JP2023548328A - Adhesive film, optical member including the same, and optical display device including the same - Google Patents

Abstract

An adhesive film containing a (meth)acrylic binder, a photoreactive monomer, and a photoinitiator, wherein the adhesive film has an adhesive force change rate of about 90% or more according to Formula 1, and a refractive index of about 90% or more. A pressure-sensitive adhesive film having a particle diameter of 1.55 or more, an optical member including the same, and an optical display device including the same are provided.
[Selection diagram] Figure 1

Description

The present invention relates to an adhesive film, an optical member including the same, and an optical display device including the same.

In an organic light-emitting element display device, 80% or more of the light emitted from the light-emitting layer is reflected or absorbed at the interface or inside of various layered structures of the light-emitting element or display device, and is not emitted to the front of the display device. Disappear. This reduces light extraction efficiency, resulting in increased power consumption to achieve a desired brightness, thereby shortening the lifespan of the light emitting device.

On the other hand, the touch screen panel laminated on the light emitting device is made of a metal material such as aluminum or titanium, and thus has a significantly higher refractive index than a typical adhesive film. Accordingly, in order to reduce the difference in refractive index between layers and increase light extraction efficiency, a method of further laminating a layer capable of alleviating the difference in refractive index or an adhesive film with a high refractive index may be considered.

A high refractive index adhesive film is manufactured in the form of an adhesive sheet in which a base film, a high refractive index adhesive film, and a release film are sequentially laminated, and then only the release film is peeled off. Laminated on. As the base film, a film that has not been subjected to release treatment may be used. When a release-treated film is used as the base film, the adhesive film may have a poor appearance. An assembly process using the adhesive sheet with an adherend including a display panel will be described with reference to FIG. 3.

Referring to FIG. 3, in (i), only the release film is peeled off from the adhesive sheet in which the base film 30, the high refractive index adhesive film 50, and the release film are sequentially laminated, and then the high refractive index Laminated into a display panel 10 containing functional layers. In (ii), the adherend 40 including an optical film or the like is laminated on the base film 30 using the adhesive film 60 as an intermediary. However, there is a problem in that the base film 30 and the adhesive film 60 increase the thickness of the optical display device.

The background technology of the present invention is disclosed in Korean Patent Publication No. 10-1189698.

An object of the present invention is to provide an adhesive film that has a high refractive index and has variable adhesive strength by UV irradiation.

Another object of the present invention is to provide an adhesive film that has a high refractive index and whose adhesive strength to a base film is significantly reduced by UV irradiation.

Still another object of the present invention is to provide a pressure-sensitive adhesive film that has a high refractive index, but whose adhesive strength to a substrate film is significantly reduced by UV irradiation and whose adhesive strength to an adherend is significantly increased.

Still another object of the present invention is to provide an adhesive film with excellent optical properties and step-filling properties.

Still another object of the present invention is to provide an adhesive film that can reduce the thickness of an optical display device.

One aspect of the present invention is an adhesive film.

1. The adhesive film includes a (meth)acrylic binder, a photoreactive monomer, and a photoinitiator, and the adhesive film has an adhesive force change rate of about 90% or more according to the following formula 1, and a refractive index of about 90% or more. 1.55 or more:

(In the above formula 1,
A is the adhesive force (unit: gf/inch) when peeling the base film from the adhesive film after laminating the laminate of the adhesive film and the base film on the glass plate;
B is the adhesive force (unit: gf/inch) when a laminate of an adhesive film and a base film is laminated on a glass plate and the base film is peeled from the adhesive film after UV irradiation).

In 2.1, A in the formula 1 may be about 1000 gf/inch or more, and B in the formula 1 may be about 100 gf/inch or less.

In 3.1-2, the adhesive film may have an adhesive force change rate of about 10% or more according to the following formula 2:

(In the above formula 2, C is the adhesive force (unit: gf/inch) of the adhesive film to the glass plate measured after laminating the laminate of the base film and the adhesive film on the glass plate,
D is the adhesive strength (unit: gf/inch) of the adhesive film to the glass plate after laminating the laminate of the base film and the adhesive film on the glass plate and irradiating it with UV.

4.3, C in the formula 2 may be about 500 gf/inch or more, and D in the formula 2 may be about 600 gf/inch or more.

In 5.1-4, the (meth)acrylic binder includes an aromatic group-containing (meth)acrylic monomer, a hydroxyl group-containing (meth)acrylic monomer, and an alkyl group-containing (meth)acrylic monomer. (meth)acrylic copolymers of monomer mixtures containing monomers.

In 6.1-5, the (meth)acrylic binder includes a (meth)acrylic copolymer of a monomer mixture, and of the monomer mixture, an aromatic group-containing (meth)acrylic monomer The content of the hydroxyl group-containing (meth)acrylic monomer is about 5% to about 30% by weight, and the alkyl group-containing (meth)acrylic monomer is about 30% to about 95% by weight. , from about 0% to about 40% by weight.

In 7.1-6, the photoinitiator may be included in an amount of about 0.1% to about 5% by weight of the adhesive film.

In 8.1-7, the adhesive film may further include inorganic particles.

In 9.8, the inorganic particles can include inorganic particles with a refractive index of about 1.5 or greater.

In 10.8-9, the inorganic particles can include zirconia.

11.8-10, the inorganic particles may be included in the adhesive film in an amount of about 5% by weight to about 80% by weight.

In 12.8-11, the inorganic particles may include surface-treated inorganic particles.

In 13.1-12, the photoreactive monomer may be contained in an amount of about 0.1 part by weight to about 50 parts by weight based on 100 parts by weight of the (meth)acrylic binder in the adhesive film. .

In 14.1-13, the aromatic group-containing (meth)acrylic monomer may include a (meth)acrylic monomer represented by the following chemical formula 1:

(In the chemical formula 1,
R ¹ is hydrogen or a methyl group,
R ² is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms,
Ar is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms,
n is an integer from 0 to 3).

In 15.1-14, the photoreactive monomer may include a (meth)acrylate having two or more functionalities.

In 16.1-15, the difunctional or more functional (meth)acrylate is 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate , polyethylene glycol di(meth)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)acryloxyethyl isocyanurate, arylated cyclohexyl di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, dimethyloldicyclopentanedi(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, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene , trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate , trifunctional urethane (meth)acrylate, tris(meth)acryloxyethyl isocyanurate, diglycerin tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate; dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa( It can contain one or more of meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, and hexafunctional urethane(meth)acrylate.

In 17.1-16, the adhesive film may further include a crosslinking agent.

18.1-17, the adhesive film may further include a UV absorber, and the adhesive film may have a light transmittance of about 70% or less at a wavelength of 390 nm or less.

19.1-18, the adhesive film may have a glass transition temperature of about -50°C to about 15°C.

An optical member that is another aspect of the present invention includes the adhesive film of the present invention.

Yet another aspect of the invention is an optical display.

21. The optical display device includes a display panel including one or more functional layers having a refractive index of 1.5 to 2; a first adhesive film; and an optical film; the first adhesive film is the adhesive film of the present invention. including.

In 22.21, a base film may not be included between the optical film and the first adhesive film.

23. In 21-22, the optical film may include a polarizing plate.

24. In 21-23, a second adhesive film may further be included between the polarizing plate and the first adhesive film.

The present invention can provide an adhesive film that has a high refractive index and has variable adhesive strength by UV irradiation.

The present invention can provide a pressure-sensitive adhesive film that has a high refractive index and whose adhesive strength to a base film is significantly reduced by UV irradiation.

The present invention can provide a pressure-sensitive adhesive film that has a high refractive index, but whose adhesive strength to a base film is significantly reduced by UV irradiation, and whose adhesive strength to an adherend is significantly increased.

INDUSTRIAL APPLICABILITY The present invention can provide an adhesive film with excellent optical properties and step-filling properties.

The present invention can provide an adhesive film that provides a thinner thickness effect for an optical display device.

1 is a sectional view of an optical display device according to an embodiment of the present invention. FIG. 1 is a schematic diagram of a manufacturing process of an optical display device according to an embodiment of the present invention. FIG. 1 is a schematic diagram of a process of assembling a display panel and an optical film using a sheet containing a high refractive index adhesive film.

[Best mode for carrying out the invention]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail by way of embodiments with reference to the accompanying drawings so that those skilled in the art can easily carry it out. The present invention can be embodied in various different forms and is not limited to the embodiments described herein.

In the drawings, in order to clearly explain the present invention, parts not related to the description are omitted, and the same names are used for the same or similar components throughout the specification. In the drawings, the length and size of each component are for explaining the present invention, and the present invention is not limited to the length and size of each component shown in the drawings.

In this specification, "upper" and "lower" are defined based on the drawings, and "upper" may be changed to "lower" or "lower" may be changed to "upper" depending on the viewpoint. good.

As used herein, "(meth)acrylic" means acrylic and/or methacryl.

In this specification, "refractive index" is a value measured in the visible light region, for example, at a wavelength of 380 nm to 780 nm.

In this specification, when describing a numerical range, "X to Y" means greater than or equal to X and less than or equal to Y (X≦and≦Y).

The adhesive film of the present invention exhibits a high refractive index of approximately 1.55 or more, and at the same time exhibits variable adhesive strength upon UV irradiation, improving the adhesive strength with the adherend. It can increase the cohesive force of the film and improve its reliability. That is, the adhesive film of the present invention exhibits a high refractive index, and the rate of decrease in adhesive strength with respect to the base film upon UV irradiation is extremely high. Therefore, if the laminate of the adhesive film and base film of the present invention is laminated on an adherend and then UV irradiated, the base film can be easily separated from the adhesive film. This can provide the effect of reducing the thickness of the optical display device. The adhesive film of the present invention exhibits a high refractive index, and while the adhesive strength to the adherend increases by UV irradiation, the adhesive strength to the base film decreases significantly, so that the base film can be easily removed. The reliability after matching with the adhesive can be improved, and the thickness of the optical display device can be reduced. Even when the adhesive film is laminated on an adherend having a high refractive index within the refractive index range, the light extraction efficiency can be increased by minimizing the reflection of light incident on the adhesive film from the adherend.

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

The adhesive film according to this example has an adhesive force change rate of about 90% or more according to the following formula 1:

(In the above formula 1,
A is the adhesive force (unit: gf/inch) when peeling the base film from the adhesive film after laminating the laminate of the adhesive film and the base film on the glass plate;
B is the adhesive force (unit: gf/inch) when a laminate of an adhesive film and a base film is laminated on a glass plate and the base film is peeled from the adhesive film after UV irradiation).

The "glass plate" may be an alkali-free glass plate.

Within the range of the adhesive force change rate, it is easy to manufacture a laminate of an adhesive film and a base film, and when the laminate of an adhesive film and a base film is laminated on an adherend, the adhesive film can be formed by UV irradiation only. The base film can be easily separated from the base film while increasing the adhesion to the adherend, thereby making it possible to reduce the thickness of the optical display device.

Preferably, the rate of change in adhesive strength according to Formula 1 may be about 90% to about 99%, more preferably about 90% to about 98%.

The base film may be a film used when manufacturing an adhesive film. The base film ensures the appearance of the adhesive film when the adhesive composition is applied, but it must be easily removed after the adhesive film is adhered to the adherend.

The base film is a polymer film that has not been subjected to a mold release treatment, and for example, the base film is a polyester film that has not been subjected to a mold release treatment, including a polyethylene terephthalate (PET) film that has not been subjected to a mold release treatment. Alternatively, cellulose ester films including triacetyl cellulose (TAC) films, cycloolefin polymer (COP) films, and acrylic films that have not been subjected to mold release treatment may be included. The "mold release treatment" is a conventional mold release treatment known to those skilled in the art, and may include, for example, one or more of silicone and fluorine treatment. When using a release-treated film as the base film, the adhesive film may have poor appearance.

In one embodiment, the base film may have high UV light transmittance in order to achieve a variable adhesive force effect due to UV irradiation on the adhesive film during the UV irradiation process. For example, the base film may have a light transmittance of about 70% or more, for example, about 70% to about 100%, in the wavelength range of 250 nm to 400 nm, which is the UV irradiation region. Within the above range, the adhesive strength of the adhesive film of the present invention may be reduced by UV irradiation.

UV irradiation is to irradiate a test piece in which a base film, an adhesive film, and a glass plate are sequentially laminated with UV from the base film side, and the UV irradiation is approximately 1000 mJ/cm at a wavelength of 250 nm to 400 nm. ² or less, for example, from about 50 mJ/cm ² to about 800 mJ/cm ² . UV irradiation may be performed using an LED lamp, a high pressure mercury lamp, a metal halide lamp, etc., but is not limited thereto.

Adhesive strength is a value measured at 25°C.

In Formula 1, A is about 1000 gf/inch or more, for example, about 1000 gf/inch, 1100 gf/inch, 1200 gf/inch, 1300 gf/inch, 1400 gf/inch, 1500 gf/inch, 1600 gf/inch, 1700 gf/inch. , 1800gf /inch, 1900gf/inch, 2000gf/inch, 2100gf/inch, 2200gf/inch, 2300gf/inch, 2400gf/inch, 2500gf/inch, 2600gf/inch, 2700gf/inch, 2800gf/ inch, 2900gf/inch, 3000gf/inch , specifically about 1000 gf/inch to about 3000 gf/inch. Since the adhesive film can be fixed to the base film within the above range, a laminate of the adhesive film and the base film can be easily produced, and adhesive strength to the adherend can be easily ensured. A laminate of an adhesive film and a base film can be produced by forming a coating layer by coating one surface of the base film with an adhesive composition, and drying and curing (aging) the coating layer. This will be explained in detail below.

In Formula 1, B is about 100 gf/inch or less, for example, about 10 gf/inch, 20 gf/inch, 30 gf/inch, 40 gf/inch, 50 gf/inch, 60 gf/inch, 70 gf/inch, 80 gf/inch, 90 gf /inch, 100 gf/inch, for example from about 10 gf/inch to about 100 gf/inch. Within the above range, the base film can be easily removed from the adhesive film.

The adhesive film has an adhesive force of about 200 gf/inch or more to the adherend, for example, about 200 gf/inch, 300 gf/inch, 400 gf/inch, 500 gf/inch, 600 gf/inch, 700 gf/inch, 800 gf/inch, 900 gf/inch. inch, 1000gf/inch, 1100gf/inch, 1200gf/inch, 1300gf/inch, 1400gf/inch, 1500gf/inch, 1600gf/inch, 1700gf/inch, 1800gf/inch, 1900gf/i nch, 2000gf/inch, 2100gf/inch, It may be 2200 gf/inch, 2300 gf/inch, 2400 gf/inch, 2500 gf/inch, for example from about 300 gf/inch to about 2500 gf/inch. If the adhesive film is properly fixed to the adherend within the above range, additional adherends can be easily laminated.

In the present specification, the "adherent" may include one or more of inorganic materials including glass, organic materials, and mixtures of organic and inorganic materials. The "adherent" may be in the form of a plate, sheet, film, or display panel (touch panel layer). A pattern may be formed on the "adherent". The "adherent" may have a refractive index of about 1.5 or more.

The adhesive film has a refractive index of about 1.55 or more. Within the above range, when laminated onto an adherend having a high refractive index of about 1.5 or more, reflection of light incident from the adherend can be reduced and light extraction efficiency can be increased. For example, the adhesive film may have a refractive index of about 1.55, 1.6, 1.65, 1.7, 1.75, 1.8, such as about 1.55 to about 1.8 or about 1.6. or about 1.7.

The adhesion of an adhesive film to an adherend can be increased by UV irradiation.

In one specific example, the adhesive film has an adhesive force change rate of about 10% or more, for example, about 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 100%, 200%, 300%, 400%, 500%, 600%, 700%, 800%, 900%, 1000%, about 20% to about 1000%, about 10% to about 500%, and For example, it may be about 20% to about 100%:

(In the above formula 2, C is the adhesive force (unit: gf/inch) of the adhesive film to the glass plate measured by laminating the laminate of the base film and the adhesive film on the glass plate,
D is the adhesive strength (unit: gf/inch) of the adhesive film to the glass plate after laminating the laminate of the base film and the adhesive film on the glass plate and irradiating it with UV.

The "glass plate" may be an alkali-free glass plate.

Within the range of the adhesive force change rate, the adhesive film is more strongly fixed to the adherend, for example, a glass plate, by UV irradiation, thereby facilitating the lamination of additional adherends, and converting the adhesive film into an interlayer adhesive film. It can be easily functioned as

The UV irradiation may be performed at a wavelength of 250 nm to 400 nm and an intensity of about 1000 mJ/cm ² or less, for example, about 50 mJ/cm ² to about 800 mJ/cm ² . UV irradiation may be performed using an LED lamp, a high pressure mercury lamp, a metal halide lamp, etc., but is not limited thereto.

UV irradiation is performed by irradiating a laminate of an adhesive film and a glass plate with UV from the adhesive film side, or by irradiating a laminate of a base film, an adhesive film, and a glass plate with UV from the base film side. Including.

Adhesive strength is a value measured at 25°C.

In the formula 2, C is about 500 gf/inch or more, for example, about 500 gf/inch, 600 gf/inch, 700 gf/inch, 800 gf/inch, 900 gf/inch, 1000 gf/inch, 1100 gf/inch, 1200 gf/inch, 1300 g f /inch, 1400gf/inch, 1500gf/inch, 1600gf/inch, 1700gf/inch, 1800gf/inch, 1900gf/inch, 2000gf/inch, for example, even if it becomes about 500gf/inch to about 2000gf/inch Good. If the adhesive film is properly fixed to the adherend within the above range, additional adherends can be easily laminated.

In the formula 2, D is about 600 gf/inch or more, for example, about 600 gf/inch, 700 gf/inch, 800 gf/inch, 900 gf/inch, 1000 gf/inch, 1100 gf/inch, 1200 gf/inch, 1300 gf/inch, 1400 gf /inch, 1500gf/inch, 1600gf/inch, 1700gf/inch, 1800gf/inch, 1900gf/inch, 2000gf/inch, 2100gf/inch, 2200gf/inch, 2300gf/inch, 2400gf/ inch, 2500gf/inch, 2600gf/inch , 2700 gf/inch, 2800 gf/inch, 2900 gf/inch, 3000 gf/inch, for example, from about 600 gf/inch to about 3000 gf/inch. Within the above range, the adhesive film is more firmly fixed to the adherend, for example, a glass plate, by UV irradiation, thereby facilitating the lamination of additional adherends and making the adhesive film easily function as an interlayer adhesive film. I can do it.

In particular, when the adhesive film of the present invention is irradiated with UV after adhering the laminate of the base film and the adhesive film to an adherend, the adhesive strength to the base film decreases significantly, and at the same time, the adhesive strength to the adherend decreases significantly. By increasing the adhesive strength, fixing the adhesive film to the adherend, and making removal of the base film very easy, adhesion to the adherend and processability can be obtained at the same time.

The adhesive film may have a haze of about 1% or less, for example, about 0% to about 0.5%, in the visible light region, for example, at a wavelength of 550 nm. By transmitting the light incident from the adherend within the above range, the light extraction efficiency can be increased.

The adhesive film may have a thickness of about 25 μm or less, such as greater than about 0 μm and less than about 25 μm, from about 1 μm to about 25 μm. Within the above range, the adhesive film can be used in an optical display device.

The adhesive film has a glass transition temperature of about -50°C to about 15°C, for example, about -50°C, -45°C, -40°C, -35°C, -30°C, -25°C, -20°C, -15°C. °C, -10 °C, -5 °C, 0 °C, 5 °C, 10 °C, 15 °C, specifically about -40 °C to about 10 °C, more specifically about -30 °C to about 5 °C. You can. Within the above range, the effect of providing excellent wettability to the adherend and excellent step-filling properties can be achieved.

The adhesive film contains a (meth)acrylic binder, a photoreactive monomer, and a photoinitiator.

The (meth)acrylic binder contains an aromatic group and a hydroxyl group, and can increase the adhesive strength and refractive index of the adhesive film.

The (meth)acrylic binder has a weight average molecular weight of about 200,000 to about 3 million, for example, 200,000, 300,000, 400,000, 500,000, 600,000, 700,000, 800,000, 900,000, 1 million, 110 million, 1.2 million, 1.3 million, 1.4 million, 1.5 million, 1.6 million, 1.7 million, 1.8 million, 1.9 million, 2 million, 2.1 million, 2.2 million, 2.3 million, 2.4 million, 2.5 million, 2.6 million, 2.7 million, It may be 2.8 million, 2.9 million, 3 million, specifically about 400,000 to about 2 million. Within the above range, the reliability of the adhesive film can be stabilized.

The (meth)acrylic binder includes a (meth)acrylic copolymer of a monomer mixture containing an aromatic group-containing (meth)acrylic monomer and a hydroxyl group-containing (meth)acrylic monomer. Can be done.

The aromatic group-containing (meth)acrylic monomer can increase the refractive index of the adhesive film. The aromatic group-containing (meth)acrylic monomer may include a (meth)acrylate having one or more aromatic groups, but preferably one type of (meth)acrylate having two or more aromatic groups. The above can be included. Including two or more aromatic groups in the aromatic group-containing (meth)acrylate can help the adhesive film ensure a high refractive index. Moreover, by containing two or more aromatic groups in the aromatic-containing (meth)acrylate, the dispersibility of the inorganic particles can be improved when the inorganic particles described in detail below are included.

In one embodiment, the aromatic group-containing (meth)acrylic monomer is a monomer having a homopolymer refractive index of about 1.55 or more, for example, about 1.55 to about 1.80. , for example, a (meth)acrylic monomer of the following chemical formula 1:

(In the chemical formula 1,
R ¹ is hydrogen or a methyl group,
R ² is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms,
Ar is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms,
n is an integer from 0 to 3).

Preferably, the aromatic group-containing (meth)acrylic monomer may include a (meth)acrylic monomer having two or more substituted or unsubstituted aromatic groups. A (meth)acrylic monomer having two or more substituted or unsubstituted aromatic groups can easily ensure the refractive index of the adhesive film when combined with the above-mentioned inorganic particles. The aromatic group may be a single ring or a heterocycle.

Preferably, in the chemical formula 1, Ar may be substituted with an aryl group having 6 to 10 carbon atoms or an aryloxy group having 6 to 10 carbon atoms.

Preferably, in the chemical formula 1, R ² is a hydroxyl group, an amino group, an alkyl group having 1 to 20 carbon atoms, an aryl group having 6 to 20 carbon atoms, an arylalkyl group having 7 to 10 carbon atoms, halogen, or a C 3 alkyl group. It may be substituted with 1 to 10 cycloalkyl groups, cyano groups, thiol groups, etc.

In one specific example, the aromatic group-containing (meth)acrylic monomer is a monomer of Chemical Formula 1 in which Ar is substituted with an aryl group having 6 to 10 carbon atoms, and It may contain a mixture with a monomer of Formula 1 substituted with 6 to 10 aryloxy groups. In this case, the effects of the present invention can be easily realized.

For example, aromatic group-containing (meth)acrylic monomers include phenoxybenzyl (meth)acrylate, phenylphenoxyethyl (meth)acrylate, naphthyl (meth)acrylate, biphenylmethyl (meth)acrylate, and biphenylyl (meth)acrylate. One or more of these, preferably two or more, can be included.

The aromatic group-containing (meth)acrylic monomer is about 30% to about 95% by weight, for example about 30% by weight, 35% by weight of the monomer mixture for the (meth)acrylic copolymer. Weight%, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, 90% by weight, 95% by weight , specifically about 40% to about 90% by weight, more specifically about 50% to about 90% by weight. Within the above range, it can help increase the refractive index of the adhesive film.

The hydroxyl group-containing (meth)acrylic monomer can provide the adhesive strength of the adhesive film. The hydroxyl group-containing (meth)acrylic monomer can include one or more types of (meth)acrylates having 1 to 10 carbon atoms and containing one or more hydroxyl groups. For example, hydroxyl group-containing (meth)acrylic monomers include 2-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, It may contain one or more of 3-hydroxypropyl (meth)acrylate and 6-hydroxyhexyl (meth)acrylate, but is not limited thereto.

The hydroxyl group-containing (meth)acrylic monomer is about 5% to about 70% by weight of the monomer mixture for the (meth)acrylic copolymer, for example, about 5% by weight, 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, specific may be present in an amount of about 5% to about 30% by weight, more specifically about 10% to about 30% by weight. Within the above range, the stability of the adhesive film under high temperature and/or high humidity conditions can be ensured, and the adhesive strength can be increased.

The monomer mixture may further include one or more of a (meth)acrylic monomer having an amide group and a (meth)acrylic monomer having an alkyl group.

A (meth)acrylic monomer having an amide group is advantageous for particle dispersibility in an adhesive film, and can provide a function of improving the haze of the film. (Meth)acrylic monomers having an amide group include (meth)acrylamide, octadecyl (meth)acrylamide, isopropyl (meth)acrylamide, aminopropyl (meth)acrylamide, diethylaminopropyl (meth)acrylamide, and dimethylaminopropyl (meth)acrylamide. ) acrylamide, and N,N-diethyl(meth)acrylamide.

The (meth)acrylic monomer having an amide group is about 0% to about 20% by weight of the monomer mixture, for example about 0%, 0.1%, 0.5%, 1% by weight. Weight%, 2% by weight, 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 11% by weight, 12% by weight, 13% by weight , 14% by weight, 15% by weight, 16% by weight, 17% by weight, 18% by weight, 19% by weight, 20% by weight, specifically about 0% by weight to about 10% by weight, about 0.1% by weight to It may be included at about 10% by weight. Within the above range, the effect of increasing the adhesive strength of the adhesive film can be provided.

The (meth)acrylic monomer having an alkyl group is a (meth)acrylic monomer having a linear or branched alkyl group having 1 to 20 carbon atoms (preferably 2 to 20 carbon atoms). Acid esters may be included. (Meth)acrylic acid esters having an alkyl group having 1 to 20 carbon atoms include methyl (meth)acrylate, ethyl (meth)acrylate, propyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl ( meth) acrylate, pentyl (meth) acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, heptyl (meth) acrylate, octyl (meth) acrylate, iso-octyl (meth) acrylate, nonyl (meth) acrylate, It may contain one or more of decyl (meth)acrylate and dodecyl (meth)acrylate, but is not limited thereto.

The (meth)acrylic monomer having an alkyl group is about 0% to about 40% by weight of the monomer mixture, for example, about 0%, 0.1%, 1%, 2% by weight. , 3% by weight, 4% by weight, 5% by weight, 6% by weight, 7% by weight, 8% by weight, 9% by weight, 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35 % by weight, 40% by weight, specifically about 0% by weight to about 30% by weight, about 0.1% by weight to about 10% by weight. Within the above range, the effect of increasing the adhesive strength of the adhesive film can be provided.

The photoreactive monomer is photocured by UV irradiation and a photoinitiator in a state where the cured product of the (meth)acrylic binder provides adhesive strength, thereby reducing the adhesive strength of the adhesive film to the base film, Adhesion to adherends, such as glass plates, can be increased.

The photoreactive monomer can include a difunctional or higher-functional (meth)acrylate having two or more UV-curable photoreactive functional groups.

When the adhesive film is irradiated with UV, the (meth)acrylate having two or more functionalities increases the degree of crosslinking of the adhesive film by undergoing a photocuring reaction with a photoinitiator, and reduces the adhesive force with the base film. Adhesive strength to adhesives can be increased. Since the difunctional or more functional (meth)acrylate has a faster photocuring reaction rate than the monofunctional (meth)acrylate even if the content thereof is small, the adhesive force can be easily reduced.

The (meth)acrylate having two or more functionalities can specifically include a difunctional to 10-functional (meth)acrylate, more specifically a di-functional to hexafunctional (meth)acrylate. For example, (meth)acrylates having two or more functionalities include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and polyethylene glycol di(meth)acrylate. ) 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)acryloxyethyl isocyanate Nurate, arylated cyclohexyl di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, dimethyloldicyclopentane di(meth)acrylate, ethylene oxide modified hexahydrophthalic acid di(meth)acrylate, tricyclodecane dimethanol ( Difunctional acrylates such as meth)acrylate, neopentyl glycol-modified trimethylpropane di(meth)acrylate, adamantane di(meth)acrylate or 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene ; Trimethylolpropane tri(meth)acrylate, dipentaerythritol tri(meth)acrylate, propionic acid modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate , trifunctional acrylates such as trifunctional urethane (meth)acrylate or tris(meth)acryloxyethyl isocyanurate; tetrafunctional acrylates such as diglycerin tetra(meth)acrylate or pentaerythritol tetra(meth)acrylate; dipenta Pentafunctional acrylates such as erythritol penta(meth)acrylate; and dipentaerythritol hexa(meth)acrylate, caprolactone-modified dipentaerythritol hexa(meth)acrylate, urethane(meth)acrylate (ex. isocyanate monomer and trimethylolpropane) One or more types of hexafunctional acrylates such as (reactants of tri(meth)acrylate) can be mentioned, but the invention is not limited thereto.

The photoreactive monomer is about 1% to about 50% by weight of the adhesive film, for example, about 1%, 2%, 3%, 4%, 5%, 6%, 7% by weight. , 8% by weight, 9% by weight, 10% by weight, 15% by weight, 20% by weight, 25% by weight, 30% by weight, 35% by weight, 40% by weight, 45% by weight, 50% by weight, specifically about It may be included from 1% to about 30% by weight, more specifically from about 1% to about 10% by weight. Within the above range, the adhesive strength of the adhesive film is not affected before UV irradiation, and the adhesive strength of the adhesive film can be reduced after UV irradiation.

Photoinitiators can include photoradical initiators that generate photoradicals by light, such as UV.

In one embodiment, the photoinitiator can include a long wavelength absorbing photoinitiator with a maximum absorption wavelength of about 250 nm or more, such as from about 300 nm to about 400 nm. When UV is irradiated through the base film in the range of the maximum absorption wavelength, the adhesive force can be significantly reduced by UV irradiation, and the effects of the present invention can be obtained even with a small intensity of UV irradiation. can. The "maximum absorption wavelength" refers to the wavelength at which the maximum absorbance occurs when absorbance is measured after dissolving the photoinitiator in cyclohexane at a concentration of 1 mg/ml.

As the photoinitiator, specifically, a phosphine oxide type, benzoin type, hydroxyketone type, or aminoketone type photoinitiator can be used. For example, photoinitiators include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin n-butyl ether, benzoin isobutyl ether, 2,2-dimethoxy-2-phenylacetophenone, 2,2'-diethoxyacetophenone. , 2,2'-dibutoxyacetophenone, 2-hydroxy-2-methylpropiophenone, pt-butyltrichloroacetophenone, pt-butyldichloroacetophenone, 4-chloroacetophenone, 2,2'-dichloro-4 - Acetophenone compounds such as phenoxyacetophenone, dimethylaminoacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-2-phenylacetophenone, 2-hydroxy-2-methyl-1-phenylpropan-1one, 2-Benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 1-hydroxycyclohexylphenylketone, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholino- Propan-1-one, 4-(2-hydroxyethoxy)phenyl-2-(hydroxy-2-propyl)ketone, benzophenone, p-phenylbenzophenone, 4,4-diethylaminobenzophenone, dichlorobenzophenone, 2-methylanthraquinone, 2 -Ethylanthraquinone, 2-t-butylanthraquinone, 2-aminoanthraquinone, 2-methylthioxanthone, 2-ethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, benzyldimethyl Ketal, acetophenone dimethyl ketal, p-dimethylaminobenzoic acid ester, oligo[2-hydroxy-2-methyl-1-[4-(1-methylvinyl)phenyl]propanone] and 2,4,6-trimethylbenzoyl-diphenyl - phosphine oxide, etc., but are not limited to these.

The photoinitiator may be present in an amount of about 0.01% to about 5% by weight of the adhesive film, such as about 0.01%, 0.05%, 0.1%, 0.2%, 0. 3% by weight, 0.4% by weight, 0.5% by weight, 0.6% by weight, 0.7% by weight, 0.8% by weight, 0.9% by weight, 1.0% by weight, 1.5% by weight %, 2% by weight, 2.5% by weight, 3% by weight, 3.5% by weight, 4% by weight, 4.5% by weight, 5% by weight, specifically about 0.05% by weight to about 4% by weight %, more specifically from about 0.1% to about 1% by weight. Within the above range, the adhesive strength of the adhesive film is not affected before UV irradiation, the adhesive strength of the adhesive film can be reduced after UV irradiation, and the optical transparency of the adhesive film is improved by the remaining amount of photoinitiator. can be prevented from decreasing.

The adhesive film can further include a crosslinking agent.

The crosslinking agent can form a matrix of the adhesive film by thermosetting the (meth)acrylic binder, thereby increasing the reliability of the adhesive film.

The crosslinking agent can include conventional thermosetting agents used to thermoset (meth)acrylic binders. For example, the crosslinking agent may include one or more of an isocyanate crosslinking agent, a carbodiimide crosslinking agent, an aziridine crosslinking agent, and an epoxy crosslinking agent. Preferably, an isocyanate-based crosslinking agent can be included as a crosslinking agent.

The isocyanate crosslinking agent may include a bifunctional or more functional, for example, a bifunctional to hexafunctional isocyanate crosslinking agent. In one specific example, the isocyanate-based crosslinking agent includes xylene diisocyanate (XDI) including m-xylene diisocyanate and the like, methylene bis(phenylisocyanate) (MDI) including 4,4'-methylene bis(phenylisocyanate), naphthalene diisocyanate, It can contain one or more of diisocyanate, hexamethylene diisocyanate, and isophorone diisocyanate, or an adduct thereof, or an isocyanurate thereof. For example, the adduct or isocyanurate includes a trimethylolpropane adduct of tolylene diisocyanate, a trimethylolpropane adduct of hexamethylene diisocyanate, a trimethylolpropane adduct of isophorone diisocyanate, a trimethylolpropane adduct of xylene diisocyanate, It may be an isocyanurate of tolylene diisocyanate, an isocyanurate of hexamethylene diisocyanate, and an isocyanurate of isophorone diisocyanate.

The crosslinking agent is about 0.001 parts by weight to about 5 parts by weight, for example, about 0.001 parts by weight, 0.005 parts by weight, 0.01 parts by weight, 0 parts by weight, based on 100 parts by weight of the (meth)acrylic binder. .05 parts by weight, 0.1 parts by weight, 0.5 parts by weight, 1 part by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight , 4.5 parts by weight, 5 parts by weight, specifically about 0.005 parts by weight to about 3 parts by weight. Within the above range, the matrix of the adhesive film can be well formed and adhesive strength can be exhibited.

The adhesive film can further include a silane coupling agent.

The silane coupling agent can further increase the peeling force of the adhesive film to the adherend. Silane coupling agents can include the conventional types known to those skilled in the art. For example, the silane coupling agent is a silicon compound having an epoxy structure such as 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, and 2-(3,4-epoxycyclohexyl)ethyltrimethoxylane. ; Polymerizable unsaturated group-containing silicon compounds such as vinyltrimethoxysilane, vinyltriethoxysilane, (meth)acryloxypropyltrimethoxysilane; 3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3- Contains one or more selected from the group consisting of amino group-containing silicon compounds such as aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane, and 3-chloropropyltrimethoxysilane. but are not limited to these.

The silane coupling agent may be included in the adhesive film in an amount of about 0.001% to about 2% by weight, specifically about 0.001% to about 1% by weight. Within the above range, other physical properties of the adhesive film are not affected, and the adhesive strength of the adhesive film to the adherend can be increased.

The adhesive film can further include inorganic particles.

Inorganic particles can be included in adhesive films to help reduce adhesive strength due to UV irradiation.

The shape of the inorganic particles is not limited, but may be, for example, spherical, amorphous, plate-like, or granular. The inorganic particles have an average particle diameter (D50) smaller than the thickness of the adhesive film, and as nanoparticles, about 1 nm to about 200 nm, for example, about 1 nm, 5 nm, 10 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm. , 90nm, 100nm, 110nm, 120nm, 130nm, 140nm, 150nm, 160nm, 170nm, 180nm, 190nm, 200nm, for example about 5nm to about 150nm. Since the inorganic particles can be included in the adhesive film within the above range, the effects of the adhesive film can be realized. The "average particle size (D50)" may be measured by a conventional method known to those skilled in the art. For example, the average particle size (D50) refers to a particle size that corresponds to 50% of inorganic particles in cumulative weight analysis using a particle size analyzer.

The inorganic particles can include non-surface-treated inorganic particles, but by including surface-treated inorganic particles, the inorganic particles can be well dispersed in the adhesive composition, and as a result, the adhesive film haze increase can be prevented. Surface treatment may be carried out by conventional methods known to those skilled in the art. For example, the inorganic particles may be surface-treated with a (meth)acrylic compound or the like.

In one embodiment, the inorganic particles can include inorganic particles with a refractive index of about 1.5 or greater, such as from about 1.5 to about 1.8. By helping to increase the refractive index of the adhesive film within the above range, the light extraction efficiency can be increased by reducing the reflection of light incident from the adherend when it is laminated onto the adherend. For example, the inorganic particles can include one or more of zirconia, titania, zinc oxide, and aluminum oxide, preferably zirconia.

The inorganic particles are about 0% to about 80% by weight of the adhesive film, for example, about 0%, 5%, 10%, 15%, 20%, 25%, 30%, 35% by weight. Weight%, 40% by weight, 45% by weight, 50% by weight, 55% by weight, 60% by weight, 65% by weight, 70% by weight, 75% by weight, 80% by weight, 85% by weight, 90% by weight, specifically may be present in an amount of about 5% to about 80% by weight, more specifically about 5% to about 70% by weight, most specifically about 25% to about 70% by weight. Within the above range, the refractive index of the adhesive film can be increased without affecting the adhesive strength of the adhesive film before and after UV irradiation.

The adhesive film can further include a UV absorber.

By absorbing UV incident from the outside, the UV absorber can prevent damage to the light emitting elements in the light emitting display panel laminated on the lower surface of the adherend and extend the life of the light emitting elements. . In one embodiment, the adhesive film containing the UV absorber may have a light transmittance of about 70% or less, such as about 30% to about 70%, at a wavelength of 390 nm or less, for example, from 380 nm to 390 nm. Within the above range, damage to the light emitting element can be prevented.

In one embodiment, the UV absorber may have a maximum absorption wavelength of about 370 nm to about 410 nm, specifically about 370 nm to about 400 nm. Within the above range, damage to the light emitting element can be prevented, and the decrease in adhesive strength of the adhesive film due to UV irradiation may not be affected.

In one specific example, an indole UV absorber or the like can be used as the UV absorber, but is not limited thereto.

The UV absorber may be included in the adhesive film in an amount of about 0.01% to about 2% by weight, specifically about 0.01% to about 1% by weight. Within the above range, the damage prevention function of the light emitting device can be realized without affecting the decrease in adhesive force of the adhesive film due to UV irradiation.

The adhesive film can further contain additives.

Additives include antistatic agents, surfactants, curing accelerators, ionic liquids, lithium salts, softeners, molecular weight regulators, antioxidants, anti-aging agents, stabilizers, tackifier resins, modified resins (polyols, etc.). resins, phenolic resins, acrylic resins, polyester resins, polyolefin resins, epoxy resins, epoxidized polybutadiene resins, etc.), leveling agents, antifoaming agents, plasticizers, dyes, pigments (coloring pigments, extender pigments, etc.), processing agents, fluorescence It may contain conventional additives such as, but not limited to, brighteners, dispersants, heat stabilizers, light stabilizers, flocculants, lubricants, etc.

The additive may be included in the adhesive film in an amount of about 10% by weight or less, specifically about 0.01% to about 10% by weight, specifically about 0.01% to about 1% by weight. good. Within the above range, the adhesive strength and reliability of the adhesive film are not affected, and the effect of the additive can be produced.

Adhesive films are manufactured by forming a coating layer by coating one surface of a base film with the adhesive composition described in detail below, and drying and curing (or thermosetting or aging) the coating layer. obtain. In order to prevent foreign matter from adhering to the adhesive film after or before the coating layer is cured, a release film may be further applied to one side of the coating layer or the adhesive film. The base film is as described above. The release film is a polymer film that has been subjected to a release treatment (eg, silicone treatment or fluorine treatment), and may include a polyester film including a polyethylene terephthalate film. In one specific example, the adhesive film may include a cured product (eg, thermoset) of a (meth)acrylic binder and a crosslinking agent; and a photoreactive monomer. The adhesive film may further include one or more of inorganic particles, a photoinitiator, a silane coupling agent, a UV absorber, and an additive.

Drying may include, but is not limited to, treating the coating layer at about 100° C. to about 150° C. for about 0.5 minutes to about 5 minutes. Curing (or heat curing or aging) may include, but is not limited to, treating the dried coating layer at about 40° C. to about 80° C. for about 0.5 days to about 3 days.

Hereinafter, a pressure-sensitive adhesive composition according to an example of the present invention will be described.

The adhesive composition includes a (meth)acrylic binder, a photoreactive monomer, and a photoinitiator. The adhesive composition may further include one or more of a crosslinking agent and inorganic particles. The adhesive composition may further include one or more of a silane coupling agent and a UV absorber. The adhesive composition can further contain additives.

The (meth)acrylic binder, photoreactive monomer, photoinitiator, crosslinking agent, inorganic particles, silane coupling agent, UV absorber, and additives are substantially the same as those described above. Here, descriptions of the (meth)acrylic binder, crosslinking agent, photoreactive monomer, photoinitiator, inorganic particles, silane coupling agent, UV absorber, and additives will be omitted.

The photoreactive monomer is about 0.1 parts by weight to about 50 parts by weight, for example, 0.1 parts by weight, based on 100 parts by weight of the total of the (meth)acrylic binder or the (meth)acrylic binder and inorganic particles. 0.5 parts by weight, 1 part by weight, 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, Specifically, it may be included in an amount of about 1 part by weight to about 30 parts by weight, about 1 part to about 20 parts by weight, or about 5 parts by weight to about 15 parts by weight. Within the above range, the effect of reducing the adhesive force to the base film after UV irradiation can be achieved.

The photoinitiator is about 0.001 parts by weight to about 5 parts by weight, for example, about 0.001 parts by weight, based on 100 parts by weight of the (meth)acrylic binder or (meth)acrylic binder and inorganic particles. 0.05 parts by weight, 0.1 parts by weight, 0.5 parts by weight, 1 parts by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 parts by weight, 3.5 parts by weight, 4 parts by weight part, 4.5 parts by weight, 5 parts by weight, specifically about 0.1 part by weight to about 1 part by weight. Within the above range, the effect of reducing the adhesive force to the base film after UV irradiation can be achieved.

The crosslinking agent is about 0.001 parts by weight to about 5 parts by weight, for example, about 0.001 parts by weight, 0. .005 parts by weight, 0.01 parts by weight, 0.05 parts by weight, 0.1 parts by weight, 0.5 parts by weight, 1 parts by weight, 1.5 parts by weight, 2 parts by weight, 2.5 parts by weight, 3 Parts by weight, 3.5 parts by weight, 4 parts by weight, 4.5 parts by weight, 5 parts by weight, specifically about 0.005 parts by weight to about 3 parts by weight. Within the above range, the effect of increasing the cohesive force of the adhesive film can be achieved.

The (meth)acrylic binder is about 30 parts by weight to about 95 parts by weight, for example, about 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, out of 100 parts by weight of the (meth)acrylic binder and inorganic particles. parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, 75 parts by weight, 80 parts by weight, 85 parts by weight, 90 parts by weight, 95 parts by weight, specifically about 40 parts by weight parts to about 95 parts by weight. Within the above range, the effect can be achieved that it can serve as a matrix in which inorganic particles can be well dispersed.

The inorganic particles are about 5 parts by weight to about 70 parts by weight, for example, about 5 parts by weight, 10 parts by weight, 15 parts by weight, 20 parts by weight, 25 parts by weight out of 100 parts by weight of the (meth)acrylic binder and inorganic particles. Parts by weight, 30 parts by weight, 35 parts by weight, 40 parts by weight, 45 parts by weight, 50 parts by weight, 55 parts by weight, 60 parts by weight, 65 parts by weight, 70 parts by weight, specifically about 5 parts by weight to about 60 parts by weight May be included in parts by weight. Within the above range, the effect of increasing the refractive index of the adhesive film can be achieved.

The adhesive composition can further contain a solvent. The solvent can enhance the applicability of the adhesive composition and help ensure that the adhesive composition is applied uniformly. The solvent can include one or more organic solvents commonly known to those skilled in the art.

An optical member according to an embodiment of the present invention will be described below.

The optical member according to this example includes the adhesive film of the present invention.

In one specific example, the optical member includes an adhesive film and an adherend laminated on at least one surface of the adhesive film. In one embodiment, the adherend can have a high refractive index compared to the adhesive film. A light emitting device panel is located on the lower surface of the adherend, and light incident from the light emitting device panel may be sequentially transmitted through the adherend and the adhesive film. The adhesive film of the present invention can improve light extraction efficiency by reducing the difference in refractive index with the adherend compared to conventional adhesive films. For example, the adherend may have a refractive index of about 1.5 or greater, specifically about 1.5 to about 2.0, more specifically about 1.7 to about 2.0.

The optical display device of the present invention includes the adhesive film of the present invention or the optical member of the present invention. The optical display device may include a light emitting device display device, including an organic light emitting device display device, a liquid crystal display device, and the like.

The optical display device includes a display panel including one or more functional layers having a refractive index of about 1.5 to about 2, a first adhesive film, and an optical film, where the first adhesive film is the adhesive film of the present invention. including.

In one embodiment, an optical display device may include a display panel including a functional layer having a refractive index of about 1.5 to about 2, an adhesive film, and an optical film, which are sequentially laminated.

The display panel is a portion that includes light emitting elements and emits light to drive a display device. The light emitting devices of the display panel may include, but are not limited to, OLEDs, QDs, QD-OLEDs, and the like.

The functional layer has a refractive index of about 1.5 to about 2 and can provide additional functionality when driving the optical display device or display panel. The functional layer may be composed of a single layer or two or more layers.

In one embodiment, the functional layer can include a touch screen panel, a passivation layer, and the like. A touch screen panel recognizes the position of a touch on the screen of an optical display device with a hand or a pen, thereby allowing the display device to receive information input from the screen so as to perform specific processing. The touch screen panel may be formed of a metal material such as aluminum or titanium. The passivation layer is an insulating layer, and may be composed of multiple layers made of one or more of an organic material and an inorganic material.

Optical films include window films, windows, polarizing plates, color filters, retardation films, elliptical polarizing films, reflective polarizing films, antireflection films, compensation films, brightness enhancement films, alignment films, light diffusion films, glass shatter prevention films, etc. can include. Preferably, the optical film may be a polarizing plate including a polarizer and a protective layer (eg, a protective film or a protective coating layer) formed on at least one surface of the polarizer.

The above-mentioned base film may not be included between the optical film and the first adhesive film. This is because the base film is easily removed from the adhesive film by UV irradiation. This will be explained in detail with reference to FIG. 2 below.

A second adhesive film may further be included between the optical film and the first adhesive film. The type of the second adhesive film is not limited as long as it can provide high adhesive strength to the optical film. For example, the second adhesive film may be a vacuum adhesive (PSA).

FIG. 1 is a sectional view of an optical display device according to an embodiment of the present invention.

Referring to FIG. 1, the optical display device may include a display panel 110, a touch screen panel 120, an adhesive film 140, and an optical film 150, which are sequentially stacked on the top surface of the display panel 110. A passivation layer 130 is formed in a pattern on the upper surface of the touch screen panel 120 . The display panel, touch screen panel, adhesive film, optical film, and passivation layer are each as described above.

FIG. 2 is a schematic diagram of a manufacturing process of an optical display device according to an embodiment of the present invention.

Referring to FIG. 2, in (I), a sheet composed of a high refractive index adhesive film 20 and a base film 30 is laminated on a display panel 10 including a high refractive index functional layer. In (II), after irradiating UV from the base film 30 side, the base film 30 is peeled off. In (III), an adherend 40 including an optical film or the like is laminated on the adhesive film 20 having a high refractive index.

Although not shown in FIG. 2, an additional adhesive film may be further included between the high refractive index adhesive film 20 and the adherend 40.

[Form for carrying out the invention]
Hereinafter, the structure and operation of the present invention will be explained 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 way.

Example 1
90 parts by weight of a mixture of 2-phenoxybenzyl acrylate (PBA-001, Hanong Chemical) and 2-phenylphenoxyethyl acrylate (PP-011, Hanong Chemical) and 10 parts by weight of 4-hydroxybutyl acrylate were placed in a reactor. A UV initiator is added to 100 parts by weight of the monomer mixture containing aromatic groups (2-phenoxybenzyl group and 2-phenylphenoxy group) and hydroxyl group-containing (meth)acrylic binder A by polymerizing while purging with nitrogen. (Weight average molecular weight: 1 million) was produced.

A zirconia-containing sol (ZP-158, Nippon Shokubai Co., Ltd., average particle size (D50) of zirconia: 15 nm, zirconia was surface-treated. Refractive index of zirconia: 1.75 to the (meth)acrylic binder A produced above. ) was added to adjust the amount of the (meth)acrylic binder prepared above to 70 parts by weight and the amount of zirconia to 30 parts by weight based on the solid content.

Thereafter, based on the solid content, a crosslinking agent (L-45, Soken Kagaku Co., Ltd., isocyanate crosslinking agent ) 0.01 parts by weight, 5 parts by weight of dipentaerythritol hexaacrylate as a photoreactive monomer, and 0.5 parts by weight of a phosphorus initiator (TPO) as a photoinitiator and defoamed to form an adhesive composition. manufactured something.

The produced adhesive composition was applied to one side of a polyethylene terephthalate film (TU73A, SKC, thickness: 75 μm, not subjected to release treatment) as a base film at a thickness of 20 μm to 25 μm, and heated at 120° C. for 2 minutes. After drying and curing (aging) at 50° C. for 2 days, a polyethylene terephthalate film (R56, Toray Industries, Ltd., thickness: 38 μm, to be subjected to mold release treatment), which is a release film, was covered, and a base film, A laminate of an adhesive film (thickness: 20 μm) and a release film was produced.

Examples 2 to 6
The same method as in Example 1 was carried out, except that the content of each component in Example 1 was changed as shown in Table 1 below (unit: parts by weight), and the base film, adhesive film, and mold release were prepared. A film laminate was produced. The UV absorber used in Example 5 was UV-3912 (indole type, Orient Chemical Industry Co., Ltd.).

Comparative example 1 to comparative example 2
A laminate of a base film, an adhesive film, and a release film was produced by carrying out the same method as in Example 1, except that the content of each component in Example 1 was changed as shown in Table 1 below. did.

Comparative example 3
Add a UV initiator to 100 parts by weight of a monomer mixture containing 50 parts by weight of 2-ethylhexyl acrylate, 30 parts by weight of butyl acrylate, and 20 parts by weight of 4-hydroxybutyl acrylate in a reactor, and polymerize while purging with nitrogen. (Meth)acrylic binder B (weight average molecular weight: 1 million) was produced.

Thereafter, the same method as in Example 1 was carried out except that the content of each component in Example 1 was changed as shown in Table 1 below, and a laminate of the base film, adhesive film, and release film was obtained. was manufactured.

The physical properties shown in Table 2 below were evaluated for the laminates manufactured in Examples and Comparative Examples, and the results are shown in Table 2 below.

(1) Formula 1 (unit %): The release film was peeled off from the base film/adhesive film/release film laminate (width x length, 2.5 cm x 10 cm) produced in the examples and comparative examples. Thereafter, a test piece was manufactured by combining the adhesive film/substrate film laminate onto a non-alkali glass plate (width x length, 3 cm x 10 cm) using the adhesive film as an intermediary. The manufactured test piece was fixed to the TA Instrument (Instrument), which is an adhesion measuring device, and the adhesive force ( A in Formula 1 (unit: gf/inch) is measured.

After peeling off the release film from the base film/adhesive film/release film laminate (width x length, 2.5 cm x 10 cm) manufactured in Examples and Comparative Examples, a non-alkali glass plate (width x length) was peeled off. , 3 cm x 10 cm) using the adhesive film as a medium, and then irradiated with UV at 500 mJ/cm ² using a metal halide lamp on the base film side to prepare a test piece. The manufactured test piece was fixed to a TA instrument, which is an adhesive force measuring device, and the adhesive force when peeling the base film from the adhesive film at 25°C, a peeling speed of 300 mm/min, and a peeling angle of 180° (in Formula 1) B, unit: gf/inch) is measured. Calculate the value of Equation 1 above.

(2) Formula 2 (unit: %): Peeling the release film from the base film/adhesive film/release film laminate (width x length, 2.5 cm x 10 cm) manufactured in Examples and Comparative Examples Thereafter, a test piece was manufactured by combining the adhesive film/substrate film laminate onto a non-alkali glass plate (width x length, 3 cm x 10 cm) using the adhesive film as an intermediary. The manufactured test piece was fixed to a TA instrument, which is an adhesive force measuring device, and the adhesive force (Formula 2 C, unit: gf/inch) is measured.

After peeling off the release film from the base film/adhesive film/release film laminate (width x length, 2.5 cm x 10 cm) manufactured in Examples and Comparative Examples, a non-alkali glass plate (width x length) was peeled off. , 3 cm x 10 cm) using the adhesive film as a medium, and irradiated with UV at 500 mJ/cm ² using a metal halide lamp on the base film side to prepare a test piece. The manufactured test piece was fixed to a TA instrument, which is an adhesive force measuring device, and the adhesive force (Formula 2 D, unit: gf/inch) is measured. Calculate the value of Equation 2 above.

(3) Refractive index: The base film and the release film were separated from the laminate, and the adhesive film alone was measured in the visible light region using a Prism coupler, which is a refractive index measuring device.

(4) Haze (unit: %): After separating the base film and release film from the laminate and placing the obtained adhesive film on an alkali-free glass plate, the haze measurement device NDH-9000 was used to measure the visible Measured in the light field.

(5) Step filling ability: A pattern (width x length x height, 25 μm x 25 μm x 2 μm) was made on a glass plate using photoresist. The release film was removed from the laminates prepared in Examples and Comparative Examples, and the laminates were placed on the prepared pattern using an adhesive film, and then autoclaved (50° C., 3.5 bar, 1000 seconds). It was confirmed using an optical microscope whether or not there were air bubbles in the stepped portions of the pattern. If no air bubbles were generated, it was evaluated as ○, and if even a few air bubbles were generated, it was evaluated as x.

(6) Light transmittance (unit: %): After separating the base film and release film from the laminate and placing the obtained adhesive film on a non-alkali glass plate, Light transmittance at a wavelength of 390 nm was measured using a spectrometer.

(7) Tg of adhesive film (unit: °C): The base film and release film were separated from the laminates produced in Examples and Comparative Examples, and the resulting adhesive film was measured by DSC.

As shown in Table 2, the adhesive strength of the adhesive film of the present invention to the base film is significantly reduced by UV irradiation, which is 90% or more according to Formula 1 of the present application, and the adhesive strength to the base film is decreased by UV irradiation. It has excellent processability, high refractive index, excellent optical properties, and step-filling properties, as the adhesion to the adherend is significantly increased.

On the other hand, the adhesive film of the comparative example did not have the effect of the present invention.

Simple variations and modifications of the present invention can be easily effected by those skilled in the art, and all such variations and modifications can be considered to be within the scope of the present invention. .

Claims (24)

An adhesive film comprising a (meth)acrylic binder, a photoreactive monomer, and a photoinitiator,
The adhesive film has an adhesive force change rate of about 90% or more according to the following formula 1, and a refractive index of about 1.55 or more:

(In the above formula 1, A is the adhesive force (unit: gf/inch) when peeling the base film from the adhesive film after laminating the laminate of the adhesive film and the base film on the glass plate,
B is the adhesive force (unit: gf/inch) when a laminate of an adhesive film and a base film is laminated on a glass plate and the base film is peeled from the adhesive film after UV irradiation). The adhesive film according to claim 1, wherein A in the formula 1 is about 1000 gf/inch or more, and B in the formula 1 is about 100 gf/inch or less. The adhesive film according to claim 1, wherein the adhesive film has an adhesive force change rate of about 10% or more according to the following formula 2:

(In the above formula 2, C is the adhesive force (unit: gf/inch) of the adhesive film to the glass plate measured by laminating the laminate of the base film and the adhesive film on the glass plate,
D is the adhesive strength (unit: gf/inch) of the adhesive film to the glass plate after laminating the laminate of the base film and the adhesive film on the glass plate and irradiating it with UV. The adhesive film according to claim 3, wherein C in the formula 2 is about 500 gf/inch or more, and D in the formula 2 is about 600 gf/inch or more. The (meth)acrylic binder is a monomer containing an aromatic group-containing (meth)acrylic monomer, a hydroxyl group-containing (meth)acrylic monomer, and an alkyl group-containing (meth)acrylic monomer. The adhesive film according to claim 1, comprising a (meth)acrylic copolymer mixture. The (meth)acrylic binder includes a (meth)acrylic copolymer of a monomer mixture,
In the monomer mixture, the aromatic group-containing (meth)acrylic monomer is about 30% to about 95% by weight, and the hydroxyl group-containing (meth)acrylic monomer is about 5% to about 30% by weight. The adhesive film according to claim 1, wherein the alkyl group-containing (meth)acrylic monomer is about 0% to about 40% by weight. The adhesive film of claim 1, wherein the photoinitiator is included in an amount of about 0.1% to about 5% by weight of the adhesive film. The adhesive film according to claim 1, wherein the adhesive film further contains inorganic particles. The adhesive film according to claim 8, wherein the inorganic particles include inorganic particles having a refractive index of about 1.5 or more. The adhesive film according to claim 8, wherein the inorganic particles include zirconia. The adhesive film according to claim 8, wherein the inorganic particles are contained in the adhesive film in an amount of about 5% to about 80% by weight. The adhesive film according to claim 8, wherein the inorganic particles include surface-treated inorganic particles. The adhesive film according to claim 1, wherein the photoreactive monomer is contained in an amount of about 0.1 part by weight to about 50 parts by weight based on 100 parts by weight of the (meth)acrylic binder in the adhesive film. The adhesive film according to claim 5, wherein the aromatic group-containing (meth)acrylic monomer includes a (meth)acrylic monomer represented by the following chemical formula 1:

(In the chemical formula 1,
R ¹ is hydrogen or a methyl group,
R ² is a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms or a substituted or unsubstituted alkylene group having 1 to 10 carbon atoms,
Ar is a substituted or unsubstituted aryl group having 6 to 20 carbon atoms or a substituted or unsubstituted heteroaryl group having 3 to 20 carbon atoms,
n is an integer from 0 to 3). The adhesive film according to claim 1, wherein the photoreactive monomer includes a (meth)acrylate having two or more functionalities. The (meth)acrylates having two or more functional groups include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and polyethylene glycol di(meth)acrylate. 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)acryloxyethyl isocyanurate , arylated cyclohexyl di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, dimethyloldicyclopentane di(meth)acrylate, ethylene oxide modified hexahydrophthalic acid di(meth)acrylate, tricyclodecane dimethanol (meth)acrylate, ) acrylate, neopentyl glycol-modified trimethylpropane di(meth)acrylate, adamantane di(meth)acrylate, 9,9-bis[4-(2-acryloyloxyethoxy)phenyl]fluorene, trimethylolpropane tri(meth)acrylate, ) acrylate, dipentaerythritol tri(meth)acrylate, propionic acid modified dipentaerythritol tri(meth)acrylate, pentaerythritol tri(meth)acrylate, propylene oxide modified trimethylolpropane tri(meth)acrylate, trifunctional urethane(meth)acrylate ) acrylate, tris(meth)acryloxyethyl isocyanurate, diglycerin tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate; dipentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate, caprolactone modified di- The adhesive film according to claim 15, containing one or more of pentaerythritol hexa(meth)acrylate and hexafunctional urethane (meth)acrylate. The adhesive film according to claim 1, further comprising a crosslinking agent. The adhesive film further includes a UV absorber,
The adhesive film according to claim 1, wherein the adhesive film has a light transmittance of about 70% or less at a wavelength of 390 nm or less. The adhesive film according to claim 1, wherein the adhesive film has a glass transition temperature of about -50°C to about 15°C. An optical member comprising the adhesive film according to any one of claims 1 to 19. A display panel comprising one or more functional layers having a refractive index of about 1.5 to about 2;
a first adhesive film; and an optical film;
An optical display device, wherein the first adhesive film includes the adhesive film according to any one of claims 1 to 19. The optical display device according to claim 21, wherein a base film is not included between the optical film and the first adhesive film. The optical display device according to claim 21, wherein the optical film includes a polarizing plate. The optical display device according to claim 22, further comprising a second adhesive film between the polarizing plate and the first adhesive film.