A weather-resistant multi-curing photosensitive adhesive and a preparation method thereof

Abstract

This invention belongs to the field of photosensitive materials technology, specifically relating to a multi-curing photosensitive adhesive with strong weather resistance and its preparation method. This invention overcomes the limitations of traditional photosensitive adhesives in terms of curing depth and light source compatibility. The oil phase component introduces a fluorosilicone epoxy-polyurethane acrylate composite resin and a multifunctional diluent, integrating epoxy groups, acrylate groups, and siloxane groups on the same molecular chain. Combined with a full-band composite initiator, it achieves rapid response to 365nm UV, 405nm laser, and mercury lamps. Deep cross-linking is achieved through cationic polymerization and moisture condensation, significantly improving adhesion and solvent resistance. The aqueous component uses fluorosilicone-modified polyvinyl alcohol and aminofluorosilicone-modified polyvinyl acetate as amphiphilic emulsifying stabilizers, combined with a gradient emulsification process to form a stable oil-in-water emulsion. Combined with caprolactam-blocked latent curing agents, it achieves long-term storage at room temperature. After heating and unblocking, it cross-links with hydroxyl groups, improving film density and exhibiting ultra-high storage stability and long-lasting weather resistance.

Description

Technical Field

[0001] This invention belongs to the field of photosensitive materials technology, specifically relating to a multi-curing photosensitive adhesive with strong weather resistance and its preparation method. Background Technology

[0002] Photo-thermal dual-curing photosensitive adhesives, with their advantages of complete curing and excellent film performance, are gradually replacing traditional single-curing systems in the high-end printing field. In the existing technology, such as patent CN113406863A, a photo-thermal dual-curing photosensitive adhesive, its preparation method and usage method are disclosed. Through the synergistic effect of photo-initiated crosslinking and hydroxy-isocyanate thermal crosslinking, the adhesion and printing durability of the film layer are effectively improved, which provides a good reference for the research and development of high-performance photosensitive adhesives. However, this technology still has the following technical bottlenecks in practical applications: (1) Limitations of the curing system: It only relies on photo-thermal dual curing, and some deep or shaded areas are not fully cured, resulting in insufficient film crosslinking density; (2) Single light source compatibility: The photoinitiator is only for ultraviolet light. (2) Optimization of light source, low response efficiency to new single-wavelength light sources such as 405nm laser and 365nm LED; (3) Insufficient storage stability: the isocyanate groups in the components are easily hydrolyzed, and the storage period after mixing the two components is short (≤1 week), requiring strict humidity control for storage; (4) Insufficient film resistance: insufficient resistance to strong solvents (such as acetone, cyclohexanone) and high-temperature reflow soldering (150-200℃), limiting its application in high-end electronic fields; (5) Complex preparation process: requires multi-step gradient dispersion, with a dispersion time of up to 20-100min, resulting in low industrial production efficiency.

[0003] It is evident that existing photosensitive adhesives with dual curing properties (photo-thermal) still have significant shortcomings in terms of curing depth, light source compatibility, storage stability, film weather resistance, and preparation efficiency. There is an urgent need to develop a new type of photosensitive adhesive that has more complete curing, wider light source compatibility, storage stability, excellent film resistance, and high preparation efficiency. Summary of the Invention

[0004] The purpose of this invention is to address existing problems by providing a multi-curing photosensitive adhesive with strong weather resistance and its preparation method.

[0005] This invention is achieved through the following technical solution: A multi-curing photosensitive adhesive with strong weather resistance, wherein the photosensitive adhesive is an oil-in-water emulsion with functional aqueous component B as the continuous phase and fluorosilicone modified oily component A as the dispersed phase; The fluorosilicone modified oily component A, by mass percentage, is composed of the following raw materials: 15-30% multifunctional reactive diluent, 3-8% full-band composite initiator, 2-5% promoting latent curing agent, 0.5-2% composite anti-aging and anti-hydrolysis agent, and the balance is fluorosilicone epoxy-polyurethane acrylate composite resin. The functional water-based component B, by mass percentage, consists of the following raw materials: 6-18% fluorosilicone modified polyvinyl alcohol polymer, 4-12% aminofluorosilicone modified polyvinyl acetate resin, 0.3-3% weather-resistant composite additive, and the balance being deionized water.

[0006] Furthermore, the mass ratio of the fluorosilicone modified oily component A, the functional watery component B, and the deionized water is 1:(1.2~2.0):(0.3~1.0).

[0007] Further, the preparation method of the fluorosilicone epoxy-polyurethane acrylate composite resin is as follows: epoxy acrylate, polyurethane acrylate and γ-methacryloyloxypropyltrimethoxysilane are mixed in a mass ratio of 3:2:0.5, and 0.1~0.3% of dibutyltin dilaurate as a catalyst is added to the mixture. The mixture is stirred and reacted at 60~70℃ and 500~600rpm for 3~4h. After the reaction is completed, the temperature is lowered to room temperature to obtain a composite resin containing epoxy groups (cationically cured), acrylate groups (free radical cured) and hydrolyzable siloxane groups.

[0008] Furthermore, the multifunctional reactive diluent is composed of pentaerythritol tetraacrylate, trimethylolpropane triacrylate phosphate, N-vinylcaprolactam, and 3,4-epoxycyclohexyl methacrylate as a free radical-cationic hybrid crosslinking point in a mass ratio of 4:3:2:1. The full-band composite initiator is composed of α-hydroxy ketone photoinitiator 184, free radical initiator TPO, cationic initiator diphenyliodonium hexafluorophosphate, and visible light initiator 2,4-diethylthioxanthone in a mass ratio of 2:1:1:0.5. Among them, the α-hydroxy ketone photoinitiator 184 has a purity ≥98%; the free radical initiator TPO has a purity ≥98%; the cationic initiator diphenyliodonium hexafluorophosphate has a purity ≥99%; and the visible light initiator 2,4-diethylthioxanone (DETX) has a purity ≥98%. The promoting latent curing agent is composed of caprolactam-blocked toluene diisocyanate and organic urea accelerator in a mass ratio of 5:1. The specific preparation method of caprolactam-blocked toluene diisocyanate is as follows: Toluene diisocyanate (TDI) and caprolactam are mixed at a mass ratio of 1:1.2, and 0.1-0.2% of dibutyltin dilaurate as a catalyst is added to the mixture. The mixture is stirred and reacted at 70-80℃ and 400-500rpm for 120-150min. After the reaction is completed, the mixture is cooled to room temperature to obtain a white powder of caprolactam-blocked toluene diisocyanate. The organic urea promoter is Azken UR500 from Germany, with a purity ≥99%.

[0009] Furthermore, the composite anti-aging and anti-hydrolysis agent is composed of carbodiimide compounds and hindered phenolic antioxidant 1010 mixed in a mass ratio of 3:1, and is used to synergistically inhibit photo-oxidative degradation and hydrolytic aging. The carbodiimide compound is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC hydrochloride).

[0010] Further, the preparation method of the fluorosilicone modified polyvinyl alcohol polymer is as follows: polyvinyl alcohol and trifluoropropyltrimethoxysilane are mixed at a mass ratio of 10:1, deionized water (the amount is 2 to 3 times the total mass of the mixed raw materials) is added, and 0.2 to 0.4% of hydrochloric acid as a catalyst is added as a catalyst. The pH value of the system is adjusted to 3.0 to 4.0, and the reaction is stirred at 85 to 90°C and 800 to 1000 rpm for 4 to 5 hours. After the reaction is completed, excess water is removed by vacuum distillation, and the product is dried to constant weight. The degree of alcoholysis of the polyvinyl alcohol is 88-92 mol%, and the degree of polymerization is 2000-3000. The fluorosilicone-modified polyvinyl alcohol polymer has an amphiphilic structure. Its hydrophobic fluorosilane side chains are compatible with the oily component A, and its hydrophilic polyvinyl alcohol backbone is compatible with the aqueous phase, thereby forming a stable interfacial film at the oil-water interface, which has both emulsification and colloidal protection functions.

[0011] Furthermore, the preparation method of the amino-fluorosilicone modified polyvinyl acetate resin is as follows: using polyvinyl acetate resin as the base material, γ-aminotriethoxysilane and trifluoropropyltrimethoxysilane are added in a mass ratio of 10:1:0.8, and 0.1~0.2% of stannous octoate as a catalyst is added as a total mass of the mixed raw materials. The mixture is stirred and reacted at 80~90℃ and 500~700rpm for 2~3h, and then cooled to obtain the product.

[0012] Furthermore, the weather-resistant composite additive is composed of modified nano-reinforcing agent, water-based acrylate leveling agent, isothiazolinone preservative, and composite light stabilizer mixed in a mass ratio of 3:2:1:2. The modified nano-reinforcing agent is a 1:1 mixture of fluorosilane-modified nano-silica and modified nano-titanium dioxide. The modification method of fluorosilane-modified nano-silica is as follows: nano-silica (native size 20nm, purity 99%) is dispersed in anhydrous ethanol (dispersion concentration 10~15mg / mL), 5~8% by weight of epoxy silane coupling agent KH-560 (purity ≥98%) is added, ultrasonically dispersed for 15~20min (ultrasonic power 200~300W), stirred and reacted at 60~70℃ and 300~400rpm for 2~3h, centrifuged (speed 3000~4000rpm, centrifugation time 10~15min), and dried at 80~90℃ for 2~3h to constant weight to obtain fluorosilane-modified nano-silica. The modification method of modified nano-titanium dioxide is as follows: anatase nano-titanium dioxide (particle size 20~50nm, purity ≥99%) is dispersed in deionized water (dispersion concentration 8~12mg / mL), 3~5% by weight of nano-titanium dioxide of silane coupling agent KH570 (purity ≥98%) is added, the pH value of the system is adjusted to 5.0~6.0 with dilute hydrochloric acid, and the reaction is stirred at 70~80℃ and 400~500rpm for 1.5~2h. After the reaction is completed, the mixture is dried at 100~110℃ for 3~4h to constant weight to obtain modified nano-titanium dioxide; The water-based acrylate leveling agent is BYK-333 (purity ≥99%), and the isothiazolinone preservative is MIT-100 (active ingredient content ≥99%). The composite light stabilizer is a 1:1 mixture of UV absorber UV-531 (purity ≥98%) and hindered amine light stabilizer HS-944 (purity ≥98%).

[0013] A method for preparing the aforementioned weather-resistant, multi-curing photosensitive adhesive, comprising a gradient emulsification dispersion process, using a polymeric emulsifying stabilizer in functional aqueous component B to encapsulate and stabilize fluorosilicone-modified oily component A, including the following steps: S1. Preparation of fluorosilicone modified oily component A: Weigh out each raw material of component A according to the proportion, stir and mix at 50~60℃ and 700~900rpm for 10~20min, and cool to room temperature for later use; S2. Preparation of functional aqueous component B (preparation of polymeric emulsion stabilizer solution): Weigh each raw material of component B according to the proportion, add the fluorosilicone modified polyvinyl alcohol polymer to deionized water, and stir at high speed at 80~90℃ and 1100~1300rpm for 30~40min until completely dissolved to obtain a uniform colloidal solution; after cooling to 40~45℃, add amino fluorosilicone modified polyvinyl acetate resin and other components, and stir at 500~700rpm for 10~20min to obtain functional water-based component B; S3, Complex Dispersion and Emulsion Formation: Under high-speed dispersion conditions, the fluorosilicone modified oily component A is slowly added dropwise to the functional aqueous component B at a rate of 5-8 mL / min. After the addition is complete, the mixture is pre-emulsified and dispersed at 1000-2000 rpm for 5-8 min. Then, half of the formulation amount of deionized water is added to adjust the viscosity of the system. Next, the mixture is further dispersed for 10-15 min using a synergistic treatment method of high-speed shearing at 2000-3000 rpm and ultrasonic dispersion at 40 kHz, so that the oil phase is fully broken up and stably coated by the polymer emulsifier to form a uniform and delicate emulsion. S4. Viscosity Adjustment Filtration: Add the remaining deionized water to adjust to the specified viscosity, stir at 1100~1300 rpm for 3~7 min, and filter through a single layer of 400 mesh polyester wire mesh to obtain the finished photosensitive emulsion.

[0014] The present invention has the following advantages over the prior art: 1. This invention provides a weather-resistant multi-curing photosensitive adhesive and its preparation method, fundamentally breaking through the limitations of traditional photosensitive adhesives in terms of curing depth and light source compatibility. Its core lies in the introduction of a fluorosilicone epoxy-polyurethane acrylate composite resin and a multifunctional reactive diluent into the oily component A. The former integrates epoxy groups, acrylate groups and hydrolyzable siloxane groups on the same molecular chain, while the latter contains multifunctional diluents such as pentaerythritol tetraacrylate and a hybrid crosslinking point of 3,4-epoxycyclohexyl methacrylate. The system utilizes a full-spectrum composite initiator composed of oxime esters, TPO, diphenyliodonium hexafluorophosphate, and the visible light initiator 2,4-diethylthioxanthone. This enables the system to respond rapidly to the full spectrum of 365nm UV, 405nm laser, and mercury lamp light. Furthermore, it can continuously crosslink in deep or shadowed areas through cationic-initiated post-polymerization and moisture condensation of siloxanes. This multi-curing mechanism ensures that the film can form a high-density three-dimensional network structure both on the surface and deep within the film, thereby significantly improving adhesion, cohesive strength, and solvent resistance.

[0015] 2. The fluorosilicone-modified polyvinyl alcohol polymer of the present invention is compatible with the oily component A through its hydrophobic side chains, while the hydrophilic backbone extends out to form a tough interfacial film at the oil-water interface. The introduction of amino-fluorosilicone-modified polyvinyl acetate resin further enhances the mechanical strength and compatibility of the interfacial layer. Combined with a gradient emulsification dispersion process, the oil phase is uniformly broken down and stably coated, forming a fine oil-in-water emulsion. Furthermore, toluene diisocyanate blocked with caprolactam is used as a latent curing agent in component A, which remains blocked and does not react with moisture during room temperature storage, ensuring the storage stability of the emulsion.

[0016] 3. This invention achieves performance maintenance of the film layer under harsh environments through multi-dimensional anti-aging design. The carbodiimide compound in the composite anti-aging hydrolysate effectively captures the carboxylic acid produced by hydrolysis, blocking the autocatalytic degradation of the resin, while the hindered phenolic antioxidant 1010 quenches free radicals and inhibits thermo-oxidative aging. The fluorosilane-modified nano-silica and modified nano-titanium dioxide in the weather-resistant composite additive not only enhance the film layer's density by filling defects through nano-effects, but also endow the coating with excellent UV shielding ability and low surface energy characteristics, significantly delaying photo-oxidative aging and yellowing. At the same time, the introduction of fluorosilicone elements into the entire system greatly reduces the surface energy of the film layer, giving it excellent water-repellent, oil-repellent, and anti-fouling properties, synergistically improving durability under high temperature and humidity, strong UV radiation, and chemical corrosion environments. Detailed Implementation

[0017] To further explain the present invention, the following specific embodiments are described.

[0018] Note: Unless otherwise specified, the raw materials used in this invention are all from commercially available conventional products.

[0019] The preparation method of fluorosilicone epoxy-polyurethane acrylate composite resin is as follows: epoxy acrylate, polyurethane acrylate and γ-methacryloyloxypropyltrimethoxysilane are mixed in a mass ratio of 3:2:0.5. Dibutyltin dilaurate is added as a catalyst at 0.2% of the total mass of the mixed raw materials. The mixture is stirred and reacted at 65℃ and 550rpm for 3.5h. After the reaction is completed, the temperature is lowered to room temperature to obtain a composite resin containing epoxy groups (cationically cured), acrylate groups (free radical cured) and hydrolyzable siloxane groups.

[0020] The multifunctional reactive diluent is composed of pentaerythritol tetraacrylate, trimethylolpropane triacrylate phosphate, N-vinylcaprolactam, and 3,4-epoxycyclohexyl methacrylate as a free radical-cationic hybrid crosslinking point in a mass ratio of 4:3:2:1.

[0021] The full-band composite initiator is composed of α-hydroxy ketone photoinitiator 184, free radical initiator TPO, cationic initiator diphenyliodonium hexafluorophosphate, and visible light initiator 2,4-diethylthioxanthone in a mass ratio of 2:1:1:0.5. The α-hydroxy ketone photoinitiator 184 has a CAS number of 947-19-3 and a purity of ≥98%; the free radical initiator TPO has a purity of ≥98%; the cationic initiator diphenyliodonium hexafluorophosphate has a purity of ≥99%; and the visible light initiator 2,4-diethylthioxanone (DETX) has a purity of ≥98%.

[0022] The accelerator-type latent curing agent is composed of caprolactam-blocked toluene diisocyanate and organic urea accelerator in a mass ratio of 5:1. The specific preparation method of caprolactam-blocked toluene diisocyanate is as follows: Toluene diisocyanate (TDI) and caprolactam are mixed at a mass ratio of 1:1.2, and 0.15% of dibutyltin dilaurate as a catalyst is added to the mixture. The mixture is stirred and reacted at 75℃ and 450rpm for 135min. After the reaction is completed, the mixture is cooled to room temperature to obtain a white powder of caprolactam-blocked toluene diisocyanate. The organic urea promoter is Azken UR500 from Germany, CAS No. 17526-94-2, with a purity ≥99%.

[0023] The composite anti-aging and anti-hydrolysis agent is a mixture of carbodiimide compounds and hindered phenolic antioxidant 1010 in a mass ratio of 3:1, which is used to synergistically inhibit photo-oxidative degradation and hydrolytic aging. The carbodiimide compound is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride (EDC hydrochloride).

[0024] The preparation method of fluorosilicone modified polyvinyl alcohol polymer is as follows: polyvinyl alcohol and trifluoropropyltrimethoxysilane are mixed at a mass ratio of 10:1, deionized water (the amount is 2.5 times the total mass of the mixed raw materials) is added, and hydrochloric acid of 0.3% of the total mass of the mixed raw materials is added as a catalyst to adjust the pH value of the system to 3.5. The reaction is stirred at 90℃ and 900rpm for 4.5h. After the reaction is completed, excess water is removed by vacuum distillation, and the product is dried to constant weight. The fluorosilicone-modified polyvinyl alcohol polymer has an amphiphilic structure. Its hydrophobic fluorosilane side chains are compatible with the oily component A, and its hydrophilic polyvinyl alcohol backbone is compatible with the aqueous phase, thereby forming a stable interfacial film at the oil-water interface, which has both emulsification and colloidal protection functions.

[0025] The preparation method of amino-fluorosilicone modified polyvinyl acetate resin is as follows: using polyvinyl acetate resin as the base material, γ-aminotriethoxysilane and trifluoropropyltrimethoxysilane are added in a mass ratio of 10:1:0.8, and 0.15% of stannous octoate as a catalyst is added as a catalyst. The mixture is stirred and reacted at 85℃ and 600rpm for 2.5h, and then cooled to obtain the final product.

[0026] The weather-resistant composite additive is composed of modified nano-reinforcing agent, water-based acrylate leveling agent, isothiazolinone preservative, and composite light stabilizer mixed in a mass ratio of 3:2:1:2; The modified nano-reinforcing agent is a 1:1 mixture of fluorosilane-modified nano-silica and modified nano-titanium dioxide. The modification method for the fluorosilane-modified nano-silica is as follows: nano-silica (native size 20nm, purity 99%) is dispersed in anhydrous ethanol (dispersion concentration 12mg / mL), and 6% (by weight of the nano-silica) of epoxy silane coupling agent KH-560 (CAS No. 2530-83-8, purity ≥98%) is added. The mixture is ultrasonically dispersed for 15 min (ultrasonic power 200W), stirred at 65℃ and 350rpm for 2.5 h, centrifuged (3500rpm, centrifugation time 15 min), and dried at 85℃ for 2.5 h to constant weight to obtain fluorosilane-modified nano-silica (Fulongqing SF-BKT-002 model, solid content ≥99%) can be directly purchased). The modification method of modified nano-titanium dioxide is as follows: anatase nano-titanium dioxide (particle size 20~50nm, purity ≥99%) is dispersed in deionized water (dispersion concentration is 10mg / mL), 4% by weight of nano-titanium dioxide of silane coupling agent KH570 (CAS No. 988-67-2, purity ≥98%) is added, the pH value of the system is adjusted to 5.5 with dilute hydrochloric acid, and the reaction is stirred at 75℃ and 450rpm for 1.5h. After the reaction is completed, it is dried at 105℃ for 3.5h to constant weight to obtain modified nano-titanium dioxide; The water-based acrylate leveling agent is BYK-333 (purity ≥99%), and the isothiazolinone preservative is MIT-100 (active ingredient content ≥99%). The composite light stabilizer is a 1:1 mixture of UV absorber UV-531 (CAS No. 1843-05-6, purity ≥98%) and hindered amine light stabilizer HS-944 (CAS No. 71878-19-8, purity ≥98%).

[0027] Example 1 A multi-curing photosensitive adhesive with strong weather resistance, wherein the photosensitive adhesive is an oil-in-water emulsion with functional aqueous component B as the continuous phase and fluorosilicone modified oily component A as the dispersed phase; The fluorosilicone modified oily component A is composed of the following raw materials by mass percentage: 15% multifunctional reactive diluent, 3% full-band composite initiator, 2% promoting latent curing agent, 0.5% composite anti-aging and anti-hydrolysis agent, and the balance is fluorosilicone epoxy-polyurethane acrylate composite resin. The functional water-based component B, by mass percentage, consists of the following raw materials: 6% fluorosilicone modified polyvinyl alcohol polymer, 4% aminofluorosilicone modified polyvinyl acetate resin, 0.3% weather-resistant composite additive, and the balance being deionized water. The mass ratio of the fluorosilicone modified oily component A, the functional watery component B, and the deionized water is 1:1.2:0.3.

[0028] The method for preparing the weather-resistant multi-curing photosensitive adhesive involves a gradient emulsification dispersion process, utilizing a polymeric emulsifying stabilizer in the functional aqueous component B to encapsulate and stabilize the fluorosilicone-modified oily component A, and includes the following steps: S1. Preparation of fluorosilicone modified oily component A: Weigh out each raw material of component A according to the proportion, stir and mix at 50℃ and 700rpm for 10min, and cool to room temperature for later use. S2. Preparation of functional aqueous component B (preparation of polymeric emulsion stabilizer solution): Weigh each raw material of component B according to the proportion, add the fluorosilicone modified polyvinyl alcohol polymer to deionized water, and stir at 80℃ and 1100rpm for 30min until completely dissolved to obtain a uniform colloidal solution; after cooling to 40℃, add amino fluorosilicone modified polyvinyl acetate resin and other components, and stir at 500rpm for 10min to obtain functional water-based component B. S3, Complex Dispersion and Emulsion Formation: Under high-speed dispersion conditions, the fluorosilicone modified oily component A was slowly added dropwise to the functional aqueous component B at a rate of 5 mL / min. After the addition was completed, the mixture was pre-emulsified and dispersed at 1000 rpm for 5 min. Then, half of the formulation amount of deionized water was added to adjust the viscosity of the system. Next, the mixture was dispersed for another 10 min using a synergistic treatment method of high-speed shearing at 2000 rpm and ultrasonic dispersion at 40 kHz. This process ensured that the oil phase was fully broken up and stably coated by the polymer emulsifier, forming a uniform and delicate emulsion. S4. Viscosity Adjustment Filtration: Add the remaining deionized water to adjust to the specified viscosity, stir at 1100 rpm for 3 minutes, and filter through a single layer of 400-mesh polyester wire mesh to obtain the finished photosensitive emulsion.

[0029] Example 2 A multi-curing photosensitive adhesive with strong weather resistance, wherein the photosensitive adhesive is an oil-in-water emulsion with functional aqueous component B as the continuous phase and fluorosilicone modified oily component A as the dispersed phase; The fluorosilicone modified oily component A, by mass percentage, is composed of the following raw materials: 18% multifunctional reactive diluent, 6% full-band composite initiator, 3.5% promoting latent curing agent, 1.5% composite anti-aging and anti-hydrolysis agent, and the balance is fluorosilicone epoxy-polyurethane acrylate composite resin. The functional water-based component B, by mass percentage, consists of the following raw materials: 12% fluorosilicone modified polyvinyl alcohol polymer, 8% amino fluorosilicone modified polyvinyl acetate resin, 1.5% weather-resistant composite additive, and the balance being deionized water. The mass ratio of the fluorosilicone modified oily component A, the functional watery component B, and the deionized water is 1:1.6:0.8.

[0030] The method for preparing the weather-resistant multi-curing photosensitive adhesive involves a gradient emulsification dispersion process, utilizing a polymeric emulsifying stabilizer in the functional aqueous component B to encapsulate and stabilize the fluorosilicone-modified oily component A, and includes the following steps: S1. Preparation of fluorosilicone modified oily component A: Weigh out each raw material of component A according to the proportion, stir and mix at 55℃ and 800rpm for 15min, and cool to room temperature for later use. S2. Preparation of functional aqueous component B (preparation of polymeric emulsion stabilizer solution): Weigh each raw material of component B according to the proportion, add the fluorosilicone modified polyvinyl alcohol polymer to deionized water, and stir at 85℃ and 1200rpm for 35min until completely dissolved to obtain a uniform colloidal solution; after cooling to 43℃, add amino fluorosilicone modified polyvinyl acetate resin and other components, and stir at 600rpm for 15min to obtain functional waterborne component B. S3, Complex Dispersion and Emulsion Formation: Under high-speed dispersion conditions, the fluorosilicone modified oily component A was slowly added dropwise to the functional aqueous component B at a rate of 6 mL / min. After the addition was completed, the mixture was pre-emulsified and dispersed at 1500 rpm for 6 min. Then, half of the formulation amount of deionized water was added to adjust the viscosity of the system. Next, the mixture was dispersed for another 12 min using a synergistic treatment method of high-speed shearing at 2500 rpm and ultrasonic dispersion at 40 kHz. This process ensured that the oil phase was fully broken up and stably coated by the polymer emulsifier, forming a uniform and delicate emulsion. S4. Viscosity Adjustment Filtration: Add the remaining deionized water to adjust to the specified viscosity, stir at 1200 rpm for 5 minutes, and filter through a single layer of 400-mesh polyester wire mesh to obtain the finished photosensitive emulsion.

[0031] Example 3 A multi-curing photosensitive adhesive with strong weather resistance, wherein the photosensitive adhesive is an oil-in-water emulsion with functional aqueous component B as the continuous phase and fluorosilicone modified oily component A as the dispersed phase; The fluorosilicone modified oily component A is composed of the following raw materials by mass percentage: 30% multifunctional reactive diluent, 8% full-band composite initiator, 5% promoting latent curing agent, 2% composite anti-aging and anti-hydrolysis agent, and the balance is fluorosilicone epoxy-polyurethane acrylate composite resin. The functional water-based component B, by mass percentage, consists of the following raw materials: 18% fluorosilicone modified polyvinyl alcohol polymer, 12% amino fluorosilicone modified polyvinyl acetate resin, 3% weather-resistant composite additive, and the balance being deionized water. The mass ratio of the fluorosilicone modified oily component A, the functional watery component B, and the deionized water is 1:2.0:1.0.

[0032] The method for preparing the weather-resistant multi-curing photosensitive adhesive involves a gradient emulsification dispersion process, utilizing a polymeric emulsifying stabilizer in the functional aqueous component B to encapsulate and stabilize the fluorosilicone-modified oily component A, and includes the following steps: S1. Preparation of fluorosilicone modified oily component A: Weigh out each raw material of component A according to the proportion, stir and mix at 60℃ and 900rpm for 20min, and cool to room temperature for later use; S2. Preparation of functional aqueous component B (preparation of polymeric emulsion stabilizer solution): Weigh each raw material of component B according to the proportion, add the fluorosilicone modified polyvinyl alcohol polymer to deionized water, and stir at 90℃ and 1300rpm for 40min until completely dissolved to obtain a uniform colloidal solution; after cooling to 45℃, add amino fluorosilicone modified polyvinyl acetate resin and other components, and stir at 700rpm for 20min to obtain functional waterborne component B. S3, Complex Dispersion and Emulsion Formation: Under high-speed dispersion conditions, the fluorosilicone modified oily component A was slowly added dropwise to the functional aqueous component B at a rate of 8 mL / min. After the addition was completed, the mixture was pre-emulsified and dispersed at 2000 rpm for 8 min. Then, half of the formulation amount of deionized water was added to adjust the viscosity of the system. Next, the mixture was dispersed for another 15 min using a synergistic treatment method of high-speed shearing at 3000 rpm and ultrasonic dispersion at 40 kHz. This allowed the oil phase to be fully broken up and stably coated by the polymer emulsifier, forming a uniform and delicate emulsion. S4. Viscosity Adjustment Filtration: Add the remaining deionized water to adjust to the specified viscosity, stir at 1300 rpm for 7 minutes, and filter through a single layer of 400-mesh polyester wire mesh to obtain the finished photosensitive emulsion.

[0033] Comparative Example 1 Compared with Example 2, Comparative Example 1 removes the promoting latent curing agent and replaces it with a common isocyanate curing agent, while other steps and parameters are the same as in Example 2.

[0034] Comparative Example 2 Compared with Example 2, Comparative Example 2 replaces the full-band composite initiator with a single TPO, and has no cationic initiator or visible light initiator. Other steps and parameters are the same as in Example 2.

[0035] Comparative Example 3 Compared with Example 2, Comparative Example 3 replaced the fluorosilicone epoxy-polyurethane acrylate composite resin with epoxy acrylate resin and the fluorosilicone modified polyvinyl alcohol with ordinary PVA. Other steps and parameters were the same as in Example 2.

[0036] Comparative Example 4 Compared with Example 2, Comparative Example 4 removes the composite anti-aging and anti-hydrolysis agent and the weather-resistant composite additive, while the other steps and parameters are the same as in Example 2.

[0037] 1. Performance Testing Curing efficiency: In accordance with the standard GB / T 24148-2009, the curing time and hardness were measured by irradiation with 365nm UV, 405nm laser and mercury lamp respectively; Storage stability: According to the standard GB / T 6753.3-1986, the viscosity change rate and whether stratification occurred were tested after 7 days of constant temperature storage at 50℃. Adhesion: Refer to GB / T 9286-1998, use the cross-cut adhesion test to test the adhesion level of the cured film layer; Solvent resistance: Refer to GB / T 23989-2009, wipe with acetone 50 times, and observe whether the film layer bubbles or peels off; Weather resistance: According to GB / T 1865-2009, the yellowing index ΔE and gloss retention rate were tested after 500 hours in a UV aging chamber. Thermal stability: According to GB / T 1735-2009, bake at 200℃ for 30 minutes and observe the cracking and discoloration of the film.

[0038] 2. Experimental Results The test results are shown in Table 1 below.

[0039] Table 1

[0040] As can be seen from Table 1 above, Example 2 of the present invention is superior to all comparative examples in terms of curing efficiency, storage stability, and adhesion, which verifies the scientificity and practicality of technologies such as full-band photoinitiation, latent thermal curing, fluorosilicone modification, and multiple anti-aging.

[0041] Compared to Example 2, Comparative Example 1 is a traditional photo-thermal dual curing system, which has a slow curing speed, poor storage stability, and is prone to delamination. This may be because it lacks a closed-type latent curing agent, and the isocyanate groups are prone to react with water, resulting in side reactions during storage and causing instability in the system.

[0042] Comparative Example 2 uses a single UV initiation system. Due to the lack of cationic and visible light initiators, it cannot cover the entire wavelength light source. The crosslinking density is low, so it hardly cures the 405nm laser, the deep curing is incomplete, and the weather resistance is poor.

[0043] Comparative Example 3, without fluorinated silicone modification, showed a significant decrease in adhesion, solvent resistance, and weather resistance. This demonstrates that the fluorinated silicone structure of the present invention enhances surface energy and improves stain resistance and water resistance, while the lack of fluorinated silicone modification leads to increased resin hydrophilicity and poor aging resistance.

[0044] Comparative Example 4, lacking anti-aging additives, exhibited severe yellowing, poor thermal stability, and significant film aging. The absence of carbodiimide-based anti-hydrolysis agents and hindered amine light stabilizers prevented effective inhibition of photo-oxidative aging and hydrolysis reactions.

[0045] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A multi-curing photosensitive adhesive with strong weather resistance, characterized in that, The photosensitive emulsion is an oil-in-water emulsion with functional aqueous component B as the continuous phase and fluorosilicone modified oily component A as the dispersed phase. The fluorosilicone modified oily component A, by mass percentage, is composed of the following raw materials: 15-30% multifunctional reactive diluent, 3-8% full-band composite initiator, 2-5% promoting latent curing agent, 0.5-2% composite anti-aging and anti-hydrolysis agent, and the balance is fluorosilicone epoxy-polyurethane acrylate composite resin. The functional water-based component B, by mass percentage, consists of the following raw materials: 6-18% fluorosilicone modified polyvinyl alcohol polymer, 4-12% aminofluorosilicone modified polyvinyl acetate resin, 0.3-3% weather-resistant composite additive, and the balance being deionized water.

2. The weather-resistant, multi-curing photosensitive adhesive according to claim 1, characterized in that, The mass ratio of the fluorosilicone modified oily component A, the functional watery component B, and the deionized water is 1:(1.2~2.0):(0.3~1.0).

3. The weather-resistant, multi-curing photosensitive adhesive according to claim 1, characterized in that, The preparation method of the fluorosilicone epoxy-polyurethane acrylate composite resin is as follows: epoxy acrylate, polyurethane acrylate and γ-methacryloyloxypropyltrimethoxysilane are mixed in a mass ratio of 3:2:0.5, and 0.1~0.3% of dibutyltin dilaurate as a catalyst is added to the mixture. The mixture is stirred and reacted at 60~70℃ and 500~600rpm for 3~4h. After the reaction is completed, the temperature is lowered to room temperature.

4. The weather-resistant, multi-curing photosensitive adhesive according to claim 1, characterized in that, The multifunctional reactive diluent is composed of pentaerythritol tetraacrylate, trimethylolpropane triacrylate phosphate, N-vinylcaprolactam and 3,4-epoxycyclohexyl methacrylate in a mass ratio of 4:3:2:

1. The full-band composite initiator is composed of α-hydroxy ketone photoinitiator 184, free radical initiator TPO, cationic initiator diphenyliodonium hexafluorophosphate, and visible light initiator 2,4-diethylthioxanthone in a mass ratio of 2:1:1:0.

5. The promoting latent curing agent is a compound of caprolactam-blocked toluene diisocyanate and organic urea accelerator in a mass ratio of 5:

1.

5. The weather-resistant, multi-curing photosensitive adhesive according to claim 1, characterized in that, The composite anti-aging and anti-hydrolysis agent is composed of carbodiimide compounds and hindered phenolic antioxidant 1010 in a mass ratio of 3:

1. The carbodiimide compound is 1-ethyl-(3-dimethylaminopropyl)carbodiimide hydrochloride.

6. The weather-resistant, multi-curing photosensitive adhesive according to claim 1, characterized in that, The preparation method of the fluorosilicone modified polyvinyl alcohol polymer is as follows: polyvinyl alcohol and trifluoropropyltrimethoxysilane are mixed at a mass ratio of 10:1, deionized water is added, and 0.2~0.4% of hydrochloric acid as a catalyst is added to the total mass of the mixed raw materials. The pH value of the system is adjusted to 3.0~4.0, and the reaction is stirred at 85~90℃ and 800~1000rpm for 4~5h. After the reaction is completed, excess water is removed by vacuum distillation, and the product is dried to constant weight. The degree of alcoholysis of the polyvinyl alcohol is 88-92 mol%, and the degree of polymerization is 2000-3000.

7. The weather-resistant, multi-curing photosensitive adhesive according to claim 1, characterized in that, The preparation method of the amino-fluorosilicone modified polyvinyl acetate resin is as follows: using polyvinyl acetate resin as the base material, γ-aminotriethoxysilane and trifluoropropyltrimethoxysilane are added in a mass ratio of 10:1:0.8, and 0.1~0.2% of stannous octoate as a catalyst is added as a total mass of the mixed raw materials. The mixture is stirred and reacted at 80~90℃ and 500~700rpm for 2~3h, and then cooled to obtain the product.

8. The weather-resistant, multi-curing photosensitive adhesive according to claim 1, characterized in that, The weather-resistant composite additive is composed of modified nano-reinforcing agent, water-based acrylate leveling agent, isothiazolinone preservative, and composite light stabilizer mixed in a mass ratio of 3:2:1:

2.

9. The weather-resistant, multi-curing photosensitive adhesive according to claim 8, characterized in that, The modified nano-reinforcing agent is a 1:1 mixture of fluorosilane-modified nano-silica and modified nano-titanium dioxide. The composite light stabilizer is a mixture of UV absorber UV-531 and hindered amine light stabilizer HS-944 in a 1:1 ratio.

10. A method for preparing a weather-resistant, multi-curing photosensitive adhesive as described in any one of claims 1 to 9, characterized in that, The fluorosilicone-modified oily component A is encapsulated and stabilized using a gradient emulsification dispersion process, utilizing a high-molecular-weight emulsifying stabilizer in functional aqueous component B, including the following steps: S1. Preparation of fluorosilicone modified oily component A: Weigh out each raw material of component A according to the proportion, stir and mix at 50~60℃ and 700~900rpm for 10~20min, and cool to room temperature for later use; S2. Preparation of functional aqueous component B: Weigh each raw material of component B according to the proportion, add the fluorosilicone modified polyvinyl alcohol polymer to deionized water, and stir at high speed at 80~90℃ and 1100~1300rpm for 30~40min until dissolved to obtain a uniform colloidal solution; after cooling to 40~45℃, add amino fluorosilicone modified polyvinyl acetate resin and other components, and stir at 500~700rpm for 10~20min to obtain functional water-based component B; S3, Complex Dispersion and Emulsion Formation: Under high-speed dispersion conditions, the fluorosilicone modified oily component A is slowly added dropwise to the functional aqueous component B at a rate of 5-8 mL / min. After the addition is complete, the mixture is pre-emulsified and dispersed at 1000-2000 rpm for 5-8 min. Then, half of the formulation amount of deionized water is added to adjust the viscosity of the system. Next, the mixture is further dispersed for 10-15 min using a synergistic treatment method of high-speed shearing at 2000-3000 rpm and ultrasonic dispersion at 40 kHz, so that the oil phase is fully broken up and stably coated by the polymer emulsifier to form a uniform and delicate emulsion. S4. Viscosity Adjustment Filtration: Add the remaining deionized water to adjust to the specified viscosity, stir at 1100~1300 rpm for 3~7 min, and filter through a single layer of 400 mesh polyester wire mesh to obtain the finished photosensitive emulsion.

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