Adhesive protective film, optical member, and optical display device

Abstract

Provided are an adhesive protective film, an optical member, and an optical display device. The adhesive protective film includes a base layer, an adhesive film formed on a first surface of the base layer, and a protective layer formed on a second surface of the base layer, the adhesive film includes a (meth)acrylic copolymer, a curing agent, an aromatic group-containing monofunctional or high-functionality monomer, and an initiator, and the protective layer includes a silicon-based compound and has a pencil hardness value of F to H and a water contact angle value of 90° to 100° at 23°C.

Description

[0001] Citations of relevant applications

[0002] This application claims priority and benefit to Korean Patent Application No. 10-2025-0057452, filed on April 30, 2025, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] One or more aspects of embodiments of the present invention relate to adhesive protective films, optical components, and optical display devices. Background Technology

[0004] In devices such as optical and / or electronic components, protective films, sometimes consisting only of an adhesive layer (e.g., composed of an adhesive layer) or comprising a base film and an adhesive layer, are attached to the surface of the device to prevent or reduce scratches on the device surface during processes such as machining, assembly, and inspection. The protective film is used after the release film of the protective adhesive layer is removed. In recent years, as optical components, there has been a shift from liquid crystal devices to organic light-emitting diode (OLED) devices. Furthermore, the number of OLED devices with flexible properties has been increasing.

[0005] Flexible OLED devices are significantly more flexible than liquid crystal devices and / or conventional OLED devices. Therefore, flexible OLED devices require (or expect) the processing of protective films to prevent or reduce surface scratches and / or protect the OLED panel during processes such as fabrication, assembly, and inspection. When defects such as abnormal appearance or foreign matter are present during panel inspection, appropriately low peel strength and reworking properties are desired or required for easy removal of the protective film. After inspection, a permanently attached patterned film (P-film) is desired or required to support the panel and protect it from moisture and external environmental factors. Because the P-film must be permanently attached to the panel, appropriately high peel strength and reliability are desired or required.

[0006] Therefore, since the process of manufacturing panels requires or is expected to temporarily use a processing protective film with appropriately low peel strength and a P-film with appropriately high peel strength, the process of laminating the processing protective film, the process of peeling the processing protective film, and the process of laminating the P-film are desired or required.

[0007] Those skilled in the art should readily understand the process of using patterned films to manufacture OLED devices with flexible properties. Figure 1 This diagram illustrates part of the process of assembling a panel for an optical display device using an adhesive protective film from a related field.

[0008] refer to Figure 1 A temporary upper protective film 2 and a temporary lower protective film 3 are respectively laminated onto the upper and lower surfaces of the panel 1 (e.g., a polyimide panel) on which OLED light-emitting elements are formed, to manufacture a laminate (I). The laminate is cut with a laser 4 to separate the laminate (II). A portion of the laminate is separated with a laser 5 to obtain a laminate with a small size (the temporary upper protective film 2a and the temporary lower protective film 3a are respectively laminated onto the upper and lower surfaces of the panel 1a on which OLED light-emitting elements are formed) (III). The temporary lower protective film 3a is removed from the laminate, and a portion of the temporary upper protective film 2a is removed (IV). A laminate of a patterned film 8 and a carrier film 6 is laminated onto the lower surface of the panel 1a on which OLED light-emitting elements are formed (V). Then, a display driver 9 can be installed to manufacture a panel with display areas and non-display areas formed thereon (VI).

[0009] The carrier film 6 can be used to protect the patterned film 8. Since the carrier film 6 is used to protect the patterned film, it does not participate in the actual panel manufacturing process. Therefore, the development of a patterned film that does not use the carrier film 6 is underway.

[0010] The background of the present invention is disclosed in Japanese Patent No. 5683369, etc. Summary of the Invention

[0011] One or more aspects of embodiments of this disclosure relate to providing an adhesive protective film that improves the durability and reliability of a polyimide-based optical element having polyimide-based ash, wherein the adhesive protective film adheres to the polyimide optical element, has a significantly higher peel strength after light irradiation than before light irradiation, and is fixed to the optical element.

[0012] One or more aspects of embodiments of this disclosure also relate to providing an adhesive protective film that can be used together (e.g., simultaneously) as a temporary processing protective film in the manufacture of a flexible light-emitting element panel, and as a pattern-enhancing protective film in which only a portion is selectively peeled off to form a pattern.

[0013] Furthermore, one or more aspects of embodiments of this disclosure relate to providing an adhesive protective film that, when used, has excellent or suitable scratch resistance and excellent or suitable panel manufacturing processability.

[0014] According to one or more embodiments of the present disclosure, an adhesive protective film is provided, comprising a substrate layer, an adhesive film formed on a first surface of the substrate layer, and a protective layer formed on a second surface of the substrate layer, wherein the adhesive film comprises a (meth)acrylic copolymer, a curing agent, an aromatic monofunctional or hyperfunctional monomer, and an initiator, and the protective layer comprises a silicon-based compound and has a pencil hardness value of F to H and a water contact angle value of 90° to 100° at 23°C.

[0015] According to one or more embodiments of the present disclosure, an optical component is provided comprising a polyimide optical element having a polyimide gray on at least one surface and an adhesive protective film laminated on one surface having the polyimide gray, wherein the adhesive protective film comprises a base layer, an adhesive film laminated on a first surface of the base layer and a protective layer laminated on a second surface of the base layer, the adhesive film comprising a cured product of a composition comprising a (meth)acrylic copolymer, a curing agent, an aromatic monofunctional or hyperfunctional monomer and an initiator, and the protective layer comprising a silicone compound and having a pencil hardness value of F to H and a water contact angle value of 90° to 100° at 23°C.

[0016] According to one or more embodiments of this disclosure, an optical display device including optical components is provided. Attached Figure Description

[0017] The above and other objectives, features, and advantages of this disclosure will become more apparent to those skilled in the art from the more detailed description of exemplary embodiments thereof with reference to the accompanying drawings, in which:

[0018] Figure 1 This diagram illustrates a part of the process of assembling a panel for an optical display device using an adhesive protective film from the relevant field;

[0019] Figure 2 It is a cross-sectional view of an adhesive protective film according to one or more embodiments;

[0020] Figure 3 It is a cross-sectional view of an adhesive protective film according to one or more other embodiments;

[0021] Figure 4 This is a diagram illustrating a portion of a process for assembling a panel for an optical display device using an adhesive protective film according to one or more embodiments;

[0022] Figure 5One or more embodiments of a method for manufacturing a polyimide-based layer having a polyimide-based gray are shown;

[0023] Figure 6 One or more other embodiments of a method for manufacturing a polyimide layer having a polyimide-like ash are shown; and

[0024] Figure 7 It is a cross-sectional view of one or more embodiments of an optical component. Detailed Implementation

[0025] This disclosure will be described in more detail with reference to exemplary embodiments, so that those skilled in the art can readily practice the invention. This disclosure may be implemented in one or more different suitable forms, and this disclosure is not intended to limit the embodiments described herein.

[0026] The terminology disclosed herein is used solely for the purpose of describing exemplary embodiments, and is not intended to limit this disclosure. Singular expressions include plural expressions unless explicitly stated in the context.

[0027] In this specification, the term "(meth)acrylic acid" may refer to acrylic acid and / or methacrylic acid.

[0028] In this specification, the term "copolymer" may include polymers and / or resins.

[0029] When describing numerical ranges in this specification, the term "X to Y" means X or greater and Y or less (X ≤ and ≤ Y). Furthermore, any numerical ranges listed herein are intended to include all subranges of the same numerical precision falling within the listed range. 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.

[0030] It will be understood that although the terms first, second, etc., may be used herein to describe various elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Therefore, without departing from the teachings of the invention, a first element may be referred to as a second element. Similarly, a second element may be referred to as a first element.

[0031] It will also be understood that, when used in this specification, the terms “includes,” “including,” “comprises,” and / or “comprising” indicate the presence of the stated feature, step, operation, element, and / or component, but do not exclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. Furthermore, the terms “comprise(s)” / “comprising,” “include(s)” / “including,” “have” / “has” / “having” or similar terms include or support the terms “consisting of” and “substantially composed of”, indicating the presence of the stated feature, integer, step, operation, element, and / or component, while other features, integers, steps, operations, elements, components, and / or groups thereof are absent or substantially absent.

[0032] As used herein, the terms “use,” “using,” and “used” can be considered synonymous with the terms “utilize,” “utilizing,” and “utilized,” respectively.

[0033] As used herein, when preceding a list of elements, expressions such as “at least one of…”, “one of…”, and “selected from…” modify the entire list of elements but not individual elements of the list. For example, “selected from at least one of a, b, and c”, “at least one of a, b, or c”, and “at least one of a, b, and / or c” can indicate only a, only b, only c, both a and b (e.g., simultaneously), both a and c (e.g., simultaneously), both b and c (e.g., simultaneously), all of a, b, and c, or variations thereof.

[0034] As used herein, the term “and / or” includes any and all combinations of one or more of the relevant listed items.

[0035] Furthermore, when describing embodiments of this disclosure, the word "may" is used to mean "one or more embodiments of this disclosure".

[0036] It will be understood that when a component is referred to as being "on," "connected to," or "coupled to" another component, it can be directly on, connected to, or coupled to the other component, or there may be one or more intermediate components. When a component is referred to as being "directly on," "directly connected to," or "directly coupled to" another component, there are no intermediate components.

[0037] For ease of description, spatial relative terms such as “below,” “under,” “lower,” “above,” “upper,” “bottom,” “top,” etc., may be used herein to describe the relationship of one element or feature relative to another element or feature as shown in the figures. It will be understood that spatial relative terms are intended to cover different orientations of the device in use or operation, other than those depicted in the figures. For example, if the device in the figures is flipped, an element described as “below” or “under” other elements or features is oriented as “above” or “on” other elements or features. Thus, the term “below” can encompass both upper and lower orientations. The device may be otherwise oriented (rotated 90 degrees or in other orientations), and the spatial relative descriptors used herein should be interpreted accordingly.

[0038] Electronic devices and / or any other related devices or components according to embodiments of the present disclosure described herein can be implemented using any suitable hardware, firmware (e.g., application-specific integrated circuits), software, or a combination of software, firmware, and hardware. For example, various components of the device can be formed on an integrated circuit (IC) chip or a discrete IC chip. Furthermore, various components of the device can be implemented on a flexible printed circuit film, tape-on-a-carrier package (TCP), printed circuit board (PCB), or formed on a substrate. Additionally, various components of the device can be processes or threads that run on one or more processors in one or more computing devices, execute computer program instructions, and interact with other system components to perform the various functions described herein. The computer program instructions are stored in memory, which can be implemented in a computing device using standard storage devices such as, for example, random access memory (RAM). The computer program instructions can also be stored in other persistent computer-readable media, such as, for example, CD-ROMs, flash drives, etc. Furthermore, those skilled in the art will recognize that the functionality of various computing devices can be combined or integrated into a single computing device, or the functionality of a particular computing device can be distributed among one or more other computing devices, without departing from the scope of embodiments of the present disclosure.

[0039] In light of the overall content of this disclosure, those skilled in the art will understand that each suitable feature of the various embodiments of this disclosure may be combined in part or in whole, or combined with one another, and may be technically interlocked and operated in various suitable ways, and each embodiment may be implemented independently of one another or in combination with one another in any suitable way, unless otherwise stated or implied.

[0040] An adhesive protective film according to one or more exemplary embodiments includes a base layer, an adhesive film provided (e.g., laminated) on a first surface of the base layer, and a protective layer provided (e.g., laminated) on a second surface of the base layer.

[0041] The first and second surfaces can be opposite each other.

[0042] The adhesive film can be in a state before light radiation, and can be a thermosetting product of a composition for adhesive films, as described in more detail.

[0043] Before light radiation, the adhesive film can adhere to a surface with polyimide ash to temporarily protect it. For example, the adhesive film can prevent or reduce scratches on the surface with polyimide ash during processes such as processing, assembly, and inspection. In some embodiments, the adhesive film can adhere to the surface with polyimide ash without (or substantially without) generating bubbles.

[0044] The adhesive film can be an adhesive film whose peel strength can vary due to light radiation. After light radiation, the adhesive film adheres to the surface with polyimide ash with a higher peel strength than before light radiation, thereby enhancing the durability and reliability of polyimide optical components.

[0045] "Polyimide optical elements" can be polymer films processed through a polymerization reaction from polyamic acid, which is a precursor and contains imide and aromatic groups in repeating units. Polyimide optical elements have excellent or suitable mechanical and thermal properties, and therefore can be used as substrates for flexible OLED panels.

[0046] In one or more embodiments, the polyimide optical element may be in the form of a polyimide layer. A method for manufacturing a polyimide layer having a surface containing polyimide ash is described in more detail below.

[0047] During the process of assembling a panel using an adhesive protective film laminated onto the second surface of a substrate, the protective layer can be continuously (e.g., substantially continuously) exposed. In this case, scratches, marks, etc., can occur on the protective layer during transfer due to contact with external foreign objects. This can interfere with the continuity of the panel assembly process. Furthermore, if the adhesive protective film is permanently laminated onto the panel by means of light radiation (e.g., by curing the adhesive protective film), the panel quality can be degraded.

[0048] In the following text, one or more embodiments of the adhesive protective film will be described.

[0049] protective layer

[0050] The protective layer can be laminated onto the second surface of the base layer to protect the adhesive protective film from external objects, impacts, and / or contact.

[0051] A protective layer can be formed directly on the second surface of the substrate. In this document, "directly formed" refers to an embodiment in which no adhesive layer or pressure-sensitive adhesive layer is formed between the second surface of the substrate and the protective layer.

[0052] In one or more embodiments, the protective layer may be a coating formed on the second surface of the base layer.

[0053] For example, the protective layer can be formed by a curing process after the second surface of the substrate is coated with the composition for the protective layer. Curing can be, for example, UV curing and / or thermal curing. The composition for the protective layer may contain an adhesive and a silicone-based compound.

[0054] Silicon-based compounds are compounds containing silicon (Si) in their structure and can be in the form of compounds having a siloxane (Si-O-Si) structure (where silicon (Si) and oxygen (O) are bonded as the basic skeletal structure) and having one or more suitable organic groups bonded thereto. For example, silicon-based compounds can be in the form of polydimethylsiloxane (PDMS), silane coupling agents, and / or silicone resins, but these are merely examples and implementation is not limited thereto. Silicon-based compounds can contain one or more suitable functional groups in their structure. From the perspective of enhancing scratch resistance, for example, silicon-based compounds can contain polyfunctional acrylic groups in their structure.

[0055] By incorporating silicon-based compounds, the protective layer can improve scratch resistance while maintaining a certain level of adhesive strength, and can also help ensure stability during the panel manufacturing process and the reliability of the final product. In one or more embodiments, by incorporating silicon-based compounds, the protective layer can improve the appearance quality and optical uniformity of the protective layer.

[0056] For example, a silicon-based compound may be included in the composition for the protective layer in an amount of 0.1% to 0.4% by weight, and may be included within the aforementioned ranges, for example, 0.1% to 0.3% by weight, 0.1% to 0.25% by weight, 0.1% to 0.24% by weight, or 0.12% to 0.24% by weight. In this case, the protective layer can ensure an appropriate level of mechanical strength sufficient to adequately or appropriately protect the outer surface of the adhesive protective film. Therefore, even without adding a separate carrier film to the outermost layer, the adhesive protective film according to one or more embodiments of the present disclosure can ensure or improve process stability by preventing or reducing scratches on the outer surface of the film.

[0057] However, if (for example, when) it has a carrier film attached to its outermost layer, the adhesive protective film according to this disclosure may also be used. The adhesive protective film according to one or more other embodiments of this disclosure further includes a carrier film formed on the protective layer. In this case, if (for example, when) necessary or desired, the peel strength between the added carrier film and the protective layer can meet a set or predetermined level, thereby allowing the carrier film to detach. From this perspective, the peel strength of the carrier film according to one or more embodiments may be 7 to 15 gf / inch, and may be 8 to 14 gf / inch or 9 to 13 gf / inch within the aforementioned range.

[0058] Any suitable adhesive may be used as an adhesive included in the composition for the protective layer, provided that it does not adversely affect the haze and total light transmittance of the adhesive protective film. For example, the adhesive may include at least one selected from urethane-based resins and urethane (meth)acrylate resins, but this disclosure is not limited thereto.

[0059] The composition used for the protective layer may also include a diluent and an initiator. For example, a diluent such as triethylene glycol dimethacrylate can be used as a diluent. The initiator may be a photoinitiator and may be an initiator including azo polymerization initiators and / or peroxides such as benzoyl peroxide and / or acetyl peroxide.

[0060] The composition for the protective layer may also contain a solvent. The solvent can enhance the coating properties of the composition to provide a protective layer with a suitably thin thickness and a substantially uniform surface. The solvent may include one or more types (classes) of solvents suitable in the art. For example, the solvent may include methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, toluene, etc., but this disclosure is not limited thereto. In one or more embodiments, the composition may contain an adhesive protective film with a solid content (e.g., amount) of 15% to 40% by weight, for example 20% to 30% by weight. Within the above range, the composition may have excellent or suitable coating properties.

[0061] The protective layer has a pencil hardness value of F to H and a water contact angle value of 90° to 100° at 23°C. Therefore, the protective layer can provide an adhesive protective film with excellent or suitable scratch resistance, which can improve the processability of panel manufacturing using adhesive protective films and improve panel quality.

[0062] In this specification, pencil hardness can be defined as the grade of the hardest pencil that, if (e.g., when) scratches a sheet surface with a pencil lead under constant load, leaves no mark on the sheet surface, including an adhesive protective film. For example, pencil hardness can be a measure of the scratch resistance of a sheet surface including an adhesive protective film. For example, pencil hardness can be expressed as grades such as H (hard), F (hard and sharp), B (black), etc. For example, pencil hardness H can be harder than pencil hardness F and pencil hardness B, and pencil hardness F can be harder than pencil hardness B.

[0063] When the pencil hardness value of the protective layer does not meet the above range, scratches can occur on the surface of the protective layer during module processing. Therefore, since the carrier film must be present on the protective layer in this case, there may be limitations in terms of process efficiency.

[0064] When the water contact angle of the protective layer is less than 90°, insufficient slipperiness may lead to scratches due to external impacts and / or contact. When the water contact angle of the protective layer is greater than 100°, excessive use of leveling agent may result in unreacted leveling agent sedimentation under durability reliability conditions (60°C × 95% × 500 hours).

[0065] As described in more detail below, a protective layer can be formed facing the adhesive film. If (for example, when) the protective layer has a pencil hardness value of F to H and a water contact angle value of 90° to 100° at 23°C, the protective layer can ensure or improve the scratch resistance of the adhesive protective film both before and after light radiation (for example, simultaneously).

[0066] In one or more embodiments, the thickness of the base layer, as described below, can be considered to determine or select the thickness of the protective layer. For example, the thickness ratio of the base layer to the protective layer can be from 10:1 to 200:1. When the thickness ratio of the base layer to the protective layer is set or selected to a set or predetermined range, scratches can be prevented or reduced during module manufacturing, and the protective layer can be prevented or reduced during stamping. In some embodiments, the thickness ratio of the base layer to the protective layer can be from 10:1 to 150:1, 10:1 to 140:1, or 10:1 to 130:1, but these are merely examples and the implementation is not limited thereto. From this perspective, the thickness of the protective layer can be, for example, 0.5 micrometers or more and less than 5.0 micrometers, 0.6 micrometers or more and less than 5.0 micrometers, 0.7 micrometers or more and less than 5.0 micrometers, 0.7 micrometers or more and less than 4.0 micrometers, or 0.7 micrometers or more and less than 3.0 micrometers. When the thickness of the protective layer is outside the above ranges (e.g., greater than the above ranges), the adhesive protective film may break if (e.g., when) stamping is performed. If (for example, when) the thickness of the protective layer is less than the range mentioned above, the pencil hardness of the protective layer may be reduced, which may degrade the manufacturability of the module.

[0067] Adhesive film

[0068] The adhesive film comprises (meth)acrylic copolymers, curing agents, monofunctional or highly functional monomers containing aromatic groups (e.g., monomers having one or more functional groups) and initiators.

[0069] When the initial peel strength of the adhesive film relative to the surface with polyimide ash is A, and after laminating the adhesive film onto the surface with polyimide ash and irradiating it with light, the peel strength of the adhesive film relative to the surface with polyimide ash is B, then the following expression 1 can be satisfied:

[0070] Expression 1

[0071] A

[0072] According to some embodiments, an adhesive film is adhered to a polyimide optical element having a polyimide-based ash, and the peel strength after light radiation is significantly improved compared to before light radiation. Therefore, the adhesive protective film with the adhesive film can be used not only as a temporary processing protective film in the flexible light-emitting element panel substrate, but also as a pattern-enhancing protective film after pattern formation.

[0073] ​In one or more embodiments, the adhesive film may have an initial peel strength of 7 gf / inch or less relative to the surface having a polyimide-based ash. Within this range, the adhesive film can be adhered to a flexible light-emitting element panel substrate to protect the panel substrate and can also be used as a temporary processing protective film because the adhesive film can be easily removed in case of problems. For example, the initial peel strength may be greater than 0 gf / inch and less than or equal to 7 gf / inch, such as 1 to 7 gf / inch or 4 to 7 gf / inch. In this document, "initial peel strength" refers to the peel strength before the protective film is bonded with light radiation.

[0074] In one or more embodiments, an adhesive film can be laminated onto a surface having a polyimide-based ash and can have a peel strength of 200 gf / inch or greater relative to the surface having the polyimide-based ash after light irradiation. Within the aforementioned range, the adhesive film can be permanently laminated onto polyimide optical elements having a polyimide-based ash, thereby enhancing durability and reliability. For example, after light irradiation, the adhesive film can have a peel strength of 300 gf / inch or greater, such as 300 to 600 gf / inch.

[0075] In this document, "optical radiation" may include wavelengths of 280 nm to 430 nm, such as 360 nm to 390 nm, at a concentration of 1,000 mJ / cm². 2 Radiant energy. UV radiation is applied using one or more of the following: UV LEDs, high-pressure mercury lamps, and metal halide lamps.

[0076] In this paper, the "peel strength" of a surface with polyimide-based grease can be measured using a tensile testing instrument, Texture Analyzer (TAIndustry), at a peel temperature of 25°C, a peel speed of 2,400 mm / min, and a peel angle of 180°, according to JIS Z2037.

[0077] In one or more embodiments, the adhesive film is a peel strength-enhanced adhesive film that exhibits significantly increased peel strength after light radiation compared to before radiation. Because the adhesive film has increased peel strength after light radiation, it is adhered to polyimide optical elements after light radiation to provide permanent protection. Therefore, the adhesive protective film, which together (e.g., simultaneously) has the adhesive film, provides both temporary and permanent protection to the polyimide optical elements, and can thus (e.g., simultaneously) serve as both a temporary processing protective film and a reinforcing protective film, thereby achieving simplified processes, economic efficiency, and environmental friendliness. The temporary processing protective film can be a film temporarily adhered to the substrate and then removed, and can be a film that temporarily protects the polyimide optical elements. The reinforcing protective film can be a film permanently adhered to the polyimide optical elements to protect them from external environmental influences and cannot be removed from the polyimide optical elements.

[0078] Adhesive protective films can be used as reinforcing protective films. Reinforcing protective films refer to protective films laminated on at least one side of a flexible panel to protect the flexible panel from external impacts and other effects.

[0079] In one or more embodiments, the adhesive film may have a peel strength improvement rate of 50 or greater, which is the ratio of B to A as defined in Expression 1 above. Within this range, the adhesive film can adhere to polyimide optical elements and then adhere to the polyimide optical elements with appropriately high peel strength and appropriately high reliability after light radiation, thereby achieving adhesive properties on the polyimide optical elements.

[0080] The adhesive film may comprise a cured product of a composition for use in the adhesive film, said composition comprising a (meth)acrylic copolymer, a curing agent, an aromatic monofunctional or hyperfunctional monomer, and an initiator. In one or more embodiments, the cured product may be a thermosetting product.

[0081] In one or more embodiments, the adhesive film may have an aromatic monofunctional or hyperfunctional monomer and an initiator dispersed in an adhesive protective film matrix formed by thermosetting of (meth)acrylic copolymers and isocyanate curing agents.

[0082] (meth)acrylic acid copolymers

[0083] By curing with isocyanate-based curing agents, (meth)acrylic copolymers can form the matrix of adhesive films and provide initial peel strength. After light irradiation, (meth)acrylic copolymers can also help improve the modulus and cohesiveness of adhesive films together with aromatic monofunctional or hyperfunctional monomers.

[0084] (Meth)acrylic acid copolymers can have a glass transition temperature (Tg) of -10°C or lower, for example, -60°C to -20°C. If the glass transition temperature of the (meth)acrylic acid copolymer is within this range, it can help provide wettability (adhesion) and initial peel strength of the adhesive film to polyimide optical components. After light irradiation, peel strength can be improved by controlling the glass transition temperature to suppress or reduce shrinkage of the adhesive film compared to oligomers formed from monofunctional or hyperfunctional monomers.

[0085] (Meth)acrylic copolymers can have a weight-average molecular weight of 500,000 g / mol or greater, for example, 600,000 to 1,500,000 g / mol. If the weight-average molecular weight of the (meth)acrylic copolymer is within the above range, the (meth)acrylic copolymer can help provide wettability (adhesion) to the adherend and initial peel strength of the adhesive film.

[0086] In this paper, differential scanning calorimetry (DSC) can be used to measure the glass transition temperature by any suitable method, and the weight-average molecular weight can be calculated as the polystyrene transition value by gel permeation chromatography.

[0087] (Meth)acrylic copolymers may include copolymers of monomer mixtures, which include alkyl-containing (meth)acrylic monomers and hydroxyl-containing (meth)acrylic monomers.

[0088] Alkyl-containing (meth)acrylate monomers form the matrix of the adhesive protective film and may include unsubstituted alkyl-containing (meth)acrylates having 1 to 20 carbon atoms, for example 2 to 11 carbon atoms.

[0089] For example, alkyl-containing (meth)acrylate monomers may include one or more selected from the following: methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, tert-butyl methacrylate, isobutyl methacrylate, pentyl methacrylate, hexyl methacrylate, heptyl methacrylate, ethylhexyl methacrylate, octyl methacrylate, isooctyl methacrylate, nonyl methacrylate, decyl methacrylate, and lauryl methacrylate.

[0090] Alkyl-containing (meth)acrylic monomers may be included in the monomer mixture in amounts of 85 mol% to 99.5 mol%, for example, 90 mol% to 98 mol% or 95 mol% to 99 mol%. Within any of the above ranges, suitable wetting of the adherend and initial peel strength of the adhesive film can be achieved.

[0091] Hydroxyl-containing (meth)acrylate monomers can be (meth)acrylates containing one or more hydroxyl groups. For example, hydroxyl-containing (meth)acrylates may include one or more 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.

[0092] Hydroxyl-containing (meth)acrylic monomers may be included in the monomer mixture in amounts from 0.1 mol% to 10 mol%, for example, 0.5 mol% to 10 mol%, 0.5 mol% to 5 mol%, 2 mol% to 10 mol%, or 1 mol% to 5 mol%. Within any of the above ranges, hydroxyl-containing (meth)acrylic monomers can effectively or appropriately provide cohesion for the adhesive film to form an adhesive film and provide the initial peel strength of the adhesive film.

[0093] The monomer mixture may contain (meth)acrylic monomers with a homopolymer glass transition temperature of -80°C or higher and 0°C or lower, for example -60°C to -20°C. If the glass transition temperature is within the above range, (meth)acrylic copolymers having the above glass transition temperature range can be readily or can be manufactured.

[0094] In one or more embodiments, the monomer mixture may contain (meth)acrylate monomers with a homopolymer glass transition temperature of -80°C or higher and 0°C or lower, for example -60°C to -20°C, in an amount of 90 mol% or more, such as 95 mol% or more, or 95 to 99 mol% of the monomer mixture. Within this range, the effects of the present disclosure described above can be readily or suitably achieved. Such (meth)acrylate monomers may be n-butyl acrylate, etc.

[0095] In one or more embodiments, the monomer mixture may not contain (e.g., may exclude) monomers having aromatic groups. Adhesive protective films made from (meth)acrylic copolymers formed from monomers having aromatic groups may not achieve the aforementioned peel strength improvement rate.

[0096] In one or more embodiments, the total (e.g., combination) of alkyl-containing (meth)acrylic acid monomers and hydroxyl-containing (meth)acrylic acid monomers contained in the monomer mixture may be 99 mol% or more, for example 99 to 100 mol% or 100 mol%.

[0097] (Meth)acrylic acid copolymers can be produced by polymerizing a monomer mixture using any suitable polymerization method. The polymerization method can include methods suitable in the art. For example, (meth)acrylic acid copolymers can be produced by adding an initiator to a monomer mixture and then subjecting the resulting mixture to copolymerization methods such as suspension polymerization, emulsion polymerization, solution polymerization, etc. The polymerization temperature can be from 60°C to 70°C, and the polymerization time can be from 4 hours to 8 hours. Initiators, including azo polymerization initiators and / or peroxides such as benzoyl peroxide and / or acetyl peroxide, can be used as initiators.

[0098] curing agent

[0099] Curing agents can help thermocure (meth)acrylic copolymers to form the matrix of the adhesive film and provide the initial peel strength of the adhesive film.

[0100] The curing agent may include isocyanate curing agents as thermosetting agents, and based on 100 parts by weight of the (meth)acrylic copolymer, it may include isocyanate curing agents in amounts of 0.1 to 20 parts by weight. For example, based on 100 parts by weight of the (meth)acrylic copolymer, it may include isocyanate curing agents in amounts of 6 to 20 parts by weight, 7 to 20 parts by weight, 7 to 10 parts by weight, 8 to 15 parts by weight, or 8 to 10 parts by weight.

[0101] Isocyanate curing agents may include difunctional or higher-functional isocyanate curing agents (e.g., isocyanate curing agents having two or more functional groups), such as difunctional to hexafunctional isocyanate curing agents. In one or more embodiments, the isocyanate curing agent may include one or more selected from: xylene diisocyanate (XDI), including m-xylene diisocyanate, etc.; methylene bis(phenyl isocyanate) (MDI), including 4,4'-methylene bis(phenyl isocyanate), etc.; naphthalene diisocyanate; toluene diisocyanate; hexamethylene diisocyanate; isophorone diisocyanate and / or adducts thereof. For example, the adduct may be a trimethylolpropane adduct of toluene diisocyanate, a trimethylolpropane adduct of hexamethylene diisocyanate, a trimethylolpropane adduct of isophorone diisocyanate, a trimethylolpropane adduct of xylene diisocyanate, an isocyanurate adduct of toluene diisocyanate, an isocyanurate adduct of hexamethylene diisocyanate, and / or an isocyanurate adduct of isophorone diisocyanate. One or more isocyanate curing agents may be included in at least one of the compositions.

[0102] Curing agents may also include metal chelate curing agents.

[0103] In one or more embodiments, isocyanate curing agents and metal chelate curing agents may be included in a weight ratio of 5:1 to 10:1, for example, 6:1 to 10:1. If the ratio is within the above range, the effect of the adhesive film can be easily or appropriately achieved.

[0104] Suitable metal chelate curing agents can be used as metal chelate curing agents. In this case, metal chelate curing agents can include curing agents containing metals such as aluminum, iron, copper, zinc, tin, titanium, nickel, antimony, magnesium, vanadium, chromium, zirconium, etc. For example, metal chelate curing agents may include one or more selected from the following: aluminum ethyl acetoacetate diisopropylate, aluminum tris(ethyl acetoacetate), alkyl acetoacetate diisopropylate, aluminum isopropylate, mono-sec-butoxy aluminum diisopropylate, aluminum-sec-butyrate, aluminum ethylate, tetraisopropyl titanate, tetra-n-butyl titanate, butyl titanate dimer, titanium acetylacetone, titanium octylene glycolate, titanium tetraacetylacetone, and titanium ethyl acetylacetone. Ethylacetoacetate, polyhydroxy titanium stearate, and aluminum acetylacetonate.

[0105] Based on 100 parts by weight of the (meth)acrylic copolymer, a metal chelate curing agent may be included in an amount of 3 parts by weight or less, for example, 0.001 parts by weight to 1 part by weight, and in some embodiments, 0.01 parts by weight to 1 part by weight. Within any of the foregoing ranges, additional beneficial effects can be achieved without significantly reducing the effectiveness of the adhesive film of this disclosure.

[0106] Based on 100 parts by weight of the (meth)acrylic copolymer, a curing agent, such as a mixture of isocyanate curing agents and metal chelate curing agents, may be included in amounts of 8 to 20 parts by weight, for example 8.5 to 15 parts by weight, and in some embodiments 8.5 to 10.5 parts by weight or 8.5 to 10 parts by weight. Within any of the above ranges, the reliability of the adhesive film can be enhanced.

[0107] Monofunctional or highly functional monomers containing aromatic groups

[0108] Monofunctional or highly functional monomers containing aromatic groups (e.g., monomers having one or more functional groups) have an aromatic group and one or more functional groups capable of reacting with an initiator. The term "aromatic" can refer to a monocyclic or heterocyclic functional group having 6 to 50 carbon atoms. For example, the term "aromatic" can refer to substituted or unsubstituted benzyl, phenyl, biphenyl, terphenyl, naphthyl, etc. Furthermore, the term "functional group" can refer to a vinyl group and / or a (meth)acrylate group, which, if (e.g., when) cured by light radiation, can be effective or suitable for preventing or reducing excessive shrinkage of the adhesive film.

[0109] Monofunctional or hyperfunctional monomers containing aromatic groups contain aromatic groups and can therefore enhance the attractiveness between the adhesive film and the substrate (e.g., plastic films with aromatic groups such as polyimide films) through π-π bonding stacking, thereby contributing to improved adhesive film adhesion strength to the substrate. Furthermore, if (e.g., when) the aromatic group is a relatively large substituent compared to straight-chain or branched alkyl groups, and if (e.g., when) the aromatic group is inserted between the network type or type of cured product (e.g., interpenetrating polymer network (IPN) structure and / or semi-IPN structure) of the (meth)acrylic copolymer and the curing agent before light irradiation, it can help suppress or reduce excessive increase in the initial peel strength of the adhesive film to the substrate.

[0110] Following light radiation, monofunctional or hyperfunctional monomers containing aromatic groups can increase the cohesiveness and / or modulus of the adhesive film. Therefore, if the adhesive film is light-cured while it is being adhered to the surface of the substrate, the peel strength of the adhesive film can be improved by allowing it to adhere to the substrate with a higher peel strength.

[0111] According to one or more embodiments, the glass transition temperature of the homopolymer of the aromatic monofunctional or polyfunctional monomer has a set or predetermined range compared to the glass transition temperature of the (meth)acrylic acid copolymer. Therefore, even when the adhesive film is cured by light radiation, shrinkage of the adhesive film can be suppressed or reduced, thereby improving the peel strength after light radiation. The glass transition temperature of the homopolymer of the aromatic monofunctional or polyfunctional monomer is higher than that of the (meth)acrylic acid copolymer, and the difference between them can be 20°C or greater, for example, 20°C to 120°C or 40°C to 100°C. Within any of the above ranges, an increase in peel strength after light radiation can be expected.

[0112] Aromatic monofunctional or hyperfunctional monomers can have homopolymer glass transition temperatures of 6°C or higher, for example, 6°C to 50°C. If the homopolymer glass transition temperature is within the above range, since the glass transition temperature is higher than that of (meth)acrylic copolymers, the property of improving the peel strength of the adhesive film can be achieved by improving cohesion after light irradiation.

[0113] Monofunctional or highly functional monomers containing aromatic groups may include compounds of Formula 1, but this disclosure is not limited thereto:

[0114] Chemical Formula 1

[0115] ,

[0116] in:

[0117] R 1 It is either hydrogen or methyl, s is an integer from 0 to 10, R 2 It is a substituted or unsubstituted aryl group having 6 to 50 carbon atoms or a substituted or unsubstituted aryloxy group having 6 to 50 carbon atoms, and T is a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms or a substituted or unsubstituted alkylene group having 1 to 6 carbon atoms.

[0118] In this specification, the term "substituted or unsubstituted" means a functional group in which one or more hydrogen atoms are substituted by an alkyl group having 1 to 10 carbon atoms, a thioalkyl group having 1 to 10 carbon atoms, an alkoxy group having 1 to 10 carbon atoms, a halogen (F, Cl, Br and / or I), a cycloalkyl group having 3 to 10 carbon atoms, and / or an aryl group having 6 to 20 carbon atoms.

[0119] For example, R 2It can be substituted or unsubstituted phenoxy, benzyl, phenyl, biphenyl, terphenyl, naphthyl, etc. For example, monofunctional or highly functional monomers containing aromatic groups can include one or more selected from the following: phenoxy(meth)acrylate, 2-ethylphenoxy(meth)acrylate, benzyl (meth)acrylate, phenyl (meth)acrylate, 2-ethylthiophenyl (meth)acrylate. (meth)acrylate), 2-phenylethyl (meth)acrylate, 3-phenylpropyl (meth)acrylate, 4-phenylbutyl (meth)acrylate, 2-(2-methylphenyl)ethyl (meth)acrylate, 2-(3-methylphenyl)ethyl (meth)acrylate, 2-(4-methylphenyl)ethyl (meth)acrylate, 2-(4-propylphenyl)ethyl (meth)acrylate, 2-(4-(1-methylethyl)phenyl)ethyl (meth)acrylate, 2-(4-methoxyphenyl)ethyl (meth)acrylate, 2-(4-cyclohexylphenyl)ethyl (meth)acrylate, 2-(2-chlorophenyl)ethyl (meth)acrylate, 2-(3-chlorophenyl)ethyl (meth)acrylate, 2-(4-chlorophenyl)ethyl (meth)acrylate, 2-(4-bromophenyl)ethyl (meth)acrylate, 2-( 3-Phenylacetyl ethyl acrylate, o-phenyl acrylate, m-phenyl acrylate, p-phenyl acrylate, 2,6-triphenyl acrylate, o-triphenyl acrylate, m-triphenyl acrylate, p-triphenyl acrylate, 4-(4-methylphenyl)phenyl acrylate, 4-(2-methylphenyl)phenyl acrylate, 2-(4-methylphenyl)phenyl acrylate, 2-(2-methylphenyl)phenyl acrylate, 4-(4-ethylphenyl)phenyl acrylate, 4-(2-ethylphenyl)phenyl acrylate, 2-(4-ethylphenyl)phenyl acrylate, and 2-(2-ethylphenyl)phenyl acrylate may be included individually or in combination of two or more.

[0120] In one or more embodiments, the aromatic-group-containing monofunctional or highly functional monomer may include at least one selected from the following: benzyl (meth)acrylate, ethoxylated phenyl acrylate (phenyl(EO)1 acrylate, phenyl(EO)2 acrylate), ethoxylated phenylphenol acrylate (o-phenylphenol(EO) acrylate), phenoxybenzyl (meth)acrylate, biphenyl methyl acrylate, and naphthyl acrylate, including 1-naphthyl acrylate, etc.

[0121] In one or more embodiments, phenoxybenzyl (meth)acrylate may be used.

[0122] Based on 100 parts by weight of the (meth)acrylic copolymer, an aromatic monofunctional or hyperfunctional monomer may be included in an amount of 120 parts by weight or more, for example, 120 to 150 parts by weight or 120 to 130 parts by weight. Within any of the foregoing ranges, the aromatic monofunctional or hyperfunctional monomer may contribute to improving the peel strength of the adhesive film after light irradiation and may inhibit or reduce the shrinkage of the adhesive film.

[0123] Initiator

[0124] Initiators can provide physical changes to adhesive films during light radiation by curing monofunctional or hyperfunctional monomers containing aromatic groups. Initiators may include one or more selected from photoradical initiators and cationic photoinitiators, and may also include thermal initiators.

[0125] In one or more embodiments, the initiator may include a photoinitiator having a maximum absorption wavelength within the wavelength range of radiation applied during the aforementioned light radiation. For example, the initiator may have a maximum absorption wavelength in the range of 280 nm to 430 nm. If the initiator has a maximum absorption wavelength within the aforementioned range, photocuring properties of monofunctional or hyperfunctional monomers containing aromatic groups can be achieved during light radiation. For example, the initiator may include phosphorus-based initiators, ketone-based initiators, etc., but this disclosure is not limited thereto.

[0126] Based on 100 parts by weight of (meth)acrylic copolymer, an initiator may be included in an amount from 0.01 parts by weight to 7.5 parts by weight, for example from 0.03 parts by weight to 4.5 parts by weight. When the amount of initiator is within any of the above ranges, substantially uniform curing of the aromatic monofunctional or hyperfunctional monomer can be achieved during light radiation, and a decrease in the transparency of the adhesive film due to residual initiator can be prevented or reduced.

[0127] Compositions for use in adhesive films may also contain curing accelerators.

[0128] Curing accelerators can aid the curing reaction of adhesive films, thereby further enhancing the cohesiveness of the adhesive film. Curing accelerators may include suitable curing accelerators in the art. Examples include tin-based metal compounds, zinc-based metal compounds, amine-based compounds, titanium-based metal compounds, bismuth-based metal compounds, and / or aluminum-based metal compounds. Tin-based metal compounds may be used. Examples include tetravalent or divalent organotin compounds, such as dibutyltin dilaurate, bis-acetylacetonate-dibutyltin, dibutyltin dimaleate, tin dimaleate, etc., but this disclosure is not limited thereto.

[0129] Based on 100 parts by weight of (meth)acrylic copolymer, a curing accelerator may be included in an amount from 0.001 parts by weight to 3 parts by weight. If the amount of curing accelerator is within the above range, the curing accelerator can help increase the curing speed of the adhesive film and improve the cohesiveness of the adhesive film.

[0130] Compositions for use in adhesive films may also contain silane coupling agents.

[0131] Silane coupling agents can further improve the peel strength of the adhesive protective film. Silane coupling agents can include one or more suitable silane coupling agents in the art. For example, silane coupling agents can include epoxy-containing silane coupling agents, such as glycidoxypropyltrimethoxysilane, glycidoxypropylmethyldimethoxysilane, etc., but this disclosure is not limited thereto.

[0132] Based on 100 parts by weight of (meth)acrylic copolymer, a silane coupling agent may be included in an amount from 0.01 parts by weight to 5 parts by weight. If the amount of silane coupling agent is within the above range, the peel strength can be further enhanced and the properties improved.

[0133] The composition for use in adhesive films may also contain additives. Additives may include one or more suitable additives that can be included in the adhesive film. For example, additives may include one or more selected from: pigments, ultraviolet absorbers, antioxidants, leveling agents, antistatic agents, retarding agents, catalysts, and reworking agents, but this disclosure is not limited thereto.

[0134] The composition for use as an adhesive film may also contain a solvent. The solvent can improve the coating properties of the composition to provide an adhesive protective film with a suitably thin thickness and a substantially uniform surface. The solvent may include one or more suitable solvents of one or more types (classes) in the art. For example, the solvent may include methyl ethyl ketone, methyl isobutyl ketone, ethyl acetate, toluene, etc., but this disclosure is not limited thereto. In one or more embodiments, the composition may contain an adhesive protective film with a solid content (e.g., amount) of 15% to 40% by weight, specifically 20% to 30% by weight. If the solid content of the adhesive protective film is within the above range, the composition may have excellent or suitable coating properties.

[0135] The adhesive film can have a thickness of 200 μm or less, for example, greater than 0 μm and less than 100 μm, and in some embodiments, a thickness of 5 μm to 50 μm. If the thickness of the adhesive film is within the above range, the adhesive film can help provide protective properties for the flexible panel.

[0136] basal layer

[0137] The base layer supports the adhesive protective film.

[0138] The substrate layer may be a film comprising an optically transparent resin. In one or more embodiments, the resin may include a film, said film comprising: polyester films, including polyethylene terephthalate films, polyethylene naphthalate films, etc.; polycarbonate films; polyethersulfone films, etc.

[0139] The substrate layer can have a thickness of 200 μm or less, for example, greater than 0 μm and less than 100 μm, and in some embodiments, a thickness of 5 μm to 75 μm or 5 μm to 50 μm. If the thickness of the substrate layer is within the above range, the substrate layer can help provide protective properties for the flexible panel.

[0140] In the visible light region (e.g., wavelengths from 380 nm to 780 nm), the adhesive protective film may have a haze of 5% or less, for example, 0.1% to 2%, and a total light transmittance of 80% or more, for example, 85% to 95%. If the haze and total light transmittance are within their respective ranges described above, the adhesive protective film can be used in optical display devices due to its good or suitable optical transparency.

[0141] Adhesive protective films can also include release films formed on one surface of the adhesive film. Release films can be used to protect adhesive films from external contaminants. Any suitable type (variety) of material can be used as a release film.

[0142] Figure 2 It is a cross-sectional view of an adhesive protective film according to one or more embodiments.

[0143] refer to Figure 2 The adhesive protective film may include a base layer 10, an adhesive film 20 laminated on a first surface of the base layer 10, and a protective layer 30 laminated on a second surface of the base layer 10.

[0144] Figure 3 It is a cross-sectional view of an adhesive protective film according to one or more other embodiments.

[0145] refer to Figure 3 The adhesive protective film may include a base layer 10, an adhesive film 20 and a release film 40 sequentially laminated on a first surface of the base layer 10, and a protective layer 30 laminated on a second surface of the base layer 10.

[0146] Figure 4 This figure illustrates a portion of the process of assembling a panel for an optical display device using an adhesive protective film according to one or more embodiments.

[0147] refer to Figure 4 A temporary upper protective film 2 and an adhesive protective film A, according to one or more embodiments, are respectively laminated onto the upper and lower surfaces of a panel 1 (e.g., a polyimide panel) on which OLED light-emitting elements are formed, to manufacture a laminate (I).

[0148] By using a laser to pattern the laminate, the adhesive protective film A is patterned into a portion Aa retained in the laminate and a portion Ab(II) peeled off from the laminate.

[0149] The stripped portion Ab of the stripped stack is irradiated with light and then cut with a laser to separate portion (III).

[0150] A small-sized laminate (a temporary upper protective film 2 and a portion Aa retained in the laminate, which are formed on the upper and lower surfaces of the panel 1 on which OLED light-emitting elements are formed, respectively) is obtained, and then a display driver 9 is installed to manufacture the panel (IV).

[0151] Next, a method for manufacturing a polyimide layer having a surface containing polyimide-based ash is described.

[0152] Figure 5 An exemplary embodiment of a method for manufacturing a polyimide layer having a polyimide-like ash is shown.

[0153] refer to Figure 5(1) Apply a polyimide-based varnish to the lower surface of the glass plate 100 to a set or predetermined thickness to create a polyimide-based varnish coating film 110.

[0154] (2) Dry and cure the manufactured polyimide varnish coating film 110 to form a polyimide layer 120 on the lower surface of the glass plate 100.

[0155] (3) When the laser radiation device 130 radiates a laser on the upper side of the glass plate 100, a polyimide gray 140 is formed on the upper surface of the polyimide layer 120.

[0156] Laser radiation can form polyimide ash by burning a portion of the polyimide layer 120. The polyimide ash can form fine steps (e.g., small step portions) between the laser-treated and non-laser-treated portions as irregular, fine, non-uniformities in the form of dust. These steps (e.g., step portions) can facilitate the peeling of the glass plate in the step (e.g., action or task) described below (4). The degree of formation of the polyimide ash 140 and / or the area ratio of the polyimide ash 140 formed therein (the ratio of the total area of ​​the polyimide ash to the total area of ​​the polyimide layer) can be controlled or selected based on the type or variety of the polyimide varnish, the total thickness of the polyimide layer, the degree of laser radiation, etc.

[0157] (4) The glass plate 100 can be peeled off from the polyimide layer 120 to create a polyimide layer 150 having a surface containing polyimide ash 140.

[0158] Figure 6 Another exemplary embodiment of a method for manufacturing a polyimide layer having a polyimide gray is shown.

[0159] refer to Figure 6 (1) Apply a polyimide varnish to the upper surface of the release substrate film 160 to a set or predetermined thickness to create a polyimide varnish coating film 110.

[0160] (2) Dry and cure the manufactured polyimide varnish coating film 110 to form a polyimide layer 120 on the upper surface of the release base film 160.

[0161] (3) Cover the upper surface of the polyimide layer 120 with a glass plate 100.

[0162] (4) When a laser is radiated on the upper side of the glass plate 100 using the laser radiating device 130, polyimide ash 140 is formed on the upper surface of the polyimide layer 120. The laser treatment can form polyimide ash by burning a portion of the polyimide layer. The polyimide ash can form fine steps (e.g., small step portions) between the laser-treated and non-laser-treated portions as irregular fine non-uniformities in the form of dust. The steps (e.g., step portions) can facilitate the peeling of the glass plate in the steps (e.g., actions or tasks) below (5). The degree of formation of polyimide ash 140 and / or the area ratio of polyimide ash 140 formed therein (the ratio of the total area of ​​polyimide ash to the total area of ​​the polyimide layer) can be controlled or selected according to the type or variety of polyimide varnish, the total thickness of the polyimide layer, the degree of laser radiating, etc.

[0163] (5) The glass plate 100 is peeled from the polyimide layer 120 to create a laminate of a release base film 160 and a polyimide layer 150 having a surface containing polyimide ash 140.

[0164] Since the release basement membrane 160 is released using silicone or the like, the release basement membrane 160 can be easily removed.

[0165] The glass sheet can be alkali-free glass and can have a thickness of 1 to 2 mm.

[0166] Polyimide varnishes may include 90% or more by weight of one or more selected from polyimide copolymers, polyimide oligomers, and polyimide monomers, but this disclosure is not limited thereto. For example, SD Flex (DuPont) can be used as a polyimide varnish, but this disclosure is not limited thereto.

[0167] Polyimide varnishes can be applied using methods suitable in the art. For example, they can be applied by blade coating. In this case, the gauge diameter can be 0.5 to 1.0 mm, for example, 0.65 mm. Polyimide varnishes can be applied to a thickness of 10 to 30 μm.

[0168] It can dry and cure polyimide varnish coatings to become polyimide layers.

[0169] Drying may include heat treatment at 50 to 200°C for 5 to 60 minutes. Drying may include one or more heat treatments, such as two or more heat treatments. In one or more embodiments, drying may include two or more heat treatments. For example, drying may include performing a first heat treatment at 50 to 100°C for 5 to 30 minutes and a second heat treatment at 100 to 200°C for 5 to 30 minutes. In one or more embodiments, the first heat treatment may be performed at 80°C for 10 minutes and the second heat treatment at 120°C for 20 minutes.

[0170] The dried product of polyimide varnish coating film can have a thickness of 20 to 30 μm, for example, 20 μm.

[0171] Compared to drying, curing can include heat treatment at relatively high temperatures for a relatively longer period of time. This heat treatment can imidize the dried products of a polyimide varnish coating film to create a polyimide layer. The heat treatment can include heat treatment at temperatures 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 can be performed once or multiple times. In one or more embodiments, curing can include heat treatment at 250°C for 60 minutes.

[0172] The polyimide layer can have a thickness of 20 to 30 μm, for example, 20 μm.

[0173] Laser radiation can range from 100 to 500 mJ / cm 2 For example, 150 to 200 mJ / cm 2 The amount of light emitted. If the light intensity is within the above range, a polyimide-based ash that is easily or suitable for peeling off from the glass plate can be formed. Laser radiation includes light radiation at a wavelength of 308 nm, and may include picosecond, nanosecond, and / or femtosecond radiation.

[0174] One or more embodiments of this disclosure relate to optical components.

[0175] The optical component may include a polyimide optical element having a polyimide gray on at least one surface and an adhesive protective film laminated on the surface having the polyimide gray, wherein the adhesive protective film includes a base layer, a photocurable product of the adhesive film laminated on a first surface of the base layer, and a protective layer laminated on a second surface of the base layer, and the protective layer comprises a silicon-based compound and has a pencil hardness value of F to H and a water contact angle value of 90° to 100° at 23°C.

[0176] Optical components may include the photocured product of the adhesive film described above.

[0177] In one or more embodiments, the polyimide optical element can be a flexible substrate. The flexible substrate can be used to support optical elements such as organic light-emitting diodes.

[0178] Any suitable optical element can be further laminated onto at least one surface of a polyimide-based optical element. Such an optical element can provide certain optical functions of an optical display device, such as light emission, polarization, optical compensation, improved image quality, and / or conductivity. Optical elements may include OLED elements, window films, windows, polarizing plates, color filters, phase contrast films, elliptical polarizing films, reflective polarizing films, anti-reflective films, compensation films, brightness enhancement films, alignment films, light diffusion films, anti-glass scattering films, surface protective films, OLED element blocking 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, graphene, etc.

[0179] Figure 7 This is a cross-sectional view of an exemplary embodiment of an optical component.

[0180] refer to Figure 7 The optical component includes a polyimide optical element 100 having a polyimide gray on its lower surface and an adhesive protective film laminated on the lower surface of the polyimide optical element 100, wherein the adhesive protective film may include a base layer 10, a cured product 21 of the adhesive film laminated on a first surface of the base layer 10, and a protective layer 30 laminated on a second surface of the base layer 10.

[0181] One or more embodiments of this disclosure relate to optical display devices.

[0182] Optical display devices include the optical components described above.

[0183] Optical display devices can include organic light-emitting element display devices, liquid crystal display devices, etc. Optical display devices can include flexible display devices. However, optical display devices can also include non-flexible display devices.

[0184] The construction and operation of this disclosure will be described in more detail below through embodiments thereof. However, it should be understood that these embodiments are provided as examples of this disclosure and should not be construed as limiting this disclosure in any way.

[0185] Example 1

[0186] (1) Preparation of compositions for adhesive films

[0187] Ethyl acetate solvent is added to a 1 L reactor equipped with a cooling device for reflux nitrogen and easy or appropriate temperature control. 100 parts by weight of a monomer mixture comprising 97 mol% n-butyl acrylate (homopolymer glass transition temperature: -45°C) and 3 mol% 4-hydroxybutyl acrylate is added to the reactor. Nitrogen is introduced into the monomer mixture for 30 minutes to remove oxygen, and then the internal temperature of the reactor is maintained at 62°C. The monomer mixture is stirred uniformly (e.g., substantially uniformly), 0.07 parts by weight of the initiator azobisisobutyronitrile is added, and the mixture is reacted at 62°C for 8 hours to produce a (meth)acrylate copolymer (weight average molecular weight: 1,000,000 g / mol). Ethyl acetate solvent is added to prepare a (meth)acrylate copolymer solution (solids content (e.g., amount): 24% by weight).

[0188] Based on the solids content, as shown in Table 1, 0.9 parts by weight of TD-75 (isocyanate-reactive curing agent; Soken; solids content (e.g., amount): 75% by weight), 1.0 parts by weight of BXX-4805 (aluminum chelate curing agent; Samyoung Ink & Coatings; solids content (e.g., amount): 5% by weight) as curing agents, 28.8 parts by weight of phenoxybenzyl acrylate (homopolymer glass transition temperature: 6°C; HanNong Chemicals Inc.) as an aromatic monofunctional monomer, and 0.6 parts by weight of Irgacure TPO (BASF, phosphorus photoinitiator) as a photoinitiator were added to 100 parts by weight of the (meth)acrylate copolymer prepared in the preparation example. Then, methyl ethyl ketone was added and diluted to prepare a composition for adhesive films (solids content (e.g., amount): 25% by weight).

[0189] (2) Preparation of the composition for the protective layer

[0190] Prepare the composition for the protective layer in the following order.

[0191] First, 60 parts by weight of urethane dimethacrylate (UDMA, Merck), 25.7 parts by weight of triethylene glycol dimethacrylate (TEGDMA, Merck), 3 parts by weight of long-wavelength photoinitiator TPO (IGM Resins), and 1 part by weight of short-wavelength photoinitiator I-184 (IGM Resins) were dissolved in a solvent to prepare a base composition A with a solid content (e.g., amount) of 50% by weight. Here, 45 parts by weight each of methyl ethyl ketone (MEK) and toluene were used as solvents.

[0192] As a leveling agent, 0.12% by weight of a silicone-based compound (BYK-UV 3505) is added to 100 parts by weight of the prepared base composition A, and the total solids content (e.g., amount) in the composition for the protective layer is adjusted to 30% by weight by adjusting the amount of solvent.

[0193] (3) Manufacturing of adhesive protective film

[0194] Polyethylene terephthalate (PET) film (Mitsubishi Chemical Corporation (MCC), T914J75, thickness: 75 μm) was prepared as the substrate layer. One surface of the PET film was coated using a doctor blade coater with the composition for the protective layer, dried at 85°C for 2 minutes, and then exposed to a mercury lamp at 300 mJ / cm². 2 (Under UV-A) to form a protective layer 1 μm thick.

[0195] Next, the prepared composition for the adhesive film was applied to another surface of the PET film to a thickness of 13 μm and dried at 110°C for 4 minutes. Then, a release film (thickness: 25 μm, with silicone release-treated on one surface, MHF25, MCC) was bonded to the obtained adhesive layer and placed at 50°C for 3 days to manufacture a sheet including an adhesive protective film, wherein the adhesive film and the release film are sequentially laminated on a first surface of the substrate layer and a protective layer is formed on a second surface of the substrate layer.

[0196] Examples 2 to 8

[0197] The sheet comprising the adhesive protective film was manufactured in essentially the same manner as in Example 1, except that the content (e.g., amount) of the silicon-based compound in the protective layer and / or the thickness of the protective layer were varied as shown in Table 1.

[0198] Comparative Example 1

[0199] The sheet comprising the adhesive protective film was manufactured in essentially the same manner as in Example 1, except that 0.2% by weight of a compound containing OH groups (BYK-SILCLEAN 3700) was added to the protective layer instead of the silicon-based compound.

[0200] Comparative Example 2

[0201] The sheet comprising the adhesive protective film was manufactured in essentially the same manner as in Example 1, except that a non-silicone compound containing acryloyl groups (BKK-UV3535) was used in the protective layer at a content of 0.2% by weight (e.g., amount) instead of a silicon-based compound.

[0202] The selected physical properties of the sheets including the adhesive protective film manufactured in the examples and comparative examples were evaluated. The results are shown in Table 1.

[0203] Reference Example: Fabrication of a polyimide layer having a polyimide gray on a surface

[0204] To manufacture a polyimide layer with a polyimide gray on a surface.

[0205] A polyimide varnish (SD Flex, DuPont) is applied to the upper surface of an alkali-free glass plate (thickness: 1.1 mm) to a thickness of up to 20 μm using a doctor blade coating device (reference diameter: 0.65 mm) to create a polyimide varnish coating film.

[0206] The polyimide varnish coating film was heat-treated at 80°C for 10 minutes and then at 120°C for 20 minutes to produce a dried product of the polyimide varnish coating film (thickness: 20 μm).

[0207] The dried product of the polyimide varnish coating film was cured at 250°C for 60 minutes in a high-temperature room to produce a laminate of a polyimide layer (thickness: 20 μm) and a glass plate.

[0208] The laser irradiation device (Micro Lens Arrays (MicroLAS), COHERENT) is positioned on the upper side of the glass plate of the laminate, and laser light is irradiated while the laminate is moved from one direction to another. The laser irradiation conditions are a wavelength of 308 nm, a femtosecond wavelength, and a light intensity of 170 mJ / cm². 2 .

[0209] After holding the laminate at room temperature for 1 hour, the glass plate is peeled off to create a polyimide layer with a polyimide gray on one surface.

[0210] Measurement of peel strength of adhesive film

[0211] In the optical components manufactured in the examples and comparative examples, a polyimide layer with polyimide ash was laminated onto the upper surface of an adhesive film and pressed with a 2 kg roller to produce a sample. At this point, the surface with polyimide ash and the adhesive film are laminated.

[0212] Cut the specimens into 25 mm × 100 mm (width × length) dimensions. Place the specimens at 23°C and 50% relative humidity for 30 minutes. Based on Japanese Industrial Standard JIS Z2037, if (for example, when) the adhesive film is peeled from a surface with polyimide-based grease at a peel temperature of 25°C, a peel speed of 2400 mm / min, and a peel angle of 180°, the peel strength A is measured using a Texture Analyzer (TA Industry).

[0213] Then, the sample was irradiated with UV light at a wavelength of 393 nm and an intensity of 1,000 mJ, and the peel strength B was measured using the same method.

[0214] Therefore, it can be seen that the peel strength B is higher than the peel strength A.

[0215] Scratch resistance as tested by steel wool:

[0216] In the sheets including the adhesive protective film manufactured in the examples and comparative examples, the release film was peeled off to expose the protective layer, and a 50 μm thick polyimide film and a 100 μm thick glass plate were sequentially laminated on the lower surface of the adhesive film to manufacture a sample.

[0217] The manufactured specimen is positioned with the protective layer facing upwards, and the number of scratches that occur when the specimen is refracted (e.g., moved back and forth) 5 times at a reciprocating speed of 4,000 mm / min under a load of 5 N is evaluated. No scratches are marked with ◎, 1 to 5 scratches with ○, 6 to 20 scratches with △, and more than 20 but less than 100 scratches with X.

[0218] Pencil hardness

[0219] The pencil hardness of the sheets containing the adhesive protective film manufactured in the examples and comparative examples was measured according to ASTM D3363 film hardness evaluation test at 23°C and 50% relative humidity. The specimens were cut to 50 mm × 50 mm dimensions, and the adhesive surface of the specimens was laminated onto a glass plate. The protective layer of the specimen was then used as the measurement area, and the pencil hardness was measured at 5 N and a speed of 48 mm / min.

[0220] Water contact angle of the protective layer (unit: °):

[0221] The sheets containing the adhesive protective film manufactured in the examples and comparative examples were cut to a size of 30 mm × 100 mm to produce test specimens. In the test specimens, the surface of the protective layer was placed on the fixture of a contact angle measuring device (DSA100, KRÜSSS Scientific), and the water contact angle was measured 5 times at 23°C and 50% relative humidity to calculate the average value.

[0222] Peel strength of carrier membrane

[0223] In the sheets comprising the adhesive protective film manufactured in the examples and comparative examples, the carrier film was pressed onto the protective layer using a 2 kg roller at 23°C and 50% relative humidity, and then cut into 25 mm × 100 mm (width × length) dimensions to produce test specimens. After specimen production, the specimens were placed at 23°C and 50% relative humidity for 30 minutes. If (e.g., when) the carrier film of the sheet is peeled off at 25°C at a peel speed of 2,400 mm / min, the peel strength is evaluated using a tensile tester (Texture Analyzer, TA Industry) according to JIS Z 2037.

[0224] Stamping machinability

[0225] In the sheets including the adhesive protective film manufactured in the examples and comparative examples, the protective layer is provided facing upwards. The sheets are then cut using a wooden mold under a pressing pressure of 15 MPa and a speed of 5 m / min. The cross-sections of the cut specimens are visually observed on all four sides, regardless of quantity, and the presence of damage and / or burrs on each side is evaluated.

[0226] The evaluation criteria are as follows.

[0227] ◎ (Excellent): No damage or burrs on any of the four sides.

[0228] ○ (Good): One of the four sides has damage and / or burrs.

[0229] △ (Average): Two out of the four sides have damage and / or burrs.

[0230] × (Poor): All four sides have damage and / or burrs.

[0231] Reliability (60°C × 95% × 500 hours)

[0232] The adhesive surface of each sheet, including the adhesive protective film, manufactured in the examples and comparative examples was laminated onto the AshPI (grey PI) surface, pressed using a 2 kg roller, and then cut into 150 mm × 90 mm dimensions.

[0233] Next, the cut sheets were placed at 23°C and 50% relative humidity for 30 minutes and then pressed. Afterwards, they were exposed to UV light at 1000 mJ / cm². 2 The substrate surface of the radiation sheet is used to manufacture test specimens for evaluating durability and reliability.

[0234] After placing the manufactured sample at 60°C × 95% for 500 hours, observe and evaluate the occurrence of bubbles, stains (migration), etc.

[0235] The evaluation criteria are as follows:

[0236] ◎: Completely free of bubbles or spots

[0237] ○: One or fewer bubbles and / or spots

[0238] △: 3 or fewer bubbles and / or spots

[0239] ×: More than 3 bubbles and / or spots

[0240] Module manufacturability - S / C defect incidence rate (unit: %)

[0241] For the sheets including the adhesive protective film manufactured in the embodiments and comparative examples, scratches and cracks (S / C) were confirmed to be present by direct visual inspection during the process.

[0242] Table 1

[0243]

[0244] As shown in Table 1 above, it can be seen that the adhesive protective films according to Examples 1 to 8 are superior in terms of stamping processability, reliability, and S / C occurrence rate compared to the adhesive protective films according to the comparative examples. Furthermore, the evaluation results from the steel wool test, pencil hardness, and water contact angle characteristics show that the adhesive protective films according to Examples 1 to 8 have excellent or adequate scratch resistance. In one or more embodiments, it can be seen that the presence or absence of a carrier film can be selected during the process because even when the adhesive protective film is attached to a carrier film, the peel strength of the carrier film meets a set or predetermined level.

[0245] This disclosure provides an adhesive protective film that can be adhered to a polyimide optical element having a polyimide ash, exhibits significantly higher peel strength after light irradiation than before light irradiation, and can be fixed to the optical element to improve the durability and reliability of the optical element.

[0246] This disclosure can provide an adhesive protective film that can be used together (e.g., simultaneously) as a temporary processing protective film in a flexible light-emitting element panel substrate and a pattern-enhancing protective film that is selectively peeled off only a portion to form a pattern.

[0247] This disclosure can provide an adhesive protective film that has excellent or suitable scratch resistance and excellent or suitable panel manufacturing processability when the adhesive protective film is used.

[0248] The above description is of some embodiments of this disclosure and should not be construed as limiting it. Although some embodiments have been described, it will be readily understood by those skilled in the art that various changes and modifications of this disclosure can be readily implemented, and all such changes and modifications can be considered to be included within the scope of this disclosure as defined by the appended claims and their equivalents.

Claims

1. An adhesive protective film, comprising: basal layer; An adhesive film on the first surface of the substrate layer; and A protective layer on the second surface of the substrate layer. The adhesive film comprises (meth)acrylic copolymers, a curing agent, a monofunctional or hyperfunctional monomer containing aromatic groups, and an initiator. The protective layer contains a silicon-based compound and has a pencil hardness value of F to H and a water contact angle value of 90° to 100° at 23°C.

2. The adhesive protective film according to claim 1, wherein, The thickness ratio of the base layer to the protective layer is from 10:1 to 200:

1.

3. The adhesive protective film according to claim 2, wherein, The protective layer has a thickness of 0.5 micrometers or greater and less than 5.0 micrometers.

4. The adhesive protective film according to claim 1, wherein, The protective layer is directly on the second surface of the base layer.

5. The adhesive protective film according to claim 1, wherein, The protective layer is formed by applying a composition for the protective layer to the second surface of the substrate and subjecting the composition for the protective layer to a curing process, and the composition for the protective layer comprises an adhesive and the silicone-based compound.

6. The adhesive protective film according to claim 5, wherein, The amount of the silicon-based compound relative to the composition used for the protective layer is 0.1% to 0.4% by weight.

7. The adhesive protective film according to claim 5, wherein, The adhesive includes one or more selected from urethane resins and urethane (meth)acrylate resins.

8. The adhesive protective film according to claim 1, further comprising a carrier film on the protective layer, in, The carrier membrane has a peel strength of 9 to 13 gf / inch.

9. The adhesive protective film according to claim 1, further comprising a release film on one surface of the adhesive film. in, The adhesive film is located between the release membrane and the base layer.

10. The adhesive protective film according to claim 1, wherein, If the initial peel strength of the adhesive film relative to the surface containing the polyimide ash is A, and after laminating the adhesive film onto the surface having the polyimide ash and irradiating it with light, the peel strength of the adhesive film relative to the surface containing the polyimide ash is B, then expression 1 is satisfied: Expression 1 A <B。 11. An optical component, comprising: A polyimide optical element, wherein the polyimide optical element comprises a polyimide ash on at least one surface, and An adhesive protective film is applied to a surface containing the polyimide-based ash. The adhesive protective film includes a base layer, an adhesive film on a first surface of the base layer, and a protective layer on a second surface of the base layer. The adhesive film comprises a cured product of a composition, the composition comprising a (meth)acrylic copolymer, a curing agent, an aromatic monofunctional or hyperfunctional monomer, and an initiator, and The protective layer contains a silicon-based compound and has a pencil hardness value of F to H and a water contact angle value of 90° to 100° at 23°C.

12. An optical display device comprising the optical component of claim 11.

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