A liner paper

Abstract

The application discloses a lining paper, which comprises a main body layer, a glue layer and a first protective layer. The main body layer is stacked between the glue layer and the first protective layer and can be used for supporting the glue layer and the first protective layer. The glue layer comprises a first surface arranged away from the main body layer, the first surface comprises a plurality of first protruding parts and a plurality of first recessed parts, and the first recessed parts are arranged between adjacent first protruding parts. The first protruding parts can produce specular reflection on light, forming a highlight area. The first recessed parts can produce diffuse reflection, refraction or diffraction on light, forming a dark area or a color interference fringe. The plurality of first protruding parts and the plurality of first recessed parts jointly form a laser texture with a luster on the first surface, and the laser texture is configured to display first information. The laser texture is derived from an aluminum-free microstructure glue layer, thereby reducing the consumption of aluminum resources. The laser texture can present a visual effect with luster under light irradiation, and the anti-counterfeiting performance of the first information can be improved.

Description

Technical Field

[0001] This application relates to the field of packaging materials technology, and more particularly to an inner lining paper. Background Technology

[0002] In the packaging materials industry, especially in high-end tobacco, alcohol, and gift products, inner lining paper is widely used due to its excellent decorative effect. Traditional inner lining paper is usually manufactured using an aluminum transfer process, which consumes a large amount of aluminum, making the product expensive. Moreover, the aluminum foil is very thin and difficult to recycle, resulting in resource waste. Utility Model Content

[0003] This application provides an inner liner paper designed to improve the structure of the inner liner paper and reduce the consumption of aluminum resources.

[0004] In a first aspect, embodiments of this application provide an inner liner paper, which includes an adhesive layer, a main body layer, and a first protective layer. The main body layer is stacked between the adhesive layer and the first protective layer. The adhesive layer includes a first surface disposed opposite to the main body layer, the first surface including a plurality of first protrusions and a plurality of first recesses, with a first recess between adjacent first protrusions; the plurality of first protrusions and the plurality of first recesses together form a laser texture on the first surface, the laser texture being configured to display first information.

[0005] In some embodiments, the inner liner paper further includes a second protective layer disposed on the side of the adhesive layer opposite to the main body layer.

[0006] In some embodiments, the inner liner paper further includes a transfer film, which is peelably disposed on the first surface.

[0007] In some embodiments, the transfer film includes a base film layer and a first coating layer, the first coating layer being disposed facing the adhesive layer; the first coating layer includes a plurality of second protrusions and a plurality of second recesses, the second protrusions being embedded in the first recesses, and the first protrusions being recessed in the second recesses.

[0008] In some embodiments, the inner liner paper further includes an antibacterial layer disposed between the adhesive layer and the second protective layer.

[0009] In some embodiments, the height difference between the first protrusion and the first recess is 0.3 μm to 0.8 μm along the thickness direction of the adhesive layer.

[0010] In some embodiments, the thickness of the adhesive layer is 1 μm to 2 μm.

[0011] In some embodiments, the thickness of the base film layer is 10 μm to 20 μm.

[0012] In some embodiments, the thickness of the first coating is 3 μm to 5 μm.

[0013] In some embodiments, the inner liner paper further includes an adhesion layer disposed between the body layer and the adhesive layer.

[0014] Unlike existing technologies, this application provides an inner liner paper comprising a main layer, an adhesive layer, and a first protective layer. The main layer is stacked between the adhesive layer and the first protective layer, serving to support both layers. The adhesive layer includes a first surface facing away from the main layer. This first surface includes a plurality of first protrusions and a plurality of first recesses, with first recesses between adjacent protrusions. The first protrusions reflect light specularly, forming bright areas. The first recesses diffusely reflect, refract, or diffract light, forming dark areas or colored interference fringes. The protrusions and recesses together form a laser texture with a strong gloss on the first surface, configured to display first information. The direct source of the laser texture is an aluminum-free microstructure adhesive layer, reducing aluminum resource consumption and lowering the production cost of the inner liner paper. Furthermore, the glossy visual effect of the laser texture under light enhances the anti-counterfeiting performance of the first information.

[0015] Additional aspects and advantages of the embodiments of this application will be described, shown, or illustrated in part by way of implementation of the embodiments of this application in the following description. Attached Figure Description

[0016] One or more embodiments are illustrated by way of example with reference to the accompanying drawings, which are not intended to limit the embodiments, and elements having the same reference numerals in the drawings are designated as similar elements.

[0017] Figure 1 This is a schematic diagram of the structure of the inner lining paper provided in some embodiments of this application; Figure 2 This is a schematic diagram of the structure of laser textures provided in some embodiments of this application; Figure 3 These are physical images of laser textures provided in some embodiments of this application; Figure 4 This is a schematic diagram of the structure of the inner lining paper provided in some embodiments of this application; Figure 5 This is a schematic diagram of the structure of the inner lining paper provided in some embodiments of this application; Figure 6 These are schematic diagrams of the transfer membrane structure provided in some embodiments of this application; Figure 7This is a schematic diagram of the structure of the inner lining paper provided in some embodiments of this application; Figure 8 This is a schematic diagram of the structure of the inner lining paper provided in some embodiments of this application.

[0018] Figure label: 100. Inner lining paper; 10. Main body layer; 20. Adhesive layer; 21. First surface; 22. Laser texture; 221. First protrusion; 222. First depression; 30. First protective layer; 40. Second protective layer; 50. Transfer membrane; 51. Base film layer; 52. First coating layer; 60. Antibacterial layer; 70. Adhesion layer. Detailed Implementation

[0019] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0020] In this application, the reference to "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment that is mutually exclusive with other embodiments.

[0021] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0022] In the description of the embodiments in this application, the term "and / or" is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this document generally indicates that the preceding and following related objects have an "or" relationship.

[0023] The technical features involved in the different embodiments of this application described below can be combined with each other as long as they do not conflict with each other.

[0024] Firstly, this application proposes an inner lining paper 100, please refer to... Figure 1The inner liner paper 100 includes an adhesive layer 20, a main body layer 10, and a first protective layer 30.

[0025] The main body layer 10 is the main part of the inner liner paper 100, used to support the entire structure of the inner liner paper 100. The main body layer 10 is stacked between the adhesive layer 20 and the first protective layer 30, and can be used to support the adhesive layer 20 and the first protective layer 30. The main body layer 10 can be made of materials such as bleached sulfate wood pulp paper, glassine paper, or kaolin coated paper. The main body layer 10 needs to have a certain structural strength so that it is not easily damaged or deformed during subsequent processing and use.

[0026] The adhesive layer 20 is mainly the portion of the inner liner paper 100 used for displaying information, and its thickness is 1 μm to 2 μm. Please refer to... Figures 1 to 3 The adhesive layer 20 includes a first surface 21 disposed away from the main body layer 10. The first surface 21 includes a plurality of first protrusions 221 and a plurality of first recesses 222, with a first recess 222 between adjacent first protrusions 221. The plurality of first protrusions 221 and the plurality of first recesses 222 together form a laser texture 22 on the first surface 21, which is configured to display first information. The direct source of the laser texture 22 is the aluminum-free microstructure adhesive layer 20, reducing the consumption of aluminum resources. Moreover, the laser texture 22 can also exhibit a glossy visual effect under light, improving the anti-counterfeiting performance of the inner lining paper 100.

[0027] Specifically, the first protrusion 221, being a lens-shaped three-dimensional structure, produces specular reflection of light, forming a bright area. The first recess 222 produces diffuse reflection, refraction, or diffraction of light, forming dark areas or colored interference fringes. The effects of the two different areas are superimposed to form a glossy laser texture 22, thereby enhancing the visual effect of the inner lining paper 100.

[0028] The first protrusion and the first recess 222 are arranged in a certain regular pattern, so that the laser texture 22 can not only enhance the decorative effect of the inner lining paper 100, but also be used to display specific information, such as brand logo or anti-counterfeiting mark.

[0029] Furthermore, along the thickness direction of the adhesive layer 20, the height difference between the first protrusion and the first recess 222 is 0.3 μm to 0.8 μm. Optionally, the height difference can be 0.3 μm, 0.4 μm, 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, etc. This height difference makes the light reflection and refraction effect more delicate, presenting a richer color variation, and also gives the adhesive layer 20 a certain degree of flexibility.

[0030] In this embodiment, the adhesive layer 20 is primarily a glue system formulated from acrylic acid and polyurethane. This glue exhibits high film density, high gloss, and high folding resistance. After coating and heating curing, it forms a solid, transparent film. Specifically, the glue has a gloss level greater than 90 degrees, a viscosity of 15 Pa·s to 25 Pa·s, a solids content of 55% to 70%, and a coating wet weight of 7 g / m³. 2 Up to 10g / m 2 .

[0031] Acrylic acid is a resin or adhesive formed by the polymerization or copolymerization of acrylate monomers (such as methyl acrylate and butyl acrylate). Acrylic acid has high transparency, allowing the first information on the adhesive layer 20 to be clearly displayed. Polyurethane is a polymer material formed by the stepwise polymerization of isocyanate and polyol. The flexibility and film-forming properties of polyurethane can completely replicate the microstructure of the first protrusion 221 and the first depression 222 on the surface of the adhesive layer 20, reducing the collapse of the microstructure during the curing process and improving the structural stability of the adhesive layer 20. The composite of acrylic acid and polyurethane, with the high holding power and toughness of polyurethane, compensates for the brittleness of the acrylic adhesive layer 20 after long-term use, reducing the delamination and curling of the inner lining paper 100. It also protects the laser texture 22 on the surface of the adhesive layer 20 from external damage.

[0032] The first protective layer 30 is made of water-based acrylic waterproof barrier material. It possesses excellent waterproof and barrier properties, effectively reducing the penetration of external moisture or humidity into the inner liner paper 100, thus protecting the main layer 10 and adhesive layer 20 from moisture. The water-based acrylic material is environmentally friendly and non-toxic, meeting the requirements of modern packaging materials for green production. It also has good flexibility and adhesion, making the first protective layer 30 less prone to cracking or peeling during processing. Furthermore, the first protective layer 30 also has certain UV resistance, which can delay the aging or discoloration of the inner liner paper 100 caused by prolonged exposure to sunlight, further extending the product's lifespan.

[0033] In some embodiments, please refer to Figure 4The inner liner paper 100 also includes a second protective layer 40, which is disposed on the side of the adhesive layer 20 opposite to the main body layer 10. The second protective layer 40 is made of a water-based varnish of a water-based ester material. This water-based varnish is non-toxic, odorless, and highly transparent, and also possesses excellent abrasion resistance and scratch resistance, effectively protecting the adhesive layer 20 and the laser texture of the first surface 21 from external physical damage. The thickness of the second protective layer 40 is typically between 5μm and 10μm, providing protection without significantly increasing the overall thickness of the inner liner paper 100. Furthermore, the second protective layer 40 has good optical transparency, with a light transmittance exceeding 90%, ensuring that the first information on the adhesive layer 20 is clearly visible and does not affect the visual effect of the laser texture 22. The second protective layer 40 and the adhesive layer 20 can form a stable composite structure, further enhancing the durability and service life of the inner liner paper 100.

[0034] In some embodiments, please refer to Figure 5 and Figure 6 The inner liner 100 also includes a transfer film 50, which is peelably disposed on the first surface 21. The transfer film 50 further includes a base film layer 51 and a first coating layer 52, the first coating layer 52 being disposed facing the adhesive layer 20. The base film layer 51, serving as the support portion of the transfer film 50, has a thickness of 10 μm to 20 μm and is typically made of polyethylene terephthalate (PET) or polypropylene (OPP), giving it good mechanical strength and dimensional stability, allowing it to maintain its shape during molding. The first coating layer 52 is coated using an ultraviolet (UV) molding process, imprinting a textured pattern from a nickel plate onto the surface of the first coating layer 52 facing away from the base film layer 51. The first coating layer 52 is a resin coating with a thickness of 3 μm to 5 μm, possessing a certain degree of softness and plasticity, allowing it to adhere tightly to the first surface 21 of the adhesive layer 20, thus completely transferring the designed laser texture 22 to the first surface 21 of the adhesive layer 20 after the transfer film 50 is peeled off. The transferred film 50 retains its textured pattern after peeling, allowing for recycling. This not only improves production efficiency but also reduces the cost of creating the laser texture 22, mitigating the environmental issues associated with traditional aluminum transfer processes. Furthermore, the peeling process of the transferred film 50 is simple and efficient, significantly enhancing process stability and consistency in large-scale production.

[0035] Furthermore, the first coating 52 includes a plurality of second protrusions (not shown in the figure) and a plurality of second recesses (not shown in the figure). The second protrusions are embedded in the first recesses 222, and the first protrusions are recessed in the second recesses. The second protrusions and the first recesses 222 correspond one-to-one, and the first protrusions and the second recesses correspond one-to-one, so as to achieve accurate transfer of the laser texture 22 to the first surface 21 of the adhesive layer 20, thereby enabling high-precision replication of the laser texture 22.

[0036] Specifically, transfer adhesive is applied to the surface of the first coating layer 52, so that several second protrusions and several second depressions on the first coating layer 52 can be imprinted on the transfer adhesive. The first surface 21 of the main body layer 10 is bonded to the first coating layer 52 coated with transfer adhesive under a pressure of 5 bar to 8 bar. The mixture is dried at a temperature of 100°C to 140°C. After drying, the transfer film 50 is peeled off, and the transfer adhesive forms an adhesive layer 20 that adheres to the first surface 21, thus achieving high-precision replication of the laser texture 22.

[0037] In some embodiments, please refer to Figure 7 The inner liner 100 also includes an antibacterial layer 60, which is disposed between the adhesive layer 20 and the second protective layer 40. The antibacterial layer 60 can be made of natural or inorganic antibacterial agents. For example, the antibacterial layer 60 is composed of a silver ion antibacterial agent and a water-based polyurethane material, giving it excellent antibacterial properties and good adhesion. The silver ion antibacterial agent inhibits bacterial growth by slowly releasing silver ions, reducing microbial growth on the surface of the inner liner 100 and thus improving the product's hygiene and safety. The water-based polyurethane material gives the antibacterial layer 60 a certain degree of flexibility and abrasion resistance, making it less prone to cracking or peeling during use. Furthermore, the antibacterial layer 60 also has a certain degree of transparency, reducing obstruction of the laser texture 22 on the adhesive layer 20 and maintaining the decorative effect and information display function of the inner liner 100.

[0038] In some embodiments, please refer to Figure 8 The inner liner 100 also includes an adhesion layer 70, which is disposed between the main body layer 10 and the adhesive layer 20. The adhesion layer 70 may be made of modified polyurethane material, possessing excellent adhesive properties and effectively enhancing the bond between the main body layer 10 and the adhesive layer 20. Modified polyurethane, by introducing functional groups or crosslinking agents, improves its adaptability and adhesion to different materials, thereby reducing delamination during subsequent processing or use. Furthermore, the adhesion layer 70 also possesses good flexibility, maintaining a stable adhesive effect when the inner liner 100 is bent or folded, further improving the product's durability. The thickness of the adhesion layer 70 is 0.5 μm to 1 μm, providing sufficient adhesive strength without significantly increasing the overall thickness of the inner liner 100.

[0039] Furthermore, a second protective layer 40 can be disposed on the side of the adhesive layer 20 away from the adhesion layer 70 to improve the abrasion resistance and scratch resistance of the inner liner paper 100.

[0040] This application provides an inner liner paper 100, which includes a main layer 10, an adhesive layer 20, and a first protective layer 30. The main layer 10 is stacked between the adhesive layer 20 and the first protective layer 30, and can be used to support the adhesive layer 20 and the first protective layer 30. The adhesive layer 20 includes a first surface 21 disposed away from the main layer 10. The first surface 21 includes a plurality of first protrusions 221 and a plurality of first recesses 222, with a first recess 222 between adjacent first protrusions 221. The first protrusions 221 produce specular reflection of light, forming bright areas. The first recesses 222 produce diffuse reflection, refraction, or diffraction of light, forming dark areas or colored interference fringes. The plurality of first protrusions 221 and the plurality of first recesses 222 together form a laser texture 22 with a strong gloss on the first surface 21. The direct source of the laser texture 22 is the aluminum-free microstructure adhesive layer 20, which reduces the consumption of aluminum resources and can reduce the production cost of the inner liner paper. In addition, the laser texture 22 is configured to display the first information. Under light, the laser texture 22 can also present a glossy visual effect, which can improve the anti-counterfeiting performance of the first information.

[0041] Example 1 (1) A PET film with a thickness of 15 μm is selected as the base film layer. A UV coating molding process is used to imprint the laser texture engraved on the nickel plate onto the surface of the first coating layer away from the base film layer, so that the first coating layer has several second protrusions and several second depressions, thereby obtaining a transfer film. The first coating layer is a resin coating with a thickness of 3 μm.

[0042] (2) Select kaolin coated paper as the main layer, coat the surface of the main layer with a layer of water-based acrylic acid, and dry the water-based acrylic acid to form the first protective layer.

[0043] (3) Acrylic acid and polyurethane are compounded to form a transfer adhesive. The transfer adhesive is applied to the surface of the first coating so that a number of second protrusions and a number of second depressions on the first coating can be printed on the transfer adhesive. The first surface of the main layer is bonded to the first coating coated with the transfer adhesive under a pressure of 6 bar. After drying at a temperature of 120°C, the transfer film is peeled off. The transfer adhesive forms an adhesive layer that adheres to the first surface. The first surface includes a number of first protrusions and a number of first depressions to obtain the inner liner paper.

[0044] Example 2 (1) A PET film with a thickness of 15 μm is selected as the base film layer. A UV coating molding process is used to imprint the laser texture engraved on the nickel plate onto the surface of the first coating layer away from the base film layer, so that the first coating layer has several second protrusions and several second depressions, thereby obtaining a transfer film. The first coating layer is a resin coating with a thickness of 3 μm.

[0045] (2) Select kaolin coated paper as the main layer, coat the surface of the main layer with a layer of water-based acrylic acid, and dry the water-based acrylic acid to form the first protective layer.

[0046] (3) Acrylic acid and polyurethane are compounded to form a transfer adhesive. The transfer adhesive is applied to the surface of the first coating so that a number of second protrusions and a number of second depressions on the first coating can be printed on the transfer adhesive. The first surface of the main layer is bonded to the first coating coated with the transfer adhesive under a pressure of 6 bar. After drying at a temperature of 120°C, the transfer film is peeled off and the transfer adhesive forms an adhesive layer that adheres to the first surface. The first surface includes a number of first protrusions and a number of first depressions.

[0047] (4) Apply water-based varnish to the surface of the adhesive layer and dry it at 100°C. The water-based varnish forms a second protective layer on the surface of the adhesive layer, thus obtaining the inner lining paper.

[0048] Comparative Example 1 Choose commercially available liner paper prepared using aluminum transfer methods.

[0049] Comparative Example 2 (1) A PET film with a thickness of 15 μm was selected as the base film layer. A UV coating molding process was used to coat the first coating layer onto the surface of the base film layer to obtain a transfer film. The first coating layer is a resin coating with a thickness of 3 μm.

[0050] (2) Select kaolin coated paper as the main layer, coat the surface of the main layer with a layer of water-based acrylic acid, and dry the water-based acrylic acid to form the first protective layer.

[0051] (3) Acrylic acid and polyurethane are compounded to form a transfer adhesive. The transfer adhesive is applied to the surface of the first coating. The first surface of the main layer is bonded to the first coating with the transfer adhesive under a pressure of 6 bar. After drying at 120°C, the transfer film is peeled off. The transfer adhesive forms an adhesive layer that adheres to the first surface to obtain the inner lining paper.

[0052] Ten sheets of lining paper prepared in Example 1, Example 2 and Comparative Example 1 were selected and subjected to the following experimental tests: adhesion test, aging test, freeze resistance test, abrasion resistance test and back moisture resistance test.

[0053] Adhesion test method: A peel tester was used to conduct a destructive test on the adhesive layer using 3M strong adhesive tape.

[0054] The aging test method is as follows: the inner lining paper is placed in an incubator at a temperature of 60 degrees Celsius and observed after 24 hours.

[0055] Method for antifreeze test: Place the inner lining paper in a test chamber at a temperature of -15 degrees Celsius and observe after 12 hours.

[0056] Method for abrasion resistance test: The inner lining paper is tested using an abrasion resistance tester.

[0057] Method for moisture protection on the back: Test the lining paper using a water absorption tester.

[0058] The experimental results are shown in Table 1: Table 1

[0059] As shown in Table 1, the adhesive layers in both the examples and comparative examples did not peel off, indicating that the adhesion of both examples and comparative examples meets the usage requirements. During the aging test, the lining paper in both examples and comparative examples did not show any yellowing or darkening. This indicates that the lining paper in both examples and comparative examples has good anti-aging performance. The gloss of the lining paper in the examples is greater than 90 degrees, but the lining paper in Comparative Example 2 has no gloss, indicating that Comparative Example 2 cannot be used for pattern recognition, has poor clarity, and cannot meet the brand display and anti-counterfeiting requirements of the product. Furthermore, the gloss of the lining paper in the examples and the lining paper in Comparative Example 1 is greater than 90 degrees, indicating that the gloss of the lining paper prepared in this application is comparable to that of the lining paper prepared by the aluminum transfer method, but the production cost of the lining paper prepared in this application is lower.

[0060] Comparing the results of the freeze-thaw resistance and abrasion resistance tests of Example 1 and Comparative Example 1, it can be seen that the lining paper in Example 1 has comparable performance to the lining paper in Comparative Example 1. This indicates that the lining paper prepared in the embodiments of this application meets commercially available standards in both freeze-thaw resistance and abrasion resistance.

[0061] Comparing Examples 1, 2, and 2, it is evident that Example 2 exhibits approximately 14% higher flexural strength than Example 1 and approximately 21% to 43% higher than Comparative Example 2. This indicates that the inner liner paper of Example 2 demonstrates the best flexibility and flexural strength at low temperatures. This is likely because the second protective layer protects the adhesive layer and the main body layer, reducing low-temperature damage and maintaining the flexibility of the inner liner paper to a certain extent. Example 2 also shows approximately 29% to 34% higher abrasion resistance than Example 1 and approximately 33% to 57% higher than Comparative Example 2. This is likely due to the second protective layer possessing certain abrasion resistance properties, resulting in significantly better surface abrasion protection, resisting friction damage during product storage, transportation, and unpacking, and ensuring the laser texture. Both the examples and the comparative examples have a water absorption rate of less than 3%, indicating that the inner liner paper effectively blocks external moisture, reducing the brittleness of the main body layer due to moisture.

[0062] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them; under the concept of this application, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations of different aspects of this application as described above, which are not provided in detail for the sake of brevity; although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A type of inner lining paper, characterized in that, Includes an adhesive layer, a main body layer, and a first protective layer; The main body layer is stacked between the adhesive layer and the first protective layer; The adhesive layer includes a first surface disposed away from the main body layer. The first surface includes a plurality of first protrusions and a plurality of first recesses, with a first recess between adjacent first protrusions. The plurality of first protrusions and the plurality of first recesses together form a laser texture on the first surface, and the laser texture is configured to display first information.

2. The inner lining paper according to claim 1, characterized in that, The inner liner paper also includes a second protective layer, which is disposed on the side of the adhesive layer opposite to the main body layer.

3. The inner lining paper according to claim 1, characterized in that, The inner liner paper also includes a transfer film, which is peelably disposed on the first surface.

4. The inner lining paper according to claim 3, characterized in that, The transfer film includes a base film layer and a first coating layer, the first coating layer being disposed facing the adhesive layer; the first coating layer includes a plurality of second protrusions and a plurality of second recesses, the second protrusions being embedded in the first recesses, and the first protrusions being recessed in the second recesses.

5. The inner lining paper according to claim 2, characterized in that, The inner lining paper also includes an antibacterial layer, which is disposed between the adhesive layer and the second protective layer.

6. The inner lining paper according to any one of claims 1 to 5, characterized in that, Along the thickness direction of the adhesive layer, the height difference between the first protrusion and the first depression is 0.3 μm to 0.8 μm.

7. The inner lining paper according to any one of claims 1 to 5, characterized in that, The thickness of the adhesive layer is 1 μm to 2 μm.

8. The inner lining paper according to claim 4, characterized in that, The thickness of the base film layer is 10 μm to 20 μm.

9. The inner lining paper according to claim 4, characterized in that, The thickness of the first coating is 3 μm to 5 μm.

10. The inner lining paper according to claim 1, characterized in that, The inner liner paper also includes an adhesion layer, which is disposed between the main body layer and the adhesive layer.

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