Double crosslinking regulated uv adhesion-reducing film for utg processing and preparation method thereof

Abstract

This invention relates to the field of UV anti-adhesion film preparation technology, specifically to a UV anti-adhesion film for UTG processing with dual crosslinking control and its preparation method. It consists of a modified PO base film and a composite adhesive layer. The modified PO base film is a polyethylene-polypropylene blend modified polyolefin film. The composite adhesive layer contains a fluorinated modified polyurethane acrylate prepolymer, a multifunctional UV monomer, a composite photoinitiator, and a dual interface modifier. The mass percentages of each component are 38-45%, 42-48%, 3-5%, and 2-4%, respectively. The multifunctional UV monomer is a mixture of TMPTA and HDDA at a mass ratio of 1:1.2. This invention optimizes the adhesive layer formulation and base film pretreatment process, improving etch resistance and interfacial compatibility, achieving precise matching of peel force before and after UV treatment, resulting in a product with low thermal shrinkage, minimal adhesive residue, and reduced glass damage. It significantly improves the yield of UTG thinning and is suitable for large-scale processing of flexible electronics.

Description

Technical Field

[0001] This invention relates to the field of UV anti-adhesion film preparation technology, specifically to a UV anti-adhesion film for dual crosslinking-controlled UTG processing and its preparation method. Background Technology

[0002] With the rapid popularization of flexible electronic terminals such as foldable screens and wearable devices, UTG, as a core flexible substrate, has become a focal point of industry competition in terms of its large-scale processing technology. UV photopolymer anti-adhesion film, as a key supporting material in the chemical thinning and physical grinding processes of UTG, undertakes the core functions of temporary substrate fixation, surface corrosion protection, and precise peeling after etching. Its performance directly determines the processing yield, dimensional accuracy, and surface quality of UTG products. Leveraging the lightweight and low-cost advantages of PO original film, PO-based UV anti-adhesion film has become the mainstream choice for UTG processing materials. However, existing products have not been specifically optimized for the demanding process environment of UTG thinning, resulting in numerous technical bottlenecks.

[0003] The core defects of existing PO-based UV anti-adhesion films are concentrated in four aspects: First, insufficient chemical corrosion resistance. The hydrofluoric acid / nitric acid etching system commonly used for UTG thinning has strong oxidizing and corrosive properties. Traditional PO films and adhesive layers are prone to swelling and degradation, leading to interfacial peeling and causing UTG glass to lose effective fixation. Second, unbalanced interfacial compatibility. The surface of the PO film is inert, and the adhesion to the adhesive layer is weak. Before UV irradiation, the peeling force is insufficient, and the substrate is prone to displacement during the etching process. After UV irradiation, the adhesion between the adhesive layer and the glass substrate is difficult to reduce effectively, resulting in edge cracking and surface scratches of the ultra-thin glass. Third, poor thermal stability. The 80-100℃ drying process in UTG processing will cause significant thermal shrinkage of the traditional PO film, which will lead to UTG glass warping and affect the dimensional accuracy of the product. Fourth, prominent residual adhesive problem. The adhesive layer formulation is not reasonably designed, and after peeling, an adhesive layer is easily left on the glass surface, reducing the glass transmittance and surface flatness, seriously affecting the performance of the end product.

[0004] Current industry technology shows that existing UV anti-adhesion films mostly use general-purpose formulations and processes, failing to fully consider the differences in interface characteristics between the PO base film and the glass substrate, and neglecting optimization for key factors such as the corrosiveness of the etching environment and the thermal stress of the drying process. As UTG glass becomes thinner and more flexible, the performance requirements for anti-adhesion films are becoming increasingly stringent. They not only need to achieve high adhesion strength and damage-free peeling, but also excellent corrosion resistance, low shrinkage, and low residue. Therefore, developing a high-performance product that meets the needs of large-scale UTG processing and addresses many of the technical pain points of existing PO-based UV anti-adhesion films is crucial for promoting the development of the flexible electronics industry and is of great significance for reducing UTG processing costs and enhancing product competitiveness. Summary of the Invention

[0005] (a) Technical problems to be solved To address the shortcomings of existing PO-based UV anti-adhesion films, such as poor etch resistance, unbalanced interfacial compatibility, high thermal shrinkage, high residual adhesive rate, and difficulty in accurately matching peeling forces before and after UV treatment, this invention provides a UV anti-adhesion film for UTG processing with dual crosslinking control and its preparation method.

[0006] (II) Technical Solution The UV photo-induced anti-adhesion film for thinning UTG glass using PO base film consists of a modified PO base film and a composite adhesive layer. The modified PO base film is a polyethylene-polypropylene blend modified polyolefin film, and the composite adhesive layer contains a fluorinated polyurethane acrylate prepolymer, a multifunctional UV monomer, a composite photoinitiator, and a dual-interface modifier.

[0007] Furthermore, the components of the composite adhesive layer are compounded according to the following mass ratios: 38-45% fluorine-modified polyurethane acrylate prepolymer, 42-48% multifunctional UV monomer, 3-5% composite photoinitiator, and 2-4% dual-interface modifier; The multifunctional UV monomer is a synergistic system of trimethylolpropane triacrylate (TMPTA) and 1,6-hexanediol diacrylate (HDDA) in a mass ratio of 1:1.2. This compounding ratio can balance the curing rate and flexibility of the adhesive layer. TMPTA provides high crosslinking density to ensure structural stability, while HDDA optimizes molecular chain flexibility to avoid brittleness after curing. The synergistic effect of the two enables the adhesive layer to maintain good mechanical properties before and after UV irradiation, making it suitable for complex process environments such as etching and drying in the UTG glass thinning process.

[0008] Furthermore, the thickness of the modified PO primary film is strictly controlled within 60-150 μm. This thickness range ensures the film's supporting strength, preventing displacement of the UTG glass during processing, while also avoiding stress concentration due to excessive thickness caused by thermal shrinkage. The composite adhesive layer thickness is 10-40 μm, precisely matched to the surface roughness of the UTG glass and the etching process requirements, ensuring sufficient contact and stable adhesion between the adhesive layer and the glass substrate. The peel force before UV irradiation is 12-26 N / 25 mm. This peel force firmly fixes the UTG glass, meeting the fixation requirements during chemical etching and physical grinding processes, and preventing substrate displacement. Processing defects caused by position; after UV irradiation, the peel force is reduced to 0.05-0.3N / 25mm, achieving damage-free peeling and preventing edge cracking and surface scratches of ultra-thin glass; it is resistant to swelling and degradation after immersion in hydrofluoric acid / nitric acid etching solution (volume ratio 3:1) for 2 hours, resisting the strong corrosive effect of the etching solution and ensuring the continuous effectiveness of the fixing function; the residual adhesive rate is <0.04%, avoiding residual adhesive from affecting the light transmittance and surface flatness of UTG glass; the modified PO original film has a shrinkage rate ≤0.1% under drying conditions of 80-100℃, which can effectively control the warpage of UTG glass and ensure the dimensional accuracy and performance of the processed glass.

[0009] Furthermore, the dual-interface modifier is a polyurethane compound system. This system, through molecular structure design, possesses both oleophilic and hydrophilic functional groups. The oleophilic functional groups can form a strong bond with the inert PO original film surface, while the hydrophilic functional groups can generate strong interactions with the polar glass substrate, thereby significantly improving the interfacial compatibility between the adhesive layer and the PO original film and glass substrate, solving the interfacial peeling problem that is prone to occur in traditional adhesive layers. The composite photoinitiator is a compound system of 1-hydroxycyclohexylphenyl ketone (1173) and benzophenone (BP) in a mass ratio of 3:1. 1173, as a highly efficient hydrogen-abstracting photoinitiator, can rapidly decompose under UV irradiation to generate free radicals to initiate polymerization reactions. BP, as a photosensitizing synergist, can effectively broaden the light absorption range and improve the photoinitiation efficiency. The synergistic effect of the two enables the adhesive layer to achieve rapid and full curing under UV irradiation, and the adhesive layer performance is uniform and stable after curing, further optimizing the peel force control effect before and after UV irradiation.

[0010] Furthermore, the fluorinated polyurethane acrylate prepolymer is prepared by stepwise polymerization of isophorone diisocyanate, poly(1,4-butanediol adipate), fluorinated ethanol, and hydroxyethyl acrylate. The fluorine element introduced into its molecular chain can significantly improve the chemical corrosion resistance and surface smoothness of the adhesive layer. The polyurethane segments endow the adhesive layer with good flexibility and adhesion, while the acrylate double bonds provide reaction sites for UV curing. The introduction of this prepolymer enables the composite adhesive layer to have etching resistance, high adhesion strength, and UV responsiveness, providing comprehensive performance assurance for UTG glass thinning processing.

[0011] Furthermore, the modified PO base film is made by blending polyethylene and polypropylene at a mass ratio of 7:3-5:5. During the blending process, antioxidant 1010 and ultraviolet absorber UV-531 are added at a mass ratio of 0.5-2% and 0.3-1% respectively. Antioxidant 1010 can inhibit the oxidative degradation of the PO base film during processing and use, while ultraviolet absorber UV-531 can reduce the impact of UV irradiation on the performance of the PO base film and extend the service life of the film material. The modified PO base film prepared by melt blending in a twin-screw extruder at 160-180℃ and then by casting molding has a tensile strength ≥120MPa, elongation at break ≥300%, and temperature resistance ≥100℃, which can meet the mechanical properties and thermal stability requirements of UTG glass thinning process.

[0012] Furthermore, 0.1-0.5% of defoamer and 0.2-0.8% of leveling agent by weight are added to the composite adhesive layer. The defoamer is an organosilicon compound, which can effectively eliminate bubbles generated during the preparation of the adhesive layer and avoid bonding defects and appearance flaws caused by bubbles. The leveling agent is an acrylate copolymer, which can improve the coating performance of the adhesive layer, so that the adhesive layer forms a smooth and uniform film on the surface of the PO original film, improve the appearance quality and bonding uniformity of the adhesive layer, and further ensure the yield of UTG glass thinning processing.

[0013] Furthermore, a process for preparing a UV photosensitive anti-adhesion film includes the following steps: S1. Pretreatment of Modified PO Film: First, the surface of the modified PO film is activated using argon-oxygen mixed plasma. The plasma power is controlled at 320-400W, the treatment time is 25-35s, and the volume ratio of argon to oxygen is 1:1. Through the physical bombardment and chemical action of the plasma, oil and impurities on the surface of the PO film can be removed, while introducing active functional groups such as hydroxyl and carboxyl groups to improve the dyne value of the film surface. Subsequently, a polyurethane primer is coated on the activated PO film surface, with the coating amount controlled at 0.6-1.2g / m². The primer can further enhance the interfacial bonding force between the adhesive layer and the PO film. The dyne value of the PO film surface after pretreatment is ≥38mN / m, laying a good foundation for subsequent adhesive layer coating and bonding. S2. Preparation of the composite adhesive layer: According to the components and mass proportions described in any one of claims 1-7, the fluorine-modified polyurethane acrylate prepolymer, multifunctional UV monomer, composite photoinitiator, dual-interface modifier, and other additives are added sequentially to a stirring container and stirred for 60-90 minutes at 25-30℃ and 300-500 r / min to ensure thorough and uniform mixing of all components; then, the mixture is dispersed using an ultrasonic disperser at 800-1000W power for 20-30 minutes to further refine the microparticles in the system and eliminate agglomeration; finally, the uniformly dispersed adhesive layer slurry is degassed for 30-60 minutes under a vacuum degree ≤-0.09MPa to remove air bubbles and obtain a uniform and stable composite adhesive layer slurry; S3. Coating: Using a doctor blade coating process, the composite adhesive slurry is evenly coated onto the surface of the pretreated modified PO film. During the coating process, the doctor blade speed is controlled at 5-10 m / min, and the doctor blade gap is precisely adjusted according to the target adhesive layer thickness to ensure that the wet film thickness is uniformly controlled at 15-45 μm. After coating, the film material is left to stand for 5-10 minutes to allow the slurry to flow and level fully. S4. Pre-curing: The coated film material is placed in an oven and pre-cured at 65-75℃ for 3-4 minutes. The pre-curing process can gradually remove the solvent in the adhesive slurry, avoiding defects such as pinholes and bubbles in the cured adhesive layer caused by solvent residue. At the same time, it can promote the initial reaction of some components and improve the efficiency and effect of subsequent UV curing. S5. UV Curing: The pre-cured film material is sent into a UV curing machine and cured by irradiation with a UV LED lamp with a wavelength of 365nm. The curing energy is controlled at 750-950mJ / cm². During the curing process, the film material transmission speed is controlled at 3-5m / min to ensure that the adhesive layer is fully cured. Through UV curing, the double bonds in the adhesive layer undergo a polymerization reaction to form a cross-linked network, thereby achieving precise control of the adhesive force. S6. Low-temperature post-treatment: Place the UV-cured film in an oven at 80-85℃ for 1.5-2.5 minutes. Low-temperature post-treatment can further promote the complete reaction inside the adhesive layer, eliminate internal stress, and make the adhesive layer performance more stable. At the same time, it can enhance the interfacial bonding strength between the adhesive layer and the original PO film, and finally obtain a high-performance UV photosensitive anti-adhesion film.

[0014] Furthermore, in step S1, the polyurethane primer is a polyether-type polyurethane resin with a solid content controlled at 30-40%. The coating method adopts a micro-gravure coating process, which has high coating precision and can ensure uniform primer thickness. After the primer is applied, it is dried at 80-90℃ for 1-2 minutes to allow the primer to fully dry and cure, further improving the adhesion with the PO original film and subsequent composite adhesive layers, and effectively preventing interface peeling during processing.

[0015] Furthermore, in step S5, the UV curing machine adopts a multi-segment irradiation design, with a total of 3-5 UV LED lamp groups. The power of each lamp group can be adjusted independently. By gradually increasing the irradiation power, the adhesive layer is cured in a gradient manner, avoiding uneven shrinkage or performance fluctuations caused by instantaneous high-intensity irradiation. Nitrogen protection is used during the curing process, and the nitrogen flow rate is controlled at 10-20 m³ / h, which can effectively inhibit the polymerization inhibition effect of oxygen, improve curing efficiency and curing degree, ensure the stability and consistency of adhesive layer performance, and provide process assurance for precise control of peel force before and after UV irradiation.

[0016] (iii) Beneficial technical effects Compared with existing technologies, the beneficial effects of this invention are: This invention significantly improves the chemical resistance and interfacial compatibility of the anti-adhesion film through innovative adhesive layer formulation design. The unique composite adhesive layer system balances the inert surface of the original PO film with the polar surface of the glass substrate, effectively improving the bonding effect between the adhesive layer and both types of substrates. This ensures high adhesion strength before UV irradiation, preventing displacement of the UTG glass during etching and grinding, while also achieving rapid anti-adhesion after UV irradiation, resulting in damage-free peeling and completely avoiding the problems of edge chipping and surface scratches in ultra-thin glass. Simultaneously, the introduction of specific components in the adhesive layer endows it with excellent etching resistance, allowing it to work stably in hydrofluoric acid / nitric acid etching systems without swelling, degradation, or interfacial peeling, ensuring the continued effectiveness of its fixing function.

[0017] Secondly, the selection of modified PO base film and the optimization of pretreatment processes significantly improve the thermal stability of the anti-tack film. The modified PO base film itself possesses excellent thermal stability and exhibits extremely low shrinkage during the drying process, effectively preventing UTG glass warping caused by film shrinkage and ensuring the dimensional accuracy and flatness of the product. Furthermore, the composite pretreatment process further enhances the activity and adhesion of the PO base film surface, laying the foundation for a strong bond between the adhesive layer and the substrate, enabling the anti-tack film to maintain structural stability even in complex processing environments.

[0018] Furthermore, this invention achieves effective control of residual adhesive rate through precise formula adjustment and process parameter optimization. The synergistic effect of the adhesive layer components ensures no adhesive residue remains on the glass surface after peeling, guaranteeing high light transmittance and surface smoothness of the UTG glass. No additional cleaning process is required, improving processing efficiency. Simultaneously, the synergistic design of the composite adhesive layer and the modified PO original film gives the anti-adhesion film both excellent mechanical properties and operational stability, making it suitable for various processes in UTG processing and applicable to a wide range of applications.

[0019] Finally, the technical solution of this invention balances performance and cost advantages. Leveraging the low-cost characteristics of PO primary film, it achieves high performance without significantly increasing production costs, making it easy to scale up and apply. It not only greatly improves the yield of UTG thinning processes and reduces production costs, but also provides stable and reliable performance assurance for end products, promoting the continued development of flexible electronics industries such as foldable screens and wearable devices, and possesses significant economic value and market prospects. Attached Figure Description

[0020] Figure 1 This invention discloses a process flow diagram for preparing a UV anti-adhesion film for dual-crosslinked controlled UTG processing; Figure 2 This is a line graph showing the effect of different UV curing energies on peel strength; Figure 3 This is a bar chart showing the effect of different PO original film blend ratios on the heat shrinkage rate; Figure 4This is a bar chart showing the effect of different amounts of dual-interface modifiers on interfacial bonding strength. Figure 5 This is a line graph showing the effect of different pre-curing temperatures on the residual solvent content of the adhesive layer. Figure 6 This is a radar chart comparing the core performance of the embodiment and the comparative example. Detailed Implementation

[0021] according to Figures 1 to 6 The specific embodiments of the present invention are as follows: The technical solution of the UV photo-induced anti-adhesion film for thinning PO-based UTG glass according to the present invention is described in detail below with reference to three embodiments and one comparative example. All operations were carried out in a cleanroom with a cleanliness level of 100,000, and all raw materials used were industrial-grade high-purity products. Each process parameter was strictly controlled within the range defined in the claims. The effectiveness and superiority of the technical solution of the present invention were verified through differentiated design.

[0022] Example 1 Raw material preparation A modified PO base film, a blend of polyethylene and polypropylene at a mass ratio of 6:4, was selected. This base film had a thickness of 150 μm, a tensile strength of 130 MPa, a temperature resistance of 105℃, and an initial heat shrinkage rate of 0.5%. The adhesive layer materials were prepared according to the following mass percentages: 42% fluorinated modified polyurethane acrylate prepolymer, 20.5% trimethylolpropane triacrylate, 24.5% 1,6-hexanediol diacrylate, 3% 1-hydroxycyclohexylphenyl ketone, 1% benzophenone, 1.5% KH-560, and 1.5% fluorinated modified coupling agent. The mass ratio of trimethylolpropane triacrylate to 1,6-hexanediol diacrylate was 1:1.2, and the mass ratio of 1-hydroxycyclohexylphenyl ketone to benzophenone was 3:1. KH-560 and the fluorinated modified coupling agent together constituted a dual-interface modifier, with a total proportion of 3%. The polyurethane primer was a polyether-type polyurethane resin with a solid content of 35%. The etching solution is a mixture of hydrofluoric acid and nitric acid in a volume ratio of 3:1.

[0023] Preparation steps S1. Pretreatment of Modified PO Film: The modified PO film was fixed on the conveyor belt of the plasma treatment equipment. The volume ratio of argon to oxygen was set to 1:1, the plasma power was 360W, and the treatment time was 30s. The plasma bombardment removed oil stains from the film surface and introduced active functional groups. Subsequently, a polyurethane primer was coated using a microgravure coating process, with the coating amount controlled at 0.9g / m². After coating, the film was immediately placed in an oven at 80℃ for 1min to dry. After treatment, the dyne value of the original film surface was measured to be 40mN / m.

[0024] S2. Preparation of the composite adhesive layer: According to the above mass ratio, fluorine-modified polyurethane acrylate prepolymer, trimethylolpropane triacrylate, and 1,6-hexanediol diacrylate are added sequentially to a high-speed stirred tank. The mixture is stirred for 40 minutes at 28℃ and a stirring rate of 400 r / min. After homogeneity, 1-hydroxycyclohexylphenyl ketone and benzophenone are added, and stirring continues for 20 minutes. Then, KH-560 and a fluorine-modified coupling agent are added, and the mixture is stirred for 30 minutes. The mixed slurry is transferred to an ultrasonic disperser and dispersed for 25 minutes at a power of 900W to eliminate micro-agglomerates. Finally, degassing is performed for 45 minutes under a vacuum of -0.095 MPa to obtain a uniform, bubble-free composite adhesive layer slurry.

[0025] S3. Coating: Using a scraper-type coating equipment, the composite adhesive slurry is coated onto the surface of the pretreated PO membrane. By adjusting the scraper gap and conveying speed, the wet membrane thickness is controlled to be 10μm. After coating, the membrane is left to stand for 8 minutes to allow the slurry to flow and level fully.

[0026] S4. Pre-curing: The coated film is sent into a tunnel oven. The oven temperature is set to 70℃, the conveying speed is 1.2m / min, and the corresponding pre-curing time is 3.5min. Pre-curing removes residual solvent from the slurry.

[0027] S5, UV Curing: The pre-cured film material enters the UV curing machine, using a UV LED lamp with a wavelength of 365nm, setting the curing energy to 850mJ / cm², and the conveying speed to 3.5m / min to ensure that the adhesive layer is fully cross-linked and cured.

[0028] S6. Low-temperature post-treatment: The UV-cured film material is placed in an oven at 82℃ and kept at that temperature for 2 minutes to eliminate internal stress and enhance the interfacial bonding between the adhesive layer and the original PO film. After natural cooling, it is rolled up to obtain the finished UV photosensitive anti-adhesion film.

[0029] Example 2 Raw material preparation A modified PO base film, a blend of polyethylene and polypropylene at a mass ratio of 7:3, was selected. This base film had a thickness of 80 μm, a tensile strength of 125 MPa, a temperature resistance of 100℃, and an initial heat shrinkage rate of 0.14%. The adhesive layer materials were prepared according to the following mass proportions: 40% fluorinated modified polyurethane acrylate prepolymer, 20.9% trimethylolpropane triacrylate, 25.1% 1,6-hexanediol diacrylate, 2.6% 1-hydroxycyclohexylphenyl ketone, 0.9% benzophenone, and 3.5% dual-interface modifier. The mass ratio of trimethylolpropane triacrylate to 1,6-hexanediol diacrylate was 1:1.2, and the mass ratio of 1-hydroxycyclohexylphenyl ketone to benzophenone was 3:1. The polyurethane primer was a polyether-type polyurethane resin with a solid content of 32%. The etching solution was a mixture of hydrofluoric acid and nitric acid at a volume ratio of 3:1.

[0030] Preparation steps S1. Pretreatment of Modified PO Film: The modified PO film was fixed on the conveyor belt of the plasma treatment equipment. The volume ratio of argon to oxygen was set to 1:1, the plasma power was 340W, and the treatment time was 28s. Plasma bombardment was used to remove oil stains from the film surface and introduce active functional groups. Subsequently, a polyurethane primer was coated using a microgravure coating process, with the coating amount controlled at 0.7g / m². After coating, the film was immediately placed in an oven at 80℃ for 1min to dry. After treatment, the dyne value of the original film surface was measured to be 39mN / m.

[0031] S2. Preparation of the composite adhesive layer: According to the above mass ratio, fluorine-modified polyurethane acrylate prepolymer, trimethylolpropane triacrylate, and 1,6-hexanediol diacrylate are added sequentially to a high-speed stirred tank. The mixture is stirred for 40 minutes at 25°C and a stirring rate of 350 r / min. After homogeneity, 1-hydroxycyclohexylphenyl ketone and benzophenone are added, and stirring continues for 30 minutes. Then, a dual-interface regulator is added, and stirring is continued for 20 minutes. The mixed slurry is transferred to an ultrasonic disperser and dispersed for 28 minutes at a power of 850 W to eliminate micro-agglomerates. Finally, degassing is performed for 50 minutes under a vacuum of -0.095 MPa to obtain a uniform, bubble-free composite adhesive layer slurry.

[0032] S3. Coating: Using a scraper-type coating equipment, the composite adhesive slurry is coated onto the surface of the pretreated PO film. By adjusting the scraper gap and conveying speed, the wet film thickness is controlled to be 20μm. After coating, the film is left to stand for 10 minutes to allow the slurry to flow and level fully.

[0033] S4. Pre-curing: The coated film material is sent into a tunnel oven. The oven temperature is set to 68℃, the conveying speed is 1.0m / min, and the corresponding pre-curing time is 3.8min. Pre-curing removes residual solvents from the slurry.

[0034] S5. UV Curing: The pre-cured film material enters the UV curing machine, using a UV LED lamp with a wavelength of 365nm, setting the curing energy to 800mJ / cm², and the conveying speed to 3.2m / min to ensure that the adhesive layer is fully cross-linked and cured.

[0035] S6. Low-temperature post-treatment: The UV-cured film material is placed in an oven at 83℃ and kept at that temperature for 1.8 minutes to eliminate internal stress and enhance the interfacial bonding between the adhesive layer and the original PO film. After natural cooling, it is rolled up to obtain the finished UV photosensitive anti-adhesion film.

[0036] Example 3 Raw material preparation A modified PO base film, a blend of polyethylene and polypropylene at a mass ratio of 5:5, was selected. This base film had a thickness of 120 μm, a tensile strength of 128 MPa, a temperature resistance of 102℃, and an initial heat shrinkage rate of 0.3%. The adhesive layer materials were prepared according to the following mass percentages: 45% fluorinated modified polyurethane acrylate prepolymer, 19.1% trimethylolpropane triacrylate, 22.9% 1,6-hexanediol diacrylate, 3.8% 1-hydroxycyclohexylphenyl ketone, 1.2% benzophenone, 1% KH-560, and 1% fluorinated modified coupling agent. The mass ratio of trimethylolpropane triacrylate to 1,6-hexanediol diacrylate was 1:1.2, and the mass ratio of 1-hydroxycyclohexylphenyl ketone to benzophenone was 3:1. KH-560 and the fluorinated modified coupling agent together constituted a dual-interface modifier, with a total proportion of 2%. The polyurethane primer was a polyether-type polyurethane resin with a solid content of 38%. The etching solution is a mixture of hydrofluoric acid and nitric acid in a volume ratio of 3:1.

[0037] Preparation steps S1. Pretreatment of Modified PO Film: The modified PO film was fixed on the conveyor belt of the plasma treatment equipment. The volume ratio of argon to oxygen was set to 1:1, the plasma power was 380W, and the treatment time was 32s. The plasma bombardment removed oil stains from the film surface and introduced active functional groups. Subsequently, a polyurethane primer was coated using a microgravure coating process, with the coating amount controlled at 1.1g / m². After coating, the film was immediately placed in an oven at 80℃ for 1min to dry. After treatment, the dyne value of the original film surface was measured to be 38mN / m.

[0038] S2. Preparation of the composite adhesive layer: According to the above mass ratio, fluorine-modified polyurethane acrylate prepolymer, trimethylolpropane triacrylate, and 1,6-hexanediol diacrylate are added sequentially to a high-speed stirred tank. The mixture is stirred for 40 minutes at 30℃ and a stirring rate of 450 r / min. After homogeneity, 1-hydroxycyclohexylphenyl ketone and benzophenone are added, and stirring continues for 20 minutes. Then, KH-560 and a fluorine-modified coupling agent are added, and the mixture is stirred for 30 minutes. The mixed slurry is transferred to an ultrasonic disperser and dispersed for 22 minutes at a power of 1000W to eliminate micro-agglomerates. Finally, degassing is performed for 40 minutes under a vacuum of -0.095 MPa to obtain a uniform, bubble-free composite adhesive layer slurry.

[0039] S3. Coating: Using a doctor blade coating equipment, the composite adhesive slurry is coated onto the surface of the pretreated PO membrane. By adjusting the doctor blade gap and conveying speed, the wet membrane thickness is controlled to be 30μm. After coating, the membrane is left to stand for 3 minutes to allow the slurry to flow and level fully.

[0040] S4. Pre-curing: The coated film material is sent into a tunnel oven. The oven temperature is set to 72℃, the conveying speed is 1.3m / min, and the corresponding pre-curing time is 3.2min. Pre-curing removes residual solvents from the slurry.

[0041] S5, UV Curing: The pre-cured film material enters the UV curing machine, using a UV LED lamp with a wavelength of 365nm, setting the curing energy to 900mJ / cm², and the conveying speed to 3.8m / min to ensure that the adhesive layer is fully cross-linked and cured.

[0042] S6. Low-temperature post-treatment: The UV-cured film is placed in an oven at 85℃ and kept at that temperature for 2.2 minutes to eliminate internal stress and enhance the interfacial bonding between the adhesive layer and the original PO film. After natural cooling, it is rolled up to obtain the finished UV photosensitive anti-adhesion film.

[0043] Comparative Example Raw material preparation Unmodified pure polypropylene (PO) prepolymer film was selected. This film had a thickness of 150 μm, a tensile strength of 110 MPa, a temperature resistance of 95°C, and an initial heat shrinkage rate of 2.5%. The adhesive layer materials were prepared according to the following mass ratios: 45% ordinary polyurethane acrylate prepolymer, 40% trimethylolpropane triacrylate, 10% 1,6-hexanediol diacrylate, and 5% 1-hydroxycyclohexylphenyl ketone. No dual-interface modifier was added. There was no fixed mixing ratio between trimethylolpropane triacrylate and 1,6-hexanediol diacrylate. Only 1-hydroxycyclohexylphenyl ketone was used as the photoinitiator, with no other compounding components. The polyurethane primer and etching solution were selected as in Example 1.

[0044] Preparation steps S1, PO film pretreatment: The PO film was not subjected to plasma activation and polyurethane primer pretreatment and was directly used in the subsequent adhesive coating process.

[0045] S2. Preparation of composite adhesive layer: According to the above mass ratio, ordinary polyurethane acrylate prepolymer, trimethylolpropane triacrylate, 1,6-hexanediol diacrylate and 1-hydroxycyclohexylphenyl ketone are added to the stirring container in sequence. After stirring for 30 minutes, ultrasonic dispersion and vacuum degassing treatment are not performed. The mixture is directly used for coating.

[0046] S3. Coating: A scraper-type coating device is used to coat the composite adhesive slurry onto the surface of the PO original film, and the wet film thickness is controlled to be 10μm. No static treatment is performed after coating.

[0047] S4. Pre-curing: Place the coated film material into an oven, set the oven temperature to 80℃, and the pre-curing time to 2 minutes.

[0048] S5, UV Curing: The pre-cured film material enters the UV curing machine, and the curing energy is set to 700mJ / cm² to complete the curing.

[0049] S6. Low-temperature post-treatment: No low-temperature post-treatment step is required; the product is obtained directly after curing and winding.

[0050] Performance testing and comparison Table 1: Details of Raw Materials and Process Parameters for Examples and Comparative Examples Table 1 Summary: All examples used modified PO films blended with polyethylene and polypropylene, combined with compound photoinitiators and dual-interface modifiers. The tack coat was subjected to ultrasonic dispersion and vacuum degassing via a composite pretreatment process involving plasma activation and a polyurethane primer. The process parameters for pre-curing, UV curing, and low-temperature post-treatment were strictly controlled, comprehensively covering the core technical features of the claims. The comparative examples used unmodified pure polypropylene PO films without dual-interface modifiers, lacking plasma activation and polyurethane primer pretreatment steps. The tack coat was only simply stirred without ultrasonic dispersion and vacuum degassing. The pre-curing and UV curing process parameters were crude, and there was no low-temperature post-treatment step. These examples were used to compare and verify the advantages of the present invention's technical solution.

[0051] Table 2: Core Performance Test Results of Examples and Comparative Examples Table 2 summarizes: The embodiment significantly outperforms the comparative example in all core performance aspects. The embodiment exhibits sufficient pre-UV peel force to stably fix the UTG glass, and a significantly reduced post-UV peel force, enabling damage-free peeling. It demonstrates excellent etching resistance, showing no swelling or peeling after immersion in a mixed etching solution of hydrofluoric acid and nitric acid for 2 hours. The PO original film has extremely low thermal shrinkage, keeping the warpage of the UTG glass at a low level. It also exhibits extremely low residual adhesive content, high glass transmittance, and no cracking or scratches after peeling. In contrast, the comparative example, due to defects in raw material selection and process design, suffers from insufficient pre-UV peel force, excessively high post-UV peel force, poor etching resistance, high thermal shrinkage and residual adhesive content, resulting in low glass transmittance and edge cracking and surface scratches after peeling. This fully verifies the effectiveness of the technical solution of this invention.

[0052] Table 3: Comparison of Processing Yield between Examples and Comparative Examples Table 3 summarizes: The yield rate of UTG glass thinning in the embodiments is above 97%, and the batch production yield rate is consistently above 97%, significantly higher than the approximately 60% of the comparative example. This is because the anti-adhesion film in the embodiments effectively solves problems such as fixation failure, glass warping, residual adhesive, and peeling damage, ensuring the stability and consistency of the processing. The comparative example, due to performance defects, frequently encountered problems such as substrate displacement, etching failure, and glass damage during processing, resulting in a significant drop in yield, further demonstrating the industrialization value of the technical solution of this invention.

[0053] Results Analysis The test data above shows that the UV photosensitive anti-adhesion films prepared in Examples 1-3 of this invention, through the selection of a modified PO film blended with polyethylene and polypropylene, the design of a scientifically sound composite adhesive layer formulation, and the adoption of a complete pretreatment process and a precisely controlled preparation flow, comprehensively solve the pain points of existing technologies. The UV pre-peel force of these examples meets the fixing requirements of UTG glass processing, and the UV post-peel force enables damage-free peeling. They exhibit excellent etching resistance and thermal stability, with extremely low residual adhesive, significantly improving the yield and product quality of UTG glass thinning processing. In contrast, the comparative examples, lacking the core technical features of this invention and using coarse process parameters, fail to meet the usage requirements for various performance aspects, resulting in extremely low processing yield. This fully demonstrates that the technical solution of this invention is scientifically sound and reasonable. Through the synergistic effect of multiple technical features, it achieves comprehensive optimization of the performance of the PO-based UV anti-adhesion film, possessing significant technical advantages and broad prospects for industrial application.

[0054] Reference Figure 2The line graph visually illustrates the relationship between UV curing energy and the peel strength of the anti-adhesive film. As the UV curing energy increases from 700 mJ / cm² to 900 mJ / cm², the peel strength before UV irradiation shows a slow decreasing trend, but remains above 20 N / 25 mm, meeting the fixation requirements during UTG glass processing. After UV irradiation, the peel strength decreases significantly, from 0.5 N / 25 mm to 0.1 N / 25 mm, reaching an optimal balance in the 800-850 mJ / cm² range—ensuring sufficient adhesive strength before curing while achieving damage-free peeling after curing. This pattern verifies the scientific validity of selecting the 750-950 mJ / cm² curing energy range in this invention. Too low an energy level results in insufficient cross-linking, leading to excessively high peel strength and potential damage to the glass; while too high an energy level results in lower peel strength, it can cause embrittlement of the adhesive layer, affecting early-stage bonding stability. This energy range effectively balances both adhesion and peeling requirements.

[0055] Reference Figure 3 The bar chart clearly shows the effect of different blending ratios of polyethylene (PE) and polypropylene (PP) on the heat shrinkage rate of the PO film. The lowest heat shrinkage rate (0.10%) was observed at a blending ratio of 6:4. The heat shrinkage rates remained low at 7:3 and 5:5 ratios, while significantly increased at 9:1 and 3:7 ratios. This is because PE and PP have complementary molecular structures and thermal properties; a 6:4 ratio forms a stable blend system, reducing the tendency of molecular chains to shrink at high temperatures. This invention selects a blending ratio range of 7:3 to 5:5, based on this data. A low shrinkage rate effectively prevents warping of UTG glass during the drying process due to film shrinkage, ensuring the dimensional accuracy of the glass. Blending ratios deviating from this range result in increased heat shrinkage, directly leading to a decrease in glass processing yield, thus verifying the rationality of the film material selection in this invention.

[0056] Reference Figure 4 The chart reflects the relationship between the amount of dual-interface modifier added and the interfacial adhesion. As the addition amount increases from 1% to 3%, the interfacial adhesion continuously rises, reaching a peak of 25 N / 25 mm at 3%. However, when the addition amount exceeds 3%, the adhesion decreases. This is because an appropriate amount of interfacial modifier can simultaneously improve the compatibility between the inert surface of the PO film and the polar surface of the glass, enhancing the adhesion between the adhesive layer and the substrate. However, excessive addition leads to the accumulation of the modifier at the interface, which in turn damages the cross-linking structure of the adhesive layer and reduces the adhesion. This invention sets an addition range of 2-4%, ensuring sufficient interfacial adhesion to avoid interface peeling during etching, while also preventing negative effects from excessive addition. This data provides a direct basis for designing the amount of interfacial modifier in the formulation, ensuring the interfacial stability of the anti-adhesion film under complex process environments.

[0057] Reference Figure 5The line graph clearly shows the relationship between pre-curing temperature and residual solvent content in the adhesive layer. When the temperature rises from 60℃ to 70℃, the residual solvent content drops significantly from 1.2% to 0.4%. Further temperature increases after 70℃ result in a significantly slower rate of decrease in the residual solvent content, maintaining around 0.3% at both 75℃ and 80℃. This indicates that 70℃ is the critical point for solvent evaporation; at this point, most of the residual solvent has been removed, and further temperature increases have limited effect on reducing the residual solvent content. In fact, it may even lead to premature curing of the adhesive layer in certain areas, affecting the subsequent UV curing effect. This invention selects a pre-curing temperature range of 65-75℃, which effectively removes the solvent, preventing defects such as pinholes and bubbles in the cured adhesive layer, while also preventing premature curing caused by excessively high temperatures, ensuring the uniformity and stability of the adhesive layer performance. This data verifies the rationality of the pre-curing process parameter design.

[0058] Reference Figure 6 This radar chart comprehensively compares the overall performance of the embodiments of the present invention with that of the comparative examples. Embodiments 1 and 2 scored above 8.5 points in all performance indicators, particularly excelling in etch resistance, low adhesive residue, and post-UV peeling performance, demonstrating the advantages of the present invention's technical solution. In contrast, the comparative examples scored below 4 points in all indicators, with only 1 point for low adhesive residue and 2 points for post-UV peeling performance, reflecting significant deficiencies in traditional technologies. The high scores of the embodiments stem from the optimization of the composite adhesive layer formulation, the improvement of the original film pretreatment process, and the precise control of curing parameters, resulting in a synergistic improvement in multi-dimensional performance and ensuring that the anti-adhesion film meets the full-process requirements of UTG glass thinning. The comparative examples, lacking a dual cross-linking control design and without original film modification and precise process control, failed to meet the usage requirements in all aspects. This chart visually demonstrates the advanced nature and practicality of the present invention's technical solution.

[0059] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A UV photopolymer anti-adhesion film for thinning PO-based UTG glass, characterized in that, It consists of a modified PO base film and a composite adhesive layer. The modified PO base film is a polyethylene-polypropylene blend modified polyolefin film, and the composite adhesive layer contains a fluorinated modified polyurethane acrylate prepolymer, a multifunctional UV monomer, a composite photoinitiator, and a dual-interface modifier.

2. The UV photo-induced anti-adhesion film according to claim 1, characterized in that, The components of the composite adhesive layer are compounded according to the following mass ratios: 38-45% fluorine-modified polyurethane acrylate prepolymer, 42-48% multifunctional UV monomer, 3-5% composite photoinitiator, and 2-4% dual-interface modifier; The multifunctional UV monomer is a synergistic system of trimethylolpropane triacrylate (TMPTA) and 1,6-hexanediol diacrylate (HDDA) in a mass ratio of 1:1.

2.

3. The UV photo-induced anti-adhesion film according to claim 1, characterized in that, The thickness of the modified PO original film is 60-150μm, and the thickness of the composite adhesive layer is 10-40μm; the peel strength before UV irradiation is 12-26N / 25mm; the peel strength after UV irradiation decreases to 0.05-0.3N / 25mm; the volume ratio of hydrofluoric acid to nitric acid etching solution is 3:1; and the residual adhesive rate is <0.04%.

4. The UV photo-induced anti-adhesion film according to claim 1, characterized in that, The dual-interface modifier is a polyurethane compound system; the composite photoinitiator is a compound system of 1-hydroxycyclohexylphenyl ketone and benzophenone in a mass ratio of 3:

1.

5. The UV photo-induced anti-adhesion film according to claim 1, characterized in that, Fluorine-modified polyurethane acrylate prepolymer is prepared by stepwise polymerization of isophorone diisocyanate, poly(1,4-butanediol adipate), fluoroethanol and hydroxyethyl acrylate.

6. The UV photo-induced anti-adhesion film according to claim 1, characterized in that, The modified PO film is made by blending polyethylene and polypropylene in a mass ratio of 7:3-5:

5. During the blending process, antioxidant 1010 and ultraviolet absorber UV-531, accounting for 0.5-2% of the total mass, are added.

7. The UV photo-induced anti-adhesion film according to claim 1, characterized in that, The composite adhesive layer also contains 0.1-0.5% defoamer and 0.2-0.8% leveling agent by weight. The defoamer is an organosilicon compound, and the leveling agent is an acrylate copolymer.

8. A process for preparing a UV photosensitive anti-adhesion film, used to prepare the UV photosensitive anti-adhesion film according to any one of claims 1-7, characterized in that, Includes the following steps: S1. Pretreatment of modified PO film: First, the surface of the modified PO film is activated by argon-oxygen mixed plasma. The plasma power is controlled at 320-400W, the treatment time is 25-35s, and the volume ratio of argon to oxygen is 1:

1. Then, a polyurethane primer is coated on the activated PO film surface, and the coating amount is controlled at 0.6-1.2g / m². S2. Preparation of composite adhesive layer: Fluorine-modified polyurethane acrylate prepolymer, multifunctional UV monomer, composite photoinitiator, dual-interface modifier and other additives are added sequentially to a stirring container and stirred for 60-90 minutes at 25-30℃ and 300-500 r / min to ensure that all components are fully mixed and uniform. Then, the mixture is dispersed using an ultrasonic disperser at 800-1000W power for 20-30 minutes. Finally, the uniformly dispersed adhesive layer slurry is degassed for 30-60 minutes under a vacuum degree ≤-0.09MPa to remove air bubbles and obtain the composite adhesive layer slurry. S3. Coating: Using a scraper coating process, the composite adhesive slurry is evenly coated onto the surface of the pretreated modified PO film. During the coating process, the scraper speed is controlled at 5-10 m / min. After the coating is completed, the film is left to stand for 5-10 minutes to allow the slurry to flow and level fully. S4. Pre-curing: Place the coated film material into an oven and pre-cur it at 65-75℃ for 3-4 minutes. S5. UV Curing: The pre-cured film material is sent into a UV curing machine and cured by UV LED lamps. The curing energy is controlled at 750-950mJ / cm², and the film material transmission speed is controlled at 3-5m / min during the curing process. S6. Low-temperature post-treatment: Place the UV-cured film in an oven at 80-85℃ and keep it warm for 1.5-2.5 minutes.

9. The preparation process according to claim 8, characterized in that, In step S1, the polyurethane primer is a polyether-type polyurethane resin with a solid content controlled at 30-40%. The coating method is a microgravure coating process. After the primer is applied, it is dried at 80-90℃ for 1-2 minutes.

10. The preparation process according to claim 8, characterized in that, In step S5, the UV curing machine adopts a multi-segment irradiation design, with a total of 3-5 UV LED lamp groups; nitrogen protection is used during the curing process.

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