KR102171407B1 - Adhesive protective film and optical member comprising the same - Google Patents

Abstract

A (meth)acrylic monomer mixture, a partial polymer thereof, or a (meth)acrylic copolymer thereof; Crosslinking agent; And as a pressure-sensitive adhesive protective film formed of a pressure-sensitive adhesive composition comprising a monofunctional (meth) acrylate modified with siloxane, wherein the pressure-sensitive adhesive protective film has a peel force of 5 gf/in or less to a glass plate at 25°C, and the adhesive protective film is That which satisfies Equation 1, an adhesive protective film and an optical member including the same are provided.

Description

An adhesive protective film and an optical member including the same TECHNICAL FIELD [ADHESIVE PROTECTIVE FILM AND OPTICAL MEMBER COMPRISING THE SAME}

The present invention relates to an adhesive protective film and an optical member including the same.

The optical display device includes a display device including an organic light emitting device or the like. Conventional organic light emitting devices include a glass plate as a substrate. However, recently, interest in wearable or foldable devices is increasing. In line with this interest, attempts to replace the substrate of the organic light-emitting device with a polyimide film in a glass plate are in progress.

The polyimide film is thinner and more flexible than the glass plate. The panel of the polyimide film substrate has poor mechanical properties and needs to be protected with a protective film in the optical display device manufacturing process. There is a limit to using the conventional protective film for protecting the glass plate as a protective film for the polyimide film. When the protective film protecting the polyimide film is removed from the polyimide film, if the peeling force is high, the panel including the polyimide film may be damaged. In particular, since the polyimide film is more flexible than the glass plate, it is easily damaged when the protective film is peeled off. Accordingly, a protective film capable of reducing damage or change in shape to a panel including a polyimide film is required even when peeling from the polyimide film due to low peeling force to the polyimide film.

Background art of the present invention is disclosed in Korean Patent Publication No. 2007-0055363.

The object of the present invention is excellent in adhesion to the substrate so that bubbles do not occur when adhering to the substrate, and the peeling force against the substrate is low, so that damage to the substrate and/or deformation of the appearance of the substrate when peeling from the substrate after being adhered to the substrate is prevented. It is to provide an adhesive protective film that can be prevented.

The adhesive protective film of the present invention includes a (meth)acrylic monomer mixture, a partial polymer thereof, or a (meth)acrylic copolymer thereof; Crosslinking agent; And it is formed of a pressure-sensitive adhesive composition comprising a monofunctional (meth)acrylate modified with siloxane, the adhesive protective film has a peel force of 5gf/in or less to the glass plate at 25°C, and the adhesive protective film has the following formula 1 You can be satisfied:

[Equation 1]

0≤ G/P ≤ 2

(In Equation 1, G is the indentation modulus (unit: MPa) at 25° C. of the adhesive protective film, and P is the peel force on the glass plate at 25° C. of the adhesive protective film (unit: gf/in)).

The optical member of the present invention may include an optical film and an adhesive protective film of the present invention formed on at least one surface of the optical film.

The present invention has excellent adhesion to the substrate, so that bubbles do not occur when adhering to the substrate, and the peeling force to the substrate is low, so it is possible to prevent damage to the substrate and/or deformation of the appearance of the substrate when peeling from the substrate after being adhered to the substrate. A sticky protective film was provided.

It will be described in detail so that those skilled in the art can easily implement the present invention by the following examples. The present invention may be implemented in various different forms, and is not limited to the embodiments described herein.

In the present specification, "(meth)acrylic" may mean acrylic and/or methacrylic. In the present specification, "copolymer" may include oligomers, polymers, or resins.

Hereinafter, an adhesive protective film according to an embodiment of the present invention will be described.

The adhesive protective film has a peel force of 5 gf/in or less on the glass plate at 25° C., and the adhesive protective film may satisfy Equation 1 below:

[Equation 1]

0≤ G/P ≤ 2

(In Equation 1 above,

G is the indentation modulus at 25° C. of the adhesive protective film (unit: MPa),

P is the peel force (unit: gf/in) of the adhesive protective film against the glass plate at 25°C.

In the range of the peeling force to the glass plate, the peeling force to the substrate (eg, glass plate, plastic film, etc.) is low, so that when the adhesive protective film is peeled from the substrate, damage to the substrate and/or deformation of the outer shape of the substrate can be prevented. When the adhesive protective film satisfies Equation 1, it has excellent adhesion to the substrate, so that bubbles or the like do not occur when adhering to the substrate. For example, the value G/P (ratio of indentation modulus to peeling force) of Equation 1 may be 0.1 to 2, 0.5 to 2, and 0.55 to 2. Through this, the adhesive protective film can be used for protecting a flexible display panel including a polyimide film. That is, the adhesive protective film has good adhesion when adhering to the display panel, so that air bubbles or the like may not occur. When bubbles or the like occur when the adhesive protective film is adhered to the display panel, there may be a problem of bubble transfer to the panel and process progress. In addition, since the peeling force with respect to the display panel is low, damage and/or deformation of the display panel may be prevented during peeling.

Formula 1 shows the ratio of the indentation modulus of the adhesive protective film to the peeling force of the adhesive protective film with respect to the glass plate. In general, since the peel force and modulus are in a trade-off relationship with each other, the modulus tends to decrease as the peel force increases and the modulus increases as the peel force decreases. The inventors of the present invention studied a method that can satisfy the above equation 1 by lowering the peel force of the adhesive protective film to 5 gf/in or less while relatively lowering the modulus, and as a result, the adhesive protective film described below is the range of the peel force. And it was confirmed that the above equation 1 can be satisfied at the same time.

In one embodiment, the adhesive protective film may have a peel force of 3 gf/in to 5 gf/in on the glass plate at 25°C.

The adhesive protective film may have an indentation modulus of 1 MPa to 10 MPa, for example, 5 MPa to 10 MPa and 6 MPa to 10 MPa at 25°C. In the above range, there may be an effect of implementing a low peel force.

The adhesive protective film includes (A) a (meth)acrylic monomer mixture, a partial polymer thereof, or a (meth)acrylic copolymer thereof; (B) crosslinking agent; And (C) is formed of a pressure-sensitive adhesive composition comprising a monofunctional (meth) acrylate modified with siloxane, each of the above-described components may be included in the content range detailed below. By satisfying Equation 1 in the above content range, the adhesion to the substrate is excellent, so that bubbles, etc. are not generated when adhering to the substrate, and the peeling force to the substrate is low, so that damage to the substrate and/or deformation of the appearance of the substrate upon peeling from the substrate is reduced. Can be prevented. The adhesive protective film includes (A) a (meth)acrylic monomer mixture, a partial polymer thereof, or a (meth)acrylic copolymer thereof; (B) crosslinking agent; And (C) a monofunctional (meth)acrylate modified with siloxane may be formed of a cured product crosslinked (cured) with each other.

The (meth)acrylic monomer mixture, a partial polymer thereof, or a (meth)acrylic copolymer thereof can form a matrix of an adhesive protective film and provide peeling force.

The (meth)acrylic monomer mixture may include an alkyl group-containing (meth)acrylate and a hydroxyl group-containing (meth)acrylate. Each of these may include one or two or more. The (meth)acrylic monomer may be a non-silicone monomer that does not contain silicone.

The alkyl group-containing (meth)acrylate can form a matrix of an adhesive protective film. The alkyl group-containing (meth)acrylate may include a (meth)acrylic acid ester having an unsubstituted linear or branched alkyl group having 1 to 20 carbon atoms. In one embodiment, the alkyl group-containing (meth)acrylate may be a non-silicone-based (meth)acrylate that does not contain silicone. For example, the alkyl group-containing (meth)acrylate is methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, t-butyl (meth)acrylate. , iso-butyl (meth)acrylate, pentyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, ethylhexyl (meth)acrylate, octyl (meth)acrylate, isooctyl (meth)acrylate ) At least one of acrylate, nonyl (meth)acrylate, decyl (meth)acrylate, lauryl (meth)acrylate, isobornyl (meth)acrylate, and ethylhexyldiglycol (meth)acrylate Can include.

In one embodiment, the glass transition temperature of the homopolymer of the alkyl group-containing (meth)acrylate may be -100°C to -5°C, preferably -70°C to -10°C. In the above range, there may be a good effect of wettability and adhesion to the adherend. For example, the alkyl group-containing (meth)acrylate may include at least one of 2-ethylhexyl acrylate, butyl acrylate, isooctyl acrylate, and ethylhexyldiglycol (meth)acrylate.

The alkyl group-containing (meth)acrylate may be included in an amount of 50% to 99% by weight, preferably 50% to 98% by weight, and 65% to 98% by weight of the (meth)acrylic monomer mixture. In the above range, the peeling force of the adhesive protective film to the glass plate is low, and the strength is excellent, so that it can be used as a substrate protection for optical elements.

The hydroxyl group-containing (meth)acrylate can provide peeling force to the adhesive protective film. The hydroxyl group-containing (meth)acrylate may be a (meth)acrylate containing one or more hydroxyl groups. In one embodiment, the hydroxyl group-containing (meth)acrylate may be a non-silicone-based (meth)acrylate that does not contain silicone. For example, the hydroxyl group-containing (meth)acrylate is 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-hydroxybutyl (Meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 1,4-cyclohexanedimethanol mono (meth)acrylate, 1-chloro-2-hydro Roxypropyl (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-phenyloxypropyl(meth)acrylate, 4- It may be one or more of hydroxycyclopentyl (meth)acrylate, 4-hydroxycyclohexyl (meth)acrylate, and cyclohexanedimethanol mono (meth)acrylate. Preferably, the hydroxyl group-containing (meth)acrylate is 4-hydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, and 4-hydroxypropyl. It may include one or more of (meth)acrylate.

The hydroxyl group-containing (meth)acrylate may be included in an amount of 1% to 50% by weight, preferably 2% to 50% by weight, and 2% to 35% by weight of the (meth)acrylic monomer mixture. In the above range, the peeling force of the adhesive protective film to the glass plate is low, and the rate of change of haze is low, so that reliability may be excellent.

In another embodiment, the (meth)acrylic monomer mixture may include other copolymerizable (meth)acrylic monomers in addition to the alkyl group-containing (meth)acrylate and the hydroxyl group-containing (meth)acrylate. Other copolymerizable (meth)acrylic monomers are non-silicone monomers that do not contain silicone, and are (meth)acrylates having an alicyclic group, (meth)acrylates having a heteroalicyclic group, and (meth)acrylates having an aromatic group, It may include one or more of the (meth)acrylic monomers having a carboxylic acid group, but is not limited thereto.

The (meth)acrylic monomer mixture may be included in the pressure-sensitive adhesive composition as a (meth)acrylic monomer mixture itself, but it is preferably included as a (meth)acrylic-based copolymer to increase the strength of the adhesive protective film, and the target peel strength and formula You can make it reach a value of 1.

The (meth)acrylic copolymer can be prepared by polymerizing a (meth)acrylic monomer mixture by a conventional method, and the polymerization method may be according to a conventional method known to those skilled in the art.

The (meth)acrylic copolymer may have a weight average molecular weight of 1 million to 2 million, preferably 1.3 million to 1.7 million. In the above range, there may be an effect of improving peel strength and wettability.

(A) (meth)acrylic monomer mixture, a partial polymer thereof, or a (meth)acrylic copolymer thereof is a total of (A), (B), (C) (A) + (B) + (C) 100 parts by weight It may be included in 65 parts by weight to 98 parts by weight. In the above range, low peel strength and improved wettability It can work. Preferably, it may be included in an amount of 65 to 95 parts by weight and 80 to 90 parts by weight.

The crosslinking agent may include a non-silicone-based crosslinking agent that does not contain silicone. The crosslinking agent may include a non-silicone-based polyfunctional (meth)acrylate that can be cured with an active energy ray. The crosslinking agent may include a non-isocyanate type crosslinking agent that does not contain an isocyanate group. In a specific embodiment, the crosslinking agent is a di(meth)acrylate having a C1 to C10 alkylene group such as 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, dipropylene glycol Di(meth)acrylate, neopentyl glycol di(meth) having a C1 to C10 alkylene group having a C1 to C3 alkyleneoxy group including di(meth)acrylate, polyethylene glycol di(meth)acrylate, etc. Acrylate, neopentyl glycol adipate di(meth)acrylate, dicyclopentanyl di(meth)acrylate, caprolactone-modified dicyclopentenyl di(meth)acrylate, ethylene oxide-modified di(meth)acrylate, Di(meth)acryloxy ethyl isocyanurate, allylated cyclohexyl di(meth)acrylate, tricyclodecanedimethanol(meth)acrylate, dimethylol dicyclopentanedi(meth)acrylate, ethylene oxide modified Hexahydrophthalic acid di(meth)acrylate, tricyclodecane dimethanol(meth)acrylate, neopentyl glycol modified trimethylpropane di(meth)acrylate, adamantane di(meth)acrylate or 9,9 -Bifunctional acrylates such as bis[4-(2-acryloyloxyethoxy)phenyl]fluorene and the like; Trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid-modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide Trifunctional acrylates such as modified trimethylolpropane tri(meth)acrylate, trifunctional urethane (meth)acrylate, or tris(meth)acryloxyethyl isocyanurate; Tetrafunctional acrylates such as diglycerin tetra(meth)acrylate or pentaerythritol tetra(meth)acrylate; 5-functional acrylates such as dipentaerythritol penta(meth)acrylate; And dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate or urethane (meth)acrylate (ex. of isocyanate monomer and trimethylolpropane tri(meth)acrylate) 6-functional acrylates such as reactants may be mentioned, but are not limited thereto. These may be used alone or in combination of two or more.

For example, the crosslinking agent is one of di(meth)acrylate having a C1 to C10 alkylene group, and di(meth)acrylate having a C1 to C10 alkylene group having a C1 to C3 alkyleneoxy group. It may include more than one.

In one embodiment, the crosslinking agent may be a di(meth)acrylate having a C1 to C10 alkylene group.

In another embodiment, the crosslinking agent may be a mixture of a di(meth)acrylate having a C1 to C10 alkylene group and a di(meth)acrylate having a C1 to C10 alkylene group having a C1 to C3 alkyleneoxy group. . At this time, based on 100 parts by weight of the mixture, the di(meth)acrylate having a C1 to C10 alkylene group is 50 to 90 parts by weight, preferably 55 to 80 parts by weight, having a C1 to C3 alkyleneoxy group. The di(meth)acrylate having a C1 to C10 alkylene group may be included in an amount of 10 parts by weight to 50 parts by weight, preferably 20 parts by weight to 45 parts by weight.

The crosslinking agent may be included in an amount of 1 to 5 parts by weight of 100 parts by weight of (A)+(B)+(C). In the above range, there may be an effect of improving peel strength and wettability. Preferably it may be included in 3 parts by weight to 5 parts by weight.

The monofunctional (meth)acrylate modified with siloxane may include a compound in which the ester moiety of the monofunctional (meth)acrylate is modified with siloxane. Monofunctional (meth)acrylate modified with siloxane may be included alone or two or more of the adhesive protective films. In one embodiment, the monofunctional (meth)acrylate modified with siloxane may be a non-particulate compound rather than a particulate. Through this, it is possible to prevent an increase in modulus of the adhesive protective film. The monofunctional (meth)acrylate modified with the siloxane may include a polydialkylsiloxane moiety as the siloxane.

In one embodiment, the monofunctional (meth)acrylate modified with siloxane may be represented by the following Formula 1:

<Formula 1>

(In Formula 1, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or 6 To 10 aryl group, R ₈ is an alkylene group having 1 to 10 carbon atoms, or an arylene group having 6 to 10 carbon atoms, R ₉ is hydrogen or a methyl group, n is an integer of 10 to 100).

Preferably, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ are each independently a methyl group, an ethyl group as an alkyl group having 1 to 10 carbon atoms, more preferably an alkyl group having 1 to 5 carbon atoms , It may be a propyl group, a butyl group, or a pentyl group. Preferably, R ₈ may be an alkylene group having 1 to 5 carbon atoms, more preferably a methylene group, an ethylene group, a propylene group, a butylene group or a pentylene group. Preferably, n may be an integer of 20 to 80, more preferably an integer of 20 to 70.

In one embodiment, the monofunctional (meth)acrylate modified with siloxane may be represented by the following Formula 1-1:

<Formula 1-1>

(In Formula 1-1, R ₂ is an alkyl group having 1 to 10 carbon atoms, R ₈ is an alkylene group having 1 to 10 carbon atoms, or an arylene group having 6 to 10 carbon atoms, R ₉ is a hydrogen or methyl group, n is 10 to 100 Integer).

The monofunctional (meth)acrylate modified with siloxane may have a weight average molecular weight of 1000 to 6000, preferably 3000 to 6000. Monofunctional (meth)acrylate modified with siloxane may have a homopolymer glass transition temperature of -150°C to -10°C, preferably -100°C to -20°C. In the above range, there may be a good effect of wettability and adhesion to the adherend.

The monofunctional (meth)acrylate modified with siloxane may be included in an amount of 1 to 30 parts by weight of 100 parts by weight of (A) + (B) + (C). In the above range, there may be a good effect of wettability and adhesion to the adherend. Preferably it may be included in 5 parts by weight to 15 parts by weight.

In one embodiment, the pressure-sensitive adhesive composition is (A) 65 parts by weight to 87 parts by weight, (B) more than 0 parts by weight and less than 7 parts by weight based on 10 parts by weight of the monofunctional (meth)acrylate modified with (C) siloxane Can be included. In the above range, the peel force range of the present invention can be reached and the value of Equation 1 can be satisfied. Preferably, (C) 67 parts by weight to 87 parts by weight, (B) 1 to 5 parts by weight, preferably 3 parts by weight, based on 10 parts by weight of the monofunctional (meth)acrylate modified with siloxane It may be included in to 5 parts by weight.

In another embodiment, the total of (B) and (C) in the pressure-sensitive adhesive composition may be included in an amount of more than 0 parts by weight and 15 parts by weight or less among 100 parts by weight of (A) + (B) + (C). In the above range, the peel force range of the present invention can be reached and the value of Equation 1 can be satisfied. Preferably, the total sum of (B) and (C) is 5 parts by weight to 15 parts by weight, 11 parts by weight to 15 parts by weight, 12 parts by weight of 100 parts by weight of (A) + (B) + (C) It may be included in to 15 parts by weight.

The pressure-sensitive adhesive composition may further include an initiator.

The initiator may be used to cure (partially polymerize) the monomer mixture with a (meth)acrylic prepolymer or to cure a viscous liquid containing the prepolymer into an adhesive film. The initiator may include at least one of a photopolymerization initiator and a thermal polymerization initiator.

As the photoinitiator, any can be used as long as it can induce the polymerization reaction of the radical polymerizable compound described below in the curing process by light irradiation or the like. For example, benzoin-based, hydroxy ketone-based, amino ketone-based, or phosphine oxide-based photoinitiators may be used, but the present invention is not limited thereto. As the thermal polymerization initiator, for example, a conventional initiator such as an azo compound, a peroxide compound, or a redox compound may be used. The initiator may be included in an amount of 0.0001 to 5 parts by weight, preferably 0.001 to 3 parts by weight, and more preferably 0.001 to 1 part by weight, based on 100 parts by weight of the (meth)acrylic monomer mixture. In the above range, the curing reaction may completely proceed, the remaining amount of the initiator may be prevented from deteriorating the transmittance, and the generation of bubbles may be reduced, and excellent reactivity may be obtained.

The pressure-sensitive adhesive composition is an antistatic agent, a surfactant, a curing accelerator, an ionic liquid, a lithium salt, an inorganic filler, a softener, a molecular weight control agent, an antioxidant, an anti-aging agent, a stabilizer, a tackifier resin, and a modifying resin (polyol resin, phenol resin, acrylic resin. , Polyester resins, polyolefin resins, epoxy resins, epoxidized polybutadiene resins, etc.), leveling agents, defoaming agents, plasticizers, dyes, pigments (colored pigments, extender pigments, etc.), treatment agents, sunscreen agents, optical brighteners, dispersants , Thermal stabilizers, light stabilizers, UV absorbers, coagulants, lubricants, and may further include conventional additives such as solvents.

The additive may be included in an amount of 0.001 to 1 part by weight, specifically 0.003 to 1 part by weight, specifically 0.005 to 1 part by weight, based on 100 parts by weight of the (meth)acrylic monomer mixture. In the above range, it is possible to exert an additive effect without affecting the peel strength and reliability of the adhesive film.

The pressure-sensitive adhesive composition does not contain an isocyanate type thermosetting agent. When the pressure-sensitive adhesive composition includes an isocyanate-type thermosetting agent, it cannot be used because the peeling force on the polyimide film increases.

The adhesive protective film may have a total light transmittance of 90% or more, specifically 95% or more in a visible light region (eg, wavelength 380 nm to 780 nm). In the above range, optical transparency is good and can be used in an optical display device.

The adhesive protective film may have a thickness of 10 μm to 200 μm, preferably 25 μm to 75 μm. In the above range, it may be used by laminating on an optical film.

The adhesive protective film can be prepared by photocuring the adhesive composition. In the pressure-sensitive adhesive composition, the monomer mixture including the (meth)acrylic prepolymer may be included in the pressure-sensitive adhesive composition in the form of a monomer mixture that is not polymerized at all, but the monomer mixture may be included as a partially polymerized prepolymer.

The pressure-sensitive adhesive composition partially polymerizes a (meth)acrylic prepolymer with an initiator, and contains a monofunctional (meth)acrylate modified with an additional siloxane, a bifunctional (meth)acrylate modified with an additional siloxane, an additional initiator, an additional crosslinking agent, and an additional additive. It can be prepared by including. Partial polymerization may include solution polymerization, suspension polymerization, photopolymerization, bulk polymerization, or emulsion polymerization. Specifically, solution polymerization may be performed at 50 to 100°C by adding an initiator to the monomer mixture. As the initiator, photopolymerization initiators such as an acetophenone system including 2,2-dimethoxy-2-phenylacetophenone and the like and 1-hydroxycyclohexylphenyl ketone can be used. The partial polymerization can be polymerized with a viscosity of 1,000 cPs to 10,000 cPs, specifically, a viscosity of 4,000 cPs to 9,000 cPs at 25°C. The adhesive film can be manufactured by a conventional method. For example, it can be prepared by coating the pressure-sensitive adhesive composition on a release film and then curing it. Curing may include irradiation of the irradiation dose 400mJ / cm ² to 3000mJ / cm ² at a wavelength of 300nm to 400nm into a low-pressure lamp in an oxygen-free state.

The optical member according to an embodiment of the present invention includes an optical film and an adhesive protective film formed on at least one surface of the optical film, and the adhesive protective film may include an adhesive protective film according to embodiments of the present invention. .

The optical film may be a film formed of at least one of polyethylene terephthalate resin, polycarbonate resin, polyimide resin, poly(meth)acrylate resin, cyclic olefin polymer resin, and acrylic resin. The optical film may have a thickness of 50 μm to 250 μm, preferably 50 μm to 100 μm. In the above range, the adhesive protective film can be supported.

The optical member may further include a release film (liner) on the other side of the adhesive protective film. The release film can prevent the adhesive protective film from being contaminated by external foreign substances. As the release film, an optical film formed of the same or different material as the above-described optical film may be used. The release film may have a thickness of 10 μm to 100 μm, preferably 10 μm to 50 μm. In the above range, the adhesive protective film can be supported.

An optical member according to another embodiment of the present invention includes an optical film and an adhesive protective film formed on at least one surface of the optical film, and the adhesive protective film may include an adhesive protective film according to embodiments of the present invention. .

The optical film may be formed of a polyimide film as a display panel. In one embodiment, the optical film may be composed of a light emitting device layer and a polyimide film formed on at least one surface of the light emitting device layer. An organic insulating film or an inorganic insulating film may be further formed between the optical film and the adhesive protective film.

Hereinafter, the configuration and operation of the present invention will be described in more detail through preferred embodiments of the present invention. However, this is presented as a preferred example of the present invention and should not be construed as limiting the present invention in any sense.

The detailed composition of the components used in the following Examples and Comparative Examples is as follows.

(A) (meth)acrylic copolymer

(A1) (meth)acrylic copolymer: a copolymer of 97 parts by weight of 2-ethylhexyl acrylate and 3 parts by weight of 2-hydroxyethyl acrylate based on 100 parts by weight

(A2) (meth)acrylic copolymer: a copolymer of 90 parts by weight of 2-ethylhexyl acrylate and 10 parts by weight of 2-hydroxyethyl acrylate based on 100 parts by weight

(B) crosslinking agent

(B1) A mixture of 65 parts by weight of hexanediol diacrylate (Entis) and 35 parts by weight of dipropylene glycol diacrylate (Sartomer, SR508) based on 100 parts by weight

(B2) Hexanediol diacrylate (Entis)

(C) Monofunctional (meth)acrylate modified with siloxane: SM7515 (KCC, in Formula 1-1, R ₂ is a methyl group, R ₈ is an n-propylene group, R ₉ is a methyl group)

Example One

Based on solid content, 85 parts by weight of (A) (meth)acrylic copolymer, (B1) 5 parts by weight of a crosslinking agent, and (C) 10 parts by weight of monofunctional (meth)acrylate modified with siloxane were added and mixed to prepare a pressure-sensitive adhesive composition. .

After degassing the pressure-sensitive adhesive composition, apply it to one side of a release film, PET (polyethylene terephthalate) film (thickness: 75㎛, SKC), and then again, a release film, PET (polyethylene terephthalate) film (thickness: 25㎛, Toray Advanced Materials) ), then irradiated with a light amount of 2000 mJ/cm ² with ultraviolet light in a low-pressure mercury lamp, and irradiated with a light amount of 1 J/cm ² with a metal halide lamp, and PET film/adhesive protective film (thickness: 30 μm)/PET film A pressure-sensitive adhesive sheet was prepared.

Example 2 to Example 4

A pressure-sensitive adhesive sheet of a PET film/adhesive protective film/PET film was prepared in the same manner, except that the configuration of the pressure-sensitive adhesive composition in Example 1 was changed as shown in Table 1 (unit by weight).

Comparative example 1 to Comparative example 6

A pressure-sensitive adhesive sheet of a PET film/adhesive protective film/PET film was prepared in the same manner, except that the configuration of the pressure-sensitive adhesive composition in Example 1 was changed as shown in Table 1 (unit by weight).

The physical properties of Table 1 were evaluated for the adhesive sheets prepared in Examples and Comparative Examples, and the results are shown in Table 1 below.

(1) Modulus of the adhesive protective film (unit: MPa): Both PET films were released from the adhesive sheets of the PET film/adhesive protective film/PET film of Examples and Comparative Examples to obtain an adhesive protective film. The adhesive protective film was measured using a Nano indentor (Hysitron TI750). A portion of the adhesive protection film at 25 ℃ (sectional area: 1mm ²⁾ using nano-indenter (Viker particles) was added for 5 seconds with a force of up to 1000μN on (loading), held for 2 seconds, and (holding), for 5 seconds The modulus was measured by unloading.

(2) Peeling force (unit: gf/in): Both PET films were released from the adhesive sheets of the PET film/adhesive protective film/PET film of Examples and Comparative Examples to obtain an adhesive protective film. The adhesive protective film was cut into a rectangle with a width x length of 2.5 cm x 10 cm and adhered to a glass plate to prepare a specimen. The specimen was attached to the TA device, and the peel force was measured when the adhesive protective film was peeled from the glass plate by 180° at 25° C. at a peel rate of 300 mm/min.

(3) Adhesion to substrate: Both PET films were released from the adhesive sheets of the PET film/adhesive protective film/PET film of Examples and Comparative Examples to obtain an adhesive protective film. When the adhesive protective film was laminated to the glass plate, it was evaluated visually whether air bubbles were generated. When no air bubbles were generated, it was evaluated as good, and when a substrate was generated, it was evaluated as defective.

(A) (B) (C) Modulus Peeling force Equation 1 ratio Substrate adhesion Kinds content Kinds content content Example 1 (A1) 85 (B1) 5 10 8 4 2 Good Example 2 (A1) 85 (B2) 5 10 6.4 3.2 2 Good Example 3 (A1) 87 (B1) 3 10 8.5 4.3 1.98 Good Example 4 (A2) 85 (B1) 5 10 6.2 3.3 1.9 Good Comparative Example 1 (A1) 89.5 (B1) 0.5 10 3.4 6.5 0.52 Good Comparative Example 2 (A1) 80 (B2) 10 10 9.6 2.4 4 Bad Comparative Example 3 (A1) 83 (B1) 7 10 9.6 3.7 2.6 Bad Comparative Example 4 (A1) 75 (B1) 15 10 12.8 2.4 5.3 Bad Comparative Example 5 (A1) 85 (B1) 15 0 17.1 2.1 8.1 Bad Comparative Example 6 (A1) 85 (B1) 0 15 Not measurable Not measurable Not measurable Not measurable

As shown in Table 1 above, the adhesive protective film of the present invention has excellent adhesion to the substrate so that bubbles do not occur when adhering to the substrate, and the peeling force to the substrate is low, so that the substrate is adhered to the substrate and then removed from the substrate. Damage and/or external deformation of the substrate can be prevented.

On the other hand, Comparative Example 1, which does not satisfy the peel force range of the present invention, has a peel force of more than 5 gf/in and may cause damage to the substrate and/or deformation of the outer appearance of the substrate upon peeling after being adhered to the substrate. In addition, Comparative Examples 2 to 5, which do not satisfy Equation 1 of the present invention, had poor substrate adhesion.

Simple modifications or changes of the present invention can be easily implemented by those of ordinary skill in the art, and all such modifications or changes can be considered to be included in the scope of the present invention.

Claims (15)

(A) a (meth)acrylic monomer mixture, a partial polymer thereof, or a (meth)acrylic copolymer thereof; (B) crosslinking agent; And (C) as a pressure-sensitive adhesive protective film formed of a pressure-sensitive adhesive composition comprising a monofunctional (meth)acrylate modified with siloxane,
The adhesive protective film has a peel force of 5 gf/in or less with respect to the glass plate at 25° C.,
The adhesive protective film satisfies the following formula 1,
[Equation 1]
0≤ G/P ≤ 2
(In Equation 1 above,
G is the indentation modulus at 25° C. of the adhesive protective film (unit: MPa),
P is the peeling force of the adhesive protective film against the glass plate at 25°C (unit: gf/in)),
The peeling force against the glass plate at 25°C was obtained by attaching the adhesive protective film to a glass plate to prepare a specimen, and when the adhesive protective film was peeled 180° from the glass plate at 25°C at a peel rate of 300 mm/min. Peeling force,
The indentation modulus at 25° C. is applied to a portion of the adhesive protective film (cross-sectional area: 1 mm ² ) at 25° C. using a nano indenter (Viker particle) for 5 seconds with a force of up to 1000 μN (loading) for 2 seconds. Holding (holding) and removing (unloading) for 5 seconds to be measured modulus, the adhesive protective film.
The adhesive protective film of claim 1, wherein the adhesive protective film has an indentation modulus of 1 MPa to 10 MPa at 25°C.
The adhesive protective film according to claim 1, wherein the (meth)acrylic monomer mixture comprises an alkyl group-containing (meth)acrylate and a hydroxyl group-containing (meth)acrylate.
The method of claim 3, wherein the (meth)acrylic monomer mixture comprises 50% to 99% by weight of an alkyl group-containing (meth)acrylate and 1% to 50% by weight of a hydroxyl group-containing (meth)acrylate, Protective film.
The adhesive protective film of claim 1, wherein the (meth)acrylic copolymer has a weight average molecular weight of 1 million to 2 million.
The adhesive protective film of claim 1, wherein the crosslinking agent comprises a non-isocyanate type crosslinking agent.
The method of claim 1, wherein the crosslinking agent is one of di(meth)acrylate having a C1 to C10 alkylene group, and di(meth)acrylate having a C1 to C10 alkylene group having a C1 to C3 alkyleneoxy group. What contains the above, the adhesive protective film.
The adhesive protective film of claim 1, wherein the monofunctional (meth)acrylate modified with siloxane is a non-particulate compound.
The adhesive protective film according to claim 1, wherein the monofunctional (meth)acrylate modified with siloxane comprises a polydialkylsiloxane moiety.
The adhesive protective film of claim 1, wherein the monofunctional (meth)acrylate modified with siloxane is represented by the following formula (1):
<Formula 1>

(In Formula 1, R ₁ , R ₂ , R ₃ , R ₄ , R ₅ , R ₆ , R ₇ are each independently hydrogen, an alkyl group having 1 to 10 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or 6 To 10 aryl group, R ₈ is an alkylene group having 1 to 10 carbon atoms, or an arylene group having 6 to 10 carbon atoms, R ₉ is hydrogen or a methyl group, n is an integer of 10 to 100).
The method of claim 1, wherein the pressure-sensitive adhesive composition is based on 10 parts by weight of the (C) siloxane-modified monofunctional (meth)acrylate, the (A) (meth)acrylic monomer mixture, its partial polymer or its (meth) 65 parts by weight to 87 parts by weight of an acrylic copolymer, (B) 0 parts by weight of a crosslinking agent and less than 7 parts by weight of the adhesive protective film.
The method of claim 1, wherein the pressure-sensitive adhesive composition is based on 10 parts by weight of the (C) siloxane-modified monofunctional (meth)acrylate, the (A) (meth)acrylic monomer mixture, its partial polymer or its (meth) Acrylic-based copolymer 67 parts by weight to 87 parts by weight, (B) 3 to 5 parts by weight of a crosslinking agent, which is contained in the adhesive protective film.
The method of claim 1, wherein the total of (B) and (C) in the pressure-sensitive adhesive composition is the sum of (A), (B), (C) (A) + (B) + (C) 100 parts by weight The adhesive protective film that is contained in more than 0 parts by weight and 15 parts by weight or less.
delete Optical film; And
An optical member comprising the adhesive protective film of any one of claims 1 to 13 formed on one surface of the optical film.