Dealcoholized organosilicon sealant and preparation method thereof

Abstract

The invention provides a dealcoholized organosilicon sealant and a preparation method thereof, and belongs to the technical field of sealants, the dealcoholized organosilicon sealant comprises the following components by weight: 100 parts of alkoxy-terminated polydimethylsiloxane; 5-30 parts by weight of a filler; 0.3-15 parts by weight of a cross-linking agent; 0.05-3 parts by weight of a catalyst; 0.1 to 10 parts by weight of a tackifier; the tackifier with a specific structure is introduced into the dealcoholized organic silicon sealant, so that relatively high active group components can be provided, and the dealcoholized organic silicon sealant provided by the invention has excellent bonding performance on composite base materials such as various metals or plastics.

Description

Technical Field

[0001] This invention belongs to the field of sealant chemistry and relates to a de-alcoholized organosilicon sealant and its preparation method. Background Technology

[0002] De-alcoholized sealants refer to room temperature vulcanizing silicone rubbers used in industrial electronics. They are named for the release of methanol or ethanol molecules during the vulcanization process. Using silica as a reinforcing filler, the resulting adhesive is transparent or semi-transparent, and its primary applications are bonding and sealing in electronics, semiconductors, and radar systems.

[0003] Currently, common alcohol-based transparent silicone sealants mainly include two types: alcohol-based and methanol-based. Alcohol-based transparent silicone sealants, commonly known as Nanda transparent sealants, are prepared using Nanda α-crosslinking agents and silane coupling agents. Due to their poor resistance to yellowing and difficulty in controlling rapid surface drying, their application range is currently limited. Methanol-based transparent silicone sealants include organotin-catalyzed and organotitanium-catalyzed types. Organotin-catalyzed methanol-based transparent silicone sealants have poor storage stability, requiring the introduction of storage stabilizers with strong odors. Furthermore, organotin is toxic and environmentally unfriendly, limiting their application scenarios. Compared to tin-catalyzed methanol-based and methanol-based transparent silicone sealants, organotitanium-catalyzed sealants are more environmentally friendly and have better storage stability, showing great application potential in specific industries. However, organotitanium-catalyzed methanol-based transparent silicone sealants cannot use colored titanate catalysts, resulting in poor adhesion. Summary of the Invention

[0004] To address the shortcomings of existing technologies, the present invention aims to provide a dealcohol-based silicone sealant and its preparation method.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] On one hand, the present invention provides a dealcohol-based silicone sealant, comprising, by weight, the following components:

[0007] 100 parts by weight of alkoxy-terminated polydimethylsiloxane;

[0008] 5-30 parts by weight of filler;

[0009] Crosslinking agent 0.3-15 parts by weight;

[0010] Catalyst: 0.05-3 parts by weight;

[0011] Thickening agent 0.1-10 parts by weight.

[0012] The method for preparing the thickener includes:

[0013] (1) Phenyl glycidyl ether reacts with acrylic acid to obtain a prepolymer;

[0014] (2) The prepolymer, hydrogen-containing polysiloxane and γ-methacryloxypropyltrimethoxysilane are reacted under the catalysis of a platinum catalyst to obtain the thickener.

[0015] This invention prepares a tackifier by introducing a biphenyl-structured compound. In this tackifier, the biphenyl structure exhibits strong electronegativity and a π-electron conjugation effect. Adding it to a dealcohol-type silicone sealant enhances the adhesion of the active groups to various composite substrates such as metals or plastics, particularly improving the sealant's adhesion at high temperatures and exhibiting superior storage stability. In other words, by introducing a tackifier into a dealcohol-type silicone sealant, this invention not only achieves excellent adhesion performance but also superior storage stability.

[0016] In this invention, the filler (5-30 parts by weight) can be 5 parts by weight, 10 parts by weight, 25 parts by weight, 28 parts by weight, 20 parts by weight, 22 parts by weight, 25 parts by weight, 28 parts by weight, 30 parts by weight, etc.; the crosslinking agent (0.3-15 parts by weight) can be 0.3 parts by weight, 1 part by weight, 2 parts by weight, 5 parts by weight, 8 parts by weight, 10 parts by weight, 12 parts by weight, 15 parts by weight, etc.; the catalyst (0.05-3 parts by weight) can be 0.05 parts by weight, 0.1 parts by weight, 0.2 parts by weight, 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, etc.; and the tackifier (0.1-10 parts by weight) can be 0.1 parts by weight, 1 part by weight, 2 parts by weight, 3 parts by weight, 5 parts by weight, 6 parts by weight, 8 parts by weight, 10 parts by weight, etc.

[0017] Preferably, the mass ratio of the phenyl glycidyl ether to acrylic acid is (2-5):1, for example, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1, 5:1, etc.

[0018] The phenyl glycidyl ether has the structure shown in Formula I:

[0019] ;

[0020] Formula I;

[0021] Among them, R 1 The alkylene group is selected from C1-C5, such as methylene, ethylene, propylene, etc., with methylene and isopropylene being preferred.

[0022] Preferably, the phenyl glycidyl ether comprises bisphenol F diglycidyl ether and / or bisphenol A diglycidyl ether, having the following structure:

[0023] and / or .

[0024] The present invention does not impose any special restrictions on the source of the phenyl glycidyl ether; commercially available products known to those skilled in the art or self-made products prepared according to preparation methods known to those skilled in the art are acceptable.

[0025] The acrylic compounds include any one or a combination of at least two of acrylic acid, methacrylic acid, 2-ethylacrylic acid, or 2-propylacrylic acid, preferably acrylic acid and / or methacrylic acid. The present invention does not impose any particular limitation on the source of the acrylic compounds; commercially available products well known to those skilled in the art or self-prepared products according to methods well known to those skilled in the art are acceptable.

[0026] The reaction in step (1) is carried out under the catalysis of sodium hydroxide.

[0027] Step (1) also includes a retarder, which is p-hydroxyanisole.

[0028] The reaction temperature in step (1) is 90-110℃, for example 90℃, 95℃, 100℃, 105℃, 110℃, and the time is 4-6 h, for example 4 h, 4.5 h, 5 h, 5.5 h, 6 h, etc.

[0029] Preferably, step (1) specifically includes:

[0030] Phenyl glycidyl ether, acrylic acid compound, sodium hydroxide catalyst and p-hydroxyanisole are mixed and stirred and heated to 90-110℃ for 4-6 h. Then, low-boiling substances are removed by vacuum distillation for 3-4 h, for example 3 h, 3.2 h, 3.5 h, 3.8 h, 4 h, etc., to obtain the prepolymer.

[0031] Preferably, in step (1), the sodium hydroxide catalyst is added in the form of a sodium hydroxide solution. Preferably, the concentration of the sodium hydroxide solution is 0.2-0.8%, such as 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, etc. Preferably, the amount of sodium hydroxide solution added is 0.02-0.2% of the total mass of the phenyl glycidyl ether and acrylic acid compound, such as 0.02%, 0.05%, 0.08%, 0.1%, 0.12%, 0.15%, 0.18%, 0.2%, etc.

[0032] Preferably, the amount of p-hydroxyanisole added is 0.1-1% of the total mass of the phenyl glycidyl ether and acrylic acid compound, for example, 0.1%, 0.2%, 0.4%, 0.5%, 0.6%, 0.8%, 1%, etc.

[0033] Preferably, the hydrogen-containing polysiloxane includes any one or a combination of at least two of the following: linear-side hydrogen-containing polysiloxane, linear-end hydrogen-containing polysiloxane, linear-end-side hydrogen-containing polysiloxane, or 2,4,6,8-tetramethylcyclotetrasiloxane, and more preferably linear-side hydrogen-containing polysiloxane and / or 2,4,6,8-tetramethylcyclotetrasiloxane.

[0034] The hydrogen-containing polysiloxane has a hydrogen molar content of 1-25 mmol / g, for example, 1 mmol / g, 2 mmol / g, 5 mmol / g, 8 mmol / g, 10 mmol / g, 12 mmol / g, 15 mmol / g, 18 mmol / g, 20 mmol / g, and 25 mmol / g, preferably 5-18 mmol / g. The present invention does not impose any special restrictions on the source of the hydrogen-containing polysiloxane; commercially available products well known to those skilled in the art or self-made products prepared according to methods well known to those skilled in the art are acceptable.

[0035] The mass ratio of the prepolymer, the hydrogen-containing polysiloxane, and γ-methacryloxypropyltrimethoxysilane is (30-60):100:(20-40), where 30-60 can be 30, 35, 40, 45, 50, 55, 60, etc., and 20-40 can be 20, 22, 25, 28, 30, 32, 35, 38, 40, etc.

[0036] The reaction temperature in step (2) is 60-80℃, for example 60℃, 65℃, 70℃, 75℃, 80℃, etc., and the time is 3-4 h, for example 3 h, 3.2 h, 3.5 h, 3.8 h, 4 h, etc.

[0037] Preferably, the platinum content in the platinum catalyst is 1000-5000 ppm, such as 1000 ppm, 2000 ppm, 3000 ppm, 4000 ppm, 5000 ppm, etc., and is preferably any one or a combination of at least two of chloroplatinic acid, platinum-vinyl complex, and platinum-acetylene complex.

[0038] Preferably, step (2) specifically includes:

[0039] At a controlled temperature of 60-80℃, hydrogen-containing polysiloxane, γ-methacryloyloxypropyltrimethoxysilane and platinum catalyst were added to the prepolymer, and the reaction was continued under nitrogen atmosphere for 3-4 h to obtain the thickener.

[0040] In this invention, the thickener obtained by the preparation method provided by this invention has the following structure:

[0041] ;

[0042] or,

[0043] .

[0044] In this invention, the content of the thickener is preferably 0.3-2 parts by weight, such as 0.3 parts by weight, 0.5 parts by weight, 0.8 parts by weight, 1 part by weight, 1.2 parts by weight, 1.5 parts by weight, 1.8 parts by weight, 2 parts by weight, etc.

[0045] Preferably, the alkoxy-terminated polydimethylsiloxane has the following structure:

[0046]

[0047] Where m is an integer representing the viscosity of polydimethylsiloxane at 25°C that is between 10 and 300,000 mPa·s, such as 10 mPa·s, 100 mPa·s, 1000 mPa·s, 10000 mPa·s, 20000 mPa·s, 50000 mPa·s, 100000 mPa·s, 300000 mPa·s, etc.

[0048] Preferably, the alkoxy-terminated polydimethylsiloxane has a viscosity of 500-150000 mPa·s at 25°C, such as 500 mPa·s, 1000 mPa·s, 2000 mPa·s, 5000 mPa·s, 8000 mPa·s, 10000 mPa·s, 50000 mPa·s, 80000 mPa·s, 100000 mPa·s, 120000 mPa·s, 150000 mPa·s, etc., and more preferably 5000-100000 mPa·s.

[0049] The present invention does not impose any special restrictions on the source of the alkoxy-terminated polydimethylsiloxane; commercially available products well known to those skilled in the art or self-made products prepared according to preparation methods well known to those skilled in the art are acceptable.

[0050] Preferably, the filler is fumed silica with a specific surface area of ​​100-300 m². 2 / g, for example, 100 m 2 / g、120m 2 / g, 150 m 2 / g、180 m 2 / g、200 m 2 / g、220 m 2 / g、250 m 2 / g、280 m 2 / g、300 m 2 / g etc.

[0051] Preferably, the fumed silica treated with a hydrophobic method is used in this invention, and more preferably, it is fumed silica treated with dimethyldichlorosilane, with a preferred specific surface area of ​​150-250 m². 2 / g. This invention does not impose any special restrictions on the source of the filler described above; commercially available products well-known to those skilled in the art or self-made products prepared according to methods well-known to those skilled in the art are acceptable. In this invention, the filler is preferably 10-60 parts by weight, for example, 10 parts by weight, 20 parts by weight, 30 parts by weight, 40 parts by weight, 50 parts by weight, 60 parts by weight, etc.

[0052] Preferably, the crosslinking agent is a silane organic compound containing at least three alkoxy active groups, selected from any one or a combination of at least two of methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, ethyltrimethoxysilane, tetramethoxysilane, or tetraethoxysilane, and more preferably any one or a combination of at least two of methyltrimethoxysilane, vinyltrimethoxysilane, or vinyltriethoxysilane. The present invention does not impose any particular limitation on the source of the crosslinking agent; commercially available products well known to those skilled in the art or self-made products prepared according to methods well known to those skilled in the art are acceptable. In the present invention, the crosslinking agent is preferably 0.3-10 parts by weight, for example, 0.3 parts by weight, 1 part by weight, 2 parts by weight, 3 parts by weight, 4 parts by weight, 5 parts by weight, 6 parts by weight, 7 parts by weight, 8 parts by weight, 9 parts by weight, 10 parts by weight, etc.

[0053] Preferably, the catalyst comprises a titanate catalyst and / or an aluminate catalyst.

[0054] Preferably, the catalyst comprises any one or a combination of at least two of tetraethyl titanate, isopropyl titanate, tetrabutyl titanate, tetraisobutyl titanate, tetraisooctyl titanate, or diisopropyl aluminate (ethyl acetoacetate), and more preferably a combination of any one or a combination of at least two of tetraethyl titanate, tetraisobutyl titanate, or diisopropyl aluminate (ethyl acetoacetate).

[0055] The de-alcoholized silicone sealant provided by this invention has high transparency, excellent adhesion to a variety of substrates at both room temperature and high temperature, and excellent resistance to double 85. The preparation method is simple and easy to implement.

[0056] In some embodiments of the present invention, the dealcoholized silicone sealant comprises, by weight:

[0057] 100 parts by weight of alkoxy-terminated polydimethylsiloxane;

[0058] 10-30 parts by weight of filler;

[0059] 1-3 parts by weight of crosslinking agent;

[0060] Catalyst: 0.1-1 parts by weight;

[0061] Thickener 0.3-2 parts by weight.

[0062] Secondly, the present invention provides a method for preparing the de-alcoholized silicone sealant as described in the first aspect, the method comprising:

[0063] The components in the formula are mixed to obtain the de-alcoholized silicone sealant.

[0064] Preferably, the preparation method includes:

[0065] S1. Mix the formulated amount of alkoxy-terminated polydimethylsiloxane and filler to obtain the base material;

[0066] S2. The base material is mixed with the crosslinking agent, catalyst and tackifier, and degassed to obtain the de-alcoholized silicone sealant.

[0067] In some embodiments of the present invention, the preparation method includes:

[0068] S1. The alkoxy-terminated polydimethylsiloxane and filler are added to a high-speed planetary mixer and degassed and dispersed for 1-5 hours, such as 30-90℃, for example 30℃, 40℃, 50℃, 60℃, 70℃, 80℃, 90℃, etc., with a vacuum degree not lower than -0.08 MPa (for example -0.08 MPa, -0.09 MPa, etc.), to obtain the base material;

[0069] S2. At room temperature and in a nitrogen atmosphere, the base material, crosslinking agent, catalyst and tackifier are mixed until uniform. Finally, the mixture is degassed for 10-30 min, such as 10 min, 15 min, 20 min, 25 min, 30 min, etc., under a vacuum degree not lower than -0.08 MPa (e.g. -0.08 MPa, -0.09 MPa, etc.), to obtain the de-alcoholized silicone sealant.

[0070] Compared with the prior art, the present invention has the following beneficial effects:

[0071] (1) By introducing a tackifier with a specific structure in this invention, a high active group content can be provided, so that the de-alcoholized silicone sealant provided by this invention has excellent adhesion performance to a variety of composite substrates such as metals or plastics.

[0072] (2) The preparation method provided by the present invention is simple and easy to implement, with mild conditions, and is suitable for large-scale production and application. Detailed Implementation

[0073] The technical solution of the present invention will be further illustrated below through specific embodiments. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the invention in any way.

[0074] Unless otherwise specified, the raw materials involved in the following specific embodiments of the present invention are all conventional materials in the art, and can be purchased from commercially available products. Some raw material information is as follows:

[0075] Alkoxy-terminated polydimethylsiloxane 1: viscosity 20000 mPa·s, purchased from Jiangsu Kexing New Materials, J200;

[0076] Alkoxy-terminated polydimethylsiloxane 2: viscosity 5000 mPa·s, purchased from Orange Sky New Materials, O-F5000;

[0077] Silica 1: Gas-phase method, hydrophobic treatment with dimethyldichlorosilane, specific surface area of ​​200 m² 2 / g, purchased from Wacker Chemie, Germany, HDK H20;

[0078] Silica 2: Gas phase method, hydrophobic treatment with dimethyldichlorosilane, specific surface area of ​​220 m² 2 / g, purchased from Evonik, Aerosil R976 s;

[0079] Silica 3: Gas phase method, hydrophobic treatment with dimethyldichlorosilane, specific surface area of ​​150 m² 2 / g, purchased from Evonik, Aerosil R974;

[0080] Silica 4: Fumed silica, specific surface area 100 m² 2 / g, purchased from Evonik, Aerosil 90;

[0081] Hydrogen-containing polysiloxane 1: Linear hydrogen-containing polysiloxane with a hydrogen molar content of 7 mmol / g, purchased from Ambiar, Andsil XL-10;

[0082] Hydrogen-containing polysiloxane 2: Linear side hydrogen-containing polysiloxane with a hydrogen molar content of 7 mmol / g, purchased from Haiduo New Materials, DTH-075t-50;

[0083] Hydrogen-containing polysiloxane 3: 2,4,6,8-tetramethylcyclotetrasiloxane, purchased from Jiangxi Betterley New Materials, D4H.

[0084] Preparation Example 1

[0085] This preparation example provides a method for preparing a thickener, as follows:

[0086] (1) 30 parts by weight of bisphenol F diglycidyl ether, 10 parts by weight of acrylic acid, 0.3 parts by weight of KOH catalyst with a concentration of 0.7% and 0.1 parts by weight of p-hydroxyanisole were added to a three-necked flask equipped with a stirrer and a reflux condenser. The mixture was stirred and heated at a stirring speed of 200 r / min and a temperature of 100℃ for 4 h. Then, the low-boiling substances were removed under reduced pressure for 3 h to obtain the prepolymer.

[0087] (2) Add 40 parts by weight of linear hydrogen-containing polysiloxane with a hydrogen molar content of 7 mmol / g, 5 parts by weight of γ-methacryloyloxypropyltrimethoxysilane, and 0.05 parts by weight of chloroplatinic acid with a platinum content of 2000 ppm to the prepolymer. Set the temperature to 80℃, the stirring speed to 500 r / min, and stir the reaction for 3 h under nitrogen protection to obtain thickener 1.

[0088] Preparation Example 2

[0089] This preparation example provides a method for preparing a thickener, as follows:

[0090] (1) 40 parts by weight of bisphenol A diglycidyl ether, 8 parts by weight of methacrylic acid, 0.6 parts by weight of KOH catalyst with a concentration of 0.5% and 0.3 parts by weight of p-hydroxyanisole were added to a three-necked flask equipped with a stirrer and a reflux condenser. The mixture was stirred and heated at a stirring speed of 200 r / min and a temperature of 90℃ for 6 h. Then, the low-boiling substances were removed under reduced pressure for 3 h to obtain the prepolymer.

[0091] (2) Add 30 parts by weight of linear hydrogen-containing polysiloxane with a hydrogen molar content of 13 mmol / g, 8 parts by weight of γ-methacryloyloxypropyltrimethoxysilane, and 0.08 parts by weight of platinum-vinyl complex with a platinum content of 2000 ppm to the prepolymer. Set the temperature to 60℃, the stirring speed to 500 r / min, and stir the reaction for 4 h under nitrogen protection to obtain thickener 2.

[0092] Preparation Example 3

[0093] This preparation example provides a method for preparing a thickener, as follows:

[0094] (1) 20 parts by weight of bisphenol A diglycidyl ether, 10 parts by weight of acrylic acid, 0.2 parts by weight of KOH catalyst with a concentration of 0.7% and 0.3 parts by weight of p-hydroxyanisole were added to a three-necked flask equipped with a stirrer and a reflux condenser. The mixture was stirred and heated at a stirring speed of 200 r / min and a temperature of 110℃ for 5 h. Then, the low-boiling substances were removed under reduced pressure for 4 h to obtain the prepolymer.

[0095] (2) Add 15 parts by weight of 2,4,6,8-tetramethylcyclotetrasiloxane, 2 parts by weight of γ-methacryloyloxypropyltrimethoxysilane and 0.1 parts by weight of platinum-vinyl complex with a platinum content of 2000 ppm to the prepolymer, set the temperature to 70℃, the stirring speed to 500 r / min, and stir the reaction for 3 h under nitrogen protection to obtain thickener 3.

[0096] Comparative Preparation Example 1

[0097] This comparative preparation example provides a method for preparing a thickener, as follows:

[0098] The only difference from Preparation Example 1 is that in this comparative preparation example 1, bisphenol F diglycidyl ether was not added in step (1), and 40 parts by weight of acrylic acid were directly added, which was designated as thickener 4.

[0099] Comparative Preparation Example 2

[0100] This comparative preparation example provides a method for preparing a thickener, as follows:

[0101] The only difference from Preparation Example 1 is that in this comparative preparation example 1, bisphenol F diglycidyl ether in step (1) is replaced with an equal mass of ethylene glycol diglycidyl ether, denoted as thickener 5.

[0102] Examples 1-7

[0103] This embodiment provides a dealcohol-based silicone sealant and its preparation method, wherein the components and their weight parts are shown in Table 1:

[0104] Table 1

[0105] The preparation method is as follows:

[0106] (1) Alkoxy-terminated polydimethylsiloxane and fumed silica were added to a high-speed planetary disperser and stirred. The temperature was heated to 60°C and vacuum degassed and dispersed at -0.08 MPa for 2.5 h to obtain the base material.

[0107] (2) Cool the base material to below 50°C, add the crosslinking agent, and stir for 10 min under a nitrogen atmosphere until the mixture is uniform; then add the catalyst and continue stirring for 10 min under a nitrogen atmosphere until the mixture is uniform; finally add the tackifier and stir for 10 min under a nitrogen atmosphere until the mixture is uniform; finally degas for 20 min under a vacuum of not less than -0.08 MPa to obtain the de-alcoholized transparent silicone sealant.

[0108] Comparative Example 1

[0109] This comparative example provides a de-alcoholized silicone sealant and its preparation method.

[0110] The difference from Example 1 is that no thickener was added in this comparative example.

[0111] Comparative Examples 2-3

[0112] This comparative example provides a de-alcoholized silicone sealant and its preparation method.

[0113] The difference from Example 1 is that, in this comparative example, the tackifier is replaced with the tackifier provided in Comparative Preparation Examples 1-2.

[0114] Performance testing

[0115] The performance of the sealants provided in the examples and comparative examples was tested using the following methods:

[0116] (1) The shear strength of the sealant against ADC12 aluminum, PC, and PBT+GF30% was determined according to the test method described in GB / T7124-2008 Determination of Tensile Shear Strength of Adhesives;

[0117] (2) The tensile strength shall be tested according to the test method described in GB / T 528 Rubber Tensile Tear Test Method;

[0118] (3) Aging resistance: After curing for 7 days at 25±2℃ and 50±3℃, high temperature aging at 125℃ and aging at 85℃ / 85%RH for 1500 h were carried out respectively, and the shear strength and tensile strength were tested according to the above test standards after aging.

[0119] Among them, curing at 25±2℃ and 50±3℃ for 7 days is recorded as condition T1, aging at 125℃ for 1500 h is recorded as condition T2, and aging at 85℃ / 85%RH for 1500 h is recorded as condition T3.

[0120] The test results are shown in Table 2-3:

[0121] Table 2

[0122] Table 3

[0123] Note: Shear strength is measured in MPa, CF represents cohesive failure, and AF represents interfacial failure.

[0124] As demonstrated by the examples and performance tests, the present invention, by introducing a tackifier with a specific structure into the de-alcoholized silicone sealant, can utilize the π-electron conjugation effect and strong electronegativity of the biphenyl structure in the tackifier to improve the adhesion of the active groups to various metal and plastic composite substrates.

[0125] (4) High temperature shear: The shear sheet made of sealant is placed in a constant temperature box at 110±3℃ for 2 min, and the shear strength of ADC12 aluminum, PC, PBT+GF30% is determined in a high temperature environment at 110±3℃ according to the test method described in GB / T7124-2008 Determination of tensile shear strength of adhesives.

[0126] The test results are shown in Table 4:

[0127] Table 4

[0128] Note: Shear strength is measured in MPa, CF represents cohesive failure, and AF represents interfacial failure.

[0129] As demonstrated by the examples and performance tests, the sealant provided by the present invention still exhibits excellent bonding performance at high temperatures.

[0130] In Table 2-4:

[0131] As can be seen from the comparison between Examples 1-3 and Examples 4-6, when the amounts of each component of the de-alcoholized silicone sealant provided by the present invention are within the preferred range, the resulting sealant has a better effect.

[0132] As can be seen from the comparison between Example 1 and Example 7, the present invention preferably uses hydrophobically treated fumed silica as a filler.

[0133] As can be seen from the comparison of Example 1 and Comparative Examples 1-3, the tackifier with a specific structure introduced in this invention can greatly increase the adhesive performance and anti-aging performance of the sealant, especially the adhesive performance at high temperatures.

[0134] The present invention has been illustrated through the above embodiments, but the present invention is not limited to the above process steps, that is, it does not mean that the present invention must rely on the above process steps to be implemented. Those skilled in the art should understand that any improvements to the present invention, equivalent substitutions of the raw materials used in the present invention, additions of auxiliary components, and selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A de-alcoholized silicone sealant, characterized in that, Based on parts by weight, it comprises the following components: 100 parts by weight of alkoxy-terminated polydimethylsiloxane; 5-30 parts by weight of filler; Crosslinking agent 0.3-15 parts by weight; Catalyst: 0.05-3 parts by weight; Tackifier 0.1-10 parts by weight; The method for preparing the thickener includes: (1) Phenyl glycidyl ether reacts with acrylic compounds to obtain a prepolymer; (2) The prepolymer, hydrogen-containing polysiloxane and γ-methacryloxypropyltrimethoxysilane are reacted under the catalysis of a platinum catalyst to obtain the thickener.

2. The de-alcoholized silicone sealant according to claim 1, characterized in that, The mass ratio of the phenyl glycidyl ether to acrylic acid is (2-5):1; The phenyl glycidyl ether has the structure shown in Formula I: ； Formula I; Among them, R 1 Selected from C1-C5 alkylene groups; The acrylic compounds include any one or a combination of at least two of acrylic acid, methacrylic acid, 2-ethylacrylic acid, or 2-propylacrylic acid.

3. The de-alcoholized silicone sealant according to claim 1, characterized in that, The reaction in step (1) is carried out under the catalysis of sodium hydroxide; Step (1) also includes a retarder, wherein the retarder is p-hydroxyanisole; The reaction in step (1) is carried out at a temperature of 90-110℃ for 4-6 hours.

4. The de-alcoholized silicone sealant according to claim 1, characterized in that, The hydrogen-containing polysiloxane includes any one or a combination of at least two of the following: linear-side hydrogen-containing polysiloxane, linear-end hydrogen-containing polysiloxane, linear-end-side hydrogen-containing polysiloxane, or 2,4,6,8-tetramethylcyclotetrasiloxane. The hydrogen-containing polysiloxane has a hydrogen molar content of 1-25 mmol / g; The mass ratio of the prepolymer, the hydrogen-containing polysiloxane, and γ-methacryloyloxypropyltrimethoxysilane is (30-60):100:(20-40); The reaction in step (2) is carried out at a temperature of 60-80℃ for 3-4 hours.

5. The de-alcoholized silicone sealant according to any one of claims 1-4, characterized in that, The alkoxy-terminated polydimethylsiloxane has a viscosity of 500-150000 mPa·s at 25°C.

6. The de-alcoholized silicone sealant according to any one of claims 1-4, characterized in that, The filler is fumed silica with a specific surface area of ​​100-300 m². 2 / g.

7. The de-alcoholized silicone sealant according to any one of claims 1-4, characterized in that, The crosslinking agent is a silane organic compound containing at least three alkoxy active groups, selected from any one or a combination of at least two of methyltrimethoxysilane, methyltriethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, ethyltrimethoxysilane, tetramethoxysilane, or tetraethoxysilane.

8. The de-alcoholized silicone sealant according to any one of claims 1-4, characterized in that, The catalysts include titanate catalysts and / or aluminate catalysts.

9. A method for preparing a dealcohol-based silicone sealant as described in any one of claims 1-8, characterized in that, The preparation method includes: The components in the formula are mixed to obtain the de-alcoholized silicone sealant.

10. The preparation method according to claim 9, characterized in that, The preparation method includes: S1. Mix the formulated amount of alkoxy-terminated polydimethylsiloxane and filler to obtain the base material; S2. The base material is mixed with the crosslinking agent, catalyst and tackifier, and degassed to obtain the de-alcoholized silicone sealant.

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