A grid release film, its preparation method and tape

Abstract

The present disclosure provides a grid release film, a preparation method thereof, and a tape. The present disclosure relates to the technical field of release films. A grid release film includes a substrate layer and a resin grid layer which are sequentially stacked from bottom to top, and the resin grid layer forms a grid structure on a side facing away from the substrate layer; the grid structure is composed of a plurality of hexagonal grids connected to each other, and the groove ridges formed between adjacent hexagonal grids meet at the vertex positions of the hexagonal grids to form a node structure, and the diameter of the circumscribed circle of the node structure is 15 to 30 μm. When the size of the node structure on the grid structure of the grid release film of the present disclosure is limited within the range of 15 to 30 μm, it can cooperate with the width and depth of the groove ridges, so that the bubbles in the grid-shaped exhaust grooves formed on the pressure-sensitive adhesive can be quickly discharged, and the exhaust grooves can also disappear within a preset time.

Description

Technical Field

[0001] The present disclosure relates to the technical field of release films, and in particular to a grid release film, a preparation method thereof, and a tape. Background Art

[0002] The preparation methods of the existing grid release films in the market generally include melting PE particles first, and then coating the film on the surface of the substrate, embossing, and cooling to form a grid layer on the surface of the substrate, and then coating a release agent on the surface of the grid layer to form a release layer on the grid layer. Another example is a embossed release film disclosed in Chinese Patent Application (CN106273956A), which includes a substrate layer, a coated film layer, and a release layer; the coated film layer is provided on the substrate layer, and the surface of the coated film layer is formed with textures; the release layer is provided on the coated film layer and is matched and adhered to the textures; the coated film layer is a polyethylene layer or a polypropylene layer.

[0003] However, the grid layer / coated film layer prepared from PE material (the highest heat resistance is 90 ° C) is not resistant to high temperature. Therefore, when the grid release film and the pressure-sensitive adhesive are prepared to form an application product (such as a tape), since the general drying temperature of the adhesive is above 100 ° C, when the adhesive is coated on the release layer and dried, the grid embossing on the surface of the release film will be deformed, resulting in uneven depths of the grid-shaped exhaust grooves formed on the pressure-sensitive adhesive and unstable exhaust effect.

[0004] In addition, we also found that the grid layer structure of the grid release film is generally a quadrilateral grid structure, and the corresponding exhaust grooves formed on the pressure-sensitive adhesive are quadrilateral exhaust grooves. However, we found that when the pressure-sensitive adhesive is actually adhered to the surface of the object to be pasted, the bubbles in the exhaust grooves cannot be eliminated and the exhaust grooves cannot disappear within the preset time, that is, the exhaust effect and the disappearable effect of the exhaust grooves are not good, which not only affects the production rhythm, but also affects the appearance and performance of the object to be pasted, and also requires additional equipment to eliminate the bubbles, which undoubtedly increases the production cost and reduces the production efficiency. Summary of the Invention

[0005] The present disclosure provides a grid release film, a preparation method thereof, and a tape to at least solve one of the technical problems existing in the prior art.

[0006] According to a first aspect of the present disclosure, the present invention provides a grid release film, including a substrate layer and a resin grid layer which are sequentially stacked from bottom to top, and the resin grid layer forms a grid structure on a side facing away from the substrate layer; the grid structure is composed of a plurality of hexagonal grids connected to each other, and the pressure groove ridges formed between adjacent hexagonal grids meet at the vertex positions of the hexagonal grids to form a node structure, and the diameter of the circumscribed circle of the node structure is 15-30 μm.

[0007] In an implementable embodiment, the depth of the grooved rib is 5 - 10 μm, and the width of the grooved rib is 19 - 25 μm.

[0008] In an implementable embodiment, the resin mesh layer is configured to be deformable at least at 100 °C, and the resin mesh layer is formed by photocuring of UV resin liquid.

[0009] In an implementable embodiment, the UV resin liquid comprises raw materials in the following parts by weight: 100 parts of UV glue, 3 - 12 parts of UV crosslinking agent, and 3 - 4 parts of UV initiator; wherein, the UV crosslinking agent is one or a mixture of more than one of a difunctional UV crosslinking agent, a trifunctional UV crosslinking agent, and a tetrafunctional UV crosslinking agent.

[0010] In an implementable embodiment, the difunctional UV crosslinking agent is one or a mixture of more than one of polyethylene glycol 400 diacrylate, 1,6 - hexanediol diacrylate, and polyurethane - modified diallyl oligomer;

[0011] The trifunctional UV crosslinking agent is one or a mixture of more than one of trimethylolpropane tris[3 - (2 - methylaziridinyl)propionate], trimethylolpropane triacrylate, and pentaerythritol triacrylate;

[0012] The tetrafunctional UV crosslinking agent is one or a mixture of more than one of pentaerythritol tetraallyl ether and tetrafunctional polyester acrylate;

[0013] The UV initiator is one or a mixture of more than one of 1 - hydroxycyclohexyl phenyl ketone, diphenyl - (2,4,6 - trimethylbenzoyl)phosphine oxide, 2 - isopropylthioxanthone, and isopropyl thioxanthone.

[0014] In an implementable embodiment, it further includes a release layer, and the release layer is laminated on the grid structure of the resin mesh layer.

[0015] According to the second aspect of the present disclosure, the present invention provides a method for preparing a grid release film, which is applied to the grid release film, and the preparation method includes:

[0016] Transfer - coat the UV resin liquid onto the surface of the substrate layer through an anilox roll, and then perform UV pre - curing, so as to preliminarily form a resin mesh layer with a grid structure on the surface of the substrate layer, and the UV exposure amount during the UV pre - curing is 500 - 2000 mj / cm 2 ;

[0017] Perform UV secondary curing and molding on the substrate layer with the resin mesh layer formed on its surface; wherein the UV exposure amount during the UV secondary curing is 500 - 2000 mj / cm 2 。

[0018] In one possible implementation, the UV resin liquid includes raw materials in the following parts by weight: 100 parts of UV glue, 3 to 12 parts of UV crosslinking agent, and 3 to 4 parts of UV initiator; wherein, the UV crosslinking agent is one or a mixture of a bifunctional UV crosslinking agent, a trifunctional UV crosslinking agent, and a tetrafunctional UV crosslinking agent.

[0019] In one possible implementation, the preparation method further includes: coating a release agent on the surface of the grid structure of the resin grid layer to form a release layer.

[0020] According to the third aspect of the present disclosure, there is provided a tape including the grid release film or the grid release film prepared by the method.

[0021] Compared with the prior art, the advantages of the present application are as follows: 1) When the size of the node structure on the grid structure of the grid release film of the present application is limited within the range of 15 to 30 μm, it can cooperate with the width and depth of the grooved ridges, so that the bubbles in the grid-shaped exhaust grooves formed on the pressure-sensitive adhesive can be quickly discharged, and the exhaust grooves can also disappear within a preset time.

[0022] 2) The resin grid layer of the present application is formed by photocuring of the UV resin liquid, so that the resin grid layer is heat-resistant (the temperature remains unchanged at 90 to 150 °C, and it can even remain unchanged above 150 °C). Therefore, when the adhesive is coated on the grid release film and dried to form a pressure-sensitive adhesive layer, it can ensure that the entire grid release film does not deform, the grid structure does not deform, thereby ensuring that the depth of the exhaust grooves formed on the surface of the pressure-sensitive adhesive is consistent, and ensuring the exhaust stability and disappearability of the exhaust grooves.

[0023] 3) The present application adopts a coating process, which has more advantages in controlling the size and appearance than the existing conventional film coating process. The UV curing and embossing are faster and more thorough, and the depth and width data of the formed grid structure are more stable.

[0024] It should be understood that the content described in this part is not intended to identify the key or important features of the embodiments of the present disclosure, nor is it used to limit the scope of the present disclosure. Other features of the present disclosure will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] By referring to the accompanying drawings and reading the following detailed description, the above and other objects, features, and advantages of the exemplary embodiments of the present disclosure will become easily understood. In the drawings, several embodiments of the present disclosure are shown in an exemplary rather than restrictive manner, wherein:

[0026] In the drawings, the same or corresponding reference numerals represent the same or corresponding parts.

[0027] Figure 1Shows a schematic structural diagram of the grid release film according to an embodiment of the present disclosure;

[0028] Figure 2 Shows a top view of the grid release film according to an embodiment of the present disclosure under a microscope;

[0029] Figure 3 Shows a schematic diagram of a node structure formed by the intersection of the groove ridges in the grid structure of the grid release film according to an embodiment of the present disclosure;

[0030] Figure 4 Shows a schematic diagram when the grid structure of the grid release film according to an embodiment of the present disclosure and the current conventional quadrilateral grid structure are arranged;

[0031] Figure 5 Shows the node structure formed by the intersection of the groove ridges in the first case according to an embodiment of the present disclosure;

[0032] Figure 6 Shows the node structure formed by the intersection of the groove ridges in the second case according to an embodiment of the present disclosure;

[0033] Figure 7 Shows the node structure formed by the intersection of the groove ridges in the third case according to an embodiment of the present disclosure. Detailed implementation manners

[0034] To make the objectives, features, and advantages of the present disclosure more obvious and understandable, the technical solutions in the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only a part of the embodiments of the present disclosure, rather than all the embodiments. Based on the embodiments in the present disclosure, all other embodiments obtained by those skilled in the art without creative efforts shall fall within the protection scope of the present disclosure.

[0035] Since the grid release film in the current market cannot directly coat the pressure-sensitive adhesive on the release layer under high-temperature conditions, when the adhesive is coated, the surface of the grid release film will be deformed, which will further cause the grid-shaped exhaust grooves formed on the surface of the pressure-sensitive adhesive to have inconsistent depths and unstable exhaust effects. Moreover, after the structure and size of the grid structure of the current grid release film are transferred to the pressure-sensitive adhesive, when the pressure-sensitive adhesive is pasted on the surface of the item to be adhered, the bubbles generated in the exhaust grooves cannot be eliminated, and the exhaust grooves cannot disappear within the preset time, which affects the appearance and performance of the adhered item.

[0036] Based on the above problems, the applicant has conducted creative research and experiments to improve the preparation materials, preparation process of the grid release film, and the grid structure on the grid release film. This not only solves the problem of stably coating the adhesive on the grid release film under high-temperature conditions, but also solves the problem that when the grid release film is specifically compounded with the pressure-sensitive adhesive to prepare an application product (such as a tape), the depth of the grid-shaped exhaust grooves on the pressure-sensitive adhesive can be made consistent. When the pressure-sensitive adhesive is adhered to an object to be pasted (such as mobile phones and other electronic products), the air bubbles can be quickly discharged, and the exhaust grooves on the surface of the pressure-sensitive adhesive can disappear within a short time without affecting the appearance and performance of the object to be pasted.

[0037] Based on this, according to the first aspect of the present invention, the present application first provides a grid release film.

[0038] As Figure 1-3 shown, a grid release film includes a substrate layer 1 and a resin grid layer 2 stacked in sequence from bottom to top. A grid structure 3 is formed on the side of the resin grid layer 2 facing away from the substrate layer 1; the grid structure 3 is composed of a plurality of uniformly arranged hexagonal grids 31 connected to each other. A groove rib 32 is formed between adjacent hexagonal grids 31. The groove ribs 32 between adjacent hexagonal grids meet at the top corner positions of the hexagonal grids to form a node structure 33. The node structure 33 is generally triangular in shape, and the diameter of the circumscribed circle of the node structure is 15 - 30 μm. Exemplarily, the diameter of the circumscribed circle of the node structure can be 15 μm, 20 μm, 25 μm, 30 μm. For example, in the present application, the so-called "circumscribed circle of the node structure" is the circumscribed circle of the virtual triangle formed by the connection lines between the top corners of the adjacent hexagons at the intersection position. That is to say, the so-called "circumscribed circle of the node structure" is the circumscribed circle of the virtual triangle formed by the wide sides (in the width direction) of the adjacent groove ribs at the intersection position.

[0039] For example, as Figure 3 shown, the hexagonal grid in this embodiment can be a regular hexagon, and the side length of the hexagonal grid is 160 - 180 um.

[0040] For example, as Figure 1 shown, in this embodiment, the resin grid layer 2 includes a resin plane layer 21 and a grid structure 3. The resin plane layer 21 is disposed on the side close to the substrate layer 1, and the grid structure 3 is disposed on the side of the resin plane layer 21 facing away from the substrate layer 1, and the grid structure 3 protrudes from the resin plane layer 21.

[0041] As Figure 1-2As shown in the figure, in the present application, the side of the resin grid layer 2 facing away from the substrate layer is a grid-shaped grid structure. The grid structure 3 is composed of a plurality of uniformly arranged hexagonal grids 31 connected to each other. Substantially, these hexagonal grids 31 are arranged and connected in the shape order of a hexagon by the groove ridges 32, so that adjacent hexagonal grids 31 share a groove ridge 32. The groove ridges 32 between adjacent hexagonal grids meet at the apex positions of the hexagon to form a node structure 33, and these groove ridges 32 are connected to each other through the node structure. Thus, when the pressure-sensitive adhesive is laminated on the surface of the grid release film, these groove ridges 32 on the grid structure 3 can form corresponding grid-shaped hexagonal exhaust grooves on the surface of the pressure-sensitive adhesive. These exhaust grooves also meet at the apex positions of the hexagon to form exhaust nodes (when the node structure of the grid release film is transferred to the pressure-sensitive adhesive layer, exhaust nodes will be formed on the surface of the pressure-sensitive adhesive layer). After the grid release film is peeled off from the pressure-sensitive adhesive, the overall pressure-sensitive adhesive has grid-shaped exhaust grooves, so that when the pressure-sensitive adhesive is attached to the item to be pasted, the air bubbles in the exhaust grooves can be quickly discharged and the exhaust grooves can disappear within a preset time.

[0042] In the present application, the grid structure 3 on the grid release film is composed of hexagonal grids 31 connected to each other as units. We found that compared with the conventional quadrilateral grid structure on the current release film, under the same conditions, the more sides the polygon grid has, the more exhaust nodes the exhaust grooves formed on the surface of the pressure-sensitive adhesive have, and the exhaust effect shows a positive correlation. Since the grid structure 3 is formed by transferring and coating the resin liquid onto the surface of the substrate layer using a gravure roll, it is necessary to engrave a pattern corresponding to the grid structure on the gravure roll. Considering the difficulty of implementing the pattern on the gravure roll, hexagonal grids are preferably used.

[0043] When the pressure-sensitive adhesive is attached to the item to be pasted, most of the air bubbles in the exhaust grooves gather at the exhaust node positions. This causes the air bubbles in the exhaust grooves formed on the surface of the pressure-sensitive adhesive after the grid release film on the market is attached to the pressure-sensitive adhesive to be unable to be discharged and the exhaust grooves cannot disappear within a preset time. Through a large number of research experiments, it is found that when the size of the node structure (i.e., the diameter of the circumscribed circle of the node structure) on the grid structure of the grid release film is limited within the range of 15 - 30 μm, it can cooperate with the width and depth of the groove ridges to enable the air bubbles in the exhaust grooves on the pressure-sensitive adhesive to be quickly discharged, and the exhaust grooves can also disappear within a preset time.

[0044] In this embodiment, when the grid structure 3 is composed of a plurality of uniformly arranged hexagonal grids 31 connected to each other; correspondingly, the exhaust grooves formed on the surface of the pressure-sensitive adhesive are hexagonal exhaust grooves, and these hexagonal exhaust grooves are interconnected through exhaust nodes to form a grid shape. Under the same conditions, the number of hexagonal exhaust grooves and exhaust nodes is more than that of the current conventional quadrilateral exhaust grooves. The more the number of exhaust grooves and exhaust nodes, the better the exhaust effect. Therefore, the hexagonal exhaust grooves are superior to the quadrilateral exhaust grooves in terms of exhaust effect.

[0045] For example, when the grid structure on the grid release film is transferred to the pressure-sensitive adhesive, it corresponds to the shape of the formed exhaust grooves. Thus, as Figure 4 shown, in this embodiment, we take the grid structure 3 composed of the arrangement of hexagonal grids 31 as an example, and compare it with the grid structure composed of the arrangement of conventional quadrilateral grids on the current market. We analyze the hexagonal grid-shaped exhaust grooves and quadrilateral grid-shaped exhaust grooves formed by transferring them to the surface of the pressure-sensitive adhesive respectively. We select hexagonal exhaust grooves and quadrilateral exhaust grooves with the same conditions and the same area for arrangement, and the results show that the rule of increasing exhaust nodes is (the rule of the number and exhaust nodes of the quadrilateral exhaust grooves and hexagonal exhaust grooves shown in Table 1): 1) When the number of quadrilateral exhaust grooves increases to an odd number, one exhaust node is added. When the number of quadrilateral exhaust grooves increases to an even number, two exhaust nodes are added. 2) As long as the number of hexagonal exhaust grooves increases by one, the corresponding exhaust nodes will increase by two. Therefore, when selecting a polygon for the grid release film, the following two points need to be achieved: First, it can be densely arranged without blank areas, and the exhaust grooves form a continuous channel without breakpoints. Second, the number of exhaust grooves and exhaust nodes should be as many as possible. Therefore, the hexagonal exhaust grooves are the best choice that meets these two points. Correspondingly, on the grid release film, the hexagonal grid is the best choice for the polygon grid forming the grid structure.

[0046] Table 1 Rules of the number and exhaust nodes of the existing conventional quadrilateral exhaust grooves and the hexagonal exhaust grooves of this application

[0047]

[0048] Furthermore, as Figure 1 shown, the grid release film of this embodiment further includes a release layer 4, and the release layer 4 is laminated on the grid structure 3 of the resin grid layer. That is, the grid structure 3 is formed on the side of the resin grid layer 2 of the grid release film in contact with the release layer 4, and the release layer 4 is laminated on the grid structure 3.

[0049] When applying a pressure - sensitive adhesive on a mesh release film to further prepare an application product (such as a tape), a release layer is first provided on the resin mesh layer to ensure that the mesh release film can be peeled off from the pressure - sensitive adhesive. The thickness of the release layer 4 is generally 0.5 - 1μm. Compared with the mesh structure, the thickness of the release film can be ignored. Therefore, when the mesh release film composed of a substrate layer, a resin mesh layer, and a release layer is compounded with the pressure - sensitive adhesive, the mesh structure can be transferred to the pressure - sensitive adhesive, forming corresponding hexagonal exhaust grooves in a grid pattern on the surface of the pressure - sensitive adhesive. The depth, width, and exhaust nodes of the exhaust grooves on the pressure - sensitive adhesive are equivalent to the depth, width, and node structure dimensions of the pressing grooves and ridges of the mesh structure.

[0050] For example, the material of the substrate layer is one of PET, PI, BOPP, paper, and PEEK. The material of the release layer is solvent - containing silicone oil or solvent - free silicone oil. The material of the resin mesh layer is a high - temperature - resistant resin.

[0051] For example, the thickness of the substrate layer is 25 - 188μm. The thickness of the resin mesh layer is 15 - 100μm.

[0052] In some embodiments, the depth of the pressing groove and ridge 32 (i.e., the depth of the mesh structure 3) is 5 - 10μm, and the width of the pressing groove and ridge is 19 - 25μm. Exemplarily, the depth of the pressing groove and ridge can be 5μm, 8μm, 10μm. The width of the pressing groove and ridge can be 19μm, 22μm, 25μm. We found through research that the exhaustibility and disappearability of the exhaust grooves on the surface of the pressure - sensitive adhesive are a set of paradoxes and are mutually contradictory. If we want to ensure the exhaustibility of the exhaust grooves, we need to increase the physical dimensions of the exhaust grooves (such as the depth and width of the exhaust grooves), but the increase in the physical dimensions of the exhaust grooves makes the difficulty of the disappearability of the exhaust grooves increase exponentially, which means that the disappearability of the exhaust grooves cannot be achieved. And if we want to ensure the disappearability of the exhaust grooves, we need to appropriately reduce the physical dimensions of the exhaust grooves, such as reducing the width and / or depth of the exhaust grooves, but the bubbles in the exhaust grooves cannot be discharged smoothly. Therefore, it is necessary to find a balance between exhaustibility and disappearability to ensure that these two properties can be achieved simultaneously. In addition, since most of the bubbles in the exhaust grooves gather at the exhaust node positions and are difficult to discharge, we found through a large number of orthogonal tests that on the premise that the diameter of the circumscribed circle of the node structure of the mesh release film is 15 - 30μm, when the depth of the pressing groove and ridge on the mesh release film is 5 - 10μm and the width of the pressing groove and ridge is 19 - 25μm, the exhaust grooves transferred to the surface of the pressure - sensitive adhesive can enable the bubbles in both the exhaust groove channels and the exhaust nodes where the ends of the exhaust grooves meet to be quickly discharged while the exhaust grooves also disappear within a preset time.

[0053] For example, as Figure 3As shown, the grooved ridges 32 between adjacent hexagonal grids 31 converge at the apex positions of the hexagons to form a node structure 33. In this application, the node structure 33 formed by the convergence of adjacent grooved ridges 32 can be arranged in any of the following ways, including but not limited to: As Figure 3 shown, the grooved ridges 32 between three adjacent hexagonal grids 31 converge at one of the apex positions of the hexagonal grid to form a node structure 33, and the shape of this node structure is triangular. As Figure 5 shown. When the size of the node structure is slightly smaller, near the convergence point, the two side edges of the grooved ridge 32 gradually contract inward, and the shapes of the two side edges are generally convex arc shapes, causing the width of the grooved ridge to gradually decrease, so that three adjacent grooved ridges 32 converge to form a node structure 33.

[0054] Or, it can also be, as Figure 6 shown, when the size of the node structure 33 is slightly larger, near the convergence point, the two side edges of the grooved ridge 32 gradually expand outward, and the shapes of the two side edges are generally concave arc shapes, causing the width of the grooved ridge 32 to gradually increase, so that three adjacent grooved ridges 32 converge to form a node structure.

[0055] Or, it can also be, as Figure 7 shown, the width of the grooved ridge 32 does not change. Adjacent grooved ridges 32 converge to form a node structure 33.

[0056] In summary, near the position of the node structure 33, a transition section is formed between the grooved ridge 32 and the node structure 33. Towards the direction of approaching the node structure 33, the width of this transition section gradually decreases, or it can also be that the width of the transition section gradually increases, or it can also be that the width of the transition section remains unchanged.

[0057] The arrangement of the node structures formed by the convergence of the above grooved ridges needs to be adjusted accordingly according to the width of the grooved ridges and the size of the node structures.

[0058] And since the resin grid layer is formed by embossing and transferring with a gravure roll, corresponding texture patterns can be engraved on the surface of the gravure roll in advance, and the structure and shape of this texture pattern correspond to the grid structure.

[0059] In some embodiments, the resin grid layer 2 is configured to be able to remain unchanged in shape at a temperature of at least 100°C, and the resin grid layer is formed by photocuring of a UV resin solution.

[0060] Further, the UV resin liquid comprises raw materials in the following parts by weight: 100 parts of UV glue, 3 - 12 parts of UV crosslinking agent, and 3 - 4 parts of UV initiator; wherein, the UV crosslinking agent is one or a mixture of more than one of a difunctional UV crosslinking agent, a trifunctional UV crosslinking agent, and a tetrafunctional UV crosslinking agent. The addition amount of the UV initiator is 3% - 4% of the addition amount of the UV glue.

[0061] For example, epoxy - based UV glue can be used as the UV glue, and the selectable models include but are not limited to: Loctite EA3335, TSBD2640, Letuo 3523.

[0062] The UV initiator can initiate a polymerization reaction when the material is irradiated with ultraviolet light. Exemplarily, the UV initiator is one or a mixture of more than one of: 1 - hydroxycyclohexyl phenyl ketone (PI - 184), diphenyl - (2,4,6 - trimethylbenzoyl) phosphine oxide (TPO), 2 - isopropyl thioxanthone, isopropyl thioxanthone (ITX105).

[0063] The difunctional UV crosslinking agent includes but is not limited to: polyethylene glycol 400 diacrylate (PEG400DA), 1,6 - hexanediol diacrylate (HDDA, also known as "1,6 - hexanediol diacrylate"), polyurethane - modified diallyl oligomer (DOUBLEMER® 5222).

[0064] The trifunctional UV crosslinking agent includes but is not limited to: trimethylolpropane tris[3 - (2 - methylaziridinyl) propionate] (TTMAP), trimethylolpropane triacrylate (TMPTA), pentaerythritol triacrylate (PETA).

[0065] The tetrafunctional UV crosslinking agent includes but is not limited to:

[0066] pentaerythritol tetraallyl ether, tetrafunctional polyester acrylate (ETERCURE 6325 - 100).

[0067] In this embodiment, the resin grid layer is formed by photocuring the UV resin liquid, so that the resin grid layer is heat - resistant (the temperature remains unchanged at 90 - 150 °C without deformation, and can even remain unchanged above 150 °C). Therefore, when the adhesive is coated on the grid release film and dried to form a pressure - sensitive adhesive, the entire grid release film can be ensured not to deform, the grid structure can be ensured not to deform, so as to ensure that the depth of the exhaust grooves formed on the surface of the pressure - sensitive adhesive is consistent, and the exhaust stability and disappearability of the exhaust grooves are ensured.

[0068] According to a second aspect of the present disclosure, the present invention further provides a method for preparing a grid release film. The preparation method includes drip coating - embossing - primary UV curing - secondary UV curing - forming to obtain the grid release film. The grid release film includes a substrate layer, a resin grid layer, and a release layer that are sequentially stacked from bottom to top. The resin grid layer forms a grid structure on the side in contact with the release layer.

[0069] The specific preparation method of the grid release film includes:

[0070] Step 1): Transfer and coat the UV resin solution onto the surface of the substrate layer through an anilox roll, and then perform primary UV curing, thereby initially forming a resin grid layer with a grid structure on the surface of the substrate layer. The UV exposure amount during the primary UV curing is 500 - 2000 mj / cm 2 ;

[0071] Step 2): Perform secondary UV curing and forming on the substrate layer with the resin grid layer formed on its surface; wherein the UV exposure amount during the secondary UV curing is 500 - 2000 mj / cm 2 ;

[0072] Step 3): Coat a release agent on the grid structure surface of the resin grid layer to form a release layer.

[0073] In this embodiment, the UV resin solution includes the following raw materials in parts by weight: 100 parts of UV glue, 3 - 12 parts of UV crosslinking agent, and 3 - 4 parts of UV initiator; wherein, the UV crosslinking agent is one or a mixture of a bifunctional UV crosslinking agent, a trifunctional UV crosslinking agent, and a tetrafunctional UV crosslinking agent.

[0074] In this embodiment, the UV resin solution is dropped onto the anilox roll, and the anilox roll transfers and coats the UV resin solution onto the surface of the substrate layer in an embossing form, and then performs primary UV curing. After the primary UV curing, a resin grid layer with a grid structure is formed on the surface of the substrate layer, and then further secondary UV curing is performed to form the resin grid layer on the surface of the substrate layer, further ensuring a firm connection between the resin grid layer and the substrate layer. It can be concluded from this that the materials of the resin grid layer and the grid structure formed on one side thereof are not only the same, but they are formed on the surface of the substrate layer in one step and integrally by UV curing. Then, a release agent (such as silicone oil) is coated on the grid structure to form a release layer.

[0075] In this embodiment, the coating process has more advantages in controlling the size and appearance than the existing conventional film coating process. The UV curing and embossing are faster and more thorough, and the depth and width data of the formed grid structure are more stable.

[0076] In a third aspect, the present disclosure also provides a tape, which includes the above-mentioned grid release film or the grid release film prepared by the above method. The tape with the grid release film of the present application also has the property that under high-temperature conditions, the grid release film can stably coat the pressure-sensitive adhesive to ensure the stability and non-deformation of the formed pressure-sensitive adhesive. Moreover, when the pressure-sensitive adhesive is attached to the item to be pasted, the exhaust grooves formed on the surface of the pressure-sensitive adhesive can quickly discharge air bubbles, and the exhaust grooves will disappear within a short time without affecting the appearance and performance of the item to be pasted.

[0077] Exemplarily, the tape includes a grid release film, a pressure-sensitive adhesive layer, a printed black film layer, a foam layer, an anti-adhesive coating, and a copper foil tape layer, which are laminated in sequence from bottom to top.

[0078] The following further elaborates on the present application with specific embodiments:

[0079] Example 1

[0080] As Figure 1 - Figure 3 shown, a grid release film includes a substrate layer 1, a resin grid layer 2, and a release layer 4, which are laminated in sequence from bottom to top. The resin grid layer 2 forms a grid structure 3 on the side facing away from the substrate layer 1 (that is, the resin grid layer 2 forms a grid structure 3 on the side in contact with the release layer 4);

[0081] The grid structure 3 is composed of a plurality of uniformly arranged hexagonal grids 31 connected to each other. There are pressure groove ridges 32 formed between adjacent hexagonal grids. The pressure groove ridges 32 between adjacent hexagonal grids meet at the vertex positions of the hexagonal grids to form a node structure 33. The shape of this node structure is triangular. The diameter of the circumscribed circle of the triangular node structure is 15 - 30 μm, the depth of the pressure groove ridge 32 is 5 - 10 μm, and the width of the pressure groove ridge 32 is 19 - 25 μm;

[0082] Among them, the material of the substrate layer is PET, and the resin grid layer is formed by photocuring of UV resin liquid. The UV resin liquid includes the following raw materials in parts by weight: 100 parts of UV glue, 10 parts of bifunctional UV crosslinking agent, and 3 parts of UV initiator. Among them, the bifunctional UV crosslinking agent is polyethylene glycol 400 diacrylate, and the UV initiator is 1-hydroxycyclohexyl phenyl ketone PI-184.

[0083] The specific preparation method of this grid release film includes:

[0084] Step 1): Transfer and coat the UV resin liquid onto the surface of the substrate layer through a gravure roll, and then perform UV pre-curing, so as to preliminarily form a resin grid layer with a grid structure on the surface of the substrate layer. The UV exposure amount during the UV pre-curing is 500 mj / cm 2 ;

[0085] Step 2): Subject the substrate layer with a resin mesh layer formed on its surface to UV secondary curing; the UV exposure dose during UV secondary curing is 500 mj / cm 2 ;

[0086] Step 3): Coat a release agent on the surface of the mesh structure of the resin mesh layer to form a release layer.

[0087] Example 2

[0088] This Example 2 is substantially the same as Example 1, except that the UV resin liquid includes the following raw materials in parts by weight: 100 parts of UV glue, 6 parts of difunctional UV crosslinking agent, 2 parts of trifunctional UV crosslinking agent, and 4 parts of UV initiator. Among them, the UV exposure dose during UV primary curing and UV secondary curing is both 1000 mj / cm 2 . The difunctional UV crosslinking agent is 1,6 - hexanediol diacrylate, the trifunctional UV crosslinking agent is trimethylolpropane triacrylate, and the UV initiator is diphenyl-(2,4,6 - trimethylbenzoyl) phosphine oxide TPO.

[0089] Example 3

[0090] This Example 3 is substantially the same as Example 1, except that the UV resin liquid includes the following raw materials in parts by weight: 100 parts of UV glue, 5 parts of trifunctional UV crosslinking agent, and 3 parts of UV initiator. Among them, the UV exposure dose during UV primary curing and UV secondary curing is both 1500 mj / cm 2 . The trifunctional UV crosslinking agent is pentaerythritol triacrylate, and the UV initiator is isopropyl thioxanthone ITX1105.

[0091] Example 4

[0092] This Example 4 is substantially the same as Example 1, except that the UV resin liquid includes the following raw materials in parts by weight: 100 parts of UV glue, 3 parts of tetrafunctional UV crosslinking agent, and 4 parts of UV initiator. Among them, the UV exposure dose during UV primary curing and UV secondary curing is both 1000 mj / cm 2 . The tetrafunctional UV crosslinking agent is pentaerythritol tetraallyl ether, and the UV initiator is 1 - hydroxycyclohexyl phenyl ketone PI - 184.

[0093] Example 5

[0094] This Example 5 is substantially the same as Example 1, except that the UV resin liquid includes the following raw materials in parts by weight: 100 parts of UV glue, 5 parts of difunctional UV crosslinking agent, 4 parts of trifunctional UV crosslinking agent, 3 parts of tetrafunctional UV crosslinking agent, and 3 parts of UV initiator. Among them, the UV exposure dose during UV primary curing and UV secondary curing is both 2000 mj / cm2 The difunctional UV crosslinking agent is polyurethane-modified diallyl oligomer DOUBLEMER® 5222, the trifunctional UV crosslinking agent is pentaerythritol triacrylate, the tetrafunctional UV crosslinking agent is tetrafunctional polyester acrylate ETERCURE 6325-100, and the UV initiator is diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide TPO.

[0095] The composition components of the resin grid layer in the above examples are summarized in Table 2 below:

[0096] Table 2 Composition Table of Resin Grid Layer

[0097]

[0098] Characterization and Testing:

[0099] I): The temperature resistance experiment of the grid release film prepared in the above Examples 1-5 was carried out, and the results are shown in Table 3 (judgment of dimensional stability under high-temperature baking):

[0100] Table 3 Temperature Resistance Experiment Results of Each Example and Comparative Example

[0101]

[0102] The comparative example is a grid release film prepared by the existing lamination process, and the material of the grid layer of the grid release film is PE material.

[0103] It can be obtained from Table 3 that the resin grid layer prepared by using the UV resin liquid of the present application, and the entire grid release film can be deformed at a temperature of 90~150°C and have high temperature resistance. Thus, the exhaust effect of the exhaust grooves formed on the surface of the pressure-sensitive adhesive coated on the grid release film is ensured to be stable.

[0104] II): Experiment on the correlation between the physical dimensions of the embossed ridges of the grid structure of the grid release film and the exhaust performance and disappearability of the exhaust grooves of the pressure-sensitive adhesive.

[0105] Next, we further explore the correlation between the physical dimensions of the embossed ridges (such as depth, width) and the node structure dimensions and the exhaust performance and disappearability of the exhaust grooves formed on the pressure-sensitive adhesive: taking the circumscribed circle diameter of the node structure, the depth of the embossed ridges, and the width of the embossed ridges as variables, and other conditions being the same (such as all using hexagonal grids, the composition and thickness of the UV resin grid layer being the same, the material of the substrate layer being the same, etc.), to explore the correlation between the physical dimensions of the embossed ridges and the exhaust performance and disappearability of the exhaust grooves, that is, to conduct a correlation orthogonal experiment (the influence factor table is shown in Table 4), and the orthogonal experiment results are shown in Table 5:

[0106] Table 4 Influence Factor Scheme Table

[0107]

[0108] Table 5 Results of orthogonal experiment

[0109]

[0110] Note: For the exhaust effect and the disappearable effect, performance tests need to be carried out after making them into tape products. This orthogonal experiment is carried out by making the same kind of single-sided disappearable reticulated tape (at least including a grid release film, a pressure-sensitive adhesive, and a substrate layer stacked in sequence from bottom to top), and making a comparative evaluation. The evaluation criteria are shown in Table 6 below:

[0111] Table 6 Evaluation criteria for the exhaust effect and the disappearable effect of the exhaust groove

[0112]

[0113] Note: The reticulation in Table 6 refers to the grid-shaped exhaust groove.

[0114] Among them, (1): Exhaustibility test: Cut the made single-sided disappearable reticulated tape into a size of 50mm×50mm under the environment of temperature 23±2°C and humidity 65±5%. Then attach the adhesive layer of the tape to the glass plate, and quickly rotate and press clockwise with fingers at the bubbling place in the middle of the tape to see its exhaust speed and whether it can exhaust air.

[0115] (2): Disappearability test: Cut the made single-sided disappearable reticulated tape into a size of 50×50mm. Tear off the grid release film on the tape, and flatly attach the grid adhesive surface to the white glass; roll it back and forth 3 times with a 2kg rubber roller (at a speed of 25mm / sec). Place the attached sample at room temperature, observe the disappearance of the reticulation every 1hr with an LED lamp and a magnifying glass, and record the disappearance time (observe all positions and record the disappearance time after determining that the reticulation has completely disappeared).

[0116] Therefore, from the results of the orthogonal experiment - Table 5, we can conclude that: the depth (height) of the embossed rib of the groove is 5 - 10um; the width of the embossed rib of the groove is 19 - 25um; the size of the node structure formed by the intersection of the embossed ribs of the groove is less than 30um (i.e., in the range of 15 - 30μm) is the best range. Within this range, when the exhaust groove transferred to the surface of the pressure-sensitive adhesive is actually attached to the item to be pasted, the bubbles in the exhaust groove can be discharged, and the exhaust groove can also completely disappear.

[0117] More preferably, when the depth of the grooved rib is 5 μm, the width of the grooved rib is 19 μm, and the diameter of the circumscribed circle of the node structure is 25 μm, the best exhaust effect and disappearable effect can be achieved; or when the depth of the grooved rib is 8 μm, the width of the grooved rib is 25 μm, and the diameter of the circumscribed circle of the node structure is 15 μm, the best exhaust effect and disappearable effect can be achieved; or when the depth of the grooved rib is 10 μm, the width of the grooved rib is 22 μm, and the diameter of the circumscribed circle of the node structure is 15 μm, the best exhaust effect and disappearable effect can be achieved. Coupled with the hexagonal grid and the UV resin grid layer, the prepared grid release film can be deformed at high temperature, and the bubbles in the exhaust grooves transferred to the pressure-sensitive adhesive can be quickly discharged while achieving the disappearable effect.

[0118] It should be understood that the various forms of the process shown above can be used, steps can be reordered, added or deleted. For example, the steps described in the present disclosure can be executed in parallel, sequentially or in a different order, as long as the desired results of the technical solutions disclosed in the present disclosure can be achieved, and no limitations are made herein.

[0119] In addition, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present disclosure, "a plurality" means two or more, unless otherwise specifically defined.

[0120] The above is only the specific implementation manner of the present disclosure, but the protection scope of the present disclosure is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present disclosure can easily think of changes or substitutions, which should all be covered by the protection scope of the present disclosure. Therefore, the protection scope of the present disclosure shall be subject to the protection scope of the claimed rights.

Claims

1. A grid release film, comprising a substrate layer and a resin grid layer stacked in sequence from bottom to top, wherein the resin grid layer has a grid structure formed on a side away from the substrate layer; characterized in that: The grid structure is composed of a plurality of hexagonal grids connected to each other, and the grooved convex strips formed between adjacent hexagonal grids intersect at the vertex positions of the hexagonal grids to form a node structure, the diameter of the circumscribed circle of the node structure is 15-30 μm, the depth of the grooved convex strips is 5-10 μm, and the width of the grooved convex strips is 19-25 μm; the circumscribed circle of the node structure is the circumscribed circle of a virtual triangle formed by the wide sides of adjacent grooved convex strips at the intersection position; The resin grid layer is configured to be able to remain unchanged at at least 100°C, and the resin grid layer is formed by UV resin liquid photocuring; the UV resin liquid includes the following raw materials in parts by weight: 100 parts of UV glue, 3 to 12 parts of UV cross-linking agent, and 3 to 4 parts of UV initiator; wherein the UV cross-linking agent is a mixture of one or more of a bifunctional UV cross-linking agent, a trifunctional UV cross-linking agent, and a tetrafunctional UV cross-linking agent.

2. The grid release film according to claim 1, characterized in that: The bifunctional UV crosslinking agent is a mixture of one or more of polyethylene glycol 400 diacrylate, 1,6-hexanediol diacrylate, and polyurethane modified diacrylate oligomer; The trifunctional UV crosslinking agent is a mixture of one or more of trimethylolpropane tris[3-(2-methylaziridinyl)propionate], trimethylolpropane triacrylate, and pentaerythritol triacrylate; The tetrafunctional UV crosslinking agent is a mixture of one or more of pentaerythritol tetraallyl ether and tetrafunctional polyester acrylate; The UV initiator is a mixture of one or more of 1-hydroxycyclohexyl phenyl ketone, diphenyl-(2,4,6-trimethylbenzoyl)phosphine oxide, 2-isopropylthioxanthone and isopropylthioxanthone.

3. The grid release film according to claim 1 or 2, characterized in that: It also includes a release layer, which is stacked on the grid structure of the resin grid layer.

4. A method for preparing a grid release film, applied to the grid release film according to any one of claims 1 to 3, characterized in that: The preparation method comprises: The UV resin liquid is transferred and coated onto the surface of the substrate layer by an anilox roller, and then UV initial curing is performed to initially form a resin grid layer with a grid structure on the surface of the substrate layer. The UV exposure during the UV initial curing is 500-2000 mj / cm 2 ; The substrate layer with the resin grid layer formed on the surface is subjected to UV secondary curing molding; wherein the UV exposure during UV secondary curing is 500~2000 mj / cm 2 .

5. The preparation method according to claim 4, characterized in that: The UV resin liquid comprises the following raw materials in parts by weight: 100 parts of UV glue, 3-12 parts of UV crosslinking agent, and 3-4 parts of UV initiator; wherein the UV crosslinking agent is a mixture of one or more of a bifunctional UV crosslinking agent, a trifunctional UV crosslinking agent, and a tetrafunctional UV crosslinking agent.

6. The preparation method according to claim 4, characterized in that: The preparation method further comprises: coating a release agent on the surface of the grid structure of the resin grid layer to form a release layer.

7. An adhesive tape, characterized in that: The invention comprises the grid release film according to any one of claims 1 to 3 or the grid release film prepared by the method according to any one of claims 4 to 6.

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