A silicone adhesion promoter, its preparation method and use

Abstract

This invention provides an organosilicon tackifier, its preparation method, and its application. The raw materials for preparing the organosilicon tackifier include the following components: phenylsilanol, siloxane monomers, small molecule diols, and a catalyst. The siloxane monomers include epoxy siloxane monomers, alkenyl siloxane monomers, dialkoxysilanes, and trialkoxysilanes. In this invention, phenylsilanol is used as the molecular backbone, significantly improving the refractive index of the organosilicon tackifier. The compounded siloxane monomers construct a multifunctional crosslinking system with both reactivity and excellent adhesive properties. The introduction of small molecule diols significantly improves the adhesion of silicone rubber to aluminum plates and plastics. The organosilicon tackifier exhibits excellent heat resistance and UV yellowing resistance, meeting the requirements of high-end optical applications.

Description

Technical Field

[0001] This invention belongs to the field of organosilicon tackifier technology, and particularly relates to an organosilicon tackifier, its preparation method and application. Background Technology

[0002] With the rapid development of display devices such as flexible displays, automotive displays, and touch panels towards higher resolution, thinner profiles, and higher reliability, increasingly stringent comprehensive performance requirements are being placed on optical bonding materials. Optical bonding and adhesive materials not only need to possess optical matching characteristics such as high refractive index and high transmittance, but also need to meet long-term reliability requirements such as low stress, resistance to high and low temperatures, and resistance to aging.

[0003] Addition-type silicone rubber has broad application prospects in the field of optical bonding and adhesion of display devices due to its lack of small molecule release during curing, low shrinkage, resistance to high and low temperatures, aging resistance, and excellent optical properties. However, conventional silicone rubber has low surface energy and weak polarity, resulting in generally poor adhesion to various substrates such as glass, ceramics, and resins. Under harsh operating environments such as humid heat and thermal shock, it is prone to interfacial failures such as delamination and separation, which in turn affects the service life and operational stability of the devices.

[0004] Currently, the industry commonly uses tackifiers added to silicone matrices to improve and enhance the adhesion strength of silicone materials to various substrates. CN109796595A discloses a high-refractive-index silicone tackifier containing phenolic hydroxyl groups, prepared by polymerization of glycidyl ether alkoxysilane, vinyl-containing alkoxysilane, diphenylsilanediol, and 2,2-diallyl bisphenol A as raw materials. The refractive index of the tackifier is around 1.52. However, the applicable substrate range of this tackifier is relatively narrow. It mainly relies on the charge attraction between the phenolic hydroxyl groups and nylon amide groups to achieve good adhesion strength to nylon substrates. However, the adhesion effect of this tackifier on commonly used substrates such as glass, polarizers, and plastics (such as PC and PMMA) in display bonding scenarios has not been fully verified. Furthermore, 2,2-diallyl bisphenol A, as the source of phenolic hydroxyl groups, has a high raw material price, which significantly increases the overall production cost of the tackifier.

[0005] CN105400446A discloses a tackifier suitable for liquid potting compounds for high refractive index LEDs. The preparation process involves first using phenylsiloxanes containing hydrolyzable alkoxy groups, such as phenyltrimethoxysilane and methylphenyldimethoxysilane, as monomers, and polymerizing them to obtain a colorless and transparent polymethylphenyl silicone resin oligomer. Then, this oligomer is reacted with active silane coupling agents such as vinyltrimethoxysilane and γ-glycidoxypropyltrimethoxysilane via transesterification to obtain the target product, with a refractive index ranging from 1.50 to 1.53. However, this invention employs a two-step preparation process, which is relatively cumbersome. Furthermore, the hydrolysis stage requires the use of strong acids such as concentrated hydrochloric acid and concentrated sulfuric acid as catalysts. If the catalyst is not completely removed, it can easily remain in the product, adversely affecting the curing properties, mechanical properties, and storage stability of the silicone rubber.

[0006] CN120888068A discloses an ester-based organosilicon tackifier, its preparation method, and its application. The preparation method includes the following steps: dissolving itaconic acid compounds and hydrogen-containing silicone oil in a solvent, stirring evenly, adding a catalyst, heating to 25-100℃ for reaction, and distilling off the solvent under reduced pressure after the reaction is complete to obtain the ester-based organosilicon tackifier. This tackifier can effectively improve the adhesion performance of addition-type liquid silicone rubber (ALSR) to materials such as polyester fibers, stainless steel sheets, and aluminum sheets. It requires a small amount, has good compatibility with silicone rubber, and the resulting silicone rubber solution is stable with a long shelf life. However, its adhesion enhancement effect on low-polarity or non-polar substrates is limited.

[0007] Therefore, developing a silicone tackifier that is compatible with silicone rubber, has a high refractive index, and possesses excellent adhesive properties and environmental adaptability is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0008] To address the shortcomings of existing technologies, the present invention aims to provide an organosilicon tackifier, its preparation method, and its applications. This invention constructs a high-refractive-index molecular framework using phenylsilanol and combines it with siloxane monomers to create a multifunctional crosslinking system that combines reactivity with excellent adhesive properties. Simultaneously, a small-molecule diol is introduced, embedding organic segments into inorganic silicon segments to form a stable organic-inorganic hybrid structure. This significantly improves the adhesion of silicone rubber to aluminum plates and plastics. The organosilicon tackifier exhibits excellent heat resistance and UV yellowing resistance, meeting the requirements of high-end optical applications.

[0009] To achieve this objective, the present invention adopts the following technical solution: In a first aspect, the present invention provides an organosilicon thickener, wherein the raw materials for preparing the organosilicon thickener include the following components: Phenylsilanol, siloxane monomers, small molecule diols, and catalysts; The siloxane monomers include epoxy siloxane monomers, alkenyl siloxane monomers, dialkoxysilanes, and trialkoxysilanes.

[0010] This invention uses phenylsilanol as the core component. The introduction of phenyl groups increases molecular polarizability and significantly improves the refractive index of the organosilicon tackifier. It also incorporates epoxy siloxane monomers and alkenyl siloxane monomers, whose epoxy and olefin groups exhibit high reactivity, readily reacting with various substrate surfaces to form stable chemical bonds. This improves the adhesion of silicone rubber to different substrates and allows for adjustable refractive index of the organosilicon tackifier. Furthermore, the invention introduces small-molecule diols, embedding flexible organic segments into the inorganic silicon backbone to form a stable organic-inorganic hybrid structure. The inorganic siloxane segments provide high heat resistance, high transparency, and weather resistance, while the organic segments significantly enhance the system's flexibility, interfacial wettability, and adhesive strength, effectively alleviating the problem of low cohesive energy and poor adhesion to non-polar / weakly polar substrates inherent in organosilicon materials. The organosilicon tackifier prepared by the present invention through the compounding of various components has excellent adhesion to polar or non / weakly polar substrates, high light transmittance and refractive index, and good heat resistance and UV yellowing resistance.

[0011] The following are preferred technical solutions of the present invention, but are not intended to limit the technical solutions provided by the present invention. The purpose and beneficial effects of the present invention can be better achieved and realized through the following preferred technical solutions.

[0012] Preferably, the ratio of the total molar amount of hydroxyl groups to the total molar amount of alkoxy groups in the raw materials is (0.8-1.5):1, for example, 0.8:1, 0.9:1, 1.0:1, 1.1:1, 1.2:1, 1.3:1, 1.4:1 or 1.5:1, etc.

[0013] Preferably, the molar ratio of the phenylsilanol to the small molecule diol is 1:(0.8-3.5), such as 1:0.8, 1:1.0, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2.0, 1:2.2, 1:2.4, 1:2.6, 1:2.8, 1:3.0, 1:3.2, 1:3.4, or 1:3.5.

[0014] Preferably, the molar ratio of the epoxysiloxane monomer, the alkenylsiloxane monomer, the dialkoxysilane, and the trialkoxysilane is 1:(0.6-1.0):(1.1-1.7):(0.14-0.34).

[0015] The values ​​for 0.6-1.0 can be 0.6, 0.7, 0.8, 0.9, or 1.0, etc.

[0016] The values ​​for 1.1-1.7 can be 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, or 1.7, etc.

[0017] The values ​​for 0.14-0.34 can be 0.14, 0.16, 0.18, 0.20, 0.22, 0.24, 0.26, 0.28, 0.30, 0.32, or 0.34, etc.

[0018] Preferably, the phenylsilane alcohol comprises any one or a combination of at least two of methylphenylsilanediol, phenylsilanetriol, methylphenylsilanediol, or diphenylsilanediol.

[0019] Preferably, the epoxysiloxane-containing monomer includes any one or a combination of at least two of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltriethoxysilane, γ-(2,3-epoxypropoxy)propylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, or 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane.

[0020] Preferably, the alkenylsiloxane monomer comprises any one or a combination of at least two of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, vinylmethyldimethoxysilane, vinyltriisopropoxysilane, vinyltrichlorosilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane, acryloyloxypropyltrimethoxysilane, or acryloyloxypropylmethyldimethoxysilane.

[0021] Preferably, the dialkoxysilane has R 1 R 2 Si(OR 3 The structure shown in Figure 2, R 1 R 2 R 3 Selected from C1-C5 straight-chain or branched alkyl groups.

[0022] Preferably, the trialkoxysilane has R 4 Si(OR 5 The structure shown in Figure 3, R 4 R 5 Selected from C1-C5 straight-chain or branched alkyl groups.

[0023] Preferably, the C1-C5 straight-chain or branched alkyl group includes any one of methyl, ethyl, propyl, butyl, pentyl, isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, or neopentyl.

[0024] Preferably, the small molecule diol includes any one or a combination of at least two of the following: ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 2-methyl-2,4-pentanediol, 1,4-dihydroxymethylcyclohexane, or 1,4-butynediol, or 1-(2-thiohydroxyethyl)-2-propanol.

[0025] Preferably, the catalyst comprises an alkaline catalyst.

[0026] Preferably, the alkaline catalyst comprises an alkaline anion exchange resin.

[0027] Preferably, the amount of catalyst used is 0.5%-2%, for example, 0.5%, 1%, 1.5% or 2%, based on the total mass of phenylsilanol, siloxane monomer and alcohol compound being 100%.

[0028] In a second aspect, the present invention provides a method for preparing the organosilicon thickener as described in the first aspect, the method comprising the following steps: The organosilicon thickener is obtained by mixing phenylsilanol, siloxane monomer, small molecule diol and catalyst and reacting them.

[0029] Preferably, the reaction temperature is 140-155℃, such as 140℃, 142℃, 144℃, 146℃, 148℃, 150℃, 152℃, 154℃ or 155℃.

[0030] Preferably, the reaction time is 2-3 hours, such as 2 hours, 2.5 hours, or 3 hours.

[0031] Preferably, the reaction is followed by vacuum distillation and filtration.

[0032] Thirdly, the present invention provides the application of the organosilicon thickener as described in the first aspect in a display device.

[0033] Compared with the prior art, the present invention has the following beneficial effects: (1) The present invention uses phenylsilane as the core component, which significantly improves the refractive index of the organosilicon tackifier to 1.54. The refractive index can be adjusted in the range of 1.48-1.58, which can accurately adapt to the refractive index requirements of various optical substrates such as polycarbonate (PC), polymethyl methacrylate (PMMA), and glass. It effectively reduces Fresnel reflection and light loss caused by interface refractive index mismatch, improves the display effect and optical performance of optical components, and has a transmittance ≥98% and haze ≤0.9%.

[0034] (2) The present invention is compounded with epoxy siloxane monomers and alkenyl siloxane monomers. The functional groups contained therein have high reactivity and can react chemically with the surfaces of various substrates to form stable chemical bonds. At the same time, small molecule diols are introduced to form a stable organic-inorganic hybrid structure, which further improves the adhesion performance of silicone rubber to polar and non / weakly polar substrates. The shear strength of silicone rubber to aluminum plate is 3.108-3.245 MPa, and the shear strength of silicone rubber to polycarbonate is 2.102-2.247 MPa.

[0035] (3) This invention adopts a one-pot reaction, which eliminates the need for step-by-step processing and separation of intermediate products. The preparation process is simple, the operating conditions are mild, and the production process is straightforward, which is conducive to industrial-scale production and effective control of production costs, and has good industrialization prospects. At the same time, the catalyst of this invention has high catalytic efficiency, controllable usage, is green and environmentally friendly, non-corrosive, and does not produce harmful by-products. After the reaction, the catalyst can be quickly separated and removed by simple filtration, effectively avoiding the adverse effects of catalyst residue on product performance and subsequent applications, and significantly improving product stability and reliability. Detailed Implementation

[0036] 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.

[0037] The source information of some raw materials in this embodiment of the invention is as follows: Basic anion exchange resin: Anhui Zesheng Technology Co., Ltd., A854519; Vinyl silicone resin: Genesee New Materials Nantong Co., Ltd., Genesee S4; Hydrogen-containing silicone oil: Genasis New Materials Nantong Co., Ltd., CLD 500; Platinum catalyst: Dongguan Dongsheng Synthetic Materials Co., Ltd., DC-5000.

[0038] Example 1 This embodiment provides an organosilicon tackifier, the raw materials for which the organosilicon tackifier is prepared include the following components: Diphenylsilanediol: 86.52g; γ-(2,3-epoxypropoxy)propyltriethoxysilane: 47.27g; Vinylmethyldimethoxysilane: 19.86g; Methyltrimethoxysilane: 5.45g; Dimethyldimethoxysilane: 28.85g; 1,4-Butanediol: 36.05g; Basic anion exchange resin: 2.24g; The preparation method includes the following steps: According to the above formula and dosage, a dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. Diphenylsilanediol, γ-(2,3-epoxypropoxy)propyltriethoxysilane, vinylmethyldimethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, and 1,4-butanediol were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 1.13:1. After stirring evenly at room temperature, the temperature was raised to 95°C, and basic anion exchange resin was added. The mixture was then distilled under normal pressure and heated to 150°C. The mixture was refluxed for 2 hours. Byproducts in the system were removed by vacuum distillation. The product was filtered to remove the basic anion exchange resin, yielding an organosilicon thickener with a yield of 72%. No abnormalities were observed after standing at room temperature for 2 months.

[0039] Example 2 This embodiment provides an organosilicon tackifier, the raw materials for which the organosilicon tackifier is prepared include the following components: Diphenylsilanediol: 32.45g; γ-(2,3-epoxypropoxy)propyltriethoxysilane: 23.64g; Vinylmethyldimethoxysilane: 9.93g; Methyltrimethoxysilane: 2.73g; Dimethyldimethoxysilane: 14.43g; Neopentyl glycol: 26.04g; Basic anion exchange resin: 1.06g; The preparation method includes the following steps: According to the above formula and dosage, a dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. Diphenylsilanediol, γ-(2,3-epoxypropoxy)propyltriethoxysilane, vinylmethyldimethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, and neopentyl glycol were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 1.13:1. After stirring evenly at room temperature, the temperature was raised to 95°C, and basic anion exchange resin was added. The mixture was then distilled under normal pressure and heated to 140°C. The mixture was refluxed for 3 hours. Byproducts in the system were removed by vacuum distillation. The product was filtered to remove the basic anion exchange resin, yielding an organosilicon thickener with a yield of 63%. No abnormalities were observed after standing at room temperature for 2 months.

[0040] Example 3 This embodiment provides an organosilicon tackifier, the raw materials for which the organosilicon tackifier is prepared include the following components: Diphenylsilanediol: 32.45g; γ-(2,3-epoxypropoxy)propyltriethoxysilane: 23.64g; Vinylmethyldimethoxysilane: 9.93g; Methyltrimethoxysilane: 2.18g; Dimethyldimethoxysilane: 15.15g; Neopentyl glycol: 26.04g; Basic anion exchange resin: 1.09g; The preparation method includes the following steps: According to the above formula and dosage, a dry round-bottom flask equipped with a mechanical stirrer, thermometer, and vacuum device was placed in an oil bath. Diphenylsilanediol, γ-(2,3-epoxypropoxy)propyltriethoxysilane, vinylmethyldimethoxysilane, methyltrimethoxysilane, dimethyldimethoxysilane, and neopentyl glycol were added to the round-bottom flask. The molar ratio of hydroxyl to alkoxy groups in the reaction system was 1.14:1. After stirring evenly at room temperature, the temperature was raised to 95°C, and basic anion exchange resin was added. The mixture was then distilled under normal pressure and heated to 155°C. The mixture was refluxed for 2.5 hours. Byproducts in the system were removed by vacuum distillation. The product was filtered to remove the basic anion exchange resin, yielding an organosilicon thickener with a yield of 60%. No abnormalities were observed after standing at room temperature for 2 months.

[0041] Example 4 This embodiment provides an organosilicon tackifier, the raw materials for which the organosilicon tackifier is prepared include the following components: Diphenylsilanediol: 32.45g; γ-(2,3-epoxypropoxy)propyltriethoxysilane: 23.64g; Vinylmethyldimethoxysilane: 9.93g; Methyltrimethoxysilane: 1.63g; Dimethyldimethoxysilane: 15.87g; Neopentyl glycol: 26.04g; Basic anion exchange resin: 1.10g; The molar ratio of hydroxyl to alkoxy groups in the reaction system was 1.14:1. The preparation method was the same as in Example 1, with a yield of 73%. No abnormalities were observed after standing at room temperature for 2 months.

[0042] Example 5 This embodiment provides an organosilicon tackifier, the raw materials for which the organosilicon tackifier is prepared include the following components: Phenylacetic triol: 55.95g; γ-(2,3-epoxypropoxy)propylmethyldimethoxysilane: 18.7g; γ-Methacryloxypropyltrimethoxysilane: 14.88g; Methyltrimethoxysilane: 2.72g; Methylethyldimethoxysilane: 12.72g; 1,2-Propanediol: 19.0g; Basic anion exchange resin: 1.24g; The molar ratio of hydroxyl to alkoxy groups in the reaction system was 1.46:1. The preparation method was the same as in Example 1, with a yield of 70%. No abnormalities were observed after standing at room temperature for 2 months.

[0043] Example 6 This embodiment provides an organosilicon tackifier, the raw materials for which the organosilicon tackifier is prepared include the following components: Methylphenylsilanediol: 32.1g; 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane: 20.91g; Vinyltris(2-methoxyethoxy)silane: 22.4g; Methyltriethoxysilane: 2.35g; Dimethyldimethoxysilane: 14.4g; 1,6-Hexanediol: 29.5g; Basic anion exchange resin: 1.22g; The molar ratio of hydroxyl to alkoxy groups in the reaction system was 1:1. The preparation method was the same as in Example 1, with a yield of 75%. No abnormalities were observed after standing at room temperature for 2 months.

[0044] Example 7 The only difference from Example 1 is that the amount of diphenylsilanediol used is 121.9 g, and the amount of 1,4-butanediol used is 50.8 g (the ratio of the total molar amount of hydroxyl groups to the total molar amount of alkoxy groups is 1.6:1). The amount of other components and the preparation method are the same as in Example 1. The yield is 63%, and a white solid with no flowability is obtained.

[0045] Example 8 The only difference from Example 1 is that the amount of diphenylsilanediol used is 53.4g, and the amount of 1,4-butanediol used is 22.2g (the ratio of the total molar amount of hydroxyl to the total molar amount of alkoxy is 0.7:1). The amount of other components and the preparation method are the same as in Example 1. The yield is 50%, and there are no abnormalities after being placed at room temperature for 2 months.

[0046] Comparative Example 1 The only difference from Example 1 is that in the preparation method, the temperature was raised to 125°C by atmospheric distillation, while the amount of other components and the preparation method were the same as in Example 1. The yield was 70%, and no abnormalities were observed after being placed at room temperature for 2 months.

[0047] Comparative Example 2 The only difference from Example 1 is that diphenylsilanediol is not added, the amount of 1,4-butanediol is 73g (the molar ratio of hydroxyl to alkoxy in the reaction system is 1.13:1), the amount of basic anion exchange resin is 1.74g, and the amounts of other components and the preparation method are the same as in Example 1. The yield is 40%, and there are no abnormalities after being placed at room temperature for 2 months.

[0048] Comparative Example 3 The only difference from Example 1 is that γ-(2,3-epoxypropoxy)propyltriethoxysilane is not added. The amounts of the remaining components are: 32.45 g of diphenylsilanediol, 9.93 g of vinylmethyldialkoxysilane, 14.30 g of methyltrimethoxysilane, 14.43 g of dimethyldimethoxysilane, 26.04 g of neopentyl glycol (the molar ratio of hydroxyl to alkoxy groups in the reaction system is 1.13:1), and 1.06 g of basic anion exchange resin. The amounts of the remaining components and the preparation method are the same as in Example 1. The yield is 53%, and it solidifies at room temperature without flowability.

[0049] Comparative Example 4 The only difference from Example 1 is that 1,4-butanediol is not added, the amount of diphenylsilanediol is 173.04 g (the molar ratio of hydroxyl to alkoxy groups in the reaction system is 1.13:1), the amount of basic anion exchange resin is 2.74 g, and the amount of other components and the preparation method are the same as in Example 1. The yield is 80%, and a white solid with no flowability is obtained.

[0050] Test case 180g of vinyl silicone resin, 15g of hydrogen-containing silicone oil, and 1.0g of platinum catalyst were mixed and stirred until homogeneous to prepare an addition-type liquid silicone rubber base compound. The base compound was divided into 13 equal parts, labeled as Test Examples 1-8, Comparative Test Examples 1-4, and blank sample, respectively. 0.2g of the organosilicon tackifier prepared in Examples 1-8 and Comparative Examples 1-4 were added to each part according to the corresponding relationship, stirred until homogeneous, and placed in a vacuum drying oven for degassing for 30 minutes. Then, the mixture was filled into tensile test strips and cured in an oven at 90℃ for 1 hour and then at 150℃ for 2 hours. The shear strength of each sample was tested using a universal testing machine.

[0051] Performance testing (1) Viscosity: The viscosity of the silicone tackifier was tested according to GB / T2794-1995; (2) Refractive index: The refractive index of the silicone tackifier was tested according to GB / T 6488-2008; (3) Transmittance and haze: The transmittance and haze of the silicone tackifier were tested according to GB / T 2410-2008; (4) Shear strength: The shear strength of addition-cured silicone rubber to the bonding substrate was tested in accordance with GB / T 13936-1992.

[0052] The performance of the silicone tackifiers provided in the examples and comparative examples was tested according to the above performance testing method, and the results are shown in Table 1: Table 1 As shown in Table 1, the organosilicon tackifiers prepared in Examples 1-6 of this invention have high light transmittance (≥98%), low haze (≤0.9%), and a refractive index as high as 1.54, which can be adjusted within the range of 1.48-1.58. This allows them to precisely adapt to the refractive index requirements of various optical substrates such as polycarbonate, polymethyl methacrylate, and glass. The shear strength between silicone rubber and aluminum plate is 3.108-3.245 MPa, and the shear strength between silicone rubber and polycarbonate is 2.102-2.247 MPa, which are significantly improved compared to the blank samples (0.413 MPa and 0.274 MPa, respectively).

[0053] In Example 7, the ratio of the total molar amount of hydroxyl groups to the total molar amount of alkoxy groups was too large, and the content of phenylsilane was too high, resulting in the generated organosilicon tackifier being a white solid that could not be used and could not be used for performance testing. In Example 8, the ratio of the total molar amount of hydroxyl groups to the total molar amount of alkoxy groups was too small, and the low content of phenylsilane resulted in a decrease in the refractive index of the prepared organosilicon tackifier. Furthermore, the decrease in the content of small molecule diols resulted in a decrease in the shear strength to the substrate.

[0054] The reaction temperature of the silicone tackifier prepared in Comparative Example 1 was too low, resulting in incomplete reaction and some impurities remaining in the silicone gel, which led to a significant decrease in the bonding strength between the silicone rubber and the substrate.

[0055] In Comparative Example 2, the raw materials for preparing the organosilicon tackifier lacked phenylsilanol, and the refractive index decreased from 1.54 to 1.42, which weakened the chemical bonding ability between the silicone rubber and the aluminum plate / PC interface and reduced the bonding strength.

[0056] In Comparative Example 3, the lack of alkoxy monomers led to a decrease in the bonding strength between the silicone rubber and the substrate.

[0057] In Comparative Example 4, the lack of small molecule diol resulted in a white solid organosilicon tackifier that was unusable and could not be used for performance testing. The comparison between Example 1 and Comparative Examples 2-4 clearly demonstrates that phenylsilanol, siloxane monomer, and small molecule diol are all indispensable and essential for improving the refractive index or adhesive strength of organosilicon tackifiers.

[0058] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. An organosilicon tackifier, characterized in that, The raw materials for preparing the organosilicon thickener include the following components: Phenylsilanol, siloxane monomers, small molecule diols, and catalysts; The siloxane monomers include epoxy siloxane monomers, alkenyl siloxane monomers, dialkoxysilanes, and trialkoxysilanes.

2. The organosilicon thickener according to claim 1, characterized in that, The ratio of the total molar amount of hydroxyl groups to the total molar amount of alkoxy groups in the raw materials used for preparation is (0.8-1.5):1; Preferably, the molar ratio of the phenylsilanol to the small molecule diol is 1:(0.8-3.5); Preferably, the molar ratio of the epoxysiloxane monomer, the alkenylsiloxane monomer, the dialkoxysilane, and the trialkoxysilane is 1:(0.6-1.0):(1.1-1.7):(0.14-0.34).

3. The organosilicon tackifier according to claim 1 or 2, characterized in that, The phenylsilane alcohol includes any one or a combination of at least two of methylphenylsilanediol, phenylsilanetriol, methylphenylsilanediol, or diphenylsilanediol. Preferably, the epoxysiloxane-containing monomer includes any one or a combination of at least two of γ-(2,3-epoxypropoxy)propyltrimethoxysilane, γ-(2,3-epoxypropoxy)propyltriethoxysilane, γ-(2,3-epoxypropoxy)propylmethyldimethoxysilane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, or 2-(3,4-epoxycyclohexyl)ethyltriethoxysilane. Preferably, the alkenylsiloxane monomer comprises any one or a combination of at least two of vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri(2-methoxyethoxy)silane, vinylmethyldimethoxysilane, vinyltriisopropoxysilane, vinyltrichlorosilane, γ-methacryloyloxypropyltrimethoxysilane, γ-methacryloyloxypropyltriethoxysilane, acryloyloxypropyltrimethoxysilane, or acryloyloxypropylmethyldimethoxysilane.

4. The organosilicon tackifier according to any one of claims 1-3, characterized in that, The dialkoxysilane has R 1 R 2 Si(OR 3 The structure shown in Figure 2, R 1 R 2 R 3 Selected from C1-C5 straight-chain or branched alkyl groups; Preferably, the trialkoxysilane has R 4 Si(OR 5 The structure shown in Figure 3, R 4 R 5 Selected from C1-C5 straight-chain or branched alkyl groups.

5. The organosilicon tackifier according to any one of claims 1-4, characterized in that, The small molecule diols include any one or a combination of at least two of the following: ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,4-butanediol, 1,6-hexanediol, 1,4-cyclohexanediol, neopentyl glycol, 2-methyl-1,3-propanediol, 2-methyl-2,4-pentanediol, 1,4-dihydroxymethylcyclohexane, or 1,4-butynediol, or 1-(2-thiohydroxyethyl)-2-propanol.

6. The organosilicon tackifier according to any one of claims 1-5, characterized in that, The catalyst includes a basic catalyst; Preferably, the alkaline catalyst comprises an alkaline anion exchange resin; Preferably, the amount of catalyst used is 0.5%-2% based on the total mass of phenylsilanol, siloxane monomer and alcohol compound being 100%.

7. A method for preparing the organosilicon tackifier according to any one of claims 1-6, characterized in that, The preparation method includes the following steps: The organosilicon thickener is obtained by mixing phenylsilanol, siloxane monomer, small molecule diol and catalyst and reacting them.

8. The preparation method according to claim 7, characterized in that, The reaction temperature is 140-155℃; Preferably, the reaction time is 2-3 hours.

9. The preparation method according to claim 7 or 8, characterized in that, The reaction is followed by vacuum distillation and filtration.

10. The use of an organosilicon thickener as described in any one of claims 1-6 in a display device.

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