KR102508111B1 - Quantum dot optical film and quantum dot composition comprised therein - Google Patents

Abstract

The present invention relates to a quantum dot optical film and a quantum dot composition included therein, wherein the quantum dot optical film includes a base film; and disposed on the base film, a polymer matrix; and a quantum dot-containing layer including a plurality of quantum dots dispersed in the polymer matrix, wherein the polymer matrix includes a bifunctional (meth)acrylate monomer and a trifunctional (meth)acrylate monomer, and a tetrafunctional or higher polyfunctional (meth)acrylate monomer. photopolymerizable monomers including acrylate monomers; and a light diffusing agent selected from the group consisting of zinc oxide, titanium dioxide, and mixtures thereof.

Description

Quantum dot optical film and quantum dot composition contained therein

The present invention relates to a quantum dot optical film and a quantum dot composition included therein, and more particularly, to a quantum dot optical film having improved optical properties and reduced manufacturing cost, and a quantum dot composition included therein.

Quantum dot (QD) is a so-called semiconductor nanocrystals, which can generate various colors by generating light of different wavelengths for each particle size without changing the type of material, and is said to have higher color purity and light stability than conventional light emitting materials. Due to its advantages, it is attracting attention as a next-generation light emitting device. Quantum dots are dispersed in a polymer matrix and applied to a display in the form of a quantum dot-polymer composite, playing a major role in realizing high luminance and high color reproduction of displays. However, there is a problem in that the optical properties of quantum dots are easily affected by the physical properties and composition ratio of organic/inorganic compounds constituting the polymer composite.

The present invention is to solve the above problems, and by adjusting the physical properties and composition ratio of organic and inorganic compounds constituting the quantum dot-polymer composite, the quantum dot-polymer composite can control optical properties such as refractive index and luminance. An object of the present invention is to provide a polymer composite and a quantum dot optical film using the same.

In order to achieve the above technical problem, the present invention is a base film; and disposed on the base film, a polymer matrix; and a quantum dot-containing layer including a plurality of quantum dots dispersed in the polymer matrix, wherein the polymer matrix includes a bifunctional (meth)acrylate monomer and a trifunctional (meth)acrylate monomer, and a tetrafunctional or higher polyfunctional (meth)acrylate monomer. photopolymerizable monomers including acrylate monomers; and a cured product of a photocurable composition including a light diffusing agent selected from the group consisting of zinc oxide, titanium dioxide, and mixtures thereof.

In addition, the present invention is a quantum dot; a photopolymerizable monomer including a bifunctional (meth)acrylate monomer, a trifunctional (meth)acrylate monomer, and a tetrafunctional or higher functional (meth)acrylate monomer; and a light diffusing agent selected from the group consisting of zinc oxide, titanium dioxide, and mixtures thereof.

The quantum dot optical film according to the present invention includes a photopolymerizable monomer including a bifunctional (meth)acrylate monomer, a trifunctional (meth)acrylate monomer, and a tetrafunctional or higher multifunctional (meth)acrylate monomer; and a light-diffusing agent selected from the group consisting of zinc oxide, titanium dioxide, and mixtures thereof, thereby enabling optimal refractive index setting, optimizing quantum dot content, and maximizing optical properties, as well as cost reduction. can indicate

1 is a schematic cross-sectional view of a quantum dot optical film according to a first embodiment of the present invention.
2 is a schematic cross-sectional view of a quantum dot optical film according to a second embodiment of the present invention.

Hereinafter, the present invention will be described.

All terms (including technical and scientific terms) used in this specification, unless otherwise defined, may be used in a meaning commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in commonly used dictionaries are not interpreted ideally or excessively unless explicitly specifically defined.

In addition, throughout this specification, when a certain component is said to "include", it means that it may further include other components, not excluding other components, unless otherwise stated. In addition, throughout the specification, "above" or "on" means not only the case of being located above or below the target part, but also the case of another part in the middle thereof, and must necessarily specify the direction of gravity It does not mean that it is located above the standard.

In addition, in this specification, “(meth)acrylate” represents acrylate and methacrylate, “(meth)acryl” represents acryl and methacryl, and “(meth)acryloyl” represents acryloyl. and methacryloyl.

In addition, in this specification, "monomer" and "monomer" have the same meaning. Monomers in the present invention are distinguished from oligomers and polymers and refer to compounds having a weight average molecular weight of 1,000 or less. In this specification, "polymerizable functional group" refers to a group involved in a polymerization reaction, such as a (meth)acrylate group.

<Quantum dot composition>

The quantum dot composition according to the present invention is a composition for forming a film (or sheet) containing quantum dots, and is a layer containing a polymer matrix and a plurality of quantum dot (QD) particles dispersed in the polymer matrix (hereinafter referred to as 'quantum dot-containing layer'). It is a curable composition that forms.

According to one example, the quantum dot composition of the present invention is quantum dots; a photopolymerizable monomer including a bifunctional (meth)acrylate monomer, a trifunctional (meth)acrylate monomer, and a tetrafunctional or higher functional (meth)acrylate monomer; and a light diffusing agent selected from the group consisting of zinc oxide, titanium dioxide, and mixtures thereof. Optionally, it may further contain a barrier material, photoinitiator and/or additive.

Hereinafter, the composition of the quantum dot composition according to the present invention will be described.

(a) quantum dots

In the quantum dot composition of the present invention, the quantum dot (Quantum Dot, QD) is a nano-sized semiconductor material, and may have different energy band gaps depending on the size and composition, and thus emit light of various emission wavelengths.

These quantum dots have a homogeneous monolayer structure; a multilayer structure such as a core-shell type, a gradient structure, and the like; or a mixture thereof. When the shell has multiple layers, each layer may contain components different from each other, such as (semi)metal oxides.

The quantum dot (QD) may be freely selected from a group II-VI compound, a group III-V compound, a group IV-VI compound, a group IV element, a group IV compound, and combinations thereof. When the quantum dot is in the core-shell form, the core and the shell may be freely composed of the components exemplified below, respectively.

In one example, the II-VI compound is a binary element compound selected from the group consisting of CdO, CdS, CdSe, CdTe, ZnO, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, MgSe, MgS, and mixtures thereof; A ternary selected from the group consisting of CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, MgZnSe, MgZnS and mixtures thereof bovine compounds; and CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and quaternary compounds selected from the group consisting of mixtures thereof.

In another example, the group III-V compound is a binary element compound selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; A ternary compound selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, and mixtures thereof; And it may be selected from the group consisting of quaternary compounds selected from the group consisting of GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof. there is.

In another example, the group IV-VI compound is a binary compound selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; a ternary compound selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; And it may be selected from the group consisting of quaternary compounds selected from the group consisting of SnPbSSe, SnPbSeTe, SnPbSTe, and mixtures thereof.

In another example, the group IV element may be selected from the group consisting of Si, Ge, and mixtures thereof. The group IV compound may be a binary element compound selected from the group consisting of SiC, SiGe, and mixtures thereof.

The above-mentioned two-element compound, three-element compound, or quaternary element compound may be present in the particle at a uniform concentration or may be present in the same particle in a state in which the concentration distribution is partially different. Also, one quantum dot may have a core/shell structure surrounding another quantum dot. The interface between the core and the shell may have a concentration gradient in which the concentration of elements present in the shell decreases toward the center.

A part of the surface of the quantum dot may be substituted with an organic ligand. These organic ligands may play a role of stabilizing the quantum dots by being bonded to the surface of the quantum dots. Non-limiting examples of usable organic ligands include C ₅ to C ₂₀ alkyl carboxylic acids, alkenyl carboxylic acids or alkynyl carboxylic acids; pyridine; mercapto alcohol; thiol; phosphine; phosphine oxide; primary amine; secondary amine; or combinations thereof. A method of substituting a part of the surface of the quantum dot with an organic ligand is not limited in the present invention, and a conventional method performed in the art may be used.

The shape of the quantum dot is not particularly limited as long as it is a shape commonly used in the art. For example, spherical, rod-shaped, pyramidal, disc-shaped, multi-arm, or cubic nanoparticles, nanotubes, nanowires, nanofibers, nanoplatelet particles etc. can be used.

In addition, the size of the quantum dots is not particularly limited and may be appropriately adjusted within a common range known in the art. For example, the average particle diameter (D ₅₀ ) of the quantum dots may be 2 to 10 nm. In this way, when the particle diameter of the quantum dots is controlled to be in the range of about 2 to 10 nm, light of a desired color can be emitted. For example, when the particle diameter of the quantum dot core containing InP is 5 to 6 nm, light having a wavelength of 520 to 550 nm can be emitted, while the particle diameter of the quantum dot core containing InP is 7 to 8 nm, It can emit light with a wavelength of 620 to 640 nm. For example, as the blue-emitting QD (Quantum dot), a non-cadmium (Cd) group III-V QD (eg, InP, InGaP, InZnP, GaN, GaAs, GaP) can be used.

In addition, the quantum dots may have a full width of half maximum (FWHM) of an emission wavelength spectrum of 40 nm or less, and color purity or color reproducibility may be improved within this range. In addition, since light emitted through the quantum dots is emitted in all directions, a wide viewing angle may be improved.

If necessary, the quantum dots may further include a polymer coating layer formed on part or all of the surface. The polymer coating layer may include a polymer resin known in the art, such as a thermosetting polymer resin, a photocurable polymer resin, or a combination thereof. Specifically, it may be a resin selected from the group consisting of (meth)acrylic resins, urethane acrylate-based resins, and combinations thereof. The polymer constituting the polymer coating layer may include a functional resin having no substituent or at least one substituent selected from the group consisting of an acrylate group, an acryloyl group, a vinyl group, a thiol group, and combinations thereof.

In the present invention, the content of the quantum dot may be appropriately adjusted within a range known in the art, and may be, for example, 1 to 14 parts by weight based on 100 parts by weight of the total amount of the quantum dot composition. Accordingly, the quantum dot-containing layer formed of the quantum dot composition of the present invention may include the polymer matrix and the quantum dots in a weight ratio of 70:30 to 99:1.

(b) photopolymerizable monomer

In the quantum dot composition, the photopolymerizable monomer is a component forming a formulation in which quantum dots (QDs) are dispersed, that is, a polymer matrix, and serves to express the structure and physical properties of the matrix by controlling the overall crosslinking density of the polymer matrix.

In the present invention, the photopolymerizable monomer is a monomer having a carbon-carbon unsaturated bond at the terminal, specifically, a carbon-carbon double bond or a carbon-carbon triple bond at the terminal, and more specifically, a (meth)acrylate group, an acryl It may have at least one of a royl group, a methacryloyl group, an aryl group, and a vinyl group.

According to one example, the photopolymerizable monomer may have a (meth)acrylate group at its terminal. The (meth)acrylate monomer is a monofunctional acrylic monomer (f = 1), a bifunctional acrylic monomer (f = 2), It can be classified into a trifunctional acrylate monomer (f = 3) and a tetrafunctional or higher polyfunctional acrylate monomer (f ≥ 4).

In the present invention, a mixture of a bifunctional (meth)acrylate monomer, a trifunctional (meth)acrylate monomer, and a tetrafunctional or higher functional (meth)acrylate monomer is used as the photopolymerizable monomer.

In the present invention, bifunctional (meth)acrylate monomers and trifunctional (meth)acrylate monomers are referred to as 'low functional (meth)acrylate monomers'.

In addition, by including a polyfunctional (meth)acrylate monomer containing at least 4 polymerizable functional groups, due to the large number of functional groups included in the molecule, a more dense and dense three-dimensional network crosslinked structure is formed, thereby increasing the crosslinking density and The glass transition temperature (Tg) improvement effect can be realized.

In the quantum dot composition of the present invention, the content of the bifunctional (meth)acrylate monomer and the trifunctional (meth)acrylate monomer, which are low-functionality (meth)acrylate monomers, is 50 to 70 parts by weight based on 100 parts by weight of the total amount of the quantum dot composition. It may be part by weight.

Examples of the bifunctional (meth)acrylate monomer usable in the present invention include ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, polyolefin glycol di(meth)acrylate, ethoxylated polypropylene glycol di(meth)acrylate, meth)acrylate, 2-hydroxy-3-acryloyloxypropyl methacrylate, 2-hydroxy-1,3-dimethacryloxypropane, dioxane glycol di(meth)acrylate, tricyclodecanedi Methanol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, glycerin di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate )Acrylate, 1,10-decanediol di(meth)acrylate, neopentylglycol di(meth)acrylate, 2-methyl-1,8-octanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, butylethylpropanediol di(meth)acrylate, 3-methyl-1,5-pentanediol di(meth)acrylate and the like; di(meth)acrylates having an aromatic ring, such as ethoxylated bisphenol A di(meth)acrylate, propoxylated ethoxylated bisphenol A di(meth)acrylate, ethoxylated bisphenol F di(meth)acrylate, etc. There is, but is not limited to. According to one example, the difunctional (meth)acrylate monomer may be 1,6-hexanediol diacrylate.

The bifunctional (meth)acrylate monomer may be included in 20 to 40 parts by weight based on 100 parts by weight of the total amount of the composition. The physical properties of the quantum dot composition can be controlled by changing the content of the bifunctional (meth)acrylate monomer within an appropriate range. In particular, there is a part that lowers the viscosity of the entire composition, which is advantageous in terms of processability, and the coating property on the film is also excellent. When the content of the trifunctional or higher polyfunctional (meth)acrylate monomer is increased, the brittleness of the quantum dot-containing layer after curing increases, so that it is easily broken or curing shrinkage increases, resulting in severe curling of the film. Therefore, it is important to mix and use an appropriate amount of a bifunctional (meth)acrylate monomer.

Examples of trifunctional (meth)acrylate monomers usable in the present invention include ethoxylated glycerin tri(meth)acrylate, trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxy trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, and the like. According to one example, the trifunctional (meth)acrylate monomer may be trimethylolpropane triacrylate.

The weight average molecular weight (Mw) of these bifunctional (meth)acrylate monomers and trifunctional (meth)acrylate monomers may be about 100 g/mol or more, specifically 100 to 600 g/mol.

As the multifunctional (meth)acrylate monomer, known (meth)acrylate monomers containing 4 or more, specifically 4 to 6 photopolymerizable unsaturated groups in the molecule may be used without limitation. According to one example, the multifunctional (meth)acrylate monomer may include at least one of a tetrafunctional (meth)acrylate monomer and a 5-functional (meth)acrylate monomer, specifically a tetrafunctional (meth)acrylate monomer can be

Non-limiting examples of the multifunctional (meth)acrylate monomers usable in the present invention include pentaerythritol tetra(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, and ethoxylated pentaerythritol tetra(meth)acrylate. tetrafunctional (meth)acrylate monomers such as acrylate; Pentafunctional (meth)acrylate monomers such as dipentaerythritol pentaacrylate, propionic acid-modified dipentaerythritol pentaacrylate, dipentaerythritol pentamethacrylate, propionic acid-modified dipentaerythritol pentamethacrylate, and the like; Hexafunctional (meth)acrylate monomers such as dipentaerythritol hexaacrylate, caprolactone-modified dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, caprolactone-modified dipentaerythritol hexamethacrylate, etc. there is According to one example, the multifunctional (meth)acrylate monomer may be a tetrafunctional (meth)acrylate monomer, specifically ditrimethylolpropane tetra(meth)acrylate.

The weight average molecular weight (Mw) of this multifunctional (meth)acrylate monomer may be about 300 g/mol or more, specifically 300 to 1,000 g/mol.

The content of the multifunctional (meth)acrylate monomer in the photopolymerizable monomer may be 10 to 35 parts by weight based on 100 parts by weight of the total amount of the quantum dot composition. When the content of the multifunctional (meth)acrylic monomer falls within the above range, the viscosity and crosslinking density of the quantum dot composition are appropriately adjusted to improve the crosslinking structure and density of the matrix and improve the glass transition temperature (Tg). .

According to one embodiment of the present invention, the mixing ratio of the bifunctional (meth)acrylate monomer and the trifunctional (meth)acrylate monomer and the multifunctional (meth)acrylate monomer may be in a weight ratio of 55:45 to 90:10 there is.

In addition, the photopolymerizable monomer of the present invention is a carboxylic acid vinyl ester compound such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, 3-butenoic acid, vinyl acetate, vinyl benzoate; alkenyl aromatic compounds such as styrene, alpha-methyl styrene, vinyl toluene, and vinyl benzyl methyl ether; vinyl cyanide compounds such as acrylonitrile and methacrylonitrile; One or more kinds of unsaturated amide compounds such as acrylamide and methacrylamide may be included. These monomers may be used alone or in combination with the aforementioned (meth)acrylate monomers.

(c) light diffuser

In the quantum dot composition according to the present invention, the light diffusing agent reflects light that is not absorbed by the quantum dots and causes the quantum dots to absorb the reflected light again, thereby increasing the amount of light absorbed by the quantum dots to increase the light conversion efficiency of the composition. play a role in On the other hand, since the light diffusing agent increases the refractive index and turbidity of the composition, there is a problem in that optical properties are deteriorated by reducing the content of quantum dots included in order to realize the same color coordinates.

In order to solve this problem, the present invention seeks to set the optimal refractive index, optimize the quantum dot content, maximize optical properties, and reduce costs by adjusting the type and content of the light diffusing agent.

Specifically, in the present invention, a light diffusing agent selected from the group consisting of zinc oxide, titanium dioxide, and mixtures thereof is used.

When the present inventors use other oxidizing agent particles, such as calcium carbonate particles or silica particles, instead of zinc oxide and titanium dioxide particles as the light diffusing agent, the scattering effect, which is the original role of the light diffusing agent, is greatly reduced, so that the optical properties are greatly reduced. It was confirmed that product application itself became impossible (see Tables 1 and 2).

In addition, in the present invention, the content of the light diffusing agent may be 0.1 to 10 parts by weight based on 100 parts by weight of the total amount of the quantum dot composition.

For example, when using zinc oxide as a light diffusing agent, the content of zinc oxide is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the total amount of the quantum dot composition. If the content of zinc oxide is less than 0.1 parts by weight, the refractive index decreases due to the small content of the diffusing agent, and the content of quantum dots included to realize the same color coordinates becomes too large, which may increase manufacturing cost. If it exceeds 10 parts by weight, the refractive index increases In order to implement the same color coordinates, the amount of quantum dots included may decrease, resulting in a low luminance problem (see Table 1).

In another example, when titanium dioxide is used as a light diffusing agent, the content of titanium dioxide is preferably 0.1 to 5 parts by weight based on 100 parts by weight of the total amount of the quantum dot composition. If the content of titanium dioxide is less than 0.1 part by weight, the refractive index decreases due to the small content of the diffusion agent, so the content of quantum dots included to realize the same color coordinates becomes too large, which may increase the manufacturing cost. In order to implement the same color coordinates, the amount of quantum dots included may decrease, resulting in a low luminance problem (see Table 1).

As another example, when a mixture of zinc oxide and titanium dioxide is used as a light diffusing agent, the content of zinc oxide and titanium dioxide is preferably 0.1 to 10 parts by weight based on 100 parts by weight of the quantum dot composition. More preferably, the content of the mixture of zinc oxide and titanium dioxide may be 1 to 2 parts by weight based on 100 parts by weight of the total amount of the quantum dot composition. In this case, it is preferable that the content of zinc oxide is greater than the content of titanium dioxide. If the content of titanium dioxide is higher than that of zinc oxide, the luminance may decrease (see Table 2). Specifically, the mixing ratio of zinc oxide and titanium dioxide may be in a weight ratio of 0.7:0.3 to 1.9:0.1.

(d) an initiator

The quantum dot composition according to the present invention may further include an initiator, if necessary. The initiator is not particularly limited as long as it can generate radicals in the art, and includes, for example, a photoinitiator or a thermal initiator.

According to one example, the quantum dot composition of the present invention may further include at least one selected from the group consisting of a photoinitiator and a thermal initiator.

The photoinitiator is a component that serves to initiate photopolymerization by being excited by a light source such as ultraviolet (UV) light, and a conventional photopolymerization photoinitiator in the art may be used without limitation. For example, an acetophenone-based compound, a benzophenone-based compound, a thioxanthone-based compound, a benzoin-based compound, a triazine-based compound, an oxime-based compound, and the like may be used.

Non-limiting examples of usable photoinitiators include Irgacure 184, Irgacure 369, Irgacure 651, Irgacure 819, Irgacure 907, benzionalkylether, benzophenone, benzyldimethylkatal, hydroxyl Hydroxycyclohexyl phenylacetone, Chloroacetophenone, 1,1-Dichloroacetophenone, Diethoxy acetophenone, Hydroxyacetophenone Hydroxy Acetophenone, 2-Choro thioxanthone, 2-ETAQ (2-EthylAnthraquinone), 1-Hydroxy-cyclohexyl-phenyl-ketone , 2-hydroxy-2-methyl-1-phenyl-1-propanone, 2-hydroxy-1-[4-(2-hydroxy-2-methyl-1-phenyl-1-propanone) Roxyethoxy)phenyl]-2-methyl-1-propanone (2-Hydroxy-1-[4-(2-hydroxyethoxy)phenyl]-2-methyl-1-propanone), methylbenzoylformate, etc. These may be used alone or in combination of two or more.

The thermal initiator initiates polymerization by generating radicals by a predetermined amount of heat, and conventional thermal polymerization initiators known in the art may be used without limitation.

The thermal initiator may have a use temperature of about 35 °C or higher, specifically about 35 to 100 °C. In the case of using a thermal initiator having such an operating temperature, thermal curing may proceed simultaneously due to heat generated during photocuring by irradiation with ultraviolet rays. Therefore, the curing reaction of the composition can be sufficiently performed even to the light-shielding portion (shaded area, shaded area) through which ultraviolet rays cannot be transmitted without additional heating.

Thermal initiators available in the present invention include azo-based compounds, peroxide-based compounds, hydroperoxide-based compounds, hydrazide-based compounds, imidazole-based compounds, and/or radicals under heating conditions. Other thermal initiator(s) capable of releasing , and combinations thereof may be included. Specifically, there are azonitrile, azo ester, azo amide, organic peroxide, inorganic peroxide, organic hydroperoxide, inorganic hydroperoxide, or mixtures thereof.

Specific examples include benzoyl peroxide, di-t-amyl peroxide, t-butyl peroxy benzoate, di-cumyl peroxide, t-amyl hydroperoxide and t-butyl hydroperoxide, 2,5-dimethyl- 2,5-Di-(t-butylperoxy)hexyne-3) [2,5-Di(tert-butylperoxy)-2,5-dimethyl-3-hexyne], 2,5-dimethyl-2,5 -Di-(tert-butylperoxy)hexane [2,5-Bis(tert-butylperoxy)-2,5-dimethylhexane], a VAZO compound from DuPont [e.g., VAZO 52 (2,2') -Azobis (2,4-dimethylpentanenitrile)), Vazo 64 (2,2'-azobis (2-methylpropanenitrile)), Vazo 67 (2,2'-azobis (2-methylbutanenitrile)) )), Vazo 88 (2,2'-azobis (cyclohexanecarbonitrile)), etc.], but are not limited thereto.

The content of the initiator may be appropriately adjusted within a range known in the art. For example, it may be 0.1 to 5 parts by weight based on the total weight of the quantum dot composition. When the content of the initiator falls within the aforementioned range, photopolymerization can be sufficiently performed without deterioration of physical properties of the matrix.

(e) Optionally, the quantum dot composition according to the present invention includes at least one additive known in the art (eg, solvent, dispersant, etc.) within a range that does not affect the physical properties of the composition, in addition to the above-mentioned components, without limitation. can include more. In this case, the content of the additive may be appropriately adjusted within a range known in the art.

According to one embodiment of the present invention, the quantum dot composition may have a refractive index of 1.510 to 1.555.

Quantum dot composition according to the present invention, quantum dots; a photopolymerizable monomer including a bifunctional (meth)acrylate monomer, a trifunctional (meth)acrylate monomer, and a tetrafunctional or higher functional (meth)acrylate monomer; And it may be prepared by mixing and stirring a light diffusing agent selected from the group consisting of zinc oxide, titanium dioxide, and mixtures thereof according to a conventional method known in the art.

<Quantum dot optical film>

According to one embodiment of the present invention, a quantum dot optical film including a photocured material of the above-described quantum dot composition, that is, a quantum dot-containing layer is provided.

1 is a cross-sectional view schematically showing a quantum dot optical film according to a first embodiment of the present invention, and FIG. 2 is a cross-sectional view schematically showing a quantum dot optical film according to a second embodiment of the present invention.

As shown in FIGS. 1 and 2 , the quantum dot optical films 100A and 100B of the present invention include a base film 110; and a polymer matrix 121 disposed on one surface of the base film 110, and a plurality of quantum dots 122 and a light diffusing agent 123 dispersed in the polymer matrix 121. It may include a quantum dot-containing layer 120 and optionally further include a second base film 130 disposed on the quantum dot-containing layer 120 .

Hereinafter, referring to FIG. 1 , a quantum dot optical film 100A according to a first embodiment of the present invention will be described. However, descriptions overlapping with the above-described quantum dot composition will be omitted.

(1) Base film

In the quantum dot optical film 100A of the present invention, the base film 110 is a light-transmitting film, and can prevent the quantum dot-containing layer from being contaminated by foreign substances in the external environment while supporting the quantum dot-containing layer.

As the base film 110 usable in the present invention, any conventional light-transmitting film known in the art may be used without limitation. According to one example, the light-transmitting film may have a light transmittance of about 85 to 100%, specifically about 90% to 99% at a wavelength of 550 nm.

Examples of materials for the light-transmitting film include polyesters such as polyethylene naphthalate, polycarbonate, cycloolefin polymer, and polyethylene terephthalate (PET); Examples include polyolefin, polysulfone, polyimide, silicone, polystyrene, polyacryl, and polyvinylchloride, but are not limited thereto. These may be used alone or in combination of two or more.

The base film 110 may be a single layer or a multi-layered structure in which two or more resin films are laminated.

The thickness of the base film 110 is not particularly limited and can be appropriately adjusted within a typical thickness range used in the display field. For example, it may be about 10 to 200 μm.

(2) quantum dot-containing layer

In the quantum dot optical film 100A of the present invention, the quantum dot-containing layer 120 is disposed on one surface of the base film 110 and includes a photocured material of the above-described quantum dot composition.

Specifically, the quantum dot-containing layer 120 includes a polymer matrix 121 and a plurality of quantum dots 122 and a light diffusing agent 123 dispersed in the polymer matrix 121 .

Here, the description of the quantum dot 122 is omitted because it is the same as that described for the quantum dot in the above-described quantum dot composition.

The polymer matrix 121 impregnates a plurality of quantum dots 122 . That is, the plurality of quantum dot particles 122 may be scattered in the polymer matrix 121, or some of the quantum dot particles 122 may be disposed on the surface of the matrix.

The polymer matrix 121 includes the rest of the photocured material of the above-described quantum dot composition except for the quantum dots. Specifically, the polymer matrix 121 includes a photopolymerizable monomer including a bifunctional (meth)acrylate monomer, a trifunctional (meth)acrylate monomer, and a tetra- or higher functional (meth)acrylate monomer; and a light diffusing agent 123 selected from the group consisting of zinc oxide, titanium dioxide, and mixtures thereof.

In this case, the content of the bifunctional (meth)acrylate monomer and the trifunctional (meth)acrylate monomer may be 50 to 70 parts by weight based on 100 parts by weight of the quantum dot-containing layer. The bifunctional (meth)acrylate monomer and the trifunctional (meth)acrylate monomer may have a weight average molecular weight (Mw) of about 100 to 600 g/mol, and the multifunctional (meth)acrylate monomer may have about 300 It may be a tetrafunctional or higher functional (meth)acrylate monomer (specifically, a tetrafunctional (meth)acrylate monomer) having a weight average molecular weight (Mw) of ~ 1000 g/mol. The use ratio (mixing ratio) of the bifunctional (meth)acrylate monomer and the trifunctional (meth)acrylate monomer and the tetrafunctional or higher functional (meth)acrylate monomer may be 55:45 to 90:10 by weight. .

20 to 40 parts by weight of the bifunctional (meth)acrylate monomer may be included based on 100 parts by weight of the quantum dot-containing layer. The physical properties of the quantum dot composition can be controlled by changing the content of the bifunctional (meth)acrylate monomer within an appropriate range. In particular, there is a part that lowers the viscosity of the entire composition, which is advantageous in terms of processability, and the coating property on the film is also excellent. When the content of the trifunctional or higher polyfunctional (meth)acrylate monomer is increased, the brittleness of the quantum dot-containing layer after curing increases, so that it is easily broken or curing shrinkage increases, resulting in severe curling of the film. Therefore, it is important to mix and use an appropriate amount of a bifunctional (meth)acrylate monomer.

The multifunctional (meth)acrylate monomer may be included in an amount of 10 to 35 parts by weight based on 100 parts by weight of the quantum dot-containing layer. When the content of the multifunctional (meth)acrylic monomer falls within the above range, the viscosity and crosslinking density of the quantum dot composition are appropriately adjusted to improve the crosslinking structure and density of the matrix and improve the glass transition temperature (Tg). .

Since the description of the photopolymerizable monomer including the bifunctional (meth)acrylate monomer, the trifunctional (meth)acrylate monomer, and the tetrafunctional or higher functional (meth)acrylate monomer is the same as that described in the quantum dot composition section, , to be omitted.

According to one embodiment of the present invention, the zinc oxide may include 0.1 to 10 parts by weight based on 100 parts by weight of the quantum dot-containing layer.

According to another embodiment of the present invention, the titanium dioxide may include 0.1 to 5 parts by weight based on 100 parts by weight of the quantum dot-containing layer.

According to another embodiment of the present invention, the mixture of zinc oxide and titanium dioxide may include 0.1 to 10 parts by weight based on 100 parts by weight of the quantum dot-containing layer.

Since the description of the light diffusing agent selected from the group consisting of zinc oxide, titanium dioxide, and mixtures thereof is the same as that described in the quantum dot composition, it will be omitted.

According to one embodiment of the present invention, the photocurable composition may have a refractive index of 1.510 to 1.555.

In the quantum dot-containing layer 120, the use ratio of the polymer matrix 121 and the plurality of quantum dots 122 may be appropriately adjusted within a normal range known in the art. For example, the polymer matrix 121 and the plurality of quantum dots 122 may be included in a weight ratio of 70:30 to 99:1.

The thickness of the quantum dot-containing layer 120 is not particularly limited, but if the thickness of the quantum dot-containing layer is too thick, problems may occur during application (assembly) to a display, and if the thickness is too thin, a constant A entanglement phenomenon may occur due to lack of a gap, or the surface of the quantum dots 122 may be exposed and the barrier properties of the film may be deteriorated. Accordingly, the quantum dot-containing layer 120 may have a thickness of about 20 nm to about 100 μm.

Hereinafter, the quantum dot optical film 100B according to the second embodiment of the present invention shown in FIG. 2 will be described.

As shown in FIG. 2 , the quantum dot optical film 100B of the present invention includes a first base film 110; It is disposed on one surface of the first base film 110, and includes a polymer matrix 121, and a plurality of quantum dots 122 and a light diffusing agent 123 dispersed in the polymer matrix 121. a quantum dot-containing layer 120; and a second base film 130 disposed on the quantum dot-containing layer 120 .

Since the first base film 110 and quantum dot-containing layer 120 usable in the present invention are the same as those described in the base film and quantum dot-containing layer section of the first embodiment, they are omitted.

In the present invention, the second base film 130 is a light-transmitting film and is disposed opposite to the first base film 110 . That is, the second base film 130 interposes the quantum dot-containing layer 120 between the first base film and the second base film.

This second base film 130 is the same as or different from the first base film 110 . Description of examples, thickness, etc. of the second base film 130 usable in the present invention is the same as that described in the base film portion of the first embodiment, so it will be omitted.

The quantum dot optical film (100A, 100B) of the present invention configured as described above includes a bifunctional (meth)acrylate monomer, a trifunctional (meth)acrylate monomer, and a tetrafunctional or higher multifunctional (meth)acrylate monomer. and a quantum dot-containing layer 120 comprising a polymer matrix by mixing a light diffusing agent selected from the group consisting of zinc oxide, titanium dioxide, and mixtures thereof, together with a photopolymerizable monomer to be used. Thus, since the quantum dot-containing layer of the present invention has a dense and dense three-dimensional network cross-linked structure and includes a light diffusing agent selected from the group consisting of zinc oxide, titanium dioxide, and mixtures thereof, optimal refractive index setting, quantum dot content Optimization and maximization of optical properties are possible, as well as cost reduction effects (see Tables 1 and 2 below).

Meanwhile, in the present invention, the embodiment of FIGS. 1 and 2 described above is exemplarily described. However, it is also within the scope of the present invention to freely select and configure the number of layers constituting the quantum dot optical films 100A and 100B and the stacking order thereof according to the purpose. For example, a multi-layered structure may be obtained by changing the order of each of the layers 110, 120, and 130 or by introducing other layers common in the art.

Hereinafter, a method for manufacturing the quantum dot optical films 100A and 100B according to the present invention will be described. However, it is not limited only by the following manufacturing method, and each process step may be modified or optionally mixed as needed.

The manufacturing method of the quantum dot optical film (100A) according to the present invention is (i) quantum dots; a photopolymerizable monomer including a bifunctional (meth)acrylate monomer, a trifunctional (meth)acrylate monomer, and a tetrafunctional or higher functional (meth)acrylate monomer; A light diffusing agent selected from the group consisting of zinc oxide, titanium dioxide, and mixtures thereof; optionally at least one barrier material selected from the group consisting of halogen compounds and oxygen scavengers; Optionally preparing a quantum dot composition including a photoinitiator ('step S10'); and (ii) applying the quantum dot composition on one surface of the base film and curing the composition ('step S20'). Optionally, before curing the composition, a second base film may be placed in contact with the coated surface of the composition. However, the manufacturing method according to the present invention described above may be performed by modifying or selectively mixing the steps of each process as necessary.

In the step (i), a specific example of the quantum dot composition is based on 100 parts by weight of the total amount of the quantum dot and the photopolymerizable monomer, about 1 to 14 parts by weight of the quantum dots; About 50 to 70 parts by weight of a bifunctional (meth)acrylate monomer and a trifunctional (meth)acrylate monomer; and about 10 to 35 parts by weight of a polyfunctional (meth)acrylate monomer, and about 0 to 8 parts by weight (specifically, 0.1 to 1.5 parts by weight) of a halogen based on 100 parts by weight, which is the total amount of the quantum dot and the photopolymerizable monomer. compound and greater than about 0 to 8 parts by weight of an oxygen scavenger.

In step (ii), the quantum dot composition is applied on one surface of the first barrier film. At this time, the coating method is not particularly limited, and methods such as spray coating, roll coating, knife coating, spin coating, bar coating, flow coating, and dipping coating may be applied without limitation.

After such coating, by photocuring the applied composition, a desired quantum dot optical film can be prepared. At this time, photocuring conditions are not particularly limited and may be appropriately adjusted within a range known in the art.

Optionally, prior to photocuring of the composition, photocuring may be performed after the composition coating layer formation surface of the base film and one surface of the second base film are coupled to each other by arranging to face each other. If necessary, it may be bonded to have a certain thickness through a roll lamination process.

The quantum dot optical films 100A and 100B of the present invention configured as described above may be mounted on various display devices requiring quantum dots (QDs). For example, a quantum dot optical film of such a display device; a light source unit including a light source generating light; and a light guide plate guiding the light. Here, the backlight unit may further include an optical member and a reflective sheet.

For another embodiment of the present invention, a display device including the above-described backlight unit is provided. The display may include a display panel and a backlight unit, and the display panel may be a liquid crystal display panel, an electrophoretic display panel, or an electrowetting display panel. In addition, as the configuration of the display device, those known in the art may be applied.

Hereinafter, the present invention will be described in more detail through examples. However, the following examples are only for exemplifying the present invention, and the scope of the present invention is not limited to the examples.

<Example 1>

1-1. Preparation of photocurable composition

Based on 100 parts by weight of the quantum dot composition, trimethylolpropane triacrylate (M300, Miwon Specialty Chemical) 30 parts by weight and 3 parts by weight of zinc oxide as a light diffusing agent were added and dispersed, followed by hexanediol diacrylate (M200, Miwon Specialty Chemical) 30 25 parts by weight of ditrimethylolpropane tetraacrylate (M410, Miwon Specialty Chemical) were mixed to form a photoreactive polymer mixture, and quantum dots [green quantum dots (InP): red quantum dots (Inp) = 2: 1 weight ratio] 10 A photocurable composition was prepared by dispersing parts by weight on the photoreactive polymer mixture.

1-2. Manufacture of quantum dot optical films

The photocurable composition obtained in Example 1-1 was coated to a thickness of 85 μm on one surface of a polyethylene terephthalate film (thickness: 98 μm) as a base film, and then UV light amount of 80 mJ / cm 2 for 4 seconds A quantum dot optical film was prepared by irradiating light while curing to form a quantum dot-containing layer.

<Example 2>

2-1. Preparation of photocurable composition

A photocurable composition was prepared in the same manner as in Example 1-1, except that 1 part by weight of zinc oxide, 13.6 parts by weight of the quantum dot mixture, and 28.4 parts by weight of hexanediol diacrylate were used.

2-2. Manufacture of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 2-1 was used instead of the photocurable composition used in Example 1-2.

<Example 3>

3-1. Preparation of photocurable composition

A photocurable composition was prepared in the same manner as in Example 1-1, except that 2 parts by weight of zinc oxide and 11 parts by weight of the quantum dot mixture were used.

3-2. Manufacture of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 3-1 was used instead of the photocurable composition used in Example 1-2.

<Example 4>

4-1. Preparation of photocurable composition

A photocurable composition was prepared in the same manner as in Example 1-1, except that 6 parts by weight of zinc oxide, 8.1 parts by weight of the quantum dot mixture, and 28.9 parts by weight of hexanediol diacrylate were used.

4-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 4-1 was used instead of the photocurable composition used in Example 1-2.

<Example 5>

5-1. Preparation of photocurable composition

A photocurable composition was prepared in the same manner as in Example 1-1, except that 8 parts by weight of zinc oxide, 7.2 parts by weight of the quantum dot mixture, and 27.8 parts by weight of hexanediol diacrylate were used.

5-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 5-1 was used instead of the photocurable composition used in Example 1-2.

<Example 6>

6-1. Preparation of photocurable composition

A photocurable composition was prepared in the same manner as in Example 1-1, except that 10 parts by weight of zinc oxide, 7 parts by weight of the quantum dot mixture, and 26 parts by weight of hexanediol diacrylate were used.

6-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 6-1 was used instead of the photocurable composition used in Example 1-2.

<Example 7>

7-1. Preparation of photocurable composition

A photocurable composition was prepared in the same manner as in Example 1-1, except for using 1 part by weight of titanium dioxide, 9.9 parts by weight of a quantum dot mixture, and 32.1 parts by weight of hexanediol diacrylate instead of zinc oxide.

7-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 7-1 was used instead of the photocurable composition used in Example 1-2.

<Example 8>

8-1. Preparation of photocurable composition

A photocurable composition was prepared in the same manner as in Example 1-1, except for using 2 parts by weight of titanium dioxide, 8.6 parts by weight of a quantum dot mixture, and 32.4 parts by weight of hexanediol diacrylate instead of zinc oxide.

8-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 8-1 was used instead of the photocurable composition used in Example 1-2.

<Example 9>

9-1. Preparation of photocurable composition

A photocurable composition was prepared in the same manner as in Example 1-1, except for using 3 parts by weight of titanium dioxide, 7.4 parts by weight of a quantum dot mixture, and 32.6 parts by weight of hexanediol diacrylate instead of zinc oxide.

9-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 9-1 was used instead of the photocurable composition used in Example 1-2.

<Comparative Example 1>

1-1. Preparation of photocurable composition

A photocurable composition was prepared in the same manner as in Example 1-1, except that 3 parts by weight of calcium carbonate, 16.8 parts by weight of the quantum dot mixture, and 23.2 parts by weight of hexanediol diacrylate were used instead of zinc oxide.

1-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Comparative Example 1-1 was used instead of the photocurable composition used in Example 1-2.

<Comparative Example 2>

2-1. Preparation of photocurable composition

A photocurable composition was prepared in the same manner as in Example 1-1, except that 3 parts by weight of silicon dioxide, 16 parts by weight of the quantum dot mixture, and 24 parts by weight of hexanediol diacrylate were used instead of zinc oxide.

2-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Comparative Example 1-1 was used instead of the photocurable composition used in Example 1-2.

<Experimental Example 1>

In order to confirm the optical properties of the quantum dot optical sheet according to the content of zinc oxide and titanium dioxide of the light diffusing agent, the following measurements were performed and the measurement results are shown in Table 1 below.

The refractive index of the photocurable compositions of Examples 1 to 9 and Comparative Examples 1 to 2 was measured using a refractometer (ATAGO DTM-N), and the measurement results are shown in Table 1 below.

The luminance (Lm) and color coordinates (Cx, Cy) of the quantum dot optical films of Examples 1 to 9 and Comparative Examples 1 to 2 were measured using an integrating sphere (PIMACS, Neolight IS500), and then Luminance was calculated and expressed according to Equation 1 below. At this time, the luminance (Lm) of Example 1 to which 3 parts by weight of ZnO was applied was set to 100%.

(In the above formula,

Lm ₁ is the luminance value of the quantum dot optical film of Example 1,

Lm ₂ is the luminance value of the quantum dot optical films of Examples 2 to 9 and Comparative Examples 1 to 2).

In Table 1 below, quantum dot content and luminance change were set to 100% respectively for the quantum dot content and luminance of Example 1.

Example 1 Example
2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Comparative Example 1 Comparative Example 2 Diffusion agent content 3 parts by weight of ZnO ZnO 1 part by weight 2 parts by weight of ZnO 6 parts by weight of ZnO ZnO 8 parts by weight 10 parts by weight of ZnO TiO ₂ 1 part by weight TiO ₂ 2 parts by weight TiO ₂ 3 parts by weight CaCO ₃ 3 parts by weight SiO ₂ 3 parts by weight quantum dot content 10 parts by weight 13.6 parts by weight 11 parts by weight 8.1 parts by weight 7.2 parts by weight 7 parts by weight 9.9 parts by weight 8.6 parts by weight 7.4 parts by weight 16.8 parts by weight 16 parts by weight Quantum dot content compared to Example 1 100% 136% 110% 81% 72% 70% 99% 86% 74% 168% 160% M200 content 30 parts by weight 28.4 parts by weight 30 parts by weight 28.9 parts by weight 27.8 parts by weight 26 parts by weight 32.1 parts by weight 32.4 parts by weight 32.6 parts by weight 23.2 parts by weight 24 parts by weight refractive index 1.521 1.511 1.516 1.535 1.545 1.555 1.518 1.530 1.542 1.479 1.478 luminance 593 615 601 567 556 532 576 549 517 563 581 luminance change 100% 104% 101% 96% 94% 90% 97% 93% 87% 95% 98% Cx 0.233 0.233 0.233 0.232 0.232 0.232 0.233 0.233 0.232 0.233 0.233 Cy 0.186 0.186 0.185 0.185 0.186 0.186 0.186 0.185 0.185 0.184 0.184

As shown in Table 1, the refractive indices of the optical films of Example 2 and Example 3, in which the zinc oxide content was 1 part by weight and 2 parts by weight, respectively, were 1.511 and 1.516, respectively, which were lower than 1.521 in Example 1, and had the same color coordinates. The content and luminance of the quantum dots included to implement the increased. In particular, the optical film of Example 2 had the best optical properties with a 4% increase in luminance compared to Example 1, but a 36% increase in quantum dot content, resulting in an increase in manufacturing cost.

In addition, in Examples 4, 5, and 6 in which the zinc oxide content was 6 parts by weight, 8 parts by weight, and 10 parts by weight, respectively, the refractive index was increased compared to Example 1. In order to realize the same color coordinates, included quantum dots and luminance were reduced. In particular, the refractive index of the optical film of Example 6 was significantly increased to 1.555 compared to Example 1, and the content of quantum dots included in the optical film was reduced to 70% to realize the same color coordinates, so the luminance was reduced to 90%.

In addition, in Examples 7, 8, and 9 using titanium dioxide instead of zinc oxide, the refractive index increased as the content of titanium dioxide increased, whereas the content of quantum dots included to implement the same color coordinates decreased. In particular, the refractive index increased when compared to Examples 1 to 3 using zinc oxide based on the same content, but the amount of quantum dots decreased and the luminance decreased.

On the other hand, in Comparative Example 1 and Comparative Example 2, calcium carbonate or silicon dioxide was applied instead of zinc oxide, and the total refractive index of the photocurable composition was reduced to 1.479 and 1.478, respectively, and as the refractive index decreased, the number of quantum dots to realize the same color coordinates The content was increased by 68% and 60%, respectively, compared to Example 1, and the luminance was decreased by 5% and 2%, respectively.

Through the above results, the quantum dot optical film of the present invention using zinc oxide and titanium dioxide as light diffusing agents can not only improve optical properties in the same color coordinates, but also reduce the content of quantum dots to enable cost reduction. know that it can.

<Example 10>

10-1. Preparation of photocurable composition

Photocurability was performed in the same manner as in Example 1-1, except that 0.9 parts by weight of zinc oxide and 0.3 parts by weight of titanium dioxide were simultaneously used as light diffusing agents, and 11.2 parts by weight of the quantum dot mixture and 30.6 parts by weight of hexanediol diacrylate were used. A composition was prepared.

10-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 10-1 was used instead of the photocurable composition used in Example 1-2.

<Example 11>

11-1. Preparation of photocurable composition

0.9 parts by weight of zinc oxide and 0.1 part by weight of titanium dioxide were simultaneously used as light diffusing agents, and 12.3 parts by weight of the quantum dot mixture and 29.7 parts by weight of hexanediol diacrylate were used, but photocurability was performed in the same manner as in Example 1-1. A composition was prepared.

3-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 11-1 was used instead of the photocurable composition used in Example 1-2.

<Example 12>

12-1. Preparation of photocurable composition

Photocurability was performed in the same manner as in Example 1-1, except that 0.7 parts by weight of zinc oxide and 0.3 parts by weight of titanium dioxide were simultaneously used as light diffusing agents, and 11.2 parts by weight of the quantum dot mixture and 30.8 parts by weight of hexanediol diacrylate were used. A composition was prepared.

12-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 12-1 was used instead of the photocurable composition used in Example 1-2.

<Example 13>

13-1. Preparation of photocurable composition

0.5 parts by weight of zinc oxide and 0.5 parts by weight of titanium dioxide were simultaneously used as light diffusing agents, and 11 parts by weight of the quantum dot mixture and 31 parts by weight of hexanediol diacrylate were used, but photocurability was performed in the same manner as in Example 1-1. A composition was prepared.

13-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 13-1 was used instead of the photocurable composition used in Example 1-2.

<Example 14>

14-1. Preparation of photocurable composition

0.3 parts by weight of zinc oxide and 0.7 parts by weight of titanium dioxide were simultaneously used as light diffusing agents, and 11 parts by weight of the quantum dot mixture and 31 parts by weight of hexanediol diacrylate were used, but photocurability was performed in the same manner as in Example 14-1. A composition was prepared.

14-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 14-1 was used instead of the photocurable composition used in Example 1-2.

<Example 15>

15-1. Preparation of photocurable composition

Photocurability was performed in the same manner as in Example 1-1, except that 0.2 parts by weight of zinc oxide and 0.8 parts by weight of titanium dioxide were simultaneously used as light diffusing agents, and 10.3 parts by weight of the quantum dot mixture and 31.7 parts by weight of hexanediol diacrylate were used. A composition was prepared.

15-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 15-1 was used instead of the photocurable composition used in Example 1-2.

<Example 16>

16-1. Preparation of photocurable composition

0.1 part by weight of zinc oxide and 0.9 part by weight of titanium dioxide were simultaneously used as the light diffusing agent, and 10.3 parts by weight of the quantum dot mixture and 31.7 parts by weight of hexanediol diacrylate were used, but photocurability was performed in the same manner as in Example 1-1. A composition was prepared.

16-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 16-1 was used instead of the photocurable composition used in Example 1-2.

<Example 17>

17-1. Preparation of photocurable composition

1.9 parts by weight of zinc oxide and 0.1 part by weight of titanium dioxide were simultaneously used as the light diffusing agent, and 10.3 parts by weight of the quantum dot mixture and 30.7 parts by weight of hexanediol diacrylate were used, but photocurability was performed in the same manner as in Example 1-1. A composition was prepared.

17-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 17-1 was used instead of the photocurable composition used in Example 1-2.

<Example 18>

18-1. Preparation of photocurable composition

1.7 parts by weight of zinc oxide and 0.3 part by weight of titanium dioxide were simultaneously used as the light diffusing agent, and 9.9 parts by weight of the quantum dot mixture and 31.1 parts by weight of hexanediol diacrylate were used, but photocurability was performed in the same manner as in Example 1-1. A composition was prepared.

18-2. Fabrication of quantum dot optical films

A quantum dot optical film was prepared in the same manner as in Example 1-2, except that the photocurable composition prepared in Example 18-1 was used instead of the photocurable composition used in Example 1-2.

<Experimental Example 2>

In order to confirm the optical properties of the quantum dot optical sheet according to the simultaneous application of the light diffusing agent zinc oxide and titanium dioxide and the change in ratio, the measurement results are shown in Table 2 below after measuring as follows.

The refractive indices of the quantum dot optical films of Examples 10 to 18 and Comparative Examples 1 to 2 were measured using a refractometer (ATAGO DTM-N), and the measurement results are shown in Table 2 below.

The luminance (Lm) and color coordinates (Cx, Cy) of the quantum dot optical films of Examples 10 to 18 and Comparative Examples 1 to 2 were measured using an integrating sphere (PIMACS, Neolight IS500), and then the luminance change compared to Example 1 Is calculated according to Equation 1 and is shown in Table 2 below.

In Table 2 below, quantum dot content and luminance change were set to 100% respectively for the quantum dot content and luminance of Example 1.

Example 10 Example 11 Example 12 Example 13 Example 14 Example 15 Example 16 Example 17 Example 18 Comparative Example 1 Comparative Example 2 Diffusion agent content ZnO 0.9 parts by weight ZnO 0.9 parts by weight ZnO 0.7 parts by weight ZnO 0.5 parts by weight ZnO 0.3 parts by weight ZnO 0.2 parts by weight ZnO 0.1 part by weight ZnO 1.9 parts by weight ZnO 1.7 parts by weight CaCO ₃ 3 parts by weight SiO ₂ 3 parts by weight TiO ₂ 0.3 parts by weight TiO ₂ 0.1 part by weight TiO ₂ 0.3 parts by weight TiO ₂ 0.5 parts by weight TiO ₂ 0.7 parts by weight TiO ₂ 0.8 parts by weight TiO ₂ 0.9 parts by weight TiO ₂ 0.1 part by weight TiO ₂ 0.3 parts by weight Quantum dot content 11.2 parts by weight 12.3 parts by weight 11.2 parts by weight 11 parts by weight 11 parts by weight 10.3 parts by weight 10.3 parts by weight 10.3 parts by weight 9.9 parts by weight 16.8 parts by weight 16.0 parts by weight Quantum dot content compared to Example 1 112% 123% 112% 110% 110% 103% 103% 103% 99% 168% 160% M200 content 30.6 parts by weight 29.7 parts by weight 30.8 parts by weight 31 parts by weight 31 parts by weight 31.7 parts by weight 31.7 parts by weight 30.7 parts by weight 31.1 parts by weight 23.2 parts by weight 24 parts by weight refractive index 1.514 1.512 1.513 1.515 1.516 1.517 1.518 1.517 1.518 1.479 1.478 luminance 598 611 597 583 577 587 589 601 591 563 581 luminance change 101% 103% 101% 98% 97% 99% 99% 101% 100% 95% 98% Cx 0.233 0.233 0.232 0.236 0.235 0.233 0.234 0.232 0.234 0.233 0.233 Cy 0.183 0.183 0.184 0.185 0.184 0.183 0.186 0.184 0.184 0.184 0.184

As shown in Table 2, the optical film of Example 11 has excellent optical properties with a 3% increase in luminance compared to the optical film of Example 1, but a 23% increase in quantum dot content, and a 23% increase in luminance compared to the optical film of Example 2. was reduced by 1%, but the quantum dot content was reduced by 13%.

In particular, as the content of zinc oxide decreased and the content of titanium dioxide increased in Examples 14 to 16, the refractive index increased and the content of quantum dots decreased. As a result, the luminance was reduced to 97~99% under the same color coordinate conditions.

In addition, in the optical film of Example 17, the content of quantum dots increased by 3% compared to the optical film of Example 1, but the luminance increased by 1%.

In addition, in the optical film of Example 18, as the content of zinc oxide increased to 1.7% and the content of titanium dioxide decreased to 0.3%, the content of quantum dots decreased by 1%, and luminance was maintained.

Through the above results, the quantum dot optical film of the present invention using a mixture of zinc oxide and titanium dioxide as a light diffusing agent can not only improve optical properties in the same color coordinates, but also reduce the content of quantum dots to enable cost reduction. know you can do it.

100A, 100B: quantum dot optical film,
110: base film, first base film,
120: quantum dot containing layer,
121: polymer matrix,
122: quantum dot,
123: light diffusing agent,
130: second base film

Claims (18)

base film; and
disposed on the base film, and a polymer matrix; and a quantum dot-containing layer comprising a plurality of quantum dots dispersed in the polymer matrix.
including,
The polymer matrix may include a photopolymerizable monomer including a bifunctional (meth)acrylate monomer, a trifunctional (meth)acrylate monomer, and a tetrafunctional or higher functional (meth)acrylate monomer; and
Including a cured product of a photocurable composition including a light diffusing agent composed of a mixture of zinc oxide and titanium dioxide,
The bifunctional (meth)acrylate monomer and the trifunctional (meth)acrylate monomer and the tetrafunctional or higher functional (meth)acrylate monomer are included in a weight ratio of 55:45 to 90:10,
The mixture of zinc oxide and titanium dioxide is mixed in a weight ratio of 0.7: 0.3 to 1.9: 0.1,
The quantum dot-containing layer comprises the polymer matrix and the plurality of quantum dots in a weight ratio of 70 to 99: 1 to 30, the quantum dot optical film. delete delete According to claim 1,
The bifunctional (meth) acrylate monomer is contained in 20 to 40 parts by weight based on 100 parts by weight of the quantum dot-containing layer, the quantum dot optical film. According to claim 1,
The bifunctional (meth) acrylate monomer and the trifunctional (meth) acrylate monomer having a weight average molecular weight (Mw) of 100 to 600 g / mol, the quantum dot optical film. According to claim 1,
The multifunctional (meth) acrylate monomer has a weight average molecular weight (Mw) of 300 to 1000 g / mol, the quantum dot optical film. According to claim 1,
The zinc oxide is contained in 0.1 to 10 parts by weight based on 100 parts by weight of the quantum dot-containing layer, the quantum dot optical film. According to claim 1,
The titanium dioxide is contained in 0.1 to 5 parts by weight based on 100 parts by weight of the quantum dot-containing layer, the quantum dot optical film. According to claim 1,
The mixture of zinc oxide and titanium dioxide is contained in 0.1 to 10 parts by weight based on 100 parts by weight of the quantum dot-containing layer, the quantum dot optical film. According to claim 1,
The photocurable composition has a refractive index of 1.510 to 1.555, the quantum dot optical film. quantum dots;
photopolymerizable monomers including a bifunctional (meth)acrylate monomer, a trifunctional (meth)acrylate monomer, and a tetrafunctional or higher functional (meth)acrylate monomer; and
A light diffusing agent made of a mixture of zinc oxide and titanium dioxide,
The bifunctional (meth)acrylate monomer and the trifunctional (meth)acrylate monomer and the tetrafunctional or higher functional (meth)acrylate monomer are included in a weight ratio of 55:45 to 90:10,
The mixture of zinc oxide and titanium dioxide is mixed in a weight ratio of 0.7:0.3 to 1.9:0.1,
The quantum dot comprises 1 to 14 parts by weight based on 100 parts by weight of the total amount of the composition,
Quantum dot composition. delete delete According to claim 11,
The bifunctional (meth) acrylate monomer is contained in 25 to 35 parts by weight based on 100 parts by weight of the total amount of the composition, the quantum dot composition. According to claim 11,
The zinc oxide is contained in 0.1 to 10 parts by weight based on 100 parts by weight of the total amount of the composition, the quantum dot composition. According to claim 11,
The titanium dioxide is contained in 0.1 to 5 parts by weight based on 100 parts by weight of the total amount of the composition, the quantum dot composition. According to claim 11,
The mixture of zinc oxide and titanium dioxide is contained in 0.1 to 10 parts by weight based on 100 parts by weight of the total amount of the composition, the quantum dot composition. According to claim 11,
The quantum dot composition has a refractive index of 1.510 to 1.555, the quantum dot composition.

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