Silicone weather-proof sealant and preparation method thereof

Abstract

The invention discloses a silicone weather-proof adhesive and a preparation method thereof, and relates to the technical field of silicone adhesives. The silicone weather-resistant sealant comprises a basic rubber material, a plasticizer, silanol phenyl POSS (Polyhedral Oligomeric Silsesquioxane), a dealcoholization type cross-linking agent, a reinforcing filler, a titanium complex, a silane coupling agent and a curing accelerator. Wherein the basic sizing material is alpha, omega-dihydroxy polydimethylsiloxane, the plasticizer comprises dimethyl silicone oil, and the curing accelerator is C12-C14 fatty alcohol-polyoxyethylene ether. According to the technical scheme, the prepared silicone weather-resistant sealant has good heat aging resistance and low temperature resistance, can still keep higher mechanical properties and bonding strength in a high-temperature environment for a long time, has a wider temperature application range, and can keep excellent dynamic sealing durability in a large-temperature-difference environment for a long time.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of silicone glue, in particular to a silicone weather-resistant glue and a preparation method thereof. BACKGROUND

[0002] As a kind of single-component or double-component room temperature curing elastic sealing material, silicone weather-resistant glue has become the core material in the fields of building curtain wall, door and window sealing, photovoltaic module packaging, industrial equipment gap filling and the like, with the characteristics of excellent resistance to ultraviolet light, ozone and good bonding compatibility, and its core function is to form an elastomer through curing, buffer the thermal stress of bonding base material due to temperature change, and block water vapor and air penetration to ensure the sealing and durability of the overall bonding structure.

[0003] From the formula system, the existing silicone weather-resistant glue is mainly based on polydimethylsiloxane as the system basis, with calcium carbonate, carbon black and other filler agents, and conventional crosslinking agents such as methyltrimethoxysilane to form a basic sealing structure. Although this formula system of silicone weather-resistant glue performs well in conventional environments, its performance has significant limitations when facing large and high-frequency temperature difference cycles, and it is difficult to maintain stable elasticity and bonding performance at the same time for a long time in a wide temperature range. Specifically, at extremely low temperatures, the glue is prone to hardening and embrittlement due to the freezing of molecular chain segments, and loses displacement compensation ability; at high temperatures, the thermal oxidation risk of organic side groups will accelerate the aging of the glue. More prominent is that the severe temperature difference alternating stress will continuously impact the molecular network of the glue and the connecting interface with the base material, and cause irreversible fatigue damage, such as increased permanent deformation of the silicone weather-resistant glue, decreased cohesive strength, and even bonding failure. Therefore, developing a silicone weather-resistant glue that can maintain excellent dynamic sealing durability in a large temperature difference environment is of great significance to the development of current silicone weather-resistant glue. SUMMARY

[0004] In order to expand the temperature range of silicone weather-resistant glue and ensure that the silicone weather-resistant glue can maintain excellent dynamic sealing durability for a long time in extreme environmental temperature and large temperature difference, the present application provides a silicone weather-resistant glue and a preparation method thereof.

[0005] In a first aspect, the present application provides a silicone weather-resistant glue using the following technical solution: A silicone weather-resistant glue, comprising the following raw materials by weight: Base glue: 100 parts; Plasticizer: 15-25 parts; Silanol phenyl POSS: 0.5-1 part; De-alcohol crosslinking agent: 8-12 parts; Reinforcing filler: 35-50 parts; Titanium complex: 1.6-2 parts; Silane coupling agent: 1.5-1.8 parts; Curing accelerator: 0.9-1.2 parts; The base gum is α, ω-dihydroxy polydimethylsiloxane, the plasticizer comprises dimethyl silicone oil, and the curing accelerator is C12-C14 fatty alcohol polyoxyethylene ether.

[0006] By adopting the above technical scheme, the phenyl POSS is introduced, the phenyl and nanoscale rigid sites are introduced into the crosslinked network of the silicone weather-resistant adhesive, the overall regularity and crystallinity are destroyed, the heat aging resistance and low temperature resistance are improved, the silicone weather-resistant adhesive can maintain high mechanical properties and bonding strength for a long time in a high temperature environment, the silicone weather-resistant adhesive can also have high low temperature flexibility after multiple extreme high-low temperature cycles, has a wider temperature application range, and is beneficial to maintaining excellent dynamic sealing durability of the silicone weather-resistant adhesive in a large temperature difference environment. At the same time, the introduction of C12-C14 fatty alcohol polyoxyethylene ether can effectively solve the problems of curing difficulty and slow curing speed of the silicone weather-resistant adhesive after the introduction of the phenyl POSS, and is beneficial to ensuring that the silicone weather-resistant adhesive has excellent temperature difference resistance while achieving normal curing.

[0007] Optionally, the viscosity of the base gum is 20000-80000 mPa·s, and the viscosity of the dimethyl silicone oil is 350-500 mPa·s.

[0008] By adopting the above technical scheme, the silicone weather-resistant adhesive with high comprehensive performance can be prepared, and the silicone weather-resistant adhesive also has good extrudability and high use viscosity.

[0009] Optionally, the phenyl POSS is one of trisilanol phenyl POSS or tetrasilanol phenyl POSS.

[0010] By adopting the above technical scheme, the trisilanol phenyl POSS and the tetrasilanol phenyl POSS both have silanol groups and phenyl groups, the phenyl POSS is introduced into the crosslinked network of the silicone weather-resistant adhesive through the moisture curing of the silanol groups and the matrix resin and the crosslinking agent, and then nanoscale rigid sites are formed in the crosslinked network, which is beneficial to destroying the regularity and crystallinity of the silicone weather-resistant adhesive, and greatly improving the mechanical strength, heat aging resistance and temperature difference resistance of the silicone weather-resistant adhesive.

[0011] Optionally, the plasticizer further comprises long-chain alkyl modified phenyl silicone oil, and the mass ratio of the dimethyl silicone oil to the long-chain alkyl modified phenyl silicone oil is (4-9):1, wherein the long-chain alkyl modified phenyl silicone oil is prepared by reacting long-chain α-olefin with phenyl hydrogen-containing silicone oil.

[0012] By adopting the technical scheme, the long-chain alkyl modified phenyl silicone oil is introduced, which is conducive to further improving the heat aging resistance and temperature difference resistance of the silicone weather-resistant adhesive, and controlling the mass ratio of the dimethyl silicone oil and the long-chain alkyl modified phenyl silicone oil in the range of (4-9):1, which can effectively ensure the curing efficiency of the silicone weather-resistant adhesive and prevent the curing difficulty of the silicone weather-resistant adhesive in a low-temperature environment.

[0013] Optionally, the curing accelerator specifically is a combination of MOA-4, MOA-5 and MOA-9, wherein the mass ratio of the MOA-4, the MOA-5 and the MOA-9 is 1:0.5:(1-1.5).

[0014] By adopting the technical scheme, when the curing accelerator is a combination of MOA-4, MOA-5 and MOA-9 mixed in a mass ratio of 1:0.5:(1-1.5), the curing accelerator can be fully dispersed in the silicone weather-resistant adhesive through the long-chain fatty alcohol groups thereof, and the overall moisture absorption of the silicone weather-resistant adhesive can be improved by the hydrophilicity of the EO chain segment, so that the silicone weather-resistant adhesive can be continuously and fully cured by the moisture in the air, and the overall curing efficiency of the silicone weather-resistant adhesive can be improved.

[0015] Optionally, the dealcoholized crosslinking agent is at least one of methyltrimethoxysilane or ethyltrimethoxysilane.

[0016] Optionally, the reinforcing filler is a combination of fumed silica and light calcium carbonate, and the mass ratio of the fumed silica and the light calcium carbonate is (5-7):(2-3).

[0017] By adopting the technical scheme, the mechanical properties of the silicone weather-resistant adhesive can be improved.

[0018] Optionally, the titanium complex is a combination of a primary titanium complex and a secondary titanium complex, and the mass ratio of the primary titanium complex and the secondary titanium complex is 1:(1-1.5).

[0019] By adopting the technical scheme, the catalytic system of the primary titanium complex and the secondary titanium complex is used, and compared with the traditional catalytic system, the catalytic effect of the titanium complex is better, and the overall curing efficiency of the silicone weather-resistant adhesive can be improved.

[0020] Optionally, the silane crosslinking agent is silane coupling agent KH-550.

[0021] In a second aspect, the application provides a preparation method of a silicone weather-resistant adhesive, which adopts the following technical scheme: A preparation method of a silicone weather-resistant adhesive, comprising the following steps: S1, after the base glue, plasticizer is mixed and stirred uniformly, then the reinforcing filler and silanol phenyl POSS are added, continuous stirring and uniform dispersion are carried out, and the base glue is obtained; S2, the base glue obtained in S1 is heated to 105-110 DEG C and vacuum dewatering is carried out for 5-10 min, then it is cooled to room temperature, the silane coupling agent and the dealcoholization crosslinking agent are added, the vacuum state is maintained and stirring is uniform, and the mixed glue is prepared; S3, the titanium complex and the curing accelerator are added to the mixed glue obtained in S2, the vacuum state is maintained and stirring is uniform, the target glue is prepared, finally dry inert gas is introduced to balance the vacuum, the target glue is extruded and sealed under the dry inert atmosphere by using a press, and the silicone weather-resistant glue is obtained.

[0022] By using the above technical scheme, the raw materials are added in steps and stirred and mixed, which can prevent the hydrolysis reaction of the titanium complex catalyzed dealcoholization crosslinking agent during stirring, ensure that the overall reaction activity will not be lost during preparation. Moreover, extrusion and sealing under a dry inert atmosphere can also prevent the reaction of the titanium complex catalyzed dealcoholization crosslinking agent during long-term storage, which is beneficial to prolong the storage time of the silicone glue. In addition, the preparation method adopted is simple and convenient, and the energy consumption is low, which is beneficial to mass production in factories.

[0023] To sum up, the technical scheme in the application at least has the following beneficial effects: 1. By introducing silanol phenyl POSS into the silicone weather-resistant glue, the heat aging resistance and low temperature resistance of the silicone weather-resistant glue can be improved, the silicone weather-resistant glue can still maintain high mechanical properties and bonding strength under high temperature environment for a long time, and the silicone weather-resistant glue can also have high low temperature flexibility after multiple extreme high-low temperature cycle changes, has a wider temperature application range, and is beneficial to the long-term maintenance of excellent dynamic sealing durability of the silicone weather-resistant glue in a large temperature difference environment.

[0024] 2. By introducing C12-C14 fatty alcohol polyoxyethylene ether into the silicone weather-resistant glue containing silanol phenyl POSS, the problem of difficult curing and slow curing speed of the silicone weather-resistant glue after the introduction of silanol phenyl POSS can be effectively solved, and the silicone weather-resistant glue can be ensured to have excellent temperature difference resistance while realizing normal curing. DETAILED DESCRIPTION

[0025] The application will be further described in detail below in combination with preparation examples, examples and comparative examples. In the preparation examples, examples and comparative examples, part of the raw materials used are as follows: The phenyl hydrogen-containing silicone oil is specifically selected from a phenyl hydrogen-containing silicone oil with a model number of PH212 from Shandong Dayi Chemical Industry Co., Ltd., wherein the active hydrogen content is 0.1%, the phenyl content (mol) is 20%, and the viscosity is 200 mpa·s.

[0026] The trisilanol phenyl POSS and the tetrasilanol phenyl POSS are both selected from Xi'an Qi Yue Bioengineering Co., Ltd., and the model numbers are Q-0000419 and Q-0000420, respectively.

[0027] The titanium complexes are both selected from Shenzhen Fulin New Material Co., Ltd., and the model numbers are FC-161 and FC-162.

[0028] The fumed silica is specifically selected from Hubei Hui Fu Nanometer Material Co., Ltd., and the model number is HB-151; and the light calcium carbonate is specifically selected from Foshan Wugen New Material Co., Ltd., and the model number is VS-600.

[0029] The MOA-4, the MOA-5, and the MOA-9 are all selected from Jiangsu Hai'an Petrochemical Co., Ltd. Preparation Example

[0030]

Preparation Example 1

[0031]

Example 1

[0032] In the present embodiment, the base rubber specifically consists of two different viscosity α, ω-dihydroxy polydimethylsiloxanes, wherein the A material is α, ω-dihydroxy polydimethylsiloxane with a viscosity of 20000 mPa·s, the B material is α, ω-dihydroxy polydimethylsiloxane with a viscosity of 80000 mPa·s, and the mass ratio of the A material to the B material is 1:1, i.e. the base rubber includes 50 kg of the A material and 50 kg of the B material.

[0033] The plasticizer specifically is dimethyl silicone oil, wherein the viscosity of the dimethyl silicone oil is 500 mPa·s.

[0034] The dealcoholization type crosslinking agent specifically is methyl trimethoxysilane.

[0035] The reinforcing filler specifically includes 35 kg of fumed silica and 15 kg of light calcium carbonate.

[0036] The titanium complex specifically includes 0.8 kg of a primary titanium complex and 0.8 kg of a secondary titanium complex.

[0037] The curing accelerator specifically adopts a combination of MOA-4, MOA-5 and MOA-9, wherein the mass ratio of MOA-4, MOA-5 and MOA-9 is 1:0.5:1, i.e. includes 0.36 kg of MOA-4, 0.18 kg of MOA-5 and 0.36 kg of MOA-9.

[0038] A preparation method of a silicone weather-resistant adhesive, comprising the following steps: S1, after mixing and stirring the α, ω-dihydroxy polydimethylsiloxane and the plasticizer uniformly, the reinforcing filler and the trisilanol phenyl POSS are added, and continuous stirring is performed until uniform dispersion is achieved, to obtain a base rubber; S2, the base rubber obtained in S1 is heated to 105°C and vacuum dewatering is performed for 10 min, and after it is cooled to room temperature, the silane coupling agent and the dealcoholization type crosslinking agent are added, and uniform stirring is performed under vacuum, to prepare a mixed rubber; S3, the titanium complex and the curing accelerator are further added to the mixed rubber obtained in S2, and uniform stirring is performed under vacuum, to prepare a target rubber, and finally dry inert gas is introduced to balance the vacuum, and the target rubber is extruded and stored in a sealed state under a dry inert atmosphere, to obtain the silicone weather-resistant adhesive.

[0039]

Embodiment 2

[0040] In the present embodiment, the base gum is specifically composed of two different viscosity α, ω-dihydroxy polydimethylsiloxanes, wherein the A material is α, ω-dihydroxy polydimethylsiloxane with a viscosity of 20000 mPa·s, the B material is α, ω-dihydroxy polydimethylsiloxane with a viscosity of 80000 mPa·s, and the mass ratio of the A material to the B material is 3:1, i.e. the base gum includes 75 kg of the A material and 25 kg of the B material.

[0041] The plasticizer is specifically a combination of dimethyl silicone oil and long-chain alkyl-modified phenyl silicone oil, wherein the viscosity of the dimethyl silicone oil is 500 mPa·s, the long-chain alkyl-modified phenyl silicone oil is specifically prepared by

Preparation Example 1

[0042] The dealcoholization crosslinking agent is specifically ethyl trimethoxysilane.

[0043] The reinforcing filler specifically includes 25 kg of fumed silica and 10 kg of light calcium carbonate.

[0044] The titanium complex specifically includes 0.8 kg of a primary titanium complex and 1.2 kg of a secondary titanium complex.

[0045] The curing accelerator is specifically a combination of MOA-4, MOA-5 and MOA-9, wherein the mass ratio of MOA-4, MOA-5 and MOA-9 is 1:0.8:1.2, i.e. including 0.4 kg of MOA-4, 0.32 kg of MOA-5 and 0.48 kg of MOA-9.

[0046] A preparation method of a silicone weather-resistant adhesive, comprising the following steps: S1, after the base gum and the plasticizer are uniformly mixed and stirred, the reinforcing filler and the tetrasilanol phenyl POSS are added, and the stirring is continuously performed until they are uniformly dispersed to obtain a base gum; S2, the base gum obtained in S1 is heated to 110℃ and vacuum dehydrated for 5 min, and after it is cooled to room temperature, the silane coupling agent and the dealcoholization crosslinking agent are added, and the vacuum state is maintained and uniformly stirred to prepare a mixed gum; S3, the titanium complex and the curing accelerator are further added to the mixed gum obtained in S2, the vacuum state is maintained and uniformly stirred to prepare a target gum, and finally dry inert gas is introduced to balance the vacuum, and the target gum is extruded and stored in a sealed state under a dry inert atmosphere to obtain the silicone weather-resistant adhesive.

[0047]

Example 3

Example 1

[0048] In this example, the base gum specifically consists of an α,ω-dihydroxypolydimethylsiloxane having a viscosity of 20,000 mPa-s.

[0049] [Example 4] A silicone weather-resistant adhesive, which differs from [Example 1] in that the base gum is different.

[0050] In this example, the base gum specifically consists of an α,ω-dihydroxypolydimethylsiloxane having a viscosity of 80,000 mPa-s.

[0051] [Example 5] A silicone weather-resistant adhesive, which differs from [Example 1] in that the silanol phenyl POSS is different.

[0052] In this example, the silanol phenyl POSS is specifically tetrasilanol phenyl POSS.

[0053] [Example 6] A silicone weather-resistant adhesive, which differs from [Example 5] in that the plasticizer is different.

[0054] In this example, the plasticizer is specifically a combination of dimethyl silicone oil and long-chain alkyl-modified phenyl silicone oil, wherein the dimethyl silicone oil has a viscosity of 500 mPa-s, the long-chain alkyl-modified phenyl silicone oil is specifically prepared by [Preparation Example 1], and the mass ratio of the dimethyl silicone oil and the long-chain phenyl silicone oil is 9:1, i.e., 18 kg of dimethyl silicone oil and 2 kg of long-chain alkyl-modified phenyl silicone oil are included.

[0055] [Example 7] A silicone weather-resistant adhesive, which differs from [Example 6] in that the plasticizer is different.

[0056] In this example, the mass ratio of the dimethyl silicone oil and the long-chain phenyl silicone oil is 4:1, i.e., 16 kg of dimethyl silicone oil and 4 kg of long-chain alkyl-modified phenyl silicone oil are included.

[0057] [Example 8] A silicone weather-resistant adhesive, which differs from [Example 6] in that the plasticizer is different.

[0058] In this example, the mass ratio of the dimethyl silicone oil and the long-chain phenyl silicone oil is 1:1, i.e., 10 kg of dimethyl silicone oil and 10 kg of long-chain alkyl-modified phenyl silicone oil are included.

[0059] [Example 9] A silicone weather-resistant adhesive, which differs from [Example 7] in that the curing accelerator is different.

[0060] In this example, the curing accelerator specifically adopts a composition of MOA-4, MOA-5 and MOA-9, wherein the mass ratio of MOA-4, MOA-5 and MOA-9 is 1:0.5:1.5, i.e. including 0.3 kg of MOA-4, 0.15 kg of MOA-5 and 0.45 kg of MOA-9.

[0061] Example 10 A silicone weather-resistant adhesive, which is different from Example 7 in that the curing accelerator is different.

[0062] In this example, the curing accelerator specifically adopts a composition of MOA-4, MOA-5 and MOA-9, wherein the mass ratio of MOA-4, MOA-5 and MOA-9 is 1:0.5:2.1, i.e. including 0.25 kg of MOA-4, 0.125 kg of MOA-5 and 0.525 kg of MOA-9. Comparative Example

[0063] Comparative Example 1 A silicone weather-resistant adhesive, which is different from Example 1 in that no silanol phenyl POSS is added.

[0064] Comparative Example 2 A silicone weather-resistant adhesive, which is different from Example 1 in that no silanol phenyl POSS is added.

[0065] In this comparative example, triphenylsilanol is used to replace silanol phenyl POSS in equal amount.

[0066] Comparative Example 3 A silicone weather-resistant adhesive, which is different from Example 1 in that no curing accelerator is added. Performance test data

[0067] 1. Surface dry time: detected according to GB / T 13477.5 Building Sealant Test Methods Part 5: Determination of Surface Dry Time, tested according to the A method in the standard, the test temperature is 25℃, the relative humidity is 50%, and the surface dry time (min) of each example and comparative example is recorded, wherein the test interval is 2 min, and when the sample no longer adheres to the polyethylene strip, the current time is recorded (the recorded time should be a multiple of 2 min).

[0068] 2. Low-temperature curing speed: detected according to GB / T 32369-2005 Determination of Curing Degree of Sealant, tested by using method two wedge groove method, and tested in a low-temperature environment, the test temperature of the low-temperature environment is -10±2℃, and the thickness (mm) of the silicone weather-resistant adhesive after a certain time is recorded.

[0069] 3. Extreme temperature difference resistance: tested according to GB / T 13477.7 Test methods for building seals Part 7: Determination of low temperature flexibility, wherein the silicone sealant to be tested is completely cured at room temperature before testing, and the test conditions are treated according to the following temperature cycle for ten cycles: a) treated at 120±2℃ for 16h; b) treated at -60±3℃ for 8h, and after the end of the fifth cycle, it is taken out in the environment of (-60±3℃) and the detection is completed within 1-2s, observing and recording the cracking and adhesion damage.

[0070] 4. Mechanical properties and heat aging resistance: first tested according to GB / T 13477.8 Test methods for building seals Part 8: Determination of tensile adhesion properties, record the tensile strength (MPa) and elongation at break (%) of each example and the comparative example, then place the same sample in a 150℃ environment for 48h, take it out and let it cool naturally, then measure its tensile strength (MPa) and elongation at break (%) again, and calculate the retention rate of tensile strength and elongation at break.

[0071] Table 1 Partial performance test data of silicone weather-resistant adhesive

[0072] Table 2 Mechanical property data of silicone adhesive

[0073] According to the data in Table 1 and Table 2 combined with Example 1 and Comparative Examples 1-3, it can be seen that by introducing silanol phenyl POSS into the silicone weather-resistant adhesive, the heat aging resistance and low temperature resistance can be significantly improved, not only can ensure that the silicone weather-resistant adhesive can maintain high mechanical properties and adhesion strength for a long time in a high temperature environment, but also can have high low temperature flexibility after multiple extreme high-low temperature cycle changes, which can effectively prevent the rapid aging or adhesion failure of the silicone weather-resistant adhesive due to large temperature difference changes. In addition, when the curing accelerator composed of fatty alcohol polyoxyethylene ether is introduced into the system at the same time, the problem of slow curing and slow curing speed of the silicone adhesive after the introduction of silanol phenyl POSS can be effectively solved, which is beneficial to improve the curing efficiency of the silicone weather-resistant adhesive containing silanol phenyl POSS and realize normal curing.

[0074] From the data in Tables 1 and 2 in combination with Examples 1 and 3-4, it can be seen that by adjusting the viscosity of the base gum, using α, ω-dihydroxy polydimethylsiloxane with a viscosity of 20,000 mPa·s and α, ω-dihydroxy polydimethylsiloxane with a viscosity of 80,000 mPa·s mixed in a proper ratio, compared with using a single viscosity, the silicone weather-resistant adhesive prepared from the mixed base gum has better curing efficiency, mechanical strength and bonding performance. Among them, from Examples 3 and 4, it can be seen that when directly using α, ω-dihydroxy polydimethylsiloxane with low viscosity as the base gum, the silicone weather-resistant adhesive has higher curing speed and tensile strength after complete curing, but has lower elongation at break. On the contrary, when directly using α, ω-dihydroxy polydimethylsiloxane with high viscosity as the base gum, the silicone weather-resistant adhesive also has higher elongation at break, but has low tensile strength and slow surface drying time. Therefore, using a mixed base gum is more conducive to preparing silicone weather-resistant adhesive with higher comprehensive performance.

[0075] From the data in Tables 1 and 2 in combination with Examples 1 and 5, it can be seen that the introduction of tetra-silanol phenyl POSS in the silicone weather-resistant adhesive has a small amount of improvement in the surface drying speed and the overall curing efficiency, and the tensile strength and heat aging resistance are also improved to a certain extent, compared with the introduction of tri-silanol phenyl POSS. This may be because the tetra-silanol phenyl POSS contains four silanol groups, which has higher reactivity than the tri-silanol phenyl POSS, and the cross-linked network formed by the silicone phenyl POSS has higher density and more rigid sites, which is conducive to improving the mechanical properties of the silicone weather-resistant adhesive after curing, thereby showing the improvement in the tensile strength and heat aging resistance.

[0076] From the data in Tables 1 and 2 in combination with Examples 5-8, it can be seen that when the long-chain alkyl-modified phenyl silicone oil is used to replace part of the dimethyl silicone oil in the plasticizer, the overall heat aging resistance and temperature difference resistance can be further improved, but as the content of the long-chain alkyl-modified phenyl silicone oil increases, the performance improvement effect gradually weakens. When the ratio of the long-chain alkyl-modified phenyl silicone oil to the dimethyl silicone oil is 1:1, the overall curing efficiency of the silicone weather-resistant adhesive is obviously weak, which is not conducive to the full curing in a low-temperature environment.

[0077] From the data in Tables 1 and 2 in combination with Examples 7 and 9-10, it can be seen that when the curing accelerator is a composition of MOA-4, MOA-5 and MOA-9 mixed at a mass ratio of 1:0.5:(1-1.5), the surface dry time and overall curing efficiency of the silicone weatherproof adhesive can be significantly improved, and the mechanical properties are also slightly improved. However, as the content of MOA-9 is further increased, the overall curing efficiency of the silicone weatherproof adhesive is significantly reduced, and the elongation at break is also decreased, which is probably because as the content of MOA-9 is further increased, the overall hydrophilicity and wettability of the silicone weatherproof adhesive are stronger, resulting in a shorter surface curing time, which directly hinders the moisture in the air from entering the deep layer, and thus the overall, especially the deep layer, curing efficiency is lower.

[0078] The specific embodiments are merely illustrative of the present application, and are not intended to limit the present application. Those skilled in the art can make modifications to the specific embodiments according to the present specification without creative contribution, and the modifications are within the scope of the present application.

Claims

1. A silicone weatherable adhesive, characterized by: The silicone weather-resistant adhesive comprises the following raw materials by weight: Base rubber: 100 parts; Plasticizer: 15-25 parts; Silanol phenyl POSS: 0.5-1 part; De-alcohol cross-linking agent: 8-12 parts; Reinforcing filler: 35-50 parts; Titanium complex: 1.6-2 parts; Silane coupling agent: 1.5-1.8 parts; Curing accelerator: 0.9-1.2 parts; The base rubber is α, ω-dihydroxy polydimethylsiloxane, the plasticizer comprises dimethyl silicone oil, and the curing accelerator is C12-C14 fatty alcohol polyoxyethylene ether.

2. The silicone weatherable adhesive of claim 1, wherein: The viscosity of the base rubber is 20000-80000 mPa·s, and the viscosity of the dimethyl silicone oil is 350-500 mPa·s.

3. The silicone weatherable adhesive of claim 1, wherein: The silanol phenyl POSS is one of trisilanol phenyl POSS or tetrasilanol phenyl POSS.

4. The silicone weatherable adhesive of claim 1, wherein: The plasticizer further comprises long-chain alkyl modified phenyl silicone oil, and the mass ratio of the dimethyl silicone oil to the long-chain alkyl modified phenyl silicone oil is (4-9):1, wherein the long-chain alkyl modified phenyl silicone oil is prepared by reacting long-chain α-olefin with phenyl hydrogen-containing silicone oil.

5. The silicone weatherable adhesive of claim 1, wherein: The curing accelerator is specifically a combination of MOA-4, MOA-5 and MOA-9, and the mass ratio of the MOA-4, the MOA-5 and the MOA-9 is 1:0.5:(1-1.5).

6. The silicone weatherable adhesive of claim 1, wherein: The de-alcohol cross-linking agent is at least one of methyl trimethoxysilane or ethyl trimethoxysilane.

7. The silicone weatherable adhesive of claim 1, wherein: The reinforcing filler is a combination of fumed silica and light calcium carbonate, and the mass ratio of the fumed silica to the light calcium carbonate is (5-7):(2-3).

8. The silicone weatherable adhesive of claim 1, wherein: The titanium complex is a combination of primary titanium complex and secondary titanium complex, and the mass ratio of the primary titanium complex to the secondary titanium complex is 1:(1-1.5).

9. The silicone weatherable adhesive of claim 1, wherein: The silane cross-linking agent is silane coupling agent KH-550.

10. A method for preparing a silicone weatherable adhesive for use in the preparation of a silicone weatherable adhesive as claimed in any one of claims 1 to 9, characterised in that, The silicone weather-resistant adhesive comprises the following steps: S1, uniformly mixing and stirring the base rubber and the plasticizer, then adding the reinforcing filler and the silanol phenyl POSS, continuously stirring and uniformly dispersing to obtain the base rubber; S2, heating the base rubber obtained in S1 to 105-110 DEG C and performing vacuum dehydration for 5-10 min, cooling to room temperature, then adding the silane coupling agent and the de-alcohol cross-linking agent, uniformly stirring under vacuum to obtain a mixed rubber; S3, adding the titanium complex and the curing accelerator to the mixed rubber obtained in S2, uniformly stirring under vacuum to obtain a target rubber, finally balancing the vacuum by introducing dry inert gas, extruding the target rubber under a dry inert atmosphere by using a press, and sealing and storing to obtain the silicone weather-resistant adhesive.

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