A phenolic modified silicone oil, a preparation method and applications thereof
By introducing highly reactive alcohol hydroxyl terminus and side-chain phenol groups into phenol-modified silicone oil and forming a cross-linking network with modified chitosan, the problem of phenol-modified silicone oil being difficult to chemically bond with the polymer matrix under mild conditions is solved, thereby improving the hydrophobicity, oxidation resistance and mechanical strength of the material.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HANGZHOU TOP WIN TECH DEV CO LTD
- Filing Date
- 2025-10-22
- Publication Date
- 2026-07-21
AI Technical Summary
Phenolic modified silicone oils are difficult to achieve efficient chemical bonding with polymer matrices under mild conditions, which leads to their easy migration and precipitation in electronic component packaging, affecting the durability and stability of hydrophobic and antioxidant properties.
By introducing highly reactive alcohol hydroxyl terminus and side-chain phenol groups into phenol-modified silicone oil, chemically bonding them to the polymer matrix via hydrosilylation reaction, and combining them with modified chitosan to form a dense cross-linked network, the compatibility and stability of the material are enhanced.
It improves the grafting rate and compatibility of phenol-modified silicone oil with the polymer matrix, enhances the hydrophobicity, resistance to humid heat aging and oxidation resistance of polyurethane electronic packaging materials, and compensates for the loss of mechanical strength caused by the introduction of siloxane segments.
Smart Images
Figure SMS_1
Abstract
Description
Technical Field
[0001] This application relates to the field of polysiloxane materials, and in particular to a phenol-modified silicone oil, its preparation method, and its application. Background Technology
[0002] Phenolic modified silicone oils combine the flexibility of polysiloxane backbones, low surface energy, and the polarity of phenolic hydroxyl groups, exhibiting comprehensive advantages such as high-temperature resistance, oxidation resistance, low surface tension, and good electrical insulation. These properties make them widely used in many fields, especially in coating materials and electronic packaging materials where high durability and stability are required, where they are considered a highly promising modifying agent. By introducing phenolic silicone oils into polymer matrices, the hydrophobicity, migration resistance, and heat oxidation resistance of the substrate can be significantly improved, thereby extending the service life of the products.
[0003] However, although phenol-modified silicone oils have improved compatibility with matrix materials compared to traditional non-polar silicone oils, the reactivity of phenolic hydroxyl groups is relatively limited. When blending or reacting with matrix materials, they often require harsh external conditions such as high temperature, high pressure, or strong catalysis to initiate effective chemical bonding. This increases the difficulty of process control and energy consumption costs, and also poses risks in temperature-sensitive applications such as electronic component packaging. More importantly, under mild conditions, phenol-modified silicone oils struggle to achieve high grafting efficiency. Most silicone oil molecules are only physically dispersed in the matrix, failing to form strong chemical bonds with the matrix. This physical dispersion state easily leads to the migration and precipitation of silicone oil molecules under long-term use or external environmental stress, making it difficult to maintain and stably exert their hydrophobic and antioxidant properties. Summary of the Invention
[0004] To improve the reactivity of phenol-modified silicone oil, achieve good chemical bonding with the polymer matrix, and thus enhance the hydrophobicity and antioxidant capacity of the material, this application provides a phenol-modified silicone oil, its preparation method, and its application.
[0005] In a first aspect, this application provides a phenol-modified silicone oil comprising a hydrogen-terminated silicone oil, a hydroxy acrylate, a tetramethylcyclotetrasiloxane, and an enylphenol in a molar ratio of 1:2.1–2.3:3–5:3.3–6.5, wherein the hydrogen-terminated silicone oil and the hydroxy acrylate are hydrosilylated to obtain a hydroxyl silicone oil; the hydroxyl silicone oil and the tetramethylcyclotetrasiloxane are ring-opening polymerized to obtain a side-hydrogen-modified hydroxyl silicone oil; the side-hydrogen-modified hydroxyl silicone oil is then hydrosilylated with an enylphenol to obtain a phenol-modified silicone oil.
[0006] In any of the above technical solutions, the phenol is selected from any one or more of 2-vinylphenol, 4-vinylphenol, 2-allylphenol, 4-allylphenol, 2-methoxy-4-allylphenol, 2-methoxy-4-vinylphenol, and 2,6-dimethoxy-4-allylphenol.
[0007] In any of the above technical solutions, the hydroxy acrylate is selected from any one or more of hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, 4-hydroxybutyl acrylate, and N-hydroxymethylacrylamide.
[0008] In the preparation process of the phenol-modified silicone oil of this application, firstly, the Si-H bonds at both ends of the hydrogen-terminated silicone oil are used to undergo hydrosilylation with hydroxyl acrylate, thereby introducing highly reactive primary or secondary hydroxyl groups at both ends of the silicone oil chain. Then, the silicone oil with these hydroxyl-terminated ends is used as an initiator to undergo ring-opening polymerization with tetramethylcyclotetrasiloxane, thereby introducing new Si-H bonds at the side positions of the siloxane backbone. Finally, these side chain Si-H bonds are then hydrosilylated with phenol to graft phenol groups onto the side chains of the silicone oil. This structure has two advantages. First, the terminal alcohol hydroxyl groups have higher reactivity than phenolic hydroxyl groups, especially in the reaction with isocyanates, which ensures that the modified silicone oil can preferentially and efficiently embed into polymer networks such as polyurethane through chemical bonding, solving the migration problem caused by physical blending and significantly improving the grafting rate. Second, the phenolic groups introduced into the side chain not only have the ability to participate in the reaction, but also further enhance the compatibility with the polar polymer matrix. More importantly, they endow the material with excellent heat and oxidation stability, which improves the anti-aging performance of the final composite material.
[0009] In any of the above technical solutions, the hydrogen content of the end-hydrogen silicone oil is 0.1-0.2%.
[0010] Placing highly reactive alcohol hydroxyl groups at the ends of molecular chains helps to improve the reactivity of the alcohol hydroxyl groups and increase the grafting rate of modified phenolic silicone oils. Specifically, during polymer chain growth, the functional groups at the chain ends have the highest mobility and the lowest steric hindrance, making them easier to contact and react with the functional groups of the matrix material, thereby maximizing grafting efficiency. Therefore, if the molecular weight of the phenolic modified silicone oil is too large (i.e., the hydrogen content of the terminal hydrogen-containing silicone oil is too low), although it may improve hydrophobicity, the excessively long chain segments will reduce the functional group density of the terminal hydroxyl groups and increase the entanglement and steric hindrance of the molecular chains, which will hinder its effective bonding with the matrix and lead to a decrease in grafting ability. Therefore, controlling the hydrogen content of the terminal hydrogen-containing silicone oil to 0.1%–0.2% can balance reactivity and modification effect.
[0011] Secondly, a method for preparing a phenol-modified silicone oil includes: According to the raw material ratio of any of the phenol-modified silicone oils described in the first aspect, hydrogen-terminated silicone oil and hydroxy acrylate are mixed evenly, heated to 80-95°C under nitrogen protection, and a platinum catalyst is added to carry out hydrosilylation to obtain hydroxy silicone oil. Hydroxy silicone oil was mixed with cyclotetrasiloxane, an alkaline catalyst was added, and the mixture was heated to 100-120°C under nitrogen protection to carry out ring-opening polymerization, thereby obtaining hydrogen-modified hydroxy silicone oil. Hydrogen-modified hydroxyl silicone oil was mixed with allyl phenol, heated to 85–95°C under nitrogen protection, and hydrosilylation was carried out with a platinum catalyst to obtain phenol-modified silicone oil.
[0012] In any of the above technical solutions, in the hydrosilylation reaction of hydrogen-terminated silicone oil and hydroxy acrylate, the amount of platinum catalyst used is 15-25 ppm (based on Pt content) of the total mass of the reaction system; the reaction time is 4-8 h.
[0013] In any of the above technical solutions, the alkaline catalyst is tetramethylammonium hydroxide.
[0014] In any of the above technical solutions, the amount of alkaline catalyst used is 50 to 200 ppm of the total mass of hydroxyl silicone oil and cyclotetrasiloxane.
[0015] In any of the above technical solutions, the reaction time for the ring-opening polymerization is 3 to 6 hours.
[0016] In any of the above technical solutions, after the ring-opening polymerization reaction is completed, the system is heated to 120-130°C and kept at that temperature for 1-2 hours to decompose the alkaline catalyst.
[0017] In any of the above technical solutions, in the hydrosilylation reaction of hydrogen-modified hydroxyl silicone oil and allyl phenol, the amount of platinum catalyst is 20-30 ppm (based on Pt content) of the total mass of the reaction system; the reaction time is 5-8 h.
[0018] Thirdly, this application provides an application of phenol-modified silicone oil, wherein the phenol-modified silicone oil described in any of the first aspects or the phenol-modified silicone oil obtained in the second aspect is used in polyurethane electronic packaging materials.
[0019] In any of the above technical solutions, the polyurethane electronic packaging material includes a polyurethane prepolymer, the raw materials of which include polyisocyanate, polyol, and phenol-modified silicone oil, and the molar ratio of isocyanate groups in the polyisocyanate, alcohol hydroxyl groups in the polyol, and phenol-modified silicone oil is 1.3-1.6:1:0.05-0.15.
[0020] Polyurethane materials possess excellent flexibility, impact resistance, and bonding properties, making them suitable for use as electronic packaging materials to buffer stress and protect core components. However, traditional polyurethanes exhibit poor hydrolysis resistance in their soft segments (polyether and polyester segments), making them prone to hydrolytic degradation under high temperature and humidity conditions, leading to cracking, powdering, or even failure of the encapsulation. This application incorporates phenol-modified silicone oil as a third component in the synthesis of the polyurethane prepolymer. Through the reaction of the terminal hydroxyl groups of the silicone oil with isocyanate, hydrophobic, flexible, and hydrolysis-resistant polysiloxane segments are firmly introduced into the polyurethane backbone via chemical bonds, constructing hydrophobic segments within the polymer network and significantly improving the encapsulant's resistance to damp heat. Simultaneously, the phenolic groups on the side chains not only contribute to antioxidant effects, but some of their phenolic hydroxyl groups can also participate in the reaction or form strong hydrogen bonds, further enhancing the density and stability of the crosslinked network.
[0021] In any of the above technical solutions, the polyurethane electronic packaging material comprises 100 parts of polyurethane prepolymer, 5-15 parts of filler, 1.5-3.5 parts of modified chitosan, and 0.5-1.5 parts of catalyst; the modified chitosan is prepared by a Schiff base reaction of chitosan, dialdehyde crosslinking agent, and aminoimidazole in a mass ratio of 1:0.2-0.3:0.15-0.25.
[0022] It is worth noting that the introduction of soft siloxane segments will further weaken the modulus, strength, and deformation resistance of polyurethane materials with poor hardness. This application introduces modified chitosan into the polyurethane encapsulation material, which can effectively compensate for the loss of deformation resistance. The abundant hydroxyl and amino groups on the chitosan molecular backbone can serve as additional crosslinking points, participating in and reacting with the curing of polyurethane to form a denser three-dimensional network. This directly helps to compensate for the mechanical strength that may be lost due to the introduction of siloxanes, improving the material's hardness and deformation resistance. More importantly, the aminoimidazolium groups grafted onto chitosan via the Schiff base reaction can form strong ion-dipole interactions and coordination bonds with the lone pair electrons on their nitrogen atoms and polar groups such as carbonyl groups in the polyurethane segments. This constructs a "complex network" in the polyurethane matrix, improving the cohesion and viscoelasticity of the encapsulation material. The final encapsulation material not only maintains excellent flexibility and resistance to damp heat but also possesses good rigidity, impact resistance, and deformation resistance.
[0023] In any of the above technical solutions, the dialdehyde crosslinking agent is glutaraldehyde.
[0024] In any of the above technical solutions, the degree of deacetylation of the chitosan is ≥85%.
[0025] In any of the above technical solutions, the polyol is a polyether triol and a polyether diol with a molar ratio of 2 to 3:1.
[0026] In any of the above technical solutions, the catalyst is selected from any one or more of organotin catalysts, amine catalysts, metal chelates, and imidazole compounds.
[0027] For example, the organotin catalyst is selected from dibutyltin dilaurate, stannous octoate, or dibutyltin diacetate.
[0028] For example, the amine catalyst is selected from triethylenediamine, N,N-dimethylcyclohexylamine, or N,N-dimethylaniline.
[0029] For example, the metal chelate is selected from titanium acetylacetonate or aluminum acetylacetonate.
[0030] In any of the above technical solutions, one or more of the following can be added to the polyurethane electronic packaging material: defoamer, leveling agent, antioxidant, and chain extender.
[0031] In summary, this application has the following beneficial effects: This application synthesizes a phenol-modified silicone oil that combines high reactivity with excellent stability. The silicone oil's terminal hydroxyl groups ensure efficient chemical bonding with the polyurethane matrix, resolving compatibility and grafting rate issues. Simultaneously, the phenolic groups in its side chains contribute durable antioxidant properties. Applying this modified silicone oil to polyurethane electronic packaging materials, and copolymerizing it with isocyanates and polyols to prepare prepolymers, significantly enhances the hydrophobicity and resistance to humid heat aging of the encapsulant. Furthermore, the introduction of modified chitosan additives, through dense hydrogen bonding and coordination, effectively compensates for the potential loss of mechanical properties due to the introduction of siloxane segments, improving cohesion and thus enhancing the hardness and deformation resistance of the packaging material. Detailed Implementation
[0032] Preparation Example Preparation Example 1: Modified chitosan. The preparation steps are as follows: 100g of chitosan powder (85% deacetylation, MW=15000) was added to a reactor, along with 2.5L of 1% (w / w) acetic acid aqueous solution. The mixture was stirred at 300rpm at 25℃ until completely dissolved, yielding a homogeneous and transparent chitosan solution. 20g of 4-aminoimidazole was dissolved in 200mL of deionized water and slowly added to the chitosan solution with stirring until homogeneous. Then, under ice-water bath cooling and continuous stirring, a solution prepared from 25.5g of glutaraldehyde and 200mL of deionized water was slowly added dropwise over 30min. After the addition was complete, the reaction system was heated to 45℃ and reacted for 6 hours under nitrogen protection. After the reaction, the resulting viscous product was poured into 10L of anhydrous ethanol for precipitation. The precipitate was collected by filtration and washed three times each with an ethanol-water mixture (4:1 volume ratio) and pure ethanol. Finally, the product was vacuum dried at 50°C for 24 hours and then pulverized to obtain modified chitosan powder.
[0033] Preparation Example 2, modified chitosan, the preparation steps are as follows: 100g of chitosan powder (85% deacetylation, MW=15000) was added to a reactor, along with 2.0L of a 1% (w / w) aqueous acetic acid solution. The mixture was stirred at 300 rpm at 30°C until completely dissolved, yielding a homogeneous and transparent chitosan solution. 15.5g of 4-aminoimidazole was dissolved in 200mL of deionized water and slowly added to the chitosan solution with stirring until homogeneous. Subsequently, under ice-water bath cooling and continuous stirring, a solution prepared from 21.2g of glutaraldehyde and 200mL of deionized water was slowly added dropwise over 30 minutes. After the addition was complete, the reaction system was heated to 40°C and reacted under nitrogen protection for 6 hours. After the reaction was completed, the resulting viscous product was poured into 10L of anhydrous ethanol for precipitation. The precipitate was collected by filtration and washed three times each with an ethanol-water mixture (volume ratio 4:1) and pure ethanol. Finally, the product was vacuum dried at 50°C for 24 hours and then pulverized to obtain modified chitosan powder.
[0034] Preparation Example 3, modified chitosan, the preparation steps are as follows: 100g of chitosan powder (90% deacetylation, MW=20000) was added to a reactor, along with 3.0L of 1% (w / w) aqueous acetic acid solution. The mixture was stirred at 300rpm at 35℃ until completely dissolved, yielding a homogeneous and transparent chitosan solution. 23.5g of 4-aminoimidazole was dissolved in 250mL of deionized water and slowly added to the chitosan solution with stirring until homogeneous. Then, under ice-water bath cooling and continuous stirring, a solution prepared from 30g of glutaraldehyde and 300mL of deionized water was slowly added dropwise over 30min. After the addition was complete, the reaction system was heated to 45℃ and reacted for 8 hours under nitrogen protection. After the reaction, the resulting viscous product was poured into 10L of anhydrous ethanol for precipitation. The precipitate was collected by filtration and washed three times each with an ethanol-water mixture (4:1 volume ratio) and pure ethanol. Finally, the product was vacuum dried at 50°C for 24 hours and then pulverized to obtain modified chitosan powder.
[0035] Example Example 1: A phenol-modified silicone oil was prepared according to the following operation: Step 1: Add 1 mol (1667 g) of hydrogen-terminated silicone oil (brand name RH-H45, hydrogen content 0.12%) and 300 mL of anhydrous toluene to a flask, start stirring and purge with nitrogen for protection. Add 0.8 g of 1-ethynyl-1-cyclohexanol as an inhibitor and 255 g (2.2 mol) of hydroxyethyl acrylate sequentially, and heat the oil bath to 85°C. After the system temperature stabilizes, slowly add a mixture containing isopropanol chloroplatinate solution (25 ppm by mass of the reaction system, based on Pt) dropwise through a constant-pressure dropping funnel. After the addition is complete, continue the reaction at 85°C for 6 hours. After the reaction is complete, cool the system to room temperature, and remove the toluene solvent and unreacted hydroxyethyl acrylate by vacuum distillation to obtain a clear, viscous hydroxyl silicone oil.
[0036] Step 2: Transfer all the hydroxyl silicone oil obtained above to a reaction flask, add 544 g (4.0 mol) of tetramethylcyclotetrasiloxane (D4H), and add tetramethylammonium hydroxide at 100 ppm of the total mass of the hydroxyl silicone oil and D4H as a catalyst. Under nitrogen protection, heat the reaction mixture to 110 °C and carry out the ring-opening polymerization reaction for 4 hours. Subsequently, raise the system temperature to 125 °C and maintain this temperature for 1.5 hours to completely decompose the alkaline catalyst, obtaining the hydrogen-modified hydroxyl silicone oil.
[0037] Step 3: Cool the obtained hydrogen-modified hydroxyl silicone oil to 90°C, and add 540 g (4.5 mol) of 4-vinylphenol and 1.0 g of 1-ethynyl-1-cyclohexanol inhibitor. Under a nitrogen atmosphere, slowly add platinum catalyst (25 ppm of the total mass of the system based on Pt). Control the dropping rate to maintain the reaction temperature between 90 and 95°C, and react for 7 hours. After the reaction is complete, cool the product to below 60°C and perform vacuum distillation to remove any possible residual small molecules. Finally, pass the product through a neutral silica gel column to adsorb and remove any platinum catalyst residue, obtaining phenol-modified silicone oil.
[0038] Example 2: A phenol-modified silicone oil was prepared according to the following operation: Step 1: Add 1 mol (1820 g) of hydrogen-terminated silicone oil (brand name RH-H6, hydrogen content 0.11%) and 350 mL of anhydrous toluene to a flask, start stirring and purge with nitrogen for protection. Add 0.5 g of 1-ethynyl-1-cyclohexanol as an inhibitor and 243 g (2.1 mol) of hydroxyethyl methacrylate sequentially, and heat the oil bath to 80 °C. After the system temperature stabilizes, slowly add a mixture containing isopropanol chloroplatinate solution (15 ppm by mass of the reaction system, based on Pt) dropwise through a constant-pressure dropping funnel. After the addition is complete, continue the reaction at 80 °C for 8 hours. After the reaction is complete, cool the system to room temperature, and remove the toluene solvent and unreacted hydroxyethyl methacrylate by vacuum distillation to obtain a clear, viscous hydroxyl silicone oil.
[0039] Step 2: Transfer all the hydroxyl silicone oil obtained above to a reaction flask, add 408 g (3.0 mol) of tetramethylcyclotetrasiloxane (D4H), and add tetramethylammonium hydroxide at 55 ppm of the total mass of the hydroxyl silicone oil and D4H as a catalyst. Under nitrogen protection, heat the reaction mixture to 100°C and carry out the ring-opening polymerization reaction for 5 hours. Subsequently, raise the system temperature to 120°C and maintain this temperature for 2 hours to completely decompose the alkaline catalyst, obtaining the hydrogen-modified hydroxyl silicone oil.
[0040] Step 3: Cool the obtained hydrogen-modified hydroxyl silicone oil to 85°C, and add 396 g (3.3 mol) of 4-allylphenol and 0.85 g of 1-ethynyl-1-cyclohexanol inhibitor. Under a nitrogen atmosphere, slowly add platinum catalyst (20 ppm of total mass, Pt). Control the dropping rate to maintain the reaction temperature between 90 and 95°C, and react for 8 hours. After the reaction, cool the product to below 60°C and perform vacuum distillation to remove any remaining small molecules. Finally, pass the product through a neutral silica gel column to adsorb and remove any platinum catalyst residue, obtaining phenol-modified silicone oil.
[0041] Example 3: A phenol-modified silicone oil was prepared according to the following operation: Step 1: Add 1 mol (1110 g) of hydrogen-terminated silicone oil (brand name RH-H518, hydrogen content 0.18%) and 300 mL of anhydrous toluene to a flask, start stirring and purge with nitrogen for protection. Add 0.75 g of 1-ethynyl-1-cyclohexanol as an inhibitor and 264.5 g (2.3 mol) of hydroxyethyl acrylate sequentially, and heat the oil bath to 95 °C. After the system temperature stabilizes, slowly add a mixture containing isopropanol chloroplatinate solution (30 ppm by mass of the reaction system, based on Pt) dropwise through a constant-pressure dropping funnel. After the addition is complete, continue the reaction at 95 °C for 4 hours. After the reaction is complete, cool the system to room temperature, and remove the toluene solvent and unreacted hydroxyethyl acrylate by vacuum distillation to obtain a clear, viscous hydroxyl silicone oil.
[0042] Step 2: Transfer all the hydroxyl silicone oil obtained above to a reaction flask, add 680 g (5.0 mol) of tetramethylcyclotetrasiloxane (D4H), and add tetramethylammonium hydroxide at 200 ppm of the total mass of the hydroxyl silicone oil and D4H as a catalyst. Under nitrogen protection, heat the reaction mixture to 120 °C and carry out the ring-opening polymerization reaction for 3 hours. Subsequently, raise the system temperature to 130 °C and maintain this temperature for 1.2 hours to completely decompose the alkaline catalyst, obtaining the hydrogen-modified hydroxyl silicone oil.
[0043] Step 3: Cool the obtained hydrogen-modified hydroxyl silicone oil to 90°C, and add 600 g (5.0 mol) of 4-vinylphenol and 1.3 g of 1-ethynyl-1-cyclohexanol inhibitor. Under a nitrogen atmosphere, slowly add platinum catalyst (30 ppm of total mass, Pt). Control the dropping rate to maintain the reaction temperature between 90 and 95°C, and react for 5 hours. After the reaction is complete, cool the product to below 60°C and perform vacuum distillation to remove any remaining small molecules. Finally, pass the product through a neutral silica gel column to adsorb and remove any platinum catalyst residue, obtaining phenol-modified silicone oil.
[0044] Example 4, a phenol-modified silicone oil, differs from Example 1 in that, in step 1, an equimolar mass end-hydrogen-containing silicone oil (brand name RH-DH07, hydrogen content 0.07%) is used instead of the end-hydrogen-containing silicone oil (brand name RH-H45, hydrogen content 0.12%).
[0045] Comparative Example Comparative Example 1, a phenol-modified silicone oil, differs from Example 1 in that hydroxyethyl acrylate is replaced with equimolar mass of 4-vinylphenol in step 1; and 4-vinylphenol is replaced with equimolar mass of hydroxyethyl acrylate in step 3.
[0046] Comparative Example 2, a phenol-modified silicone oil, differs from Example 1 in that hydroxyethyl acrylate is replaced with equimolar mass of 4-vinylphenol in step 1.
[0047] Application examples Application Example 1: A polyurethane electronic packaging material is prepared according to the following steps: Under dry nitrogen protection, a mixture of 3.5 mol of polyether triol (molecular weight 3000) and 1.5 mol of polyether diol (molecular weight 2000), along with 1.35 mol of the phenol-modified silicone oil prepared in Example 1, was added to a reactor equipped with a stirrer, thermometer, and condenser. The mixture was dehydrated under reduced pressure at 60°C for 2 hours. Then, 9.45 mol of isophorone diisocyanate was slowly added. The temperature was slowly raised to 85°C, and the reaction was carried out at this temperature for 4 hours to obtain a polyurethane prepolymer. The prepolymer was then cooled to below 50°C, discharged, and sealed for storage.
[0048] Take 1000g of the above prepolymer as component A, and premix 100g of fumed silica (average particle size 3μm, prepared by surface treatment of fumed silica and KH-550 in a mass ratio of 100:3) treated with silane coupling agent KH-550, 25g of the modified chitosan powder prepared in Preparation Example 3, and 10g of stannous octoate catalyst in a high-speed mixer at 40°C to obtain component B. When using, mix component A and component B, mechanically stir at 2000rpm for 3 minutes, and then place in a vacuum drying oven for degassing at -0.095MPa for 5 minutes to obtain the final product.
[0049] Application Example 2: A polyurethane electronic packaging material is prepared according to the following steps: Under dry nitrogen protection, a mixture of 4 mol of polyether triol (molecular weight 3500) and 1 mol of polyether diol (molecular weight 1000), along with 0.84 mol of the phenol-modified silicone oil prepared in Example 2, was added to a reactor equipped with a stirrer, thermometer, and condenser. The mixture was dehydrated under reduced pressure at 70°C for 2.5 hours. Then, 9.1 mol of isophorone diisocyanate was slowly added. The temperature was slowly raised to 75°C, and the reaction was carried out at this temperature for 5 hours to obtain a polyurethane prepolymer. The prepolymer was then cooled to below 50°C, discharged, and sealed for storage.
[0050] Take 1000g of the above prepolymer as component A. Premix 50g of fumed silica (average particle size 5μm, prepared by surface treatment of fumed silica and KH-550 in a mass ratio of 100:3) treated with silane coupling agent KH-550, 15g of the modified chitosan powder prepared in Preparation Example 2, and 5g of dibutyltin dilaurate catalyst in a high-speed mixer at 40°C until homogeneous, and this mixture will be component B. In use, mix component A and component B, mechanically stir at 2000rpm for 3 minutes, and then place in a vacuum drying oven for degassing at -0.095MPa for 5 minutes to obtain the final product.
[0051] Application Example 3: A polyurethane electronic packaging material is prepared according to the following steps: Under dry nitrogen protection, a mixture of 2.5 mol of polyether triol (molecular weight 5000) and 2.5 mol of polyether diol (molecular weight 2000), along with 1.75 mol of the phenol-modified silicone oil prepared in Example 3, was added to a reactor equipped with a stirrer, thermometer, and condenser. The mixture was dehydrated under reduced pressure at 55°C for 1.5 hours. Then, 10 mol of diphenylmethane diisocyanate was slowly added. The temperature was slowly raised to 90°C, and the reaction was carried out at this temperature for 3.5 hours to obtain a polyurethane prepolymer. The prepolymer was cooled to below 50°C, discharged, and sealed for storage.
[0052] Take 1000g of the above prepolymer as component A, and premix 150g of alumina (average particle size 3μm, prepared by surface treatment of alumina and KH-550 in a mass ratio of 100:3), 35g of the modified chitosan powder prepared in Preparation Example 3, and 14g of stannous octoate catalyst in a high-speed mixer at 40°C to obtain component B. When using, mix component A and component B, mechanically stir at 2000rpm for 3 minutes, and then place in a vacuum drying oven for degassing at -0.1MPa for 5 minutes to obtain the final product.
[0053] Application Example 4 is a polyurethane electronic packaging material, which differs from Application Example 1 in that an equal amount of phenol-modified silicone oil prepared in Example 4 is used to replace the phenol-modified silicone oil prepared in Example 1.
[0054] Application Example 5 is a polyurethane electronic packaging material, which differs from Application Example 1 in that an equal mass of chitosan (85% degree of deacetylation, MW=15000) is used to replace the modified chitosan powder prepared in Preparation Example 1.
[0055] Application Example 6 is a polyurethane electronic packaging material, which differs from Application Example 1 in that the modified chitosan powder prepared in Preparation Example 1 is replaced with an equal mass of fumed silica (average particle size 3 μm, prepared by surface treatment of fumed silica and KH-550 in a mass ratio of 100:3) treated with silane coupling agent KH-550.
[0056] Comparative application examples Compared to Application Example 1, a polyurethane electronic packaging material differs from Application Example 1 in that an equal amount of phenol-modified silicone oil prepared in Comparative Example 1 is used to replace the phenol-modified silicone oil prepared in Example 1.
[0057] Comparative Application Example 2, a polyurethane electronic packaging material, differs from Application Example 1 in that an equal amount of phenol-modified silicone oil prepared in Comparative Example 2 is used to replace the phenol-modified silicone oil prepared in Example 1.
[0058] Performance testing Test 1: Resistance to Damp Heat Aging Sample preparation: The polyurethane electronic packaging material to be tested was poured into a preheated mold, cured at 80°C for 12 hours, and then cured at 100°C for 4 hours to obtain a Type 1 dumbbell-shaped sample with a total length of 115 mm, a gauge length of 50 mm, and a thickness of 2 mm (refer to GB / T 1040.2-2022).
[0059] Test procedure: Place the sample in a constant temperature and humidity test chamber and expose it continuously for 500 hours at a temperature of 85℃ and a relative humidity of 85%. After aging, remove the sample, and after conditioning it in a standard environment according to GB / T 1040-2022, test its tensile strength and calculate the tensile strength retention rate.
[0060] Experiment 2: Antioxidant Performance Test Sample preparation: The polyurethane electronic packaging material to be tested was poured into a preheated mold, cured at 80°C for 12 hours, and then cured at 100°C for 4 hours to obtain a standard dumbbell-shaped tensile specimen with dimensions of 50mm×50mm×2mm (refer to GB / T 1040.2-2022).
[0061] Test Procedure: Place a set of samples in a preheated thermal aging test chamber (150℃) for 336 hours. After aging, remove the samples, adjust them to constant weight in a standard environment, and use a colorimeter to measure the yellowing index of the flat test pieces before and after aging. Calculate ΔYI (difference in yellowing index) before and after aging. The smaller the ΔYI, the better the material's resistance to yellowing and color fading.
[0062] Experiment 3: Anti-migration performance test Sample preparation: The polyurethane electronic packaging material to be tested was cast and cured into a thin sheet (e.g., 100mm × 100mm × 1mm) according to the curing process described in Experiment 1 above. At the same time, a clean glass substrate that is inert to polyurethane was prepared.
[0063] Test Procedure: A polyurethane sheet is tightly bonded to a clean substrate and placed in a 70°C oven for 168 hours. After the experiment, the polyurethane sheet and substrate are separated, and the static water contact angle of the substrate-polyurethane contact area is immediately measured. The contact angle increment Δθ_s (°) before and after the test is calculated. If hydrophobic components in the polyurethane (such as unbonded silicone oil) migrate, a thin film will form on the substrate surface, resulting in a significant increase in the substrate's contact angle. The more severe the migration, the larger the contact angle measured on the substrate.
[0064] Experiment 4: Hardness Test Sample preparation: The polyurethane electronic packaging material to be tested was cast and cured into a thin sheet (e.g., 50mm×50mm×6mm) according to the curing process of Experiment 1 above.
[0065] Test Procedure: The test shall be conducted in accordance with GB / T 531.1-2008 "Test Method for Indentation Hardness of Vulcanized Rubber or Thermoplastic Rubber - Part 1: Shore Hardness Tester Method (Shore Hardness)". A calibrated Shore A hardness tester shall be used. The specimen shall be placed stably on a firm, level surface. The indenter foot of the hardness tester shall be pressed smoothly and without impact onto the specimen surface, parallel to the specimen surface, and the indenter shall be perpendicular to the specimen surface. The reading shall be taken within 1 second after the indenter foot makes full contact with the specimen. Five measurements shall be taken at different locations on the specimen surface, with a distance of at least 6 mm between each measurement point and at least 12 mm from the edge of the specimen. The arithmetic mean of all measurements shall be taken as the Shore A hardness value of the specimen.
[0066] Experiment 5: Deformation Resistance Test Sample preparation: The polyurethane electronic packaging material to be tested was poured and cured into a cylindrical sample with a diameter of 50 mm and a height of 25 mm according to the curing process of Experiment 1 above.
[0067] Test Procedure: The test shall be conducted in accordance with GB / T 8813-2008 "Determination of Compressive Properties of Rigid Foamed Plastics". Using a universal testing machine, measure the initial dimensions (diameter, height) of the specimen to an accuracy of 0.1 mm. Place the specimen between the two parallel compression plates of the testing machine, with the upper surface of the specimen in slight contact with the compression plates as the starting point. Set the test speed to 10% / min of the initial height of the specimen (2.5 mm / min). Start the testing machine and apply a compressive load to the specimen, recording the load and deformation until the strain reaches 10%. Based on the recorded load-deformation data, calculate the stress (load / initial cross-sectional area) and strain (deformation / initial height). Plot the stress-strain curve and calculate the slope of its linear segment, i.e., the compressive modulus (unit: MPa). At least three specimens should be tested for each group of materials, and the arithmetic mean of the compressive modulus should be taken as the result.
[0068] Table 1. Performance Test Results
[0069] Analysis of experimental results: Application Example 4 (low hydrogen content in the terminal hydrogen-containing silicone oil) showed poor performance in terms of water contact angle, anti-migration properties, and tensile strength retention. This may be because a low hydrogen content implies an excessively large molecular weight of the terminal hydrogen-containing silicone oil. An excessively long siloxane backbone reduces the functional group density of the terminal active hydroxyl groups, increases steric hindrance, and leads to a decrease in its chemical bonding efficiency (grafting rate) with the polyurethane matrix. Therefore, more silicone oil fails to bond effectively and is more prone to migration, thus reducing its hydrophobic effect (contact angle). This verifies the need to control the hydrogen content to balance reactivity and modification effect.
[0070] Application Example 5 (using chitosan without imidazole grafting) showed significantly poorer hardness and compressive modulus. This may be because unmodified chitosan can only enhance cohesion through cross-linking. In contrast, the modified chitosan in Application Example 1, etc., introduced imidazole groups, which can form ion-dipole interactions and coordination bonds with polyurethane segments, constructing a complex network and thus more effectively improving the material's hardness and resistance to deformation (compressive modulus). This indicates that imidazole modification has a positive impact on compensating for the modulus loss caused by the introduction of silicone oil.
[0071] Application Example 6 (without any chitosan) performed the worst in terms of tensile strength retention, hardness, and compressive modulus. This is likely because Application Example 6 completely lacked the cross-linking reinforcement effect of chitosan. The weakening of the polyurethane bulk modulus due to the siloxane segments was not compensated for, resulting in a significant decrease in mechanical strength after hygrothermal aging, and its hardness and resistance to deformation were also the lowest. This demonstrates the important role of introducing modified chitosan in maintaining the rigidity of polyurethane encapsulation materials.
[0072] Comparing Application Examples 1 and 2 (which used silicone oils with side-linked or grafted alcohol hydroxyl groups, respectively), both showed significant deterioration in water contact angle, anti-migration properties, and strength retention. This may be because grafting alcohol hydroxyl groups onto the side chains (Comparative Application Example 1) or not introducing alcohol hydroxyl groups (Comparative Application Example 2) both prevented the silicone oil from effectively bonding, thus failing to exert its intended durable hydrophobic, anti-migration, and reinforcing effects, ultimately leading to a decline in the overall performance of the encapsulation material.
[0073] This specific embodiment is merely an explanation of this application and is not intended to limit it. After reading this specification, those skilled in the art can make modifications to this embodiment without contributing any inventive step, but such modifications are protected by patent law as long as they fall within the scope of the claims of this application.
Claims
1. A phenol-modified silicone oil, characterized in that, The mixture comprises hydrogen-terminated silicone oil, hydroxy acrylate, tetramethylcyclotetrasiloxane, and phenol in a molar ratio of 1:2.1–2.3:3–5:3.3–6.
5. The hydrogen-terminated silicone oil and hydroxy acrylate are hydrosilylated to obtain hydroxy silicone oil. Hydroxy silicone oil is obtained by ring-opening polymerization of hydroxy silicone oil and tetramethylcyclotetrasiloxane. Hydroxylated silicone oil modified with side hydrogen is then hydrosilylated with phenol to obtain phenol-modified silicone oil; The hydrogen content of the hydrogen-terminated silicone oil is 0.1-0.2%; the phenol is selected from any one or more of 2-vinylphenol, 4-vinylphenol, 2-allylphenol, 4-allylphenol, 2-methoxy-4-allylphenol, 2-methoxy-4-vinylphenol, and 2,6-dimethoxy-4-allylphenol.
2. The phenol-modified silicone oil according to claim 1, characterized in that, The hydroxyacrylate is selected from any one or more of hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, and 4-hydroxybutyl acrylate.
3. A method for preparing a phenol-modified silicone oil, characterized in that, include: According to the raw material ratio of any one of the phenolic modified silicone oils in claims 1 to 2, hydrogen-terminated silicone oil and hydroxy acrylate are mixed evenly, heated to 80-95°C under nitrogen protection, and a platinum catalyst is added to carry out hydrosilylation to obtain hydroxy silicone oil. Hydroxy silicone oil was mixed with tetramethylcyclotetrasiloxane, an alkaline catalyst was added, and the mixture was heated to 100-120°C under nitrogen protection to carry out ring-opening polymerization, thereby obtaining hydrogen-modified hydroxy silicone oil. Hydrogen-modified hydroxyl silicone oil was mixed with phenol and heated to 85-95°C under nitrogen protection. Platinum catalyst was added to carry out hydrosilylation to obtain phenol-modified silicone oil.
4. An application of a phenol-modified silicone oil, characterized in that, The phenol-modified silicone oil according to any one of claims 1 to 2 or the phenol-modified silicone oil obtained according to claim 3 is used in polyurethane electronic packaging materials.
5. The application according to claim 4, characterized in that, The polyurethane electronic packaging material includes a polyurethane prepolymer, the raw materials of which include polyisocyanate, polyol, and phenol-modified silicone oil. The molar ratio of isocyanate groups in the polyisocyanate, alcohol hydroxyl groups in the polyol, and phenol-modified silicone oil is 1.3-1.6:1:0.05-0.
15.
6. The application according to claim 5, characterized in that, The polyurethane electronic packaging material comprises 100 parts of polyurethane prepolymer, 5-15 parts of filler, 1.5-3.5 parts of modified chitosan, and 0.5-1.5 parts of catalyst; the modified chitosan is prepared by a Schiff base reaction of chitosan, dialdehyde crosslinking agent, and aminoimidazol in a mass ratio of 1:0.2-0.3:0.15-0.
25.
7. The application according to claim 6, characterized in that, The degree of deacetylation of the chitosan is ≥85%.
8. The application according to claim 5, characterized in that, The polyols used are polyether triols and polyether diols in a molar ratio of 2 to 3:1.