High-strength alkoxyl terminated 107 gum and method of making and dealcoholized silicone rubber and method of making

Abstract

The application relates to the field of dealcoholized silicone rubber, in particular to a high-strength alkoxyl-terminated 107 glue and a preparation method and dealcoholized silicone rubber and a preparation method. The high-strength alkoxyl-terminated 107 glue comprises: end-side vinyl silicone oil, a silicon ethylene silicone oligomer, a catalyst and A-171 vinyl trimethoxysilane. The high-strength alkoxyl-terminated 107 glue is matched with a silicon-nitrogen heterocyclopentane compound to prepare dealcoholized silicone rubber, so that the dealcoholized silicone rubber exhibits excellent storage stability and can maintain good performance without attenuation even after long-time storage. Meanwhile, the bonding capacity of the dealcoholized silicone rubber to various substrates is obviously improved, and the dealcoholized silicone rubber is especially suitable for application fields such as high-precision and high-demand electronics, and reliable connection of products in different environments is ensured.

Description

Technical Field

[0001] The present application relates to the field of dealcoholized silicone rubber, and more specifically, to a high-strength alkoxy-terminated 107 rubber and a preparation method thereof, and a dealcoholized silicone rubber and a preparation method thereof. Background Art

[0002] In the current chemical materials sector, room temperature vulcanized silicone rubber (RTV silicone rubber), as an important polymer material, is widely used in industries such as construction, electronics, and automotive due to its unique physical and chemical properties, such as good weather resistance, excellent insulation, and good adhesion to a variety of substrates. Among them, 107 rubber (α,ω-dihydroxypolydimethylsiloxane), the base rubber for most RTV silicone rubber, holds a key position due to its non-flammability, affordable price, and ease of use.

[0003] Most existing 107 glues are deacidified, dealcoholized, or dealkontoximate types. Dealcoholized 107 glue is neutral, clean, non-toxic, non-corrosive, and relatively low-cost, with excellent bonding properties to materials such as glass and metal. Dealcoholized room-temperature vulcanized silicone rubber prepared using dealcoholized 107 glue is environmentally friendly due to the release of small molecules of methanol or ethanol. It is non-corrosive to metals and lacks a pungent odor, making it widely used in industries such as electronics, construction, and automotive. However, in the practical application of 107 glue and its derived room-temperature vulcanized silicone rubbers, particularly in the preparation and use of dealcoholized silicone rubber, a series of challenges remain that need to be addressed.

[0004] First, during the preparation of traditional dealcoholized silicone rubber, titanate catalysts are often used to promote the crosslinking reaction. However, these catalysts can cause a sharp increase in the viscosity of the rubber compound, resulting in a viscosity peak. This not only increases production difficulty but can also damage production equipment. Furthermore, the use of titanate catalysts can lead to poor storage stability, making the product prone to premature curing or deterioration, thus affecting its performance.

[0005] To address these issues, researchers have attempted to treat 107 silicone rubber with alkoxy groups to improve viscosity control and storage stability. However, commercially available alkoxy-terminated 107 rubbers lack sufficient reactivity and strength to fully meet market demand. Therefore, developing an alkoxy-terminated 107 rubber that effectively controls peak viscosity, improves storage stability, and combines high reactivity and strength has become a research hotspot.

[0006] On the other hand, during the storage of dealcoholized silicone rubber, the residual water in the rubber reacts with crosslinkers (such as methyltrimethoxysilane) to generate free methanol. This not only reduces the storage stability of the silicone rubber and shortens its effective storage period (usually only 3-6 months), but also poses potential hazards to the environment and human health. Although studies have attempted to address this issue by adding stabilizers (such as β-diketone compounds), these stabilizers are unable to simultaneously remove water, capture free alcohol, and enhance adhesion to the contacting substrate, which is a technical challenge in the industry.

[0007] In summary, there are problems in the preparation, storage and use of dealcoholized room temperature vulcanized silicone rubber in the prior art, and an innovative solution is urgently needed. Summary of the Invention

[0008] To address these issues, this application provides a high-strength alkoxy-terminated 107 silicone rubber and its preparation method, as well as a dealcoholized silicone rubber and its preparation method. By optimizing the alkoxy-terminated 107 silicone rubber process and combining it with a highly effective multifunctional stabilizer, these methods effectively address issues such as viscosity peaks, poor storage stability, low reactivity and strength, and the formation of free methanol. This provides more reliable technical support for the preparation and application of room-temperature vulcanized silicone rubber.

[0009] In the first aspect, the present application provides a high-strength alkoxy-terminated 107 glue, which adopts the following technical solution:

[0010] A high-strength alkoxy-terminated 107 glue comprising the following components:

[0011] 100 parts by mass of vinyl-terminated silicone oil;

[0012] 3-10 parts by mass of silylethylenesiloxane oligomer;

[0013] 1-10 ppm platinum catalyst;

[0014] 0.06-0.25 parts by mass of A-171 vinyltrimethoxysilane;

[0015] The ratio of the vinyl content of the vinyl-terminated silicone oil to the hydrogen content of the silylethylenesiloxane oligomer is 1:(1-1.15);

[0016] The ratio of the vinyl content of A-171 vinyltrimethoxysilane to the hydrogen content of the silylethylenesiloxane oligomer is (1-1.25):1.

[0017] The structural formula of silylethylenesiloxane oligomer is as follows:

[0018]

[0019] The structural formula of high-strength alkoxy-terminated 107 glue is as follows (n and m are integers, and m is not 0):

[0020]

[0021] Where m≠0

[0022]

[0023] By employing the aforementioned technical solution, alkoxy-terminated 107 rubber was prepared via hydrosilylation using vinyl-terminated silicone oil and silylethylenesiloxane oligomers as raw materials. This innovation not only greatly enhances the reaction activity, making the reaction process faster and more efficient, but also significantly improves the strength of the final product, meeting the stringent mechanical property requirements of high-performance materials. Furthermore, this improvement effectively addresses the poor storage stability issues faced by traditional dealcoholized silicone rubber during its preparation, extending the product's shelf life, reducing storage costs, and enhancing its market competitiveness.

[0024] In terms of raw material selection, this application abandons the use of traditional hydrogen-containing silanes (such as hydrogen-containing trimethoxysilane or hydrogen-containing methyldimethoxysilane) and instead uses silylene siloxane oligomers, which are relatively non-toxic and harmless, have a high flash point (flash point greater than 60°C), good safety and stability, and a mild and controllable reaction.

[0025] In order to further improve the storage stability, this application makes the hydrogen content of the silylethylenesiloxane oligomer slightly higher than the vinyl content of the end-side vinyl silicone oil, and then introduces an excess of A-171 vinyltrimethoxysilane into the reaction system. This step not only ensures the thoroughness of the silanization reaction and avoids the adverse effects of unreacted hydrogen bonds on product quality, but also plays the dual role of A-171 vinyltrimethoxysilane as a stabilizing dehumidifier and cross-linking agent. A-171 can effectively remove moisture from the system and prevent colloid degradation or performance degradation caused by moisture; at the same time, its cross-linking effect enhances the cohesion and structural stability of the colloid, so that the alkoxy-terminated 107 glue can maintain excellent performance during storage and is not prone to aging or deterioration. This innovative design greatly improves the storage stability of the product and provides a more reliable and long-lasting user experience.

[0026] Preferably, the ratio of the vinyl content of the terminal vinyl silicone oil to the hydrogen content of the silanol oligomer is 1:(1.05-1.1);

[0027] The ratio of the vinyl content of A-171 vinyltrimethoxysilane to the hydrogen content of silylethylenesiloxane oligomer is (1.1-1.2):1.

[0028] By adopting the above technical scheme, the content of the vinyl group of the end-side vinyl silicone oil and the hydrogen content of the silicic ethylene silicone oligomer, the content of the vinyl group of the A-171 vinyl trimethoxysilane and the hydrogen content of the silicic ethylene silicone oligomer are further optimized, so that the silicon hydrogen addition reaction is complete, and the excess silicic ethylene silicone oligomer is reacted by the excess A-171 vinyl trimethoxysilane. The excess A-171 vinyl trimethoxysilane with a further limited amount not only has no effect on the 107 glue, but on the contrary, it has the dual functions of stabilizing the water removing agent and the crosslinking agent, which is beneficial to the subsequent preparation of the dealcoholized silicone rubber.

[0029] Preferably, the viscosity of the end-side vinyl silicone oil is 500 mPa.s-80000 mPa.s.

[0030] In a second aspect, the application provides a preparation method of high-strength alkyl-terminated 107 glue, which adopts the following technical scheme:

[0031] A preparation method of high-strength alkyl-terminated 107 glue, comprising the following steps:

[0032] Step 1: mixing the end-side vinyl silicone oil, the silicic ethylene silicone oligomer and the platinum catalyst, and reacting at 50-100℃ for 120-360 min to obtain a first reactant;

[0033] Step 2: reacting the first reactant with the A-171 vinyl trimethoxysilane at 50-100℃ for 60-120 min to obtain the high-strength alkyl-terminated 107 glue.

[0034] Preferably, the reaction temperature of the step 1 and the step 2 is 60℃.

[0035] In a third aspect, the application provides a dealcoholized silicone rubber.

[0036] A dealcoholized silicone rubber, according to mass fraction, comprising the following components: 60-70 parts of high-strength alkyl-terminated 107 glue, 1-6 parts of a silicic-nitrogenous-cyclopentane compound, 10-15 parts of hydrophobic fumed silica, 1-3 parts of a crosslinking agent, 0.1-0.5 parts of a coupling agent, 0.1-0.5 parts of a catalyst, and 5-10 parts of dimethyl silicone oil.

[0037] Preferably, the crosslinking agent comprises one or more of methyl trimethoxysilane and cyanoethyl trimethoxysilane.

[0038] Preferably, the coupling agent is glycidyl ether propyl trimethoxysilane (KH560).

[0039] Preferably, the catalyst is one of an organic titanium catalyst and an organic tin catalyst.

[0040] Preferably, the catalyst is an organotin catalyst, further preferably dibutyltin dilaurate.

[0041] The dealcoholized silicone rubber is a room temperature vulcanized silicone rubber with dealcoholized components.

[0042] The synergistic effect of the silicon-nitrogen heterocyclopentane compound and the high-strength alkoxyl-terminated 107 glue enables the silicone sealant to exhibit excellent storage stability and maintain good performance without attenuation even after long-term storage. Meanwhile, the adhesion to various substrates is significantly improved, which is particularly suitable for high-precision and high-demand applications such as electronics, ensuring reliable connection of products in different environments.

[0043] For the precision manufacturing industry such as electronics, the dealcoholized component room temperature vulcanized silicone rubber of the present application has stronger adhesion and smaller glue usage, directly reducing production costs and improving production efficiency. Meanwhile, the excellent comprehensive performance also reduces the frequency of later maintenance and replacement, further improving the overall economic benefits.

[0044] Moreover, the synergistic effect of the silicon-nitrogen heterocyclopentane compound and the high-strength alkoxyl-terminated 107 glue can effectively balance the effects of water removal and free alcohol capture, significantly enhancing the resistance of the dealcoholized component room temperature vulcanized silicone rubber to environmental factors, ensuring excellent performance and long-term stability of the final product.

[0045] Preferably, the silicon-nitrogen heterocyclopentane compound is synthesized by reacting hexamethyldisilazane with a diorganosiloxane oligomer terminated by aminoalkyl dialkoxysilyl groups at both ends of the molecular chain (amino-functionalized diorganosiloxane oligomer), and the synthesis path is as follows:

[0046]

[0047] By adopting the above technical solution, the 1-silicon-nitrogen heterocyclopentyl siloxane oligomer and the condensation product, i.e., the silicon-nitrogen heterocyclopentane compound, generated by reacting hexamethyldisilazane with the amino-functionalized diorganosiloxane oligomer with a specific structure through the above synthesis path is a high-efficiency stabilizer with strong alcohol removal and adhesion enhancement effects, effectively solving the problem of free alcohol generated during the curing process of traditional dealcoholized silicone rubber, and significantly enhancing the adhesion between the sealant and the substrate, ensuring the durability and reliability of the sealing effect.

[0048] The additive not only effectively removes the free alcohol generated during the curing process, but also effectively captures and removes trace amounts of water in the system, further improving the purity and curing quality of the silicone sealant. This property is crucial for improving the electrical insulation performance and long-term durability of the product.

[0049] Preferably, the synthesis of the silicon-aza-cyclopentane compound comprises the following steps:

[0050] Step a: mixing alpha, omega dihydroxyl polydimethylsiloxane and aminopropyl trimethoxysilane according to mass ratio (1.3-1.6):1, dropping a small amount of aqueous formic acid, and reacting at 55-65℃ for 0.5-1.5h to obtain an amino-functionalized diorganosiloxane oligomer;

[0051] Step b: mixing the amino-functionalized diorganosiloxane oligomer, hexamethyldisilazane, and trimethylchlorosilane, and reacting at 95-105℃ for 7-9h to obtain a silicon-aza-cyclopentane compound.

[0052] In a fourth aspect, the application provides a preparation method of dealcoholized silicone rubber.

[0053] A preparation method of dealcoholized silicone rubber comprises the following steps:

[0054] Step A: mixing high-strength alkoxyl-terminated 107 glue and dimethyl silicone oil at 30-50℃ under vacuum (-0.085-0.095Mpa) for 5-10min to obtain a first mixture;

[0055] Step B: mixing the first mixture with a crosslinking agent, a coupling agent, and a silicon-aza-cyclopentane compound under vacuum (-0.035-0.055Mpa) for 5-10min to obtain a second mixture;

[0056] Step C: mixing the second mixture with hydrophobic fumed silica under vacuum high-speed dispersion for 15-30min, and then high-speed dispersion for 5-10min while vacuum (-0.085-0.095Mpa) is applied to obtain a third mixture;

[0057] Step D: mixing the third mixture with a catalyst under vacuum (-0.085-0.095Mpa) for 5-10min to obtain dealcoholized silicone rubber.

[0058] In summary, the application has the following beneficial effects:

[0059] 1. The alkoxyl-terminated 107 glue is prepared by using end-side vinyl silicone oil and silicon ethylene siloxane oligomer as raw materials and by silicon hydrogen addition, the content of alkoxyl-terminated 107 can be adjusted according to demand, the reaction activity can be adjusted, and then the curing operation time and strength of alcohol type glue can be adjusted.

[0060] 2. In the preparation process, after the end-side vinyl silicone oil and the silicone ethylene siloxane oligomer are reacted, an excess of A-171 vinyl trimethoxysilane is added for continuous reaction to ensure complete hydrogen bond reaction of the system, and the A-171 is also a stable water removal agent and crosslinking agent, which improves the storage stability of the alkoxy-terminated 107 glue.

[0061] 3. The silicone ethylene siloxane oligomer is used as a raw material, and the silicone ethylene siloxane oligomer has no toxicity and harm, a high flash point (the flash point is greater than 60 DEG C), good safety, and good stability compared with hydrogen-containing silane (hydrogen-containing trimethoxysilane or hydrogen-containing methyl dimethoxysilane), and the reaction is mild and controllable.

[0062] 4. The silicon-nitrogen heterocyclopentane compound (1-silicon-nitrogen heterocyclopentyl siloxane oligomer and condensation product at both ends of the molecular chain) obtained by reacting hexamethyldisilazane and an amino-functional diorganosiloxane oligomer (diorganosiloxane oligomer terminated by aminoalkyl dialkoxysilyl at both ends of the molecular chain) is a high-efficiency stabilizer, which is used for preparing a dealcoholization type component room temperature curing silicone rubber sealant, and has the effects of water removal, free alcohol capture, and adhesion improvement, so that the prepared sealant has good storage stability and excellent bonding performance to a contact substrate. BRIEF DESCRIPTION OF DRAWINGS

[0063] Figure 1 is a structural formula of the silicone ethylene siloxane oligomer.

[0064] Figure 2 is a structural formula of the high-strength alkoxy-terminated 107 glue.

[0065] Figure 3 is a reaction process schematic diagram of step b. DETAILED DESCRIPTION

[0066] The application is further described in detail below in combination with the drawings and examples.

[0067] The raw materials used in the following examples and comparative examples are all commercially available products.

[0068] The end-side vinyl silicone oil has a viscosity of 500 mPa.s to 80000 mPa.s.

[0069] EXAMPLE

[0070] Example 1

[0071] A high-strength alkoxy-terminated 107 glue comprises 100 parts by mass of 19560cs end-side vinyl silicone oil with a vinyl content of 0.442%; 5 parts by mass of silicone ethylene siloxane oligomer with a hydrogen content of 0.36%; 5 ppm (content of total material) platinum catalyst; and 0.118 parts by mass of A-171 vinyl trimethoxysilane.

[0072] The ratio of the vinyl content of the end-vinyl silicone oil to the hydrogen content of the sila-ethylsiloxane oligomer is 1:1.1.

[0073] The ratio of the vinyl content of the A-171 vinyl trimethoxysilane to the hydrogen content of the sila-ethylsiloxane oligomer is 1.2:1.

[0074] The platinum catalyst is a Karstedt catalyst.

[0075] The structural formula of the sila-ethylsiloxane oligomer is shown in Figure 1 .

[0076] The application also provides a preparation method of the high-strength alkoxy-terminated 107 adhesive, comprising the following steps:

[0077] Step 1: mixing the end-vinyl silicone oil and the sila-ethylsiloxane oligomer, and then adding the platinum catalyst to react at 60°C for 240 min to obtain a first reactant.

[0078] Step 2: adding the A-171 vinyl trimethoxysilane into the first reactant to react at 60°C for 90 min. After the reaction is completed, cooling is performed to obtain the high-strength alkoxy-terminated 107 adhesive.

[0079] The structural formula of the high-strength alkoxy-terminated 107 adhesive is shown in Figure 2 .

[0080] The application also provides a dealcoholized silicone rubber, comprising the following components: 65.4 kg of the high-strength alkoxy-terminated 107 adhesive, 4 kg of a silicon-nitrogen heterocyclopentane compound, 8.5 kg of dimethyl silicone oil, 13 kg of hydrophobic fumed silica, 0.7 kg of cyanoethyl trimethoxysilane, 1 kg of methyl trimethoxysilane, 0.25 kg of glycidyl ether oxypropyl trimethoxysilane (KH560), and 0.24 kg of dibutyltin dilaurate.

[0081] The hydrophobic fumed silica in the example is purchased from Hui Fu in Yichang, and the model number is HB-620.

[0082] The synthesis of the silicon-nitrogen heterocyclopentane compound comprises the following steps:

[0083] Step a: mixing 40 g of α, ω dihydroxypolydimethylsiloxane and 27 g of aminopropyl trimethoxysilane, and then dropping a small amount (2 drops) of 80% mass fraction of formic acid aqueous solution to stir and react at 60°C for 1 h.

[0084] Then, under the condition of 2.66 kPa reduced pressure, distilling the reaction species at 120°C to remove unreacted components and methanol, a colorless transparent liquid is obtained, that is, the aminofunctional diorganosiloxane oligomer is obtained.

[0085] Step b: Mix the amino-functional diorganosiloxane oligomer, hexamethyldisilazane, and trimethylchlorosilane and slowly warm to 100°C. When the temperature is reached, trimethylmethoxysilane distills off along with a considerable amount of NH3. Continue to maintain the temperature and stir the reaction for 8 h.

[0086] Then distill off the volatile components at 100°C under reduced pressure of 2.66 kPa to obtain a light yellow liquid, which is the silicon-nitrogen-heterocyclopentane compound.

[0087] The reaction process of step b is shown schematically in Figure 3 .

[0088] The method for preparing the dealcoholized silicone rubber comprises the following steps:

[0089] Step A: Mix the high-strength alkoxy-terminated 107 glue and dimethyl silicone oil at 40°C under vacuum (-0.09 MPa) for 8 min to obtain a first mixture.

[0090] Step B: Mix the first mixture with the crosslinking agent, coupling agent, and silicon-nitrogen-heterocyclopentane compound under vacuum (-0.045 MPa) for 8 min to obtain a second mixture.

[0091] Step C: High-speed disperse the second mixture with the hydrophobic fumed silica under vacuum for 20 min, and then high-speed disperse under vacuum (-0.09 MPa) for 8 min to obtain a third mixture.

[0092] Step D: Mix the third mixture with the catalyst under vacuum (-0.09 MPa) for 8 min to obtain the dealcoholized silicone rubber.

[0093] Example 2

[0094] A high-strength alkoxy-terminated 107 glue, which is different from that of Example 1, comprises 100 parts by mass of 9820cs end-vinyl silicone oil with a vinyl content of 0.278%, 3 parts by mass of silicon-ethylsiloxane oligomer with a hydrogen content of 0.36%, 1 ppm (content of total material) platinum catalyst, and 0.065 parts by mass of A-171 vinyl trimethoxysilane.

[0095] The ratio of the vinyl content of the end-vinyl silicone oil to the hydrogen content of the silicon-ethylsiloxane oligomer is 1:1.05.

[0096] The ratio of the vinyl content of the A-171 vinyl trimethoxysilane to the hydrogen content of the silicon-ethylsiloxane oligomer is 1.1:1.

[0097] A method for preparing a high-strength alkoxyl-terminated 107 adhesive, which is different from that of Example 1, comprises the following steps:

[0098] Step 1: Mix the end-vinyl silicone oil and the silicone-ethylene silicone oligomer, and then add the platinum catalyst to react at 50°C for 360 min to obtain a first reactant.

[0099] Step 2: Add A-171 vinyl trimethoxysilane to the first reactant to react at 50°C for 120 min. After the reaction is completed, cool down to obtain the high-strength alkoxyl-terminated 107 adhesive.

[0100] A dealcoholized silicone rubber, which is different from that of Example 1, comprises the following steps:

[0101] The dealcoholized silicone rubber comprises the following components: 60 kg of high-strength alkoxyl-terminated 107 adhesive, 1 kg of a silicone-nitrogen heterocyclopentane compound, 5 kg of dimethyl silicone oil, 10 kg of hydrophobic fumed white carbon black, 0.4 kg of cyanoethyl trimethoxysilane, 0.6 kg of methyl trimethoxysilane, 0.1 kg of glycidyl ether oxypropyl trimethoxysilane (KH560), and 0.1 kg of dibutyltin dilaurate.

[0102] The synthesis of the silicone-nitrogen heterocyclopentane compound comprises the following steps:

[0103] Step a: Mix 35.1 g of α,ω-dihydroxypolydimethylsiloxane with 27 g of aminopropyl trimethoxysilane, drop a small amount (2 drops) of 80% mass fraction formic acid aqueous solution, and stir to react at 55°C for 1.5 h.

[0104] Then, distill the unreacted components and methanol from the reaction at 120°C under a reduced pressure of 2.66 kPa to obtain a colorless transparent liquid, i.e., the amino-functionalized diorganosiloxane oligomer.

[0105] Step b: Mix the amino-functionalized diorganosiloxane oligomer, hexamethyldisilazane, and trimethylchlorosilane, and slowly heat to 95°C. When the temperature reaches, trimethylmethoxysilane is distilled out, accompanied by a considerable amount of NH3. Continue to maintain the temperature and stir to react for 9 h.

[0106] Then, distill the volatile components at 100°C under a reduced pressure of 2.66 kPa to obtain a light yellow liquid, i.e., the silicone-nitrogen heterocyclopentane compound.

[0107] A method for preparing a dealcoholized silicone rubber, which is different from that of Example 1, comprises the following steps:

[0108] Step A: High strength alkoxy terminated 107 glue was mixed with dimethyl silicone oil at 30°C under vacuum (-0.095 Mpa) for 10 min to obtain a first mixture.

[0109] Step B: The first mixture was mixed with crosslinker, coupling agent and silicon-nitrogen heterocyclopentane compound under vacuum (-0.055 Mpa) for 5 min to obtain a second mixture.

[0110] Step C: The second mixture was high speed dispersed with hydrophobic fumed silica under vacuum for 20 min, and then high speed dispersed under vacuum (-0.095 Mpa) for 5 min to obtain a third mixture.

[0111] Step D: The third mixture was mixed with catalyst under vacuum (-0.095 Mpa) for 5 min to obtain a dealcoholized silicone rubber.

[0112] Example 3

[0113] A high strength alkoxy terminated 107 glue, which is different from example 1, comprises 100 parts by mass of 1430cs end vinyl silicone oil, vinyl content is 0.845%, 10 parts by mass of silicon ethylene siloxane oligomer, hydrogen content is 0.36%, 10 ppm (content of total material) platinum catalyst, 0.247 parts by mass of A-171 vinyl trimethoxysilane.

[0114] The ratio of the vinyl content of the end vinyl silicone oil to the hydrogen content of the silicon ethylene siloxane oligomer is 1:1.15.

[0115] The ratio of the vinyl content of the A-171 vinyl trimethoxysilane to the hydrogen content of the silicon ethylene siloxane oligomer is 1.25:1.

[0116] A method for preparing a high strength alkoxy terminated 107 glue, which is different from example 1, comprises the following steps:

[0117] Step 1: The end vinyl silicone oil and the silicon ethylene siloxane oligomer are mixed, and then the platinum catalyst is added to react at 100°C for 120 min to obtain a first reactant.

[0118] Step 2: A-171 vinyl trimethoxysilane is added to the first reactant to react at 100°C for 60 min. After the reaction is completed, cooling is performed to obtain a high strength alkoxy terminated 107 glue.

[0119] A dealcoholized silicone rubber, which is different from example 1, comprises:

[0120] The dealcoholized silicone rubber includes the following components: 70kg high-strength alkoxy-terminated 107 glue, 6kg silicon-aza-cyclopentane compound, 10kg dimethyl silicone oil, 15kg hydrophobic fumed silica, 1.2kg cyanoethyltrimethoxysilane, 1.8kg methyltrimethoxysilane, 0.5kg glycidyloxypropyltrimethoxysilane (KH560), and 0.5kg dibutyltin dineodecanoate.

[0121] The synthesis of silicon-aza-cyclopentane compounds comprises the following steps:

[0122] Step a: 43.2 g of α,ω dihydroxy polydimethylsiloxane was mixed with 27 g of aminopropyltrimethoxysilane, and a small amount (2 drops) of 80% by mass formic acid aqueous solution was added, and the mixture was stirred and reacted at 65° C. for 0.5 h.

[0123] Then, under a reduced pressure of 2.66 kPa, unreacted components of the reaction species and methanol were distilled off at 120° C. to obtain a colorless transparent liquid, namely, an amino-functionalized diorganosiloxane oligomer.

[0124] Step b: Combine the amino-functionalized diorganosiloxane oligomer, hexamethyldisilazane, and trimethylchlorosilane and slowly raise the temperature to 105°C. At this temperature, trimethylmethoxysilane will distill off, accompanied by a considerable amount of NH3. Maintain the temperature and stir the reaction for 7 hours.

[0125] Then, the volatile components were distilled at 100° C. and 2.66 kPa under reduced pressure to obtain a light yellow liquid, namely, a silicon-aza-cyclopentane compound.

[0126] The method for preparing dealcoholized silicone rubber is different from that of Example 1 in that it comprises the following steps:

[0127] Step A: High-strength alkoxy-terminated 107 glue and dimethyl silicone oil were stirred and mixed at 50° C. under vacuum (−0.085 MPa) for 5 minutes to obtain a first mixture.

[0128] Step B: The first mixture was mixed with a cross-linking agent, a coupling agent and a silicon-aza-cyclopentane compound under vacuum (-0.035 MPa) for 10 minutes to obtain a second mixture.

[0129] Step C: The second mixture and hydrophobic fumed silica are dispersed at high speed in vacuum for 20 minutes, and then dispersed at high speed for 10 minutes while evacuating (-0.085 MPa) to obtain a third mixture.

[0130] Step D: The third mixture and the catalyst were mixed under vacuum (-0.085 MPa) for 10 min to obtain dealcoholized silicone rubber.

[0131] Comparative Example

[0132] Comparative Example 1

[0133] A high-strength alkoxy-terminated 107 adhesive, which differs from Example 1 in that the ratio of the vinyl content of the end-vinyl silicone oil to the hydrogen content of the silicone-ethylsiloxane oligomer is 1:0.5.

[0134] That is, 100 parts by mass of an end-vinyl silicone oil, 19560 cs, having a vinyl content of 0.442%; and 2.27 parts by mass of a silicone-ethylsiloxane oligomer having a hydrogen content of 0.36%.

[0135] This high-strength alkoxy-terminated 107 adhesive is used in the production of a dealcoholized silicone rubber.

[0136] Other than this, the production method of the high-strength alkoxy-terminated 107 adhesive, the raw material composition of the dealcoholized silicone rubber, and the production method of the dealcoholized silicone rubber are the same as in Example 1, and are not described here.

[0137] Comparative Example 2

[0138] A high-strength alkoxy-terminated 107 adhesive, which differs from Example 1 in that the ratio of the vinyl content of the end-vinyl silicone oil to the hydrogen content of the silicone-ethylsiloxane oligomer is 1:2.

[0139] That is, 100 parts by mass of an end-vinyl silicone oil, 19560 cs, having a vinyl content of 0.442%; and 9.09 parts by mass of a silicone-ethylsiloxane oligomer having a hydrogen content of 0.36%.

[0140] This high-strength alkoxy-terminated 107 adhesive is used in the production of a dealcoholized silicone rubber.

[0141] Other than this, the production method of the high-strength alkoxy-terminated 107 adhesive, the raw material composition of the dealcoholized silicone rubber, and the production method of the dealcoholized silicone rubber are the same as in Example 1, and are not described here.

[0142] Comparative Example 3

[0143] A dealcoholized silicone rubber, which differs from Example 1 in that the high-strength alkoxy-terminated 107 adhesive is replaced with a commercially available end-terminated 107 adhesive (addition type) of 20000 cs.

[0144] Other than this, the raw material composition of the dealcoholized silicone rubber, and the production method of the dealcoholized silicone rubber are the same as in Example 1, and are not described here.

[0145] Comparative Example 4

[0146] A dealcoholized silicone rubber, which differs from Example 1 in that the silicone-nitrogen heterocyclopentane compound is replaced with acetylacetone.

[0147] In addition, the raw material composition of the dealcoholized silicone rubber, the preparation method of the dealcoholized silicone rubber is the same as that of Example 1, which is not described here.

[0148] Comparative Example 5

[0149] A dealcoholized silicone rubber, which is different from Example 1 in that the high-strength alkoxyl-terminated 107 glue is replaced with a commercially available 20000cs terminated 107 glue (addition type), and the silicon-nitrogen heterocyclopentane compound is replaced with acetylacetone.

[0150] In addition, the raw material composition of the dealcoholized silicone rubber, the preparation method of the dealcoholized silicone rubber is the same as that of Example 1, which is not described here.

[0151] Performance detection test

[0152] 1. Adhesion strength: The dealcoholized silicone rubber of Examples 1-3 and Comparative Examples 1-5 was detected according to GB / T 2791-1995 "Adhesive T-peel strength test method flexible material on flexible material", and the results were recorded in Table 1.

[0153] Table 1

[0154]

[0155] 2. Storage stability:

[0156] The detection object is the dealcoholized silicone rubber of Examples 1-3 and Comparative Examples 1-5.

[0157] The dealcoholized silicone rubber was detected according to GB / T 528-2009 "Determination of tensile stress-strain properties of vulcanized rubber or thermoplastic rubber", and the tensile strength and elongation were recorded in Table 2.

[0158] The smaller the difference between the tensile strength and elongation of the dealcoholized silicone rubber measured at 70°C for 7d and 14d and the initial measured data of the dealcoholized silicone rubber, the higher the storage stability.

[0159] Table 2

[0160]

[0161]

[0162] According to the detection data in Table 2, the dealcoholized silicone rubber of Examples 1-3 has a very small difference after being stored at 70°C for 7d and 14d compared with the initial measured data, indicating excellent storage stability.

[0163] The tensile strength of Examples 1-3 is higher than that of Comparative Examples 1, 3 and 5. Although the dealcoholized silicone rubber of Comparative Examples 2 and 4 has higher tensile strength than that of Example 1 at the initial stage, the performance decreases rapidly after storage at 70℃ for 7d and 14d, and is not as stable as that of Example 1.

[0164] For Comparative Example 2, the silicon ethylene siloxane oligomer is in excess, so that the high-strength alkoxy-terminated 107 glue generated has a large amount of short-chain structure, low viscosity and excessively high activity, which directly leads to poor storage stability of the prepared dealcoholized silicone rubber.

[0165] The dealcoholized silicone rubber of Comparative Examples 1 and 3 has a tensile strength that is not high at the initial stage, and the adhesion strength to various substrates is not high, which is difficult to meet the actual production requirements, although the data measured at the initial stage and after storage at 70℃ for 7d and 14d are not much different.

[0166] For Comparative Example 1, the end-side vinyl silicone oil does not react sufficiently with the silicon ethylene siloxane oligomer, which affects the performance of the high-strength alkoxy-terminated 107 glue, and leads to low mechanical properties and adhesion strength of the prepared dealcoholized silicone rubber.

[0167] As can be seen from Table 2, the strength and storage stability of the dealcoholized silicone rubber of Comparative Examples 4 and 5 have a significant gap with those of Example 1. This shows that the use of silicon-nitrogen heterocyclopentane compounds can indeed play a good role in water removal, free alcohol capture and adhesion to the contacted substrate, and has a good cooperation effect with the high-strength alkoxy-terminated 107 glue.

[0168] 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 embodiments without creative contribution after reading the present specification, and the modifications are within the scope of the present application.

Claims

1. Dealcoholized silicone rubber, characterized in that: The composition comprises the following components in parts by mass: 60-70 parts of high-strength alkoxy-terminated 107 glue, 1-6 parts of silicon-aza-cyclopentane compound, 10-15 parts of hydrophobic fumed silica, 1-3 parts of a crosslinking agent, 0.1-0.5 parts of a coupling agent, 0.1-0.5 parts of a catalyst, and 5-10 parts of dimethyl silicone oil; wherein: The high-strength alkoxy-terminated 107 glue includes the following components: 100 parts by mass of vinyl-terminated silicone oil; 3-10 parts by mass of silylethylenesiloxane oligomer; 1-10 ppm platinum catalyst; 0.06-0.25 parts by mass of A-171 vinyltrimethoxysilane; The ratio of the vinyl content of the vinyl-terminated silicone oil to the hydrogen content of the silylethylenesiloxane oligomer is 1:(1-1.15); The ratio of the vinyl content of A-171 vinyltrimethoxysilane to the hydrogen content of silylethylenesiloxane oligomer is (1-1.25):1; The synthesis of the silicon-aza-cyclopentane compound comprises the following steps: Step a: Mix α,ω dihydroxy polydimethylsiloxane and aminopropyltrimethoxysilane in a mass ratio of (1.3-1.6):1, add a small amount of formic acid aqueous solution, and react at 55-65°C for 0.5-1.5 hours to obtain an amino-functionalized diorganosiloxane oligomer; Step b: Mixing an amino-functionalized diorganosiloxane oligomer, hexamethyldisilazane, and trimethylchlorosilane, and reacting the mixture at 95-105° C. for 7-9 hours to obtain a silicon-aza-cyclopentane compound.

2. The dealcoholized silicone rubber according to claim 1, wherein: The ratio of the vinyl content of the terminal vinyl silicone oil to the hydrogen content of the silanol ethylene siloxane oligomer is 1:(1.05-1.1).

3. The dealcoholized silicone rubber according to claim 1, wherein: The ratio of the vinyl content of the A-171 vinyltrimethoxysilane to the hydrogen content of the silylethylenesiloxane oligomer is (1.1-1.2):

1.

4. The dealcoholized silicone rubber according to claim 1, wherein: The viscosity of the end-side vinyl silicone oil is 500mPa.s-80000mPa.s.

5. The dealcoholized silicone rubber according to claim 1, wherein: The preparation method of the high-strength alkoxy-terminated 107 glue comprises the following steps: Step 1: Mixing end-vinyl silicone oil, silylethylenesiloxane oligomer, and platinum catalyst, and reacting at 50-100° C. for 120-360 minutes to obtain a first reactant; Step 2: react the first reactant with A-171 vinyltrimethoxysilane at 50-100°C for 60-120 min to obtain high-strength alkoxy-terminated 107 glue.

6. The dealcoholized silicone rubber according to claim 5, wherein: The reaction temperature of step 1 and step 2 is 60°C.

7. The dealcoholized silicone rubber according to claim 1, wherein: The crosslinking agent includes a mixture of one or more of methyltrimethoxysilane and cyanoethyltrimethoxysilane.

8. The method for preparing the dealcoholized silicone rubber according to any one of claims 1 to 7, wherein: The following steps are involved: Step A: High-strength alkoxy-terminated 107 glue and dimethyl silicone oil were mixed at 30-50° C. under vacuum stirring for 5-10 minutes to obtain a first mixture; Step B: mixing the first mixture with a crosslinking agent, a coupling agent, and a silicon-aza-cyclopentane compound under vacuum for 5-10 minutes to obtain a second mixture; Step C: vacuum-dispersing the second mixture and hydrophobic fumed silica for 15-30 minutes at high speed, and then vacuum-dispersing the mixture for 5-10 minutes at high speed to obtain a third mixture; Step D: mixing the third mixture with the catalyst under vacuum for 5-10 minutes to obtain dealcoholized silicone rubber.

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