyldivinyldisiloxane was added to a reaction flask, followed by addition of 0.06g of platinum-divinyltetramethyldisiloxane complex (Pt 20wt%), mixed evenly and diluted 1-fold with toluene, stirred evenly and warmed to 50°C, then slowly added dropwise the mixture obtained in the previous step, controlling the reaction temperature to <70°C. After completion of the addition, the mixture was incubated for 2 hours. 134.32g 1,1,3,3-tetramethyldisiloxane was added to a reaction flask, diluted 1-fold with toluene, stirred evenly and warmed to 50°C, then slowly added dropwise the mixture obtained in the previous step, controlling the reaction temperature to <70°C. After completion of the addition, the mixture was incubated for 2 hours. 186.4g of tetramethyldivinyldisiloxane was added to the reaction flask and diluted 1-fold with toluene. The mixture was stirred and heated to 50°C. The mixture obtained in the previous step was then slowly added dropwise, controlling the reaction temperature to <70°C. After the addition was complete, the mixture was kept warm for 2 hours. 134.32g of 1,1,3,3-tetramethyldisiloxane was added to the reaction flask and diluted 1-fold with toluene. The mixture was stirred and heated to 50°C. The mixture obtained in the previous step was then slowly added dropwise, controlling the reaction temperature to <70°C. After the addition was complete, the mixture was kept warm for 2 hours.

[0042] 114.14g of allyl glycidyl ether and 148.23g of vinyltrimethoxysilane were mixed uniformly, diluted 100% with toluene, and slowly added dropwise to the mixture obtained in the previous step at a temperature of 50°C. After the addition was complete, the temperature was raised to 90°C and allowed to react for 4 hours before terminating the reaction. The solvent was removed by distillation under reduced pressure to obtain hyperbranched organosilicon crosslinker C-5, which had a hydrogen content of 1.75 mmol / g.

[0043] Example 6 Preparation of Hyperbranched Organosilicon Crosslinker C-6

[0044] 344.66g tetramethyl tetravinylcyclotetrasiloxane is diluted 1 time with toluene, then 0.07g of platinum-divinyltetramethyldisiloxane complex (Pt 20wt%) is added, mixed and then used. 134.32g 1,1,3,3-tetramethyldisiloxane is added to a reaction flask, diluted 1 time with toluene, stirred and heated to 40°C, then the mixture obtained in the previous step is slowly added dropwise, the reaction temperature is controlled to be less than 70°C, after completion of the addition, the reaction is incubated for 2 hours. 186.4g tetramethyl divinyl disiloxane is added to a reaction flask, diluted 1 time with toluene, stirred and heated to 50°C, then the mixture obtained in the previous step is slowly added dropwise, the reaction temperature is controlled to be less than 70°C, after completion of the addition, the reaction is incubated for 2 hours. 134.32g 1,1,3,3-tetramethyldisiloxane was added to a reaction flask and diluted 1-fold with toluene, stirred and heated to 50°C, then the mixture obtained in the previous step was slowly added dropwise, the reaction temperature was controlled to be <70°C, and after completion of the addition, the reaction was incubated for 2 hours. 186.4g tetramethyldivinyldisiloxane was added to a reaction flask and diluted 1-fold with toluene, stirred and heated to 50°C, then the mixture obtained in the previous step was slowly added dropwise, the reaction temperature was controlled to be <70°C, and after completion of the addition, the reaction was incubated for 2 hours. 134.32g 1,1,3,3-tetramethyldisiloxane was added to a reaction flask and diluted 1-fold with toluene, stirred and heated to 50°C, then the mixture obtained in the previous step was slowly added dropwise, the reaction temperature was controlled to be <70°C, and after completion of the addition, the reaction was incubated for 2 hours.

[0045] 248.35 g of 3-(methacryloyloxy)propyltrimethoxysilane was diluted 1 / 2 with toluene, heated to 50°C, and slowly added dropwise to the mixture obtained in the first step. After the addition was complete, the temperature was raised to 100°C and the mixture was kept at this temperature for 4 hours before terminating the reaction. The solvent was removed by distillation under reduced pressure to obtain hyperbranched organosilicon crosslinker C-6, with a hydrogen content of 2.19 mmol / g.

[0046] The components of the high-resilience single-component organopolysiloxane compositions of Examples 7-10 and Comparative Examples 1-3 are described as follows. The specific formulation compositions are shown in Table 1.

[0047] 1) Organopolysiloxane A-1 having at least 2 alkenyl groups per molecule: (CH2=CH(CH3)2SiO 1 / 2 )((CH3)2SiO 2 / 2 ) 400

[0048] 2) Organopolysiloxane A-2 having at least 2 alkenyl groups per molecule: (CH2=CH(CH3)2SiO 1 / 2 ) 0.2 ((CH3)3SiO1 / 2 ) 0.8 (SiO 4 / 2 ) 1.25

[0049] 3) Organopolysiloxane B-1 having at least two Si-H bonds per molecule: ((CH3)3SiO 1 / 2 )((CH3)HSiO 2 / 2 ) 30 ((CH3)2SiO 2 / 2 ) 50

[0050] 4) Organopolysiloxane B-2 having at least two Si-H bonds per molecule: ((CH3)2HSiO 1 / 2 )(SiO 4 / 2 ) 0.8

[0051] 5) Hydrosilylation catalyst D-1: Platinum-divinyltetramethyldisiloxane complex diluted with dimethyl silicone oil, Pt content 5000ppm

[0052] 6) Hydrosilylation catalyst D-2: Capsule-type platinum catalyst with a Pt content of 5000 ppm

[0053] 7) Fumed silica E-1; Fumed silica treated with hexamethyldisilazane

[0054] 8) Fumed silica E-2; Fumed silica treated with methyl silicone oil

[0055] The test items and test conditions are as follows:

[0056] 1) Thermal curing conditions: Examples 7-10 and Comparative Examples 1-3 were all cured at 150°C for 30 minutes;

[0057] 2) Adhesion test: The material is cast aluminum vs. cast aluminum. Adhesion is judged by 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 adhesion is OK. If the interface is easy to peel off and can be torn off in strips, the adhesion is NG.

[0058] 3) Permanent Compression Loss Test: Dispense the adhesive strip to maintain a height of 2.0 ± 0.2 mm. Cure at 150°C for 30 minutes. After curing, measure the strip height at h0. Then compress the strip to 40% compression and secure with screws. Aging is then performed at 125°C for 7 days. Remove the strip, remove the screws and pressure, and allow it to sit at room temperature for 4 hours. Then measure the strip height at h1. Permanent Compression Loss = (h0 - h1) / h0.

[0059] Table 1 Formulation composition and performance of Examples 7-10 and Comparative Examples 1-3

[0060] The test results in Table 1 show that, compared to Comparative Examples 1-2, Examples 7-10 demonstrate a significant improvement in compression rebound performance (permanent compression loss %), while also providing a relatively good bonding effect at the bonding interface. Furthermore, the results of Comparative Examples 2 and 1 show that the addition of a conventional coupling agent negatively impacts compression rebound. The introduction of groups that promote bonding interfaces into the hyperbranched silicone crosslinker successfully mitigates the negative impact of conventional coupling agents on compression rebound.

Claims

1. A high resilience one-component organopolysiloxane composition comprising 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. The 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 structural formula can be expressed as: The core is 1,3,5,7-tetramethylcyclotetrasiloxane, tetraepoxycyclohexylethyl 2,4,6,8-tetramethylcyclotetrasiloxane, 1,3,5,7,9-pentamethylcyclopentasiloxane, pentamethylpentavinylcyclopentasiloxane, tetramethyltetravinylcyclotetrasiloxane, One of 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 heated to 40-60°C is 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 organosilicon 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 to 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 a 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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