High-adhesion uv three-proofing insulating resin containing heterocyclic modified silicone-acrylic resin and preparation method thereof

Abstract

This invention provides a high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin and its preparation method, belonging to the field of polymer materials technology. The core technical solution of this invention involves designing and synthesizing a heterocyclic modified silicone-acrylic resin as the main resin, which is prepared from organosilicon oligomers, nitrogen-containing heterocyclic monomers, and glycidyl methacrylate as raw materials. The adhesion promoter adopts a core-shell structure of silane coupling agent and phosphate ester prepolymer grafted with acrylate. Through the synergistic effect of heterocyclic, epoxy, and siloxane groups, chemical bonding and interfacial interpenetration of the substrate are achieved, forming a high-crosslink density three-dimensional network. Performance tests show that the resin of this invention has advantages of high adhesion, high insulation, fast curing, and resistance to environmental aging. The process is simple, solvent-free, and environmentally friendly, making it suitable for UV-resistant protection of PCBs and components in consumer electronics and automotive electronics, and possessing good prospects for industrial application.

Description

Technical Field

[0001] This invention relates to the field of polymer materials technology, and in particular to a high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin and its preparation method. Background Technology

[0002] UV-curable conformal insulating resins have been widely used in the electronics industry for conformal protection due to their advantages such as fast curing speed, no solvent evaporation, and high construction efficiency. However, existing technologies still have many technical shortcomings: Conventional acrylic UV conformal resins exhibit significant differences in interfacial adhesion to various substrates, such as PCB copper foil, FR-4 substrate, and engineering plastics. After environmental tests such as thermal shock, boiling water, and salt spray, they are prone to peeling and flaking, thus losing their protective effect. Although silicone-modified UV-resistant resins have excellent insulation and weather resistance, the low surface energy of silicone segments leads to insufficient adhesion to the substrate, and poor compatibility with acrylate systems, making them prone to phase separation. Existing dual-curing UV conformal resins mostly use a UV + moisture curing system, which results in slow curing speed in the shaded area and uneven distribution of crosslinking density in the coating, leading to easy degradation of insulation performance in harsh environments. Most UV-resistant conformal resins have poor resistance to high and low temperature impacts. In cyclic testing at -40℃ to 125℃, the coating is prone to micro-cracks, which reduces the insulation and protection effect.

[0003] In existing technologies, the means to improve adhesion are mostly to simply add silane coupling agents or phosphate ester adhesion promoters. These can only achieve surface interface bonding and cannot form chemical bonding and interpenetrating networks between the substrate and the coating. The effect of improving adhesion is limited and the durability is poor. At the same time, the design of resin systems often focuses on optimizing a single performance and it is difficult to take into account high adhesion, high insulation, excellent resistance to environmental aging and molding processability. Summary of the Invention

[0004] The purpose of this invention is to provide a high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin and its preparation method, which solves the technical problems of existing UV-resistant insulating resins such as poor adhesion, low substrate compatibility, poor insulation durability, and poor resistance to high and low temperature impacts.

[0005] To achieve the above-mentioned objectives, the present invention provides the following technical solution: This invention provides a high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin, which is prepared from raw materials comprising the following parts by weight: 60-75 parts of heterocyclic modified silicone-acrylic resin, 10-15 parts of UV-cationic composite curing agent, 3-8 parts of adhesion promoter, 2-5 parts of photoinitiator, and 0.5-3 parts of functional additives.

[0006] Furthermore, the heterocyclic modified silicone-acrylic resin is obtained by mixing organosilicon oligomers, nitrogen-containing heterocyclic monomers and glycidyl methacrylate, and reacting them under the action of the initiator azobisisobutyronitrile; The reaction is carried out under nitrogen atmosphere at a temperature of 75-85°C for 4-6 hours.

[0007] Furthermore, the molar ratio of the organosilicon oligomer, the nitrogen-containing heterocyclic monomer, and the glycidyl methacrylate is 1:0.2~0.5:0.5~0.8; The amount of azobisisobutyronitrile added is 0.3~0.5% of the total mass of the reaction system; The nitrogen-containing heterocyclic monomers include one or more of triazine heterocyclic monomers, imidazole heterocyclic monomers, and pyridine heterocyclic monomers.

[0008] Furthermore, the UV-cationic composite curing agent is obtained by compounding a free radical UV curing agent and a cationic curing agent at a mass ratio of 2 to 3:1.

[0009] Furthermore, the adhesion promoter is obtained by prepolymerizing a mixture of silane coupling agent and phosphate monomer to obtain a core layer prepolymer, then adding acrylate monomer and polymerizing under the action of an initiator. The prepolymerization temperature is 50~70℃, and the prepolymerization time is 1~3h; The polymerization temperature is 70~90℃, and the polymerization time is 3~4h; The silane coupling agent includes one or more of KH560, KH550 and KH570.

[0010] Furthermore, the mass ratio of the silane coupling agent to the phosphate ester monomer is 2:1~2; The amount of acrylate monomer added is 1 to 1.5 times the total mass of the silane coupling agent and the phosphate monomer, and the amount of initiator added is 0.8 to 1% of the total mass of the reaction system; The acrylate monomer is obtained by compounding methyl methacrylate and butyl acrylate in a mass ratio of 1:1~2; The initiator includes one or more of azobisisobutyronitrile, benzoyl peroxide, and dicumyl peroxide.

[0011] Furthermore, the photoinitiator comprises a compound of hydroxybenzophenone and diphenyliodonium salt in a mass ratio of 2 to 3:1, or a compound of benzyl dimethyl ketal and triaryl sulfonium salt in a mass ratio of 3:1.

[0012] Furthermore, the functional additive is composed of the following components in parts by weight: 0.1 to 0.5 parts of defoamer, 0.2 to 1 part of leveling agent, and 0.2 to 1.5 parts of antioxidant.

[0013] The present invention also provides a method for preparing the above-mentioned high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin. Under stirring conditions, the heterocyclic modified silicone-acrylic resin, UV-cationic composite curing agent, adhesion promoter and photoinitiator are mixed, functional additives are added, and stirring is continued. After filtration, the high-adhesion UV-resistant insulating resin is obtained. The heterocyclic modified silicone-acrylic resin has a solid content of ≥99% and a viscosity of 500~800 mPa·s at 25℃. The adhesion promoter has a particle size of 50~100nm.

[0014] Furthermore, the stirring speed is 800~1000 r / min, and the stirring time is 20~30 min.

[0015] The beneficial effects of this invention are: The core technical solution of this invention is to design and synthesize heterocyclic modified silicone-acrylic resin as the main resin, and combine it with a UV-cationic composite curing system, a self-made core-shell structure adhesion promoter, a high-efficiency photoinitiator and functional additives to prepare a high-adhesion UV-resistant insulating resin. Through the synergistic effect of heterocyclic groups, epoxy groups and siloxane groups in the molecular chain, chemical bonding and interfacial interpenetration with the substrate are achieved, while a three-dimensional network structure with high crosslinking density is constructed to improve insulation and aging resistance. Detailed Implementation

[0016] This invention provides a high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin, which is prepared from raw materials comprising the following parts by weight: 60-75 parts of heterocyclic modified silicone-acrylic resin, 10-15 parts of UV-cationic composite curing agent, 3-8 parts of adhesion promoter, 2-5 parts of photoinitiator, and 0.5-3 parts of functional additives.

[0017] In this invention, the amount of heterocyclic modified silicone-acrylic resin added is preferably 65 to 70 parts by weight.

[0018] In this invention, the amount of UV-cationic composite curing agent added is preferably 13 parts by weight.

[0019] In this invention, the amount of adhesion promoter added is preferably 5 to 7 parts by weight.

[0020] In this invention, the amount of photoinitiator added is preferably 3 to 4 parts by weight.

[0021] In this invention, the amount of the functional additive added is preferably 1 to 2 parts by weight.

[0022] In this invention, the heterocyclic modified silicone-acrylic resin is obtained by mixing organosilicon oligomers, nitrogen-containing heterocyclic monomers and glycidyl methacrylate, and reacting them under the action of the initiator azobisisobutyronitrile. The reaction is carried out under nitrogen atmosphere, and the reaction temperature is 75~85℃, preferably 72~82℃, more preferably 75℃; the reaction time is 4~6h, preferably 5h.

[0023] In this invention, the heterocyclic modified silicone-acrylic resin contains siloxane segments, a six-membered nitrogen-containing heterocyclic core structure, and acrylate double bonds. The siloxane segments have a linear repeating structure, providing the resin with a weather-resistant and insulating foundation. The six-membered nitrogen-containing heterocyclic core structure has strong polarity, which enhances the bonding force with the substrate. The acrylate double bonds can participate in UV curing crosslinking to construct a three-dimensional network structure.

[0024] In this invention, the molar ratio of the organosilicon oligomer, the nitrogen-containing heterocyclic monomer, and the glycidyl methacrylate is 1:0.2~0.5:0.5~0.8, preferably 1:0.3:0.6; The amount of azobisisobutyronitrile added is 0.3~0.5% of the total mass of the reaction system, preferably 0.4%; The nitrogen-containing heterocyclic monomer includes one or more of triazine heterocyclic monomers, imidazole heterocyclic monomers and pyridine heterocyclic monomers, preferably triazine heterocyclic monomers and / or imidazole heterocyclic monomers, and more preferably triazine heterocyclic monomers.

[0025] In this invention, the UV-cationic composite curing agent is obtained by compounding a free radical UV curing agent and a cationic curing agent at a mass ratio of 2 to 3:1, preferably 2.5:1.

[0026] In this invention, the adhesion promoter is obtained by prepolymerizing a mixture of silane coupling agent and phosphate monomer to obtain a core layer prepolymer, and then adding acrylate monomer and polymerizing it under the action of an initiator. The prepolymerization temperature is 50~70℃, preferably 55~65℃, more preferably 60℃; the prepolymerization time is 1~3h, preferably 2h. The polymerization temperature is 70~90℃, preferably 80℃; the polymerization time is preferably 3~4h. The silane coupling agent includes one or more of KH560, KH550 and KH570, preferably KH560 and / or KH550, and more preferably KH560.

[0027] In this invention, the adhesion promoter has a core-shell structure, with the core layer being a silane coupling agent grafted with phosphate ester and the shell layer being an acrylate copolymer, thereby achieving a dual enhancement of chemical bonding and interfacial interpenetration.

[0028] In this invention, the mass ratio of the silane coupling agent to the phosphate monomer is 2:1~2, preferably 2:1.5; The amount of acrylate monomer added is 1 to 1.5 times the total mass of the silane coupling agent and the phosphate monomer, preferably the amount of initiator added is 0.8 to 1% of the total mass of the system, preferably 0.9%; The acrylate monomer is obtained by compounding methyl methacrylate and butyl acrylate in a mass ratio of 1:1 to 2, preferably 1:1; The initiator includes one or more of azobisisobutyronitrile, benzoyl peroxide, and dicumyl peroxide.

[0029] In this invention, the photoinitiator comprises a compound of hydroxybenzophenone and diphenyliodonium salt in a mass ratio of 2 to 3:1, or a compound of benzyl dimethyl ketal and triaryl sulfonium salt in a mass ratio of 3:1.

[0030] In this invention, the functional additive is composed of the following components in parts by weight: 0.1 to 0.5 parts of defoamer, 0.2 to 1 part of leveling agent, and 0.2 to 1.5 parts of antioxidant.

[0031] In this invention, the amount of defoamer added is preferably 0.2 to 0.4 parts by weight.

[0032] In this invention, the amount of leveling agent added is preferably 0.5 to 0.8 parts by weight.

[0033] In this invention, the amount of antioxidant added is preferably 0.5 to 1.2 parts by weight, and more preferably 1 part.

[0034] In this invention, functional additives are used to improve workability and aging resistance.

[0035] The present invention also provides a method for preparing the above-mentioned high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin. Under stirring conditions, the heterocyclic modified silicone-acrylic resin, UV-cationic composite curing agent, adhesion promoter and photoinitiator are mixed, functional additives are added, and stirring is continued. After filtration, the high-adhesion UV-resistant insulating resin is obtained. The heterocyclic modified silicone-acrylic resin has a solid content of ≥99% and a viscosity of 500~800 mPa·s at 25℃. The adhesion promoter has a particle size of 50~100nm.

[0036] In this invention, the solid content of the heterocyclic modified silicone-acrylic resin is preferably >99%, and the viscosity at 25°C is preferably 600~700 mPa·s.

[0037] In this invention, the stirring speed is 800~1000 r / min, preferably 850~950 r / min; the stirring time is 20~30 min, preferably 25 min.

[0038] The technical solutions provided by the present invention will be described in detail below with reference to the embodiments, but they should not be construed as limiting the scope of protection of the present invention.

[0039] Example 1

[0040] In a four-necked flask equipped with a stirrer, condenser, and dropping funnel, polymethylhydrosiloxane with a molecular weight of 1000-1200, 2,4-diamino-6-acryloyloxy-1,3,5-triazine, and glycidyl methacrylate with a molecular weight of 1:0.3:0.5 were added. Then, azobisisobutyronitrile (AIOBR) was added at a total mass of 0.5%. The mixture was reacted at 80°C for 5 hours under nitrogen protection and then cooled to room temperature to obtain triazine heterocyclic-epoxy bifunctional modified silicone-acrylic resin with a solid content of 99% and a viscosity of 600 mPa·s at 25°C. Silane coupling agent KH560 and phosphate monomers were mixed at a mass ratio of 2:1 and reacted at 60°C for 2 hours to obtain a core-shell prepolymer. Then, 36 parts of acrylate monomers (a mixture of methyl methacrylate and butyl acrylate at a mass ratio of 1:1) and 0.8% of the total mass of the reaction system initiator (hydroxybenzophenone and diphenyliodonium salt at a mass ratio of 2:1) were added, and the mixture was heated to 80°C and reacted for 3 hours to form a core-shell structure. After cooling, an adhesion promoter was obtained. The high-speed stirring tank was set to a speed of 800 r / min. 70 parts of triazine heterocyclic-epoxy bifunctional modified silicone-acrylic resin, 9 parts of free radical UV curing agent, 3 parts of cationic curing agent, 5 parts of adhesion promoter, and 3 parts of photoinitiator (benzyl dimethyl ketal and triaryl sulfonate) were added sequentially. After stirring for 30 min, 3 parts of functional additives (0.5 parts of defoamer, 1 part of leveling agent, and 1.5 parts of antioxidant) were added. Stirring was continued for 20 min. The mixture was then filtered through a 300-mesh filter to obtain a high-adhesion UV-resistant insulating resin.

[0041] Table 1. Performance test items, standards, and test results of the resin product obtained in Example 1 and commercially available conventional products.

[0042] Example 2

[0043] Unlike Example 1, in this example, the amount of each raw material added is 70 parts of triazine heterocyclic-epoxy bifunctional modified silicone propylene resin, 10 parts of UV-cationic composite curing agent, 6 parts of self-made core-shell structure adhesion promoter, 4 parts of high-efficiency photoinitiator, 0.4 parts of defoamer, 0.6 parts of leveling agent, and 1.0 part of antioxidant.

[0044] Performance test results: Cross-cut adhesion rating of 0 on all substrates, maintained at 0 after boiling water / thermal shock / salt spray tests; volume resistivity 3.0×10⁻⁶. 16 Ω·cm, dielectric strength 50kV / mm; UV-LED surface drying 2s, complete curing 8s, complete curing in shaded areas 18h; pencil hardness 5H, impact strength 60kg·cm; performance retention rate 94% after 1000h QUV aging; viscosity at 25℃ 1200mPa·s, solid content 99.2%.

[0045] Example 3

[0046] Unlike Example 1, in this example, the amount of each raw material added is 60 parts of triazine heterocyclic-epoxy bifunctional modified silicone propylene resin, 15 parts of UV-cationic composite curing agent, 4 parts of self-made core-shell structure adhesion promoter, 2 parts of high-efficiency photoinitiator, 0.2 parts of defoamer, 0.3 parts of leveling agent, and 0.5 parts of antioxidant.

[0047] Performance test results: Cross-cut adhesion rating of 0 on all substrates, maintained at 0 after boiling water / thermal shock / salt spray tests; volume resistivity 2.0×10⁻⁶. 16 Ω·cm, dielectric strength 46kV / mm; UV-LED surface drying 4s, complete curing 11s, shaded area complete curing 22h; pencil hardness 4H, impact strength 52kg·cm; QUV UV aging 1000h performance retention rate 92%; viscosity at 25℃ 850mPa·s, solid content 99.0%.

[0048] Example 4

[0049] In a four-necked flask equipped with a stirrer, condenser, and dropping funnel, organosilicon oligomers (specifically polymethylhydrosiloxane, molecular weight 1000~1200), 2-vinylimidazolium, and glycidyl methacrylate (GMA, purity ≥99%) were added in a molar ratio of 1:0.3:0.5. Then, azobisisobutyronitrile (AIBN, purity ≥98%) was added at 0.5% of the total mass of the three monomers. The mixture was reacted at 80°C for 5 hours under nitrogen protection, and then cooled to room temperature to obtain imidazole heterocyclic-epoxy bifunctional modified silicone-acrylic resin with a solid content of 99% and a viscosity of 610 mPa·s at 25°C. A silane coupling agent (specifically KH560, γ-glycidyl etheroxypropyltrimethoxysilane) and a phosphate monomer (specifically 2-hydroxyethyl methacrylate phosphate, abbreviated as P-2M) were mixed at a mass ratio of 2:1 and reacted at 60°C for 2 hours to obtain a core layer prepolymer. Then, 36 parts of acrylate monomers (a mixture of methyl methacrylate (specifically MMA, purity ≥99%) and butyl acrylate (specifically BA, purity ≥99%) at a mass ratio of 1:1) and 0.8% of the total mass of the reaction system of initiator azobisisobutyronitrile (specifically AIBN, purity ≥98%) were added, and the mixture was heated to 80°C and reacted for 3 hours to form a core-shell structure. After cooling, an adhesion promoter was obtained. The high-speed stirring tank was set to a speed of 800 r / min. 70 parts of imidazole heterocyclic-epoxy bifunctional modified silicone-acrylic resin, 9 parts of free radical UV curing agent (specifically TMPTA), 3 parts of cationic curing agent (specifically EPG), 5 parts of adhesion promoter, and 3 parts of photoinitiator (benzyl dimethyl ketal (specifically BDMBK, purity ≥98%) and triaryl sulfonium salt (specifically triphenylthionium hexafluorophosphate)) were added sequentially. After stirring for 30 min, 3 parts of functional additives were added (0.5 parts of defoamer (specifically silicone defoamer, model BYK-054), 1 part of leveling agent (specifically acrylate leveling agent, model BYK-333), and 1.5 parts of antioxidant (specifically hindered phenolic antioxidant, model 1010)). Stirring was continued for 20 min. The mixture was then filtered through a 300-mesh filter to obtain a high-adhesion UV-resistant insulating resin.

[0050] The obtained resin was subjected to performance testing, and the core test results are as follows: adhesion to PCB copper foil was grade 0, adhesion to FR-4 substrate was grade 1, and adhesion to engineering plastic substrate was grade 1; after boiling in water at 100℃ for 2 hours, the adhesion remained at grade 0 with no peeling; after 300 cycles of thermal shock from -40℃ to 125℃, the coating showed no cracking; the volume resistivity was 6×10⁻⁶. 14 Ω·cm, dielectric strength 34kV / mm; UV-LED surface drying 4s, complete curing 11s, shaded area complete curing 22h; pencil hardness 4H, impact strength 51kg·cm; QUV UV aging 1000h performance retention rate 91%; viscosity at 25℃ 860mPa·s, solid content 99.0%.

[0051] Example 5

[0052] In a four-necked flask equipped with a stirrer, condenser, and dropping funnel, an organosilicon oligomer (specifically polymethylhydrosiloxane, molecular weight 1000~1200), a pyridine heterocyclic monomer (specifically 4-vinylpyridine), and glycidyl methacrylate (specifically GMA, purity ≥99%) were added in a molar ratio of 1:0.3:0.5. Then, azobisisobutyronitrile (specifically AIBN, purity ≥98%) was added at 0.5% of the total mass of the three monomers. Under nitrogen protection, the reaction was carried out at a constant temperature of 80°C for 5 hours, and then cooled to room temperature to obtain a pyridine heterocyclic-epoxy bifunctional modified silicone-acrylic resin with a solid content of 99% and a viscosity of 590 mPa·s at 25°C. A silane coupling agent (specifically KH560, γ-glycidyl etheroxypropyltrimethoxysilane) and a phosphate monomer (specifically 2-hydroxyethyl methacrylate phosphate, abbreviated as P-2M) were mixed at a mass ratio of 2:1 and reacted at 60°C for 2 hours to obtain a core layer prepolymer. Then, 36 parts of acrylate monomers (a mixture of methyl methacrylate (specifically MMA, purity ≥99%) and butyl acrylate (specifically BA, purity ≥99%) at a mass ratio of 1:1) and 0.8% of the total mass of the reaction system of initiator azobisisobutyronitrile (specifically AIBN, purity ≥98%) were added, and the mixture was heated to 80°C and reacted for 3 hours to form a core-shell structure. After cooling, an adhesion promoter was obtained. The high-speed stirring tank was set to a speed of 800 r / min. 70 parts of pyridine heterocyclic-epoxy bifunctional modified silicone-acrylic resin, 9 parts of free radical UV curing agent (specifically TMPTA), 3 parts of cationic curing agent (specifically EPG), 5 parts of adhesion promoter, and 3 parts of photoinitiator (benzyl dimethyl ketal (specifically BDMBK, purity ≥98%) and triaryl sulfonium salt (specifically triphenylthionium hexafluorophosphate)) were added sequentially. After stirring for 30 min, 3 parts of functional additives were added (0.5 parts of defoamer (specifically silicone defoamer, model BYK-054), 1 part of leveling agent (specifically acrylate leveling agent, model BYK-333), and 1.5 parts of antioxidant (specifically hindered phenolic antioxidant, model 1010)). Stirring was continued for 20 min. The mixture was then filtered through a 300-mesh filter to obtain a high-adhesion UV-resistant insulating resin.

[0053] The obtained resin underwent performance testing, and the core test results are as follows: adhesion to PCB copper foil was grade 0, adhesion to FR-4 substrate was grade 1, and adhesion to engineering plastic substrate was grade 1; after boiling in water at 100℃ for 2 hours, the adhesion remained at grade 0 with no peeling; after 300 cycles of thermal shock from -40℃ to 125℃, the coating showed no cracking; the volume resistivity was 5.8 × 10⁻⁶. 14Ω·cm, dielectric strength 34kV / mm; UV-LED surface drying 4s, complete curing 12s, shaded area complete curing 22h; pencil hardness 4H, impact strength 52kg·cm; QUV UV aging 1000h performance retention rate 92%; viscosity at 25℃ 840mPa·s, solid content 99.0%.

[0054] Comparative Example 1

[0055] Performance testing was conducted on commercially available conventional silicone-modified UV conformal resins. The core test results are as follows: adhesion to PCB copper foil was grade 2, to FR-4 substrate was grade 1, and to engineering plastic substrate was grade 3; after boiling in water at 100℃ for 2 hours, the adhesion dropped to grade 3, with noticeable peeling; after 300 cycles of thermal shock from -40℃ to 125℃, microcracks appeared in the coating; the volume resistivity was 5×10⁻⁶. 14 Ω·cm, dielectric strength 35kV / mm; UV-LED surface drying 8s, complete curing 20s, shaded area not fully cured 48h; QUV ultraviolet aging 500h shows yellowing, performance retention rate is only 65%; viscosity at 25℃ is 2000mPa·s, poor leveling properties during construction.

[0056] As can be seen from the above embodiments, the present invention provides a high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin and its preparation method. The high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin obtained by the present invention exhibits a cross-cut adhesion rating of 0 on commonly used electronic substrates such as PCB copper foil, FR-4, ABS, PC, and PA6. After being boiled in water at 100℃ for 2 hours, subjected to 500 cycles of thermal shock from -40℃ to 125℃, and subjected to a 5% NaCl salt spray test for 1000 hours, the adhesion remains at a level of 0, with no peeling or flaking, thus solving the problems of poor adhesion and low durability of existing resins. It cures rapidly, with thorough curing in shaded areas: the volume resistivity of the cured coating is ≥10 Ω·cm. 16 Ω·cm, dielectric strength ≥45kV / mm, dielectric constant (1MHz) ≤2.8; after the above environmental aging test, the volume resistivity is still ≥10 Ω·cm. 15With a dielectric strength of Ω·cm and no significant attenuation, its insulation performance is far superior to existing conventional UV conformal resins. It achieves surface drying in 3-5 seconds under UV-LED light, and thick coatings cure completely within 12 seconds. In shaded areas, it fully cures after 24 hours at room temperature, exhibiting no pinholes or microcracks and uniform cross-linking density. It boasts excellent resistance to environmental aging and mechanical properties: the coating has a pencil hardness ≥4H, impact strength ≥50kg·cm, and exhibits no cracking after 100 bending tests (1mm bending radius). After 1000 hours of QUV aging testing, the coating shows no yellowing or chalking, with a performance retention rate ≥90%. It offers excellent workability: the resin viscosity (25℃) is 800~1500mPa·s, allowing for various application methods such as spraying, brushing, and dipping. The coating exhibits good leveling properties and is free of defects such as pinholes and orange peel, meeting the requirements of large-scale industrial production. It is environmentally friendly: the resin system contains no organic solvents, has a solid content ≥98%, and exhibits no VOC emissions during curing, complying with national environmental emission standards.

[0057] The resin of this invention can be widely used in the protection of PCBs and electronic components in consumer electronics, automotive electronics, industrial control and other fields, greatly improving the environmental adaptability and service life of electronic devices, and has significant economic value and market application prospects. At the same time, the preparation process of this invention is simple, the raw materials are readily available, and industrial continuous production can be realized, making it suitable for large-scale promotion and application.

[0058] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin, characterized in that, It is prepared from raw materials containing the following parts by weight: 60-75 parts of heterocyclic modified silicone-acrylic resin, 10-15 parts of UV-cationic composite curing agent, 3-8 parts of adhesion promoter, 2-5 parts of photoinitiator, and 0.5-3 parts of functional additives.

2. The high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin according to claim 1, characterized in that, The heterocyclic modified silicone-acrylic resin is obtained by mixing organosilicon oligomers, nitrogen-containing heterocyclic monomers and glycidyl methacrylate, and reacting them under the action of the initiator azobisisobutyronitrile. The reaction is carried out under nitrogen atmosphere at a temperature of 75-85°C for 4-6 hours.

3. The high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin according to claim 2, characterized in that, The molar ratio of the organosilicon oligomer, the nitrogen-containing heterocyclic monomer, and the glycidyl methacrylate is 1:0.2~0.5:0.5~0.8; The amount of azobisisobutyronitrile added is 0.3~0.5% of the total mass of the reaction system; The nitrogen-containing heterocyclic monomers include one or more of triazine heterocyclic monomers, imidazole heterocyclic monomers, and pyridine heterocyclic monomers.

4. A high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin according to claim 1 or 3, characterized in that, The UV-cationic composite curing agent is obtained by compounding a free radical UV curing agent and a cationic curing agent at a mass ratio of 2 to 3:

1.

5. The high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin according to claim 4, characterized in that, The adhesion promoter is obtained by prepolymerizing a mixture of silane coupling agent and phosphate monomer to obtain a core layer prepolymer, and then adding acrylate monomer and polymerizing it under the action of an initiator. The prepolymerization temperature is 50~70℃, and the prepolymerization time is 1~3h; The polymerization temperature is 70~90℃, and the polymerization time is 3~4h; The silane coupling agent includes one or more of KH560, KH550 and KH570.

6. The high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin according to claim 5, characterized in that, The mass ratio of the silane coupling agent to the phosphate monomer is 2:1~2; The amount of acrylate monomer added is 1 to 1.5 times the total mass of the silane coupling agent and the phosphate monomer, and the amount of initiator added is 0.8 to 1% of the total mass of the reaction system; The acrylate monomer is obtained by compounding methyl methacrylate and butyl acrylate in a mass ratio of 1:1~2; The initiator includes one or more of azobisisobutyronitrile, benzoyl peroxide, and dicumyl peroxide.

7. The high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin according to claim 1, characterized in that, The photoinitiator comprises a compound of hydroxybenzophenone and diphenyliodonium salt in a mass ratio of 2 to 3:1, or a compound of benzyl dimethyl ketal and triaryl sulfonium salt in a mass ratio of 3:

1.

8. The high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin according to claim 1, characterized in that, The functional additive is composed of the following components in parts by weight: 0.1 to 0.5 parts of defoamer, 0.2 to 1 part of leveling agent, and 0.2 to 1.5 parts of antioxidant.

9. A method for preparing the high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin according to any one of claims 1 to 8, characterized in that, Under stirring conditions, heterocyclic modified silicone-acrylic resin, UV-cationic composite curing agent, adhesion promoter and photoinitiator are mixed, functional additives are added, and stirring is continued. After filtration, high adhesion UV three-proof insulating resin is obtained. The heterocyclic modified silicone-acrylic resin has a solid content of ≥99% and a viscosity of 500~800 mPa·s at 25℃. The adhesion promoter has a particle size of 50~100nm.

10. The method for preparing the high-adhesion UV-resistant insulating resin containing heterocyclic modified silicone-acrylic resin according to claim 9, characterized in that, The stirring speed is 800~1000 r / min, and the stirring time is 20~30 min.

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