Viscosity-reducing protective film

Abstract

The visbreaking protective film comprises a base material layer, a functional light-transmitting layer and a visbreaking layer, the functional light-transmitting layer is arranged between the base material layer and the visbreaking layer, the functional light-transmitting layer contains a thermochromic material, the thermochromic material is used for changing the light transmittance of the film under the condition of changing the temperature, and the visbreaking layer can reduce the viscosity under the action of illumination. The viscosity-reducing protective film provided by the invention can be exposed for a long time under illumination without causing viscosity reduction, and has relatively high reliability.

Description

Technical Field

[0001] The present application relates to the field of membrane material technology, and in particular to a viscosity-reducing protective film. Background Art

[0002] At present, the structure of common anti-viscosity protective films is mainly composed of a substrate and an anti-viscosity adhesive layer, wherein the substrate has functional functions such as isolation protection, waterproof and dustproof, tear resistance, high temperature resistance or corrosion resistance, and a photoinitiator is added to the anti-viscosity adhesive layer. After irradiating the anti-viscosity protective film attached to the substrate with UV light, the viscosity of the anti-viscosity adhesive layer decreases, so that the anti-viscosity protective film can be quickly removed from the substrate.

[0003] However, the existing anti-viscosity protective film has unstable viscosity, is easy to fall off, and has poor protective effect. Summary of the invention

[0004] In view of this, in order to solve at least one of the above technical problems, an embodiment of the present application provides a new type of viscosity-reducing protective film.

[0005] An embodiment of the present application provides a viscosity-reducing protective film, which includes: a substrate layer, a functional light-transmitting layer and a viscosity-reducing layer, wherein the functional light-transmitting layer is arranged between the substrate layer and the viscosity-reducing layer, the functional light-transmitting layer contains a thermochromic material, and the thermochromic material is used to change the transmittance of the functional light-transmitting layer under the condition of changing the temperature, and the viscosity-reducing layer can reduce the viscosity under the action of light.

[0006] In some possible embodiments, the mass percentage of the thermochromic material in the viscosity-reducing protective film is 1 wt % to 15 wt %.

[0007] In some possible embodiments, the thermochromic material includes a plurality of thermochromic capsules, each of the thermochromic capsules includes a core material and a wall material located on a surface of the core material, and the wall material is made of urea-formaldehyde resin or epoxy resin.

[0008] In some possible embodiments, the thickness of the wall material is 1 μm to 20 μm.

[0009] In some possible embodiments, the particle size of the core material is 0.5 μm to 15 μm.

[0010] In some possible embodiments, the core material includes a thermosensitive dye, a solvent, and a developer.

[0011] In some possible embodiments, the mass ratio of the thermosensitive dye, the solvent and the developer is (0.1-10): (20-80): (1-15).

[0012] In some possible embodiments, the thermosensitive dye includes at least one of 1,3-dimethyl-6-diethylaminofluoran, 1,2-benzo-6-diethylaminofluoran, 3,6-dimethoxyfluoran, 2-phenylamino-3-methyl-6-dibutylaminofluoran and 3,3-bis(4-diethylamino-2-ethoxyphenyl)-4-azaphthalide.

[0013] In some possible embodiments, the solvent includes at least one of tetradecanol, hexadecanol, ethyl laurate, stearic acid and 2-(4-benzyloxyphenyl)ethyldecanoate.

[0014] In some possible embodiments, the developer includes at least one of 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4,4'-sulfonylbis[2-(2-propenyl)]phenol, 2,4-di(phenylsulfonyl)phenol and bisphenol A.

[0015] In some possible embodiments, the adhesion-reducing layer includes acrylate glue and a photoinitiator.

[0016] Compared with the prior art, the viscosity-reducing protective film provided in the embodiment of the present application, by providing a functional light-transmitting layer between the substrate layer and the viscosity-reducing layer, the functional light-transmitting layer contains a thermochromic material, which can make the transmittance of the functional light-transmitting layer change with temperature. In this way, when it is necessary to peel off the viscosity-reducing protective film, the temperature can be changed to make the functional light-transmitting layer transparent, and the viscosity of the viscosity-reducing layer can be reduced by light exposure to achieve easy peeling of the viscosity-reducing protective film. Therefore, the viscosity-reducing protective film provided in the embodiment of the present application can be exposed to light for a long time without causing a decrease in viscosity, has high reliability, and can effectively improve the protective effect of the viscosity-reducing protective film. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 A schematic diagram of the structure of a viscosity-reducing protective film provided in one embodiment of the present application.

[0018] Figure 2 This is a schematic diagram of the structure of a thermochromic capsule provided in one embodiment of the present application.

[0019] Figure 3 This is a picture of the anti-viscosity protective film in Example 3 of the present application before heating.

[0020] Figure 4 This is a picture of the anti-viscosity protective film after heating in Example 3 of the present application.

[0021] Figure 5 This is a picture of the battery slot being anodized after the viscosity-reducing protective film in Example 3 of the present application is applied to the battery slot for shielding.

[0022] Figure 6This is a picture of the battery container after the viscosity-reducing protective film in Comparative Example 1 of the present application is applied to the battery container for shielding and then the battery container is anodized. DETAILED DESCRIPTION

[0023] The following will clearly and completely describe the technical solutions in the embodiments of the present application in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments.

[0024] See also Figure 1 , the embodiment of the present application provides a viscosity-reducing protective film 100, which can be used to adhere to the surface of the protected target object to shield and protect the protected target object. The viscosity-reducing protective film 100 specifically includes: a substrate layer 10, a functional light-transmitting layer 20 and a viscosity-reducing layer 30, wherein the functional light-transmitting layer 20 is arranged between the substrate layer 10 and the viscosity-reducing layer 30. The functional light-transmitting layer 20 contains a thermochromic material, and the thermochromic material is used to change the light transmittance of the functional light-transmitting layer 20 under the condition of changing the temperature, so that the functional light-transmitting layer 20 can transmit light when needed. For example, when the temperature is increased, the thermochromic material undergoes a phase change, the functional light-transmitting layer 20 changes from a colored state to a colorless state, and the light transmittance of the functional light-transmitting layer 20 increases; when the temperature is reduced, the functional light-transmitting layer 20 is in a colored state, thereby blocking the light from passing through. Alternatively, the temperature can be lowered to cause the thermochromic material to undergo a phase change, and the functional light-transmitting layer 20 changes from a colored state to a colorless state, and the light transmittance of the functional light-transmitting layer 20 increases; when the temperature rises, the functional light-transmitting layer 20 is in a colored state, blocking the light from passing through. Through this temperature adjustment method, the functional light-transmitting layer 20 can adjust the light transmittance at different temperatures as required to achieve the purpose of controlling the light transmission. When light passes through the functional light-transmitting layer 20 and irradiates the viscosity-reducing layer 30, the viscosity-reducing layer 30 can reduce the viscosity under the action of light, thereby causing the viscosity-reducing protective film 100 to fall off or peel off from the protected target.

[0025] The substrate layer 10 is used to protect the target object and needs to have certain functionality, such as isolation protection, waterproof and dustproof, tear resistance, high temperature resistance or acid and alkali corrosion resistance. Specifically, the material of the substrate layer 10 can be at least one of polyethylene terephthalate (PET), polyolefin (PO), polyvinyl chloride (PVC) and cross-linked polyolefin (CPO). These materials have excellent mechanical strength, corrosion resistance and processability, which is conducive to the viscosity-reducing protective film 100 to provide good protection for the target object. In addition, the substrate layer 10 is generally made of a transparent material to facilitate light transmission.

[0026] Please refer to Figure 2, the thermochromic material in the functional light-transmitting layer 20 may include a plurality of thermochromic capsules 21. The thermochromic capsules 21 can increase the transmittance when the temperature rises and decrease the transmittance when the temperature drops, or increase the transmittance when the temperature drops and decrease the transmittance when the temperature rises. Specifically, each thermochromic capsule 21 may include a core material 22 and a wall material 23 located on the surface of the core material 22, wherein the core material 22 has a thermochromic function and can increase the transmittance when the temperature rises and decrease the transmittance when the temperature drops. The wall material 23 is used to protect the core material 22 to reduce the impact of external factors on the core material 22.

[0027] The core material 22 includes a thermosensitive dye, a solvent, and a color developer. When the viscosity-reducing protective film 100 is heated to a certain temperature, about 50°C to 80°C, the solvent in the core material 22 melts due to the heat, and the color developer can dissociate protons (H + ), thereby causing the conjugated system of the thermosensitive dye to change, so that the functional light-transmitting layer 20 changes from a colored state to a colorless and transparent state, thereby achieving a change in transmittance from low to high.

[0028] In some embodiments, the thermosensitive dye may include at least one of 1,3-dimethyl-6-diethylaminofluoran (D-5), 1,2-benzo-6-diethylaminofluoran (BL-502), 3,6-dimethoxyfluoran (Y-1), 2-phenylamino-3-methyl-6-dibutylaminofluoran (ODB-2), and 3,3-bis(4-diethylamino-2-ethoxyphenyl)-4-azaphthalide (GN-2). The above thermosensitive materials can all undergo molecular structure changes upon protonation, causing color changes.

[0029] Illustratively, as shown in the following procedure, the thermosensitive dye may have a lactone structure, and the lactone structure undergoes a reversible change in molecular structure upon protonation to form a quinone structure, thereby causing a color change.

[0030] In some embodiments, the solvent may include at least one of tetradecanol, hexadecanol, ethyl laurate, stearic acid, 2-(4-benzyloxyphenyl)ethyldecanoate, and the like.

[0031] In some embodiments, the developer may include at least one of 4-hydroxy-4′-isopropoxydiphenyl sulfone (D-8), 4,4′-sulfonylbis[2-(2-propenyl)]phenol (TGSH), 2,4-di(phenylsulfonyl)phenol (DBSP), bisphenol A, and the like.

[0032] In some embodiments, the mass ratio of the thermosensitive dye, the solvent, and the developer can be (0.1-10): (20-80): (1-15). The mass ratio in the above range is conducive to the thermosensitive dye, the solvent, and the developer to exert a better synergistic effect, which helps to improve the color change response temperature range, color change speed, and color change visibility of the viscosity-reducing protective film 100. The mass ratio of the thermosensitive dye, the solvent, and the developer can further be (1-3): (25-40): (2-5).

[0033] In some embodiments, the particle size of the core material 22 can be 0.5 μm to 15 μm, and further can be 2 μm to 10 μm. For example, it can be 0.5 μm, 1 μm, 3 μm, 5 μm, 8 μm, 10 μm, 15 μm or any value within the numerical range formed by any two of the above values.

[0034] The material of the wall material 23 can be at least one of urea-formaldehyde resin and epoxy resin, etc. The above materials are conducive to improving the mechanical strength of the wall material 23, forming a capsule structure on the outer layer of the core material 22 to provide strong protection, and effectively reduce the risk of damage or rupture of the thermochromic capsule 21 during use.

[0035] In some embodiments, the thickness of the wall material 23 may be 1 μm to 20 μm, which is beneficial to further improve the protection effect of the core material 22. The thickness of the wall material 23 may further be 5 μm to 15 μm, and may be 1 μm, 3 μm, 5 μm, 8 μm, 10 μm, 15 μm, 18 μm, 20 μm or any value within the numerical range formed by any two of the above values.

[0036] The mass percentage of the thermochromic material in the viscosity-reducing protective film 100 may be 1 wt% to 15 wt%, which is beneficial to balance the protective effect, viscosity-reducing effect and discoloration effect of the viscosity-reducing protective film 100. The mass percentage of the thermochromic material in the viscosity-reducing protective film 100 may further be 4 wt% to 12 wt%, and may be 1 wt%, 2 wt%, 3 wt%, 4 wt%, 5.7 wt%, 6.3 wt%, 8.6 wt%, 9.5 wt%, 10 wt%, 11.5 wt%, 12 wt%, 13 wt%, 14 wt%, 15 wt% or any value within the numerical range consisting of any two of the above values.

[0037] Please refer again Figure 1 The functional light-transmitting layer 20 also contains an adhesive, which is beneficial to the connection between the functional light-transmitting layer 20 and the substrate layer 10 and the viscosity-reducing layer 30, and plays a role in protecting the thermochromic material.

[0038] In some embodiments, the adhesive may include at least one of natural rubber, synthetic rubber, silicone, and the like.

[0039] Please refer again Figure 1 The viscosity-reducing layer 30 includes an acrylate glue and a photoinitiator. When the light transmittance of the functional light-transmitting layer 20 increases, the photoinitiator (M) absorbs photons (hv) in the light after being illuminated to form an excited state (M*): M+hv→M*. The excited active molecules (M*) undergo homolytic cleavage to generate free radicals: M*→R·+R·', and open the double bonds contained in the acrylate glue. Free radical polymerization occurs between the double bonds and they are highly cross-linked with each other, thereby initiating monomer polymerization to generate a polymer. After being highly cross-linked, the viscosity-reducing layer 30 shrinks in volume, the cohesive force increases, the glue surface becomes hard, and the surface viscosity decreases, thereby achieving a viscosity-reducing effect. It is understandable that other photoinitiators and glues can also be used, and any photoinitiator and glue that can reduce the viscosity of the viscosity-reducing layer 30 under the action of light can be used.

[0040] Specifically, the viscosity-reducing protective film 100 can be adhered to the protected object through the viscosity-reducing layer 30. At room temperature (about 20°C to 30°C), due to the presence of the thermochromic material, the viscosity-reducing protective film 100 is colored, and the light transmittance of the viscosity-reducing protective film 100 is low, so that even if the viscosity-reducing protective film 100 is exposed to light for a long time, a large amount of light will not penetrate the functional light-transmitting layer 20 to the viscosity-reducing layer 30, causing the viscosity to decrease and cause the viscosity-reducing protective film 100 to fail or the viscosity-reducing protective film 100 adhered to the protected object to fall off, thereby improving the reliability of the viscosity-reducing protective film 100. When it is necessary to remove the viscosity-reducing protective film 100 from the protected object, the thermochromic material needs to be discolored by adjusting the temperature (increasing or decreasing the temperature), and the viscosity-reducing protective film 100 changes from colored to colorless, and the light transmittance of the viscosity-reducing protective film 100 increases accordingly. At the same time, by combining light, such as ultraviolet (UV) irradiation, etc., the viscosity of the viscosity-reducing layer 30 is reduced, and the viscosity-reducing protective film 100 can be easily peeled off from the protected object without causing deformation or damage to the protected object.

[0041] The specific process of removing the viscosity-reducing protective film 100 is as follows: the viscosity-reducing protective film 100 is subjected to temperature change treatment (heating or cooling) and light irradiation treatment. The heating and light irradiation can be performed simultaneously, or the heating can be performed first and then the light irradiation.

[0042] Among them, the heating treatment includes: using heating methods such as thermal radiation to heat the anti-viscosity protective film 100 until the surface temperature of the anti-viscosity protective film 100 is 50°C~80°C, the color of the functional light-transmitting layer 20 changes from colored to colorless, and the light transmittance increases, so that the anti-viscosity layer 30 can receive light. It can be understood that the heating method includes but is not limited to thermal radiation, and any method that can perform heating and temperature raising treatment is acceptable.

[0043] The cooling process includes but is not limited to convection and other methods.

[0044] Among them, the light treatment can include using a light source such as ultraviolet light, visible light (red light, green light, etc.), infrared light or LED light source to irradiate the anti-viscosity protective film 100. The photoinitiator in the anti-viscosity layer 30 absorbs photons to form an excited state, and splits to produce free radicals, causing the acrylate glue to be highly cross-linked, thereby hardening the anti-viscosity layer 30 and reducing the surface adhesion, achieving a anti-viscosity effect, and can be easily peeled off.

[0045] Furthermore, heating and illumination can be performed simultaneously through ultraviolet radiation, which can not only provide an irradiation light source, but also increase the temperature of the thermal viscosity-reducing protective film 100 through a photothermal effect, thereby making the operation more convenient.

[0046] Exemplarily, the anti-viscosity protective film 100 can be affixed to the surface of a battery container for protection during the preparation process of the battery container. Since the anti-viscosity protective film 100 will not fall off the surface of the battery container due to exposure to light, and can be easily peeled off by heating and light when necessary, it can effectively reduce surface damage to the battery container and anode seepage during the production and preparation process, thereby improving the production yield of the battery container.

[0047] Compared with the prior art, the anti-viscosity protective film 100 provided in the embodiment of the present application has the following beneficial effects: 1. Since the functional light-transmitting layer 20 contains thermochromic materials, when there is no need to peel off the viscosity-reducing protective film 100, the functional light-transmitting layer 20 remains colored, so that light cannot pass through the functional light-transmitting layer 20 to cause the viscosity of the viscosity-reducing layer 30 to change, so that the viscosity-reducing protective film 100 will not fail or fall off due to exposure to light.

[0048] 2. Under the condition of changing the temperature, adjust the light transmittance of the functional light-transmitting layer 20. When the light transmittance of the functional light-transmitting layer 20 is increased, the viscosity-reducing protective film 100 that can reduce the viscosity under the action of light is irradiated, and the viscosity of the viscosity-reducing layer 30 will decrease or even disappear, and it can be easily peeled off, reducing the deformation of the protected target caused by direct film tearing.

[0049] 3. The anti-viscosity protective film 100 has a simple design, low cost, and is easy to operate. It can be mass-produced and applied to protected objects such as battery containers to improve the safety and stability of the protected objects during production, transportation, storage, or use.

[0050] The above-mentioned viscosity-reducing protective film is further described below through specific examples.

[0051] Example 1 A viscosity-reducing protective film comprises a substrate layer, a functional light-transmitting layer and a viscosity-reducing layer, wherein the functional light-transmitting layer is arranged between the substrate layer and the viscosity-reducing layer, wherein the substrate layer comprises PET; the functional light-transmitting layer comprises a binder natural rubber and a thermochromic material, the mass ratio of the thermochromic material to the viscosity-reducing protective film is 5.7wt%, the thermochromic material comprises a plurality of thermochromic capsules, each of the thermochromic capsules has a wall material and a core material made of urea-formaldehyde resin, the thermosensitive dye in the core material is BL-502, the solvent is ethyl laurate and 2-(4-benzyloxyphenyl)ethyldecanoate, the color developer is bisphenol A, and the mass ratio of the thermosensitive material, the solvent and the color developer in the core material is 1:25:2; the viscosity-reducing layer comprises an acrylate glue and a photoinitiator, and can reduce the viscosity under the action of light.

[0052] Example 2 A viscosity-reducing protective film comprises a substrate layer, a functional light-transmitting layer and a viscosity-reducing layer, wherein the functional light-transmitting layer is arranged between the substrate layer and the viscosity-reducing layer, wherein the substrate layer comprises PET; the functional light-transmitting layer comprises a binder natural rubber and a thermochromic material, the mass ratio of the thermochromic material to the viscosity-reducing protective film is 9.5wt%, the thermochromic material comprises a plurality of thermochromic capsules, each of the thermochromic capsules has a wall material and a core material made of urea-formaldehyde resin, the thermosensitive dye in the core material is Y-1, the solvent is 2-(4-benzyloxyphenyl)ethyldecanoate, the color developer is TGSH, and the mass ratio of the thermosensitive material, the solvent and the color developer in the core material is 1:28:3; the viscosity-reducing layer comprises an acrylate glue and a photoinitiator, and can reduce the viscosity under the action of light.

[0053] Example 3 A viscosity-reducing protective film comprises a substrate layer, a functional light-transmitting layer and a viscosity-reducing layer, wherein the functional light-transmitting layer is arranged between the substrate layer and the viscosity-reducing layer, wherein the substrate layer comprises PO; the functional light-transmitting layer comprises an adhesive silica gel and a thermochromic material, wherein the mass ratio of the thermochromic material to the viscosity-reducing protective film is 6.3wt%, and the thermochromic material comprises a plurality of thermochromic capsules, each of which has a wall material and a core material made of epoxy resin, wherein the thermosensitive dyes in the core material are ODB-2 and BL-502, the solvents are tetradecanol and ethyl laurate, the color developer is bisphenol A, and the mass ratio of the thermosensitive material, the solvent and the color developer in the core material is 2:35:2; the viscosity-reducing layer comprises an acrylate glue and a photoinitiator, and can reduce the viscosity under the action of light.

[0054] Example 4 A viscosity-reducing protective film comprises a substrate layer, a functional light-transmitting layer and a viscosity-reducing layer, wherein the functional light-transmitting layer is arranged between the substrate layer and the viscosity-reducing layer, wherein the substrate layer comprises CPO; the functional light-transmitting layer comprises a binder synthetic rubber and a thermochromic material, wherein the mass ratio of the thermochromic material to the viscosity-reducing protective film is 10wt%, and the thermochromic material comprises a plurality of thermochromic capsules, each of which has a wall material and a core material made of urea-formaldehyde resin, wherein the thermosensitive dye in the core material is D-5, the solvent is hexadecanol and 2-(4-benzyloxyphenyl)ethyldecanoate, the color developer is TGSH and DBSP, and the mass ratio of the thermosensitive material, the solvent and the color developer in the core material is 3:30:4; the viscosity-reducing layer comprises an acrylate glue and a photoinitiator, and can reduce the viscosity under the action of light.

[0055] Example 5 A viscosity-reducing protective film comprises a substrate layer, a functional light-transmitting layer and a viscosity-reducing layer, wherein the functional light-transmitting layer is arranged between the substrate layer and the viscosity-reducing layer, wherein the substrate layer comprises PO; the functional light-transmitting layer comprises an adhesive silica gel and a thermochromic material, wherein the mass ratio of the thermochromic material to the viscosity-reducing protective film is 1wt%, and the thermochromic material comprises a plurality of thermochromic capsules, each of which has a wall material and a core material made of urea-formaldehyde resin, wherein the thermosensitive dyes in the core material are BL-502 and D-5, the solvents are tetradecanol and 2-(4-benzyloxyphenyl)ethyldecanoate, the color developer is bisphenol A, and the mass ratio of the thermosensitive material, the solvent and the color developer in the core material is 1.5:32:2.5; the viscosity-reducing layer comprises an acrylate glue and a photoinitiator, and can reduce the viscosity under the action of light.

[0056] Example 6 A viscosity-reducing protective film comprises a substrate layer, a functional light-transmitting layer and a viscosity-reducing layer, wherein the functional light-transmitting layer is arranged between the substrate layer and the viscosity-reducing layer, wherein the substrate layer comprises PET; the functional light-transmitting layer comprises an adhesive silica gel and a thermochromic material, the mass ratio of the thermochromic material to the viscosity-reducing protective film is 15wt%, the thermochromic material comprises a plurality of thermochromic capsules, each of the thermochromic capsules has a wall material and a core material made of epoxy resin, the thermosensitive dyes in the core material are ODB-2, Y-1 and BL-502, the solvent is 2-(4-benzyloxyphenyl)ethyldecanoate and ethyl laurate, the color developer is TGSH, and the mass ratio of the thermosensitive material, the solvent and the color developer in the core material is 2.5:37:4.5; the viscosity-reducing layer comprises an acrylate glue and a photoinitiator, and can reduce the viscosity under the action of light.

[0057] Comparative Example 1 A viscosity-reducing protective film comprises a substrate layer and a viscosity-reducing layer, wherein the substrate layer comprises polyurethane (PU); the viscosity-reducing layer comprises acrylate glue and a photoinitiator, and can reduce viscosity under the action of light.

[0058] Comparative Example 2 A viscosity-reducing protective film comprises a substrate layer and a viscosity-reducing layer, wherein the substrate layer comprises TPU; the viscosity-reducing layer comprises acrylate glue and a photoinitiator, and can reduce viscosity under the action of light.

[0059] The viscosity-reducing protective films in the above Examples 1-6 and Comparative Examples 1-2 were tested for light transmittance and viscosity. The viscosity-reducing protective films were applied to the battery container to perform a battery container yield test. The results are shown in Table 1.

[0060] (I) Transmittance test method: Use ultraviolet light source to irradiate the anti-viscosity protective film. The sensor of the transmittance meter detects the incident light intensity of the light source and the light intensity after passing through the anti-viscosity protective film. The ratio of the transmitted light intensity to the incident light intensity is the transmittance.

[0061] (II) Adhesion test method: refer to the 180° peel test method for single-layer coated tape, and stick the anti-viscosity protective film to the test steel plate by rolling it back and forth with a 4.5lb roller. The test can be carried out after it is left to stand. The steel plate is fixed to the lower fixture, and the sample is folded 180° and fixed to the upper fixture. The anti-viscosity protective film is peeled off from the steel plate at a speed of 300mm / min, and the average peeling force during the tearing process is measured.

[0062] (III) Battery tray yield test: Stick the anti-viscosity protective film on the surface of the battery tray, perform sandblasting, cleaning, package inspection, anode treatment, visual inspection, and film tearing, and measure the distance from the edge of the battery tray to the deepest anode seepage. The product with a seepage distance of less than 1mm is a good product. The yield is the ratio of good products per 100 pieces.

[0063] The above results show: Combining Table 1 and Figure 3-6 Compared with Comparative Example 1-2, the anti-viscosity protective film with a functional light-transmitting layer in Example 1-6 has a low light transmittance before heating, and the light transmittance is less than 40%, so that the anti-viscosity protective film can be exposed to the light environment for a long time without reducing the viscosity; the light transmittance is improved after heating, and the light transmittance is greater than 80%, and it can be easily peeled off after the viscosity is reduced by ultraviolet light, which can effectively protect the battery slot and improve the yield of the battery slot. However, since Comparative Example 1-2 does not have a functional light-transmitting layer, the light transmittance before and after heating is almost unchanged, resulting in a decrease in the viscosity of the anti-viscosity protective film during the process, resulting in a poor shielding protection effect on the battery slot, resulting in a decrease in the yield of the battery slot in the shielding process.

[0064] Therefore, in the embodiment of the present application, a functional light-transmitting layer is provided between the substrate layer and the viscosity-reducing layer, and the light transmittance of the functional light-transmitting layer changes with temperature. When it is necessary to peel off the viscosity-reducing protective film, the temperature can be changed to make the functional light-transmitting layer transparent, and the viscosity-reducing layer can be reduced in viscosity by illumination, so as to realize easy peeling of the viscosity-reducing protective film. Thus, the viscosity-reducing protective film can be exposed to light for a long time without causing a decrease in viscosity, has high reliability, and can effectively improve the protective effect of the viscosity-reducing protective film.

[0065] The description of the above embodiments is only used to help understand the method of the present application and its core idea; in addition, for ordinary technicians in this field, various other corresponding changes and deformations can be made according to the technical concept of the present application, and all these changes and deformations should fall within the scope of protection of the claims of the present application.

Claims

1. A viscosity-reducing protective film, characterized in that: The anti-viscosity protective film includes a substrate layer, a functional light-transmitting layer and an anti-viscosity layer, wherein the functional light-transmitting layer is arranged between the substrate layer and the anti-viscosity layer, the functional light-transmitting layer contains a thermochromic material, and the thermochromic material is used to change the transmittance of the functional light-transmitting layer under the condition of changing the temperature, and the anti-viscosity layer can reduce the viscosity under the action of light.

2. The anti-viscosity protective film according to claim 1, characterized in that: The mass percentage of the thermochromic material in the viscosity-reducing protective film is 1wt% to 15wt%.

3. The viscosity-reducing protective film according to claim 1, characterized in that: The thermochromic material includes a plurality of thermochromic capsules, each of which includes a core material and a wall material located on the surface of the core material, and the wall material is made of urea-formaldehyde resin or epoxy resin.

4. The viscosity-reducing protective film according to claim 3, characterized in that: The thickness of the wall material is 1 μm to 20 μm.

5. The anti-viscosity protective film according to claim 3, characterized in that: The particle size of the core material is 0.5 μm to 15 μm.

6. The anti-viscosity protective film according to claim 3, characterized in that: The core material comprises a thermosensitive dye, a solvent and a developer.

7. The anti-viscosity protective film according to claim 6, characterized in that: The mass ratio of the thermosensitive dye, the solvent and the developer is (0.1-10): (20-80): (1-15).

8. The viscosity-reducing protective film according to claim 6, characterized in that: The thermosensitive dye includes at least one of 1,3-dimethyl-6-diethylaminofluoran, 1,2-benzo-6-diethylaminofluoran, 3,6-dimethoxyfluoran, 2-phenylamino-3-methyl-6-dibutylaminofluoran and 3,3-bis(4-diethylamino-2-ethoxyphenyl)-4-azaphthalide.

9. The viscosity-reducing protective film according to claim 6, characterized in that: The solvent includes at least one of tetradecanol, hexadecanol, ethyl laurate, stearic acid and 2-(4-benzyloxyphenyl)ethyldecanoate.

10. The anti-viscosity protective film according to claim 6, characterized in that: The developer includes at least one of 4-hydroxy-4'-isopropoxydiphenyl sulfone, 4,4'-sulfonylbis[2-(2-propenyl)]phenol, 2,4-di(phenylsulfonyl)phenol and bisphenol A.

11. The viscosity-reducing protective film according to any one of claims 1 to 10, characterized in that: The viscosity-reducing layer comprises acrylate glue and a photoinitiator.

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