High temperature resistant low peel force silicone pressure sensitive adhesive and preparation method thereof

Abstract

The application relates to the field of high polymer materials, and discloses a high-temperature-resistant low-peeling-force organic silicon pressure-sensitive adhesive and a preparation method thereof. The organic silicon pressure-sensitive adhesive comprises: a methylene component: vinyl-terminated silicone oil, vinyl methyl MQ resin, (bisvinyl dimethyl) phenyl isomeromeric silsesquioxane xylene mixed solution and Koster catalyst; and an ethylene component: hydrogen-terminated silicone oil, methyl hydrogen-containing MQ resin, (bis-methyl dihydrogen) phenyl isomeromeric silsesquioxane xylene mixed solution and a reaction rate regulator. The (bisvinyl dimethyl) phenyl isomeromeric silsesquioxane and the (bis-methyl dihydrogen) phenyl isomeromeric silsesquioxane containing rich phenyl groups are added to the organic silicon pressure-sensitive adhesive through silicon hydrogen addition, the viscosity of a reaction system can be obviously reduced, a large amount of organic solvent is not needed for dilution and viscosity reduction, the method is more environmentally friendly, the peeling force of the organic silicon pressure-sensitive adhesive can be obviously reduced, and the heat resistance of the organic silicon pressure-sensitive adhesive can be improved.

Description

Technical Field

[0001] This invention relates to the field of polymer materials, and more particularly to a high-temperature resistant, low-peel-force silicone pressure-sensitive adhesive and its preparation method. Background Technology

[0002] Silicone pressure-sensitive adhesives possess excellent shear strength, peel strength, cohesive strength, and adhesion. They exhibit good adhesion to both high-energy and low-energy surface materials, and also show good adhesion to untreated, difficult-to-bond materials. Furthermore, silicone pressure-sensitive adhesives also possess high and low temperature resistance (allowing for long-term use within a temperature range of -70 to 280°C), good chemical resistance, and electrical properties.

[0003] Over the past two decades, with the upgrading of products such as mobile phones, automobiles, televisions, and e-readers, the industry of protective films that provide protection or isolation has also developed rapidly. Because existing silicone polymers generally have high viscosity, when silicone pressure-sensitive adhesive products are applied in these fields, large amounts of organic solvents are needed to dilute them to a suitable viscosity range before use. This places enormous pressure on environmental protection and has increasingly attracted attention.

[0004] Furthermore, in certain applications, silicone pressure-sensitive adhesives with stable low peel strength suffer from insufficient temperature resistance or the tendency for low-molecular-weight silicone to leach and contaminate the surface of the adhered object. Therefore, developing an environmentally friendly, high-temperature resistant, and low-peel-strength silicone pressure-sensitive adhesive is of great significance. Summary of the Invention

[0005] To address the aforementioned technical problems, this invention provides a high-temperature resistant, low-peel-strength silicone pressure-sensitive adhesive and its preparation method. It also provides the application of (divinyldimethyl)phenyl isosilsesquioxane and (dimethyldihydro)phenyl isosilsesquioxane in reducing the viscosity of the silicone pressure-sensitive adhesive before curing or reducing its peel strength after curing. This invention adds phenyl-rich (divinyldimethyl)phenyl isosilsesquioxane and (dimethyldihydro)phenyl isosilsesquioxane to the silicone pressure-sensitive adhesive via hydrosilylation, which significantly reduces the viscosity of the reaction system without requiring large amounts of additional organic solvents for dilution, making it more environmentally friendly; it significantly reduces the peel strength of the cured silicone pressure-sensitive adhesive; and it improves the heat resistance of the silicone pressure-sensitive adhesive.

[0006] The specific technical solution of this invention is as follows:

[0007] In a first aspect, the present invention provides a high-temperature resistant, low-peel-stretch silicone pressure-sensitive adhesive, comprising the following raw materials in parts by weight:

[0008] Component A: 45-55 parts vinyl-terminated silicone oil, 20-30 parts vinyl methyl MQ resin, 20-30 parts (bisvinylbismethyl)phenyl isomersilsesquioxane xylene mixture, 0.1-0.3 parts caster catalyst.

[0009] Component B: 60-70 parts hydrogen-capped silicone oil, 8-12 parts methyl hydrogen-containing MQ resin, 20-30 parts (dimethyldihydro)phenyl isomeric silsesquioxane xylene mixture, and 0-0.3 parts reaction rate regulator. The silicone pressure-sensitive adhesive of this invention is obtained by curing Component A and Component B through a hydrogen silane reaction under heating, wherein:

[0010] In component A, vinyl-terminated silicone oil and hydrogen-containing end-terminated silicone oil serve as the base material for the silicone pressure-sensitive adhesive, i.e., the film-forming carrier material; vinyl MQ resin and methyl hydrogen-containing MQ resin serve as reinforcing fillers, improving the mechanical properties of the silicone pressure-sensitive adhesive; (bisvinylbismethyl)phenyl isosilsesquioxane and (bismethylbishydro)phenyl isosilsesquioxane are inorganic-organic hybrid materials. Besides improving the high-temperature resistance of the material, their more crucial role in this invention is to reduce the viscosity of the silicone pressure-sensitive adhesive before curing and to impart lower peel strength after curing. Specifically:

[0011] Regarding viscosity reduction: Since the molecules of (divinyldimethyl)phenyl isosilsesquioxane and (dimethyldihydro)phenyl isosilsesquioxane contain abundant phenyl groups, these large phenyl-containing compounds can reduce intermolecular forces after being grafted onto the polymer backbone during the curing process, thereby significantly reducing the viscosity of the reaction system. This reduces the amount of organic solvent used (conventional organosilicon materials generally have high viscosity, so a large amount of organic solvent must be used for dilution), making it more environmentally friendly.

[0012] Regarding reducing peel strength: (divinyldimethyl)phenyl isosilsesquioxane and (dimethyldihydro)phenyl isosilsesquioxane are characterized by symmetrical molecular structures and large volumes. Due to molecular motion, they remain in a stable state with the lowest energy for extended periods. This invention has found that this stable state can shield or reduce the forces exerted by surrounding molecules on the adhesive interface molecules, thus imparting lower peel strength to the silicone pressure-sensitive adhesive. Preferably, the synthetic route for the (divinyldimethyl)phenyl isosilsesquioxane xylene mixture is as follows:

[0013]

[0014] Preferably, the preparation method of the (divinyldimethyl)phenyl isomeric silsesquioxane xylene mixture includes:

[0015] a) Tetrahydrofuran, isopropanol, lithium hydroxide, cesium carbonate and water were added to a reaction vessel and stirred until homogeneous. Phenylacetyltrimethoxysilane was added dropwise. After the addition was complete, the mixture was heated to reflux and then cooled. Excess hydrochloric acid was slowly added dropwise. The mixture was filtered, washed and dried to obtain phenyltetrasilanol.

[0016] b): Phenyltetrasilyl alcohol, xylene, methylvinyldimethoxysilane and catalyst are mixed and reacted to prepare a (bisvinyldimethyl)phenylisomeric silsesquioxane xylene mixture.

[0017] Preferably, in a), the ratio of tetrahydrofuran, isopropanol, lithium hydroxide, cesium carbonate, water, phenyltrimethoxysilane, and hydrochloric acid is [ratio to be inserted here].

[0018] 140-160mL: 45-55mL: 0.06-0.10mol: 0.003-0.007mol: 3.4-3.8g: 0.14-0.18mol: 0.18-0.22mol.

[0019] Preferably, in b), the ratio of phenyltetrasilanol, xylene, and methylvinyldimethoxysilane is 0.008-0.012 mol: 45-55 g: 0.008-0.012 mol.

[0020] Preferably, in a) the heating and reflux reaction time is 20-30 h; the cooling is reduced to -3 to -7 °C; the washing is performed with methanol and acetonitrile at least once each; and the drying is performed at room temperature under reduced pressure for 20-30 h.

[0021] As a preferred embodiment, in b), the reaction is carried out at room temperature for 40-50 hours.

[0022] Preferably, the synthetic route for the (dimethyldihydro)phenyl isomeric silsesquioxane is as follows:

[0023]

[0024] Preferably, the preparation method of the (dimethyldihydro)phenyl isomeric silsesquioxane xylene mixture includes:

[0025] A): Tetrahydrofuran, isopropanol, lithium hydroxide, cesium carbonate and water were added to a reaction vessel and stirred until homogeneous. Phenylenetrimethoxysilane was added dropwise. After the addition was complete, the mixture was heated to reflux and then cooled. Excess hydrochloric acid was slowly added dropwise. The mixture was filtered, washed, and dried to obtain phenyltetrasilanol.

[0026] B): A mixture of phenyltetrasilyl alcohol, xylene, methyl hydrogen dimethoxysilane and catalyst was reacted to prepare a (dimethyl dihydro)phenyl isomeric silsesquioxane xylene mixture.

[0027] Preferably, in A), the ratio of tetrahydrofuran, isopropanol, lithium hydroxide, cesium carbonate, water, phenyltrimethoxysilane, and hydrochloric acid is [ratio to be inserted here].

[0028] 140-160mL: 45-55mL: 0.06-0.10mol: 0.003-0.007mol: 3.4-3.8g: 0.14-0.18mol: 0.18-0.22mol.

[0029] Preferably, in B), the ratio of the amount of phenyltetrasilanol, xylene and methylhydrodimethoxysilane is 0.008-0.012 mol: 45-55 g: 0.008-0.012 mol.

[0030] Preferably, in A): the heating and reflux reaction time is 20-30 h; the cooling is reduced to -3 to -7 °C; the washing is performed with methanol and acetonitrile at least once each; and the drying is performed at room temperature under reduced pressure for 20-30 h.

[0031] As a preferred embodiment, in B), the reaction is carried out at room temperature for 40-50 hours.

[0032] Preferably, the reaction rate regulator is prepared by mixing butyl succinic anhydride and 3,5-propyl-1-butyn-3-ol in excess of alcohol.

[0033] The silicone pressure-sensitive adhesive of this invention is obtained by mixing component A and component B and then curing them under heating conditions via hydrosilylation. During hydrosilylation, the reaction rate is relatively fast due to the high reactivity of the Castrol catalyst, which easily leads to product gelation. To control the reaction rate, reagents that slow down the reaction are usually added, but these reagents prevent rapid curing. Therefore, to achieve both rapid curing and avoid product gelation, the reaction rate needs to be adjusted appropriately. The solution provided by this invention is to control the concentration of 3,5-propyl-1-butyn-3-ol in the reaction system by reacting a temperature-responsive butyl succinic anhydride (phase transition temperature 46°C) with a reaction-slowing agent, 3,5-propyl-1-butyn-3-ol (which inhibits the Castrol catalyst). When the temperature is below the phase transition temperature of butyl succinic anhydride, it is in a solid state and hardly reacts with 3,5-propyl-1-butyn-3-ol. However, when the temperature is above 50°C, the reactivity of butyl succinic anhydride gradually increases with temperature after it transforms into a liquid state. Its reaction rate with 3,5-propyl-1-butyn-3-ol also increases, which can appropriately consume 3,5-propyl-1-butyn-3-ol, thereby gradually releasing the catalytic efficiency of the Castel catalyst, and finally achieving temperature-responsive catalytic rapid solidification while avoiding product gelation.

[0034] The reaction principle of the above-mentioned reaction rate regulator is as follows:

[0035]

[0036] As a further preferred embodiment, the reaction rate regulator is used in component B in an amount of 0.1-0.2 parts.

[0037] Secondly, this invention provides a method for preparing a high-temperature resistant, low-peel-strength silicone pressure-sensitive adhesive: Component A and Component B are mixed evenly, an initiator is added, and the mixture is heated to undergo a curing reaction, thereby obtaining the high-temperature resistant, low-peel-strength silicone pressure-sensitive adhesive. The mechanism of the curing reaction is as follows:

[0038]

[0039] Note: In the product of the above reaction formula, the cubic cage-like group refers to the group formed by (divinyldimethyl)phenyl isomer silsesquioxane and (dimethyldihydro)phenyl isomer silsesquioxane.

[0040] In the above curing reaction, under the action of a castor catalyst, the vinyl-terminated silicone oil, vinylmethyl MQ resin, and (bisvinyldimethyl)phenyl isosilsesquioxane in component A, and the hydrogen-containing end-terminated silicone oil, methyl hydrogen-containing MQ resin, and (bismethyldihydro)phenyl isosilsesquioxane in component B undergo a hydrosilylation reaction. The resulting silicone pressure-sensitive adhesive has a three-dimensional cross-linked network structure. During the above process, the viscosity of the reaction system is low, thus eliminating the need for large amounts of organic solvents to dilute and reduce viscosity, making it more environmentally friendly. The silicone pressure-sensitive adhesive obtained after the reaction exhibits low peel strength and excellent heat resistance. A reaction rate regulator is used to control the reaction time for the formation of the three-dimensional cross-linked network structure, preventing excessively rapid cross-linking reaction rates that could lead to product gelation.

[0041] Preferably, the initiator is BPO, and the addition amount is 0.5-1.5 wt%; the curing reaction temperature is 140-160℃, and the time is 1.5-2.5 h.

[0042] Preferably, the peel strength of the high-temperature resistant, low-peel-force silicone pressure-sensitive adhesive is ≤180gf / 25mm.

[0043] Thirdly, the present invention provides the application of (divinyldimethyl)phenyl isosilsesquioxane and (dimethyldihydro)phenyl isosilsesquioxane in reducing the viscosity of silicone pressure-sensitive adhesives before curing or reducing the peel strength of silicone pressure-sensitive adhesives after curing.

[0044] Compared with the prior art, the present invention has the following technical effects:

[0045] (1) The present invention found that adding (divinyldimethyl)phenyl isomer silsesquioxane and (dimethyldihydro)phenyl isomer silsesquioxane, which are rich in phenyl groups, to organosilicon pressure-sensitive adhesives via hydrosilylation can significantly reduce the viscosity of the reaction system, thus eliminating the need for adding large amounts of organic solvents for dilution, which is more environmentally friendly.

[0046] (2) The present invention found that using (divinyldimethyl)phenyl isomer silsesquioxane and (dimethyldihydro)phenyl isomer silsesquioxane, which are rich in phenyl groups, as raw materials for silicone pressure-sensitive adhesives can not only improve the heat resistance of silicone pressure-sensitive adhesives, but also significantly reduce the peel force. Detailed Implementation

[0047] The present invention will be further described below with reference to embodiments.

[0048] General Implementation Examples

[0049] A high-temperature resistant, low-peel-stretch silicone pressure-sensitive adhesive, comprising the following raw materials in parts by weight:

[0050] Component A: 45-55 parts vinyl-terminated silicone oil, 20-30 parts vinyl methyl MQ resin, 20-30 parts (bisvinylbismethyl)phenyl isomersilsesquioxane xylene mixture, 0.1-0.3 parts caster catalyst.

[0051] Component B: 60-70 parts of hydrogen-capped silicone oil, 8-12 parts of methyl hydrogen MQ resin, 20-30 parts of (dimethyl dihydro)phenyl isomeric silsesquioxane xylene mixture, and 0-0.3 parts of reaction rate regulator (preferably 0.1-0.2 parts).

[0052] Preferably, the preparation method of the (divinyldimethyl)phenyl isomeric silsesquioxane xylene mixture includes:

[0053] a) Add tetrahydrofuran, isopropanol, lithium hydroxide, cesium carbonate, and water to a reaction vessel and stir until homogeneous. Add phenyltrimethoxysilane dropwise. After the addition is complete, heat to reflux for 20-30 hours. Cool to -3 to -7°C and slowly add excess hydrochloric acid. Filter, wash at least once each with methanol and acetonitrile, and dry under reduced pressure at room temperature for 20-30 hours to obtain phenyltetrasilanol. The molar ratio of tetrahydrofuran, isopropanol, lithium hydroxide, cesium carbonate, water, phenyltrimethoxysilane, and hydrochloric acid is 140-160 mL : 45-55 mL : 0.06-0.10 mol : 0.003-0.007 mol : 3.4-3.8 g : 0.14-0.18 mol : 0.18-0.22 mol.

[0054] b): A mixture of phenyltetrasilanol, xylene, methylvinyldimethoxysilane, and catalyst (stannous octoate) is reacted at room temperature for 40-50 h to obtain a (divinyldimethyl)phenyl isomeric silsesquioxane-xylene mixture. The molar ratio of phenyltetrasilanol, xylene, and methylvinyldimethoxysilane is 0.008-0.012 mol: 45-55 g: 0.008-0.012 mol.

[0055] Preferably, the preparation method of the (dimethyldihydro)phenyl isomeric silsesquioxane xylene mixture includes: A) adding tetrahydrofuran, isopropanol, lithium hydroxide, cesium carbonate, and water to a reaction vessel and stirring until homogeneous; adding phenyltrimethoxysilane dropwise; heating and refluxing for 20-30 h after the addition is complete; cooling to -3 to -7 °C; slowly adding excess hydrochloric acid; filtering; washing at least once each with methanol and acetonitrile; and drying under reduced pressure at room temperature for 20-30 h to obtain phenyltetrasilanol. The molar ratio of tetrahydrofuran, isopropanol, lithium hydroxide, cesium carbonate, water, phenyltrimethoxysilane, and hydrochloric acid is 140-160 mL : 45-55 mL : 0.06-0.10 mol : 0.003-0.007 mol : 3.4-3.8 g : 0.14-0.18 mol : 0.18-0.22 mol.

[0056] B): A mixture of phenyltetrasilanol, xylene, methyldimethoxysilane, and catalyst (stannous octoate) is reacted at room temperature for 40-50 hours to prepare a (dimethyldihydro)phenyl isomeric silsesquioxane-xylene mixture. The molar ratio of phenyltetrasilanol, xylene, and methyldimethoxysilane is 0.008-0.012 mol: 45-55 g: 0.008-0.012 mol.

[0057] Preferably, the reaction rate regulator is prepared by mixing butyl succinic anhydride and 3,5-propyl-1-butyn-3-ol in excess of alcohol.

[0058] A method for preparing a high-temperature resistant and low-peel-strength silicone pressure-sensitive adhesive: After mixing component A and component B evenly, add BPO to 0.5-1.5 wt%, heat to 140-160℃ and cure for 1.5-2.5 h to obtain a high-temperature resistant and low-peel-strength silicone pressure-sensitive adhesive.

[0059] Example 1

[0060] Preparation of (bisvinyldimethyl)phenyl isomeric silsesquioxane xylene mixture:

[0061] In a 500 mL three-necked flask equipped with a condenser and stirrer, 150 mL of tetrahydrofuran, 50 mL of isopropanol, 1.92 g (0.08 mol) of lithium hydroxide, 1.63 g (0.005 mol) of cesium carbonate, and 3.60 g of double-distilled water were added. After stirring until homogeneous, 31.72 g (0.16 mol) of phenyltrimethoxysilane was slowly added dropwise. After the addition was complete, the mixture was heated to reflux and reacted for 24 h. Then, the temperature was lowered to -5 °C, and 200 mL of 1 mol / L hydrochloric acid was slowly added dropwise. After the addition was complete, the mixture was filtered, washed once each with methanol and acetonitrile, and dried under reduced pressure at room temperature for 24 h to obtain 20.9 g of phenyltetrasilanol (yield 97%).

[0062] Take 10.7 g (0.01 mol) of the above-mentioned phenyltetrasilanol, 50 g of xylene, 1.32 g (0.01 mol) of methylvinyldimethoxysilane, and 5 drops of stannous octoate (approximately 0.05 mL per drop). React at room temperature for 48 h to prepare a (bisvinyldimethyl)phenyl isomeric silsesquioxane-xylene mixture for later use (1b). The preparation route is shown below:

[0063]

[0064] Preparation of (dimethyldihydro)phenyl isomeric silsesquioxane xylene mixture:

[0065] To prepare phenyltetrasilyl alcohol as described above, 10.7 g (0.01 mol) of phenyltetrasilyl alcohol, 50 g of xylene, 1.18 g (0.01 mol) of methyldihydromethoxysilane, and 5 drops of stannous octoate (approximately 0.05 mL per drop) were reacted at room temperature for 48 h to prepare a (dimethyldihydro)phenyl isomeric silsesquioxane-xylene mixture for later use (1B). The preparation route is shown below:

[0066]

[0067] Example 2

[0068] Preparation of component A (A1): 50 parts of vinyl-terminated silicone oil, 25 parts of vinyl methyl MQ resin, 25 parts of 1b mixture (Example 1), and 0.2 parts of caster catalyst were added to a high-speed dispersion planetary mixer. The mixture was stirred for 2 hours at a temperature below 40°C and a vacuum of -0.08 MPa. After stirring until homogeneous, component A1 was obtained.

[0069] Preparation of component A (A2): 55 parts of vinyl-terminated silicone oil, 25 parts of vinyl methyl MQ resin, 20 parts of xylene, and 0.2 parts of caster catalyst were added to a high-speed dispersion planetary mixer. The mixture was stirred for 2 hours at a temperature below 40°C and a vacuum of -0.08 MPa. After stirring evenly, component A2 was obtained.

[0070] Preparation of component A (A3): 50 parts of side-chain vinyl silicone oil, 25 parts of vinyl methyl MQ resin, 25 parts of 1b mixture (Example 1), and 0.2 parts of caster catalyst were added to a high-speed dispersion planetary mixer. The mixture was stirred for 2 hours at a temperature below 40°C under a vacuum of -0.08 MPa. After stirring until homogeneous, component A3 was obtained.

[0071] Preparation of component A (A4): 50 parts of vinyl-terminated silicone oil, 25 parts of vinyl methyl MQ resin, 5 parts of vinyl phenyl silicone oil, 20 parts of xylene, and 0.2 parts of caster catalyst were added to a high-speed planetary mixer. The mixture was stirred for 2 hours at a temperature below 40°C under a vacuum of -0.08 MPa. After stirring until homogeneous, component A4 was obtained.

[0072] Example 3

[0073] Preparation of Component B (B1): 65 parts of hydrogen-containing end-capped silicone oil, 10 parts of methyl hydrogen-containing MQ resin, 25 parts of 1B mixture (Example 1), and 0.2 parts of reaction rate regulator (made by mixing butyl succinic anhydride and 3,5-propyl-1-butyn-3-ol in a molar ratio of 1:1.1) were added to a high-speed dispersion planetary mixer. The mixture was stirred for 2 hours at a temperature below 40°C under a vacuum of -0.08 MPa. After stirring until homogeneous, the mixture was discharged to obtain Component B1.

[0074] Preparation of Component B (B2): 70 parts of hydrogen-containing end-capped silicone oil, 10 parts of methyl hydrogen-containing MQ resin, 20 parts of xylene, and 0.2 parts of reaction rate regulator (made by mixing butyl succinic anhydride and 3,5-propyl-1-butyn-3-ol in a molar ratio of 1:1.1) were added to a high-speed planetary mixer. The mixture was stirred for 2 hours at a temperature below 40°C under a vacuum of -0.08 MPa. After stirring until homogeneous, the mixture was discharged to obtain Component B2.

[0075] Preparation of component B (B3): 65 parts of side-chain hydrogen-containing silicone oil, 10 parts of methyl hydrogen-containing MQ resin, 25 parts of 1B mixture (Example 1), and 0.2 parts of reaction rate regulator (made by mixing butyl succinic anhydride and 3,5-propyl-1-butyn-3-ol in a molar ratio of 1:1.1) were added to a high-speed dispersion planetary mixer. The mixture was stirred for 2 hours at a temperature below 40°C under a vacuum of -0.08 MPa. After stirring until homogeneous, component B3 was obtained.

[0076] Preparation of component B (B4): 65 parts of hydrogen-containing end-capped silicone oil, 10 parts of methyl hydrogen-containing MQ resin, and 25 parts of 1B mixture were added to a high-speed dispersion planetary mixer. The mixture was stirred for 2 hours at a temperature below 40℃ and a vacuum degree of -0.08 MPa. After stirring evenly, component B4 was obtained.

[0077] Example 4

[0078] After mixing components A and B obtained in Examples 2 and 3 in equal mass according to different combinations, 1 wt% BPO was added, and the mixture was slowly heated to 150°C and maintained for 2 hours to prepare an organosilicon pressure-sensitive adhesive.

[0079] Performance testing

[0080] Methyl hydrogen-containing MQ resin, vinylmethyl MQ resin, hydrogen-containing end-capped silicone oil, and vinylphenyl silicone oil were provided by Shandong Dayi Chemical Co., Ltd. The caster catalyst was provided by Shanghai Yuanfan Biotechnology Co., Ltd. The side-chain hydrogen-containing silicone oil and side-chain vinyl silicone oil were provided by Guangdong Chenxi New Materials Technology Co., Ltd. BPO was provided by Shanghai Titan Technology Co., Ltd. The commercially available comparison ratio was provided by the R&D department of Inner Mongolia Hengyecheng Organosilicon Co., Ltd.

[0081] The performance of silicone pressure-sensitive adhesives, obtained by mixing and curing different components A and B under heat, was tested. The test methods and data are as follows: 180° peel strength: tested using a computerized peel tester according to GB / T 2792-2014. Anti-exudation: Silicone pressure-sensitive adhesive strips of 25mm × 200mm were prepared and attached to the glass surface. The prepared samples were placed in a constant temperature and humidity chamber at 85℃ × 85% RH for 168 hours. After removal, the adhesive tape was peeled off to observe the surface condition and determine the grade. The grades were: Excellent: Surface smooth and without exudation when observed with a magnifying glass; Good: Surface with a small amount of exudation when observed with a magnifying glass, but no exudation visible to the naked eye; Poor: A small amount of exudation is visible to the naked eye.

[0082] Temperature resistance: A 25mm × 200mm strip of silicone pressure-sensitive adhesive was prepared, applied to a copper foil surface, and then to a steel plate surface. The strip was placed in a forced-air drying oven at 240℃ for 30 minutes, then removed and cooled to room temperature. The copper foil was then pinched to peel the adhesive strip off the steel plate surface. The condition of the steel plate surface was observed, and the grade was determined. The grades were: Excellent: No residue on the steel plate surface, and the pressure-sensitive adhesive was intact; Good: A small amount of residue on the steel plate surface, and the pressure-sensitive adhesive was mostly intact; Poor: A significant amount of residue on the steel plate surface, and the pressure-sensitive adhesive was not intact.

[0083]

[0084] Analysis of the data in the table above shows that:

[0085] Cured Example 1 has a low viscosity before curing, while also having low peel strength and excellent resistance to exudation and temperature resistance.

[0086] Compared with Curing Example 1, Curing Example 2 uses component 2 which does not contain compound 1B, resulting in lower viscosity, peel strength and temperature resistance before curing compared to Curing Example 1.

[0087] Compared with Curing Example 1, Curing Example 3 differs in that it uses Component B3, in which side-chain hydrogen-containing silicone oil is used instead of hydrogen-end silicone oil. Ultimately, it was found that the viscosity and peel strength before curing both increased.

[0088] Compared with Curing Example 1, Curing Example 4 did not contain a reaction rate regulator in component B4, resulting in an excessively fast curing reaction that led to product gelation, making it impossible to test relevant data.

[0089] Compared with Curing Example 1, Curing Example 5 uses component A2 which does not contain compound 1b, resulting in its viscosity, peel strength and temperature resistance before curing being inferior to Curing Example 1.

[0090] Compared with Curing Example 1, Curing Example 6 differs in that it uses Component A3, in which side-chain vinyl silicone oil is used instead of vinyl-terminated silicone oil. Data shows that the viscosity and peel strength before curing both increased.

[0091] Compared with Curing Example 1, Curing Example 7 was different in that it used Component A4, in which vinyl phenyl silicone oil replaced Compound 1b. As a result, the viscosity, peel strength and temperature resistance data before curing were found to be significantly worse.

[0092] Compared with Curing Example 1, Curing Example 8 uses a combination of Component A 2 and Component B 3. Component A 2 lacks Compound 1b, and Component B 3 uses hydrogen-containing side-chain silicone oil instead of hydrogen-end silicone oil. The results showed that the viscosity, peel strength and temperature resistance before curing were significantly worse than those of Curing Example 1.

[0093] Compared with Curing Example 1, Curing Example 9 differs in that it uses a combination of Component A (3 components) and Component B (3 components). In Component A (3 components), side-chain vinyl silicone oil is used instead of vinyl-terminated silicone oil, and in Component B (3 components), side-chain hydrogen-containing silicone oil is used instead of hydrogen-containing end-terminated silicone oil. Ultimately, it was found that the viscosity and peel strength performance decreased before curing.

[0094] Compared with Curing Example 1, Curing Example 10 uses a combination of Component A (4 components) and Component B (2 components). In Component A (4 components), vinyl phenyl silicone oil replaces Compound 1b, and Component B (2 components) lacks Compound 1B. As a result, it was found that the data in all performance aspects were significantly deteriorated.

[0095] Compared with Curing Example 1, Curing Example 11 was different in that it used a combination of Component A 2 and Component B 2. Component A 2 did not contain Compound 1b, and Component B 2 did not contain Compound 1B. The results showed that all properties were significantly reduced.

[0096] Unless otherwise specified, the raw materials and equipment used in this invention are all commonly used in the field; unless otherwise specified, the methods used in this invention are all conventional methods in the field.

[0097] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications, alterations, and equivalent transformations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

Claims

1. A high temperature resistant low peel force silicone pressure sensitive adhesive, characterized by: The following raw materials are included by weight parts: Group A: vinyl-terminated silicone oil 45-55 parts, vinyl methyl MQ resin 20-30 parts, (bis-vinyl dimethyl) phenyl isomeromeric silsesquioxane xylene mixture 20-30 parts obtained by reacting phenylsilanol, xylene and methyl vinyl dimethoxysilane in a ratio of 0.008-0.012 mol: 45-55 g: 0.008-0.012 mol, and Karstedt catalyst 0.1-0.3 parts; The structural formula of the (bis-vinyl dimethyl) phenyl isomeromeric silsesquioxane is: Group B: hydrogen-terminated silicone oil 60-70 parts, methyl hydrogen MQ resin 8-12 parts, (bis-methyl dihydrogen) phenyl isomeromeric silsesquioxane xylene mixture 20-30 parts obtained by reacting phenylsilanol, xylene and methyl hydrogen dimethoxysilane in a ratio of 0.008-0.012 mol: 45-55 g: 0.008-0.012 mol, and reaction rate modifier 0.1-0.3 parts; The structural formula of the (bis-methyl dihydrogen) phenyl isomeromeric silsesquioxane is:

2. The silicone pressure sensitive adhesive of claim 1, wherein: The preparation method of the (bis-vinyl dimethyl) phenyl isomeromeric silsesquioxane xylene mixture includes: a): Add tetrahydrofuran, isopropyl alcohol, lithium hydroxide, cesium carbonate and water into a reaction container and stir until uniform, then drop phenyltrimethoxysilane, heat to reflux after dropping, cool down, drop excess hydrochloric acid, filter, wash and dry to obtain phenylsilanol; b): Mix phenylsilanol, xylene, methyl vinyl dimethoxysilane and catalyst, then react to obtain (bis-vinyl dimethyl) phenyl isomeromeric silsesquioxane xylene mixture.

3. The silicone pressure sensitive adhesive of claim 1, wherein: The preparation method of the (bis-methyl dihydrogen) phenyl isomeromeric silsesquioxane xylene mixture includes: A): Add tetrahydrofuran, isopropyl alcohol, lithium hydroxide, cesium carbonate and water into a reaction container and stir until uniform, then drop phenyltrimethoxysilane, heat to reflux after dropping, cool down, slowly drop excess hydrochloric acid, filter, wash and dry to obtain phenylsilanol; B): Mix phenylsilanol, xylene, methyl hydrogen dimethoxysilane and catalyst, then react to obtain (bis-methyl dihydrogen) phenyl isomeromeric silsesquioxane xylene mixture.

4. The silicone pressure sensitive adhesive of claim 1, wherein: The reaction rate modifier is obtained by mixing butyl succinic anhydride and 3,5-propyl-1-butyn-3-ol in alcohol excess.

5. A process for the production of a high temperature resistant low peel force silicone pressure sensitive adhesive according to any one of claims 1 to 4, characterized in that: Mix Group A and Group B uniformly, then add initiator, heat and carry out curing reaction to obtain high-temperature-resistant low-peeling-force silicone pressure-sensitive adhesive.

6. The production method according to claim 5, characterized by: The initiator is BPO and the addition amount is 0.5-1.5 wt%.

7. The production method according to claim 5, wherein: The curing reaction temperature is 140-160°C and the time is 1.5-2.5 h.

8. The high temperature resistant low peel force silicone pressure sensitive adhesive according to any one of claims 1 to 4 or the high temperature resistant low peel force silicone pressure sensitive adhesive obtained by the preparation method of claim 5 or 6 or 7, characterized in that: The peeling strength is ≤180 gf / 25 mm.

9. Application of (bis-vinyl dimethyl) phenyl isomeromeric silsesquioxane and (bis-methyl dihydrogen) phenyl isomeromeric silsesquioxane in reducing the viscosity of silicone pressure-sensitive adhesive before curing or reducing the peeling force of silicone pressure-sensitive adhesive after curing, characterized in that: The structural formula of the (bis-vinyl dimethyl) phenyl isomeromeric silsesquioxane is: The structural formula of the (bis-methyl dihydrogen) phenyl isomeromeric silsesquioxane is:

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