Strong-acid-corrosion-resistant high-viscosity UV visbreaking protective film and preparation method thereof

Abstract

The invention relates to the technical field of acrylate adhesives, in particular to a strong acid corrosion resistant high-viscosity UV visbreaking protective film and a preparation method thereof. The protective film provided by the invention is prepared from the following raw materials in parts by mass: 50 to 75 parts of high-Tg acrylic UV resin, 25 to 50 parts of low-Tg acrylic UV resin, 1 to 3 parts of photoinitiator, 10 to 20 parts of trifunctional UV active monomer PETA, 50 to 100 parts of solvent and 1 to 3 parts of cross-linking agent. The acid-resistant time of the prepared protective film in a 20wt% HF solution at the temperature of 50 DEG C exceeds 4 h, the adhesive force before UV reaches 1600-1900g / 25mm, the adhesive force after UV is reduced to 0-15g / 25mm, no adhesive residue exists, reliable protection and lossless stripping in a precise element strong acid process can be achieved, the requirements of high-end manufacturing industries such as semiconductors and OLEDs can be met, and meanwhile the protective film has the advantages of being stable in process, environmentally friendly and compliant.

Description

Technical Field

[0001] This invention relates to the field of acrylic adhesives, specifically to a high-viscosity UV-resistant protective film resistant to strong acid corrosion and its preparation method. Background Technology

[0002] In current high-end manufacturing, especially in semiconductor wafer manufacturing, microelectronic packaging, precision metal etching, and the processing of new display panels such as OLED (Organic Light Emitting Diode) and Micro-LED (Micro Light Emitting Diode), precision components often need to undergo harsh chemical corrosion environments, such as hydrofluoric acid, phosphoric acid, mixed acid etching, and electroplating solutions, to achieve micro-patterning and surface treatment. These processes require absolutely reliable temporary protection for untreated areas to prevent acid corrosion, which could cause irreversible product damage and huge losses. Therefore, the protective film must be able to adhere continuously and stably to the substrate surface for tens of hours of acid etching, effectively resisting acid penetration, erosion, and the resulting swelling, hydrolysis, or peeling of the adhesive layer, i.e., possessing excellent acid resistance stability. This requires the protective film adhesive system to have an initial tack greater than 10N / 25mm and high cohesive strength, and to form a dense, seamless bond with materials of various surface energies.

[0003] However, traditional high-adhesion protective films or conventional acid-resistant protective films need to be peeled off after the process. Because they need to resist strong acid attacks, their adhesive layers are usually designed to be highly cross-linked or made with chemically inert polymers, resulting in consistently extremely high peel strength. During removal, the enormous peel stress can easily cause the ultra-thin, brittle substrate to crack, develop microcracks, or suffer internal damage. Simultaneously, high-cohesive adhesive layers are more prone to cohesive failure rather than interfacial separation during peeling, resulting in difficult-to-remove residues or a visible "white haze" phenomenon, contaminating delicate surfaces and significantly reducing product yield—unacceptable for high-value semiconductor devices and display panels.

[0004] To address the technical challenge of residual adhesive, ultraviolet (UV) anti-adhesion technology has been introduced into the field of protective films. These films incorporate photosensitive compounds in the adhesive layer, which undergo a photochemical reaction upon exposure to UV light of a specific wavelength, significantly reducing adhesion and achieving low-stress, clean removal. However, existing UV anti-adhesion film technologies, in pursuit of rapid photosensitivity and high anti-adhesion efficiency, have inherent deficiencies in their adhesive layer formulations regarding chemical resistance, particularly strong acid corrosion. They rapidly fail in concentrated acid environments, completely failing to meet the long-term protection requirements of the aforementioned acid etching processes, thus limiting their application. Although there have been attempts in the industry to integrate acid resistance and anti-adhesion functions, such as using multilayer composite structures or adding acid-resistant fillers, these solutions often present new inherent problems: multilayer film interfaces are prone to delamination under acidic and thermal environments; physically blended fillers may disrupt the uniformity of the adhesive layer and affect UV light transmittance and reaction efficiency; and most solutions still require heat treatment to achieve sufficiently low peel force, which not only increases energy consumption and processing time but also poses a threat to heat-sensitive components. Therefore, existing technologies have always struggled to achieve synergy and balance in the three key performance indicators of "long-term acid resistance stability", "high initial adhesion" and "efficient and gentle light-triggered de-adhesion". The market urgently needs an innovative protective film solution. Developing such products is of vital importance to promoting technological progress in high-end manufacturing and improving production yield and efficiency. Summary of the Invention

[0005] To solve the above-mentioned technical problems, the first aspect of the present invention provides a high-viscosity UV anti-adhesion protective film resistant to strong acid corrosion, the raw materials for which are prepared by mass parts include: 50-75 parts of high Tg (glass transition temperature) acrylic UV resin, 25-50 parts of low Tg acrylic UV resin, 1-3 parts of photoinitiator, 10-20 parts of UV active monomer, 50-100 parts of solvent, and 1-3 parts of crosslinking agent.

[0006] As an feasible example, the high Tg acrylic UV resin has a weight-average molecular weight of 150,000-250,000 and a Tg of 20-30℃. As an feasible example, the weight-average molecular weight of low-Tg acrylic UV resin is 150,000-250,000, and Tg = -10~0℃.

[0007] As an feasible example, the raw materials for preparing the high Tg acrylic UV resin include, by mass parts: 5-10 parts EHA (isooctyl acrylate), 10-20 parts BA (butyl acrylate), 10-20 parts MMA (methyl methacrylate), 3-8 parts AA (acrylic acid), 0.5-1 part free radical initiator, 30-70 parts solvent, 10-20 parts GMA (glycidyl methacrylate), 1-3 parts antioxidant, 1-3 parts phase transfer catalyst, and 1-3 parts polymerization inhibitor.

[0008] Furthermore, the phase transfer catalyst comprises one of tetra-n-butylammonium bromide, tetra-n-butylammonium chloride, trioctylmethylammonium chloride, or tetraphenylphosphine bromide.

[0009] Furthermore, the preparation method of the high Tg acrylic UV resin includes: EHA, BA, MMA, AA, free radical initiator and solvent are mixed and reacted at 83-87℃ for 6-10h; then GMA, antioxidant, phase transfer catalyst and polymerization inhibitor are added and reacted at 75-79℃ for 3-5h to obtain high Tg acrylic UV resin.

[0010] As an feasible example, the raw materials for preparing the low Tg acrylic UV resin include, by mass parts: 5-15 parts EHA, 20-40 parts BA, 5-10 parts MMA, 3-8 parts AA, 0.5-1 part free radical initiator, 30-70 parts solvent, 10-20 parts GMA, 1-3 parts antioxidant, 1-3 parts phase transfer catalyst, and 1-3 parts polymerization inhibitor.

[0011] Furthermore, the preparation method of the low-Tg acrylic UV resin includes: EHA, BA, MMA, AA, free radical initiator and solvent are mixed and reacted at 83-87℃ for 6-10h; then GMA, antioxidant, phase transfer catalyst and polymerization inhibitor are added and reacted at 75-79℃ for 3-5h to obtain low Tg acrylic UV resin.

[0012] Furthermore, in the raw materials for preparing the high Tg acrylic UV resin, the mass ratio of EHA, BA and MMA is 8:15:15.

[0013] Furthermore, in the raw materials for preparing the low-Tg acrylic UV resin, the mass ratio of EHA, BA, and MMA is 10:30:8. This invention uses two self-made low-Tg acrylic UV resins and high-Tg acrylic UV resins with molecular weights of 150,000-250,000 as the main adhesive system. This compound is not a simple superposition of properties, but rather solves the defects of a single resin and meets the core requirements of the protective film through multi-faceted synergistic effects. On the one hand, the combination of the two can balance "high initial adhesion" and "good adhesion". The low Tg acrylic UV resin fills the microscopic gaps in the substrate with its flexible molecular chains, achieving an initial adhesion of 0-2# small balls to meet the adhesion requirements. The high Tg acrylic UV resin provides strong cohesive strength with its rigid molecular chains, increasing the pre-UV adhesion to 1400-1900g / 25mm, avoiding film detachment or acid seepage during strong acid etching, and solving the problems of poor adhesion of high Tg resin alone and insufficient adhesion of low Tg resin alone. On the other hand, the combination of the two can build a "dense cross-linking foundation". The high Tg acrylic UV resin has a high density of active sites on its molecular chains, which can form more cross-linking nodes with cross-linking agents and UV active monomers. The low Tg acrylic UV resin fills the tiny gaps after cross-linking. The two work together to form a dense cross-linking structure with rigidity and flexibility, making the protective film acid resistant for more than 4 hours in 20wt% HF solution at 50℃, preventing acid penetration, and achieving the technical effects of long-term acid resistance, high initial adhesion, and efficient UV tack reduction.

[0014] As an implementable example, the photoinitiator includes one of TPO (2,4,6-trimethylbenzoyl-diphenylphosphine oxide), 184 initiator (1-hydroxycyclohexylphenyl ketone), 1173 initiator (2-hydroxy-2-methyl-1-phenyl-1-propanone), benzophenone, or 2-isopropylthioxanthraphenone.

[0015] Furthermore, the photoinitiator is TPO.

[0016] As an implementable example, the UV-active monomers include one or more of dipentaerythritol hexaacrylate (DPHA), pentaerythritol triacrylate (PETA), 601Q (purchased from Changxing Materials Industry Co., Ltd.), BN4328 monomer, or BN4332 monomer.

[0017] Furthermore, the functionality of the UV-active monomer is 3.

[0018] Furthermore, the UV monomer is PETA with 3 functionalities.

[0019] PETA molecules contain three acrylate double bond functional groups that can participate in photochemical reactions. During the curing stage of the adhesive layer before UV irradiation, it can form a "moderate and dense" three-dimensional cross-linking network with the active sites and cross-linking agents on the main resin (high Tg acrylic UV resin), 25-50 parts of low Tg acrylic UV resin molecular chains, and other components. Compared to low-functionality monomers, the three double bonds provide a higher density of cross-linking points, which can significantly improve the cohesive strength and interfacial adhesion of the adhesive layer, enabling the adhesion before UV irradiation to reach 1400-1800 g / 25mm, meeting the bonding requirements of the protective film not falling off or shifting during strong acid etching. Compared to high-functionality monomers such as the six-functionality DPHA, the cross-linking network formed by the three-functionality monomers will not cause the adhesive layer to become brittle due to excessive cross-linking, while also constructing a sufficiently dense structure to prevent acid penetration.

[0020] As an implementable example, the crosslinking agent includes one of IPDI (isophorone diisocyanate), N75 crosslinking agent, TT480 crosslinking agent, or aluminum acetylacetonate.

[0021] Furthermore, the crosslinking agent is IPDI.

[0022] IPDI, as a pure aliphatic isocyanate, does not contain aromatic groups that are easily destroyed by strong acids. It forms stable urethane bonds with both low-Tg and high-Tg acrylic UV resins. Furthermore, its two distinctly different -NCO groups enable "stepwise controllable crosslinking," constructing a uniform and dense three-dimensional crosslinked network that effectively prevents acid penetration. Testing shows an acid resistance time >4 hours with no acid seepage or corrosion. Simultaneously, IPDI's differentiated -NCO groups rapidly form a preliminary crosslinking framework with the resin carboxyl groups, then slowly refine the network with hydroxyl groups. This enhances the cohesive strength of the adhesive layer, achieving a pre-UV adhesion of 1600-1900 g / 25 mm, meeting the bonding requirements of strong acid processes. The controllable crosslinking also maintains the cohesive strength of the adhesive layer at the "interface separation" threshold after UV tack reduction. During peeling, the adhesive layer only breaks at the interface with the substrate, without cohesive damage, resulting in no residue and stable post-UV adhesion of 0-15 g / 25 mm.

[0023] The second aspect of the present invention provides a method for preparing a high-viscosity UV anti-adhesion protective film resistant to strong acid corrosion, comprising: mixing high-Tg acrylic UV resin, low-Tg acrylic UV resin, photoinitiator, UV active monomer, solvent, and crosslinking agent evenly, then coating and curing, to obtain a high-viscosity UV anti-adhesion protective film resistant to strong acid corrosion.

[0024] Beneficial effects (i) The protective film prepared by this invention can be stably withstood in 50℃ and 20wt% HF solution for more than 4 hours. During this period, there is no discoloration, deformation, cracking or other corrosion on the film surface, and the pH test paper does not show acid seepage or discoloration. It can effectively block strong acid penetration and prevent the protected precision components from being damaged in the etching process, thus meeting the stringent strong acid environmental protection requirements of high-end manufacturing industry.

[0025] (ii) The protective film prepared by the present invention has an adhesion of 1600-1900g / 25mm before UV irradiation, which can adhere tightly to the surface of the substrate and ensure that it does not shift or fall off during strong acid etching. At the same time, the initial adhesion test shows that it is 0-2# small ball, which has good automatic bonding performance and is suitable for automatic bonding process in industrial production, thus improving operation efficiency.

[0026] (iii) After UV irradiation, the adhesive force of the protective film prepared by the present invention can be stably reduced to 0-15g / 25mm, achieving near-zero stress peeling, avoiding cracking and micro-cracks in ultra-thin and brittle substrates due to excessive peeling stress; and there is no adhesive residue after peeling, which will not contaminate the surface of the substrate and ensure product yield.

[0027] (iv) In the protective film adhesive system of the present invention, the IPDI crosslinking agent has good compatibility with the self-produced low Tg acrylic UV resin and high Tg acrylic UV resin, has excellent solubility in solvent, and has no problems of layering or precipitation; in the resin synthesis and subsequent coating process, the reactivity of each component is stable, the adhesive solution has a long pot life, and the process stability of large-scale production can be guaranteed.

[0028] (v) The protective film prepared by the present invention uses acrylic adhesive, which is halogen-free, and the substrate and additives used comply with international environmental protection standards such as RoHS 2.0 and REACH. There is no release of harmful components, which is suitable for the environmental protection production requirements of high-end manufacturing industry and avoids harm to the environment and operators. Detailed Implementation

[0029] In Examples 1-12 of this invention, the weight-average molecular weight of the high-Tg acrylic UV resin is approximately 200,000; the weight-average molecular weight of the low-Tg acrylic UV resin is approximately 200,000; the Tg of the high-Tg acrylic UV resin is 25°C, and the Tg of the low-Tg acrylic UV resin is -10°C.

[0030] The raw materials for preparing the high Tg acrylic UV resin are as follows, by mass: 8 parts EHA, 15 parts BA, 15 parts MMA, 5 parts AA, 0.5 parts AIBN, 30 parts ethyl acetate, 20 parts butyl acetate, 15 parts GMA, 1 part antioxidant 1010, 1 part tetrabutylammonium bromide, and 1 part DBHQ (2,5-di-tert-butylhydroquinone) polymerization inhibitor.

[0031] The preparation method of the high Tg acrylic UV resin is as follows: EHA, BA, MMA, AA, AIBN and ethyl acetate and butyl acetate are mixed and reacted at 85°C for 7 hours; then GMA, antioxidant 1010, tetrabutylammonium bromide and DBHQ polymerization inhibitor are added and reacted at 77°C for 4 hours to obtain the high Tg acrylic UV resin; the high Tg acrylic UV resin is designated as A111 resin.

[0032] The raw materials for preparing the low Tg acrylic UV resin are as follows, by mass: 10 parts EHA, 30 parts BA, 8 parts MMA, 5 parts AA, 0.5 parts AIBN, 30 parts ethyl acetate, 20 parts butyl acetate, 15 parts GMA, 1 part antioxidant 1010, 1 part tetrabutylammonium bromide, and 1 part DBHQ polymerization inhibitor.

[0033] The preparation method of the low Tg acrylic UV resin is as follows: EHA, BA, MMA, AA, AIBN and ethyl acetate and butyl acetate are mixed and reacted at 85°C for 7 hours; then GMA, antioxidant 1010, tetrabutylammonium bromide and DBHQ polymerization inhibitor are added and reacted at 77°C for 4 hours to obtain the low Tg acrylic UV resin; the low Tg acrylic UV resin is designated as A222 resin.

[0034] Experimental Group 1: Selection of Main Resin Mass Ratio Examples 1-4 The raw materials and their mass fractions for the preparation of Examples 1-4 are detailed in Table 1.

[0035] The performance test results of the products in Examples 1-4 are detailed in Table 2.

[0036] The specific preparation method of the high-viscosity UV anti-tack protective film resistant to strong acid corrosion is as follows: mix high-Tg acrylic UV resin, low-Tg acrylic UV resin, photoinitiator, UV active monomer, solvent, and crosslinking agent, react, then coat and cure to obtain the high-viscosity UV anti-tack protective film resistant to strong acid corrosion.

[0037] Table 1

[0038] Table 2

[0039] Example 1: 20 parts of self-made A111 resin and 80 parts of A222 resin were used for testing. A UV film was prepared using the basic formula and its initial tack was tested to characterize the adhesion of the UV anti-tack protective film. The test used 5-9# small balls, indicating excessively high initial tack. The UV anti-tack protective film was then placed in a 50℃, 20wt% HF solution for acid resistance testing. After 1-2 hours, pH test paper on the UV film surface was observed. The test paper changed color, indicating acid seepage. The UV film separated from the protected surface. The UV film surface remained smooth and flat, without any signs of corrosion or blistering, indicating that the UV anti-tack protective film met the acid resistance requirements. However, due to low UV pre-adhesion and insufficient adhesion, the UV film detached from the protected surface, leading to acid seepage. Adjustment of the UV pre-adhesion is necessary.

[0040] Example 2 used 40 parts of self-made A111 resin and 60 parts of A222 resin for testing. After coating a UV film using the basic formula, its initial tack performance was tested to characterize the adhesion of the UV anti-tack protective film. The test used 2-5# small balls, and the initial tack was too high. Then, the UV anti-tack protective film was placed in a 50℃, 20wt% HF solution for acid resistance testing. After 2-3 hours, the pH test paper on the UV film surface was observed. The test paper changed color, indicating acid seepage, and the UV film separated from the protected surface. The UV film surface remained smooth and flat, without any signs of corrosion or blistering, indicating that the UV anti-tack protective film met the acid resistance requirements. However, due to the low UV pre-adhesion and insufficient adhesion, the UV film detached from the protected surface, leading to acid seepage. The UV pre-adhesion needs to be adjusted.

[0041] Example 3 used 60 parts of self-made A111 resin and 40 parts of A222 resin for testing. After coating a UV film using the basic formula, its initial tack performance was tested to characterize the adhesion of the UV anti-tack protective film. The test was conducted on 0-2# small balls, and the initial tack was suitable. Then, the UV anti-tack protective film was placed in a 50℃, 20wt% HF solution for acid resistance testing. After 3-4 hours, the pH test paper on the UV film surface was observed. The test paper changed color, indicating acid seepage, and the UV film separated from the protected surface. The UV film surface remained smooth and flat, without any signs of corrosion or blistering, indicating that the UV anti-tack protective film met the acid resistance requirements. However, due to the low UV pre-adhesion and insufficient adhesion, the UV film detached from the protected surface, leading to acid seepage. The UV pre-adhesion needs to be adjusted.

[0042] Example 4 used 80 parts of self-made A111 resin and 20 parts of A222 resin for testing. After coating a UV film using the basic formula, its initial tack performance was tested to characterize the adhesion of the UV anti-tack protective film. The test used a #0 ball, indicating low initial tack. The UV anti-tack protective film was then placed in a 50°C, 20wt% HF solution for acid resistance testing. After 3-4 hours, the pH test paper on the UV film surface was observed. The test paper changed color, indicating acid seepage. The UV film separated from the protected surface. The UV film surface remained smooth and flat, without any signs of corrosion or blistering, indicating that the UV anti-tack protective film met the acid resistance requirements. However, due to low UV pre-adhesion and insufficient adhesion, the UV film detached from the protected surface, leading to acid seepage. The UV pre-adhesion needs to be adjusted.

[0043] In summary, the initial adhesion performance of Example 3 is 0-2# small balls, which meets the required performance. However, with low adhesion, the bonding strength cannot be guaranteed, causing the UV adhesive film to detach and fail to provide protection. Therefore, it is necessary to improve the adhesion.

[0044] Experimental Group 2: Selection of UV-active monomers Examples 5-9 The raw materials and their mass fractions for the preparation of Examples 5-9 are detailed in Table 3.

[0045] The performance test results of the products in Examples 5-9 are detailed in Table 4.

[0046] Table 3

[0047] Table 4

[0048] Example 5 uses the same resin formulation as in Example 3, but with the UV active monomer adjusted to DPHA (purchased from Shenzhen Zhongyue Chemical Co., Ltd.). The test sample size was 15 samples. The UV pre-adhesion was 400-800 g / 25 mm. There was no significant improvement in UV pre-adhesion, and no abnormality in tack reduction. Initial adhesion was 0-2# small balls. The prepared UV film was placed in a 50℃, 20wt% HF solution for acid resistance testing. After 1-2 hours, the pH test paper on the UV film surface was observed. The test paper changed color, indicating acid seepage. The UV film separated from the protected surface. The UV film surface remained smooth and flat, without any signs of corrosion or blistering, indicating that the UV adhesive met the acid resistance requirements. However, due to the low UV pre-adhesion and insufficient adhesion, the UV film detached from the protected surface, leading to acid seepage. The UV pre-adhesion needs adjustment.

[0049] In Example 6, using the same resin formulation as in Example 3, the UV active monomer was adjusted to PETA (purchased from Shenzhen Zhongyue Chemical Co., Ltd.). Fifteen samples were tested. The pre-UV adhesion was 1400-1800 g / 25 mm, with no significant increase in pre-UV adhesion and no abnormality in tack reduction. Initial adhesion was for 0-2# small balls. The prepared UV film was placed in a 50℃, 20wt% HF solution for acid resistance testing. After 4 hours, pH test paper on the UV film surface was observed. No discoloration, deformation, cracks, or other corrosion phenomena were found. The UV film surface remained smooth and flat, without any signs of corrosion, and its physical properties remained basically stable. This indicates that the UV film meets the acid resistance requirements while maintaining good physical properties.

[0050] In Example 7, using the same resin formulation as in Example 3, the UV active monomer was adjusted to 601Q (purchased from Changxing Materials Industry Co., Ltd.). Fifteen samples were tested. The pre-UV adhesion was 1600-1800 g / 25 mm, showing a significant improvement. No abnormalities were observed during tack reduction. Initial adhesion was achieved with 0-2# small balls. The prepared UV film was placed in a 50℃, 20wt% HF solution for acid resistance testing. After 4 hours, pH test paper on the UV film surface was observed. No discoloration, deformation, cracks, or other corrosion phenomena were found. The UV film surface remained smooth and flat, showing no signs of corrosion. Its physical properties remained basically stable, indicating that the UV film met acid resistance requirements while maintaining good physical properties. However, during the tack reduction and peeling process after acid soaking, the adhesive layer adhered to the glass, making tack reduction impossible.

[0051] In Example 8, using the same resin formulation as in Example 3, the UV active monomer was adjusted to BN4328 monomer (purchased from Baining New Materials). Fifteen samples were tested. The pre-UV adhesion was 1200-1400 g / 25 mm, showing a significant improvement. No abnormalities were observed during tack reduction. Initial adhesion was achieved with 0-2# small balls. The prepared UV film was placed in a 50℃, 20wt% HF solution for acid resistance testing. After 3-4 hours, pH test paper on the UV film surface was observed. The paper changed color, indicating acid seepage. The UV film partially separated from the protected surface. The UV film surface remained smooth and flat, without any signs of corrosion or blistering, indicating that the UV adhesive met the acid resistance requirements. However, insufficient adhesion caused the UV film to detach from the protected surface, leading to acid seepage. Adjustment to increase the pre-UV adhesion is necessary.

[0052] In Example 9, using the same resin formulation as in Example 3, the UV active monomer was adjusted to BN4332 monomer, with 15 test samples. The pre-UV adhesion was 1000-1300 g / 25 mm, showing a significant improvement. Adhesion reduction was normal, and initial adhesion was achieved with 0-2# small balls. The prepared UV film was placed in a 50°C, 20wt% HF solution for acid resistance testing. After 2-3 hours, pH test paper on the UV film surface was observed. The test paper changed color, indicating acid seepage. The UV film separated from the protected surface. The UV film surface remained smooth and flat, without any signs of corrosion or blistering, indicating that the UV adhesive met the acid resistance requirements. However, insufficient adhesion caused the UV film to detach from the protected surface, leading to acid seepage. Therefore, the pre-UV adhesion needs adjustment.

[0053] In summary, when 15 parts of PETA were added according to Example 6 under the above proportions, the adhesion was significantly increased and the acid resistance test was also qualified. However, there was a problem of residual adhesive before UV treatment. The analysis suggests that this was due to insufficient crosslinking agent, resulting in insufficient crosslinking degree. It is necessary to adjust the amount of crosslinking agent or use other crosslinking agents.

[0054] Experimental Group 3: Selection of Crosslinking Agent Examples 10-13 The raw materials and their mass fractions for the preparation of Examples 10-13 are detailed in Table 5.

[0055] The performance test results of the products in Examples 10-13 are detailed in Table 6.

[0056] Table 5

[0057] Table 6

[0058] Example 10: Following the formulation of Example 6, the amount of crosslinking agent N75 (purchased from Evonik Chemicals) added was changed to 2 parts. After coating, the tack before UV testing was 1200-1800 g / 25 mm, which was qualified. However, residual adhesive was found during the test. The tack reduction was normal, and the initial tack was 0-2# small balls. The prepared UV film was placed in a 50℃, 20wt% HF solution for acid resistance testing. After 4 hours, the pH test paper on the surface of the UV film was observed. No discoloration, deformation, cracks or other corrosion phenomena were found. The surface of the UV film remained smooth and flat, without any signs of corrosion. Its physical performance indicators also remained basically stable, indicating that the UV film met the acid resistance requirements; however, the presence of residual adhesive led to the conclusion that the crosslinking agent test was unqualified.

[0059] Example 11: Under the same formulation as in Example 6, the amount of crosslinking agent TT480 added was changed to 2 parts. After coating, the UV pre-adhesion was tested at 1200-1400 g / 25 mm, which was low. The tack reduction adhesion was normal. The initial adhesion was low for a 0# ball. The prepared UV film was placed in a 50℃, 20wt% HF solution for acid resistance testing. After 3 hours, the pH test paper on the UV film surface was observed. The test paper changed color, indicating acid seepage. The UV film separated from the protected surface. The UV film surface remained smooth and flat, without any signs of corrosion or bubbling, indicating that the UV adhesive met the acid resistance requirements. However, due to insufficient adhesion, the UV film detached from the protected surface, leading to acid seepage. The initial adhesion and UV pre-adhesion needed to be adjusted. Ultimately, the crosslinking agent was deemed unqualified.

[0060] Example 12: Under the same formulation as in Example 6, the amount of crosslinking agent IPDI (purchased from Evonik Chemicals) added was changed to 2 parts. After coating, the pre-UV adhesion was tested to be 1600-1900 g / 25 mm, which is qualified. The reduced adhesion was normal, and the initial adhesion was 0-2# small balls. The prepared UV film was placed in a 50℃, 20wt% HF solution for acid resistance testing. After 4 hours, the pH test paper on the surface of the UV film was observed. No discoloration, deformation, cracks or other corrosion phenomena were found. The surface of the UV film remained smooth and flat, without any signs of corrosion. Its physical properties remained basically stable, indicating that the UV film met the acid resistance requirements while maintaining good physical properties. The crosslinking agent test was qualified.

[0061] Example 13: Following the formulation of Example 6, the amount of crosslinking agent aluminum acetylacetonate (purchased from Evonik Chemicals) was changed to 2 parts. After coating, the adhesion before UV testing was 1500-1700 g / 25 mm, which was acceptable. However, residual adhesive was observed during the test. The adhesion after tack reduction was normal, and the initial adhesion was 0-2# small balls. The prepared UV film was placed in a 50℃, 20wt% HF solution for acid resistance testing. After 4 hours, the pH test paper on the surface of the UV film was observed. No discoloration, deformation, cracks, or other corrosion phenomena were found. The surface of the UV film remained smooth and flat, without any signs of corrosion. Ultimately, the crosslinking agent was deemed unqualified.

[0062] In summary, Example 12 is the optimal implementation case. The protective film has excellent adhesion and acid resistance, and leaves no residue after use, resulting in excellent practical performance.

Claims

1. A high-viscosity UV-resistant protective film resistant to strong acid corrosion, characterized in that, The raw materials for preparation, by mass parts, include 50-75 parts of high Tg acrylic UV resin, 25-50 parts of low Tg acrylic UV resin, 1-3 parts of photoinitiator, 10-20 parts of UV active monomer, 50-100 parts of solvent, and 1-3 parts of crosslinking agent. The high Tg acrylic UV resin has a weight-average molecular weight of 150,000-250,000 and a Tg of 20-30℃. The low-Tg acrylic UV resin has a weight-average molecular weight of 150,000-250,000 and a Tg of -10 to 0°C.

2. The high-viscosity UV-resistant protective film resistant to strong acid corrosion according to claim 1, characterized in that, The raw materials for preparing the high Tg acrylic UV resin include, by mass parts, 5-10 parts EHA, 10-20 parts BA, 10-20 parts MMA, 3-8 parts AA, 10-20 parts GMA, and 1-3 parts phase transfer catalyst.

3. The high-viscosity UV-resistant protective film resistant to strong acid corrosion according to claim 2, characterized in that, The phase transfer catalyst includes one of tetra-n-butylammonium bromide, tetra-n-butylammonium chloride, trioctylmethylammonium chloride, or tetraphenylphosphine bromide.

4. The high-viscosity UV-resistant protective film resistant to strong acid corrosion according to claim 2, characterized in that, In the raw materials for preparing the high Tg acrylic UV resin, the mass ratio of EHA, BA and MMA is 8:15:

15.

5. The high-viscosity UV-resistant protective film resistant to strong acid corrosion according to claim 1, characterized in that, The raw materials for preparing the low Tg acrylic UV resin include, by mass parts, 5-15 parts EHA, 20-40 parts BA, 5-10 parts MMA, 3-8 parts AA, 10-20 parts GMA, and 1-3 parts phase transfer catalyst.

6. The high-viscosity UV-resistant protective film resistant to strong acid corrosion according to claim 5, characterized in that, In the raw materials for preparing the low Tg acrylic UV resin, the mass ratio of EHA, BA and MMA is 10:30:

8.

7. The high-viscosity UV-resistant protective film resistant to strong acid corrosion according to claim 1, characterized in that, The photoinitiator includes one of TPO, 184 initiator, 1173 initiator, benzophenone, or 2-isopropylthioxanthrone.

8. The high-adhesion UV-resistant protective film resistant to strong acid corrosion according to any one of claims 1-7, characterized in that, The UV-active monomers include one or more of DPHA, PETA, 601Q, BN4328 monomers, or BN4332 monomers.

9. The high-viscosity UV-resistant protective film resistant to strong acid corrosion according to claim 1, characterized in that, The crosslinking agent includes one of IPDI, N75 crosslinking agent, TT480 crosslinking agent, or aluminum acetylacetonate.

10. A method for preparing a high-viscosity UV-resistant protective film resistant to strong acid corrosion according to any one of claims 1-9, characterized in that, Includes the following steps: High-Tg acrylic UV resin, low-Tg acrylic UV resin, photoinitiator, UV active monomer, solvent, and crosslinking agent are mixed evenly, then coated and cured to obtain a high-viscosity UV anti-tack protective film resistant to strong acid corrosion.

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