A low-tack self-adhesive release film and a method for making the same
By using a six-layer composite structure design and multi-level buffer layers, the problem of peeling and lifting of the release film under temperature changes is solved. This reduces peeling difficulties at high temperatures and avoids lifting at low temperatures, thereby improving the stability and adhesion reliability of the film.
Patent Information
- Application Number
- CN202610391096.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-03-27
- Publication Date
- 2026-06-26
AI Technical Summary
Existing release films are difficult to peel off and easily damaged at high temperatures when the ambient temperature changes, and they are not firmly bonded and easily lift up at low temperatures, resulting in damage to the integrity of the film and contamination of the substrate.
It adopts a six-layer composite structure design, including a substrate layer, a first buffer layer, a heat-stabilized layer, a second buffer layer, an elastic reinforcement layer, and an improved release layer. Through hot-pressing and roller coating processes, multi-level buffers are formed. Heat stabilizers, nanofillers, and temperature-responsive polymers are used to absorb thermal stress, stabilize the molecular structure, and improve flexibility and adhesion.
It reduces peeling difficulties and curling when temperature changes, maintains film integrity and bonding reliability, prevents film deformation and substrate contamination, and improves the environmental resistance of the bonding system.
Smart Images
Figure CN122275411A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of release film technology, specifically to a low-viscosity self-adhesive release film and its preparation method. Background Technology
[0002] Release film is a thin film material with low or slight tack on its surface. Its core characteristic is that it allows sticky substances to adhere, which is intended to facilitate subsequent peeling.
[0003] However, existing release films are extremely sensitive to environmental changes during use because their coatings are very fragile to heat at the molecular level. When the external temperature rises, the molecular motion inside the release layer intensifies, just like sugar dissolves more easily in hot water. Heat causes the intermolecular distance to widen and vibrate more, thus changing the surface energy and further amplifying the van der Waals forces and hydrogen bonds between the interface molecules. This leads to an increase in the interfacial force between the release film and the self-adhesive layer, and the force required for peeling also increases. This increased force makes it difficult for the film to detach smoothly from the substrate, resulting in stretching deformation or even breakage. This not only damages the integrity of the film but also leaves debris that contaminates the substrate surface. When the ambient temperature drops, the flexibility of the release layer weakens because molecular motion tends to be static at low temperatures. The coating becomes stiff and lacks elasticity, and the surface energy drops too quickly, just like a frozen rubber band becomes brittle and easy to break. This results in insufficient contact between the self-adhesive layer and the release layer, causing poor adhesion or automatic lifting during use. This insufficient contact creates tiny air gaps, further amplifying the tendency to separate, causing the entire bonding interface to fail immediately under slight vibration or stress. Summary of the Invention
[0004] Technical problems to be solved To address the shortcomings of existing technologies, this invention provides a low-adhesion self-adhesive release film and its preparation method, which solves the problems of release films being sensitive to changes in ambient temperature, increasing release force at high temperatures leading to difficult peeling, film damage and substrate contamination, and poor adhesion and easy lifting and failure at low temperatures.
[0005] (II) Technical Solution To achieve the above objectives, the present invention provides the following technical solution: A low-tack self-adhesive release film includes: a substrate layer, a first buffer layer, a heat-stabilizing layer, a second buffer layer, an elastic reinforcing layer, and an improved release layer. The substrate layer uses a polyester film as a support structure to provide mechanical strength and dimensional stability. The first buffer layer is disposed on the substrate layer and tightly bonded to it via hot-pressing to initially absorb thermal stress. The heat-stabilizing layer is disposed on the first buffer layer and uniformly bonded to its surface via a coating process, containing heat stabilizers and nanofillers to buffer the effects of temperature changes on molecular motion. The second buffer layer is disposed on the heat-stabilizing layer and tightly bonded to it via hot-pressing to further isolate thermal stress and enhance interlayer adhesion. The elastic reinforcing layer is coated on the second buffer layer and uniformly bonded to its surface via a roll coating process, containing elastic additives to improve the coating's flexibility at low temperatures. The improved release layer is coated on the elastic reinforcing layer and uniformly bonded to its surface via a roll coating process, employing a silicon-based coating incorporating temperature-responsive polymers and elastic additives.
[0006] Preferably, the substrate layer is a polyethylene terephthalate (PET) film with a thickness of 20 μm-100 μm, providing high tensile strength and thermal stability.
[0007] Preferably, the first buffer layer is a polyimide (PI) film with a thickness of 5μm-15μm, which is bonded to the substrate layer by a hot-pressing composite process at a temperature of 300°C-350°C and a pressure of 2MPa-5MPa to absorb initial thermal stress and improve interlayer adhesion.
[0008] Preferably, the heat-stabilized layer contains a benzotriazole heat stabilizer and silica nanofiller, wherein the heat stabilizer content is 1wt%-5wt% and the nanofiller particle size is 10nm-50nm. After being dispersed in a solvent, it is coated onto the first buffer layer and thermo-cured at 150°C-200°C to form a stable layer with a thickness of 5μm-20μm. The second buffer layer is a polyurethane (PU) film with a thickness of 5μm-10μm. It is bonded to the heat-stabilized layer by a hot-pressing composite process at a temperature of 250°C-300°C and a pressure of 1MPa-3MPa to further isolate thermal stress and enhance interlayer bonding strength. The elastic reinforcing layer is a mixture of polyurethane elastomer and nitrile rubber (NBR) with a mixing ratio of 3:1 to 5:1 and a coating thickness of 3μm-8μm. It is bonded to the second buffer layer by a roller coating process and dried and cured at 120°C-150°C to improve the coating flexibility at low temperatures.
[0009] Preferably, the improved release layer uses polydimethylsiloxane (PDMS) as the silicone-based coating matrix, incorporates poly(N-isopropylacrylamide) (PNIPAM) as a temperature-responsive polymer and polyurethane elastomer as an elastic additive, wherein the content of the temperature-responsive polymer is 2wt%-10wt% and the content of the elastic additive is 1wt%-8wt%. After mixing and stirring, it is roll-coated onto the elastic reinforcing layer and cured under ultraviolet light to form a release layer with a thickness of 1μm-10μm. The improved release film utilizes the temperature-responsive polymer in the improved release layer, the heat stabilizer in the heat-stabilizing layer, and the nanofiller. The improved release film is linked to the thermal stress absorption function of the first and second buffer layers. The elastic reinforcement layer and the elastic additives in the improved release film, the flexible support of the first and second buffer layers, and the nanofiller of the thermal stability layer are linked. The improved release film adopts a six-layer composite structure design. Through the multi-level buffering of the first buffer layer, the thermal stability layer, the second buffer layer and the elastic reinforcement layer, and the linkage of the improved release layer, when the temperature changes, the first and second buffer layers absorb thermal stress, the thermal stability layer stabilizes the molecular structure, and the elastic reinforcement layer improves low-temperature flexibility.
[0010] A method for preparing a low-viscosity self-adhesive release film, applied to the low-viscosity self-adhesive release film according to any one of claims 1-5, further includes the following preparation method: Step 1: Prepare the substrate layer. Select polyethylene terephthalate (PET) film as the substrate layer with a thickness of 20μm-100μm, and ensure that its surface is clean and free of impurities. Step 2: Add the first buffer layer. Place the polyimide (PI) film on the substrate layer and laminate it using a hot-pressing process at a temperature of 300°C-350°C and a pressure of 2MPa-5MPa to form a first buffer layer with a thickness of 5μm-15μm. Step 3: Add a heat-stabilized layer. Disperse benzotriazole heat stabilizer (1wt%-5wt%) and silica nanofiller (10nm-50nm particle size) in a solvent and coat them onto the surface of the first buffer layer. Then, heat-cure at 150°C-200°C to form a heat-stabilized layer with a thickness of 5μm-20μm. Step 4: Add a second buffer layer. Place the polyurethane (PU) film on the heat-stabilized layer and laminate it using a hot-pressing process at a temperature of 250°C-300°C and a pressure of 1MPa-3MPa to form a second buffer layer with a thickness of 5μm-10μm. Step 5: Add an elastic reinforcement layer. Mix polyurethane elastomer and nitrile rubber (NBR) at a mixing ratio of 3:1 to 5:1, apply the mixture to the surface of the second buffer layer using a roller coating process, and dry and cure at 120°C-150°C to form an elastic reinforcement layer with a thickness of 3μm-8μm. Step Six: Add an improved release layer. Polydimethylsiloxane (PDMS) is used as the silicone-based coating matrix. Poly(N-isopropylacrylamide) (PNIPAM) with a content of 2wt%-10wt% is incorporated as a temperature-responsive polymer, and polyurethane elastomer with a content of 1wt%-8wt% is incorporated as an elastic additive. After mixing and stirring, the mixture is roller-coated onto the surface of the elastic reinforcement layer and cured under ultraviolet light to form an improved release layer with a thickness of 1μm-10μm.
[0011] Preferably, in step one, the polyethylene terephthalate (PET) film undergoes plasma surface treatment before preparation to improve surface roughness and adhesion, ensuring a tight bond between the first buffer layer and the substrate layer. In step three, the solvent dispersion of the heat-stabilizing layer uses a solvent of ethanol and water mixed in a 1:1 volume ratio. During coating, a doctor blade coating method is used, and the coating speed is controlled at 0.5 m / min-2 m / min to ensure the uniform distribution of the heat stabilizer and nanofiller.
[0012] Preferably, in step four, the hot-pressing composite process of the second buffer layer is carried out in a vacuum environment with a vacuum degree of 0.01MPa-0.05MPa. In step five, 1wt%-3wt% of silane coupling agent is added to the mixture of polyurethane elastomer and nitrile rubber (NBR) before mixing.
[0013] Preferably, in step six, the improved release layer is coated using a two-roller coater, with the coating temperature controlled at 25°C-40°C and the coating speed at 1m / min-3m / min.
[0014] Preferably, in step six, the ultraviolet curing uses ultraviolet light with a wavelength of 365nm, the curing time is 30s-60s, and the ultraviolet light intensity is 100mW / cm². 2 -200mW / cm 2 .
[0015] (III) Beneficial Effects Compared with the prior art, the present invention provides a low-viscosity self-adhesive release film and its preparation method, which has the following beneficial effects: 1. This low-adhesion self-adhesive release film and its preparation method utilize a six-layer composite structure design. Through the linkage of a multi-level buffer layer, a thermally stable layer, a second buffer layer, and an elastic reinforcing layer, and an improved release layer, when the temperature changes, the first and second buffer layers absorb thermal stress, the thermally stable layer stabilizes the molecular structure, and the elastic reinforcing layer improves low-temperature flexibility. Overall, it prevents the surface energy fluctuation from amplifying the changes in interfacial forces, thereby reducing peeling difficulties and deformation at high temperatures and avoiding insufficient contact and lifting at low temperatures. The synergistic effect of the six-layer structure further solves the overall instability caused by temperature sensitivity, reduces bonding misalignment and automatic peeling during production, and improves the reliability and environmental resistance of the bonding system.
[0016] 2. This low-adhesion self-adhesive release film and its preparation method utilize the improved settings of temperature-responsive polymer in the release layer and heat stabilizer and nanofiller in the heat-stabilized layer. When the external temperature rises, the temperature-responsive polymer inhibits the intensification of molecular motion through a dynamic cross-linking network, preventing thermal energy from causing the intermolecular spacing to expand and vibration to accelerate, thereby stabilizing the surface energy and preventing the amplification of van der Waals forces and hydrogen bonding between interfacial molecules, which would lead to an increase in interfacial forces. The heat stabilizer and nanofiller in the heat-stabilized layer work in conjunction with the thermal stress absorption functions of the first and second buffer layers to further reduce the tensile deformation and rupture of the film caused by the increase in peel force, maintain the integrity of the film, and prevent residual fragments from contaminating the substrate surface.
[0017] 3. This low-adhesion self-adhesive release film and its preparation method utilize the setting of elastic reinforcement layer and improved elastic additives in the release layer. When the ambient temperature decreases, the elastic additives maintain the flexibility and elasticity of the coating, preventing the molecular motion from tending to stop, which would cause the coating to stiffen and the surface energy to drop too quickly. This ensures that the self-adhesive layer is in full contact with it, avoiding the tendency to form small air gaps and amplify separation. The flexible support of the first and second buffer layers is linked with the nanofiller of the heat-stabilized layer to further prevent poor adhesion or automatic lifting, which would cause the bonding interface to fail immediately under slight vibration or stress. Combined with the preparation method, the plasma surface treatment, vacuum hot pressing composite and precision roller coating process ensure that each layer is tightly bonded and the coating is uniform, improving the overall stability of the film and production efficiency. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a flowchart illustrating the preparation process of the present invention. Detailed Implementation
[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.
[0020] Please see Figure 1 , Figure 2A low-adhesion self-adhesive release film includes: a substrate layer, a first buffer layer, a heat-stabilized layer, a second buffer layer, an elastic reinforcing layer, and an improved release layer. The substrate layer uses a polyester film as a support structure to provide mechanical strength and dimensional stability. The first buffer layer is disposed on the substrate layer and is tightly bonded to the substrate layer via hot-pressing to initially absorb thermal stress. The heat-stabilized layer is disposed on the first buffer layer and is uniformly bonded to the surface of the first buffer layer via a coating process. It contains heat stabilizers and nanofillers to buffer the effects of temperature changes on molecular motion. The second buffer layer is disposed on the heat-stabilized layer and is bonded to the substrate layer via hot-pressing. The stabilizing layer is tightly bonded to further isolate thermal stress and enhance interlayer adhesion. An elastic reinforcing layer is coated onto the second buffer layer and uniformly bonded to its surface via a roll coating process. Containing elastic additives, it improves the coating's flexibility at low temperatures. An improved release layer is coated onto the elastic reinforcing layer and uniformly bonded to its surface via a roll coating process. A silicon-based coating incorporates temperature-responsive polymers and elastic additives to achieve low-tack adhesion and peel strength. The substrate layer is specifically made of polyethylene terephthalate (PET) film with a thickness of 20μm-100μm, providing high tensile strength and thermal stability. The first buffer layer is made of polyimide (PI) film with a thickness of 5μm-15μm, bonded to the substrate layer via a hot-press lamination process at a temperature of 300°C-350°C and a pressure of 2MPa-5MPa to absorb initial thermal stress and improve interlayer adhesion. The heat-stabilized layer contains benzotriazole heat stabilizers and silica nanofillers, with the heat stabilizer content ranging from 1wt% to 5wt% and the nanofiller particle size ranging from 10nm to 50nm. After being dispersed in a solvent, it is coated onto the first buffer layer and then thermo-cured at 150°C to 200°C to form a stable layer with a thickness of 5μm to 20μm. The second buffer layer is made of polyurethane (PU) film with a thickness of 5μm to 10μm. It is bonded to the heat-stabilized layer through a hot-pressing composite process at a temperature of 250°C to 300°C and a pressure of 1MPa to 3MPa to further isolate thermal stress and enhance the interlayer bonding strength. The elastic reinforcing layer is a mixture of polyurethane elastomer and nitrile rubber (NBR) with a mixing ratio of 3:1 to 5:1 and a coating thickness of 3μm to 8μm. It is bonded to the second buffer layer through a roller coating process and then dried and cured at 120°C to 150°C to improve the coating flexibility at low temperatures.The improved release layer uses polydimethylsiloxane (PDMS) as the silicone-based coating matrix, incorporating poly(N-isopropylacrylamide) (PNIPAM) as a temperature-responsive polymer and polyurethane elastomer as an elastic additive. The temperature-responsive polymer content is 2wt%-10wt%, and the elastic additive content is 1wt%-8wt%. After mixing and stirring, it is roller-coated onto the elastic reinforcement layer and cured under UV light to form a release layer with a thickness of 1μm-10μm. The improved release film utilizes the temperature-responsive polymer in the release layer. When the external temperature rises, this polymer, through a dynamic cross-linking network, inhibits intensified molecular motion, preventing thermal energy from causing increased intermolecular spacing and vibrational acceleration, thereby stabilizing surface energy and preventing the amplification of van der Waals forces and hydrogen bonds between interfacial molecules, which would otherwise increase interfacial forces. The heat stabilizer and nanofiller in the heat-stabilized layer work in conjunction with the thermal stress absorption functions of the first and second buffer layers to further reduce film tensile deformation and rupture caused by increased peel force, maintaining film integrity and preventing residual debris from contaminating the substrate surface. The improved release film, through the elastic reinforcement layer and the improved release layer… The elastic additives in the layer maintain the flexibility and elasticity of the coating when the ambient temperature decreases, preventing the molecular motion from becoming static, which would cause the coating to stiffen and the surface energy to drop too quickly. This ensures sufficient contact between the self-adhesive layer and the coating, avoiding the formation of tiny air gaps that amplify the tendency to separate. The flexible support of the first and second buffer layers, in conjunction with the nanofillers in the heat-stabilized layer, further prevents poor adhesion or automatic peeling, which would cause the bonding interface to fail immediately under slight vibration or stress. The improved release film adopts a six-layer composite structure design. Through the multi-level buffering of the first buffer layer, the heat-stabilized layer, the second buffer layer, and the elastic reinforcement layer, and the linkage of the improved release layer, when the temperature changes, the first and second buffer layers absorb thermal stress, the heat-stabilized layer stabilizes the molecular structure, and the elastic reinforcement layer improves low-temperature flexibility. Overall, it prevents the surface energy fluctuation from amplifying the changes in interfacial forces, thereby reducing peeling difficulties and deformation at high temperatures and avoiding insufficient contact and peeling at low temperatures. The synergistic effect of the six-layer structure further solves the overall instability caused by temperature sensitivity, reduces bonding misalignment and automatic peeling during production, and improves the reliability and environmental resistance of the bonding system.
[0021] A method for preparing a low-viscosity self-adhesive release film further includes the following preparation method: Step 1: Prepare the substrate layer. Select polyethylene terephthalate (PET) film as the substrate layer with a thickness of 20μm-100μm, and ensure that its surface is clean and free of impurities. Step 2: Add the first buffer layer. Place the polyimide (PI) film on the substrate layer and laminate it using a hot-pressing process at a temperature of 300°C-350°C and a pressure of 2MPa-5MPa to form a first buffer layer with a thickness of 5μm-15μm, which is used to absorb initial thermal stress and improve interlayer adhesion. Step 3: Add a heat-stabilized layer. Disperse benzotriazole heat stabilizer (1wt%-5wt%) and silica nanofiller (10nm-50nm particle size) in a solvent and coat them onto the surface of the first buffer layer. Then, heat-cure at 150°C-200°C to form a heat-stabilized layer with a thickness of 5μm-20μm, which is used to buffer the effect of temperature changes on molecular motion. Step 4: Add a second buffer layer. Place the polyurethane (PU) film on the heat-stabilized layer and laminate it using a hot-pressing process at a temperature of 250°C-300°C and a pressure of 1MPa-3MPa to form a second buffer layer with a thickness of 5μm-10μm, which is used to further isolate thermal stress and enhance the interlayer bonding strength. Step 5: Add an elastic reinforcement layer. Mix polyurethane elastomer and nitrile rubber (NBR) at a ratio of 3:1 to 5:1, apply the mixture to the surface of the second buffer layer using a roller coating process, and dry and cure at 120°C-150°C to form an elastic reinforcement layer with a thickness of 3μm-8μm, which is used to improve the flexibility of the coating at low temperatures. Step Six: Add an improved release layer. Polydimethylsiloxane (PDMS) is used as the silicone-based coating matrix. 2 wt%-10 wt% of poly(N-isopropylacrylamide) (PNIPAM) is incorporated as a temperature-responsive polymer, and 1 wt%-8 wt% of polyurethane elastomer is incorporated as an elastic additive. After mixing and stirring, the mixture is roller-coated onto the surface of the elastic reinforcement layer and cured under UV light to form an improved release layer with a thickness of 1 μm-10 μm, thereby achieving low-tack adhesion and peeling functions.
[0022] In step one, the polyethylene terephthalate (PET) film undergoes plasma surface treatment before preparation to improve surface roughness and adhesion, ensuring a tight bond between the first buffer layer and the substrate layer. In step three, the solvent dispersion of the heat-stabilizing layer uses a 1:1 volume ratio of ethanol and water. The coating is performed using a doctor blade coating method at a speed controlled between 0.5 m / min and 2 m / min to ensure uniform distribution of the heat stabilizer and nanofillers. In step four, the hot-pressing lamination process of the second buffer layer is carried out under vacuum conditions (0.01 MPa-0.05 MPa) to reduce bubble formation and improve the bonding strength between the polyurethane (PU) film and the heat-stabilizing layer. In step five, 1 wt%-3 wt% of a silane coupling agent is added to the mixture of polyurethane elastomer and nitrile rubber (NBR) before mixing to enhance the compatibility of the mixture and the adhesion between the coating and the second buffer layer. In step six, the improved release layer roll coating process uses a two-roller coater, with the roll coating temperature controlled between 25°C and 40°C and the roll coating speed between 1 m / min and 3 m / min to ensure uniform coating thickness and surface smoothness. In step six, UV curing uses 365 nm wavelength UV light, with a curing time of 30-60 seconds and a UV light intensity of 100 mW / cm².2 -200mW / cm 2 This is to ensure the rapid curing of the improved release layer and the stability of the molecular cross-linking structure.
[0023] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
Claims
1. A low-tack self-adhesive release film, characterized in that: include: The substrate layer, the first buffer layer, the heat-stabilized layer, the second buffer layer, the elastic reinforcement layer, and the improved release layer; The substrate layer uses a polyester film as a support structure to provide mechanical strength and dimensional stability. The first buffer layer is disposed on the substrate layer and is tightly bonded to the substrate layer by hot-pressing to initially absorb thermal stress. The heat-stabilizing layer is disposed on the first buffer layer and is uniformly bonded to the surface of the first buffer layer by a coating process. It contains heat stabilizers and nanofillers to buffer the influence of temperature changes on molecular motion. The second buffer layer is disposed on the heat-stabilizing layer and is tightly bonded to the heat-stabilizing layer by hot-pressing to further isolate thermal stress and enhance interlayer bonding. The elastic reinforcing layer is coated on the second buffer layer and is uniformly bonded to the surface of the second buffer layer by a roll coating process. It contains elastic additives to improve the flexibility of the coating at low temperatures. The improved release layer is coated on the elastic reinforcing layer and is uniformly bonded to the surface of the elastic reinforcing layer by a roll coating process. It uses a silicon-based coating incorporating temperature-responsive polymers and elastic additives.
2. The low-tack self-adhesive release film according to claim 1, wherein: The substrate layer is specifically made of polyethylene terephthalate (PET) film with a thickness of 20μm-100μm, providing high tensile strength and thermal stability.
3. The low-tack self-adhesive release film according to claim 1, wherein: The first buffer layer is made of polyimide (PI) film with a thickness of 5μm-15μm. It is bonded to the substrate layer by hot-pressing composite process at a temperature of 300°C-350°C and a pressure of 2MPa-5MPa to absorb initial thermal stress and improve interlayer adhesion.
4. The low-tack self-adhesive release film according to claim 1, wherein: The heat-stabilized layer contains a benzotriazole heat stabilizer and silica nanofiller. The heat stabilizer content is 1wt%-5wt%, and the nanofiller particle size is 10nm-50nm. After being dispersed in a solvent, it is coated onto the first buffer layer and thermo-cured at 150°C-200°C to form a stable layer with a thickness of 5μm-20μm. The second buffer layer is a polyurethane (PU) film with a thickness of 5μm-10μm. It is bonded to the heat-stabilized layer through a hot-pressing composite process at a temperature of 250°C-300°C and a pressure of 1MPa-3MPa to further isolate thermal stress and enhance the interlayer bonding strength. The elastic reinforcing layer is a mixture of polyurethane elastomer and nitrile rubber (NBR) with a mixing ratio of 3:1 to 5:1 and a coating thickness of 3μm-8μm. It is bonded to the second buffer layer through a roller coating process and dried and cured at 120°C-150°C to improve the coating flexibility at low temperatures.
5. The low-tack self-adhesive release film according to claim 1, characterized in that: The improved release layer uses polydimethylsiloxane (PDMS) as the silicone-based coating matrix, incorporating poly(N-isopropylacrylamide) (PNIPAM) as a temperature-responsive polymer and polyurethane elastomer as an elastic additive. The temperature-responsive polymer content is 2wt%-10wt%, and the elastic additive content is 1wt%-8wt%. After mixing and stirring, the mixture is roller-coated onto the elastic reinforcement layer and then UV-cured to form a release layer with a thickness of 1μm-10μm. The improved release film utilizes the temperature-responsive polymer in the improved release layer, the heat stabilizer in the heat-stabilizing layer, and the nanofillers. The thermal stress absorption functions of the first and second buffer layers are linked. The improved release film, through the elastic reinforcement layer and the elastic additives in the improved release layer, the flexible support of the first and second buffer layers is linked with the nanofiller of the thermal stability layer. The improved release film adopts a six-layer composite structure design. Through the multi-level buffering of the first buffer layer, thermal stability layer, second buffer layer and elastic reinforcement layer and the linkage of the improved release layer, when the temperature changes, the first and second buffer layers absorb thermal stress, the thermal stability layer stabilizes the molecular structure, and the elastic reinforcement layer improves low-temperature flexibility.
6. A method of making a low-tack self-adhesive release film, characterized by: The low-viscosity self-adhesive release film applied to any one of claims 1-5 further includes the following preparation method: Step 1: Prepare the substrate layer. Select polyethylene terephthalate (PET) film as the substrate layer with a thickness of 20μm-100μm, and ensure that its surface is clean and free of impurities. Step 2: Add the first buffer layer. Place the polyimide (PI) film on the substrate layer and laminate it using a hot-pressing process at a temperature of 300°C-350°C and a pressure of 2MPa-5MPa to form a first buffer layer with a thickness of 5μm-15μm. Step 3: Add a heat-stabilized layer. Disperse benzotriazole heat stabilizer (1wt%-5wt%) and silica nanofiller (10nm-50nm particle size) in a solvent and coat them onto the surface of the first buffer layer. Then, heat-cure at 150°C-200°C to form a heat-stabilized layer with a thickness of 5μm-20μm. Step 4: Add a second buffer layer. Place the polyurethane (PU) film on the heat-stabilized layer and laminate it using a hot-pressing process at a temperature of 250°C-300°C and a pressure of 1MPa-3MPa to form a second buffer layer with a thickness of 5μm-10μm. Step 5: Add an elastic reinforcement layer. Mix polyurethane elastomer and nitrile rubber (NBR) at a mixing ratio of 3:1 to 5:1, apply the mixture to the surface of the second buffer layer using a roller coating process, and dry and cure at 120°C-150°C to form an elastic reinforcement layer with a thickness of 3μm-8μm. Step Six: Add an improved release layer. Polydimethylsiloxane (PDMS) is used as the silicone-based coating matrix. Poly(N-isopropylacrylamide) (PNIPAM) with a content of 2wt%-10wt% is incorporated as a temperature-responsive polymer, and polyurethane elastomer with a content of 1wt%-8wt% is incorporated as an elastic additive. After mixing and stirring, the mixture is roller-coated onto the surface of the elastic reinforcement layer and cured under ultraviolet light to form an improved release layer with a thickness of 1μm-10μm.
7. The method for preparing a low-viscosity self-adhesive release film according to claim 6, characterized in that: In step one, the polyethylene terephthalate (PET) film undergoes plasma surface treatment before preparation to improve surface roughness and adhesion, ensuring a tight bond between the first buffer layer and the substrate layer. In step three, the solvent dispersion of the heat-stabilizing layer uses a mixture of ethanol and water in a 1:1 volume ratio. During coating, a doctor blade coating method is used, and the coating speed is controlled at 0.5 m / min-2 m / min to ensure the uniform distribution of the heat stabilizer and nanofiller.
8. The method for preparing a low-viscosity self-adhesive release film according to claim 6, characterized in that: In step four, the hot-pressing composite process of the second buffer layer is carried out in a vacuum environment with a vacuum degree of 0.01MPa-0.05MPa. In step five, 1wt%-3wt% of silane coupling agent is added to the mixture of polyurethane elastomer and nitrile rubber (NBR) before mixing.
9. The method for preparing a low-viscosity self-adhesive release film according to claim 6, characterized in that: In step six, the improved release layer is coated using a two-roller coater, with the coating temperature controlled at 25°C-40°C and the coating speed at 1m / min-3m / min.
10. The method for preparing a low-viscosity self-adhesive release film according to claim 6, characterized in that: In step six, the ultraviolet curing uses ultraviolet light with a wavelength of 365nm, a curing time of 30s-60s, and an ultraviolet light intensity of 100mW / cm². 2 -200mW / cm 2 .