Protective film for OLED panel manufacturing process

Abstract

The present invention relates to a protective film for an OLED panel manufacturing process, and more particularly, to a protective film for an OLED panel manufacturing process, which has excellent adhesion retention not only at a low temperature of -10 to -50°C but also at a high temperature of 50 to 100°C, and excellent impact resistance.

Description

Technical Field

[0001] This invention relates to a protective film for OLED panel manufacturing processes, and more specifically, to a protective film for OLED panel manufacturing processes that exhibits excellent adhesion and retention strength and excellent impact resistance not only at low temperatures of -10 to -50°C but also at high temperatures of 50 to 100°C. Background Technology

[0002] Recently, with the rapid development of information and communication technology and the expansion of the market, flat panel displays, as image display devices, have attracted much attention. Typical examples of flat panel displays include liquid crystal displays, plasma display panels, and organic light-emitting diodes (OLEDs).

[0003] Organic light-emitting devices (OLEDs) have advantages such as fast response speed, thinness and small size, low power consumption, self-illumination, and flexibility. Recently, the demand for them in next-generation display devices, flexible display devices, and lighting is increasing.

[0004] Organic light-emitting devices are formed by sequentially depositing transparent electrodes, hole injection layers, hole transport layers, organic light-emitting layers, electron transport layers, electron injection layers, and metal electrodes on a glass substrate. The principle is to use the energy released by the recombination of electrons and holes supplied by the two electrodes on the organic light-emitting layer to emit light.

[0005] Organic light-emitting devices (OLEDs) can degrade due to external factors such as moisture, oxygen, or ultraviolet radiation. Therefore, the packaging technology that seals OLEDs is extremely important. To be suitable for a variety of applications, OLED display devices need to be manufactured in a thin manner.

[0006] On the other hand, in the manufacture of OLED panels, a protective film for protecting the OLED panel is included on the lower and / or upper parts of the OLED panel. For example, if the OLED panel manufacturing method is briefly described, a protective film for the OLED panel manufacturing process is attached to the lower part of the substrate, an encapsulation operation is performed on the upper part of the substrate to create multiple cells spaced apart from each other, a protective film for the OLED panel manufacturing process is covered on the substrate after the cells are made, and then the substrate is cut according to the cells to complete multiple OLED panels.

[0007] At this point, regarding the lower protective film used to protect the OLED panel, the lower protective film of the OLED panel has been used in flexible display devices in the past due to its elasticity and impact resistance. However, its adhesion and retention are not good in different environments, resulting in poor durability due to low adhesion to the OLED panel.

[0008] [Existing Technical Documents]

[0009] [Patent Documents]

[0010] (Patent Document 0001) Korean Patent Publication No. 10-2014-0142240 (Publication Date: 2014.12.11) Summary of the Invention

[0011] [Technical Issues]

[0012] The present invention was developed in view of the problems mentioned above, and aims to provide a protective film for OLED panel manufacturing process that has excellent adhesion and retention strength and excellent impact resistance not only at low temperatures of 10 to -50°C, but also at high temperatures of 50 to 100°C.

[0013] In addition, the objective is to provide a protective film for OLED panel manufacturing processes, which has low moisture permeability (WVTR), excellent adhesion retention not only in high temperature environments of 50~100℃ / high humidity environments of over 80%, but also in thermal shock environments, and excellent elasticity.

[0014] [Technical Solution]

[0015] To address the aforementioned issues, the protective film for OLED panel manufacturing processes of the present invention comprises a base film and an adhesive layer laminated on one side of the base film.

[0016] In a preferred embodiment of the present invention, the adhesive layer may contain a fluorine-substituted polyurethane acrylate copolymer as the main resin.

[0017] In a preferred embodiment of the present invention, the protective film for OLED panel manufacturing process of the present invention can fully satisfy conditions (1) and (2).

[0018] (1) 0.8 ≤ A / B ≤ 5.0

[0019] In the above condition (1), A represents the adhesive force of the adhesive layer measured when the adhesive layer of the protective film is attached to the glass and the protective film base film is peeled off at a speed of 5 mm per second at 25°C. B represents the adhesive retention force of the adhesive layer measured when the adhesive layer of the protective film is attached to the glass and the protective film base film is peeled off at a speed of 5 mm per second at -30°C.

[0020] (2) 0.8 ≤ A / C ≤ 2.5

[0021] In the above condition (2), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 25°C. C represents the adhesive retention force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 60°C.

[0022] In a preferred embodiment of the present invention, the protective film for OLED panel manufacturing process of the present invention does not generate bubbles between the adhesive layer of the protective film and the glass even if the base film of the protective film is impacted after the adhesive layer of the protective film is attached to the glass.

[0023] In a preferred embodiment of the present invention, the weight-average molecular weight of the fluorine-substituted polyurethane acrylate copolymer can be 5,000 to 1,000,000.

[0024] In a preferred embodiment of the present invention, the fluorinated polyurethane acrylate copolymer may contain repeating units derived from hydroxyl-terminated perfluoropolyether.

[0025] In a preferred embodiment of the present invention, the hydroxyl-terminated perfluoropolyether may contain 2 to 10 fluorine molecules.

[0026] In a preferred embodiment of the present invention, the adhesive layer may further comprise an acrylate monomer.

[0027] In a preferred embodiment of the present invention, the acrylate monomer may include a compound represented by the following chemical formula 1, a compound represented by the following chemical formula 2, a compound represented by the following chemical formula 3, and isobornyl acrylate.

[0028] [Chemical Formula 1]

[0029]

[0030] In the above chemical formula 1, B1 is -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2- or -CH2CH2CH2CH2CH2-, and R1 and R2 are independently C1~C12 straight-chain alkyl, C3~C12 branched alkyl, phenyl or alkylphenyl.

[0031] [Chemical Formula 2]

[0032]

[0033] In the above chemical formula 2, B3 is -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, or -CH2CH2CH2CH2CH2CH2-.

[0034] [Chemical Formula 3]

[0035]

[0036] In the above chemical formula 3, B2 is -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2CH2CH2-, or -CH2CH2CH2CH2CH2CH2CH2CH2-.

[0037] In a preferred embodiment of the present invention, the adhesive layer may contain 1 to 10 parts by weight of the compound represented by the above chemical formula 1, 1 to 10 parts by weight of the compound represented by the above chemical formula 2, 1 to 10 parts by weight of the compound represented by the above chemical formula 3, and 15 to 35 parts by weight of isobornyl acrylate, relative to 100 parts by weight of the main resin.

[0038] In a preferred embodiment of the present invention, the base film may be a permanent antistatic film comprising a permanent antistatic agent and a plastic resin.

[0039] In a preferred embodiment of the present invention, the base film and adhesive layer of the protective film for OLED panel manufacturing process of the present invention can have a thickness ratio of 1:0.13~0.66.

[0040] In a preferred embodiment of the present invention, the adhesive layer may further comprise a photoinitiator and an antistatic agent.

[0041] In a preferred embodiment of the present invention, the protective film for OLED panel manufacturing process of the present invention may also satisfy conditions (6) and (7).

[0042] (6) 0.8 ≤ A / W ≤ 1.5

[0043] In the above condition (6), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second at 25°C after the adhesive layer of the protective film is attached to the glass, and W represents the adhesive retention force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second at 0°C after the adhesive layer of the protective film is attached to the glass.

[0044] (7) 0.8 ≤ A / Y ≤ 1.5

[0045] In the above conditions (7), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at 180° at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 25°C. Y represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at 180° at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 0°C for 1000 hours, aged at 25°C for 4 hours, and then peeling the base film of the protective film at 25°C for 180° at a speed of 5 mm per second.

[0046] In a preferred embodiment of the present invention, the protective film for OLED panel manufacturing process of the present invention may also satisfy conditions (8) and (9).

[0047] (8) 0.4 ≤ A / H ≤ 1.5

[0048] In the above conditions (8), A represents the adhesive force of the adhesive layer after the adhesive layer of the protective film is attached to the glass and the base film of the protective film is peeled off at a speed of 5 mm per second at 25°C and measured. H represents the adhesive force of the adhesive layer after the adhesive layer of the protective film is attached to the glass, exposed at a temperature of -30°C for 500 hours, aged at a temperature of 25°C for 4 hours, and the base film of the protective film is peeled off at a speed of 5 mm per second at 25°C and measured.

[0049] (9) 0.4 ≤ A / Z ≤ 1.0

[0050] In the above conditions (9), A represents the adhesive force of the adhesive layer measured by peeling the protective film base film at 180° at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 25°C. Z represents the adhesive force of the adhesive layer measured by peeling the protective film base film at 180° at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 60°C for 1000 hours, aged at 25°C for 4 hours, and then peeling the protective film base film at 25°C for 180° at a speed of 5 mm per second.

[0051] [Invention Effects]

[0052] The protective film of the present invention for OLED panel manufacturing process maintains excellent adhesion and impact resistance not only at low temperatures of 10 to -50°C, but also at high temperatures of 50 to 100°C.

[0053] In addition, the protective film for OLED panel manufacturing process of the present invention has low moisture permeability (WVTR), and has excellent adhesion retention not only in high temperature environment of 50~100°C / high humidity environment of more than 80%, but also in thermal shock environment, while having excellent elasticity. Attached Figure Description

[0054] Figure 1 As a preferred embodiment of the present invention, a simplified cross-sectional view of the protective film for OLED panel manufacturing process is shown. Detailed Implementation

[0055] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can readily implement the invention. The present invention can be implemented in many different forms and is not limited to the embodiments described herein. In the drawings, for the purpose of clearly describing the invention, parts unrelated to the description have been omitted, and the same or similar constituent elements throughout the specification have been given the same reference numerals.

[0056] Reference Figure 1 The protective film for OLED panel manufacturing process of the present invention includes a base film (10) and an adhesive layer (20) laminated on one side of the base film (10).

[0057] In addition, a release film (30) can be stacked on one side of the adhesive layer (20). The protective film for OLED panel manufacturing process of the present invention can be formed by stacking a base film (10), an adhesive layer (20) and a release film (30) in sequence.

[0058] The base film (10) is directly attached to the surface of the OLED panel, serving to protect the surface of the OLED panel. The base film (10) can include materials commonly used in the industry for protective films without limitation; preferably, it can be a permanent antistatic film comprising a permanent antistatic agent and a plastic resin. In other words, the base film of the present invention is not a film coated with an antistatic agent that can be removed by physical force, but rather a film with permanent antistatic effect formed by mixing a permanent antistatic agent within the film during film processing. In this case, the permanent antistatic agent can include any antistatic agent used in the industry; preferably, it can include one or more selected from PEO, Nylon-co-PEO, Butadiene-co-PEO, PET-co-PEO, styrene-co-PEO, and IDP (Inherently Dissipative Polymer). Additionally, the plastic resin can include, but is not limited to, one or more selected from PP resin, PET resin, and PE resin.

[0059] In addition, the thickness of the base film (10) is not limited as long as it is a base film thickness that can usually be used for protective films. Preferably, it can be 50 to 100 mm, more preferably 70 to 80 mm, but not limited thereto.

[0060] The adhesive layer (20) exerts a predetermined adhesive force to allow the base film (10) to adhere to the upper and / or lower parts of the OLED panel, preferably to the lower part. The adhesive layer (20) of the present invention may contain a fluorine-substituted urethane acrylate copolymer as the main resin. Here, the main resin refers to the basic substance used to enable the adhesive layer (20) to have adhesive force; in other words, it refers to the component that accounts for more than 50% by weight of the acrylate constituting the adhesive layer.

[0061] The weight-average molecular weight of the fluorinated polyurethane acrylate copolymer of the present invention can be 5,000 to 1,000,000, preferably 10,000 to 500,000, more preferably 10,000 to 200,000. If the weight-average molecular weight is less than 5,000, there will be a problem of low adhesion. If it exceeds 1,000,000, the reactivity will decrease, and there will be a problem of unreacted oligomers being generated.

[0062] Furthermore, the fluorinated polyurethane acrylate copolymers of the present invention may include repeating units derived from hydroxyl-terminated perfluoropolyethers. In other words, hydroxyl-terminated perfluoropolyethers can be used in the synthesis of the fluorinated polyurethane acrylate copolymers of the present invention, and these hydroxyl-terminated perfluoropolyethers can be incorporated into the backbone of the fluorinated polyurethane acrylate copolymers of the present invention.

[0063] On the other hand, hydroxyl-terminated perfluoropolyethers may include 2 to 10 fluorine molecules, preferably 3 to 8 fluorine molecules, more preferably 3 to 6 fluorine molecules. If there are fewer than 2 fluorine molecules, there will be problems with increased moisture permeability or low adhesion retention under different environments. If there are more than 10 substituted fluorine molecules, there will be problems with low adhesion retention under different environments.

[0064] On the other hand, the adhesive layer (20) may contain acrylate monomers in addition to the main resin.

[0065] At this time, the acrylate monomer may include one or more compounds selected from the following chemical formula 1, the following chemical formula 2, the following chemical formula 3 and isobornyl acrylate. Preferably, it may include the following chemical formula 1, the following chemical formula 2, the following chemical formula 3 and isobornyl acrylate.

[0066] [Chemical Formula 1]

[0067]

[0068] In the above chemical formula 1, B1 is -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2- or -CH2CH2CH2CH2CH2-, preferably -CH2-, -CH2CH2- or -CH2CH2CH2-.

[0069] In addition, in the chemical formula 1, R1 and R2 are independently C1-C12 straight-chain alkyl, C3-C12 branched alkyl, phenyl or alkylphenyl, preferably C1-C12 straight-chain alkyl, more preferably R1 is ethyl and R2 is butyl.

[0070] [Chemical Formula 2]

[0071]

[0072] In the above chemical formula 2, B3 is -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2- or -CH2CH2CH2CH2CH2CH2-, preferably -CH2-, -CH2CH2- or -CH2CH2CH2-.

[0073] [Chemical Formula 3]

[0074]

[0075] In the above chemical formula 3, B2 is -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2CH2CH2- or -CH2CH2CH2CH2CH2CH2CH2CH2-, preferably -CH2CH2CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2CH2CH2- or -CH2CH2CH2CH2CH2CH2CH2-.

[0076] Specifically, the adhesive layer (20) may contain 1 to 10 parts by weight of the compound represented by the above chemical formula 1 relative to 100 parts by weight of the main resin, preferably 3 to 7 parts by weight. If it exceeds the weight range described above, there will be a problem that the physical properties desired by the present invention cannot be met.

[0077] In addition, the adhesive layer (20) may contain 1 to 10 parts by weight of the compound represented by the above chemical formula 2 relative to 100 parts by weight of the main resin, preferably 3 to 7 parts by weight. If it exceeds the weight range described above, there will be a problem that the physical properties desired by the present invention cannot be met.

[0078] In addition, the adhesive layer (20) may contain 1 to 10 parts by weight of the compound represented by the above chemical formula 3 relative to 100 parts by weight of the main resin, preferably 3 to 7 parts by weight. If it exceeds the weight range described above, there will be a problem that the physical properties desired by the present invention cannot be met.

[0079] In addition, the adhesive layer (20) may contain 15 to 35 parts by weight of isobornyl acrylate relative to 100 parts by weight of the main resin, preferably 20 to 30 parts by weight. If it exceeds the weight range described above, there will be a problem that the physical properties desired by the present invention cannot be met.

[0080] Furthermore, the adhesive layer (20) of the present invention may also contain one or more selected from photoinitiators and antistatic agents, preferably, it may also contain photoinitiators and antistatic agents.

[0081] A photoinitiator is a substance that absorbs energy from an ultraviolet light source and promotes a curing reaction. It can be included without limitation as long as it is a photoinitiator commonly used in the industry for protective films. Preferably, it can include compounds represented by the following chemical formula 4.

[0082] [Chemical Formula 4]

[0083]

[0084] In the above chemical formula 4, R3, R4, R5, R7 and R8 are independently -H, a straight-chain alkyl group of C1 to C12, a branched alkyl group of C3 to C12, a phenyl or an alkylphenyl group, preferably -H or a straight-chain alkyl group of C1 to C12.

[0085] Antistatic agents are substances that prevent static electricity. Any antistatic agent that is commonly used in the industry to protect films can be included without limitation.

[0086] In addition, the adhesive layer (20) may contain 0.1 to 5 parts by weight of photoinitiator relative to 100 parts by weight of the main resin, preferably 0.5 to 1.5 parts by weight.

[0087] In addition, the adhesive layer (20) may contain 0.01 to 1 part by weight of antistatic agent relative to 100 parts by weight of the main resin, preferably 0.1 to 0.4 parts by weight.

[0088] In addition, the thickness of the adhesive layer (20) is not limited by the thickness of the base film. Preferably, it can be 5 to 30 mm, more preferably 10 to 20 mm, but it is not limited thereto.

[0089] On the other hand, the base film (10) and adhesive layer (20) of the protective film for OLED panel manufacturing process of the present invention can have a thickness ratio of 1:0.13 to 0.66, preferably, a thickness ratio of 1:0.15 to 0.4, and more preferably, a thickness ratio of 1:0.15 to 0.3.

[0090] Furthermore, the moisture permeability (WVTR) of the adhesive layer (20) of the present invention, measured according to ASTM E-398 test specifications, can be 15 g / m³. 2 For days or less, preferably, the concentration can be 1~10 g / m³. 2 • For better results, the concentration can be 2~8g / m³. 2 ·days, and even more preferably, can be 3~5g / m 2 ·sky.

[0091] The release film (30) can be included without limitation as long as it is a material commonly used in the industry for release films. Preferably, it can include a PET (polyethylene terephthalate) film, and more preferably, it can include a PET film that has undergone silicone release treatment. Furthermore, the thickness of the release film (30) is not limited as long as it is a thickness commonly used for protective films. Preferably, it can be 10 to 50 mm, more preferably 20 to 30 mm, but it is not limited thereto.

[0092] Furthermore, the protective film for OLED panel manufacturing process of the present invention can meet the following condition (1).

[0093] (1) 0.8 ≤ A / B ≤ 5.0, preferably, 0.9 ≤ A / B ≤ 2.0, more preferably, 1.2 ≤ A / B ≤ 1.6, and even more preferably, 1.3 ≤ A / B ≤ 1.5

[0094] In the above condition (1), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 25°C.

[0095] In the above condition (1), B represents the adhesive holding force of the adhesive layer after the adhesive layer of the protective film is attached to the glass and the protective film base film is peeled off at a speed of 5 mm per second at a temperature of -30°C.

[0096] In addition, the protective film for OLED panel manufacturing process of the present invention may also satisfy the following condition (2).

[0097] (2) 0.8 ≤ A / C ≤ 2.5, preferably, 0.9 ≤ A / C ≤ 2.0, more preferably, 1.0 ≤ A / C ≤ 1.5, and even more preferably, 1.1 ≤ A / C ≤ 1.3

[0098] In the above condition (2), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 25°C.

[0099] In the above condition (2), C represents the adhesive holding force of the adhesive layer after the adhesive layer of the protective film is attached to the glass and the protective film base film is peeled off at a speed of 5 mm per second at 60°C.

[0100] In addition, the protective film for OLED panel manufacturing process of the present invention may also satisfy the following condition (3).

[0101] (3) 0.3≤A / D≤1.5, preferably, 0.5≤A / D≤1.2, more preferably, 0.7≤A / D≤1.0, and even more preferably, 0.8≤A / D≤0.9

[0102] In the above condition (3), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 25°C.

[0103] In the above condition (3), D represents the adhesive strength of the adhesive layer after the protective film is attached to the glass and repeatedly exposed to -20°C for 30 minutes and 60°C for 30 minutes 100 times, aged at 25°C for 4 hours, and then peeled off the protective film base film at 25°C at a speed of 5 mm per second at 180°.

[0104] In addition, the protective film for OLED panel manufacturing process of the present invention may also satisfy the following condition (4).

[0105] (4) 0.5 ≤ A / E ≤ 1.0, preferably, 0.5 ≤ A / E ≤ 0.9, more preferably, 0.5 ≤ A / E ≤ 0.8, and even more preferably, 0.55 ≤ A / E ≤ 0.7

[0106] In the above condition (4), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 25°C.

[0107] In the above conditions (4), E represents the adhesive strength of the adhesive layer when the adhesive layer of the protective film is attached to the glass, exposed at 60°C and 90% humidity for 500 hours, aged at 25°C for 4 hours, and then peeled off at 25°C at a speed of 5 mm per second at 180°.

[0108] In addition, the protective film for OLED panel manufacturing process of the present invention may also meet the following condition (5).

[0109] (5) 1.0 ≤ A / F ≤ 2.0, preferably, 1.0 ≤ A / F ≤ 1.6, more preferably, 1.1 ≤ A / F ≤ 1.4, and even more preferably, 1.2 ≤ A / F ≤ 1.3

[0110] In the above condition (5), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 25°C.

[0111] In the above conditions (5), F represents the adhesive strength of the adhesive layer when the adhesive layer of the protective film is attached to the glass, exposed at 85°C and 85% humidity for 500 hours, aged at 25°C for 4 hours, and then peeled off at 25°C at a speed of 5 mm per second at 180°.

[0112] In addition, the protective film for OLED panel manufacturing process of the present invention may also satisfy the following condition (6).

[0113] (6) 0.8 ≤ A / W ≤ 1.5, preferably, 1.0 ≤ A / W ≤ 1.4, more preferably, 1.1 ≤ A / W ≤ 1.3, and even more preferably, 1.15 ≤ A / W ≤ 1.25

[0114] In the above condition (6), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 25°C.

[0115] In the above condition (6), W represents the adhesive holding force of the adhesive layer after the adhesive layer of the protective film is attached to the glass and the protective film base film is peeled off at a speed of 5 mm per second at 0°C.

[0116] In addition, the protective film for OLED panel manufacturing process of the present invention may also satisfy the following condition (7).

[0117] (7) 0.8 ≤ A / Y ≤ 1.5, preferably, 0.8 ≤ A / Y ≤ 1.3, more preferably, 0.9 ≤ A / Y ≤ 1.2, and even more preferably, 1.0 ≤ A / Y ≤ 1.1

[0118] In the above condition (7), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 25°C.

[0119] In the above conditions (7), Y represents the adhesive strength of the adhesive layer when the adhesive layer of the protective film is attached to the glass, exposed at 0°C for 1000 hours, aged at 25°C for 4 hours, and then peeled off at 25°C at a speed of 5 mm per second at 180°.

[0120] In addition, the protective film for OLED panel manufacturing process of the present invention may also satisfy the following condition (8).

[0121] (8) 0.4 ≤ A / H ≤ 1.5, preferably, 0.8 ≤ A / H ≤ 1.4, more preferably, 1.0 ≤ A / H ≤ 1.3, and even more preferably, 1.05 ≤ A / H ≤ 1.25

[0122] In the above condition (8), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 25°C.

[0123] In the above conditions (8), H represents the adhesive strength of the adhesive layer when the adhesive layer of the protective film is attached to the glass, exposed at -30°C for 500 hours, aged at 25°C for 4 hours, and then peeled off at 25°C at a speed of 5 mm per second at 180°.

[0124] In addition, the protective film for OLED panel manufacturing process of the present invention may also satisfy the following condition (9).

[0125] (9) 0.4 ≤ A / Z ≤ 1.0, preferably, 0.4 ≤ A / Z ≤ 0.9, more preferably, 0.4 ≤ A / Z ≤ 0.8, and even more preferably, 0.5 ≤ A / Z ≤ 0.7

[0126] In the above condition (9), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass at 25°C.

[0127] In the above conditions (9), Z represents the adhesive strength of the adhesive layer when the adhesive layer of the protective film is attached to the glass, exposed at 60°C for 1000 hours, aged at 25°C for 4 hours, and then peeled off at 25°C at a speed of 5 mm per second at 180°.

[0128] On the other hand, the protective film for OLED panel manufacturing process of the present invention, after the adhesive layer of the protective film is attached to the glass, will not generate bubbles between the adhesive layer of the protective film and the glass even if the base film of the protective film is impacted.

[0129] Furthermore, the protective film for OLED panel manufacturing processes of the present invention does not develop cracks after the adhesive layer of the protective film is attached to the polyimide film and is evaluated with a curvature radius of 3.0 mm through 10,000 bending cycles.

[0130] Furthermore, the method for preparing the protective film for OLED panel manufacturing process of the present invention may include a first step to a third step.

[0131] Firstly, the first step of the method for preparing a protective film for OLED panel manufacturing process of the present invention can prepare an adhesive composition.

[0132] The adhesive composition can be prepared by mixing acrylate monomers into the main resin. Preferably, it can be prepared by mixing acrylate monomers, a photoinitiator, an antistatic agent, and a solvent into the main resin. In this case, any solvent commonly used in the industry can be used without restriction; preferably, toluene can be used.

[0133] More specifically, the adhesive composition may be prepared by mixing 1 to 10 parts by weight of the compound represented by the above chemical formula 1 with 100 parts by weight of the main resin, preferably 3 to 7 parts by weight.

[0134] In addition, the adhesive composition can be prepared by mixing 1 to 10 parts by weight of the compound represented by the above chemical formula 2 with 100 parts by weight of the main resin, preferably 3 to 7 parts by weight.

[0135] In addition, the adhesive composition can be prepared by mixing 1 to 10 parts by weight of the compound represented by the above chemical formula 3 with 100 parts by weight of the main resin, preferably by mixing 3 to 7 parts by weight.

[0136] In addition, the adhesive composition can be prepared by mixing 15 to 35 parts by weight of isobornyl acrylate with 100 parts by weight of the main resin, preferably 20 to 30 parts by weight.

[0137] In addition, the adhesive composition can be prepared by mixing 0.1 to 5 parts by weight of photoinitiator with 100 parts by weight of the main resin, preferably 0.5 to 1.5 parts by weight.

[0138] In addition, the adhesive composition can be prepared by mixing 0.01 to 1 part by weight of antistatic agent with 100 parts by weight of the main resin, preferably 0.1 to 0.4 parts by weight.

[0139] In addition, the adhesive composition can be prepared by mixing 10 to 50 parts by weight of solvent with 100 parts by weight of the main resin, preferably 20 to 40 parts by weight.

[0140] Then, in the second step of the method for preparing the protective film for OLED panel manufacturing process of the present invention, the adhesive composition prepared in the first step can be coated on one side of the base film and dried. At this time, the drying can be performed at a temperature of 100~150°C, preferably at a temperature of 115~135°C.

[0141] Finally, the third step of the method for preparing the protective film for OLED panel manufacturing process of the present invention can be to apply and dry the adhesive composition in the second step to one side of the release film and then cure it to prepare a protective film for OLED panel manufacturing process, which is formed by sequentially stacking a base film, an adhesive layer formed by curing the adhesive composition, and a release film.

[0142] At this point, the bonding can be performed using a laminator, and the curing after bonding can be performed by irradiating 500~1500mJ of UV light, preferably 800~1200mJ of UV light.

[0143] The present invention has been described above primarily in terms of its implementation forms, but these are merely examples and do not limit the scope of the invention. Those skilled in the art will understand that various modifications and applications not listed above can be implemented without departing from the essential characteristics of the invention. For example, the constituent elements specifically shown in the implementation forms of the present invention can be modified. Furthermore, it should be interpreted that differences related to such modifications and applications are included within the scope of the invention as defined in the claims.

[0144] Example 1: Preparation of a protective film for OLED panel manufacturing process

[0145] (1) A fluorinated polyurethane acrylate copolymer (weight average molecular weight: 16000, containing repeating units derived from perfluoropolyethers with 4 fluorinated hydroxyl-terminated ends, BNO-4.0F) was prepared as the main resin. Relative to 100 parts by weight of the main resin, 5 parts by weight of the compound represented by the following chemical formula 1-1, 5 parts by weight of the compound represented by the following chemical formula 2-1, 5 parts by weight of the compound represented by the following chemical formula 3-1, 25 parts by weight of isobornyl acrylate, 1 part by weight of the compound represented by the following chemical formula 4-1 as a photoinitiator, 0.2 parts by weight of the antistatic agent (BYK-ES-80, BYK Chemical Company) and 30 parts by weight of toluene as a solvent were mixed to prepare an adhesive composition.

[0146] [Chemical Formula 1-1]

[0147]

[0148] In the above chemical formula 1-1, B1 is -CH2-, R1 is ethyl, and R2 is butyl.

[0149] [Chemical Formula 2-1]

[0150]

[0151] In the above chemical formula 2-1, B3 is -CH2CH2-.

[0152] [Chemical Formula 3-1]

[0153]

[0154] In the above chemical formula 3-1, B2 is -CH2CH2CH2CH2CH2CH2-.

[0155] [Chemical Formula 4-1]

[0156]

[0157] In the above chemical formula 4-1, R3, R5 and R7 are methyl groups, and R4 and R6 are -H groups.

[0158] (2) Prepare a 75 mm thick permanent antistatic film (a film made by mixing a permanent antistatic agent in PET resin) as a base film. Use a slit coater to coat one side of the base film with the prepared adhesive composition and then perform hot air drying at 125°C.

[0159] (3) On one side of the adhesive composition that has been coated and hot-air dried, a 25 mm thick release film (using a PET film with one side treated with silicone release) is laminated (= the release film side is laminated with the adhesive composition side to side) using a laminating roller, and then irradiated with 1000 mJ of UV light to prepare a protective film for the OLED panel manufacturing process, which consists of a base film, a 15 mm thick adhesive layer formed by curing the adhesive composition, and a release film stacked in sequence.

[0160] Example 2: Preparation of a protective film for OLED panel manufacturing process

[0161] A protective film for OLED panel manufacturing was prepared using the same method as in Example 1. However, unlike Example 1, a fluorinated polyurethane acrylate copolymer containing repeating units of 8 fluorinated hydroxyl-terminated perfluoropolyethers was used as the main resin to ultimately prepare the protective film for OLED panel manufacturing.

[0162] Example 3: Preparation of a protective film for OLED panel manufacturing process

[0163] A protective film for OLED panel manufacturing was prepared using the same method as in Example 1. However, unlike Example 1, a fluorinated polyurethane acrylate copolymer containing repeating units of fluorinated hydroxyl-terminated perfluoropolyethers with two fluorine ions was used as the main resin to ultimately prepare the protective film for OLED panel manufacturing.

[0164] Example 4: Preparation of a protective film for OLED panel manufacturing process

[0165] A protective film for OLED panel manufacturing was prepared using the same method as in Example 1. However, unlike Example 1, an adhesive composition was prepared by mixing 4.167 parts by weight of the compound represented by the above chemical formula 1-1, 4.167 parts by weight of the compound represented by the above chemical formula 2-1, 4.167 parts by weight of the compound represented by the above chemical formula 3-1, 20.833 parts by weight of isobornyl acrylate, 0.833 parts by weight of the compound represented by the following chemical formula 4-1 as a photoinitiator, 0.167 parts by weight of the antistatic agent (BYK-ES-80, BYK Chemical Company), and 25 parts by weight of toluene as a solvent, with respect to 100 parts by weight of the main resin. This resulted in the final preparation of a protective film for OLED panel manufacturing.

[0166] Example 5: Preparation of a protective film for OLED panel manufacturing process

[0167] A protective film for OLED panel manufacturing was prepared using the same method as in Example 1. However, unlike Example 1, tricyclodecanedimethanol diacrylate was used instead of the compound represented by the above chemical formula 3-1, and a protective film for OLED panel manufacturing was finally prepared.

[0168] Example 6: Preparation of a protective film for OLED panel manufacturing process

[0169] A protective film for OLED panel manufacturing was prepared using the same method as in Example 1. However, unlike Example 1, the adhesive composition was prepared without mixing an antistatic agent, ultimately resulting in a protective film for OLED panel manufacturing.

[0170] Example 7: Preparation of a protective film for OLED panel manufacturing process

[0171] A protective film for OLED panel manufacturing was prepared using the same method as in Example 1. However, unlike Example 1, instead of a permanent antistatic film with a thickness of 75 mm, a PET film with an antistatic layer formed by coating both sides with PEDOT / PSS (poly(3,4-ethylenedioxythiophene)-poly(styrene sulfonic acid)) was used to prepare the protective film for OLED panel manufacturing.

[0172] Comparative Example 1: Preparation of a protective film for OLED panel manufacturing process

[0173] A protective film for OLED panel manufacturing was prepared using the same method as in Example 1. However, unlike Example 1, a non-fluorinated polyurethane acrylate copolymer was used as the main resin, and the resulting protective film for OLED panel manufacturing was prepared.

[0174] Comparative Example 2: Preparation of a protective film for OLED panel manufacturing process

[0175] A protective film for OLED panel manufacturing was prepared using the same method as in Example 1. However, unlike Example 1, polybutyl methacrylate was used as the main resin to ultimately prepare the protective film for OLED panel manufacturing.

[0176] Comparative Example 3: Preparation of Protective Film for OLED Panel Manufacturing Process

[0177] A protective film for OLED panel manufacturing was prepared using the same method as in Example 1. However, unlike Example 1, epoxy acrylate was used as the main resin to ultimately prepare the protective film for OLED panel manufacturing.

[0178] Comparative Example 4: Preparation of Protective Films for OLED Panel Manufacturing Processes

[0179] A protective film for OLED panel manufacturing was prepared using the same method as in Example 1. However, unlike Example 1, when preparing the adhesive composition, 10 parts by weight of the compound represented by the above chemical formula 1-1, 5 parts by weight of the compound represented by the above chemical formula 3-1, 25 parts by weight of isobornyl acrylate, 1 part by weight of the compound represented by the above chemical formula 4-1 as a photoinitiator, 0.2 parts by weight of the antistatic agent (BYK-ES-80, BYK Chemical Company), and 30 parts by weight of toluene as a solvent were mixed relative to 100 parts by weight of the main resin to prepare the adhesive composition, and finally a protective film for OLED panel manufacturing was prepared.

[0180] Comparative Example 5: Preparation of a protective film for OLED panel manufacturing process

[0181] A protective film for OLED panel manufacturing was prepared using the same method as in Example 1. However, unlike in Example 1, tricyclodecanedimethanol diacrylate was used instead of isobornyl acrylate to ultimately prepare the protective film for OLED panel manufacturing.

[0182] Experimental Example 1

[0183] The protective films prepared in Examples 1-7 and Comparative Examples 1-5 for use in the OLED panel manufacturing process were evaluated according to the following physical property evaluation method, and the results are shown in Tables 1-2.

[0184] (1) Adhesive layer adhesion (marked as A in the table below).

[0185] After removing the release film of the protective film, the adhesive layer of the protective film was attached to the non-alkali glass at 25°C using a laminator. After aging at 25°C for 24 hours, the base film of the protective film was peeled off at 180° at 25°C using a UTM at a speed of 5 mm per second. The adhesion of the adhesive layer was then measured.

[0186] (2) Adhesive layer adhesion retention force (marked as B in the table below).

[0187] After removing the release film of the protective film, the adhesive layer of the protective film was attached to the non-alkali glass at 25°C using a laminator. After aging at 25°C for 24 hours, the base film of the protective film was peeled off at 180° at -30°C using a UTM at a speed of 5 mm per second. The adhesive holding force of the adhesive layer was then measured.

[0188] (3) Adhesive holding power of the adhesive layer (marked as W in the table below).

[0189] After removing the release film of the protective film, the adhesive layer of the protective film was attached to the non-alkali glass at 25°C using a laminator. After aging at 25°C for 24 hours, the base film of the protective film was peeled off at 0°C at a speed of 5 mm per second using a UTM, and the adhesive holding force of the adhesive layer was measured.

[0190] (4) Adhesive holding power of the adhesive layer (marked as C in the table below).

[0191] After removing the release film of the protective film, the adhesive layer of the protective film was attached to the non-alkali glass at 25°C using a laminator. After aging at 25°C for 24 hours, the base film of the protective film was peeled off at 60°C at a speed of 5 mm per second using a UTM, and the adhesive holding force of the adhesive layer was measured.

[0192] (5) Adhesive layer adhesion (marked as H in the table below).

[0193] After removing the release film of the protective film, the adhesive layer of the protective film was attached to non-alkali glass at 25°C using a laminator. After being exposed at -30°C for 500 hours and aged at 25°C for 4 hours, the base film of the protective film was peeled off at 180° at 25°C at a speed of 5 mm per second using a UTM. The adhesion of the adhesive layer was then measured.

[0194] (6) Adhesive layer adhesion (marked as Y in the table below).

[0195] After removing the release film of the protective film, the adhesive layer of the protective film was attached to non-alkali glass at 25°C using a laminator. After being exposed at 0°C for 1000 hours and aged at 25°C for 4 hours, the base film of the protective film was peeled off at 180° at 25°C at a speed of 5 mm per second using a UTM. The adhesion of the adhesive layer was then measured.

[0196] (7) Adhesive layer adhesion (marked as Z in the table below).

[0197] After removing the release film of the protective film, the adhesive layer of the protective film was attached to non-alkali glass at 25°C using a laminator. After being exposed at 60°C for 1000 hours and aged at 25°C for 4 hours, the base film of the protective film was peeled off at 180° at 25°C at a speed of 5 mm per second using a UTM. The adhesion of the adhesive layer was then measured.

[0198] (8) Adhesive layer adhesion (marked as D in the table below).

[0199] After removing the release film of the protective film, the adhesive layer of the protective film was attached to non-alkali glass at 25°C using a laminator. After repeated exposures of 30 minutes at -20°C and 30 minutes at 60°C for 100 times, and then aged at 25°C for 4 hours, the base film of the protective film was peeled off at 180° at 25°C at a speed of 5 mm per second using a UTM, and the adhesion of the adhesive layer was measured.

[0200] (9) Adhesive layer adhesion (marked as E in the table below).

[0201] After removing the release film of the protective film, the adhesive layer of the protective film was attached to non-alkali glass at 25°C using a laminator. After being exposed at 60°C and 90% humidity for 500 hours, and then aged at 25°C for 4 hours, the base film of the protective film was peeled off at 180° at 25°C and 5 mm per second using a UTM. The adhesion of the adhesive layer was then measured.

[0202] (10) Adhesive layer adhesion (marked as F in the table below).

[0203] After removing the release film of the protective film, the adhesive layer of the protective film was attached to non-alkali glass at 25°C using a laminator. After being exposed at 85°C and 85% humidity for 500 hours, and then aged at 25°C for 4 hours, the base film of the protective film was peeled off at 180° at 25°C and 5 mm per second using a UTM. The adhesion of the adhesive layer was then measured.

[0204] (11) Water vapor transmission rate (WVTR)

[0205] The adhesive compositions prepared in Examples 1-7 and Comparative Examples 1-5 were coated onto one side of a silicone-release-treated PET film and dried in a drying oven at 125°C for 6 minutes. The silicone-release-treated PET film was then laminated with a laminating roller (with the release-treated side facing the adhesive composition) on the coated and dried side of the adhesive composition. The adhesive composition was then cured by irradiation with 1000 mJ of UV light to form an adhesive layer with a thickness of 100 mm. The moisture permeability of the formed adhesive layer was measured using a Permatran instrument from Memcon according to ASTM E-398 test specifications.

[0206] (12) Stripping electrostatic voltage

[0207] The protective film was cut into 100mm × 100mm (length × width) pieces, and the release film was peeled off at a speed of 80mm per second at 180°. The peel electrostatic voltage (V) of the adhesive layer was measured. The measurement was repeated 5 times. If the average value was below 0.05kV, it was rated as ○; if it exceeded 0.05kV, it was rated as ×.

[0208] (13) Impact resistance

[0209] After removing the release film of the protective film, the adhesive layer of the protective film is attached to the non-alkali glass at 25°C using a laminator. After 24 hours, a 100g ball hammer is dropped vertically from a height of 10cm onto the base film of the protective film. If no air bubbles occur between the adhesive layer and the non-alkali glass, the impact resistance is rated as ○; if air bubbles occur, the rating is ×.

[0210] (14) Evaluation of bending performance

[0211] After removing the release film from the protective film, the adhesive layer of the protective film is attached to the polyimide film at 25°C using a laminating machine. The film is then cut into 25mm × 150mm (length × width) pieces. The cut polyimide films with the attached protective film are then placed end-to-end and subjected to 10,000 bending cycles with a radius of curvature of 3.0mm. If no cracks occur, the bending performance is rated ○; if cracks occur, it is rated ×.

[0212] Table 1

[0213] category Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 A (gf / 25mm) 1625 1532 1580 1335 1243 1600 B (gf / 25mm) 1125 1132 1098 1285 714 1157 W (gf / 25mm) 1344 1520 1250 1334 888 1320 C (gf / 25mm) 1286 1090 1132 883 1225 1322 H (gf / 25mm) 1414 1486 1217 1148 895 1408 Y (gf / 25mm) 1544 1425 1438 1402 957 1497 Z (gf / 25mm) 2633 2298 1975 1829 2113 2671 D (gf / 25mm) 1918 1777 1517 1135 1492 1813 E (gf / 25mm) 2649 2604 1754 2096 2026 2120 F (gf / 25mm) 1305 1302 1153 1135 1032 1140 Condition (1) 1.44 1.35 1.44 1.04 1.74 1.38 Condition (2) 1.26 1.41 1.40 1.51 1.01 1.21 Condition (3) 0.85 0.86 1.04 1.18 0.83 0.88 Condition (4) 0.61 0.59 0.90 0.64 0.61 0.75 Condition (5) 1.25 1.18 1.37 1.18 1.20 1.40 Condition (6) 1.21 1.01 1.26 1.00 1.40 1.21 Condition (7) 1.05 1.08 1.10 0.95 1.30 1.07 Condition (8) 1.15 1.03 1.30 1.16 1.39 1.14 Condition (9) 0.62 0.67 0.80 0.73 0.59 0.60 <![CDATA[Water vapor transmission rate (g / m 2 .day)]]> 3.9 2.5 11.5 3.8 8.8 3.9 Stripping electrostatic voltage O O O O O O Impact resistance O O O O O O Bending performance evaluation O O O O O O

[0214] Table 2

[0215]

[0216] As shown in Tables 1 and 2, it can be confirmed that the protective film prepared in Example 1 for OLED panel manufacturing process has excellent adhesion and retention at low temperatures of -10 to -50°C and high temperatures of 50 to 100°C, as well as excellent impact resistance. It has low moisture permeability (WVTR) and excellent adhesion and retention not only at high temperatures of 50 to 100°C and high humidity of over 80%, but also under thermal shock conditions. It also has excellent elasticity.

[0217] Those skilled in the art can readily implement simple variations or modifications of the present invention, and such variations or modifications are all considered to be included within the present invention.

[0218] [Attached image labels]

[0219] 10: Base membrane

[0220] 20: Adhesive layer

[0221] 30: Release film

Claims

1. A protective film for OLED panel manufacturing process, comprising a base film and an adhesive layer laminated on one side of the base film, characterized in that, The adhesive layer comprises a fluorine-substituted polyurethane acrylate copolymer as the main resin. The protective film satisfies conditions (1) and (2). After the adhesive layer of the protective film is attached to the glass, even if the base film of the protective film is impacted, no air bubbles will be generated between the adhesive layer of the protective film and the glass. (1) 0.8 ≤ A / B ≤ 5.0 (2) 0.8 ≤ A / C ≤ 2.5 In conditions (1) and (2), A represents the adhesive force of the adhesive layer measured by peeling the base film of the protective film at 180°C at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass and aged at 25°C for 24 hours; B represents the adhesive retention force of the adhesive layer measured by peeling the base film of the protective film at 5 mm per second at a speed of 5 mm per second after the adhesive layer of the protective film is attached to the glass and aged at 25°C for 24 hours; C represents the adhesive retention force of the adhesive layer after the adhesive layer of the protective film is attached to the glass, aged at 25°C for 24 hours, and then peeled off the base film of the protective film at 60°C at a speed of 5mm per second in a 180° angle. The weight-average molecular weight of the fluorine-substituted polyurethane acrylate copolymer is 5,000 to 1,000,000. The fluorinated polyurethane acrylate copolymer comprises repeating units derived from hydroxyl-terminated perfluoropolyethers, wherein the hydroxyl-terminated... Perfluoropolyethers contain 4 to 10 fluorine molecules; The adhesive layer also contains acrylate monomers. The acrylate monomers include compounds represented by the following chemical formula 1, compounds represented by the following chemical formula 2, compounds represented by the following chemical formula 3, and isobornyl acrylate. [Chemical Formula 1] [Chemical Formula 2] [Chemical Formula 3] In the chemical formula 1, B1 is -CH2-, -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, or -CH2CH2CH2CH2CH2-, and R1 and R2 are independently C1-C12 straight-chain alkyl, C3-C12 branched alkyl, phenyl, or alkylphenyl groups, respectively. In the chemical formula 2, B3 is -CH2CH2-, -CH2CH2CH2-, -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, or -CH2CH2CH2CH2CH2CH2-. In the chemical formula 3, B2 is -CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2CH2-, -CH2CH2CH2CH2CH2CH2CH2-, or -CH2CH2CH2CH2CH2CH2CH2CH2-; The adhesive layer contains 0.5 to 1.5 parts by weight of photoinitiator and 0.1 to 0.4 parts by weight of antistatic agent.

2. The protective film for OLED panel manufacturing process according to claim 1, characterized in that, The adhesive layer, relative to 100 parts by weight of the main resin, comprises 1 to 10 parts by weight of the compound represented by chemical formula 1, 1 to 10 parts by weight of the compound represented by chemical formula 2, 1 to 10 parts by weight of the compound represented by chemical formula 3, and 15 to 35 parts by weight of isoborneol acrylate.

3. The protective film for OLED panel manufacturing process according to claim 1, characterized in that, The base film is a permanent antistatic film containing a permanent antistatic agent and a plastic resin.

4. The protective film for OLED panel manufacturing process according to claim 1, characterized in that, The base film and adhesive layer of the protective film have a thickness ratio of 1:0.13~0.

66.

5. The protective film for OLED panel manufacturing process according to claim 1, characterized in that, The protective film also satisfies conditions (6) and (7); (6) 0.8 ≤ A / W ≤ 1.5 (7) 0.8 ≤ A / Y ≤ 1.5 In conditions (6) and (7), A represents the adhesive force of the adhesive layer measured after the adhesive layer of the protective film is attached to the glass, aged at 25°C for 4 hours, and then peeled off at 25°C at a speed of 5 mm per second at 180°; W represents the adhesive holding force of the adhesive layer measured after the adhesive layer of the protective film is attached to the glass, aged at 25°C for 4 hours, and then peeled off at 0°C at a speed of 5 mm per second at 180°; Y represents the adhesive force of the adhesive layer measured after the adhesive layer of the protective film is attached to the glass, exposed at 0°C for 1000 hours, aged at 25°C for 4 hours, and then peeled off at 25°C at a speed of 5 mm per second at 180°.

6. The protective film for OLED panel manufacturing process according to claim 1, characterized in that, The protective film also satisfies conditions (8) and (9); (8) 0.4 ≤ A / H ≤ 1.5 (9) 0.4 ≤ A / Z ≤ 1.0 In conditions (8) and (9), A represents the adhesive strength of the adhesive layer measured after the adhesive layer of the protective film is attached to the glass, aged at 25°C for 4 hours, and then peeled off at 25°C at a speed of 5 mm per second at 180°; H represents the adhesive strength of the adhesive layer measured after the adhesive layer of the protective film is attached to the glass, aged at 25°C for 4 hours, exposed at -30°C for 500 hours, aged at 25°C for 4 hours, and then peeled off at 25°C at a speed of 5 mm per second at 180°; Z represents the adhesive strength of the adhesive layer measured after the adhesive layer of the protective film is attached to the glass, exposed at 60°C for 1000 hours, aged at 25°C for 4 hours, and then peeled off at 25°C at a speed of 5 mm per second at 180°.

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