Strong Adhesion Organosilicon Electronic Encapsulant and Its Preparation Method

Abstract

The present invention belongs to the technical field of potting glue, and specifically relates to a strong adhesive organic silicon electronic potting glue and a preparation method thereof. The following raw materials are included: α, ω-dihydroxy polydimethylsiloxane, dimethyl silicone oil, hydroxy silicone oil, methyl triacetoxysilane, ethyl triacetoxysilane, white oil, dibutyltin diacetate, fumed silica and an adhesive; the adhesive is an epoxy acryloxysilane coupling agent, which is prepared by silane coupling reaction of γ-glycidyloxypropyl trimethoxysilane and γ-methacryloxypropyl triisopropoxysilane. The molecular structure of the potting glue has multiple functional groups, which effectively improves the compatibility, reinforcement effect and bonding performance of the potting glue, which can not only meet the demand of modern electronic products for high-performance packaging materials, but also provide strong technical support and guarantee for the development of the electronics industry.

Description

Technical Field

[0001] The invention belongs to the technical field of potting glue, and in particular relates to a strong-adhesion organic silicon electronic potting glue and a preparation method thereof. Background Art

[0002] In the rapidly developing electronics industry, with the widespread application of technologies such as 5G communications, the Internet of Things, and artificial intelligence, the design trend of electronic products is increasingly moving towards high integration, multifunctionality, lightweight, and adaptability to extreme environments. This trend poses unprecedented challenges to the packaging and protection materials of electronic components. As one of the key packaging materials, the performance of electronic potting glue directly affects the overall performance, reliability, and service life of electronic products. Traditional electronic potting glue mainly relies on materials such as epoxy resin, polyurethane, and silicone as the matrix, supplemented by various fillers and additives to improve its performance. However, these traditional materials are unable to cope with the high requirements of modern electronic products. For example, in extreme environments such as high temperature, high humidity, and strong corrosion, the bonding strength of traditional potting glue will decrease significantly, resulting in the failure of the sealing of electronic components, which in turn causes safety problems such as short circuits and leakage. In addition, traditional potting glue may produce a large shrinkage rate during the curing process, resulting in microcracks between the packaging layer and the electronic components, further reducing the reliability of the product.

[0003] In order to overcome the above-mentioned defects of traditional potting glue, researchers began to turn their attention to the development and application of new adhesives. New adhesives usually have unique molecular structures and chemical properties, and can show excellent bonding performance, temperature resistance, chemical corrosion resistance and low shrinkage under different conditions. These characteristics make new adhesives an ideal choice for improving the performance of electronic potting glue. At present, a variety of new adhesives have been successfully used in electronic potting glue, such as modified epoxy resin, high-performance silicone, nanocomposites, etc. These new adhesives not only significantly improve the bonding strength and stability of potting glue, but also give potting glue more functional properties, such as thermal conductivity, flame retardancy, electromagnetic shielding, etc. However, although the application of new adhesives in electronic potting glue has made certain progress, the market is still seeking a potting glue that can better meet the diversified high-performance requirements of modern electronic products to further optimize and improve the existing packaging material selection. Summary of the invention

[0004] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a highly adhesive silicone electronic potting glue, which has multiple functional groups in its molecular structure, effectively improving the compatibility, reinforcement effect and bonding performance of the potting glue, which can not only meet the needs of modern electronic products for high-performance packaging materials, but also provide strong technical support and guarantee for the development of the electronics industry.

[0005] Another object of the present invention is to provide a method for preparing a strong adhesive organic silicon electronic potting glue, which is scientific, reasonable, simple and easy to implement.

[0006] The technical solution adopted by the present invention is as follows:

[0007] The highly adhesive organic silicon electronic potting adhesive comprises the following raw materials in parts by weight:

[0008] α,ω-dihydroxypolydimethylsiloxane: 90-110 parts;

[0009] Dimethyl silicone oil: 7-9 parts;

[0010] Hydroxy silicone oil: 1.8~3 parts;

[0011] Methyltriacetoxysilane: 2-4 parts;

[0012] Ethyl triacetoxysilane: 2-5 parts;

[0013] White oil: 1~3 parts;

[0014] Dibutyltin diacetate: 0.05~0.2 parts;

[0015] Fumed silica: 15-25 parts;

[0016] Adhesive: 1~4 parts;

[0017] The adhesive is an epoxy acryloxy silane coupling agent, which is prepared by silane coupling reaction of γ-glycidyloxypropyl trimethoxy silane (KH-560) and γ-methacryloxypropyl triisopropoxy silane.

[0018] The epoxy acryloxy silane coupling agent comprises the following raw materials in parts by weight:

[0019] γ-Glycidyloxypropyltrimethoxysilane (KH-560): 50~60 parts;

[0020] γ-Methacryloxypropyltriisopropoxysilane: 90-110 parts;

[0021] Ethyl orthosilicate: 1-2 parts;

[0022] Ethanol: 2~3 parts;

[0023] Deionized water: 6~8 parts.

[0024] The preparation method of the epoxy acryloxy silane coupling agent is:

[0025] TEOS, ethanol and deionized water are mixed to obtain a precursor solution, γ-glycidyloxypropyltrimethoxysilane and γ-methacryloxypropyltriisopropoxysilane are mixed, and then added to the precursor solution for reaction. After the reaction is completed, an epoxy acryloxysilane coupling agent is obtained, and the reaction formula is as follows:

[0026] .

[0027] The reaction conditions are: first react at room temperature for 2-2.5 hours, then heat to 80-85°C, and continue to react for 1-1.5 hours.

[0028] The viscosity of the α,ω-dihydroxy polydimethylsiloxane is 18000-22000 mPa·s.

[0029] The viscosity of the dimethyl silicone oil is 320-350 mPa·s.

[0030] The specific surface area of ​​the fumed silica is 290-310 m 2 / g.

[0031] The purity of the γ-glycidyloxypropyltrimethoxysilane (KH-560) is ≥98%; the purity of the γ-methacryloxypropyltriisopropoxysilane is ≥98%.

[0032] The white oil is No. 3 white oil.

[0033] The purity of the methyltriacetoxysilane is ≥90%; the purity of the ethyltriacetoxysilane is ≥95%; and the purity of the dibutyltin diacetate is ≥33%.

[0034] The method for preparing the highly adhesive organosilicon electronic potting adhesive comprises the following steps:

[0035] (1) Add α,ω-dihydroxy polydimethylsiloxane to a kneader, then add fumed silica and hydroxy silicone oil in portions, knead evenly, raise the temperature to 120°C, and evacuate for 1 hour at a vacuum degree of 0.1 MPa to obtain a base rubber compound;

[0036] (2) Control the material temperature to less than 35°C, add the base rubber and dimethyl silicone oil into a planetary mixer, vacuum stir for 1 to 2 hours until it becomes dilute, then add methyl triacetoxysilane, ethyl triacetoxysilane, and epoxy acryloxy silane coupling agent, vacuum stir for 2 to 3 hours until it becomes dilute, then add dibutyl tin diacetate and white oil, and vacuum stir for 0.75 to 1 hour for the third time to obtain a strong adhesion silicone electronic potting glue.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The present invention achieves multiple functional optimization by preparing an adhesive that combines methoxy, isopropoxy, epoxy and methacryloxy groups. Specifically, Figure 2 As shown in the figure, the methoxy and isopropoxy groups not only participate in the condensation reaction, but also effectively modify the surface of fumed silica through the hydrolysis condensation pathway, significantly weakening the large-scale agglomeration of silica and significantly enhancing its compatibility with α,ω-dihydroxy polydimethylsiloxane. During the curing process of the potting compound, the epoxy group and the methacryloyloxy group can migrate to the surface of the base material, react physically or chemically with the organic base, generate a strong interaction force, and greatly improve the bonding performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is a Fourier transform infrared spectrum of the strong adhesion organic silicon electronic potting glue prepared in Example 4;

[0040] Figure 2 Schematic diagram of the interaction between strong adhesion silicone electronic potting adhesive and substrate. DETAILED DESCRIPTION

[0041] The present invention is further described below with reference to the embodiments, but they do not limit the implementation of the present invention.

[0042] The raw materials used in the examples and comparative examples are conventional commercially available raw materials unless otherwise specified, and the process methods used in the examples and comparative examples are conventional methods in the art unless otherwise specified.

[0043] Some of the raw materials used in the examples and comparative examples are described as follows:

[0044] α,ω-dihydroxypolydimethylsiloxane, purchased from Shandong Dongyue Silicone Materials Co., Ltd., with a viscosity of 20000±2000 mPa·s;

[0045] Dimethyl silicone oil, purchased from Shandong Dongyue Silicone Materials Co., Ltd., with a viscosity of 335 ± 15 mPa·s;

[0046] Fumed silica, purchased from Shandong Dongyue Organic Silicon Materials Co., Ltd., with a specific surface area of ​​300 ± 10 m 2 / g;

[0047] γ-Methacryloxypropyltriisopropoxysilane and γ-glycidyloxypropyltrimethoxysilane were purchased from Jiangsu Chenguang Coupling Agent Co., Ltd.;

[0048] The preparation method of the epoxy acryloxy silane coupling agent is:

[0049] 30g of deionized water, 10g of anhydrous ethanol and 5.5g of tetraethyl orthosilicate were mixed and dispersed uniformly at room temperature with a magnetic stirrer to obtain a precursor solution. In a three-necked flask equipped with a condenser and a thermometer, 55g of KH-560 and 100g of γ-methacryloxypropyltriisopropoxysilane (molar ratio of 1:1) were added. After mixing uniformly under the protection of nitrogen, 10g of the precursor solution was slowly added dropwise. The temperature was controlled at 25°C. After the addition was completed, magnetic stirring was performed for 2h, and then the temperature was raised to 82.5±2.5°C. The reaction was continued for 1h. After the solvent was evaporated under reduced pressure, the epoxy acryloxy silane coupling agent was obtained.

[0050] Example 1

[0051] The highly adhesive organic silicon electronic potting adhesive comprises the following raw materials in parts by weight:

[0052] α,ω-dihydroxypolydimethylsiloxane: 90 parts;

[0053] Dimethicone oil: 7 parts;

[0054] Hydroxy silicone oil: 1.8 parts;

[0055] Methyltriacetoxysilane: 2 parts;

[0056] Ethyl triacetoxysilane: 2 parts;

[0057] No. 3 white oil: 1 part;

[0058] Dibutyltin diacetate: 0.05 parts;

[0059] Fumed silica: 15 parts;

[0060] Epoxy acryloxy silane coupling agent: 1 part.

[0061] The method for preparing the highly adhesive organosilicon electronic potting adhesive comprises the following steps:

[0062] (1) Add α,ω-dihydroxy polydimethylsiloxane to a kneader, then add fumed silica and hydroxy silicone oil in portions, knead evenly, raise the temperature to 120°C, and evacuate for 1 hour at a vacuum degree of 0.1 MPa to obtain a base rubber compound;

[0063] (2) Control the material temperature to less than 35°C, add the base rubber and dimethyl silicone oil into a planetary mixer, vacuum stir for 1.5 hours until it becomes dilute, then add methyl triacetoxysilane, ethyl triacetoxysilane, and epoxy acryloxy silane coupling agent, vacuum stir for 2.5 hours until it becomes dilute, then add dibutyl tin diacetate and No. 3 white oil, and vacuum stir for the third time for 0.75 hours to obtain a strong adhesion silicone electronic potting glue.

[0064] Example 2

[0065] The highly adhesive organic silicon electronic potting adhesive comprises the following raw materials in parts by weight:

[0066] α,ω-dihydroxypolydimethylsiloxane: 90 parts;

[0067] Dimethicone oil: 7 parts;

[0068] Hydroxy silicone oil: 1.8 parts;

[0069] Methyltriacetoxysilane: 2 parts;

[0070] Ethyl triacetoxysilane: 2 parts;

[0071] No. 3 white oil: 1 part;

[0072] Dibutyltin diacetate: 0.05 parts;

[0073] Fumed silica: 15 parts;

[0074] Epoxy acryloxy silane coupling agent: 2.5 parts.

[0075] The preparation method of the highly adhesive organosilicon electronic potting adhesive has the same steps as those of Example 1.

[0076] Example 3

[0077] The highly adhesive organic silicon electronic potting adhesive comprises the following raw materials in parts by weight:

[0078] α,ω-dihydroxypolydimethylsiloxane: 90 parts;

[0079] Dimethicone oil: 7 parts;

[0080] Hydroxy silicone oil: 1.8 parts;

[0081] Methyltriacetoxysilane: 2 parts;

[0082] Ethyl triacetoxysilane: 2 parts;

[0083] No. 3 white oil: 1 part;

[0084] Dibutyltin diacetate: 0.05 parts;

[0085] Fumed silica: 15 parts;

[0086] Epoxy acryloxy silane coupling agent: 4 parts.

[0087] The preparation method of the highly adhesive organosilicon electronic potting adhesive has the same steps as those of Example 1.

[0088] Example 4

[0089] The highly adhesive organic silicon electronic potting adhesive comprises the following raw materials in parts by weight:

[0090] α,ω-dihydroxy polydimethylsiloxane: 110 parts;

[0091] Dimethicone oil: 9 parts;

[0092] Hydroxy silicone oil: 3 parts;

[0093] Methyltriacetoxysilane: 4 parts;

[0094] Ethyl triacetoxysilane: 5 parts;

[0095] No. 3 white oil: 3 parts;

[0096] Dibutyltin diacetate: 0.2 parts;

[0097] Fumed silica: 25 parts;

[0098] Epoxy acryloxy silane coupling agent: 4 parts.

[0099] The preparation method of the highly adhesive organosilicon electronic potting adhesive has the same steps as those of Example 1.

[0100] Fourier transform infrared spectroscopy was used to analyze the γ-glycidyloxypropyl trimethoxysilane, γ-methacryloxypropyl triisopropoxysilane, epoxy acryloxy silane coupling agent used in Example 4 and the strong adhesion organic silicon electronic potting glue prepared in Example 4. The test results are as follows: Figure 1 As shown. 1707, 1630cm -1 These are the characteristic absorption peaks of C=O and C=C on γ-methacryloxypropyltriisopropoxysilane. 1075cm -1 The peak at 1075cm is the anti-stretching vibration peak of Si-O-Si. With the completion of the synthesis process of the adhesive epoxy acryloxy silane coupling agent under the catalysis of ethyl orthosilicate precursor solution, γ-glycidyloxypropyl trimethoxysilane and γ-methacryloxypropyl triisopropoxysilane are synthesized. -1 The characteristic peak at the position changed from the weak peaks of γ-glycidyloxypropyltrimethoxysilane and γ-methacryloxypropyltriisopropoxysilane to the strong peak of epoxy acryloxysilane coupling agent.

[0101] Comparative Example 1

[0102] The difference from Example 4 is that the added amount of the adhesive epoxy acryloxy silane coupling agent is 0 parts, and the rest is the same as Example 4.

[0103] Comparative Example 2

[0104] The difference from Example 4 is that an equal amount of γ-glycidyloxypropyltrimethoxysilane is used to replace the epoxy acryloxy silane coupling agent, and the rest is the same as Example 4.

[0105] Comparative Example 3

[0106] The difference from Example 4 is that an equal amount of γ-methacryloxypropyltriisopropoxysilane is used to replace the epoxyacryloxysilane coupling agent, and the rest is the same as Example 4.

[0107] Comparative Example 4

[0108] The difference from Example 4 is that 2 parts of γ-glycidyloxypropyltrimethoxysilane and 2 parts of γ-methacryloxypropyltriisopropoxysilane are added to replace the epoxyacryloxysilane coupling agent, and the rest is the same as Example 4.

[0109] The potting glue prepared in Examples 1 to 4 and Comparative Examples 1 to 4 was tested for performance, PVC was selected as the substrate, and the test size was 10 cm 3 After curing the strip (10cm×1cm×1cm) at room temperature, it was transferred to 85℃ / 85% humidity environment for further curing for 24 hours and then its performance was tested. The test method is as follows:

[0110] Tensile strength (MPa): Tested in accordance with GB / T 528-2009;

[0111] Elongation at break (%): Tested in accordance with GB / T 528-2009;

[0112] Single lap tensile shear strength (MPa): tested in accordance with GB / T 33334-2016;

[0113] 90° peel strength (MPa): Tested in accordance with GB / T2792-2014;

[0114] Surface drying time (s): Tested in accordance with GB / T 13477.5-2002;

[0115] Viscosity (mPa·s): Tested in accordance with GB / T 265-2004;

[0116] The addition amount of each component in the embodiments and comparative examples is shown in Table 1.

[0117] Table 1 Addition amount of each component in the examples and comparative examples

[0118]

[0119] The test results are shown in Table 2.

[0120] Table 2 Performance test results

[0121]

[0122] It can be seen from Table 1 that the potting glue prepared in the embodiment gradually improves the tensile strength, elongation, single lap tensile shear strength and 90° peel strength of the glue strip on the PVC substrate due to the continuous increase in the amount of the added adhesive epoxy acryloxy silane coupling agent and fumed silica.

[0123] Compared with Example 4, Comparative Example 1 lacks the effect of the adhesive epoxy acryloxy silane coupling agent, resulting in a significant reduction in the single lap tensile shear strength, 90° peel strength and tensile strength of the adhesive strip on the PVC substrate.

[0124] Compared with Example 4, Comparative Examples 2 and 3 use only γ-glycidyloxypropyltrimethoxysilane or γ-methacryloxypropyltriisopropoxysilane instead of epoxyacryloxysilane coupling agent as adhesive, resulting in significantly lower bonding performance than Example 4.

[0125] Compared with Example 4, Comparative Example 4 simply physically mixes γ-glycidyloxypropyltrimethoxysilane and γ-methacryloxypropyltriisopropoxysilane, resulting in poor bonding effect of the prepared potting glue, and its bonding strength is still lower than the bonding strength of the potting glue prepared by using epoxy acryloxy silane coupling agent.

Claims

1. A strong adhesive silicone electronic potting glue, characterized in that: The invention comprises the following raw materials in parts by weight: α,ω-dihydroxypolydimethylsiloxane: 90-110 parts; Dimethyl silicone oil: 7-9 parts; Hydroxy silicone oil: 1.8~3 parts; Methyltriacetoxysilane: 2-4 parts; Ethyl triacetoxysilane: 2-5 parts; White oil: 1~3 parts; Dibutyltin diacetate: 0.05~0.2 parts; Fumed silica: 15-25 parts; Adhesive: 1~4 parts; The adhesive is an epoxy acryloxy silane coupling agent, which includes the following raw materials in parts by weight: γ-Glycidyloxypropyltrimethoxysilane: 50-60 parts; γ-Methacryloxypropyltriisopropoxysilane: 90-110 parts; Ethyl orthosilicate: 1-2 parts; Ethanol: 2~3 parts; Deionized water: 6~8 parts.

2. The strong adhesive organic silicon electronic potting adhesive according to claim 1, characterized in that: The preparation method of the epoxy acryloxy silane coupling agent is: TEOS, ethanol and deionized water are mixed to obtain a precursor solution, γ-glycidyloxypropyltrimethoxysilane and γ-methacryloxypropyltriisopropoxysilane are mixed, and then added to the precursor solution for reaction, and an epoxy acryloxysilane coupling agent is obtained after the reaction is completed.

3. The strong adhesive organic silicon electronic potting adhesive according to claim 2, characterized in that: The reaction conditions are: first react at room temperature for 2-2.5 hours, then heat to 80-85°C, and continue to react for 1-1.5 hours.

4. The strong adhesive organic silicon electronic potting adhesive according to claim 1, characterized in that: The viscosity of the α,ω-dihydroxy polydimethylsiloxane is 18000-22000 mPa·s.

5. The strong adhesive organic silicon electronic potting adhesive according to claim 1, characterized in that: The viscosity of the dimethyl silicone oil is 320-350 mPa·s.

6. The strong adhesive organic silicon electronic potting adhesive according to claim 1, characterized in that: The white oil is No. 3 white oil.

7. The strong adhesive organic silicon electronic potting adhesive according to claim 1, characterized in that: The specific surface area of ​​the fumed silica is 290-310 m 2 / g.

8. A method for preparing the strong adhesive organic silicon electronic potting adhesive according to any one of claims 1 to 7, characterized in that: The following steps are involved: (1) adding α,ω-dihydroxy polydimethylsiloxane into a kneader, and then adding fumed silica and hydroxy silicone oil, kneading evenly to obtain a base rubber compound; (2) Add the base rubber and dimethyl silicone oil into a planetary mixer. After the first vacuum stirring, add methyl triacetoxysilane, ethyl triacetoxysilane, and epoxy acryloxy silane coupling agent. After the second vacuum stirring, add dibutyl tin diacetate and white oil. After the third vacuum stirring, a strong adhesion silicone electronic potting glue is obtained.

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