Protective film with microstructure and manufacturing method thereof

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 invention 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] The present application relates to the technical field of protective films, and in particular to a protective film with a microstructure and a method for manufacturing the same. Background Art

[0002] As a functional film product with a cured pressure-sensitive adhesive coated on the surface of a substrate, protective film plays an important role in industrial production and daily life. Depending on the usage scenario, it can be attached with or without a release film. Common protective film product types are rich and varied, including polyurethane protective film, silicone protective film, acrylic protective film, and rubber protective film.

[0003] The core application of protective film is to provide temporary protection for glass, steel plates, plastic products and wafers to prevent them from being contaminated and scratched during processing, transportation or storage. This requires the protective film to have two key properties: on the one hand, it can be easily attached to the surface of the product when in use without causing bubbles, indentations or wrinkles; on the other hand, it can be detached from the protected surface without any residue when it needs to be torn off.

[0004] At present, certain progress has been made in the field of protective film technology. For example, some products have improved the adhesion and tearing properties of protective films to a certain extent by adopting specific materials and processes. However, existing flat protective films still have many problems in practical applications. When flat protective films are attached to the surfaces of products such as glass, steel plates, wafers, etc., once undesirable phenomena such as bubbles, indentations or wrinkles appear, the careful protection of the product surface will be destroyed, and it is very likely to leave surface defects on the product surface during the process or use. More seriously, these undesirable phenomena may also cause adhesive layer residues, which will seriously affect the yield of these products in the next process.

[0005] In the past, in order to solve the problem of bubbles generated when the protective film is attached, some products with embossed microstructures to create an easy-to-exhaust effect have appeared. However, the design purpose of such products is relatively simple, and is only limited to improving the exhaust performance when the protective film is attached. It fails to fully solve other problems such as indentations and wrinkles that may occur during the attachment process of the protective film, as well as the residue problem that may be generated when it is torn off. Therefore, the development of a protective film with a microstructure and its production method to simultaneously solve multiple problems in the process of attaching and tearing off the protective film has become an important issue that needs to be solved in the current field of protective film technology. Summary of the invention

[0006] The present application aims to provide a protective film product with a microstructure and a manufacturing method. The protective film is provided with a prismatic microstructure, which can enhance the exhaust effect and reduce residual adhesive. The microchannel formed by its special microstructure has directional exhaust characteristics and helps the rapid penetration of gas or liquid materials for special applications. At the same time, the protective film is manufactured through a specific process to meet the needs of practical applications. The purpose of this application is achieved through the following technical solutions. The protective film with a microstructure of the present application includes a substrate layer and a pressure-sensitive adhesive layer. The side of the pressure-sensitive adhesive layer opposite to the substrate layer includes a prismatic microstructure; The prismatic microstructure comprises a plurality of prism bodies arranged together, the prism bodies are arranged in the same direction, and the cross-sectional shape of the prism body is a trapezoid, an isosceles triangle or an arc; 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 of the bottom width of the prism body.

[0007] In one embodiment, the thickness of the substrate layer is in the range of 20-500 μm.

[0008] In one embodiment, the arrangement direction of the prism microstructure is the same as the tearing direction of the protective film.

[0009] In one embodiment, the material of the substrate layer is selected from one or more of PC, PET, PI, PP, PE, TAC or SRF; 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.

[0010] In one embodiment, the angles included in the cross-sectional shape of the prism body are all arc angles.

[0011] In one of the embodiments, an antistatic layer is further included, and the antistatic layer is disposed on a side of the substrate layer opposite to the pressure-sensitive adhesive layer.

[0012] In one embodiment, a release film is also included.

[0013] The present application also provides a method for manufacturing a protective film with a microstructure, comprising the following steps: Provide substrate and light-curing pressure-sensitive adhesive; Applying a liquid pressure-sensitive adhesive on a transfer substrate, wherein the transfer substrate includes grooves corresponding to the prism microstructures; The pressure-sensitive adhesive is applied to the surface of the substrate by transfer printing; The pressure-sensitive adhesive coated on the surface of the substrate is cured by light irradiation to form a pressure-sensitive adhesive layer including a prism microstructure.

[0014] In one of the embodiments, the depth of the groove is in the range of 0.3-1 times the width of the groove.

[0015] In one embodiment, the transfer substrate is a light-transmitting substrate, and light is irradiated through the light-transmitting substrate to photo-cure the pressure-sensitive adhesive during transfer.

[0016] Compared with the prior art, this application has the following beneficial effects: Improvement of exhaust and residual adhesive due to microstructure The microstructured protective film product of the present application is provided with a prismatic microstructure. The specific microstructure design enables the protective film to have an enhanced exhaust effect. During the actual attachment process, when the protective film contacts the protected surface, the gaps between the prismatic microstructures can quickly guide the air out, effectively avoiding the generation of bubbles. Compared with previous products that only use embossing to create a microstructure that is easy to exhaust, the prismatic microstructure of the present application can exhaust air more efficiently, greatly improving the efficiency and quality of attachment.

[0017] At the same time, due to the special design of the prism microstructure, when the protective film is peeled off, the contact area and adhesion between the adhesive layer and the protected surface can be reduced, so that the protective film can be easily peeled off without residue. This feature is especially important for products with extremely high surface quality requirements such as protective glass, steel plates, and wafers. It can effectively avoid surface defects caused by adhesive layer residues and improve the yield of the product in the next process.

[0018] The special microstructure of the protective film of this application forms a microchannel. During the process of process protection, when the gas or liquid phase material needs to quickly penetrate into the protected surface, the microchannel can serve as a channel for material transmission, guiding the material to quickly and evenly reach the protected area, realizing the reactive function in the protective film, and meeting the needs of special application scenarios. The angles included in the cross-sectional shape of the prism body are all arc angles, which can improve the durability of the protective film. The presence of the antistatic layer can effectively prevent the protective film from absorbing dust and impurities due to static electricity during use, maintain the cleanliness of the protective film, and further improve the protection effect on the protected surface.

[0019] The method for making a protective film with a microstructure provided in the present application is to apply a liquid pressure-sensitive adhesive to a transfer substrate with grooves corresponding to the prism microstructure, then apply the pressure-sensitive adhesive to the surface of the substrate by transfer, and finally perform light irradiation and photocuring to form a pressure-sensitive adhesive layer including a prism microstructure. The grooves corresponding to the prism microstructure in the transfer substrate can ensure that the pressure-sensitive adhesive layer forms a precise prism microstructure, ensuring the consistency and stability of the product. The combination of transfer and photocuring can quickly and efficiently complete the production of the protective film, thereby improving production efficiency and reducing production costs.

[0020] To sum up, the protective film product with microstructure and the manufacturing method of the present application have advantages in exhaust effect, residual glue control, special function realization, production efficiency and quality through new technical features and processes. It can effectively solve the problems existing in the existing protective film technology and meet the market demand for high-performance protective films. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic structural diagram of a protective film with a microstructure in one embodiment of the present application; Figure 2 is a schematic structural diagram of a protective film with a microstructure in another embodiment of the present application; Figure 3 It is a schematic structural diagram of a protective film with a microstructure in another embodiment of the present application.

[0022] Description of reference numerals: 100, substrate layer; 200, pressure-sensitive adhesive layer; 300, release film. DETAILED DESCRIPTION

[0023] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It is to be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some structures related to the present application are shown in the accompanying drawings, rather than all structures. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0024] The terms "including" and "having" and any variations thereof in this application are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device comprising a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units not listed, or may optionally include other steps or units inherent to these processes, methods, products or devices.

[0025] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0026] In the field of industrial production and product protection, protective film plays an irreplaceable role as an important functional material. It is usually made by coating a cured pressure-sensitive adhesive on the surface of a substrate. It can be attached or not attached with a release film according to actual needs. It is widely used in 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.

[0027] There are many types of common protective films, such as polyurethane protective films, silicone protective films, acrylic protective films and rubber protective films, but existing flat protective films still have many disadvantages in practical applications. When attached to the surface of the product, it is easy to produce bubbles, indentations or wrinkles, which will not only destroy the careful protection of the product surface, causing defects in the process or use on the product surface, but also may cause adhesive layer residues, seriously affecting the yield of the product in the next process. In the past, there were products that improved the air venting by embossing microstructures, but the function was relatively single and could not fully solve the various problems of the protective film during the attachment and removal process.

[0028] In order to solve the above problems, this application proposes a protective film with a microstructure and a method for making the same. The microstructure design of the protective film brings advantages, and the method for making the same also has the characteristics of high efficiency and precision. Next, the specific structure, technical features and corresponding method for making the protective film with a microstructure will be introduced in detail. Figures 1 to 3 As shown, a protective film with a microstructure in a preferred embodiment of the present application includes a substrate layer 100 and a pressure-sensitive adhesive layer 200, wherein the pressure-sensitive adhesive layer 200 includes a prismatic microstructure on a side opposite to the substrate layer 100, wherein the prismatic microstructure includes a plurality of prism bodies arranged together, wherein the prism bodies are arranged in the same direction, and wherein the cross-sectional shape of the prism bodies is a trapezoid, an isosceles triangle or an arc, wherein 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 of the bottom width of the prism body.

[0029] The protective film with a microstructure is mainly composed of a substrate layer 100 and a pressure-sensitive adhesive layer 200, wherein the pressure-sensitive adhesive layer 200 is arranged on one side of the substrate layer 100, and the surface of the pressure-sensitive adhesive layer 200 relative to the substrate layer 100 has a unique prismatic microstructure. This prismatic microstructure is composed of a plurality of closely arranged prisms, and the arrangement direction of all prisms is consistent. The cross-sectional shape of the prism is diverse and can be a trapezoid, an isosceles triangle or an arc. In terms of size, the bottom width of the prism is precisely controlled within the range of 5-100μm, and the height of the prism is determined according to its bottom width, specifically 0.3-1 times the bottom width of the prism.

[0030] The presence of the prismatic microstructure provides more exhaust channels for air. When the protective film is attached to the protected surface, the air can be quickly discharged along the gaps between the prism bodies, effectively avoiding the generation of bubbles. For example, when attaching a large glass plate, the traditional flat protective film may form multiple bubbles because the air cannot be discharged in time, affecting the protection effect. However, the protective film with a prismatic microstructure of the present application, due to the gap design between the prism bodies, can discharge air more smoothly, greatly improving the quality and efficiency of attachment. The prism bodies are arranged in the same direction, so that the air has a certain directionality when it is discharged, further speeding up the exhaust speed, reducing the resistance of the air during the discharge process, and ensuring that the protective film can be quickly and smoothly attached to the protected surface.

[0031] The special shape and size design of the prism microstructure changes the contact mode between the pressure-sensitive adhesive layer 200 and the protected surface. When the protective film is torn off, the gaps between the prism bodies can reduce the contact area between the adhesive layer and the protected surface, thereby reducing the adhesion. For example, when the protective film is torn off, the traditional flat protective film may leave residual adhesive because the adhesive layer is tightly fitted to the protected surface. However, due to the effect of the prism microstructure, the protective film of the present application makes it easier for the adhesive layer to separate from the protected surface, reducing the generation of residual adhesive and avoiding surface defects caused by residual adhesive and the trouble of subsequent cleaning.

[0032] The bottom width and height range of the prism body are calculated so that the pressure-sensitive adhesive layer 200 has sufficient adhesion while maintaining good detachment performance when peeled off. If the prism body is too high or the bottom 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 body is too low or the bottom width is too small, it may affect the attachment effect of the protective film. The present application achieves a balance between adhesion and detachment performance by reasonably controlling the size of the prism body.

[0033] Prisms with various cross-sectional shapes (trapezoidal, isosceles triangle or arc-shaped) can adapt to different protected surfaces and attachment requirements. For example, for protected objects with rougher surfaces, trapezoidal prisms may have better fit and exhaust effects; for occasions that require higher precision attachment, arc-shaped prisms may be able to reduce damage to the protected surface. The diversified design enables the protective film to have a wider range of applications and can meet the needs of different industries and application scenarios. The setting of the bottom width and height range of the prism also takes into account the size and performance requirements of different products. For small precision products, a smaller prism size can provide more sophisticated protection and attachment effects; for large products, appropriately increasing the prism size can increase the exhaust speed and attachment efficiency. By flexibly adjusting the size of the prism, the protective film can better adapt to the protection needs of various products.

[0034] When the thickness of the substrate layer 100 is in the range of 20-500μm, it can provide sufficient mechanical strength for the protective film. During the attachment, transportation and use of the protective film, it will inevitably be affected by various external forces, such as stretching, bending, friction, etc. If the substrate layer 100 is too thin, it may not be able to withstand these external forces, causing the protective film to rupture or be damaged, thereby losing its protective effect on the protected surface. The thickness range of the substrate layer 100 of the present application enables the substrate layer 100 to have sufficient toughness and strength, which can effectively resist damage from external forces and ensure the integrity and durability of the protective film.

[0035] The appropriate thickness also helps the substrate layer 100 maintain good flexibility. For some products that need to be attached to curved or irregular surfaces, such as automotive parts, curved housings of electronic equipment, etc., the substrate layer 100 needs to have a certain degree of flexibility to fit tightly. The above thickness range allows the substrate layer 100 to maintain sufficient strength while being able to adapt to a certain degree of bending and deformation, ensuring that the protective film can perfectly fit on surfaces of various shapes and provide comprehensive protection. Different products have different requirements for the thickness of the protective film. For some sophisticated electronic products, such as wafers, chips, etc., a thinner protective film is required to reduce the impact on product size and performance, while ensuring sufficient protection. At this time, the thickness of the substrate layer 100 can be controlled within the range of 20-100μm, which can not only meet the requirements of lightness and thinness, but also provide necessary protection. For some large industrial products, such as steel plates, glass plates, etc., a thicker protective film is required to withstand greater external forces and provide better buffer 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 the protective film adaptable to a wide range of applications and can meet the protection needs of different industries and different products.

[0036] When the protective film needs to be torn off, since the arrangement direction of the prism microstructure is the same as the tearing direction, a synergistic effect can be formed, making the tearing process smoother and more efficient. In actual operation, whether it is manually torn off or torn off with automated equipment, this arrangement method can play an advantage and effectively avoid damage to the protected surface caused by improper tearing. When the arrangement direction of the prism microstructure is the same as the tearing direction of the protective film, during the tearing process, the shape and arrangement of the prism body can guide the direction of the tearing force so that the tearing force is more evenly distributed on the protective film. When the traditional protective film is torn off, due to the irregularity of the structure, the tearing force may be concentrated in certain local areas, resulting in increased tearing resistance, and even requiring greater force to tear off the protective film. The arrangement method of the present application enables the tearing force to be smoothly transmitted along the direction of the prism microstructure, reducing local stress concentration, thereby reducing tearing resistance. The special shape of the prism microstructure also helps to reduce the contact area and adhesion between the protective film and the protected surface. When tearing off, the gaps between the prisms allow air to enter more easily, destroying the adhesion between the adhesive layer and the protected surface, further reducing the tearing resistance. This effect is particularly important when tearing off protective films of products with extremely high surface requirements, such as wafers and precision optical components, and can effectively avoid surface scratches or adhesive layer residues caused by excessive tearing resistance.

[0037] Due to the reduction in tearing resistance, the force on the protected surface when tearing off the protective film will also be reduced accordingly. For some products with fragile surfaces, such as plastic products, coated surfaces, etc., excessive tearing force may cause scratches, peeling and other damage to the surface. The arrangement of the prism microstructure in the same direction as the tearing direction in the present application makes the tearing process more gentle and can effectively protect the integrity of the protected surface. For example, when tearing off the protective film attached to the paint surface of a car, scratches on the paint surface caused by excessive tearing force can be avoided, maintaining the beauty and quality of the car paint surface. In addition, this arrangement can also reduce the static electricity and frictional heat generated during the tearing process. Static electricity and frictional heat may cause damage to certain sensitive protected surfaces, such as the surface of electronic components may be damaged by static electricity, and some heat-sensitive materials may be deformed due to frictional heat. By reducing the tearing resistance and making the tearing process smoother, the generation of static electricity and frictional heat is reduced, and the protection effect on the protected surface is further improved. In industrial production, the tearing efficiency of the protective film directly affects the production schedule and cost. The arrangement of the prism microstructure in the same direction as the tearing direction makes the tearing process faster and more efficient. Whether it is manual operation or an automated production line, the tearing of the protective film can be completed more easily. For example, in the assembly process of electronic products, the protective film needs to be quickly torn off to proceed to the next step. The use of the protective film of the present application can greatly improve the tearing efficiency, reduce production time, and improve production efficiency. At the same time, this efficient tearing method also helps to reduce the defective rate caused by improper tearing. Since the tearing process is smoother, the problems of tearing and residue of the protective film caused by the difficulty of tearing are reduced, and the quality and stability of the product are guaranteed. For some large-scale production enterprises, reducing the defective rate can significantly improve economic benefits and market competitiveness.

[0038] In the protective film with microstructure, the substrate layer 100 serves as the supporting basis of the entire protective film. Its material is carefully selected and is selected from one or more of polycarbonate (PC), polyethylene terephthalate (PET), polyimide (PI), polypropylene (PP), polyethylene (PE), triacetyl cellulose (TAC) or synthetic rubber foam (SRF). These materials each have unique physical and chemical properties and can meet the diverse needs of the protective film substrate layer 100 in different application scenarios. The pressure-sensitive adhesive layer 200, as the part that realizes the bonding function of the protective film and the protected surface, is selected 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 have different adhesion properties, temperature resistance, chemical resistance and other properties. They can be reasonably selected according to the material of the protected surface, the use environment and the specific application requirements. The diversified material selection combination makes the protective film with microstructure have a wider range of applicability.

[0039] In the protective film with a microstructure, the angles included in the cross-sectional shape of the prism are designed to be rounded. At the microscopic level, the existence of the rounded angles changes the geometric properties of the prism surface, causing the prism to exhibit mechanical and optical behaviors different from traditional sharp edges when in contact with other objects. In practical applications, this rounded angle design can improve the performance of the protective film, and can bring into play its unique advantages during attachment, use, and removal, providing more comprehensive and reliable protection for the protected surface. After adopting the rounded angle design, the stress is more evenly distributed on the surface of the prism, avoiding the occurrence of stress concentration. When the prism with rounded angles comes into contact with the protected surface, it can better fit the microscopic unevenness of the surface. The protected surface usually has a certain degree of roughness. When the sharp-edged prism comes into contact with these microscopic unevenness, gaps or incomplete fit may occur, resulting in air residue or poor contact between the adhesive layer and the protected surface. The rounded corner design can make it easier for the prism to fill these microscopic gaps, increase the contact area between the adhesive layer and the protected surface, and improve the tightness of the fit. During the attachment process, the rounded corner can also reduce the friction between the prism and the protected surface, making it easier for the protective film to slide and adjust its position, improving the efficiency and accuracy of attachment.

[0040] The microstructured protective film further adds an antistatic layer in the structural design. The antistatic layer is precisely arranged on the side of the substrate layer 100 opposite to the pressure-sensitive adhesive layer 200, that is, at the outermost position of the protective film. As the interface between the protective film and the external environment, the antistatic layer plays a key protective role. It can effectively deal with the static electricity problems caused by friction, contact, etc. during the production, storage, transportation and use of the protective film, provide all-round and multi-level protection for the protected products, and ensure that the products are protected from the potential harm caused by static electricity in every link.

[0041] Specifically, it also includes a release film 300. As an important component of the protective film, the release film 300 can effectively prevent 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 can protect the pressure-sensitive adhesive layer 200 from dust, impurities, etc., and maintain the cleanliness of the pressure-sensitive adhesive; and when in use, it can be easily peeled off from the protective film so that the protective film can be smoothly attached to the protected surface. The thickness of the release film 300 is in the range of 30-80μm. This thickness design makes the release film 300 have a certain strength and can be easily peeled off from the protective film.

[0042] The present 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, applying the liquid pressure-sensitive adhesive on a transfer substrate, wherein the transfer substrate includes a groove corresponding to the prismatic microstructure, applying the pressure-sensitive adhesive to the surface of the substrate by transfer, irradiating light, and curing the pressure-sensitive adhesive applied to the surface of the substrate by photocuring to form a pressure-sensitive adhesive layer 200 including a prismatic microstructure.

[0043] First, prepare the substrate and the photocurable pressure-sensitive adhesive. As the supporting basis of the protective film, the material and performance of the substrate directly affect the overall quality and use effect of the protective film, and it needs to be strictly screened according to the specific application scenario. The photocurable pressure-sensitive adhesive has the characteristics of rapid curing and excellent adhesion performance. It is a key material for realizing the bonding function between the protective film and the protected surface. Then, the liquid pressure-sensitive adhesive is evenly coated on the transfer substrate, which contains grooves corresponding to the prism microstructure. The accuracy 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 coating amount and uniformity of the liquid pressure-sensitive adhesive need to be precisely controlled to ensure that the pressure-sensitive adhesive can fully fill the grooves of the transfer substrate, laying the foundation for the subsequent transfer process.

[0044] Then, the pressure-sensitive adhesive is accurately coated on the surface of the substrate by transfer printing. The transfer process requires the use of professional equipment and precise process parameter control to ensure that the pressure-sensitive adhesive can be completely transferred from the transfer substrate to the surface of the substrate and maintain the shape and accuracy of the prism microstructure. During the transfer process, care should be taken to avoid defects such as bubbles and wrinkles in the pressure-sensitive adhesive to ensure the quality of the pressure-sensitive adhesive layer 200. Afterwards, the pressure-sensitive adhesive coated on the surface of the substrate is subjected to light treatment. By selecting a suitable light source and light parameters, such as light intensity and light time, the pressure-sensitive adhesive undergoes a chemical reaction under the action of light, and is rapidly cured to form a pressure-sensitive adhesive layer 200 with a certain strength and adhesion performance. The light process needs to be carried out under specific environmental conditions to avoid the influence of external factors on the curing effect. A pressure-sensitive adhesive layer 200 including a prism microstructure is formed. The pressure-sensitive adhesive layer 200 not only has the adhesion function of ordinary pressure-sensitive adhesives, but also has special optical or physical properties due to its unique prism microstructure, such as anti-reflection, anti-reflection, light guiding, etc., which can provide more comprehensive and efficient protection for the protected surface.

[0045] By using the grooves corresponding to the prismatic microstructures in the transfer substrate, the shape and size of the prismatic microstructure can be copied to the pressure-sensitive adhesive layer 200, which can ensure that the prismatic microstructure on the pressure-sensitive adhesive layer 200 has consistency and accuracy, and meet the requirements of microstructure accuracy in different application scenarios. For example, in the field of optics, precise prismatic microstructures can improve the optical properties of optical components and reduce light loss and interference. By adjusting the shape and size of the grooves of the transfer substrate, the parameters of the prismatic microstructure on the pressure-sensitive adhesive layer 200, such as the height, angle, and spacing of the prism, can be easily controlled. This structural controllability enables the production method to customize prismatic microstructures with specific properties according to different needs, thereby improving the versatility and applicability of the protective film.

[0046] The use of the light-curing pressure-sensitive adhesive enables the pressure-sensitive adhesive layer 200 to cure in a short time, which can greatly shorten the production cycle and improve production efficiency. In the process of large-scale production, this fast curing characteristic can reduce production costs. The pressure-sensitive adhesive is applied to the surface of the substrate by transfer printing, which can ensure that the thickness and adhesion of the pressure-sensitive adhesive layer 200 are evenly distributed. The uniform pressure-sensitive adhesive layer 200 can provide more reliable adhesion performance, so that the protective film can be firmly attached to the protected surface, and it is not easy to fall off or have poor local adhesion.

[0047] Specifically, the depth of the groove is in the range of 0.3-1 times the width of the groove. The ratio of the groove depth to the width has a crucial influence on the subsequent filling and transfer of the pressure-sensitive adhesive and the performance of the prismatic microstructure formed in the end. The appropriate depth-width ratio can ensure that the pressure-sensitive adhesive is fully filled in the groove and completely and accurately copied to the surface of the substrate during the transfer process, thereby forming a prismatic microstructure pressure-sensitive adhesive layer 200 with high quality and excellent performance.

[0048] In the method for making a protective film with a microstructure, the transfer substrate used is a light-transmitting substrate. The light-transmitting substrate has excellent optical transmittance. It can use its own characteristics to allow light to pass through the substrate and irradiate the pressure-sensitive adhesive while the transfer step is being carried out, thereby realizing the light curing of the pressure-sensitive adhesive. During the transfer process, as the pressure-sensitive adhesive is transferred from the transfer substrate to the surface of the substrate, the light acts accurately on the pressure-sensitive adhesive, so that it completes the curing reaction in a short time. This simultaneous transfer and light curing operation not only improves production efficiency, but also ensures the uniformity and consistency of the curing effect of the pressure-sensitive adhesive. The general pressure-sensitive adhesive curing method is usually to perform a separate light curing step after the transfer is completed, which requires the transferred substrate to be transferred to a special light curing equipment, which increases the production links and time costs. The use of a light-transmitting substrate for light curing at the same time as the transfer combines the two originally independent steps into a continuous process, greatly shortening the production cycle. For example, in the large-scale production of protective films with microstructures, this synchronous operation can significantly increase the output per unit time, reduce production costs, and improve the economic benefits of the enterprise. Specific embodiments Some specific implementation methods will be further introduced below to further explain the technical solution of this application in detail.

[0050] Embodiment 1 A microstructure protective film is prepared, and a pressure-sensitive adhesive is applied to a 50μm PET surface by microstructure transfer and light-cured to form a prism strip microstructure pressure-sensitive adhesive coating, wherein the pressure-sensitive adhesive is one of polyurethane, acrylic, silicone, and rubber, preferably polyurethane. The prism structure is an isosceles triangle with a base width of 50μm and a prism height of 25μm.

[0051] Embodiment 2 A microstructure protective film is prepared, and a pressure-sensitive adhesive is applied to a 50μm PET surface by microstructure transfer and light-cured to form a prism strip microstructure pressure-sensitive adhesive coating, wherein the pressure-sensitive adhesive is one of polyurethane, acrylic, silicone, and rubber, preferably polyurethane. The prism structure is an isosceles triangle with a base width of 50μm and a prism height of 10μm.

[0052] Embodiment 3 A microstructure protective film is prepared, and a pressure-sensitive adhesive is applied to a 50μm PET surface by microstructure transfer and light-cured to form a prism strip microstructure pressure-sensitive adhesive coating, wherein the pressure-sensitive adhesive is one of polyurethane, acrylic, silicone, and rubber, preferably polyurethane. The prism structure is an isosceles triangle with a base width of 50μm and a prism height of 60μm.

[0053] Comparative Example 1 The comparative example is a general exhaust film, which does not have a prism structure. Compared with general exhaust protective films, microstructure protective films have lower peeling force. And microstructure protective films can have direction-selective peeling force. In addition, microstructure protective films exhibit special permeability functions, which can have both surface protection function and rapid penetration function on the protected surface. When the microstructure height is less than 0.3 times the width, it affects the penetration speed. When the microstructure height is greater than 1 times the width, the attachment effect is too poor and there is a risk of natural falling off.

[0054] As can be seen from the foregoing, the present application provides a protective film with a microstructure, which is composed of a substrate layer and a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layer is arranged on one side of the substrate layer, and its surface relative to the substrate layer has a unique prismatic microstructure. The prismatic microstructure is composed of a plurality of prisms arranged closely together. The arrangement directions of all prisms are consistent, and the cross-sectional shape can be a trapezoid, an isosceles triangle or an arc. The presence of the prismatic microstructure provides more exhaust channels for air. When the protective film is attached to the protected surface, the air can be quickly discharged along the gaps between the prisms, effectively avoiding the generation of bubbles. For example, when attaching a large glass plate, a traditional flat protective film may form bubbles because the air cannot be discharged in time, affecting the protective effect. The protective film with a prismatic microstructure of the present application can ensure smooth attachment without bubbles.

[0055] The prisms are arranged in the same direction, which makes the air have a certain directionality when it is discharged, further speeding up the exhaust speed and reducing the resistance during the air discharge process. The special shape and size design of the prism microstructure changes the contact mode between the pressure-sensitive adhesive layer and the protected surface. When the protective film is torn off, the gaps between the prisms can reduce the contact area between the adhesive layer and the protected surface, thereby reducing the adhesion and reducing the generation of residual adhesive.

[0056] The bottom width and height of the prism body make the pressure-sensitive adhesive layer have sufficient adhesion while maintaining good detachment performance when peeled off, achieving a balance between adhesion and detachment performance. Prisms with various cross-sectional shapes (trapezoidal, isosceles triangle or arc shape) can adapt to different protected surfaces and attachment requirements. For example, a trapezoidal prism body may be more suitable for objects with rough surfaces, while an arc-shaped prism body is more suitable for occasions that require high-precision attachment. The setting of the bottom width and height range of the prism body also takes into account the size and performance requirements of different products, so that the protective film can be widely used in various products. When the protective film needs to be torn off, since the arrangement direction of the prism microstructure is the same as the tearing direction, a synergistic effect can be formed, making the tearing process smoother and more efficient. This arrangement not only reduces the tearing resistance, but also reduces the damage to the protected surface, improving production efficiency and product quality.

[0057] The present application also provides a method for making a protective film with a microstructure, which uses a light-transmitting substrate for transfer printing, and simultaneously irradiates light through the light-transmitting substrate to photocuring the pressure-sensitive adhesive. This simultaneous transfer and photocuring operation not only improves production efficiency, but also ensures the uniformity and consistency of the curing effect of the pressure-sensitive adhesive. By using the grooves corresponding to the prism microstructure in the transfer substrate, the shape and size of the prism microstructure can be accurately copied to the pressure-sensitive adhesive layer, meeting the requirements for microstructure accuracy in different application scenarios.

[0058] The above is only a specific implementation of the present application, and any other improvements made based on the concept of the present application are deemed to be within the protection scope of the present application.

Claims

1. A protective film with a microstructure, characterized in that: It comprises a substrate layer and a pressure-sensitive adhesive layer, wherein a side of the pressure-sensitive adhesive layer opposite to the substrate layer comprises a prismatic microstructure; The prismatic microstructure comprises a plurality of prism bodies arranged together, the prism bodies are arranged in the same direction, and the cross-sectional shape of the prism body is a trapezoid, an isosceles triangle or an arc; 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 of the bottom width of the prism body.

2. The protective film with microstructure according to claim 1, characterized in that: The thickness of the substrate layer is in the range of 20-500 μm.

3. The protective film with microstructure according to claim 1, characterized in that: The arrangement direction of the prism microstructure is the same as the tearing direction of the protective film.

4. The protective film with microstructure according to claim 1, characterized in that: The material of the substrate layer is selected from one or more of PC, PET, PI, PP, PE, TAC or SRF; 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.

5. The protective film with microstructure according to claim 1, characterized in that: The angles included in the cross-sectional shape of the prism body are all arc angles.

6. The protective film with microstructure according to claim 1, characterized in that: It also includes an antistatic layer, which is arranged on a side of the substrate layer opposite to the pressure-sensitive adhesive layer.

7. The protective film with microstructure according to claim 1, characterized in that: Also includes a release film.

8. A method for preparing a protective film having a microstructure, characterized in that: The steps include: Provide substrate and light-curing pressure-sensitive adhesive; Applying a liquid pressure-sensitive adhesive on a transfer substrate, wherein the transfer substrate includes grooves corresponding to the prism microstructures; The pressure-sensitive adhesive is applied to the surface of the substrate by transfer printing; The pressure-sensitive adhesive coated on the surface of the substrate is cured by light irradiation to form a pressure-sensitive adhesive layer including a prism microstructure.

9. The method for manufacturing a protective film with a microstructure according to claim 8, characterized in that: The depth of the groove is in the range of 0.3-1 times the width of the groove.

10. The method for manufacturing a protective film with a microstructure according to claim 8, characterized in that: The transfer substrate is a light-transmitting substrate, and light is irradiated through the light-transmitting substrate to photo-cure the pressure-sensitive adhesive during transfer.

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