KR20200012646A - Optical laminate and display device - Google Patents

Abstract

The present invention relates to an optical laminate and a display device including the optical laminate, wherein the optical laminate includes: a substrate; and a hard coating layer formed on at least one surface of the substrate and including two or more kinds of inorganic particles having an average radius different from that of a binder resin, a domain, formed by allowing second inorganic particles having an average radius of 20 to 35 nm to surround first inorganic particles having an average radius of 10 to 15 nm, is formed on the hard coating layer, and the weight ratio of the first inorganic particles to the second inorganic particle is 1 : 9 to 9 : 1.

Description

Optical laminated body and display device {OPTICAL LAMINATE AND DISPLAY DEVICE}

The present invention relates to an optical laminate and a display device.

Recently, with the development of mobile devices such as smart phones and tablet PCs, thinning and slimming of the display base material are required. Glass or tempered glass is generally used as a material having excellent mechanical properties in the display window or the front plate of the mobile device. However, the glass causes the mobile device to be heavier due to its own weight and there is a problem of breakage due to external impact.

Therefore, plastic resin is being researched as a substitute material for glass. Plastic resin films are lightweight and less prone to breakage, making them suitable for the trend toward lighter mobile devices. In particular, in order to achieve a film having characteristics of high hardness and wear resistance, a film for coating a hard coat layer made of a plastic resin on a supporting substrate has been proposed.

As a method of improving the surface hardness of the hard coating layer, a method of increasing the thickness of the hard coating layer may be considered. In order to secure a surface hardness sufficient to replace glass, it is necessary to implement a thickness of a hard coating layer. However, as the thickness of the hard coating layer is increased, the surface hardness can be increased. However, since wrinkles or curls increase due to hardening shrinkage of the hard coating layer, cracking or peeling of the hard coating layer is likely to occur. Is not easy.

On the other hand, aesthetically and functionally, a part of the display device is curved or flexible display has recently attracted attention, this trend is particularly prominent in mobile devices such as smartphones, tablet PCs. However, glass is not suitable for use as a cover plate for protecting such a flexible display, so it needs to be replaced with a plastic resin. However, for this purpose, there is a difficulty in preparing a film having sufficient flexibility while showing high hardness of glass.

The present invention exhibits high hardness while simultaneously realizing a balance between flexibility and high hardness properties, and is particularly easy to bendable, flexible, rollable, or foldable as the film is hardly damaged by repeated bending or folding operations. An optical laminated body which can be easily applied to a display device or the like is provided.

In addition, the present invention provides a display device including the optical laminate.

In the present specification, the substrate; And a hard coating layer formed on at least one surface of the substrate, the hard coating layer including two or more kinds of inorganic particles having a different average radius from that of the binder resin, wherein the hard coating layer has two or more first inorganics having an average radius of 10 to 15 nm. An optical stack, wherein a domain formed by enclosing two or more second inorganic particles having an average radius of 20 to 35 nm is formed, wherein the weight ratio of the first inorganic particle to the second inorganic particle is 1: 9 to 9: 1. Provide a sieve.

In addition, the present specification provides a display device including an optical laminate.

Hereinafter, an optical laminate and a display device according to specific embodiments of the present invention will be described in detail.

In the present specification, the term "flexible" refers to a state having flexibility such that no crack occurs over 3 mm in length when wound on a cylindrical mandrel having a diameter of 4 mm, and thus, the present invention. Flexible plastic film is applicable to bendable, flexible, rollable, cover film of foldable display and the like.

According to one embodiment of the invention, the substrate; And a hard coating layer formed on at least one surface of the substrate, the hard coating layer including two or more kinds of inorganic particles having a different average radius from that of the binder resin, wherein the hard coating layer has two or more first inorganics having an average radius of 10 to 15 nm. An optical stack, wherein a domain formed by enclosing two or more second inorganic particles having an average radius of 20 to 35 nm is formed, wherein the weight ratio of the first inorganic particle to the second inorganic particle is 1: 9 to 9: 1. Sieves may be provided.

The present inventors have conducted research on an optical laminate, a cover window, or an element substrate applicable to a display device having a thinner thickness, and have two or more first ones having an average radius of 10 to 15 nm on a hard coating layer formed on a predetermined substrate. Inorganic particles to form a domain formed by enclosing two or more second inorganic particles having an average radius of 20 to 35nm, wherein the weight ratio of the first inorganic particles to the second inorganic particles is 1: 9 to 9: 1 , High rigidity while simultaneously satisfying the balance of physical properties of flexibility and hardness, and exhibits almost no damage to the film, especially by repeated bending or folding operations, and thus is possible for flexible, flexible, rollable, or foldable mobile devices or displays. Experiments confirmed that it can be easily applied to the device and completed the invention.

Since the optical laminate may have physical properties that may replace the tempered glass, the optical laminate may not only be broken by pressure or force applied from the outside but may also be sufficiently curved and folded.

Physical properties such as bending durability and surface hardness of the optical laminate may be realized by optimization of the hard coating layer formed on the substrate. More specifically, the characteristics of the optical laminate may be due to the formation of the above-described domain.

The above-described domain formed on the hard coating layer has a high density packing structure in which first inorganic particles having a relatively small average radius are surrounded by second inorganic particles having a relatively large average radius, and are located therein. Therefore, compared with the case where only a single particle is distributed, the deformation and damage caused by external force may be relatively small. For this reason, the hard coating layer may have a higher surface hardness, and together with this, the optical laminate of the embodiment including the hard coating layer simultaneously satisfies the balance of flexibility and high hardness properties and is subjected to repeated bending or folding operations. It is also possible to prevent damage to the internal structure.

The “domain formed by enclosing at least two first inorganic particles having an average radius of 10 to 15 nm and at least two second inorganic particles having an average radius of 20 to 35 nm” is formed with the binder resin in the process of forming the hard coating layer. It can be formed by adjusting the mixing process of two or more kinds of inorganic particles having different average radius, adjusting the content of the components, in particular by controlling the drying rate of the formation process of the hard coating layer.

Accordingly, the thickness of the hard coating layer is not particularly limited, but may be formed by enclosing two or more first inorganic particles having an average radius of 10 to 15 nm by surrounding two or more second inorganic particles having an average radius of 20 to 35 nm. In order to more smoothly form the "domain", the hard coating layer is preferably applied and dried to have a thickness of a predetermined level or more.

For example, the hard coating layer may have a thickness of 25 μm or more, or 30 μm to 100 μm, and as the hard coating layer has such a thickness, the hard coating layer has two or more first ones having an average radius of 10 to 15 nm. A domain may be formed in which inorganic particles are surrounded by two or more second inorganic particles having an average radius of 20 to 35 nm. When the thickness of the hard coating layer is thin, for example, 20 μm or less, depending on the drying conditions, the coating liquid forming the hard coating layer dries within a relatively short time so that the coating layer rapidly increases in viscosity and the above-described domains are not formed. You may not.

The formation of the "domain formed by enclosing at least two first inorganic particles having an average radius of 10 to 15 nm and at least two second inorganic particles having an average radius of 20 to 35 nm" is performed by scanning electron microscope (SEM) and the like. It can be confirmed by using a device, and indirectly checking whether the domain is formed by measuring the distance between two or more second inorganic particles having an average radius of 20 to 35nm through incineration X-ray scattering analysis.

For example, the inorganic particles included in the hard coating layer may include first inorganic particles having an average radius of 10 to 15 nm and second inorganic particles having an average radius of 20 to 35 nm, and the hard coating layer may include 10 to 15 nm. As the domain is formed by enclosing two or more first inorganic particles having an average radius of two or more second inorganic particles having an average radius of 20 to 35 nm, the first inorganic particles having a central radius in the domain face each other. The distance Rd between the centers of two second inorganic particles may be 60 nm to 100 nm.

The distance (Rd) between the centers of the second inorganic particles of the domain of the inorganic particles can be measured and calculated through incineration X-ray scattering analysis of the radiation accelerator, for example, (Pohang) of the Light Accelerator Laboratory (Pohang Light Source) Using the SAXS beam-line 9A, merging the measured data set by the NIST SANS data reduction package, and using the model functions included in the NIST SANS package for data analysis (result fitting). .

The weight ratio of the first inorganic particles to the second inorganic particles in the hard coating layer may be 1: 9 to 9: 1. As described above, as the domains defined through the first inorganic particles and the second inorganic particles are formed in the hard coating layer, flexibility or durability against repeated bending or folding operations can be ensured. : When the weight ratio of the second inorganic particles deviates from 1: 9 to 9: 1, since the relative amount of the two inorganic particles for forming the domain is not sufficient, the domain may not be formed, and thus the hard coating layer The surface hardness of can be significantly lowered. Specifically, when the weight ratio of the first inorganic particles to the second inorganic particles in the hard coating layer deviates from 1: 9 to 9: 1, for example, the first inorganic particles in a weight ratio of 0.5: 9.5 or a weight ratio of 9.5: 0.5. When the second inorganic particles are present, the hard coating layer may exhibit a pencil hardness of 3H or less at a load of 750g.

As described above, the hard coating or the like includes two or more kinds of inorganic particles having a different average radius from that of the binder resin, and the two or more kinds of inorganic particles and the first inorganic particles having an average radius of 10 to 15 nm and 20 to 35 nm. It may include a second inorganic particles having an average radius of. The first inorganic particles may have an average radius of 10 to 15 nm, or 11 to 14 nm, or 12 to 13 nm, and the second inorganic particles may have an average radius of 20 to 35 nm, or 21 to 30 nm, or 22 to 26 nm. Can have.

As the inorganic particles included in the hard coating layer include first inorganic particles having an average radius of 10 to 15 nm and second inorganic particles having an average radius of 20 to 35 nm, the above-described domains are more easily included in the hard coating layer. Can be generated.

More specifically, the first inorganic particles having an average radius of 10 to 15nm: the average radius ratio of the second inorganic particles having an average radius of 20 to 35nm is 1: 1.2 or more, or 1: 1.5 or more, or 1: 2 It may be greater than or equal to 1:20 or less. When the average radius ratio of the second inorganic particles to the first inorganic particles is too small, the size of the two types of particles may be similar to prevent the formation of a domain having high density particle packing. When the average radius ratio of the second inorganic particles to the first inorganic particles is too large, the size of the above-described domain may be increased, and the haze of the hard coating layer may be greatly increased.

The average radius of each of the first inorganic particles and the second inorganic particles can be confirmed through a commonly known method, for example, measuring the radius of individual particles identified in an electron micrograph (SEM, TEM, etc.) of the hard coating layer. It can be calculated and derived, or the average radius of the inorganic particles calculated through the X-ray scattering experiment.

On the other hand, the first inorganic particles may have an average radius of 10 to 15nm, wherein the radius of the individual inorganic particles that can form a domain of the individual inorganic particles included in the first inorganic particles is ± 5nm of the average radius Range. For example, the radius of the individual inorganic particles included in the first inorganic particle and forming the domain may be included in the range of 5 to 20 nm.

In addition, the second inorganic particles may have an average radius of 20 to 35nm, wherein the radius of the individual inorganic particles that can form a domain of the individual inorganic particles included in the second inorganic particles is ± 5nm of the average radius Range. For example, the radius of the individual inorganic particles included in the second inorganic particles and forming the domain may be included in the range of 15 to 40 nm.

Two or more kinds of inorganic particles having different average radii may be, for example, metal atoms such as silica, aluminum, titanium, or zinc, or oxides or nitrides thereof, and are each independently silica fine particles, aluminum oxide particles, titanium oxide particles, Or zinc oxide particles may be used.

On the other hand, as described above, the hard coating layer may exhibit a pencil hardness of 5H or more, or 6H or more, or 7H or more at a load of 750g.

As described above, in a film or optical laminate having a thin thickness, flexibility can be secured, but it is not easy to secure durability against repeated bending or folding operations while securing high surface strength.

On the contrary, the hard coating layer included in the optical laminate of the embodiment may have the above-described surface hardness, and at the same time, both sides of the optical laminate are disposed on the bottom surface at a distance of 5 mm in the middle of the optical laminate. It may have a characteristic that no crack occurs when it is folded at 90 degrees with respect to 100,000 times at room temperature.

On the other hand, the content of two or more kinds of inorganic particles different within the range in which the domain is formed on the hard coating layer is not limited significantly, preferably the hard coating layer is the first inorganic particles and the second inorganic to the weight of the binder resin 100 The total particle size may include 20 to 80 parts by weight.

When the content of two or more different kinds of inorganic particles included in the hard coating layer is too small, it may be difficult to form the domain or the hardness of the hard coating layer may be lowered. In addition, when the content of two or more different inorganic particles included in the hard coating layer is too high, the hardness may be increased, but the flexibility of the optical laminate may be greatly reduced, or the durability against repeated bending or folding operations may also be reduced.

The hard coating layer may include a binder resin.

Specific examples of the binder resin are not limited, and may be, for example, polymers or copolymers of monomer (s) having a photocurable reactor, and specifically, (meth) acrylate monomers or oligomers, vinyl monomers or oligomers, and the like. It may be a polymer or copolymer formed from.

For example, the binder resin may include a polymer or copolymer of 3 to 6 functional (meth) acrylate monomers.

The 3 to 6 functional acrylate monomer or oligomer is trimethylolpropane triacrylate (TMPTA), trimethylolpropaneethoxy triacrylate (TMPEOTA), glycerin propoxylated triacrylate (GPTA), pentaerythritol tetra Acrylate (PETA), dipentaerythritol hexaacrylate (DPHA), and the like. The 3 to 6 functional acrylate monomers or oligomers may be used alone or in combination with each other.

The (meth) acrylate monomer or oligomer or vinyl monomer or oligomer has a weight average molecular weight (Mw) of about 200 to about 2,000 g / mol, or about 200 to about 1,000 g / mol, or about 200 to about 500 g It may range from / mol.

The 3-6 functional acrylate-based binder may have an acrylate equivalent weight in the range of about 50 to about 300 g / mol, or about 50 to about 200 g / mol, or about 50 to about 150 g / mol. Can be.

When the weight average molecular weight and the acrylate equivalent weight of the 3 to 6 functional acrylate-based binder are in the above-mentioned range, respectively, a coating layer of more optimized physical properties may be formed.

On the other hand, the substrate can be used without any great variety of supporting substrates known to be applicable to the optical film or optical element.

For example, the substrate has an optical modulus of at least about 4 GPa as measured according to ASTM D882 so that the optical laminate can ensure flexibility and hardness, and has an optical thickness in the range of 20 to 300 μm. It is a transparent plastic resin for resin, It can be used without a restriction | limiting in particular in the manufacturing method or material of supporting base materials, such as a stretched film or a non-stretched film.

Among the conditions of the substrate, the elastic modulus may be about 4 GPa or more, or about 5 GPa or more, or about 5.5 GPa, or about 6 GPa or more, and the upper limit may be about 9 GPa or less, or about 8 GPa or less, or about 7 GPa or less. have. If the elastic modulus is less than 4 GPa, it may not be able to achieve sufficient hardness and if it is too high above 9 GPa, it may be difficult to form a flexible film.

In addition, the thickness of the support substrate may be about 20 μm or more, or about 25 μm or more, or about 30 μm or more, and the upper limit thereof may be about 300 μm or less, or about 200 μm or less, or about 150 μm or less, Or about 100 μm or less. If the thickness of the substrate is less than 20㎛, there is a fear that the coating layer forming process, or curl (curl) may occur, it may be difficult to achieve high hardness. On the other hand, when the thickness exceeds 300㎛, it may be difficult to form a flexible film due to the lack of flexibility.

The substrate satisfies the above-mentioned elastic modulus and thickness range, for example, polyimide (PI), polyimideamide, polyetherimide (PEI), polyethylene terephthalate (polyethyleneterephtalate, PET), polyethylenenaphthalate (PEN), polyetheretherketon (PEEK), cyclic olefin polymer (COP), polyacrylate (PAacrylate), polymethylmethacrylate (polymethylmethacrylate) , PMMA), or a film containing triacetylcellulose (TAC). The support substrate may be a single layer or a multilayer structure including two or more substrates made of the same or different materials as necessary, but is not particularly limited.

On the other hand, in the optical laminate of the above embodiment, a hard domain is formed in which two or more first inorganic particles having an average radius of 10 to 15 nm are surrounded by two or more second inorganic particles having an average radius of 20 to 35 nm. A coating layer may be formed on one surface of the substrate, and a second hard coating layer containing a binder resin including a polymer or a copolymer of a (meth) acrylate monomer may be formed on the other surface of the substrate.

As the second hard coating layer is formed together with the hard coating layer described above, the balance of flexibility and high hardness of the optical laminate may be more improved, and durability and dent resistance to repeated bending or folding operations may be improved. ) Can also be improved.

The thickness of each of the hard coating layer and the second hard coating layer formed with a domain formed by enclosing the two or more first inorganic particles having an average radius of 10 to 15 nm surrounded by two or more second inorganic particles having an average radius of 20 to 35 nm Although not particularly limited, when the combined thickness of the hard coating layer and the second hard coating layer is excessively large, flexibility of the optical laminate or durability against repeated bending or folding operations may be reduced. Accordingly, it is preferable that each of the hard coating layer and the second hard coating layer has a thickness of 30 μm to 100 μm.

On the other hand, the optical laminate may be provided by coating and photocuring the coating composition comprising the above-described components on at least one side of the substrate. The method of applying the coating composition is not particularly limited as long as it can be used in the art to which the present technology belongs, for example bar coating method, knife coating method, roll coating method, blade coating method, die coating method, micro gravure coating Method, comma coating method, slot die coating method, lip coating method, solution casting (solution casting) method and the like can be used.

In the optical laminate, a plastic resin film, an adhesive film, a release film, a conductive film, a conductive layer, a liquid crystal layer, a coating layer, a cured resin layer, a non-conductive film, a metal mesh layer, between the hard coating layer upper surface or the base film and the hard coating layer. It may further include one or more layers, films, films, and the like, such as a patterned metal layer.

For example, a conductive antistatic layer is first formed on a substrate and then a coating layer is formed thereon to provide an anti-static function or a low refractive index layer is introduced on the coating layer to provide a low reflection function. It can also be implemented.

In addition, the layer, film, film or the like may be in any form of a single layer, a double layer or a laminate. The layer, film, or film may be laminated on the coating layer by a method such as laminating a freestanding film using an adhesive or an adhesive film, or by coating, vapor deposition, sputtering, or the like. It is not limited to this.

On the other hand, the hard coating layer, in addition to the binder resin, inorganic fine particles and the like, photoinitiator, organic solvent, surfactant, UV absorber, UV stabilizer, yellowing agent, leveling agent, antifouling agent, dye technology for improving the color value It may further include components conventionally used in the field. In addition, since the content can be variously adjusted within a range that does not lower the physical properties of the hard coating layer, it is not particularly limited, for example, may be included in about 0.01 to about 30 parts by weight based on 100 parts by weight of the hard coating layer.

The surfactant may be a 1 to 2 functional fluorine-based acrylate, a fluorine-based surfactant or a silicone-based surfactant. In this case, the surfactant may be included in the form of being dispersed or crosslinked in the hard coating layer.

The additive may include a UV absorber or a UV stabilizer, and the UV absorber may include a benzophenone compound, a benzotriazole compound, a triazine compound, and the like. Tetramethyl piperidine and the like.

Examples of the photoinitiator include 1-hydroxycyclohexyl-phenyl ketone, 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-hydroxy-1- [4- (2-hydroxyethoxy ) Phenyl] -2-methyl-1-propanone, methylbenzoylformate, α, α-dimethoxy-α-phenylacetophenone, 2-benzoyl-2- (dimethylamino) -1- [4- (4- Morpholinyl) phenyl] -1-butanone, 2-methyl-1- [4- (methylthio) phenyl] -2- (4-morpholinyl) -1-propanone diphenyl (2,4, 6-trimethylbenzoyl) -phosphine oxide, or bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, and the like. Commercially available products include Irgacure 184, Irgacure 500, Irgacure 651, Irgacure 369, Irgacure 907, Darocur 1173, Darocur MBF, Irgacure 819, Darocur TPO, Irgacure 907, and Esacure KIP 100F. These photoinitiators can be used individually or in mixture of 2 or more types different from each other.

Examples of the organic solvent include alcohol solvents such as methanol, ethanol, isopropyl alcohol and butanol, alkoxy alcohol solvents such as 2-methoxyethanol, 2-ethoxyethanol and 1-methoxy-2-propanol, acetone and methyl Ketone solvents such as ethyl ketone, methyl isobutyl ketone, methyl propyl ketone, cyclohexanone, propylene glycol monopropyl ether, propylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, Ether solvents such as diethylene glycol monomethyl ether, diethyl glycol monoethyl ether, diethyl glycol monopropyl ether, diethyl glycol monobutyl ether, diethylene glycol-2-ethylhexyl ether, benzene, toluene, xylene and The same aromatic solvents can be used alone or in combination.

On the other hand, the optical laminate of the embodiment may have a light transmittance of 88.0% or more, or 90.0% or more, haze of 1.5% or less, or 1.0% or less, or 0.5% or less.

Meanwhile, according to another embodiment of the present invention, a display device including the optical stack of the above embodiment may be provided.

The display device is not only flat, but also curved, bendable, flexible, rollable, or foldable type of mobile communication terminal, smartphone, or tablet PC. Touch panels, and various displays.

An example of the display device may be a flexible light emitting display device. The light emitting device display device may use the polymer film of the embodiment as a substrate, an outer protective film or a cover window. Specifically, the light emitting device display device may be an organic light emitting diode (OLED) display using the polymer film of the embodiment as a cover window. Except for using the polymer film as a cover window, it may include a device portion known as a component of a conventional organic light emitting diode (OLED) display.

For example, the organic light emitting diode (OLED) display may include a cover window including a polymer film located at an outer portion of the light or screen direction, and provides a cathode and an electron transport layer to provide electrons. A layer, an emission layer, a hole transport layer, and an anode for providing holes may be sequentially formed.

In addition, the organic light emitting diode (OLED) display may further include a hole injection layer (HIL) and an electron injection layer (EIL).

In order for the organic light emitting diode (OLED) display to function and operate as a flexible display, in addition to using the polymer film as a cover window, the electrodes of the cathode and the anode and each component may be formed of a material having a predetermined elasticity. Can be used

An example of the display device may be a rollable display or a foldable display including the optical stack of the embodiment.

The optical stack may be used as a substrate, an outer protective film or a cover window in a rollable display device. The polymer film may not only be broken by pressure or force applied from the outside, but may also have elasticity or flexibility that can be sufficiently bent and folded.

The rollable display device may include the polymer film of the embodiment, together with a light emitting device and a module in which the light emitting device is located, and the light emitting device and the module may also have elasticity or flexibility enough to bend and fold sufficiently. have.

The rollable display device may have various structures according to an application field and a specific shape, and may include, for example, a cover plastic window, a touch panel, a polarizer, a barrier film, a light emitting device (such as an OLED device), a transparent substrate, and the like. Can be.

According to the present invention, high hardness is achieved while simultaneously satisfying the balance between physical properties of flexibility and high hardness, and in particular, there is almost no damage to the film even by repeated bending or folding operations, and thus it is flexible, flexible, rollable, or foldable mobile. There may be provided an optical laminate and a display device including the optical laminate which can be easily applied to an apparatus or a display apparatus.

Since the optical laminate may have physical properties that can replace tempered glass, the optical laminate may not only be broken by pressure or force applied from the outside, but may also be sufficiently curved and folded, and may have flexibility, Flexibility, high hardness, scratch resistance, high transparency and less damage to the film under repeated, continuous bending or prolonged folding, resulting in bendable, flexible, rollable, or foldable It can be usefully applied to mobile devices, display devices, front panels of various instrument panels, display units, and the like.

FIG. 1 schematically shows a cross section of a domain formed in a hard coat layer included in an optical laminate of one embodiment. FIG.
FIG. 2 shows the results of incineration X-ray scattering measurement of the hard coating layer of Example 1 using two kinds of inorganic particles and a result of fitting the result (black line).
FIG. 3 shows the results of incineration X-ray scattering measurement of the hard coating layer using one kind of inorganic particles (diameter 13 nm) and the result of fitting the result (black line).
Fig. 4 shows the results of incineration X-ray scattering measurement for the hard coating layer using one kind of inorganic particles (diameter of 25 nm) and the result of fitting the result (black line).

Hereinafter, the operation and effects of the invention will be described in more detail with reference to specific examples of the invention. However, these embodiments are only presented as an example of the invention, whereby the scope of the invention is not determined.

Preparation Example: Preparation of Coating Liquid for Hard Coating Layer Formation

To prepare a coating liquid for forming a hard coat layer by mixing the components shown in Tables 1 to 3 (in Tables 1 to 3 below, R means the average radius of the inorganic particles calculated through X-ray scattering experiments).

(Unit: g) Production Example
One Production Example
2 Production Example
3 Production Example
4 Production Example
5 Production Example
6 Production Example
7 Binder Monomer TMPTA 10 10 10 10 10 10 10 PETA 20 20 20 20 20 20 20 DPEPA 20 20 20 20 20 20 20 TPGDA 5 5 5 5 5 5 5 TA-604AU 5 5 5 5 5 5 5 weapon SiO ₂ (R = 13 nm) 20 10 30 4 36 2 38 particle SiO ₂ (R = 25 nm) 20 30 10 36 4 38 2 Leveling agent 0.06 0.06 0.06 0.06 0.06 0.06 0.06 Photoinitiator 0.72 0.72 0.72 0.72 0.72 0.72 0.72 Organic solvent
(Methyl Ethyl Ketone) 50 50 50 50 50 50 50

(Unit: g) Preparation Example 8 Preparation Example 9 Preparation Example 10 Preparation Example 11 Preparation Example 12 Preparation Example 13 Preparation Example 14 Binder Monomer TMPTA 10 10 10 10 10 10 10 PETA 20 20 20 20 20 20 20 DPEPA 20 20 20 20 20 20 20 TPGDA 5 5 5 5 5 5 5 TA-604AU 5 5 5 5 5 5 5 weapon TiO ₂ (R = 12 nm) 20 10 30 4 36 2 38 particle TiO ₂ (R = 24 nm) 20 30 10 36 4 38 2 Leveling agent 0.06 0.06 0.06 0.06 0.06 0.06 0.06 Photoinitiator 0.72 0.72 0.72 0.72 0.72 0.72 0.72 Organic solvent
(Methyl Ethyl Ketone) 50 50 50 50 50 50 50

(Unit: g) Preparation Example 15 Preparation Example 16 Preparation Example 17 Preparation Example 18 Preparation Example 19 Preparation Example 20 Preparation Example 21 Preparation Example 22 Binder Monomer TMPTA 10 10 10 10 10 10 10 10 PETA 20 20 20 20 20 20 20 10 DPEPA 20 20 20 20 20 20 20 10 TPGDA 5 5 5 5 5 5 5 20 TA-604AU 5 5 5 5 5 5 5 50 weapon ZrO ₂ (R = 12 nm) 20 10 30 4 36 2 38 particle ZrO ₂ (R = 24 nm) 20 30 10 36 4 38 2 Leveling agent 0.06 0.06 0.06 0.06 0.06 0.06 0.06 0.1 Photoinitiator 0.72 0.72 0.72 0.72 0.72 0.72 0.72 1.21 Organic solvent
(Methyl Ethyl Ketone) 50 50 50 50 50 50 50 30

ingredient Chemical name / product name manufacturer Molecular Weight
(g / mol) Acrylate Count Acrylate Equivalent TMPTA Trimethylolpropane Triacrylate 338 3 113 PETA Pentaerythritol Tetraacryl 352 4 88 DPEPA Dipentaerythritol Pentaacrylate 525 5 105 TPGDA Tripropyleneglycol Diacrylate 300 2 150 TA-604AU Ilyu Corporation 2300 3 767 Leveling agent F477 DIC Corporation Photoinitiator Irgacure 127 Ciba Specialty Chamicals

[Examples and Comparative Examples: Production of Optical Laminates]

The coating composition shown in the following table is applied to a polyimide substrate (size: 20 cm x 30 cm, thickness: 35 µm) having an elastic modulus value of 6.0 GPa measured according to ASTM D882 by a bar or slot coating method, and the air atmosphere is 80 degrees for 3 minutes. Dried under. The optical laminated body was manufactured by photocuring with the metal halide lamp (light quantity: 200mJ / cm <2>) of the wavelength of 290-320 nm. The photocuring was carried out in a nitrogen or argon atmosphere, the light irradiation time is 30 seconds.

Experimental Example: Measurement of Physical Properties of Optical Laminate

Experimental Example 1 Domain Identification of Inorganic Particles and Measurement of Distance (Rd) Between Centers of Two Second Inorganic Particles in a Domain

(1) Intensity vs. secured by incineration X-ray scattering method The wavevector (q) curve was fitted using a model function included in the NIST SANS package to determine whether domains of inorganic particles were formed on Hard 1 (front) of the optical laminate of each of Examples and Comparative Examples. The distance Rd between the centers of two second inorganic particles in the domain of the inorganic particle was determined.

FIG. 2 shows the results of incineration X-ray scattering measurement of the hard coating layer of Example 1 using two kinds of inorganic particles, respectively, and a result of optimizing the results (black line), respectively, in FIGS. 3 and 4. The results of the incineration X-ray scattering measurement of the hard coating layer using the kinds of inorganic particles (diameter 13 nm and diameter 25 nm) and the results obtained by fitting the result (black line) are shown.

1) device

U-SAXS beam-line 9A from Pohang Light Source

<Measurement conditions>

 E = 11.1 KeV, 19.9 keV,

ΔE / E = 2 * 10 ^-4

q range used: 0.0024 ≤ q (Å ^-1 ) ≤ 0.5

 Sample to detector distance (SDD; 6.5 m (11.1keV), 2.5m (19.9keV))

 Pin holes collimated

2D CCD Detector (Rayonix SX165, USA)

2) How to measure

Film-type samples are attached to the sample holder using transparent tape.

The 2D image obtained in the experiment was averaged in a circle on the beam stop basis and converted into a 1D image (the unit is arbitrary unit, a.u. since the intensity value of the experimental data was not changed to an absolute value).

Two data sets per sample measured at 6.5 m SDD at energy of 11.1 KeV and 2.5 m SDD at energy of 19.9 keV are merging by NIST SANS data reduction package. The included model function was used.

Experimental Example 2: Pencil Hardness

Examples and Comparative Examples With respect to the hard coating layer formed on the front surface of each optical laminate, scratches were made after reciprocating three times with a load of 750 g and an angle of 45 degrees according to the measurement standard JIS K5400-5-4 using a pencil hardness tester. The maximum hardness was confirmed.

The physical property measurement results are shown in Tables 5 to 6 below.

Hard 1 (Front) Hard 2 (back) face
Pencil hardness
Inorganic Particle Domain
Formation
Rd
(Nm)
Furtherance thickness
(um) Furtherance thickness
(um) Example 1 Preparation Example 1 40 Preparation Example 22 70 8H ○ About 60-75 Example 2 Preparation Example 8 40 Preparation Example 22 70 8H ○ About 65-80 Example 3 Preparation Example 15 40 Preparation Example 22 70 8H ○ 80 ~ 100 Example 4 Preparation Example 2 40 Preparation Example 22 70 7H ○ About 60-70 Example 5 Preparation Example 3 40 Preparation Example 22 70 7H ○ About 65-75 Example 6 Preparation Example 9 40 Preparation Example 22 70 7H ○ About 65-75 Example 7 Preparation Example 10 40 Preparation Example 22 70 7H ○ 70-80 Example 8 Preparation Example 16 40 Preparation Example 22 70 7H ○ About 80 ~ 90 Example 9 Preparation Example 17 40 Preparation Example 22 70 7H ○ About 90-100 Example 10 Preparation Example 4 40 Preparation Example 22 70 5H ○ About 60-65 Example 11 Preparation Example 5 40 Preparation Example 22 70 5H ○ 70-75 Example 12 Preparation Example 11 40 Preparation Example 22 70 5H ○ About 65-70 Example 13 Preparation Example 12 40 Preparation Example 22 70 5H ○ About 75 ~ 80 Example 14 Preparation Example 18 40 Preparation Example 22 70 5H ○ 80-85 Example 15 Preparation Example 19 40 Preparation Example 22 70 5H ○ About 95-100

Hard 1 (Front) Hard 2 (back) face
Pencil hardness Inorganic Particle Domain
Formation Rd
(Nm) Furtherance thickness
(um) Furtherance thickness
(um) Comparative Example 1 Preparation Example 6 40 Preparation Example 22 70 3H X - Comparative Example 2 Preparation Example 7 40 Preparation Example 22 70 3H X - Comparative Example 3 Preparation Example 13 40 Preparation Example 22 70 3H X - Comparative Example 4 Preparation Example 14 40 Preparation Example 22 70 3H X - Comparative Example 5 Preparation Example 20 40 Preparation Example 22 70 3H X - Comparative Example 6 Preparation Example 21 40 Preparation Example 22 70 3H X - Comparative Example 7 Preparation Example 1 20 Preparation Example 22 70 2H X - Comparative Example 8 Preparation Example 8 20 Preparation Example 22 70 2H X - Comparative Example 9 Preparation Example 15 20 Preparation Example 22 70 2H X - Comparative Example 10 Preparation Example 2 20 Preparation Example 22 70 2H X - Comparative Example 11 Preparation Example 3 20 Preparation Example 22 70 2H X - Comparative Example 12 Preparation Example 9 20 Preparation Example 22 70 2H X - Comparative Example 13 Preparation Example 10 20 Preparation Example 22 70 2H X - Comparative Example 14 Preparation Example 16 20 Preparation Example 22 70 2H X - Comparative Example 15 Preparation Example 17 20 Preparation Example 22 70 2H X - Comparative Example 16 Preparation Example 4 20 Preparation Example 22 70 2H X - Comparative Example 17 Preparation Example 5 20 Preparation Example 22 70 2H X - Comparative Example 18 Preparation Example 11 20 Preparation Example 22 70 2H X - Comparative Example 19 Preparation Example 12 20 Preparation Example 22 70 2H X - Comparative Example 20 Preparation Example 18 20 Preparation Example 22 70 2H X - Comparative Example 21 Preparation Example 19 20 Preparation Example 22 70 2H X - Comparative Example 22 Preparation Example 6 20 Preparation Example 22 70 2H X - Comparative Example 23 Preparation Example 7 20 Preparation Example 22 70 2H X - Comparative Example 24 Preparation Example 13 20 Preparation Example 22 70 2H X - Comparative Example 25 Preparation Example 14 20 Preparation Example 22 70 2H X - Comparative Example 26 Preparation Example 20 20 Preparation Example 22 70 2H X - Comparative Example 27 Preparation Example 21 20 Preparation Example 22 70 2H X -

As shown in Tables 5 to 6, the hard coating layer formed on the front surface of the optical laminate of the embodiments includes "two or more first inorganic particles having an average radius of 10 to 15 nm and two or more second having an average radius of 20 to 35 nm. Domains formed by surrounding inorganic particles " are formed, wherein the weight ratio of the first inorganic particles to the second inorganic particles is 1: 9 to 9: 1, and the optical laminate of these embodiments has a high surface hardness of 5H or more. It is confirmed that it has, so that it can have sufficient flexibility while exhibiting high hardness of glass level.

In contrast, the optical laminates of the comparative examples, unlike the embodiment, have a weight ratio of the first inorganic particles to the second inorganic particles in the range of 1: 9 to 9: 1 or do not form domains of the inorganic particles. It has been confirmed that the optical laminate of these has a relatively low surface hardness.

Claims (12)

materials; And
And a hard coating layer formed on at least one surface of the substrate and including two or more kinds of inorganic particles having an average radius different from that of the binder resin.
The hard coating layer is formed with a domain formed by enclosing two or more first inorganic particles having an average radius of 10 to 15nm surrounded by two or more second inorganic particles having an average radius of 20 to 35nm,
The weight ratio of the first inorganic particles to the second inorganic particles is 1: 9 to 9: 1, the optical laminate.
The method of claim 1,
The hard coat layer exhibits a pencil hardness of at least 5H at a load of 750 g.
The method of claim 1,
And the hard coat layer has a thickness of 25 μm or more.
The method of claim 1,
And the hard coat layer has a thickness of 30 μm to 100 μm.
The method of claim 1,
And the distance (Rd) between the centers of two second inorganic particles positioned opposite to each other with the first inorganic particles centrally located in the domain is 60 nm to 100 nm.
The method of claim 1,
The hard coating layer comprises an total of 20 to 80 parts by weight of the total amount of the first inorganic particles and the second inorganic particles relative to 100 weight of the binder resin.
The method of claim 1,
The binder resin is an optical laminate comprising a polymer or copolymer of 3 to 6 functional (meth) acrylate monomers.
The method of claim 1,
The hard coat layer is formed on one surface of the substrate,
The other laminated body of the said base material is an optical laminated body in which the 2nd hard-coat layer containing the binder resin containing the polymer or copolymer of a (meth) acrylate type monomer is formed.
The method of claim 8,
The second hard coating layer has a thickness of 30 ㎛ to 100 ㎛, the optical laminate.
The method of claim 1,
The substrate having a thickness of 20 μm to 300 μm.
The method of claim 1,
The optical laminate is used as a cover window or an element substrate of a flexible display device.
A display device comprising the optical stack of claim 1.

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