Silicone rubber-based pressure-sensitive adhesive and preparation method thereof

Abstract

The invention belongs to the technical field of pressure-sensitive adhesives, and discloses a silicone rubber-based pressure-sensitive adhesive and a preparation method thereof. The invention relates to a fluorine-containing polyether modified hydroxyl-terminated polysiloxane adhesive, which is prepared from the following ingredients in parts by weight: 45 to 65 parts of fluorine-containing polyether modified hydroxyl-terminated polysiloxane, 3 to 6 parts of alkoxy silane-tributyl boron and titanate compound cross-linking agents, 6 to 12 parts of silane coupling agents KH-602 modified nano aluminum nitride, 12 to 25 parts of silicon resin-hydrogenated rosin glyceride-polyterpene resin ternary compound tackifiers and 0.2 to 1.2 parts of organic zirconium catalysts. 15-35 parts of an environment-friendly mixed solvent; 2-5 parts of a polyether amine-polyamide epoxy curing agent compound; the invention aims to overcome the defects that the existing silicone rubber-based pressure-sensitive adhesive is insufficient in temperature resistance, poor in bonding effect on base materials difficult to adhere, uneven in crosslinking, poor in filler dispersity, insufficient in key component disclosure and the like, and provides the silicone rubber-based pressure-sensitive adhesive which is innovative in component design, controllable in process and excellent in performance and the preparation method thereof.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of pressure sensitive adhesive, in particular to a silicone rubber-based pressure sensitive adhesive and a preparation method thereof. BACKGROUND

[0002] The silicone rubber-based pressure sensitive adhesive is widely used in industrial production due to its excellent high and low temperature resistance, weather resistance and chemical stability. However, the silicone rubber-based pressure sensitive adhesive in the prior art still has many technical bottlenecks. The temperature resistance is insufficient, and the long-term use temperature of most products is limited to below 200 DEG C. The adhesive strength decays and aging cracks easily occur in a high temperature environment above 220 DEG C, which cannot meet the high temperature working condition requirements of high-end equipment.

[0003] The wetting and adhesion ability to difficult-to-adhere substrates such as polytetrafluoroethylene and ceramics is poor, the adhesion is insufficient, and the adhesive layer is easily left after peeling, which affects the appearance and subsequent use of the product.

[0004] The crosslinking system design is single, and a single alkoxysilane crosslinking agent is mostly used. The crosslinking density is uneven, the interface compatibility is poor, and the mechanical properties and adhesion properties of the pressure sensitive adhesive are difficult to balance.

[0005] The filler modification method is traditional, and a single nano filler is mostly modified by a single amine silane. The dispersion of the modified filler in the silicone rubber matrix is poor, and the reinforcing and high temperature resistance effects are limited.

[0006] Some crosslinking agent components are not fully disclosed or the raw materials are difficult to obtain, which makes the technical scheme difficult to be effectively implemented.

[0007] To solve the above problems, a silicone rubber-based pressure sensitive adhesive with high temperature resistance, excellent adhesion, suitable for various difficult-to-adhere substrates, and easy to obtain raw materials and controllable process is provided. SUMMARY

[0008] The present application aims to overcome the defects of the prior art, such as insufficient temperature resistance of the silicone rubber-based pressure sensitive adhesive, poor adhesion to difficult-to-adhere substrates, uneven crosslinking, poor dispersion of fillers, and insufficient disclosure of key components, and provides a silicone rubber-based pressure sensitive adhesive with innovative component design, controllable process and excellent performance, and a preparation method thereof.

[0009] To achieve the above purpose, the present application provides the following technical scheme: The technical scheme provided by the present application is: A kind of silicone rubber-based pressure sensitive adhesive, by the following components by weight parts, comprising: fluorine-containing polyether modified hydroxyl-terminated polysiloxane 45-65 parts, alkoxysilane-titanate complex compound crosslinking agent 3-6 parts, silane coupling agent KH-602 modified nano-aluminum nitride 6-12 parts, silicon resin-hydrogenated rosin glyceride-polyterpene resin ternary complex tackifier 12-25 parts, organic zirconium catalyst 0.2-1.2 parts, environmentally friendly mixed solvent 15-35 parts, polyetheramine-polyamide epoxy curing agent compound 2-5 parts; The weight ratio of alkoxysilane and titanium acid ester complex compound in the alkoxysilane-titanate complex compound crosslinking agent is 4:1-3:1; the weight ratio of polyetheramine and polyamide epoxy curing agent in the polyetheramine-polyamide epoxy curing agent compound is 3:1-2:1; The environmentally friendly mixed solvent is prepared by compounding sec-butyl acetate and γ-butyrolactone in a weight ratio of 2:1-4:1.

[0010] Further, the number average molecular weight of the fluorine-containing polyether modified hydroxyl-terminated polysiloxane is 8000-25000, the fluorine-containing polyether segment is perfluoropolyoxypropylene segment, and the modification degree is 15%-25%; the modified silicone rubber is prepared by esterification reaction of hydroxyl-terminated polysiloxane and perfluoropolyether acid chloride, and the reaction conversion rate is ≥95%.

[0011] Further, the alkoxysilane is vinyltrimethoxysilane or phenyltriethoxysilane; in the titanium acid ester complex compound, the titanium acid ester is tetrabutyl titanate.

[0012] Further, the particle size of the silane coupling agent KH-602 modified nano-aluminum nitride is 20-50 nm, and the surface amino content of the modified nano-aluminum nitride is 1.2-1.8 mmol / g.

[0013] Further, in the polyetheramine-polyamide epoxy curing agent compound, the molecular weight of the polyetheramine is 200-400.

[0014] Further, in the ternary complex tackifier, the weight ratio of silicon resin, hydrogenated rosin glyceride, and polyterpene resin is 3:2:1-2:1:1; the organic zirconium catalyst is bis(acetylacetone) zirconium or tetrabutyl zirconate.

[0015] Further, the preparation method of the tributyl boron and titanate complex is as follows: tributyl boron and tetrabutyl titanate are mixed at a molar ratio of 1:3, 50%-80% of the total volume of the two is added as anhydrous ethanol as a reaction medium, and the mixture is heated to 80-90°C under nitrogen protection, stirred and refluxed for 6-8h; then the ethanol is removed by vacuum distillation under a vacuum degree≥0.095MPa and at 60-70°C, and the product of the tributyl boron and titanate complex in the form of colorless to light yellow transparent is obtained by filtering while hot.

[0016] A preparation method of a silicone rubber-based pressure-sensitive adhesive, comprising the following steps: S1. Preparation of modified silicone rubber: hydroxyl-terminated polysiloxane is mixed with perfluoropolyether acyl chloride at a molar ratio of 1:0.15-0.25, and reacted at 75-85°C under nitrogen protection for 2-3h, and then washed and vacuum distilled to obtain fluorine-containing polyether-modified hydroxyl-terminated polysiloxane; S2. Preparation of composite curing agent: polyether amine and polyamide epoxy curing agent are mixed at a weight ratio of 3:1-2:1, stirred at 50-60°C under nitrogen protection for 60-90min, naturally cooled to room temperature after 30min of insulation, and then uniformly transparent polyether amine-polyamide epoxy curing agent composite is obtained and used as needed; S3. Preparation of modified nanofiller: nano-aluminum nitride is added to anhydrous ethanol, the solid-liquid ratio of nano-aluminum nitride to anhydrous ethanol is 1:10-1:15 (g / mL), and the mixture is ultrasonically dispersed for 15-20min to obtain a suspension; 3%-6% of the nano-aluminum nitride is added with silane coupling agent KH-602, and the mixture is stirred at 70-80°C and 300-400r / min for 2-3h; then the mixture is centrifuged, vacuum dried at 80-100°C for 4-6h to obtain silane coupling agent KH-602 modified nano-aluminum nitride, which is used as needed; S4. Preparation of pre-dispersion system: the modified silicone rubber prepared in S1 is added to an environmentally friendly mixed solvent, stirred at 55-65°C and 400-600r / min for 40-50min, and then the modified nano-aluminum nitride prepared in S3 is added, first ultrasonically dispersed at 300-400W for 30-40min, and then heated to 70-80°C and stirred at 800-1000r / min for 80-100min; S5. Crosslinking of composite system: the pre-dispersion system is added with a ternary compounded tackifier, stirred at 75-85°C for 30-40min, and then the alkoxysilane-tributyl boron and titanate complex composite crosslinking agent is added dropwise at a speed of 0.3-0.8 parts / min, and stirred for 60-80min; after the temperature is lowered to 40-50°C, the organic zirconium catalyst and the polyether amine-polyamide epoxy curing agent composite prepared in S2 are added, and the mixture is continuously stirred for 30-40min; S6. Graded curing: the mixed solution is coated on the substrate with a coating thickness of 25-60 μm; first pre-cured at 85-95℃ in a ventilated environment for 40-50 min, and then finally cured by gradient heating: 130℃ for 30 min, 135℃ for 30 min, 140-145℃ for 60 min; naturally cooled to room temperature to obtain the finished product.

[0017] Further, in S5, the addition speed of the polyether amine-polyamide epoxy curing agent complex is 0.3-0.5 parts / min to avoid uneven local crosslinking.

[0018] Further, in S3, the system temperature is controlled not to exceed 60℃ during ultrasonic dispersion to prevent rapid evaporation of anhydrous ethanol.

[0019] The beneficial effects of the technical solution are: (1) In the technical solution, silane coupling agent KH-602 modified nano-aluminum nitride is used as the key modified component. The diamine group structure can provide more active sites and form a stable chemical bond with the silicone rubber matrix, effectively solving the problems of poor dispersion and insufficient interfacial compatibility of traditional fillers. The synergistic effect of the properties of nano-aluminum nitride and the modification of diamine groups gives the pressure-sensitive adhesive excellent high-temperature stability and mechanical enhancement effect. At the same time, the composite crosslinking agent composed of alkoxysilane, tributyl boron, and titanate complex forms a synergistic effect between the activity of tributyl boron and the crosslinking properties of titanate. By reasonable proportioning, a double crosslinking network is formed, which can more uniformly improve the crosslinking density of the system and more accurately control the distribution of crosslinking nodes, further strengthening the structural stability of the pressure-sensitive adhesive and meeting the long-term use requirements under high-temperature conditions.

[0020] (2) The design of the composite components further optimizes the bonding performance. The composite formed by polyether amine and polyamide epoxy curing agent in a specific ratio forms a synergistic effect with the composite crosslinking system, which not only improves the compactness of the crosslinking network, but also improves the wetting ability of the pressure-sensitive adhesive to difficult-to-bond substrates such as polytetrafluoroethylene and ceramics, achieving a balance between bonding strength and adhesion. The combination of fluorine-containing polyether modified hydroxyl-terminated polysiloxane and the ternary adhesion promoter of silicone resin-hydrogenated rosin glyceride-polyterpene resin not only maintains the weather resistance advantage of silicone rubber-based materials, but also optimizes the initial adhesion and cohesive strength of the pressure-sensitive adhesive through the multi-synergistic effect of the adhesion promoter, effectively avoiding the phenomenon of residual glue after peeling, and widening the range of applicable substrates for the product.

[0021] (3) The environmentally friendly mixed solvent of sec-butyl acetate and γ-butyrolactone not only ensures the sufficient dissolution and uniform dispersion of each component (including the tributyl boron and titanate compound) but also meets the environmental protection requirements of industrial production and has no residual impurities after volatilization. The selection of the organic zirconium catalyst has good adaptability with other components in the system, can gently control the crosslinking reaction rate, avoids local excessive crosslinking, especially can adapt to the crosslinking reaction characteristics of the tributyl boron and titanate compound, and ensures the stability of the system reaction. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 A preparation process schematic diagram of a silicone rubber-based pressure-sensitive adhesive and a preparation method thereof according to the present application. DETAILED DESCRIPTION

[0023] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0024] The specific implementation process is as follows: Embodiment 1 Please refer to Figure 1 The present application provides a technical solution: a silicone rubber-based pressure-sensitive adhesive and a preparation method thereof, which comprises the following components: fluorine-containing polyether modified hydroxyl-terminated polysiloxane 45 kg, vinyltrimethoxysilane-tributyl boron and titanate compound complex crosslinking agent 3 kg (weight ratio of vinyltrimethoxysilane and tributyl boron and titanate compound is 4:1, i.e. vinyltrimethoxysilane 2.4 kg, tributyl boron and titanate compound 0.6 kg, wherein the type of vinyltrimethoxysilane is A-171), silane coupling agent KH-602 modified nano-aluminum nitride (particle size 30 nm) 6 kg, silicone resin-hydrogenated rosin glyceride-polyterpene resin ternary complex tackifier 12 kg (weight ratio 3:2:1, i.e. silicone resin (SR-1000 (Dow Corning)) 6 kg, hydrogenated rosin glyceride (Foral 85 (BASF)) 4 kg, polyterpene resin (PICCOTAC 95 (Eastman Chemical)) 2 kg), bis(acetylacetone) zirconium 0.2 kg, sec-butyl acetate-γ-butyrolactone environmentally friendly mixed solvent 15 kg (weight ratio 4:1, i.e. sec-butyl acetate 12 kg, γ-butyrolactone 3 kg), polyether amine-polyamide epoxy curing agent compound 2 kg (weight ratio 3:1, i.e. polyether amine (Jeffamine D-230) 1.5 kg, polyamide epoxy curing agent (Epikure 3140) 0.5 kg).

[0025] Preparation method S1. Preparation of fluorinated polyether modified hydroxyl-terminated polysiloxane: Hydroxyl-terminated polysiloxane (DC-1248 (Dow Corning, viscosity 5000 mPa)) was prepared. . s, hydroxyl content 0.15wt%) and perfluorinated polyether acyl chloride (Fomblin Z-DOL acyl chloride derivative (Sowes Chemical, number average molecular weight 1000-1500)) were mixed at a molar ratio of 1:0.15 and reacted at 75℃ under nitrogen protection for 3h. After washing three times with deionized water (each time the amount of water was 1 / 2 of the total mass of the reaction system) and vacuum distilled at 80℃ (vacuum degree 0.09MPa) for 2h, fluorinated polyether modified hydroxyl-terminated polysiloxane was obtained. S2. Preparation of polyetheramine-polyamide epoxy curing agent composite: 1.5 kg of polyetheramine and 0.5 kg of polyamide epoxy curing agent were mixed at a weight ratio of 3:1. The mixture was stirred at 300 r / min for 90 min at 50 °C under nitrogen protection. After holding at the temperature for 30 min, the mixture was naturally cooled to room temperature to obtain a uniform and transparent polyetheramine-polyamide epoxy curing agent composite for later use. S3. Preparation of modified nano-aluminum nitride: 6 kg of nano-aluminum nitride was added to 60 L of anhydrous ethanol (solid-liquid ratio 1:10 g / mL), and ultrasonically dispersed at 300 W for 20 min to obtain a suspension (controlling the system temperature ≤60℃); 0.18 kg of silane coupling agent KH-602 was weighed at 3% of the weight of nano-aluminum nitride and added to the above suspension, and stirred at 70℃ and 300 r / min for 3 h for modification; then centrifuged at 8000 r / min for 10 min, the precipitate was collected and vacuum dried at 80℃ (vacuum degree 0.09 MPa) for 6 h to obtain silane coupling agent KH-602 modified nano-aluminum nitride for later use; S4. Preparation of composite crosslinking agent: Weigh 2.4 kg of vinyltrimethoxysilane and 0.6 kg of tributylboron and titanate composite at a weight ratio of 4:1, mix them evenly and set aside. The preparation of the tributylboron-titanium ester composite was as follows: tributylboron and tetrabutyl titanate were mixed in a molar ratio of 1:3, and anhydrous ethanol was added as 50% of the total volume of the two as the reaction medium. The mixture was heated to 80°C under nitrogen protection and stirred under reflux for 8 hours. Subsequently, the ethanol was removed by vacuum distillation at 0.095 MPa and 60°C, and the mixture was filtered while hot (the filter medium was qualitative filter paper with a pore size of 1-3 μm) to obtain the finished tributylboron-titanium ester composite. S5. Preparation of pre-dispersion system: 45 kg of fluorinated polyether modified hydroxyl-terminated polysiloxane prepared by S1 was added to 15 kg of environmentally friendly mixed solvent (12 kg of sec-butyl acetate + 3 kg of γ-butyrolactone), and stirred at 55℃ and 400 r / min for 50 min. Then, 6 kg of modified nano aluminum nitride prepared by S3 was added, and ultrasonically dispersed at 300 W for 40 min (temperature controlled ≤60℃). The temperature was raised to 70℃ and stirred at 800 r / min for 100 min to obtain a uniform pre-dispersion system. S6. Crosslinking of the composite system: Add 12 kg of ternary compound tackifier (6 kg of silicone resin + 4 kg of hydrogenated rosin glycerol ester + 2 kg of polyterpene resin) to the pre-dispersion system, stir at 75℃ for 40 min, add 3 kg of composite crosslinking agent prepared by S4 dropwise at a rate of 0.3 kg / min, and stir for 80 min; after cooling to 40℃, add 0.2 kg of bis(acetylacetone)zirconium and 2 kg of composite curing agent prepared by S2 (addition rate of 0.3 kg / min), and continue stirring at 400 r / min for 40 min to obtain the crosslinked mixture; S7. Graded curing: The mixture is evenly coated onto the surface of the polytetrafluoroethylene vinyl material using a doctor blade coater, with a coating thickness of 25μm; it is first pre-cured at 85℃ in a ventilated environment for 50min (ventilation speed 0.5m / s), and then finally cured by gradient temperature increase: 130℃ for 30min, 135℃ for 30min, and 140℃ for 60min; after natural cooling to room temperature (25℃), the silicone rubber-based pressure-sensitive adhesive product is obtained.

[0026] Test item Test result Peeling strength (N / 25mm, 25°C) 2.1 Peeling strength after 1000h aging at 230°C (N / 25mm) 1.91 Performance retention rate after 1000h aging at 230°C (%) 91 Tack free time (h, 25°C, 1kg load) 42 Residual adhesive condition (polytetrafluoroethylene substrate) No visible residual adhesive The silicone rubber-based pressure-sensitive adhesive prepared in this embodiment achieves a peel strength of 2.1 N / 25 mm at 25°C on polytetrafluoroethylene (PTFE) substrates, meeting the bonding strength requirements for difficult-to-bond substrates. After aging at 230°C for 1000 hours, the peel strength remains at 1.91 N / 25 mm, with a performance retention rate of 91%, demonstrating excellent high-temperature stability. Under 25°C and a 1 kg load, the tackiness lasts for 42 hours, and no visible adhesive residue is left on the substrate surface after peeling, solving the problems of insufficient tackiness and easy residue in traditional pressure-sensitive adhesives for difficult-to-bond substrates. The data verifies the synergistic effect of the modified and composite components at low formulation ratios, achieving good overall performance even at the lowest possible dosage of each component.

[0027] Example 2: Please see Figure 1 The present invention provides a technical solution: a silicone rubber-based pressure-sensitive adhesive and its preparation method, comprising the following components: 55 kg of fluorinated polyether-modified hydroxyl-terminated polysiloxane, 4.5 kg of vinyltrimethoxysilane-tributylborone-titanium ester composite crosslinking agent (weight ratio of vinyltrimethoxysilane and tributylborone-titanium ester composite 3.5:1, i.e., vinyltrimethoxysilane 3.675 kg, tributylborone-titanium ester composite 0.825 kg, of which vinyltrimethoxysilane is model A-171), 9 kg of silane coupling agent KH-602 modified nano aluminum nitride (particle size 30 nm), 18 kg of silicone resin-hydrogenated rosin glycerol ester-polyterpene resin ternary compound tackifier (weight ratio 2.5:1.5:1, i.e., silicone resin (SR-1000 (Dow Corning) 9 kg, hydrogenated rosin glycerol ester (Foral 85 (BASF)) 5.4 kg, polyterpene resin (PICCOTAC) 18 ...9 kg of silane coupling agent KH-602 modified nano aluminum nitride (particle size 30 nm), 9 kg of silane coupling agent KH-602 modified nano aluminum nitride (particle size 30 nm), 9 kg of sil 95 (Eastman Chemicals) 3.6kg), bis(acetylacetone)zirconium 0.7kg, sec-butyl acetate-γ-butyrolactone environmentally friendly mixed solvent 25kg (weight ratio 3:1, i.e. sec-butyl acetate 18.75kg, γ-butyrolactone 6.25kg), polyetheramine-polyamide epoxy curing agent composite 3.5kg (weight ratio 2.5:1, i.e. polyetheramine (Jeffamine D-230) 2.5kg, polyamide epoxy curing agent (Epikure 3140) 1kg).

[0028] Preparation method S1. Preparation of fluorinated polyether modified hydroxyl-terminated polysiloxane: Hydroxyl-terminated polysiloxane (DC-1248 (Dow Corning, viscosity 5000 mPa)) was prepared. . s, hydroxyl content 0.15wt%) and perfluorinated polyether acyl chloride (Fomblin Z-DOL acyl chloride derivative (Sowes Chemical, number average molecular weight 1000-1500)) were mixed at a molar ratio of 1:0.2 and reacted at 80℃ under nitrogen protection for 2.5h. After washing three times with deionized water (each time the amount of water was 1 / 2 of the total mass of the reaction system) and vacuum distilled at 85℃ (vacuum degree 0.09MPa) for 1.5h, fluorinated polyether modified hydroxyl-terminated polysiloxane was obtained. S2. Preparation of polyetheramine-polyamide epoxy curing agent composite: 2.5 kg of polyetheramine and 1 kg of polyamide epoxy curing agent were mixed at a weight ratio of 2.5:1. The mixture was stirred at 400 r / min for 75 min under nitrogen protection at 55 °C. After holding at the temperature for 30 min, it was naturally cooled to room temperature to obtain a uniform and transparent polyetheramine-polyamide epoxy curing agent composite for later use. S3. Preparation of modified nano-aluminum nitride: 9 kg of nano-aluminum nitride was added to 112.5 L of anhydrous ethanol (solid-liquid ratio 1:12.5 g / mL), and ultrasonically dispersed at 350 W for 18 min to obtain a suspension (controlling the system temperature ≤60℃); 0.405 kg of silane coupling agent KH-602 was weighed as 4.5% of the weight of nano-aluminum nitride and added to the above suspension, and stirred at 75℃ and 350 r / min for 2.5 h for modification; then centrifuged at 8000 r / min for 10 min, the precipitate was collected and vacuum dried at 90℃ (vacuum degree 0.09 MPa) for 5 h to obtain silane coupling agent KH-602 modified nano-aluminum nitride for later use; S4. Preparation of composite crosslinking agent: Weigh 3.675 kg of vinyltrimethoxysilane and 0.825 kg of tributylborone and titanate composite at a weight ratio of 3.5:1, mix them evenly and set aside; The preparation of tributylborone and titanate composite: Mix tributylborone and tetrabutyl titanate at a molar ratio of 1:3, add 65% of the total volume of anhydrous ethanol as the reaction medium, heat to 85℃ under nitrogen protection, stir and reflux for 7 h; Then remove ethanol by vacuum distillation under vacuum of 0.098 MPa and 65℃, filter while hot (the filter medium is qualitative filter paper with a pore size of 1-3 μm) to obtain the finished tributylborone and titanate composite; S5. Preparation of pre-dispersion system: 55 kg of fluorinated polyether modified hydroxyl-terminated polysiloxane prepared by S1 was added to 25 kg of environmentally friendly mixed solvent (18.75 kg of sec-butyl acetate + 6.25 kg of γ-butyrolactone), and stirred at 60℃ and 500 r / min for 45 min. Then, 9 kg of modified nano aluminum nitride prepared by S3 was added, and ultrasonically dispersed at 350 W for 35 min (temperature controlled ≤60℃). The temperature was raised to 75℃ and stirred at 900 r / min for 90 min to obtain a uniform pre-dispersion system. S6. Crosslinking of the composite system: Add 18 kg of ternary compound tackifier (9 kg of silicone resin + 5.4 kg of hydrogenated rosin glycerol ester + 3.6 kg of polyterpene resin) to the pre-dispersed system, stir at 80℃ for 35 min, add 4.5 kg of composite crosslinking agent prepared by S4 dropwise at a rate of 0.55 kg / min, and stir for 70 min; after cooling to 45℃, add 0.7 kg of bis(acetylacetone)zirconium and 3.5 kg of composite curing agent prepared by S2 (addition rate 0.4 kg / min), and continue stirring at 500 r / min for 35 min to obtain the crosslinked mixture; S7. Graded curing: The mixture is evenly coated onto the surface of the polycarbonate substrate using a doctor blade coater to a thickness of 40μm; it is first pre-cured at 90℃ in a ventilated environment for 45min (ventilation speed 0.5m / s), and then finally cured by gradient temperature increase: 130℃ for 30min, 135℃ for 30min, and 142℃ for 60min; after natural cooling to room temperature (25℃), the silicone rubber-based pressure-sensitive adhesive product is obtained.

[0029] Test item Test result Peeling strength (N / 25mm, 25°C) 2.6 Peeling strength after 1000h aging at 230°C (N / 25mm) 2.47 Performance retention rate after 1000h aging at 230°C (%) 95 Tack free time (h, 25°C, 1kg load) 56 Residual adhesive condition (polycarbonate substrate) No visible residual adhesive This embodiment, as an intermediate formulation, yielded a silicone rubber-based pressure-sensitive adhesive with optimal overall performance: a peel strength of 2.6 N / 25 mm against a polycarbonate substrate at 25°C, significantly higher than traditional pressure-sensitive adhesives; a performance retention rate of up to 95% after 1000 hours of high-temperature aging at 230°C, with a peel strength still reaching 2.47 N / 25 mm, demonstrating excellent high-temperature stability; and a holding power of up to 56 hours, with no adhesive residue left on the substrate after peeling. The data fully validates the synergistic crosslinking effect of the modified component (diamine-modified nano-aluminum nitride), the composite component (polyetheramine-polyamide epoxy composite), and the composite crosslinking agent (alkoxysilane-tributylborone and titanate). The intermediate formulation maximizes the effectiveness of each component, achieving a perfect balance between adhesive strength, high-temperature resistance, and holding power.

[0030] Example 3: Please see Figure 1 The present invention provides a technical solution: a silicone rubber-based pressure-sensitive adhesive and its preparation method, comprising the following components: Fluorinated polyether modified hydroxyl-terminated polysiloxane 65kg, phenyltriethoxysilane-tributylborone and titanate composite crosslinking agent 6kg (vinyltrimethoxysilane and tributylborone and titanate composite in a weight ratio of 3:1, i.e., phenyltriethoxysilane 4.5kg, tributylborone and titanate composite 1.5kg), silane coupling agent KH-602 modified nano aluminum nitride (particle size 30nm) 12kg, silicone resin-hydrogenated rosin glycerol ester-polyterpene resin ternary compound tackifier 25kg (weight ratio 2:1:1, i.e. silicone resin (SR-1000 (Dow Corning)) 12.5kg, hydrogenated rosin glycerol ester (Foral 85 (BASF)) 6.25kg, polyterpene resin (PICCOTAC) 95 (Eastman Chemicals) 6.25kg), tetrabutylzirconate 1.2kg, sec-butyl acetate-γ-butyrolactone environmentally friendly mixed solvent 35kg (weight ratio 2:1, i.e. sec-butyl acetate 23.33kg, γ-butyrolactone 11.67kg), polyetheramine-polyamide epoxy curing agent composite 5kg (weight ratio 2:1, i.e. polyetheramine (Jeffamine D-230) 3.33kg, polyamide epoxy curing agent (Epikure 3140) 0.5kg) 1.67kg).

[0031] Preparation method S1. Preparation of fluorinated polyether modified hydroxyl-terminated polysiloxane: Hydroxyl-terminated polysiloxane (DC-1248 (Dow Corning, viscosity 5000 mPa)) was prepared. . s, hydroxyl content 0.15wt%) and perfluorinated polyether acyl chloride (Fomblin Z-DOL acyl chloride derivative (Sowes Chemical, number average molecular weight 1000-1500)) were mixed at a molar ratio of 1:0.25 and reacted at 85℃ under nitrogen protection for 2h. After washing three times with deionized water (each time the amount of water was 1 / 2 of the total mass of the reaction system) and vacuum distilled at 90℃ (vacuum degree 0.09MPa) for 1h, fluorinated polyether modified hydroxyl-terminated polysiloxane was obtained. S2. Preparation of polyetheramine-polyamide epoxy curing agent composite: 3.33 kg of polyetheramine and 1.67 kg of polyamide epoxy curing agent were mixed at a weight ratio of 2:1. The mixture was stirred at 400 r / min for 60 min under nitrogen protection at 60 °C. After holding at the temperature for 30 min, the mixture was naturally cooled to room temperature to obtain a uniform and transparent polyetheramine-polyamide epoxy curing agent composite for later use. S3. Preparation of modified nano-aluminum nitride: 12 kg of nano-aluminum nitride was added to 180 L of anhydrous ethanol (solid-liquid ratio 1:15 g / mL), and ultrasonically dispersed at 400 W for 15 min to obtain a suspension (controlling the system temperature ≤60℃); 0.72 kg of silane coupling agent KH-602 was weighed at 6% of the weight of nano-aluminum nitride and added to the above suspension, and stirred and modified at 80℃ and 400 r / min for 2 h; then centrifuged at 8000 r / min for 10 min, the precipitate was collected and vacuum dried at 100℃ (vacuum degree 0.09 MPa) for 4 h to obtain silane coupling agent KH-602 modified nano-aluminum nitride for later use; S4. Preparation of composite crosslinking agent: Weigh 4.5 kg of phenyltriethoxysilane and 1.5 kg of tributylboron and titanate complex at a weight ratio of 3:1, mix them evenly and set aside; Preparation of tributylboron and titanate complex: Mix tributylboron and tetrabutyl titanate at a molar ratio of 1:3, add 80% of the total volume of anhydrous ethanol as the reaction medium, heat to 90℃ under nitrogen protection, stir and reflux for 6 h; then remove ethanol by vacuum distillation at 0.1 MPa and 70℃, filter while hot (filter medium is qualitative filter paper, pore size 1-3 μm) to obtain the finished tributylboron and titanate complex; S5. Preparation of pre-dispersion system: 65 kg of fluorinated polyether modified hydroxyl-terminated polysiloxane prepared by S1 was added to 35 kg of environmentally friendly mixed solvent (23.33 kg of sec-butyl acetate + 11.67 kg of γ-butyrolactone), and stirred at 65℃ and 600 r / min for 40 min. Then, 12 kg of modified nano aluminum nitride prepared by S3 was added, and ultrasonic dispersion was carried out at 400 W for 30 min (temperature controlled ≤60℃). The temperature was raised to 80℃ and high-speed stirring at 1000 r / min was carried out for 80 min to obtain a uniform pre-dispersion system. S6. Crosslinking of the composite system: Add 25 kg of ternary compound tackifier (12.5 kg of silicone resin + 6.25 kg of hydrogenated rosin glycerol ester + 6.25 kg of polyterpene resin) to the pre-dispersed system, stir at 85°C for 30 min, add 6 kg of composite crosslinking agent prepared by S4 dropwise at a rate of 0.8 kg / min, and stir for 60 min; after cooling to 50°C, add 1.2 kg of tetrabutylzirconate and 5 kg of composite curing agent prepared by S2 (addition rate 0.5 kg / min), and continue stirring at 600 r / min for 30 min to obtain the crosslinked mixture; S7. Graded curing: The mixture is evenly coated onto the surface of the ceramic substrate using a doctor blade coater to a thickness of 60μm; it is first pre-cured at 95℃ in a ventilated environment for 40min (ventilation speed 0.5m / s), and then finally cured by gradient temperature increase: 130℃ for 30min, 135℃ for 30min, and 145℃ for 60min; after natural cooling to room temperature (25℃), the silicone rubber-based pressure-sensitive adhesive product is obtained.

[0032] Test item Test result Peeling strength (N / 25mm, 25°C) 3.0 Peeling strength after 1000h aging at 230°C (N / 25mm) 2.94 Performance retention rate after 1000h aging at 230°C (%) 98 Tack free time (h, 25°C, 1kg load) 68 Residual adhesive condition (ceramic substrate) No visible residual adhesive This embodiment employs the highest formulation ratio, resulting in a silicone rubber-based pressure-sensitive adhesive with optimal performance across the board: a peel strength of 3.0 N / 25 mm against ceramic substrates at 25°C, far exceeding the bonding strength of traditional pressure-sensitive adhesives; 98% performance retention after 1000 hours of high-temperature aging at 230°C, with a peel strength still reaching 2.94 N / 25 mm, demonstrating exceptional high-temperature stability; and a holding power of up to 68 hours, more than three times that of traditional pressure-sensitive adhesives, with no adhesive residue left on the ceramic substrate after peeling. The data indicates that the high formulation ratio significantly amplifies the reinforcing and thermally conductive effects of modified nano-aluminum nitride, as well as the synergistic crosslinking effect of the composite curing agent and composite crosslinking agent, forming a high-density, highly stable crosslinked network suitable for high-end applications requiring extremely high temperature resistance and bonding strength.

[0033] Comparative Example 1: Please see Figure 1 The present invention provides a technical solution: compared with Example 2, unmodified nano-aluminum nitride is replaced with ordinary nano-aluminum nitride, and the rest is the same as Example 2; Preparation method Except for step S3, which is replaced by "adding 9 kg of ordinary nano aluminum nitride to 112.5 L of anhydrous ethanol (solid-liquid ratio 1:12.5 g / mL), ultrasonically dispersing at 350 W for 18 min to obtain a suspension (controlling the system temperature ≤60℃); without adding silane coupling agent KH-602, directly centrifuging at 8000 r / min for 10 min, collecting the precipitate and vacuum drying at 90℃ (vacuum degree 0.09 MPa) for 5 h for later use", the remaining steps are completely consistent with Example 2.

[0034] Test item Test result Peeling strength (N / 25mm, 25°C) 1.5 Peeling strength after 1000h aging at 230°C (N / 25mm) 1.08 Performance retention rate after 1000h aging at 230°C (%) 72 Tack free time (h, 25°C, 1kg load) 28 Residual adhesive condition (polycarbonate substrate) Slightly visible residual adhesive This comparative example did not use the silane coupling agent KH-602 to modify the nano-aluminum nitride; instead, ordinary nano-aluminum nitride was used directly, resulting in a significant decrease in various properties: the peel strength at 25°C was only 1.5 N / 25 mm, a 42.3% reduction compared to Example 2; the performance retention rate after aging at 230°C for 1000 hours was 72%, far lower than the 95% of Example 2; and the tackiness was only 28 hours, less than half that of Example 2, with slight residue remaining after peeling. The data demonstrates that bis(amine)silane modification is key to improving the interfacial compatibility between nano-aluminum nitride and the silicone rubber matrix. Ordinary nano-aluminum nitride has low surface activity and poor dispersibility, failing to provide reinforcement and high-temperature resistance.

[0035] Comparative Example 2: Please see Figure 1 The present invention provides a technical solution: compared with Example 2, there is no composite curing agent, and a single polyetheramine is used instead, and the rest is the same as Example 2; Preparation method Except for step S2 being omitted and step S6 involving the addition of 3.5 kg of polyetheramine to replace the composite curing agent, the remaining steps are completely consistent with those in Example 2.

[0036] Test item Test result Peeling strength (N / 25mm, 25°C) 1.7 Peeling strength after 1000h aging at 230°C (N / 25mm) 1.33 Performance retention rate after 1000h aging at 230°C (%) 78 Tack free time (h, 25°C, 1kg load) 32 Residual adhesive condition (polycarbonate substrate) No visible residual adhesive In this comparative example, a single polyetheramine was used to replace the polyetheramine-polyamide epoxy curing agent composite, and the performance was significantly inferior to that of Example 2: the peel strength at 25°C was 1.7 N / 25 mm, a decrease of 34.6% compared to Example 2; the aging performance retention rate at 230°C was 78%, lower than the 95% of Example 2; and the tackiness at 32 h was reduced by 42.9% compared to Example 2. The data show that the combination of polyetheramine and polyamide epoxy curing agent (3:1-2:1) can form a synergistic crosslinking effect, improving the stability and density of the crosslinking network. The crosslinking efficiency of a single polyetheramine is limited, and it cannot achieve the same high-temperature resistance and tackiness, thus verifying the necessity of the composite component of this invention.

[0037] Comparative Example 3: Please see Figure 1 The present invention provides a technical solution: compared with Example 2, a single crosslinking agent is used, without the tributylboron and titanate complex, and the rest is the same as Example 2; Preparation method Except for step S4, which is omitted and 4.5 kg of vinyltrimethoxysilane is used directly as a crosslinking agent, the remaining steps are completely consistent with those in Example 2.

[0038] Test item Test result Peeling strength (N / 25mm, 25°C) 1.6 Peeling strength after 1000h aging at 230°C (N / 25mm) 1.28 Performance retention rate after 1000h aging at 230°C (%) 80 Tack free time (h, 25°C, 1kg load) 30 Residual adhesive condition (polycarbonate substrate) Slightly visible residual adhesive In this comparative example, a single vinyltrimethoxysilane was used to replace the alkoxysilane-tributylborane and titanate composite crosslinking agent, resulting in a significant decrease in performance: the peel strength at 25°C was 1.6 N / 25 mm, a decrease of 38.5% compared to Example 2; the aging performance retention rate at 230°C was 80%, lower than the 95% of Example 2; and the tackiness at 30 h was reduced by 46.4% compared to Example 2, with slight residue remaining. The data demonstrate that the composite of the tributylborane and titanate complex with alkoxysilane (4:1-3:1) optimizes the crosslinking density and uniformity. The introduction of boron improves the high-temperature stability of the crosslinking network, an effect that a single alkoxysilane crosslinking agent cannot achieve, thus verifying the superiority of the composite crosslinking system of this invention.

[0039] Comparative Example 4: Please see Figure 1 The present invention provides a technical solution: compared with Example 2, traditional aminopropyl modified nano-aluminum nitride replaces diamino modification.

[0040] Preparation method Except for step S3, in which 0.405 kg of silane coupling agent KH-602 was replaced with silane coupling agent KH-550, the other steps were completely consistent with those in Example 2.

[0041] Test item Test result Peeling strength (N / 25mm, 25°C) 1.9 Peeling strength after 1000h aging at 230°C (N / 25mm) 1.62 Performance retention rate after 1000h aging at 230°C (%) 85 Tack free time (h, 25°C, 1kg load) 38 Residual adhesive condition (polycarbonate substrate) No visible residual adhesive This comparative example uses the conventional silane coupling agent KH-550 (monoamino) to modify nano-aluminum nitride, replacing the silane coupling agent KH-602 (diamino) of this invention. The performance is lower than Example 2: the peel strength at 25°C is 1.9 N / 25 mm, a decrease of 26.9% compared to Example 2; the aging performance retention rate at 230°C is 85%, lower than the 95% of Example 2; and the tackiness at 38 h is reduced by 32.1% compared to Example 2. The data show that diaminosilanes can provide more reactive sites, enhancing the chemical bonding with the silicone rubber matrix, and the modification effect is superior to that of conventional monoaminosilanes, further verifying the innovative value of the modified components of this invention.

[0042] Comparative Example 5: Please see Figure 1 The present invention provides a technical solution: a conventional formula from the prior art: 55 kg of ordinary hydroxyl-terminated polysiloxane, 4.5 kg of methyltrimethoxysilane single crosslinking agent, 9 kg of silane coupling agent KH-550 modified nano silica (particle size 20 nm), 18 kg of silicone resin single tackifier, 0.7 kg of dibutyltin dilaurate, 25 kg of toluene solvent, and no curing agent.

[0043] Preparation method S1. Directly use 55kg of ordinary hydroxyl-terminated polysiloxane as the matrix; S2. Preparation steps without composite curing agent; S3. Add 9 kg of nano-silica to 112.5 L of anhydrous ethanol (solid-liquid ratio 1:12.5 g / mL), and ultrasonically disperse at 350 W for 18 min to obtain a suspension (controlling the system temperature ≤60℃); weigh 0.405 kg of silane coupling agent KH-550 according to 4.5% of the weight of nano-silica, add it to the above suspension, and stir and modify at 75℃ and 350 r / min for 2.5 h; after centrifugation at 8000 r / min for 10 min, collect the precipitate and vacuum dry at 90℃ (vacuum degree 0.09 MPa) for 5 h for later use; S4. No composite crosslinking agent preparation step is required; 4.5 kg of methyltrimethoxysilane is used directly as the crosslinking agent. S5. Preparation of pre-dispersion system: 55 kg of ordinary hydroxyl-terminated polysiloxane was added to 25 kg of toluene solvent and stirred at 60 °C and 500 r / min for 45 min. 9 kg of modified nano-silica prepared in S3 was added and ultrasonically dispersed at 350 W for 35 min (temperature controlled ≤60 °C). The temperature was then raised to 75 °C and stirred at 900 r / min for 90 min to obtain the pre-dispersion system. S6. Crosslinking reaction: Add 18 kg of silicone resin to the pre-dispersion system, stir at 80 °C for 35 min, add 4.5 kg of methyltrimethoxysilane dropwise at a rate of 0.55 kg / min, and stir for 70 min; after cooling to 45 °C, add 0.7 kg of dibutyltin dilaurate, and stir at 500 r / min for 35 min to obtain the crosslinked mixture; S7. Curing: The mixture is evenly coated onto the surface of the polycarbonate substrate using a doctor blade coater to a thickness of 40 μm; it is then directly cured at 120℃ for 120 min, and naturally cooled to room temperature (25℃) to obtain the finished product. Test item Test result Peeling strength (N / 25mm, 25°C) 1.2 Peeling strength after 1000h aging at 230°C (N / 25mm) 0.78 Performance retention rate after 1000h aging at 230°C (%) 65 Tack free time (h, 25°C, 1kg load) 18 Residual adhesive condition (polycarbonate substrate) Obvious visible residual adhesive This comparative example uses a conventional formulation from existing technologies, exhibiting the worst performance across all aspects: its peel strength at 25°C is only 1.2 N / 25 mm, less than half that of Example 2; its performance retention rate after aging at 230°C for 1000 hours is only 65%, far lower than the 95% of Example 2; its tackiness is only 18 hours, and significant residue remains after peeling. The data clearly demonstrate that this invention, through the innovative design of modified components (diamine-modified nano-aluminum nitride), composite components (polyetheramine-polyamide epoxy composite), and composite crosslinking agent (alkoxysilane-tributylborone and titanate composite), as well as the optimization of the stepwise dispersion-graded curing process, completely overcomes the limitations of existing technologies, achieving a qualitative leap in all performance aspects.

[0044] This technical solution, through a systematic comparison of Examples 1 to 3 and Comparative Examples 1 to 5, reveals that its core lies in the combination of bisamine-modified nano-aluminum nitride as the modifying component, a polyetheramine and polyamide epoxy curing agent compound as the composite component, and an alkoxysilane and tributylboron and titanate complex as the composite crosslinking agent, as well as the scientific design of the synergistic effect between the components, which completely breaks through the performance bottleneck of the existing technology.

[0045] Examples 1 to 3 cover different ratio ranges and are designed for difficult-to-bond substrates such as polytetrafluoroethylene and polycarbonate ceramics. They all exhibit excellent comprehensive performance, with a peel strength of up to 3.0 N / 25 mm, a performance retention rate of up to 98% after aging at 230°C for 1000 h, and a tackiness of up to 68 h with no residue. This proves that the technical solution can stably perform high performance in different application scenarios, and that the proportions of each component are scientifically and reasonably designed, with good adaptability and repeatability.

[0046] Comparative Example 1 did not use silane coupling agent KH-602 to modify nano-aluminum nitride, but only used ordinary nano-aluminum nitride, which resulted in a peel strength of 1.5 N / 25 mm, a performance retention rate of only 72% after aging at 230℃, a tackiness of only 28 h and slight residue. This clearly demonstrates that bisamine modification can significantly improve the interfacial compatibility between the filler and the silicone rubber matrix, avoid filler agglomeration, and is the key to enhancing the high temperature resistance and bonding strength of the material. Comparative Example 2, which replaced the polyetheramine and polyamide epoxy curing agent compound with a single polyetheramine, showed that the peel strength and tackiness decreased to 1.7 N / 25 mm and 32 h, respectively, and the high temperature resistance retention rate was only 78%. This highlights the synergistic crosslinking effect formed by the compounding of the two curing agents in a specific ratio, which can optimize the stability and density of the crosslinking network. A single curing agent cannot achieve the same effect. Comparative Example 3 used a single alkoxysilane as a crosslinking agent without adding the tributylboron and titanate complex. The peel strength was only 1.6 N / 25 mm, the tack lasted for 30 h, and there was slight residue. This confirms that the combination of the tributylboron and titanate complex with alkoxysilane can improve the crosslinking uniformity. The introduction of boron further improved the high temperature stability of the crosslinking network. It is difficult for a single crosslinking agent system to achieve a performance breakthrough. Comparative Example 4 used conventional γ-aminopropyltriethoxysilane monoamine-modified nano-aluminum nitride to replace the diamine-modified component of this technology. The peel strength was 1.9 N / 25 mm, the tackiness was 38 h, and the high temperature resistance retention rate was 85%, all of which were lower than the corresponding performance of Example 2. This indicates that the diamine structure can provide more reactive sites and form a more stable chemical bond with the matrix. The modification effect is significantly better than that of the traditional monoamine modification technology.

[0047] Compared with Comparative Example 5, which represents the prior art, the advantages of this technical solution are more prominent. Comparative Example 5 uses a single crosslinking agent and a single tackifier of ordinary hydroxyl-terminated polysiloxane and traditional modified nano silica, with a peel strength of only 1.2 N / 25 mm, a performance retention rate of 65% after aging at 230℃, a tackiness of 18 hours, and obvious residue. In contrast, this technical solution achieves a qualitative leap in peel strength, high temperature resistance, stability, tackiness, and residue-free performance through the synergistic effect of three core innovative components. It not only solves the key problems of insufficient temperature resistance, poor bonding effect on difficult-to-bond substrates, and easy residue in the prior art, but also ensures that the technical solution has good industrial implementation conditions by using commercially available conventional chemical raw materials and designing a scientific and feasible preparation process. It not only reflects a breakthrough improvement on the prior art, but also takes into account the practical application value, providing a better solution for bonding difficult-to-bond substrates in high-temperature environments.

[0048] To further illustrate the beneficial technical effects of the silicone rubber-based pressure-sensitive adhesive and its preparation method in the various embodiments of the present invention, relevant performance tests were conducted on the silicone rubber-based pressure-sensitive adhesive and its preparation method in Examples 1-3 and Comparative Examples 1-5. The testing method is as follows: 1. Peel strength: Under 25℃ conditions, a peel test was conducted at a speed of 300mm / min, and the force values ​​during the test were recorded.

[0049] 2. High temperature resistance: The sample was aged in an environment of 230℃ for 1000h, and the peel strength after aging was tested. The ratio of the peel strength after aging to the initial peel strength is the performance retention rate.

[0050] 3. Adhesion: Under 25℃ conditions, the sample was subjected to a 1kg load, and the time it took for the adhesive layer to detach from the substrate was recorded.

[0051] 4. Residual Adhesive: After completing the peel test, directly observe whether there is any visible residual adhesive on the surface of the substrate.

[0052] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific technical solutions or characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the technical solutions of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the implementation of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A silicone rubber based pressure sensitive adhesive, characterized in that, By weight parts, consisting of: fluorine-containing polyether modified hydroxyl-terminated polysiloxane 45-65 parts, alkoxy silane-titanate complex compound crosslinking agent 3-6 parts, silane coupling agent KH-602 modified nano-aluminum nitride 6-12 parts, silicone resin-hydrogenated rosin glyceride-polyterpene resin ternary complex tackifier 12-25 parts, organic zirconium catalyst 0.2-1.2 parts, environmentally friendly mixed solvent 15-35 parts, polyether amine-polyamide epoxy curing agent compound 2-5 parts; The weight ratio of alkoxy silane and tri-butyl boron and titanate complex compound in the alkoxy silane-titanate complex compound crosslinking agent is 4:1-3:1; the weight ratio of polyether amine and polyamide epoxy curing agent in the polyether amine-polyamide epoxy curing agent compound is 3:1-2:1; The environmentally friendly mixed solvent is prepared by compounding sec-butyl acetate and γ-butyrolactone in a weight ratio of 2:1-4:

1.

2. The silicone rubber-based pressure sensitive adhesive according to claim 1, characterized in that, The number average molecular weight of the fluorine-containing polyether modified hydroxyl-terminated polysiloxane is 8000-25000, the fluorine-containing polyether segment is perfluoropolyoxypropylene segment, and the modification degree is 15%-25%; the modified silicone rubber is prepared by esterification reaction of hydroxyl-terminated polysiloxane and perfluoropolyether acid chloride, and the reaction conversion rate is ≥95%.

3. The silicone rubber-based pressure sensitive adhesive according to claim 1, characterized in that, The alkoxy silane is vinyl trimethoxysilane or phenyl triethoxysilane; in the tri-butyl boron and titanate complex compound, the titanate is tetrabutyl titanate.

4. The silicone rubber-based pressure sensitive adhesive according to claim 1, characterized in that, The particle size of the silane coupling agent KH-602 modified nano-aluminum nitride is 20-50 nm, and the surface amino content of the modified nano-aluminum nitride is 1.2-1.8 mmol / g.

5. The silicone rubber-based pressure sensitive adhesive according to claim 1, characterized in that, The molecular weight of the polyether amine in the polyether amine-polyamide epoxy curing agent compound is 200-400.

6. The silicone rubber-based pressure sensitive adhesive according to claim 1, wherein The weight ratio of silicone resin, hydrogenated rosin glyceride, and polyterpene resin in the ternary complex tackifier is 3:2:1-2:1:1; the organic zirconium catalyst is bis(acetylacetone) zirconium or tetrabutyl zirconate.

7. The silicone rubber-based pressure sensitive adhesive according to claim 1, wherein The preparation method of the tri-butyl boron and titanate complex compound is: mixing tri-butyl boron and tetrabutyl titanate in a molar ratio of 1:3, adding 50%-80% of the total volume of anhydrous ethanol as a reaction medium, heating to 80-90℃ under nitrogen protection, and stirring under reflux for 6-8h; then remove ethanol under reduced pressure at a vacuum degree of ≥0.095MPa and 60-70℃, filter while hot to obtain colorless to light yellow transparent tri-butyl boron and titanate complex finished product.

8. A process for the preparation of a silicone rubber based pressure sensitive adhesive according to any one of claims 1 to 7, characterized in that, The method comprises the following steps: S1. Modified silicone rubber preparation: mixing hydroxyl-terminated polysiloxane and perfluoropolyether acid chloride in a molar ratio of 1:0.15-0.25, reacting at 75-85℃ under nitrogen protection for 2-3h, washing, and distilling under reduced pressure to obtain fluorine-containing polyether modified hydroxyl-terminated polysiloxane; S2. Compound curing agent preparation: mixing polyether amine and polyamide epoxy curing agent in a weight ratio of 3:1-2:1, stirring at 50-60℃ under nitrogen protection for 60-90min, naturally cooling to room temperature after 30min of insulation, and obtaining uniform transparent polyether amine-polyamide epoxy curing agent compound, ready for use; S3. Preparation of modified nanofiller: add nano-aluminum nitride into anhydrous ethanol, the solid-liquid ratio of nano-aluminum nitride to anhydrous ethanol is 1:10-1:15 (g / mL), ultrasonic dispersion for 15-20 min to obtain a suspension; add silane coupling agent KH-602 at 3%-6% of the weight of nano-aluminum nitride, stir at 70-80℃, 300-400 r / min for 2-3 h for modification; After centrifugal separation and vacuum drying at 80-100℃ for 4-6 h, the silane coupling agent KH-602 modified nano-aluminum nitride is obtained and ready for use; S4. Preparation of pre-dispersion system: add the modified silicone rubber prepared in S1 into environmentally friendly mixed solvent, stir at 55-65℃, 400-600 r / min for 40-50 min, then add the modified nano-aluminum nitride prepared in S3, first ultrasonic dispersion for 30-40 min at 300-400 W, then heat to 70-80℃, high-speed stirring at 800-1000 r / min for 80-100 min; S5. Crosslinking of composite system: add ternary compounded tackifier to the pre-dispersion system, stir at 75-85℃ for 30-40 min, then add alkoxysilane-titanate ester compound crosslinking agent at a speed of 0.3-0.8 parts / min, stir for 60-80 min; after cooling to 40-50℃, add organic zirconium catalyst and polyetheramine-polyamide epoxy curing agent compound prepared in S2, continue to stir for 30-40 min; S6. Graded curing: coat the mixed liquid on the substrate, the coating thickness is 25-60 μm; first pre-cure at 85-95℃ in a ventilated environment for 40-50 min, then use gradient heating to finally cure: 130℃ for 30 min, 135℃ for 30 min, 140-145℃ for 60 min; naturally cool to room temperature to obtain the finished product.

9. The preparation method according to claim 8, characterized in that, In S5, the addition speed of polyetheramine-polyamide epoxy curing agent compound is 0.3-0.5 parts / min to avoid uneven local crosslinking.

10. The preparation method according to claim 8, characterized in that, In S3, the system temperature is controlled not to exceed 60℃ during ultrasonic dispersion to prevent rapid evaporation of anhydrous ethanol.

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