Surface structured release film

Abstract

The surface structure release film provided by the application relates to the technical field of film materials for certificates; the device comprises a base material layer, a structure layer and a release layer, both surfaces of the base material layer are provided with a pre-coated bottom layer; the structure layer is arranged on the outer side of the pre-coated bottom layer, wherein a plurality of spherical functional particles are added to the structure layer; the release layer is arranged on the outer side of the structure layer; the plurality of spherical functional particles protrude from the surfaces of the structure layer and the release layer; the surface structure release film provided by the present application has excellent properties such as good thermal stability, high mechanical strength, excellent peeling performance, delicate surface frosted structure, repeated use, and greatly reduced production cost, and can be effectively applied in various bonding and transfer scenarios such as IMR.

Description

Technical Field

[0001] This utility model relates to the field of film materials for documents, and specifically to a surface structure release film. Background Technology

[0002] Existing release films typically rely on low surface energy coatings for peeling, making it difficult to simultaneously meet the triple requirements of "high release, high conformity, and high transferability." Domestic and international researchers have attempted to fabricate microstructures on PET, BOPET, TPX, or PI substrates using techniques such as UV embossing, thermoforming, laser direct writing, and soft embossing. However, these methods generally suffer from low structural fidelity, poor batch-to-batch consistency, and structural collapse after high-temperature pressing, limiting their large-scale application in high-end scenarios such as IMR, IML, OMD, and 3D hot bending. Utility Model Content

[0003] The purpose of this invention is to provide a surface structure release film to solve the technical problems of low structural fidelity, poor batch consistency, and structural collapse after high-temperature pressing in the prior art.

[0004] For the purposes described above, this application provides a surface structure release film, comprising:

[0005] A substrate layer, wherein a pre-coated underlayer is provided on both sides of the substrate layer;

[0006] A structural layer is provided on the outside of the pre-coated base layer, wherein a number of spherical functional particles are added to the structural layer;

[0007] Release layers, wherein the release layers are respectively disposed on the outer side of the structural layers;

[0008] Among them, several of the spherical functional particles protrude from the surfaces of the structural layer and the release layer.

[0009] Furthermore, the substrate layer is made of PET material.

[0010] Furthermore, the thermal shrinkage rate of the substrate layer is ≤1.0% in the longitudinal direction (MD) and ≤0.3% in the transverse direction (TD).

[0011] Furthermore, the thickness of the substrate layer does not exceed 30 μm.

[0012] Furthermore, the pre-coated substrate is made of acrylic resin and has a thickness of 40nm-80nm.

[0013] Furthermore, the structural layer is coated with a polyurethane acrylate resin with a thickness of 8μm-12μm.

[0014] Furthermore, the spherical functional particles are spherical silica particles with a particle size distribution of 8 μm monodisperse particles.

[0015] Furthermore, the release layer is a coated silicone release layer with a coating thickness of 70nm-150nm.

[0016] Furthermore, the surface roughness Ra value of both sides of the surface structure release film is 1.0 μm-2.0 μm.

[0017] By adopting the above technical solution, the surface structure release film provided in this application has the following technical advantages compared with the prior art:

[0018] In this solution, both sides of the substrate layer are coated with a pre-coated underlayer, which increases the adhesion of the substrate surface and enhances the adhesion of the structural layer to the substrate surface, ensuring that the structural layer can be stably attached to the pre-coated layer. The pre-coated underlayer is coated with a structural layer on both sides, which solves the problem of warping and curling caused by single-layer coating of structural layer at high temperature, and achieves stable flatness during repeated use of the surface structure release film. Spherical functional particles are added to the structural layer and cleverly protruded on the surface of the film material, which greatly improves the mechanical strength and temperature resistance of the film material, ensuring the stability of the coating during high-temperature bonding and transfer process, and preventing defects such as delamination and cracking. On the other hand, the raised structure formed by the spherical functional particles can control the surface roughness of the membrane material, so that the surface of the membrane material can present a delicate frosted feel, which can be well displayed in the end product after the transfer is completed; the outermost layer of the surface structure release film is set with a release coating, which can not only achieve excellent peeling effect, but also ensure that the delicate microstructure of the surface is not affected. In the actual downstream use, it can maintain the stability of peeling effect for a long time, and has the advantages of high overall structural fidelity, good batch consistency and stable structure after high temperature pressing. Attached Figure Description

[0019] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0020] Figure 1 This is a schematic diagram of the surface structure release film provided in the embodiments of this application.

[0021] Icons: 1-Substrate layer; 2-Pre-coated undercoat; 3-Structural layer; 4-Release layer; 5-Spherical functional particles. Detailed Implementation

[0022] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0023] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0024] This application provides a surface structure release film with excellent properties such as good thermal stability, high mechanical strength, excellent peel performance, fine surface frosted structure, reusability, and greatly reduced production costs. It can be effectively applied in various bonding and transfer scenarios such as IMR.

[0025] like Figure 1 As shown, the surface structure release film includes a substrate layer 1, a structural layer 3, and a release layer 4; wherein:

[0026] The substrate layer 1 is preferably made of PET (polyethylene terephthalate). The substrate of substrate layer 1 requires a longitudinal thermal shrinkage rate (MD) ≤ 1.0% and a transverse thermal shrinkage rate (TD) ≤ 0.3%. During the high-temperature lamination and transfer process, the thermal stability of the transfer carrier is a key factor determining the success of the product manufacturing process. Excellent thermal shrinkage performance ensures that substrate layer 1 will not experience thermodynamic problems at high temperatures. In actual production, there are certain requirements for the thickness of the release film on the surface structure, which should not exceed 50 μm. This requires that the thickness of substrate layer 1 should not exceed 30 μm, preferably 25 μm. Typically, a 25 μm thick PET substrate meets the above requirements.

[0027] Both sides of the substrate layer 1 are provided with a pre-coated underlayer 2; the pre-coated underlayer 2 is made of acrylic resin, and the PET substrate with the pre-coated underlayer 2 can effectively improve the adhesion to the outer coating, and improve stability and reliability.

[0028] In this embodiment, preferably, an online coated PET substrate is used, such as the Hefei Lucky 2 pre-coated bottom layer optical polyester film FG22-25μm double-sided bottom coating product, and the thickness of the pre-coated bottom layer 2 is 40nm-80nm.

[0029] Structural layers 3 are respectively disposed on the outer side of the pre-coated underlayer 2. Structural layers 3 are preferably made of acrylic resin coatings. Structural layers 3 possess special high-temperature resistance and excellent adhesion properties, maintaining stable structural integrity during high-temperature bonding and transfer processes, without exhibiting performance defects such as delamination, cracking, or adhesive transfer. The double-sided structural layer 3 design of the surface release film solves the warping and curling problems caused by mismatched thermal shrinkage of single-layer structural layers 3, ensuring long-term reliability. In this embodiment, preferably, polyurethane acrylate, such as Sartoma CN8010NS polyurethane acrylate resin material, is used, and the thickness of structural layer 3 is controlled to 8μm-12μm using a UV-cured coating process.

[0030] The structural layer 3 contains several spherical functional particles 5. These spherical functional particles are spherical silica particles. Due to the extremely strong bond energy of the silicon-oxygen bonds and the stable tetrahedral structure of the silica particles, they exhibit high hardness and excellent temperature resistance, greatly enhancing the mechanical strength and temperature resistance of the structural layer 3. Furthermore, the raised structure enables the control of the surface roughness of the film material. By controlling the particle size, monodispersity, and coating process, the roughness Ra value is controlled within the range of 1.0 μm to 2.0 μm, achieving a fine, frosted surface structure.

[0031] In this embodiment, spherical silica particles are added to a polyurethane acrylate resin coating solution, and the particle distribution structure in structural layer 3 is obtained by UV curing through a coating process. Preferably, Tosoh Silicon Chemical E-150J spherical silica particles are used, with an average particle size of 8 μm, and the surface roughness Ra value of the release film is controlled at around 1.25 μm.

[0032] Release layers 4 are respectively disposed on the outer side of structural layer 3; wherein, a number of spherical functional particles 5 protrude from the surface of structural layer 3 and release layer 4.

[0033] In this embodiment, release layer 4 is the contact layer that directly contacts the transfer material, requiring excellent temperature resistance, easy peeling performance, and low transfer performance, while having no impact on the raised structure of the film surface. This necessitates that release layer 4 be thin, fully cured, and have good adhesion to structural layer 3; the silicone release agent has good temperature resistance and low peeling force, achieving excellent peeling performance. Through coating process control, an ultra-thin coating thickness, at the nanometer level, can be achieved without affecting the surface structure of structural layer 3.

[0034] In this embodiment, preferably, a micro-recessed coating thermosetting process is used to coat a release layer 4 on the surface of the structural layer 3, and the dry thickness of the release layer 4 is controlled between 70nm and 150nm. The release layer 4 is made of silicone release coating, preferably Wacker DEHESIVE 944 silicone release agent.

[0035] Compared with the prior art, the surface structure release film provided in this application has at least the following advantages:

[0036] 1. The substrate layer 1 uses a PET substrate with good thermal stability and limits the range of heat shrinkage rate to ensure that the film will not have problems such as heat wrinkles or heat tension lines during high-temperature lamination and transfer.

[0037] The substrate layer 1 is coated with a pre-coated base layer 2 on both sides, which increases the adhesion of the substrate surface and enhances the adhesion of the structural layer 3 to the substrate surface, ensuring that the structural layer 3 can be stably adhered to the pre-coated layer.

[0038] 2. Both sides of the pre-coated base layer 2 are coated with structural layers 3, which solves the problem of warping and curling caused by single-layer coating of structural layers 3 at high temperatures, and achieves stable flatness during repeated use of the surface structure release film.

[0039] 3. Inorganic functional particles are added to structural layer 3 and cleverly protruded onto the membrane surface, significantly improving the membrane's application performance. On one hand, due to the extremely strong bond energy and stable tetrahedral structure of silicon oxide particles, the silicon oxide particles have high hardness and excellent temperature resistance, greatly enhancing the mechanical strength and temperature resistance of structural layer 3. This ensures the stability of the coating during high-temperature bonding and transfer printing, preventing defects such as delamination and cracking. On the other hand, the protruding structure allows for the control of the membrane surface roughness. By controlling the particle size, monodispersity, and coating process, the roughness Ra value is controlled within 1.0μm-2.0μm, resulting in a fine, frosted surface that is excellently displayed in the final product after transfer printing.

[0040] 4. A release coating is applied to the outermost layer of the surface structure release film. The thickness of the release coating is precisely controlled to achieve excellent peeling performance while ensuring that the delicate microstructure of the surface is not affected. The silicone release coating is only a thin layer, providing good peeling performance and excellent bonding with structural layer 3. In downstream applications, it can maintain stable peeling performance over a long period of time.

[0041] In this implementation scheme, the design of the double-sided coating of the release film on the surface structure solves the problem of easy warping of the single-sided coating. On the other hand, the identical structure and performance on both sides enable the excellent performance of multiple interchangeable and reusable front and back sides, which greatly reduces the production cost for downstream users.

[0042] In summary, the surface release film of this application has excellent properties such as good thermal stability, high mechanical strength, excellent peel performance, fine surface frosted structure, reusability, and greatly reduced production costs, and can be effectively applied in various bonding and transfer scenarios such as IMR.

[0043] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such 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 utility model.

Claims

1. A surface-structured release film, characterized in that, include: A substrate layer, wherein a pre-coated underlayer is provided on both sides of the substrate layer; A structural layer is provided on the outside of the pre-coated base layer, wherein a number of spherical functional particles are added to the structural layer; Release layers, wherein the release layers are respectively disposed on the outer side of the structural layers; Among them, several of the spherical functional particles protrude from the surfaces of the structural layer and the release layer.

2. The surface structure release film according to claim 1, characterized in that, The substrate layer is made of PET material.

3. The surface structure release film according to claim 1, characterized in that, The thermal shrinkage rate of the substrate layer is ≤1.0% in the longitudinal direction (MD) and ≤0.3% in the transverse direction (TD).

4. The surface structure release film according to claim 1, characterized in that, The thickness of the substrate layer does not exceed 30 μm.

5. The surface structure release film according to claim 1, characterized in that, The pre-coated underlayer is made of acrylic resin and has a thickness of 40nm-80nm.

6. The surface structure release film according to claim 1, characterized in that, The structural layer is coated with a polyurethane acrylate resin with a thickness of 8μm-12μm.

7. The surface structure release film according to claim 1, characterized in that, The spherical functional particles are spherical silica particles with a particle size distribution of 8 μm monodisperse particles.

8. The surface structure release film according to claim 1, characterized in that, The release layer is a coated silicone release layer with a coating thickness of 70nm-150nm.

9. The surface structure release film according to claim 1, characterized in that, The surface roughness Ra of the two sides of the release film is 1.0 μm-2.0 μm.

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