Adhesive protective film, optical member comprising same, and optical display device comprising optical member

Abstract

The invention relates to an adhesive protective film, an optical member including the same, and an optical display device including the optical member. This adhesive protective film is used in a polyimide-based optical device containing polyimide ash. The adhesive protective film includes a cured product of a composition including: a (meth) acrylic copolymer; a curing agent; a (meth) acrylic oligomer; and a monofunctional or high-functional (meth) acrylic monomer containing an aromatic group, in which the adhesive protective film has a storage modulus of 0.1 MPa or less at-20 DEG C, a peel strength of 350 gf / inch or more at 60 DEG C and 93% RH (Relative Humidity) for a polyimide-based optical device containing polyimide ash, and a creep of 40% or less at 60 DEG C.

Description

[0001] CITATION OF RELATED APPLICATION

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2024-0116102, filed on August 28, 2024, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. TECHNICAL FIELD

[0003] The present disclosure relates to an adhesive protective film, an optical member, and an optical display apparatus. BACKGROUND

[0004] In devices in the related art, such as optical members or electronic members, a protective film composed of only an adhesive layer or a protective film composed of a base film and an adhesive layer is attached on a surface of the device to prevent scratches from being formed thereon during processes, such as machining, assembly, inspection, etc. Such a protective film is used by removing a release film from the adhesive layer. In recent years, as optical members, organic light emitting diode (OLED) devices have replaced liquid crystal devices. In addition, in the related art, flexible OLED devices are increasingly used.

[0005] Unlike liquid crystal devices or typical OLED devices, flexible OLED devices are highly flexible and thus require a process protective film to protect an OLED panel from being scratched on the surface during machining, assembly, inspection, etc. The process protective film needs to have low peeling strength and reworkability, so that it can be (e.g., easily) removed if a defect, such as an appearance abnormality or a foreign substance, is detected (or generated) during panel inspection. After panel inspection, a P film (patterned film) is permanently attached to the panel to support the panel while protecting the panel against moisture and / or the outside environment. Since the P film must be permanently attached to the panel, the P film is required to have high peeling strength and reliability.

[0006] Therefore, since the panel production method in the related art requires a low-peeling-strength process protective film for temporary use and a high-peeling-strength P film having high peeling strength, a method of process protective film attachment → process protective film removal → P film attachment is required.

[0007] In recent years, cost reduction and process optimization have been ongoing. Specifically, if (e.g., when) used as a process protective film before UV irradiation, the process protective film is patterned by laser. Herein, if (e.g., when) the initial peeling strength of the protective film is higher than a certain degree (e.g., a certain value) with respect to a polyimide substrate, there can be a problem of yield deterioration due to a decrease in peeling success rate. Therefore, it can be desirable to provide a protective adhesive film having low peeling strength if (e.g., when) stacked on a polyimide substrate and showing high peeling strength after UV irradiation to incorporate the process protective film into a P film.

[0008] Background Art SUMMARY

[0009] One aspect according to an embodiment of the present disclosure relates to an adhesive protective film that exhibits high adhesion to a polyimide-based optical device containing polyimide ash under high-temperature / high-humidity conditions.

[0010] One aspect according to an embodiment of the present disclosure relates to an adhesive protective film that exhibits good foldability.

[0011] One aspect according to an embodiment of the present disclosure relates to an adhesive protective film that exhibits good wettability to a polyimide-based optical device containing polyimide ash.

[0012] One aspect according to the present disclosure relates to an adhesive protective film for a polyimide-based optical device containing polyimide ash.

[0013] The adhesive protective film comprises a cured product of a composition comprising a (meth)acrylic copolymer, a curing agent, a (meth)acrylic oligomer, and a monofunctional or high-functional (meth)acrylic monomer containing an aromatic group, wherein the adhesive protective film has a storage modulus of 0.1 MPa or less at -20°C, a peel strength of 350 gf / inch or more to a polyimide-based optical device containing polyimide ash at 60°C and 93% relative humidity (RH), and a creep of 40% or less at 60°C.

[0014] Another aspect of the present disclosure relates to an optical member.

[0015] The optical member includes a polyimide-based optical device having at least one surface containing polyimide ash thereon, and an adhesive layer bonded to the at least one surface (i.e., the surface containing polyimide ash), wherein the adhesive layer includes an adhesive protective film.

[0016] Still another aspect of the present disclosure relates to an optical display device.

[0017] The optical display device includes an adhesive protective film or a cured product of an optical member.

[0018] An embodiment of the present disclosure provides an adhesive protective film that exhibits high peel strength to a polyimide-based optical device containing polyimide ash under high-temperature / high-humidity conditions.

[0019] An embodiment of the present disclosure provides an adhesive protective film that exhibits good foldability.

[0020] Embodiments of the present disclosure provide an adhesive protective film that exhibits good wettability for a polyimide-based optical device containing polyimide ash. BRIEF DESCRIPTION OF DRAWINGS

[0021] The above and other objects, features and advantages of the present disclosure will become more apparent to those skilled in the art from the following detailed description in conjunction with the accompanying drawings, in which:

[0022] Figure 1 is a schematic diagram of a method of forming a polyimide layer containing polyimide ash according to one or more embodiments of the present disclosure.

[0023] Figure 2 is a schematic diagram of a method of forming a polyimide layer containing polyimide ash according to one or more embodiments of the present disclosure.

[0024] Figure 3 is a schematic diagram showing a laser irradiation process during formation of a polyimide layer containing polyimide ash.

[0025] Figure 4 is a cross-sectional view of an optical member according to one or more embodiments.

[0026] Figure 5 is a graph showing an evaluation method of a simulated bubble portion.

[0027] Figure 6 Evaluation results of a simulated bubble portion are shown. DETAILED DESCRIPTION

[0028] Hereinafter, exemplary embodiments of the present disclosure will be described in greater detail by referring to the accompanying drawings, so that a person having an ordinary knowledge in the art can (for example, easily) implement the present disclosure. It should be understood that the present disclosure can be embodied in many different forms and should not be construed as being limited to the following embodiments.

[0029] The terminology used herein is for the purpose of describing exemplary embodiments only and is not intended to limit the present disclosure. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0030] Herein, the term "(meth)acryloyl" refers to acryloyl and / or methacryloyl.

[0031] Herein, the term "copolymer" can include a polymer or a resin.

[0032] In this document, the term "glass transition temperature" can refer to the glass transition temperature (Tg) of a target monomer or homopolymer measured using a differential scanning calorimeter (DSC, such as DSC Discovery from TA Instruments). For example, a homopolymer of the target monomer is heated to 180°C at a heating rate of 20°C / min, slowly cooled to -100°C, and then reheated to 100°C at a heating rate of 10°C / min (e.g., during a second heating process) to obtain endothermic transition curve data. The inflection point of the endothermic transition curve (e.g., obtained from the second heating process) can be defined as the glass transition temperature of the target monomer.

[0033] As used in this article to indicate a specific numerical range, "X to Y" means a value that is greater than or equal to X and less than or equal to Y (X ≤ and ≤ Y).

[0034] According to one or more embodiments, the adhesive protective film has a peel strength of 350 gf / inch or higher for polyimide optical devices containing polyimide ash at 60°C and 93% RH (relative humidity), a storage modulus of 0.1 MPa or lower at -20°C, and creep of 40% or lower at 60°C.

[0035] "Polyimide optical devices" refers to polymer films processed (e.g., produced) by polymerization of polyamic acid precursors containing imide and aryl groups in repeating units, possessing excellent mechanical and thermal properties, and usable as substrates for flexible OLED panels.

[0036] In one or more embodiments, polyimide optical devices may be provided in the form of a polyimide layer.

[0037] First, the method for forming a polyimide layer including a surface containing polyimide ash will be described in more detail.

[0038] Figure 1 This is a schematic diagram of a method for forming a polyimide layer containing polyimide ash according to one or more embodiments.

[0039] refer to Figure 1 In (1), polyimide varnish is deposited on the lower surface of glass plate 10 to a set or predetermined thickness to form polyimide varnish coating 11.

[0040] In (2), the polyimide varnish coating 11 is dried and cured to form a polyimide layer 12 on the lower surface of the glass plate 10.

[0041] In (3), the glass plate 10 is irradiated with a laser beam emitted from a laser irradiator 13 placed above the glass plate 10, and polyimide ash (e.g., residue or particles) 14 is formed on the upper surface of the polyimide layer 12.

[0042] Laser irradiation can form polyimide ash 14 by burning a portion of the polyimide layer 12. The polyimide ash can refer to fine (e.g., small) irregularities in the form of powder (e.g., residue or particles), which can form fine (e.g., small) steps between the laser-treated and non-laser-treated portions. These steps can help the glass plate to delaminate in step (4). The degree of polyimide ash formation and / or the area ratio of polyimide ash 14 (the ratio of the total area of ​​the polyimide ash to the total area of ​​the polyimide layer) can be adjusted according to the type or variety of the polyimide varnish, the total thickness of the polyimide layer, the degree of laser beam irradiation, etc.

[0043] In (4), the glass plate 10 can be removed from the polyimide layer 12, thereby providing a polyimide layer 15 including a surface containing polyimide ash 14.

[0044] Figure 2 This is a schematic diagram of a method for forming a polyimide layer containing polyimide ash according to one or more embodiments.

[0045] refer to Figure 2 In (1), a polyimide varnish is deposited on the upper surface of the release base film 16 to a set or predetermined thickness to form a polyimide varnish coating 11.

[0046] In (2), the polyimide varnish coating 11 is dried and cured to form a polyimide layer 12 on the upper surface of the release base film 16.

[0047] In (3), a glass plate 10 is arranged on the upper surface of the polyimide layer 12.

[0048] In (4), the glass plate 10 is irradiated with a laser beam emitted from a laser irradiator 13 positioned above the glass plate, forming polyimide ash (e.g., residue or particles) 14 on the upper surface of the polyimide layer 12. Laser treatment can form the polyimide ash by burning a portion of the polyimide layer 12. The polyimide ash can refer to fine (e.g., small) irregularities in the form of powder (e.g., residue or particles), which can form fine (e.g., small) steps between the laser-treated and non-laser-treated portions. These steps can help the glass plate to delaminate in step (5). The degree of polyimide ash formation 14 and / or the area ratio of the polyimide ash 14 (the ratio of the total area of ​​the polyimide ash to the total area of ​​the polyimide layer) can be adjusted according to the type or variety of the polyimide varnish, the total thickness of the polyimide layer, the degree of laser beam irradiation, etc.

[0049] In (5), the glass plate 10 can be removed from the polyimide layer 12, thereby providing a laminate of a polyimide layer 15 having polyimide ash 14 on its surface and a release base film 16.

[0050] The release base film 16 is demolded using silicone or the like, and can therefore be removed (e.g., easily).

[0051] Figure 3 This is a schematic diagram showing the laser irradiation process during the formation of a polyimide layer containing polyimide ash (e.g., residues or particles).

[0052] refer to Figure 3 A laminate is prepared in which a polyimide layer 12 and a glass plate 10 are sequentially stacked on the upper surface of a release base film 16. The laminate is then irradiated with a laser beam 18 from above the upper surface of the glass plate 10 using a laser irradiation device 13, forming polyimide ash 14 on the upper surface of the polyimide layer 12. The laminate is conveyed in a specific direction (arrow direction, e.g., from right to left), and by adjusting the switch of the laser irradiation, the polyimide ash 14 can be formed discontinuously on the upper surface of the polyimide layer 12.

[0053] The glass sheet is alkali-free and can have a thickness of 1mm to 2mm.

[0054] Polyimide varnishes may include, but are not limited to, 90 wt% or more of at least one selected from polyimide copolymers, polyimide oligomers, and polyimide monomers. For example, polyimide varnishes may include, but are not limited to, SD Flex (DuPont).

[0055] Polyimide varnish can be deposited by any suitable method (e.g., typical methods known to those skilled in the art). For example, polyimide varnish can be deposited by blade coating. In this method, the coater can have a diameter of 0.5 mm to 1.0 mm, for example, 0.65 mm. The polyimide varnish can be deposited to a thickness of 20 μm to 30 μm.

[0056] It can dry and cure the polyimide varnish coating to form a polyimide layer.

[0057] Drying may include heat treatment at 50°C to 200°C for 5 to 60 minutes. For drying, the heat treatment may be performed once or more, for example, twice or more. In one or more embodiments, the heat treatment may be performed twice or more. For example, drying may include an initial heat treatment at 50°C to 100°C for 5 to 30 minutes, and a secondary heat treatment at 100°C to 200°C for 5 to 30 minutes. For example, the initial heat treatment may be performed at 80°C for 10 minutes, and the secondary heat treatment at 120°C for 20 minutes.

[0058] The dried product of polyimide varnish coating can have a thickness of 20 μm to 30 μm, for example, 20 μm.

[0059] Curing may include heat treatment at a higher temperature for a longer period than drying. This heat treatment can form a polyimide layer through imidization of the dried product of the polyimide varnish coating. The heat treatment may include heat treatment at a temperature greater than 200°C and less than or equal to 400°C for 30 to 120 minutes. In one or more embodiments, the heat treatment may be performed once or more. For example, curing includes heat treatment at 250°C for 60 minutes.

[0060] The polyimide layer can have a thickness of 20 μm to 30 μm, for example, 20 μm.

[0061] Laser irradiation can include 100 mJ / cm 2 Up to 500mJ / cm 2 For example, 150mJ / cm 2 Up to 200mJ / cm 2 The dose of irradiation. Within these ranges, polyimide ash that can be (e.g., easily) peeled off from a glass plate can be formed. Laser irradiation can include irradiation with light at a wavelength of 308 nm, and can include irradiation at picosecond, nanosecond, or femtosecond wavelengths.

[0062] Adhesive protective films exhibit a peel strength of 350 gf / inch or higher at 60°C and 93% RH for polyimide optics containing polyimide ash, thus contributing to good foldability when (e.g., when) attached to polyimide optics containing polyimide ash. For example, adhesive protective films can have a peel strength ranging from 350 gf / inch to 600 gf / inch at 60°C and 93% RH.

[0063] The adhesive protective film has a storage modulus of 0.1 MPa or lower at -20°C. Within this range, if (e.g., when) attached to polyimide optical devices containing polyimide ash, the adhesive protective film can help provide good foldability. For example, the adhesive protective film can have a storage modulus of 0.03 MPa to 0.1 MPa at -20°C.

[0064] The adhesive protective film exhibits 40% or less creep at 60°C. Within this range, if (e.g., when) attached to polyimide optical devices containing polyimide ash, the adhesive protective film can contribute to providing good foldability. For example, the adhesive protective film can exhibit creep from 15% to 40% at 60°C.

[0065] The adhesive protective film has 3.5% or less of simulated air bubbles. Within this range, the adhesive protective film can help provide good foldability when (e.g., when) attached to polyimide optical devices containing polyimide ash.

[0066] To achieve the aforementioned peel strength, modulus, creep, and simulated bubble portions, the adhesive protective film comprises a cured product of a composition containing (meth)acrylic copolymers, a curing agent, (meth)acrylic oligomers, and monofunctional or hyperfunctional (meth)acrylic monomers containing aromatic groups.

[0067] In one or more embodiments, the adhesive protective film may comprise a (meth)acrylic copolymer, a curing agent, a (meth)acrylic oligomer, and a monofunctional or hyperfunctional (meth)acrylic monomer containing an aromatic group. These components may be derived from the composition. In one or more embodiments, the adhesive protective film may comprise a (meth)acrylic copolymer and one or more selected from a curing agent, a (meth)acrylic oligomer, and a monofunctional or hyperfunctional (meth)acrylic monomer containing an aromatic group. These components may be derived from the composition.

[0068] In one or more embodiments, the curing agent may be a thermosetting product. For example, the curing agent may be a thermosetting agent suitable for thermosetting.

[0069] Each component of the composition will be described in more detail below.

[0070] (meth)acrylic acid copolymers

[0071] (Meth)acrylic copolymers are used as the matrix to form the adhesive protective film, and can be cured with isocyanate curing agents to ensure the peel strength of the adhesive protective film.

[0072] (Meth)acrylic copolymers can have glass transition temperatures (Tg) of -10°C or lower, for example, -80°C to -20°C. Within these ranges, (meth)acrylic copolymers can help provide suitable wettability (adhesion) and suitable initial peel strength of the adhesive protective film to polyimide optical devices.

[0073] (Meth)acrylic copolymers can be copolymers of monomer mixtures containing (meth)acrylic monomers having a homopolymer glass transition temperature of 60°C or lower and (meth)acrylic monomers having crosslinking functional groups, such as hydroxyl-containing (meth)acrylic monomers.

[0074] In one or more embodiments, (meth)acrylic monomers having a homopolymer glass transition temperature of 60°C or lower and (meth)acrylic monomers having crosslinking functional groups may be present in the monomer mixture in an amount of 95 wt% or higher, for example, 99 wt% to 100 wt%, or 100 wt%.

[0075] For example, (meth)acrylic monomers having a homopolymer glass transition temperature of 60°C or lower can have a homopolymer glass transition temperature ranging from -80°C to 60°C. Within this range, the adhesive protective film can (e.g., easily) achieve its effect.

[0076] (Meth)acrylic monomers having a homopolymer glass transition temperature of 60°C or lower may be present in amounts of 80 wt% or higher, for example, 80 wt% to 99 wt%, 80 wt% to 95 wt%, or 85 wt% to 99 wt%.

[0077] (Meth)acrylic monomers having a homopolymer glass transition temperature of 60°C or lower can be a mixture of two or more (meth)acrylic monomers having different homopolymer glass transition temperatures.

[0078] In one or more embodiments, the (meth)acrylic monomer having a homopolymer glass transition temperature of 60°C or lower can be a mixture of a (meth)acrylic monomer having a homopolymer glass transition temperature of -80°C to -20°C, for example -70°C to -55°C (referred to as the first monomer for convenience) and a (meth)acrylic monomer having a homopolymer glass transition temperature of -80°C to -20°C, for example -60°C to -40°C (referred to as the second monomer for convenience).

[0079] In one or more embodiments, the (meth)acrylic monomer having a homopolymer glass transition temperature of 60°C or lower can be a linear C1 to C2 monomer. 20 Alkyl (meth)acrylates and those with branched C1 to C2 chains 20 A mixture of alkyl (meth)acrylates.

[0080] In one or more embodiments, there are straight chains C1 to C 20 Alkyl (meth)acrylates and those with branched C1 to C2 chains 20 Each of the alkyl (meth)acrylates may be selected from the following having C1 to C1. 20 Alkyl (meth)acrylates. For example, those having a straight chain from C1 to C2. 20 Alkyl (meth)acrylates may include n-propyl (meth)acrylate, n-butyl (meth)acrylate, etc. They have branched chains from C1 to C2. 20 Alkyl (meth)acrylates may include 2-ethylhexyl (meth)acrylate, etc.

[0081] In one or more embodiments, there are straight chains C1 to C 20 Alkyl (meth)acrylates may be present in the monomer mixture in amounts from 5 wt% to 50 wt%, for example, from 5 wt% to 45 wt%, or from 10 wt% to 40 wt%. Branched C1 to C2 acrylates are also present. 20 Alkyl (meth)acrylates may be present in the monomer mixture in amounts ranging from 50 wt% to 90 wt%, for example, from 50 wt% to 80 wt%. Within these ranges, the adhesive protective film can (e.g., readily) achieve its effect.

[0082] Hydroxyl (meth)acrylate monomers can be (meth)acrylates containing at least one hydroxyl group. For example, hydroxy (meth)acrylates can include at least one selected from the following: 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, hydroxyhexyl (meth)acrylate, 1,4-cyclohexanediethanol mono(meth)acrylate, 1-chloro-2-hydroxypropyl (meth)acrylate, diethylene glycol mono(meth)acrylate, 1,6-hexanediol mono(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, neopentyl glycol mono(meth)acrylate, trimethylolpropane di(meth)acrylate, trimethylolethane di(meth)acrylate, 2-hydroxy-3-phenoxypropyl (meth)acrylate, 4-hydroxycyclopentyl (meth)acrylate, 4-hydroxycyclohexyl (meth)acrylate, and cyclohexanediethanol mono(meth)acrylate.

[0083] Hydroxy(meth)acrylic monomers may be present in the monomer mixture in amounts from 0.1 wt% to 20 wt%, such as 1 wt% to 20 wt%, 5 wt% to 20 wt%, or 0.5 wt% to 15 wt%. Within these ranges, hydroxy(meth)acrylic monomers can effectively impart cohesion to the adhesive layer to form the adhesive layer and can effectively provide initial peel strength to the adhesive protective film.

[0084] In one or more embodiments, the monomer mixture may be free of aromatic monomers. Adhesive protective films prepared from (meth)acrylic copolymers formed from aromatic monomers are unlikely to achieve the effects of the adhesive protective films according to this disclosure.

[0085] In one or more embodiments, (meth)acrylic monomers and hydroxyl-containing (meth)acrylic monomers having a homopolymer glass transition temperature of 60°C or lower may be present in the monomer mixture in an amount of 99 wt% or higher, for example, from 99 wt% to 100 wt%, or 100 wt%.

[0086] (Meth)acrylic acid copolymers can be prepared by polymerizing the monomer mixture using suitable (e.g., typical) polymerization methods. The polymerization method can include any suitable method (e.g., typical methods known to those skilled in the art). For example, (meth)acrylic acid copolymers can be prepared by adding an initiator to the monomer mixture and then copolymerizing it using suitable (e.g., typical) copolymerization methods, such as suspension polymerization, emulsion polymerization, solution polymerization, etc. The polymerization reaction can be carried out at a temperature of 60°C to 70°C for 4 to 8 hours. The initiator can be selected from suitable (e.g., typical) initiators, including azo-based polymerization initiators and / or peroxides, such as benzoyl peroxide or acetyl peroxide.

[0087] (meth)acrylic acid oligomers

[0088] (Meth)acrylic acid oligomers have a glass transition temperature of 60°C or lower and a weight-average molecular weight of 100,000 g / mol or lower. Within this range of glass transition temperature and weight-average molecular weight, (meth)acrylic acid oligomers can provide good foldability at room temperature and under high temperature / high humidity conditions.

[0089] For example, (meth)acrylic acid oligomers can have a glass transition temperature of -10°C to 60°C, such as 0°C to 30°C. For example, (meth)acrylic acid oligomers can have a weight-average molecular weight of 10,000 g / mol to 100,000 g / mol, such as 20,000 g / mol to 50,000 g / mol.

[0090] (Meth)acrylic acid oligomers can be prepared from suitable monomers (e.g., some monomers selected from monomers known to those skilled in the art) to provide glass transition temperatures and weight-average molecular weights within the ranges described above.

[0091] In one or more embodiments, the monomer mixture may include (meth)acrylic acid monomers having hydroxyl groups.

[0092] (Meth)acrylic monomers having hydroxyl groups may include at least one selected from the following: C1 to C2 groups containing hydroxyl groups. 20 Alkyl (meth)acrylic acid monomers, containing C3 to C4 groups with hydroxyl groups. 20 cycloalkyl (meth)acrylic acid monomers and C6 to C6 monomers containing hydroxyl groups 20 Aryl (meth)acrylic monomers. For example, hydroxyl-containing (meth)acrylic monomers may include at least one selected from the following: 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 6-hydroxyhexyl (meth)acrylate as C1 to C2 groups containing hydroxyl groups. 20 Alkyl (meth)acrylic acid monomers. These monomers can be used alone or as mixtures thereof.

[0093] Hydroxyl-containing (meth)acrylic monomers may be present in the monomer mixture in amounts from 2 wt% to 5 wt%, for example, greater than 2 wt% and less than or equal to 5 wt%. Within these ranges, the adhesive protective film can (e.g., readily) achieve its effect.

[0094] In addition to (meth)acrylic acid monomers having hydroxyl groups, the monomer mixture may also contain (meth)acrylic acid monomers having alkyl groups.

[0095] Alkyl (meth)acrylic monomers may have straight or branched C1 to C2 chains at their ester sites. 20 Alkyl (meth)acrylates. For example, (meth)acrylates may include at least one selected from the following: butyl (meth)acrylate (e.g., n-butyl (meth)acrylate), pentyl (meth)acrylate (e.g., n-pentyl (meth)acrylate), hexyl (meth)acrylate (e.g., n-hexyl (meth)acrylate), heptyl (meth)acrylate (e.g., n-heptyl (meth)acrylate), octyl (meth)acrylate (e.g., n-octyl (meth)acrylate), 2-ethylhexyl (meth)acrylate, nonyl (meth)acrylate (e.g., n-nonyl (meth)acrylate), and decyl (meth)acrylate (e.g., n-decyl (meth)acrylate).

[0096] Alkyl (meth)acrylic monomers may be present in the monomer mixture in amounts ranging from 40 wt% to 60 wt%. Within this range, alkyl (meth)acrylic monomers can ensure the peel strength and suitable modulus of the adhesive film.

[0097] In addition to hydroxyl-containing (meth)acrylic monomers and alkyl-containing (meth)acrylic monomers, the monomer mixture may also contain comonomers that are copolymerizable with it.

[0098] In one or more embodiments, (meth)acrylic acid oligomers can be prepared by polymerization of a monomer mixture using a suitable (e.g., typical) polymerization method. The polymerization method can include any suitable method (e.g., typical methods known to those skilled in the art). For example, (meth)acrylic acid oligomers can be prepared by adding an initiator to a monomer mixture and then copolymerizing it using a suitable (e.g., typical) copolymerization, such as suspension polymerization, emulsion polymerization, solution polymerization, etc. The polymerization reaction can be carried out at a temperature of 65°C to 70°C for 6 to 8 hours. The initiator can be selected from suitable (e.g., typical) initiators, including azo-based polymerization initiators and / or peroxides, such as benzoyl peroxide or acetyl peroxide.

[0099] (Meth)acrylic oligomers may be present in amounts of 0.1 to 3 parts by weight, for example 0.5 to 2 parts by weight, or 0.5 to 1 part by weight, relative to 100 parts by weight of (meth)acrylic copolymer. Within these ranges, the adhesive film can (e.g., readily) achieve its effect.

[0100] Monofunctional or highly functional (meth)acrylic acid monomers containing aromatic groups

[0101] Monofunctional or highly functional (meth)acrylic acid monomers containing aromatic groups have at least one functional group capable of reacting with an aryl group via an initiator. In this document, the aryl group can represent C6 to C6. 50 Monocyclic or polycyclic functional groups. For example, aryl can represent substituted or unsubstituted benzyl, phenyl, biphenyl, terphenyl, or naphthyl, etc. In addition, "functional group" can represent vinyl or (meth)acrylate group.

[0102] Monofunctional or highly functional (meth)acrylic monomers containing aromatic groups can improve the adhesion between the adhesive protective film and the substrate, such as aryl plastic films, like polyimide films, by increasing the attractiveness of the adhesive layer of the adhesive protective film to the substrate through a stacking effect of π-π bonds with the substrate.

[0103] Monofunctional or highly functional (meth)acrylic monomers containing aromatic groups can improve the cohesion and / or modulus of adhesive protective films.

[0104] It is desirable that the glass transition temperature of homopolymers of monofunctional or hyperfunctional (meth)acrylic acid monomers containing aromatic groups is within a set or predetermined range relative to the glass transition temperature of (meth)acrylic acid copolymers. Even when the adhesive protective film is cured (e.g.), this condition improves the peel strength of the adhesive protective film by suppressing its shrinkage.

[0105] Homopolymers of monofunctional or hyperfunctional (meth)acrylic acid monomers containing aromatic groups have higher glass transition temperatures than (meth)acrylic acid copolymers, and the difference can be 20°C or higher, for example, 20°C to 120°C, or 40°C to 100°C. Within these ranges, adhesive protective films can ensure good wettability for polyimide optical devices.

[0106] Monofunctional or polyfunctional (meth)acrylic monomers containing aromatic groups can have a glass transition temperature of -30°C or higher, for example, -30°C to 50°C for homopolymers. Within these ranges, monofunctional or polyfunctional (meth)acrylic monomers containing aromatic groups have a higher glass transition temperature than (meth)acrylic copolymers, thereby improving the peel strength of the adhesive protective film by improving cohesion.

[0107] Monofunctional or highly functional (meth)acrylic acid monomers containing aromatic groups may include, but are not limited to, compounds represented by Formula 1:

[0108]

[0109] Where R 1 It is hydrogen or methyl;

[0110] s is an integer selected from 0 to 10;

[0111] R 2 It is substituted or unsubstituted C6 to C 50 aryl or substituted or unsubstituted C6 to C 50 aryloxy groups; and

[0112] T is a substituted or unsubstituted C1 to C6 alkylene group or a substituted or unsubstituted C1 to C6 alkylene group.

[0113] As used herein, the term "substituted" in the phrase "substituted or unsubstituted" means that at least one hydrogen atom of the corresponding functional group is substituted by C1 to C2. 10 Alkyl, C1 to C 10 thioalkyl, C1 to C 10 Alkoxy groups, halogens (F, Cl, Br, or I), C3 to C4 10 cycloalkyl or C6 to C 20 Aryl substitution.

[0114] For example, R 2 It can be substituted or unsubstituted phenoxy, benzyl, phenyl, biphenyl, terphenyl, naphthyl, etc. For example, monofunctional or highly functional monomers containing aromatic groups may include at least one selected from the following (e.g., selected from the group consisting of): phenoxy(meth)acrylate, benzyl phenoxy(meth)acrylate, phenoxy polyethylene glycol (meth)acrylate, 2-ethylphenoxy(meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, 2-ethylphenylthio(meth)acrylate, 2-phenylethyl(meth)acrylate, 3-phenylpropyl(meth)acrylate, 4-phenylbutyl(meth)acrylate, ethyl 2-(2-methylphenyl)(meth)acrylate, ethyl 2-(3-methylphenyl)(meth)acrylate, ethyl 2-(4-methylphenyl)(meth)acrylate, ethyl 2-(4-propylphenyl)(meth)acrylate, ethyl 2-(4-(1-methylethyl)phenyl)(meth)acrylate, ethyl 2-(4-methoxyphenyl)(meth)acrylate, ethyl 2-(4-cyclohexylphenyl)(meth)acrylate, ethyl 2-(2-chlorophenyl)(meth)acrylate. Ethyl acrylate, 2-(3-chlorophenyl)(meth)acrylate, 2-(4-chlorophenyl)(meth)acrylate, 2-(4-bromophenyl)(meth)acrylate, 2-(3-phenylphenyl)(meth)acrylate, o-phenyl(meth)acrylate, m-phenyl(meth)acrylate, p-phenyl(meth)acrylate, 2,6-terphenyl(meth)acrylate, o-terphenyl(meth)acrylate, m-terphenyl(meth)acrylate, p-terphenyl(meth)acrylate 4-(4-methylphenyl)(methyl)phenyl acrylate, 4-(2-methylphenyl)(methyl)phenyl acrylate, 2-(4-methylphenyl)(methyl)phenyl acrylate, 2-(2-methylphenyl)(methyl)phenyl acrylate, 4-(4-ethylphenyl)(methyl)phenyl acrylate, 4-(2-ethylphenyl)(methyl)phenyl acrylate, 2-(4-ethylphenyl)(methyl)phenyl acrylate, 2-(2-ethylphenyl)(methyl)phenyl acrylate and mixtures thereof.

[0115] For example, monofunctional or hyperfunctional (meth)acrylate monomers containing aromatic groups include at least one of benzyl phenoxy (meth)acrylate or phenoxy polyethylene glycol (meth)acrylate.

[0116] Monofunctional or highly functional (meth)acrylic monomers containing aromatic groups may be present in amounts greater than 0 parts by weight and less than or equal to 10 parts by weight relative to 100 parts by weight of the (meth)acrylic copolymer, for example, from 0.1 parts by weight to 10 parts by weight, from 1 part by weight to 5 parts by weight, or from 1 part by weight to 3 parts by weight. Within these ranges, monofunctional or highly functional (meth)acrylic monomers containing aromatic groups can help improve the peel strength of the adhesive protective film while inhibiting the shrinkage of the adhesive protective film.

[0117] thermosetting agent

[0118] Thermosetting agents can cure (meth)acrylic copolymers and (meth)acrylic oligomers to help form the matrix of the adhesive film, while improving the peel strength of the adhesive film.

[0119] The thermosetting agent may include at least one selected from the following: isocyanate curing agent, metal chelate curing agent, epoxy curing agent, amine curing agent and aziridine curing agent.

[0120] Isocyanate curing agents may include difunctional to hexafunctional isocyanate curing agents. For example, isocyanate curing agents may include at least one aromatic isocyanate curing agent selected from toluene diisocyanate, phenyl diisocyanate, halogen-substituted toluene diisocyanate, phenylene diisocyanate, including m-phenylene diisocyanate and tetramethyl-phenyl diisocyanate, at least one aliphatic isocyanate curing agent selected from hexamethylene diisocyanate and pentamethylene diisocyanate, and / or at least one alicyclic isocyanate curing agent, such as cyclohexamethylene diisocyanate, or at least one adduct thereof, such as a polyol, such as trimethylolpropane (TMP), and / or an adduct of the curing agents described above.

[0121] Metal chelating curing agents are crosslinking agents comprising a metal and chelating bonds (e.g., composed of a metal and chelating bonds) and may include any suitable metal chelating crosslinking agent (e.g., typical metal chelating crosslinking agents known to those skilled in the art). In one or more embodiments, the metal chelating crosslinking agent may include a crosslinking agent having at least two, for example, three to six chelating bonds with a metal. For example, the metal may include aluminum, zirconium, titanium, and / or cobalt. For example, the metal may include aluminum. For example, the chelate may include, but is not limited to, acetylacetonate, ethyl acetoacetate, etc. For example, the metal chelating crosslinking agent may include, but is not limited to, at least one selected from: aluminate acetylacetonate, trialuminum (acetylacetonate), trialuminum (ethyl acetoacetate), bis(acetoacetate)aluminum, trizirconium (acetylacetonate), and tricobalt (acetylacetonate).

[0122] The thermosetting agent may be present in an amount of 0.01 parts by weight to 1 part by weight, for example, 0.01 parts by weight to 0.5 parts by weight, 0.01 parts by weight to 0.3 parts by weight, or 0.2 parts by weight to 0.3 parts by weight, relative to 100 parts by weight of (meth)acrylic adhesive. Within these ranges, the thermosetting agent can ensure improvements in the peel strength, shear strain, and storage modulus of the adhesive film.

[0123] The adhesive composition may also include a curing accelerator.

[0124] Curing accelerators can aid in the curing reaction of the adhesive protective film to further improve the cohesion of the adhesive layer. Curing accelerators can include suitable curing accelerators (e.g., typical curing accelerators known to those skilled in the art). Curing accelerators can include tin-based metal compounds, zinc-based metal compounds, amine compounds, titanium-based metal compounds, bismuth-based metal compounds, and aluminum-based metal compounds. In one or more embodiments, tin-based metal compounds are used. For example, tin-based metal compounds can include tetravalent or divalent organotin compounds, such as dibutyltin dilaurate, dibutyltin diacetylacetonate, dibutyltin hydrogen dimaleate, etc.

[0125] The curing accelerator may be present in an amount of 0.001 parts by weight to 3 parts by weight relative to 100 parts by weight of the (meth)acrylic copolymer. Within this range, the curing accelerator can help accelerate the curing of the adhesive protective film while improving the cohesion of the adhesive film.

[0126] The adhesive composition may also include a silane coupling agent.

[0127] Silane coupling agents can further improve the peel strength of the adhesive protective film. Silane coupling agents can include suitable silane coupling agents (e.g., typical silane coupling agents known to those skilled in the art). For example, silane coupling agents can include, but are not limited to, epoxy-containing silane coupling agents such as glycidylpropoxytrimethoxysilane, methacryloxypropylmethyldimethoxysilane, etc.

[0128] The silane coupling agent can be present in an amount of 0.01 parts by weight to 5 parts by weight relative to 100 parts by weight of the (meth)acrylic copolymer. Within this range, the silane coupling agent can further improve the peel strength of the adhesive protective film.

[0129] The adhesive composition may also include additives. Additives may include suitable additives (e.g., typical additives for adhesive protective films known to those skilled in the art). For example, the additives may include, but are not limited to, at least one selected from: pigments, UV absorbers, antioxidants, leveling agents, antistatic agents, retarders, catalysts, and rework agents.

[0130] The adhesive composition may also include a solvent. The solvent is used to improve the coatability of the adhesive composition to form an adhesive protective film with a thin thickness and a uniform surface. The solvent may include suitable solvents (e.g., typical types of solvents known to those skilled in the art). For example, the solvent may include, but is not limited to, methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, toluene, etc. In one or more embodiments, the adhesive composition may have a solids content of 15 wt% to 40 wt%, for example, 20 wt% to 30 wt%, with respect to the solids content of the adhesive protective film. Within these ranges, the composition may have good coatability.

[0131] Adhesive protective films can have a haze of 5% or less, such as 0.1% to 2%, in the visible spectrum (e.g., at wavelengths from 380 nm to 780 nm), and a total transmittance of 80% or more, such as 85% to 95%. Within these ranges, adhesive protective films can have good optical transparency and can be used in optical display devices.

[0132] The adhesive protective film can have an adhesive layer thickness of 200 μm or less, for example, greater than 0 μm to less than or equal to 100 μm, or 5 μm to 50 μm. Within these ranges, the adhesive protective film can help provide protection for flexible panels.

[0133] The adhesive protective film may also include a base film located on one of its surfaces (e.g., the first surface).

[0134] The adhesive protective film may also include a release film located on its other surface (e.g., a second surface opposite the first surface).

[0135] Another aspect of this disclosure relates to optical components.

[0136] The optical component includes a polyimide optical device having at least one surface thereon containing polyimide ash, and an adhesive layer bonded to the surface containing polyimide ash, wherein the adhesive layer includes a photocured product of an adhesive protective film.

[0137] In one or more embodiments, the polyimide optical device can be a flexible substrate. The flexible substrate can be used to support the optical device, such as an organic light-emitting diode.

[0138] Suitable (e.g., typical) optical devices can be further stacked on at least one surface of a polyimide-based optical device. Such optical devices can provide conductivity and / or optical functions for optical display devices, such as light emission, polarization, optical compensation, and / or display quality improvement. For example, optical devices may include OLED devices, window films, windows, polarizing plates, color filters, retardation films, elliptical polarizing films, reflective polarizing films, antireflective films, compensation films, brightness enhancement films, alignment films, light diffusion films, shatterproof glass films, surface protective films, OLED device shielding layers, plastic LCD substrates, and transparent electrode films, including indium tin oxide (ITO), fluorinated tin oxide (FTO), aluminum-doped zinc oxide (AZO), carbon nanotubes (CNTs), Ag nanowires, or graphene, etc.

[0139] The adhesive layer includes a photocured product of the adhesive protective film. The adhesive protective film is essentially the same as the adhesive protective film described above.

[0140] In one or more embodiments, the adhesive layer may be patterned.

[0141] The protective layer may be further stacked on at least one surface of the adhesive layer.

[0142] The protective layer can protect the adhesive layer or polyimide optical devices. The protective layer is not limited to a specific type, as long as it is optically transparent and provides flexibility. For example, the protective layer can include polyester films, including polyethylene terephthalate films, polyethylene naphthalate films, polycarbonate films, polyethersulfone films, etc.

[0143] Figure 4 This is a cross-sectional view of an optical component according to one or more embodiments. Reference Figure 4 The optical component may include a polyimide optical device 15 having polyimide ash on its lower surface, an optical device 20 formed on the upper surface of the polyimide optical device 15, and an adhesive layer 33 formed on the lower surface of the polyimide optical device 15.

[0144] Other aspects of this disclosure relate to optical display devices.

[0145] Optical display devices include cured products of adhesive protective films or optical components. These cured products may be photocurable products.

[0146] Optical display devices can include organic light-emitting diode displays, liquid crystal displays, etc. Optical display devices can also include flexible display devices. However, optical display devices can also include non-flexible display devices.

[0147] The present disclosure will then be described in more detail with reference to some embodiments. However, it should be understood that these embodiments are provided for illustrative purposes only and should not be construed as limiting the present disclosure in any way.

[0148] Example 1

[0149] A solvent (ethyl acetate) was added to a 1 L reactor configured to allow reflux with nitrogen and equipped with a cooling system to aid temperature control. 100 parts by weight of a monomer mixture comprising 55 wt% 2-ethylhexyl acrylate (2-EHA), 40 wt% n-butyl acrylate (n-BA), and 4 wt% 4-hydroxybutyl acrylate (4-HBA) was added to the reactor. Nitrogen was introduced into the monomer mixture for 30 min to remove oxygen, and the reactor temperature was maintained at 62 °C. While the monomer mixture was being uniformly stirred, 0.07 wt% of an initiator (azobisisobutyronitrile) was added to the monomer mixture, and the reaction was carried out at 62 °C for 8 h to prepare a (meth)acrylic acid copolymer (glass transition temperature: -60 °C, weight average molecular weight: 600,000 g / mol). A (meth)acrylic acid copolymer solution (solids content: 24 wt%) was prepared by adding ethyl acetate as a solvent to the resulting product.

[0150] Preparation of adhesive protective film

[0151] An adhesive composition for adhesive films (solids content: 25 wt%) was prepared by mixing 100 parts by weight of the prepared (meth)acrylic copolymer, 1 part by weight of the (meth)acrylic oligomer (prepared from a monomer mixture comprising 5 wt% of hydroxyl-containing (meth)acrylic monomers having a weight-average molecular weight of 30,000 g / mol and a glass transition temperature of 30 °C), 0.23 parts by weight of the isocyanate curing agent (Coronate-L, TOSOH), and 1 part by weight of phenoxybenzyl acrylate (PBA).

[0152] The prepared adhesive composition was deposited to a thickness of 25 μm on the antistatic coating surface of the base film (polyethylene terephthalate (PET) film, T914J75, thickness: 50 μm, antistatic layer coated on one surface, MCC), and dried at 110 °C for 4 min to form an adhesive layer. Then, a release film (thickness: 50 μm, silicone release treatment on one surface, MHF50, MCC) was bonded to the adhesive layer and held at 60 °C for 3 days to prepare a sheet containing an adhesive protective film, wherein the adhesive protective film (thickness: 25 μm) and the release film are sequentially stacked on the base film.

[0153] Examples 2 to 4

[0154] Sheets containing an adhesive protective film were prepared in the same manner as in Example 1, except that, as shown in Table 1, the type and / or content of each component in Example 1 were changed.

[0155] Comparative Examples 1 to 5

[0156] Sheets containing adhesive protective films were prepared in the same manner as in Example 1, except that, as shown in Table 1, the type and / or content of each component in Example 1 were changed.

[0157] The sheets containing the adhesive protective film prepared in the following examples and comparative examples were evaluated for the following properties, and the evaluation results are shown in Table 1.

[0158] Reference Example: Preparation of a Polyimide Layer Containing Polyimide Ash on One Surface A polyimide layer containing polyimide ash on one surface was prepared.

[0159] A polyimide varnish (SD Flex, DuPont) coating was prepared by depositing it to a thickness of 20 μm on the upper surface of an alkali-free glass plate (thickness: 1.1 mm) using a doctor blade coating device (coater diameter: 0.65 mm).

[0160] The polyimide varnish coating was heat-treated at 80°C for 10 min and then at 120°C for 20 min to prepare a dried film of the polyimide varnish coating (thickness: 20 μm).

[0161] A laminate of a polyimide layer (thickness: 20 μm) and a glass plate was prepared by curing a dried polyimide varnish layer in a room at 250 °C for 60 min.

[0162] A laser beam was used to irradiate the laminate while simultaneously moving a laser irradiation device (MicroLAS, COHERENT) positioned above a glass plate of the laminate from one side to the other. The wavelength was 308 nm, the time was femtosecond, and the dose was 170 mJ / cm². 2 Laser irradiation is performed under specific conditions.

[0163] After the laminate is kept at room temperature for 1 hour, a polyimide layer containing polyimide ash is prepared on one surface by removing the glass plate.

[0164] (1) Energy storage modulus (unit: MPa):

[0165] The adhesive protective films prepared in each of the examples and comparative examples were stacked to a thickness of 800 μm, and the storage modulus was measured at -20°C using DHR3 under conditions of 1.0 N axial force, 0.1 N sensitivity, and 1.0 Hz frequency.

[0166] (2) Creep (unit: %)

[0167] The adhesive protective films produced in the examples and comparative examples were stacked to a thickness of 800 μm, and creep was measured at 60°C using DHR3 under conditions of 1.0 N axial force, 0.1 N sensitivity, and 1.0 Hz frequency.

[0168] (3) Peel strength under high temperature / high humidity conditions (unit: gf / inch)

[0169] The release film was peeled off from each sheet containing the adhesive protective film according to the examples and comparative examples to expose the adhesive protective film. The exposed surface of the adhesive protective film was attached to the polyimide layer containing polyimide ash. The resulting product was then extruded under a 1 kg load roller, and the extruded product was cut into 25 mm × 100 mm (width × length) dimensions to prepare a sample. This sample was a laminate of PET film, adhesive protective film, and polyimide layer containing polyimide ash.

[0170] The sample was held at 23°C and 50% RH (relative humidity) for 30 min. The peel strength of the adhesive protective film was measured using a peel strength tester (Instron Inc.) at 23°C and 50% RH, under the conditions of peel temperature: 60°C, peel speed: 300 mm / min, and peel angle: 180°, when the adhesive protective film was peeled from a surface containing polyimide ash.

[0171] (4) Simulated bubble portion (unit: %)

[0172] refer to Figure 5 and Figure 6 The simulated bubble portion was evaluated. A sheet containing the adhesive protective film was cut into rectangles of predetermined length and width. Then, a polyimide (PI) film was placed on a glass plate, and the protective film was peeled off from the sheet. Conversely, the exposed adhesive side portions were then attached to the polyimide film to prepare a sample, as shown below. Figure 5 As shown.

[0173] Then, by placing the laminate of the adhesive protective film and the base film on the polyimide film side, the ratio of the bubble area to the total area of ​​the polyimide film is calculated. The bubble area is evaluated using an image analyzer.

[0174] Table 1

[0175]

[0176] In Table 1,

[0177] PBA: Phenoxybenzyl acrylate (homopolymer Tg: 6℃) represented by the following chemical formula:

[0178]

[0179] PHEA-2: Phenooxy polyethylene glycol acrylate (homopolymer Tg: -13℃) represented by the chemical formula:

[0180]

[0181] ACMO: Acryloylmorpholine (aromatic-free, homopolymer Tg: 145℃).

[0182] As shown in Table 1, the adhesive protective film according to this disclosure exhibits high adhesive strength, good foldability, and good wettability for polyimide optical devices containing polyimide ash under high temperature / high humidity conditions.

[0183] Some embodiments of this disclosure provide adhesive protective films comprising thermosetting products of compositions including (meth)acrylic copolymers, curing agents, (meth)acrylic oligomers, and monofunctional or hyperfunctional (meth)acrylic monomers containing aromatic groups. The adhesive protective film has a storage modulus of 0.1 MPa or less at -20°C, a peel strength of 350 gf / inch or higher for polyimide optical devices containing polyimide ash at 60°C and 93% relative humidity, and a creep of 40% or less at 60°C.

[0184] Some embodiments of this disclosure provide optical components including polyimide optical devices having at least one surface thereon containing polyimide ash, and an adhesive protective film bonded to the at least one surface.

[0185] Some embodiments of this disclosure provide an optical component comprising a polyimide optical device having at least one surface thereon containing polyimide ash, and an adhesive layer bonded to the at least one surface. The adhesive layer is a photocured product of an adhesive protective film.

[0186] Some embodiments of this disclosure provide cured products including adhesive protective films or optical display devices including optical components.

[0187] Some embodiments of this disclosure provide a method for producing an optical component. The method includes forming a polyimide layer on a substrate; irradiating the surface of the polyimide layer through the substrate to generate polyimide ash on the surface of the polyimide layer; removing the substrate from the polyimide layer; forming an adhesive protective film; and attaching the adhesive protective film to the surface of the polyimide layer.

[0188] The method may also include photocuring of the adhesive protective film.

[0189] In the context of this application, unless otherwise defined, the terms “use,” “being used,” and “being used” may be considered synonymous with the terms “exploit,” “being exploited,” and “being exploited.”

[0190] When describing an embodiment of an inventive concept, the word "may" means "one or more embodiments of the inventive concept".

[0191] Furthermore, any numerical ranges listed herein are intended to include all subranges with the same numerical precision contained within the listed ranges. For example, the range “1.0 to 10.0” is intended to include all subranges between (and including) the listed minimum value of 1.0 and the listed maximum value of 10.0, i.e., a minimum value equal to or greater than 1.0 and a maximum value equal to or less than 10.0, such as (for example) 2.4 to 7.6. Any maximum numerical limit listed herein is intended to include all smaller numerical limits falling within it, and any minimum numerical limit listed in this specification is intended to include all larger numerical limits falling within it. Therefore, the applicant reserves the right to amend this specification, including the claims, to expressly list any subranges falling within the ranges expressly listed herein. It should be understood that various modifications, alterations, changes, and equivalent implementations can be made by those skilled in the art without departing from the spirit and scope of this disclosure.

Claims

1. An adhesive protection film comprising a cured product of a composition, the composition comprising: a (meth)acrylic copolymer; a curing agent; a (meth)acrylic oligomer; and a monofunctional or high-functional (meth)acrylic monomer containing an aromatic group, wherein the adhesive protection film has a storage modulus of 0.1 MPa or less at -20°C, a peel strength of 350 gf / inch or more for a polyimide-based optical device containing polyimide ash at 60°C and 93% relative humidity, and a creep of 40% or less at 60°C, and wherein the adhesive protection film is used for a polyimide-based optical device containing polyimide ash.

2. The adhesive protection film according to claim 1, wherein the (meth)acrylic copolymer has a glass transition temperature (Tg) of -10°C or less.

3. The adhesive protection film according to claim 1, wherein the (meth)acrylic copolymer is a copolymer of a monomer mixture containing a (meth)acrylic monomer having a homopolymer glass transition temperature of 60°C or less and a (meth)acrylic monomer having a crosslinking functional group.

4. The adhesive protection film according to claim 3, wherein the (meth)acrylic monomer having a homopolymer glass transition temperature of 60°C or less and the (meth)acrylic monomer having a crosslinking functional group are present in a total amount of 95 wt% or more, based on 100 wt% of the monomer mixture.

5. The adhesive protection film according to claim 4, wherein the (meth)acrylic monomer having a crosslinking functional group is present in an amount of 0.1 to 20 wt%, based on 100 wt% of the monomer mixture.

7. The adhesive protection film according to claim 1, wherein the (meth)acrylic oligomer has a glass transition temperature of 60°C or less and a weight average molecular weight of 100,000 g / mol or less.

8. The adhesive protection film according to claim 1, wherein the monofunctional or high-functional (meth)acrylic monomer containing an aromatic group has a homopolymer glass transition temperature of -20°C or more.

9. The adhesive protection film according to claim 8, wherein the monofunctional or high-functional (meth)acrylic monomer containing an aromatic group contains at least one of phenoxybenzyl (meth)acrylate or phenoxy polyethylene glycol (meth)acrylate.

10. The adhesive protection film according to claim 1, wherein the composition contains: 100 parts by weight of the (meth)acrylic copolymer; 0.01 to 1 parts by weight of the curing agent; 0.1 to 3 parts by weight of the (meth)acrylic oligomer; and more than 0 to less than or equal to 10 parts by weight of the monofunctional or high-functional (meth)acrylic monomer containing an aromatic group.

11. An optical member comprising: a polyimide-based optical device having at least one surface containing polyimide ash thereon; and an adhesive layer bonded to the at least one surface. ​ 6. The adhesive protection film according to claim 4, wherein the (meth)acrylic monomer having a homopolymer glass transition temperature of 60°C or lower is a mixture comprising a (meth)acrylate having a linear Ci to C 20 alkyl group and a (meth)acrylate having a branched Ci to C 20 alkyl group. ​ ​ ​ ​ ​ ​ ​ ​ wherein the adhesive layer comprises a photocured product of the adhesive protective film according to any one of claims 1 to 10.

12. An optical display device comprising the optical member according to claim 11.

13. A method of producing an optical member, the method comprising: forming a polyimide layer on a substrate; generating polyimide dust by irradiating the polyimide layer through the substrate to form a polyimide dust-containing surface; removing the substrate from the polyimide layer; forming an adhesive protective film; and attaching the adhesive protective film on the polyimide dust-containing surface, wherein the adhesive protective film comprises a cured product of a composition comprising: a (meth)acrylic copolymer; a curing agent; a (meth)acrylic oligomer; and a monofunctional or high-functional (meth)acrylic monomer containing an aromatic group, wherein the adhesive protective film has a storage modulus of 0.1 MPa or less at -20°C, a peeling strength of 350 gf / inch or more for the polyimide dust-containing surface at 60°C and 93% relative humidity, and a creep of 40% or less at 60°C.

14. The method according to claim 13, further comprising photocuring the adhesive protective film to form an adhesive layer.

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