Protective film with microstructure

Abstract

The application relates to a protective film with a microstructure, the protective film is composed of a base material layer and a pressure-sensitive adhesive layer, and the surface of the protective film is provided with a unique prism microstructure. The prism microstructure is composed of a plurality of prism bodies which are tightly arranged and are consistent in arrangement direction, more discharge channels are provided for air due to the existence of the prism microstructure, bubbles between a protected surface and the protective film are effectively prevented from being generated when the protective film is attached, and adhesive force and residual glue are reduced when the protective film is torn off. By reasonably controlling the bottom width and the height of the prism body, the balance of the adhesive force and the separation performance of the pressure-sensitive adhesive layer is realized, so that the adhesive force is enough, and meanwhile, the good separation performance can be kept during tearing. The utility model further provides a method for manufacturing the protective film with the microstructure, the shape and the size of the prism microstructure can be accurately copied to the pressure-sensitive adhesive layer through the groove, corresponding to the prism microstructure, in the transfer printing substrate, and the requirements of different application scenes for microstructure precision are met.

Description

Technical Field

[0001] This application relates to the field of protective film technology, and more particularly to a protective film with a microstructure. Background Technology

[0002] Protective films, as functional thin film products with pressure-sensitive adhesives coated and cured on the surface of a substrate, play an important role in industrial production and daily life. Depending on the application, they can be applied with or without a release film. Common types of protective films are diverse, including polyurethane protective films, silicone protective films, acrylic protective films, and rubber protective films.

[0003] The core application of protective films is to provide temporary protection for glass, steel plates, plastic products, and wafers, preventing them from being contaminated and scratched during processing, transportation, or storage. This requires protective films to possess two key properties: firstly, they must be able to easily adhere to the product surface without producing defects such as bubbles, indentations, or wrinkles; secondly, they must be able to detach from the protected surface without leaving any residue when needed.

[0004] Currently, some progress has been made in the field of protective film technology. For example, some products have improved the adhesion and peel performance of protective films to a certain extent by using specific materials and processes. However, existing flat protective films still have many problems in practical applications. When flat protective films are applied to the surfaces of products such as glass, steel plates, and wafers, defects such as bubbles, indentations, or wrinkles can damage the protective effect on the product surface, potentially leaving surface defects from the manufacturing or usage process. More seriously, these defects can also lead to adhesive residue, which can severely affect the yield of these products in subsequent processes.

[0005] In the past, to address the issue of air bubbles during protective film application, some products were developed that used embossing to create microstructures for easier air release. However, these products had a relatively singular design purpose, merely improving air release during application and failing to comprehensively address other issues that might arise during application, such as indentations and wrinkles, as well as potential residue problems upon removal. Therefore, developing a protective film with microstructures and its manufacturing method to simultaneously solve multiple problems in both application and removal has become a crucial and pressing issue in the field of protective film technology. Utility Model Content

[0006] This application aims to provide a protective film product with a microstructure and its manufacturing method. The protective film features a prism microstructure, which enhances venting efficiency and reduces adhesive residue. The microchannels formed by its special microstructure possess directional venting characteristics and facilitate rapid penetration of gaseous or liquid materials for specific applications. Furthermore, the protective film is manufactured using a specific process to meet practical application requirements. The objective of this application is achieved through the following technical solution: the protective film with a microstructure comprises a substrate layer and a pressure-sensitive adhesive layer, wherein the pressure-sensitive adhesive layer includes a prism microstructure on one side opposite the substrate layer.

[0007] The prism microstructure includes multiple prism bodies arranged together, the prism bodies are arranged in the same direction, and the cross-sectional shape of the prism bodies is trapezoidal, isosceles triangle or arc.

[0008] The bottom width of the prism body is in the range of 5-100μm, and the height of the prism body is in the range of 0.3-1 times the bottom width of the prism body.

[0009] In one embodiment, the thickness of the substrate layer is in the range of 20-500 μm.

[0010] In one embodiment, the prism microstructures are arranged in the same direction as the protective film is torn off.

[0011] In one embodiment, the material of the substrate layer is selected from one or more of PC, PET, PI, PP, PE, TAC, or SRF;

[0012] The material of the pressure-sensitive adhesive layer is selected from one or more of acrylic pressure-sensitive adhesive, silicone pressure-sensitive adhesive, polyurethane pressure-sensitive adhesive, and rubber pressure-sensitive adhesive.

[0013] In one embodiment, the prism body cross-sectional shape includes rounded corners.

[0014] In one embodiment, an antistatic layer is further included, the antistatic layer being disposed on the side of the substrate layer opposite to the pressure-sensitive adhesive layer.

[0015] In one embodiment, a release film is also included.

[0016] This application also provides a method for fabricating a protective film with a microstructure, comprising the following steps:

[0017] Provide substrates and UV-curable pressure-sensitive adhesives;

[0018] Liquid pressure-sensitive adhesive is coated onto a transfer substrate, wherein the transfer substrate includes grooves corresponding to the prism microstructure;

[0019] Pressure-sensitive adhesive is coated onto the surface of a substrate using a transfer printing method.

[0020] The pressure-sensitive adhesive coated on the substrate surface is cured by light exposure and photocuring to form a pressure-sensitive adhesive layer including prism microstructures.

[0021] In one embodiment, the depth of the groove is in the range of 0.3 to 1 times the width of the groove.

[0022] In one embodiment, the transfer substrate is a light-transmitting substrate, and the pressure-sensitive adhesive is photocured by irradiating light through the light-transmitting substrate during the transfer process.

[0023] Compared with the prior art, this application has the following beneficial effects:

[0024] Improved exhaust and residue reduction due to microstructure

[0025] The microstructured protective film product of this application features a prism microstructure. This specific microstructure design enhances the air venting effect of the protective film. During actual application, when the protective film contacts the surface being protected, the gaps between the prism microstructures quickly guide air out, effectively preventing the formation of air bubbles. Compared to previous products that only achieved air venting through embossing of microstructures, the prism microstructure of this application can vent air more efficiently, significantly improving application efficiency and quality.

[0026] Meanwhile, due to the special design of the prism microstructure, the contact area and adhesion between the adhesive layer and the protected surface are reduced when the protective film is peeled off, allowing the protective film to be easily peeled off without residue. This characteristic is particularly important for products with extremely high surface quality requirements, such as protective glass, steel plates, and wafers, effectively avoiding surface defects caused by adhesive residue and improving the yield of the product in the next process.

[0027] The unique microstructure of the protective film in this application forms microchannels. During the process protection, when gaseous or liquid materials need to rapidly penetrate to the protected surface, the microchannels can act as material transport channels, guiding the material to the protected area quickly and uniformly, thus enabling the protective film to function reactively and meeting the needs of special application scenarios. The prism cross-section shape includes rounded corners, which improves the durability of the protective film. The presence of the antistatic layer effectively prevents the protective film from attracting dust and impurities due to static electricity during use, maintaining the cleanliness of the protective film and further enhancing the protective effect on the protected surface.

[0028] The method for manufacturing a microstructured protective film provided in this application involves coating a liquid pressure-sensitive adhesive onto a transfer substrate with grooves corresponding to the prism microstructure, then transferring the pressure-sensitive adhesive onto the substrate surface via a transfer process, and finally photocuring to form a pressure-sensitive adhesive layer including the prism microstructure. The grooves in the transfer substrate corresponding to the prism microstructure ensure that the pressure-sensitive adhesive layer forms a precise prism microstructure, guaranteeing product consistency and stability. The combination of transfer and photocuring enables rapid and efficient production of the protective film, improving production efficiency and reducing production costs.

[0029] In summary, the protective film product with microstructure and the manufacturing method of this application have advantages in terms of air venting effect, residual adhesive control, realization of special functions, production efficiency and quality through new technical features and processes. They can effectively solve the problems existing in the existing protective film technology and meet the market demand for high-performance protective films. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of the structure of a protective film with microstructure in one embodiment of this application;

[0031] Figure 2 This is a schematic diagram of the structure of a protective film with a microstructure in another embodiment of this application;

[0032] Figure 3 This is a schematic diagram of the structure of a protective film with a microstructure in another embodiment of this application.

[0033] Explanation of reference numerals in the attached drawings: 100, substrate layer; 200, pressure-sensitive adhesive layer; 300, release film. Detailed Implementation

[0034] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application will be described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, it should be noted that, for ease of description, only the parts relevant to this application are shown in the accompanying drawings, not the entire structure. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this application.

[0035] The terms “comprising” and “having”, and any variations thereof, used in this application are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not limited to the steps or units listed, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to such process, method, product, or apparatus.

[0036] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0037] In the field of industrial production and product protection, protective films play an irreplaceable role as an important functional material. They are usually made by coating a substrate surface with a cured pressure-sensitive adhesive. Depending on the actual needs, a release film can be applied or not. They are widely used for temporary protection of products such as glass, steel plates, plastic products, and wafers to prevent these products from being contaminated and scratched during processing, transportation, and storage.

[0038] Common protective films come in a wide variety of types, such as polyurethane, silicone, acrylic, and rubber protective films. However, existing flat protective films still have many drawbacks in practical applications. When applied to a product surface, they are prone to defects such as bubbles, indentations, or wrinkles. This not only compromises the protective effect on the product surface, leaving defects from the manufacturing process or during use, but may also leave adhesive residue, severely impacting the yield of the product in subsequent processes. While some products have previously improved air permeability by embossing microstructures, their function is relatively limited and cannot comprehensively solve the various problems encountered during the application and removal of protective films.

[0039] To address the aforementioned challenges, this application proposes a protective film with a microstructure and its fabrication method. The microstructure design of this protective film offers advantages, and its fabrication method is characterized by high efficiency and precision. The specific structure, technical features, and corresponding fabrication method of this microstructured protective film will be described in detail below. Please refer to... Figures 1 to 3 As shown, in a preferred embodiment of this application, the protective film with a microstructure includes a substrate layer 100 and a pressure-sensitive adhesive layer 200. The pressure-sensitive adhesive layer 200 includes a prism microstructure on one side opposite to the substrate layer 100. The prism microstructure includes a plurality of prisms arranged together, the prisms being arranged in the same direction, and the cross-sectional shape of the prisms being trapezoidal, isosceles triangle, or arc. The base width of the prisms is in the range of 5-100 μm, and the height of the prisms is in the range of 0.3-1 times the base width of the prisms.

[0040] The protective film with a microstructure mainly consists of a substrate layer 100 and a pressure-sensitive adhesive layer 200. The pressure-sensitive adhesive layer 200 is disposed on one side of the substrate layer 100, and it possesses a unique prism microstructure relative to the surface of the substrate layer 100. This prism microstructure is composed of multiple closely arranged prisms, all with the same orientation. The cross-sectional shape of the prisms is diverse, including trapezoids, isosceles triangles, or arcs. In terms of dimensions, the base width of the prisms is precisely controlled within the range of 5-100 μm, while the height of the prisms is determined based on their base width, specifically 0.3-1 times the base width.

[0041] The presence of prism microstructures provides more channels for air to escape. When the protective film is attached to the surface being protected, air can quickly escape through the gaps between the prisms, effectively preventing the formation of air bubbles. For example, when attaching large glass plates, traditional planar protective films may form multiple air bubbles because air cannot escape in time, affecting the protective effect. However, the protective film with prism microstructures in this application, due to the gap design between its prisms, allows air to escape more smoothly, greatly improving the quality and efficiency of attachment. The prisms are aligned in the same direction, giving the air a certain directionality during escape, further accelerating the exhaust speed, reducing air resistance during the exhaust process, and ensuring that the protective film can be quickly and smoothly attached to the surface being protected.

[0042] The unique shape and size design of the prism microstructure alters the contact method between the pressure-sensitive adhesive layer 200 and the protected surface. When the protective film is peeled off, the gaps between the prisms reduce the contact area between the adhesive layer and the protected surface, thereby reducing adhesion. For example, when peeling off a traditional planar protective film, residue may be left because the adhesive layer adheres tightly to the protected surface. However, with the protective film of this application, due to the prism microstructure, the adhesive layer is more easily separated from the protected surface, reducing residue and avoiding surface defects and subsequent cleaning hassles caused by residue.

[0043] The base width and height of the prism are calculated to ensure that the pressure-sensitive adhesive layer 200 has sufficient adhesion while maintaining good detachment performance upon removal. If the prism is too high or the base width is too large, the adhesion of the pressure-sensitive adhesive layer 200 may be too strong, increasing the risk of residual adhesive; conversely, if the prism is too low or the base width is too small, it may affect the adhesion of the protective film. This application achieves a balance between adhesion and detachment performance by reasonably controlling the size of the prism.

[0044] Prism shapes in various cross-sectional forms (trapezoidal, isosceles triangular, or arc-shaped) can adapt to different protected surfaces and adhesion requirements. For example, for objects with rough surfaces, trapezoidal prisms may offer better adhesion and venting; while for applications requiring high-precision adhesion, arc-shaped prisms may reduce damage to the protected surface. This diverse design allows for a wider range of applications, meeting the needs of different industries and application scenarios. The range of prism base width and height also takes into account the size and performance requirements of different products. For small, precision products, smaller prism sizes can provide finer protection and adhesion; while for large products, appropriately increasing the prism size can improve venting speed and adhesion efficiency. By flexibly adjusting the prism size, the protective film can better adapt to the protection needs of various products.

[0045] When the thickness of the substrate layer 100 is within the range of 20-500 μm, it can provide sufficient mechanical strength for the protective film. During the application, transportation, and use of the protective film, it is inevitably subjected to various external forces, such as stretching, bending, and friction. If the substrate layer 100 is too thin, it may not be able to withstand these external forces, leading to cracking or damage to the protective film and thus losing its protective function on the protected surface. The thickness range of the substrate layer 100 in this application provides it with sufficient toughness and strength to effectively resist damage from external forces, ensuring the integrity and durability of the protective film.

[0046] A suitable thickness also helps the substrate layer 100 maintain good flexibility. For products that need to be attached to curved or irregular surfaces, such as automotive parts and curved housings of electronic devices, the substrate layer 100 needs to have a certain degree of flexibility to adhere tightly. The aforementioned thickness range allows the substrate layer 100 to maintain sufficient strength while adapting to a certain degree of bending and deformation, ensuring that the protective film can perfectly adhere to surfaces of various shapes and provide comprehensive protection. Different products have different requirements for the thickness of the protective film. For some precision electronic products, such as wafers and chips, a thinner protective film is needed to reduce the impact on product size and performance while ensuring sufficient protection. In this case, the thickness of the substrate layer 100 can be controlled within the range of 20-100μm, which meets the requirements of thinness and provides necessary protection. For some large industrial products, such as steel plates and glass plates, a thicker protective film is needed to withstand greater external forces and provide better cushioning protection. The thickness of the substrate layer 100 can be selected within the range of 200-500μm. Therefore, the thickness range of 20-500μm makes this protective film widely adaptable to various applications, meeting the protection needs of different industries and products.

[0047] When the protective film needs to be removed, the prism microstructures, aligned with the tearing direction, create a synergistic effect, making the removal process smoother and more efficient. In practice, whether removed manually or using automated equipment, this arrangement offers advantages, effectively preventing damage to the protected surface caused by improper removal. When the prism microstructures are aligned with the tearing direction of the protective film, the shape and arrangement of the prisms guide the direction of the tearing force, distributing it more evenly across the protective film. With traditional protective films, due to their irregular structure, the tearing force may concentrate in certain localized areas, leading to increased tearing resistance and requiring considerable force to remove the film. However, the arrangement described in this application allows the tearing force to be smoothly transmitted along the direction of the prism microstructures, reducing localized stress concentration and thus lowering tearing resistance. The unique shape of the prism microstructure also helps reduce the contact area and adhesion between the protective film and the protected surface. During removal, the gaps between the prisms allow air to enter more easily, disrupting the adhesion between the adhesive layer and the protected surface, further reducing removal resistance. This effect is particularly important when removing protective films from products with extremely high surface requirements, such as wafers and precision optical components, effectively preventing surface scratches or adhesive residue caused by excessive removal resistance.

[0048] The reduced tearing resistance decreases the force exerted on the protected surface during film removal. For fragile surfaces such as plastics and coated surfaces, excessive tearing force can cause scratches, peeling, and other damage. The arrangement of the prism microstructures in this application, aligned with the tearing direction, makes the tearing process gentler and effectively protects the integrity of the protected surface. For example, when removing a protective film from automotive paint, it avoids scratches caused by excessive tearing force, preserving the paint's appearance and quality. Furthermore, this arrangement reduces static electricity and frictional heat generated during the tearing process. Static electricity and frictional heat can damage sensitive protected surfaces; for example, electronic components may be damaged by static electricity, and some heat-sensitive materials may deform due to frictional heat. By reducing tearing resistance and making the tearing process smoother, the generation of static electricity and frictional heat is reduced, further improving the protective effect on the protected surface. In industrial production, the efficiency of protective film removal directly impacts production schedule and cost. The prism microstructure's alignment with the removal direction makes the removal process faster and more efficient. Whether manually operated or on an automated production line, removing the protective film can be completed more easily. For example, in the assembly of electronic products, the protective film needs to be quickly removed to proceed to the next step. Using the protective film of this application significantly improves removal efficiency, reduces production time, and increases overall production efficiency. Simultaneously, this efficient removal method also helps reduce the defect rate caused by improper removal. Because the removal process is smoother, it reduces problems such as film tearing and residue caused by removal difficulties, ensuring product quality and stability. For large-scale production enterprises, reducing the defect rate can significantly improve economic benefits and market competitiveness.

[0049] In the microstructured protective film, the substrate layer 100 serves as the supporting foundation for the entire protective film. Its material is carefully selected from one or more of polycarbonate (PC), polyethylene terephthalate (PET), polyimide (PI), polypropylene (PP), polyethylene (PE), cellulose triacetate (TAC), or synthetic rubber foam (SRF). Each of these materials possesses unique physical and chemical properties, meeting the diverse needs of the substrate layer 100 in different application scenarios. The pressure-sensitive adhesive layer 200, which enables the protective film to adhere to the protected surface, is made from one or more of acrylic pressure-sensitive adhesive, silicone pressure-sensitive adhesive, polyurethane pressure-sensitive adhesive, and rubber pressure-sensitive adhesive. Different types of pressure-sensitive adhesives possess different adhesion characteristics, temperature resistance, chemical resistance, and other properties, allowing for rational selection based on the material of the protected surface, the usage environment, and specific application requirements. This diverse combination of materials makes the microstructured protective film more widely applicable.

[0050] In protective films with microstructures, all angles within the prism's cross-sectional shape are designed as rounded corners. At the microscopic level, the presence of these rounded corners alters the geometric properties of the prism surface, causing it to exhibit different mechanical and optical behaviors compared to traditional sharp edges when in contact with other objects. In practical applications, this rounded corner design enhances the performance of the protective film, offering unique advantages during application, use, and removal, providing more comprehensive and reliable protection for the protected surface. The rounded corner design also results in a more uniform stress distribution on the prism surface, preventing stress concentration. Furthermore, the rounded corners allow the prism to better conform to the microscopic unevenness of the protected surface when in contact. The surfaces being protected typically have a certain degree of roughness. When a prism with sharp edges comes into contact with these microscopic irregularities, gaps or incomplete adhesion may occur, leading to air residue or poor contact between the adhesive layer and the protected surface. The rounded corners design allows the prism to more easily fill these microscopic gaps, increasing the contact area between the adhesive layer and the protected surface, and improving the tightness of the adhesion. During the application process, the rounded corners also reduce the friction between the prism and the protected surface, making it easier for the protective film to slide and adjust its position, thus improving the efficiency and accuracy of the application.

[0051] This microstructured protective film incorporates an antistatic layer in its structural design. This antistatic layer is precisely positioned on the side of the substrate layer 100 opposite the pressure-sensitive adhesive layer 200, at the outermost layer of the protective film. As the interface between the protective film and the external environment, the antistatic layer plays a crucial protective role. It effectively addresses static electricity issues arising from friction and contact during the production, storage, transportation, and use of the protective film, providing comprehensive and multi-layered protection for the protected product and ensuring that the product is protected from potential hazards caused by static electricity at every stage.

[0052] Specifically, it also includes a release film 300. As an important component of the protective film, the release film 300 effectively prevents the pressure-sensitive adhesive layer 200 from unnecessary adhesion to other objects during the production stage of the protective film, ensuring that the adhesion performance of the pressure-sensitive adhesive is not affected. During storage and transportation, the release film 300 protects the pressure-sensitive adhesive layer 200 from contamination by dust, impurities, etc., maintaining the cleanliness of the pressure-sensitive adhesive. When in use, it can be easily peeled off from the protective film, allowing the protective film to be smoothly adhered to the protected surface. The thickness of the release film 300 is in the range of 30-80μm. This thickness design gives the release film 300 both sufficient strength and easy peeling from the protective film.

[0053] This application also provides a method for manufacturing a protective film with a microstructure, comprising the following steps: providing a substrate and a photocurable pressure-sensitive adhesive; coating a liquid pressure-sensitive adhesive onto a transfer substrate, wherein the transfer substrate includes grooves corresponding to prism microstructures; coating the pressure-sensitive adhesive onto the surface of the substrate by a transfer method; subjecting the substrate to light irradiation; and curing the pressure-sensitive adhesive coated on the surface of the substrate by a photocuring method to form a pressure-sensitive adhesive layer 200 including prism microstructures.

[0054] First, prepare the substrate and the UV-curable pressure-sensitive adhesive. The substrate, as the supporting base of the protective film, directly affects the overall quality and performance of the film and must be strictly selected according to the specific application scenario. The UV-curable pressure-sensitive adhesive, with its rapid curing and excellent adhesion properties, is a key material for achieving adhesion between the protective film and the protected surface. Next, the liquid pressure-sensitive adhesive is uniformly coated onto the transfer substrate, which contains grooves corresponding to the prism microstructure. The precision and shape of these grooves directly determine the quality and characteristics of the prism microstructure on the final pressure-sensitive adhesive layer 200. During the coating process, the amount and uniformity of the liquid pressure-sensitive adhesive must be precisely controlled to ensure that the adhesive fully fills the grooves on the transfer substrate, laying the foundation for the subsequent transfer process.

[0055] Then, the pressure-sensitive adhesive is precisely coated onto the substrate surface using a transfer method. This transfer process requires specialized equipment and precise process parameter control to ensure the adhesive is completely transferred from the transfer substrate to the substrate surface while maintaining the shape and precision of the prism microstructure. During the transfer process, care must be taken to avoid defects such as bubbles and wrinkles in the adhesive to ensure the quality of the adhesive layer 200. Next, the adhesive coated on the substrate surface is subjected to light treatment. By selecting appropriate light sources and parameters, such as light intensity and duration, the adhesive undergoes a chemical reaction under light, rapidly curing to form an adhesive layer 200 with certain strength and adhesion properties. The light treatment process must be carried out under specific environmental conditions to avoid the influence of external factors on the curing effect. This forms an adhesive layer 200 containing a prism microstructure. This adhesive layer 200 not only possesses the adhesion function of ordinary pressure-sensitive adhesives but also exhibits special optical or physical properties due to its unique prism microstructure, such as anti-reflection, anti-reflection, and light guiding, providing more comprehensive and efficient protection for the protected surface.

[0056] By utilizing the grooves in the transfer substrate corresponding to the prism microstructure, the shape and size of the prism microstructure can be replicated onto the pressure-sensitive adhesive layer 200. This ensures the consistency and accuracy of the prism microstructure on the pressure-sensitive adhesive layer 200, meeting the precision requirements of microstructures in different application scenarios. For example, in the field of optics, precise prism microstructures can improve the optical performance of optical components and reduce light loss and interference. By adjusting the shape and size of the grooves in the transfer substrate, the parameters of the prism microstructure on the pressure-sensitive adhesive layer 200, such as the prism height, angle, and spacing, can be easily controlled. This structural controllability allows the fabrication method to customize prism microstructures with specific performance according to different needs, improving the versatility and applicability of the protective film.

[0057] The use of photocurable pressure-sensitive adhesive allows the pressure-sensitive adhesive layer 200 to cure in a short time, which can greatly shorten the production cycle and improve production efficiency. In large-scale production, this rapid curing characteristic can reduce production costs. Applying the pressure-sensitive adhesive to the substrate surface through transfer printing ensures a uniform distribution of the thickness and adhesion of the pressure-sensitive adhesive layer 200. A uniform pressure-sensitive adhesive layer 200 provides more reliable adhesion performance, allowing the protective film to adhere firmly to the protected surface, reducing the likelihood of peeling or poor local adhesion.

[0058] Specifically, the depth of the groove is in the range of 0.3 to 1 times the width of the groove. The ratio of groove depth to width has a crucial impact on the subsequent filling and transfer of pressure-sensitive adhesive and the performance of the final prism microstructure. A suitable depth-to-width ratio ensures that the pressure-sensitive adhesive is fully filled in the groove and completely and accurately replicated to the substrate surface during the transfer process, thereby forming a high-quality and high-performance prism microstructure pressure-sensitive adhesive layer 200.

[0059] In the fabrication method of protective films with microstructures, a light-transmitting substrate is used for transfer. This substrate possesses excellent optical transmittance, allowing light to pass through and illuminate the pressure-sensitive adhesive (PSA) simultaneously with the transfer step, thus achieving photocuring of the PSA. During the transfer process, as the PSA is transferred from the transfer substrate to the substrate surface, light precisely targets the PSA, enabling it to complete the curing reaction in a short time. This simultaneous transfer and photocuring operation not only improves production efficiency but also ensures the uniformity and consistency of the PSA's curing effect. Conventional PSA curing methods typically involve a separate photocuring step after transfer, requiring the transferred substrate to be transferred to specialized photocuring equipment, increasing production steps and time costs. However, by using a light-transmitting substrate for simultaneous photocuring, two previously independent steps are combined into a continuous process, significantly shortening the production cycle. For example, in the large-scale production of protective films with microstructures, this simultaneous operation can significantly increase output per unit time, reduce production costs, and improve the company's economic benefits. Specific Implementation

[0061] The following will further introduce some specific implementation methods to provide a more detailed explanation of the technical solution of this application.

[0062] Example 1

[0063] A microstructured protective film was prepared by applying pressure-sensitive adhesive to a 50μm PET surface via microstructure transfer and then photocuring to form a prism strip microstructured pressure-sensitive adhesive coating. The pressure-sensitive adhesive is one of polyurethane, acrylic, silicone, or rubber, with polyurethane being preferred. The prism structure is an isosceles triangle with a base width of 50μm and a prism height of 25μm.

[0064] Example 2

[0065] A microstructured protective film was prepared by applying pressure-sensitive adhesive to a 50μm PET surface via microstructure transfer and then photocuring to form a prism strip microstructured pressure-sensitive adhesive coating. The pressure-sensitive adhesive is one of polyurethane, acrylic, silicone, or rubber, with polyurethane being preferred. The prism structure is an isosceles triangle with a base width of 50μm and a prism height of 10μm.

[0066] Example 3

[0067] A microstructured protective film was prepared by applying pressure-sensitive adhesive to a 50μm PET surface via microstructure transfer and then photocuring to form a prism strip microstructured pressure-sensitive adhesive coating. The pressure-sensitive adhesive is one of polyurethane, acrylic, silicone, or rubber, with polyurethane being preferred. The prism structure is an isosceles triangle with a base width of 50μm and a prism height of 60μm.

[0068] Comparative Example 1

[0069] The comparative example is a typical exhaust film, which does not have a prism structure.

[0070]

[0071] Compared to conventional protective membranes, microstructured protective membranes exhibit lower peel strength. Furthermore, microstructured protective membranes can possess directionally selective peel strength. In addition, microstructured protective membranes demonstrate unique permeability, simultaneously providing surface protection and rapid permeation to the protected surface. When the microstructure height is less than 0.3 times its width, the permeation rate is affected. When the microstructure height is greater than 1 times its width, the adhesion is poor, and there is a risk of spontaneous detachment.

[0072] As described above, this application provides a protective film with a microstructure. This protective film consists of a substrate layer and a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer is disposed on one side of the substrate layer, and its surface relative to the substrate layer has a unique prism microstructure. The prism microstructure is composed of multiple closely arranged prisms, all of which are aligned in the same direction. The cross-sectional shape can be trapezoidal, isosceles triangle, or arc. The presence of the prism microstructure provides more channels for air to escape. When the protective film is attached to the protected surface, air can quickly escape through the gaps between the prisms, effectively preventing the formation of air bubbles. For example, when attaching large glass plates, traditional planar protective films may form air bubbles because air cannot escape in time, affecting the protective effect. The protective film with the prism microstructure of this application, however, ensures a smooth and bubble-free attachment.

[0073] The prisms are aligned in the same direction, giving the air a directional quality during exhaust, further accelerating the exhaust speed and reducing resistance during air expulsion. The special shape and size design of the prism microstructure alters the contact pattern between the pressure-sensitive adhesive layer and the protected surface. When the protective film is peeled off, the gaps between the prisms reduce the contact area between the adhesive layer and the protected surface, thereby reducing adhesion and minimizing adhesive residue.

[0074] The prism's base width and height ensure that the pressure-sensitive adhesive layer possesses sufficient adhesion while maintaining good peelability, achieving a balance between adhesion and peel performance. Prisms with various cross-sectional shapes (trapezoidal, isosceles triangle, or arc shape) can adapt to different protected surfaces and application requirements. For example, trapezoidal prisms may be more suitable for rough surfaces, while arc-shaped prisms are better suited for applications requiring high-precision application. The range of prism base width and height also takes into account the size and performance requirements of different products, enabling the protective film to be widely used in various products. When the protective film needs to be removed, the alignment of the prism microstructures with the tearing direction creates a synergistic effect, making the tearing process smoother and more efficient. This arrangement not only reduces tearing resistance but also minimizes damage to the protected surface, improving production efficiency and product quality.

[0075] This application also provides a method for fabricating a protective film with a microstructure. This method involves transferring the microstructure onto a translucent substrate and simultaneously curing the pressure-sensitive adhesive by irradiating the substrate with light. This simultaneous transfer and curing operation not only improves production efficiency but also ensures the uniformity and consistency of the pressure-sensitive adhesive's curing effect. By utilizing the grooves in the transfer substrate corresponding to the prism microstructure, the shape and size of the prism microstructure can be precisely replicated onto the pressure-sensitive adhesive layer, meeting the microstructure precision requirements of different application scenarios.

[0076] The above is only one specific implementation of this application, and any other improvements made based on the concept of this application shall be considered within the scope of protection of this application.

Claims

1. A protective film having a microstructure, characterized by, The prism microstructure includes a plurality of prism bodies arranged together, the prism bodies have the same arrangement direction, and the cross-sectional shape of the prism bodies is trapezoidal, isosceles triangular or circular arc-shaped. The bottom width of the prism body is in the range of 5-100 μm, and the height of the prism body is in the range of 0.3-1 times the bottom width of the prism body. The thickness of the substrate layer is in the range of 20-500 μm.

2. The protective film having a microstructure according to claim 1, wherein The arrangement direction of the prism microstructure is the same as the peeling direction of the protective film.

3. The protective film having a microstructure according to claim 1, wherein The prism body cross-sectional shape includes a circular arc angle.

4. The protective film having a microstructure according to claim 1, wherein An antistatic layer is further included, and the antistatic layer is arranged on the side of the substrate layer opposite to the side of the pressure-sensitive adhesive layer.

5. The protective film having a microstructure according to claim 1, wherein A release film is further included.

6. The protective film having a microstructure according to claim 1, wherein ​

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