KR20190007069A - An adhesive composition for a quantum dot sheet and a quantum dot sheet thereof, and a backlight unit and a display device - Google Patents

Abstract

The adhesive composition for a quantum dot sheet according to the present invention is excellent in optical properties and adhesive force, quantum dot and light scattering agent can be easily and stably dispersed, and low viscosity, The quantum dot sheet applied to the backlight unit is economical and has excellent brightness and uniformity, low color deviation, adhesion, and stability over time, and when applied to a backlight unit, exhibits color reproducibility substantially equivalent to that of amorphous.

Description

An adhesive composition for a quantum dot sheet and a quantum dot sheet thereof, and a backlight unit and a display device

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an adhesive composition for a quantum dot sheet for imparting low moisture permeability used for producing a quantum dot sheet for a display, a quantum dot sheet produced thereby, a backlight unit (BLU) An adhesive composition for a quantum dot sheet in which a barrier property for preventing moisture permeability is maximized in a quantum dot dispersing adhesive (binder resin), and a quantum dot sheet having excellent economical efficiency in which the necessity of using a barrier film is eliminated by using the adhesive composition , A backlight unit (BLU) including the barrier film, and a display device. The present invention relates to a backlight unit (BLU) including the barrier film, Quantum dot sheet cost savings of more than 50% It is.

Highly reproducible display technology is the closest to the essence of display to achieve 'sharp picture quality'. Currently, AMOLED and Quantum dot (QD) display technologies are examples of technologies that can realize such a high reproducibility display.

The application of the photoluminescence (PL) characteristics of the quantum dots has the advantage of using existing LED process technology as a backlight unit (BLU) module application technology of existing LED display. Particularly, in case of color reproducibility, if the color reproduction rate of the conventional display is about 70% based on the National Television System Committee (NTSC) standard, the color reproduction rate of the quantum dot display can be improved to 110%, which is similar to that of OLED. In the case of power consumption, quantum dots have higher luminous efficiency than OLEDs and thus have very low power consumption. When quantum dots are applied to BLU, instead of white LEDs using all three primary colors of RGB, white can be achieved with only blue LEDs with high energy efficiency.

Methods for implementing such a QD-display can be classified into a QD-Package type, a QD-Rail type, and a QD-Film / Sheet type. First, the QD-Package type is a QD-package type that directly mounts a quantum dot directly on an LCD package. However, since the structure is simple, deterioration due to the influence of LED heat generation, compatibility with LED encapsulation resin, It has not been released. Second, QD-Rail is the on-edge method applied to the edge type LED BLU. It has the smallest QD consumption, mass production, and low manufacturing cost. It is suitable for LCD display, but color reproducibility is lower than AMOLED. Third, the QD-sheet is an on-surface method in which quantum dots are formed as a film and placed on a light guide plate of a blue BLU module. That is, this means that a quantum dot is dispersed in a binder resin (adhesive) to form a sheet, and a quantum dot sheet wrapped with two barrier films / sheets is disposed on the light guide plate. Because it is a thin film, it can be applied without changing the size, thickness and structure even in a small LCD panel, and it is easy to apply the existing process because there is no big difference from the LCD module process. It also has the advantage of being able to realize various screens from small size to large size. And it plays a role of suppressing the moisture and oxygen deterioration of the quantum dots through the barrier film / sheet among the materials constituting the quantum dot sheet. Currently, 3M (USA) of USA is developed and commercialized by NANOSIS (USA) and commercialized as QDEF ^® (Quantum Dot Enhancement Film ^® ).

The quantum dot sheet material composition largely consists of a base film / sheet, a barrier film / sheet, a quantum dot (QD), light scattering agents, and an adhesive / binder resin. The barrier film / sheet and the quantum dot account for more than 90% of the total material cost, and the double barrier film / sheet is the quantum dot / Account for about 50% of the total material cost of the sheet. Therefore, lowering the prices of quantum dots and barrier films / sheets is an important factor in determining the price competitiveness of quantum dot sheet products.

Therefore, it is a first object of the present invention to provide a method for producing a quantum dot sheet using a non-barrier film (that is, a base film excluding the use of a barrier film) having a very excellent price competitiveness as compared with a quantum dot sheet using an existing barrier film And to provide an adhesive composition for a quantum dot sheet which imparts low moisture permeability.

A second object of the present invention is to provide an adhesive composition for a quantum dot sheet which is excellent in optical characteristics and adhesive force, and has a low water vapor permeability with a viscosity at room temperature of 50 to 1,000 cps, which facilitates coating workability.

A third object of the present invention is to provide an adhesive composition for a quantum dot sheet which is easy to disperse quantum dots and a light scattering agent and is excellent in dispersibility and dispersion stability.

A fourth object of the present invention is to provide a quantum dot sheet having excellent brightness, uniformity, adhesion, and very low color deviation, which is processed by using the above-described adhesive composition for a quantum dot sheet and a non-barrier film.

In addition, a fifth object of the present invention is to provide a method for accelerating the life span of 500 hours in a constant temperature and humidity chamber at a temperature of 60 degrees and a relative humidity of 90%, which is a reliability evaluation standard manufactured using the adhesive composition for a quantum dot sheet and the non- And is excellent in reliability with excellent brightness, uniformity, adhesive force and very low color deviation even after the light is advanced.

In addition, a sixth object of the present invention is to provide a backlight unit having an excellent color reproducibility including the above-described quantum dot sheet.

A seventh object of the present invention is to provide a display device including the aforementioned backlight unit.

The first to third objects of the present invention are as follows: 10 to 30% by weight of a polyfunctional (meth) acrylate polymer represented by the following general formula (1), 10 to 60% by weight of a urethane acrylate oligomer of the following general formula By weight and a photoinitiator in an amount of 0.1 to 10% by weight based on the total weight of the composition.

(Formula 1)

(In the general formula 1 R ₁ is hydrogen (H-) or methyl (CH ₃ - a), R ₂ is a hydrophobic straight chain hydrocarbon groups, branched hydrocarbon groups, cycloaliphatic hydrocarbon group, an aromatic group, an alkyl or aromatic group, R ₃ is a hydrophilic hydroxyl groups (-OH), a hydroxyl hydrocarbon groups, a carboxyl group (-COOH), a carboxyl hydrocarbon group, an amine group (-NH _2), a hydrocarbon group, a polyethylene glycol, or polypropylene glycol containing an amino group, R ₄ An aromatic group or an alkylaromatic group having a Tg value of at least 80 degrees, and n, m and l are each independently an integer of 0 or more, and 100? N + m +

(2)

(In the formula R ₁ 2 is hydrogen (H-) or methyl (CH ₃ - a), and, R ₂ is a straight-chain hydrocarbon groups, branched hydrocarbon groups, cycloaliphatic hydrocarbon group, an aromatic group, an alkyl or aromatic group, R ₃ is Propylene oxide adduct type bisphenol group, dehydrogenated bisphenol group, ethylene oxide adduct type dehydrogenated bisphenol group, or propylene oxide adduct type dehydrogenated bisphenol group, and m is an integer of 1 or more Lt; = m < = 100).

The adhesive composition for a quantum dot sheet according to the present invention may further comprise 10 to 60% by weight of a modified epoxy oligomer represented by the following formula (3).

(Formula 3)

(Wherein R ₁ is hydrogen (H-) or methyl group (CH ₃ -) and n is an integer of 0 or more, and 0? N?

The fourth and fifth objects of the present invention are to provide a quantum dot sheet adhesive composition comprising a quantum dot sheet adhesive composition in which quantum dot nanoparticles and light scattering agent nano or microparticles are dispersed and applied to an optical film or sheet, . ≪ / RTI >

The sixth object of the present invention can be achieved by a backlight unit (BLU) including a quantum dot sheet to which the above-described non-barrier optical sheet is applied.

The seventh object of the present invention can be achieved by a liquid crystal display device including the aforementioned backlight unit.

The adhesive composition for a quantum dot sheet according to the present invention which has low moisture permeability has extremely excellent optical properties and adhesion and can easily disperse the quantum dots and the light scattering agent and can keep their dispersion stability excellent, The uniform coating operation can be performed very easily on one surface of the non-barrier sheet (film) at a viscosity of 50 to 3,000 cps.

The adhesive composition for a quantum dot sheet and the quantum dot sheet produced by using a non-barrier sheet, which have low moisture permeability, have excellent brightness and uniformity and low color deviation, have excellent adhesion between films, Condition: temperature 60 ° C, relative humidity 90%, 500 hours), and it is possible to provide excellent price competitiveness compared to a conventional quantum dot sheet using a barrier film.

In addition, the backlight unit including the above-described quantum dot sheet and the display device including the backlight unit can have almost the same color reproducibility as the amorphous.

Best Mode for Carrying Out the Invention

The adhesive composition for a quantum dot sheet according to the present invention comprises 10 to 30% by weight of a polyfunctional (meth) acrylate polymer represented by the following formula (1), 10 to 60% by weight of a urethane acrylate oligomer of the following formula 10 to 60 wt%, and 0.1 to 10 wt% of a photoinitiator.

(Formula 1)

(In the general formula 1 R ₁ is hydrogen (H-) or methyl (CH ₃ - a), R ₂ is a hydrophobic straight chain hydrocarbon groups, branched hydrocarbon groups, cycloaliphatic hydrocarbon group, an aromatic group, an alkyl or aromatic group, R ₃ is a hydrophilic hydroxyl groups (-OH), a hydroxyl hydrocarbon groups, a carboxyl group (-COOH), a carboxyl hydrocarbon group, an amine group (-NH _2), a hydrocarbon group, a polyethylene glycol, or polypropylene glycol containing an amino group, R ₄ An aromatic group or an alkylaromatic group having a Tg value of at least 80 degrees, and n, m and l are each independently an integer of 0 or more, and 100? N + m +

(2)

(In the formula R ₁ 2 is hydrogen (H-) or methyl (CH ₃ - a), and, R ₂ is a straight-chain hydrocarbon groups, branched hydrocarbon groups, cycloaliphatic hydrocarbon group, an aromatic group, an alkyl or aromatic group, R ₃ is Propylene oxide adduct type bisphenol group, dehydrogenated bisphenol group, ethylene oxide adduct type dehydrogenated bisphenol group, or propylene oxide adduct type dehydrogenated bisphenol group, and m is an integer of 1 or more Lt; = m < = 100).

The adhesive composition for a quantum dot sheet according to the present invention may further comprise 10 to 60% by weight of a modified epoxy oligomer represented by the following formula (3).

(Formula 3)

(Wherein R ₁ is hydrogen (H-) or methyl group (CH ₃ -) and n is an integer of 0 or more, and 0? N?

A quantum dot sheet according to the present invention is obtained by applying a quantum dot sheet adhesive composition in which quantum dot nanoparticles and light scattering agent nano- or microparticles are dispersed to an optical film or sheet,

Further, a backlight unit (BLU) according to the present invention includes a quantum dot sheet to which the above-described non-barrier optical sheet is applied.

Further, the liquid crystal display device according to the present invention includes the above-described backlight unit.

DETAILED DESCRIPTION OF THE INVENTION

Hereinafter, the present invention will be described in detail.

The adhesive composition for a quantum dot sheet according to the present invention comprises a polyfunctional (meth) acrylate polymer of the following formula (1), a urethane acrylate oligomer of the following formula (2), an acrylate monomer and a photoinitiator, May include a modified epoxy oligomer of the following formula (3).

(Formula 1)

(In the general formula 1 R ₁ is hydrogen (H-) or methyl (CH ₃ - a), R ₂ is a hydrophobic straight chain hydrocarbon groups, branched hydrocarbon groups, cycloaliphatic hydrocarbon group, an aromatic group, an alkyl or aromatic group, R ₃ is a hydrophilic hydroxyl groups (-OH), a hydroxyl hydrocarbon groups, a carboxyl group (-COOH), a carboxyl hydrocarbon group, an amine group (-NH _2), a hydrocarbon group, a polyethylene glycol, or polypropylene glycol containing an amino group, R ₄ An aromatic group or an alkylaromatic group having a Tg value of at least 80 degrees, and n, m and l are each independently an integer of 0 or more, and 100? N + m +

(2)

(In the formula R ₁ 2 is hydrogen (H-) or methyl (CH ₃ - a), and, R ₂ is a straight-chain hydrocarbon groups, branched hydrocarbon groups, cycloaliphatic hydrocarbon group, an aromatic group, an alkyl or aromatic group, R ₃ is Propylene oxide adduct type bisphenol group, dehydrogenated bisphenol group, ethylene oxide adduct type dehydrogenated bisphenol group, or propylene oxide adduct type dehydrogenated bisphenol group, and m is an integer of 1 or more Lt; = m < = 100).

(Formula 3)

(Wherein R ₁ is hydrogen (H-) or methyl group (CH ₃ -) and n is an integer of 0 or more, and 0? N?

The multifunctional (meth) acrylate polymer represented by Formula 1 may preferably be a multifunctional (meth) acrylate having a refractive index of 1.40 to 1.55 and a molecular weight of 10,000 to 100,000.

Also, the polyfunctional (meth) acrylate polymer represented by Formula 1 is preferably contained in an amount of 10 to 30% by weight based on the total weight of the adhesive composition. When the addition amount of the polyfunctional (meth) acrylate polymer represented by the above formula (1) is less than 10% by weight on the basis of the above-mentioned criteria, the light transmittance and brightness are lowered, color coordinate defects are generated, color deviation is increased, It is undesirable because defects may occur in the reliability evaluation. Conversely, if it exceeds 30% by weight, the viscosity becomes excessively high, which may cause problems in workability.

The urethane acrylate oligomer compound represented by Formula 2 is preferably contained in an amount of 10 to 60% by weight based on the total weight of the adhesive composition. When the addition amount of the urethane acrylate oligomer compound represented by the formula (2) is less than 10% by weight on the basis of the above-mentioned criteria, color coordinate defects occur, color deviation increases, adherence deteriorates, If the content is more than 60% by weight, it is also undesirable because it may cause yellowing, decrease in light transmittance and brightness, deterioration in adhesion, and viscosity, which may cause problems in workability.

In the present invention, the urethane acrylate oligomer may preferably be a urethane acrylate oligomer having a refractive index of 1.40 to 1.55 and a molecular weight of 500 to 10,000.

The urethane acrylate oligomer may be specifically selected from aliphatic urethane oligomers, aromatic urethane acrylate oligomers, polyester acrylate oligomers, epoxy acrylate oligomers, or any mixture thereof.

The modified epoxy oligomer compound represented by Formula 3 is preferably contained in an amount of 10 to 60% by weight based on the total weight of the adhesive composition. When the amount of the modified epoxy oligomer compound represented by the above formula (3) is less than 10% by weight based on the above-mentioned criteria, color coordinate defects are generated, color deviation becomes large, adherence is markedly deteriorated, On the other hand, if it exceeds 60% by weight, the decrease of the luminance and the viscosity become too high, which may cause problems in workability.

The modified epoxy oligomer represented by Formula 3 may be an epoxy acrylate oligomer having a refractive index of 1.40 to 1.55 and a molecular weight of 500 to 8,000.

In the present invention, the acrylate monomer can control the viscosity of the adhesive composition, increase the adhesive force, and maintain excellent brightness and light transmittance.

More preferably, the acrylate monomer is a low-viscosity acrylate monomer having a viscosity at 25 ° C of 1 to 200 cps.

The acrylate monomer is preferably contained in an amount of 10 to 60% by weight based on the total weight of the composition. If the addition amount of the monofunctional acrylate monomer is less than 10% by weight based on the above-mentioned criteria, the optical characteristics of the composition may be lowered and the viscosity may be so high that the workability may deteriorate. Conversely, There is a possibility that the adhesive force with the substrate deteriorates.

The acrylate monomers specifically include tetrahydrofuryl acrylate (THFA), tetrahydrofuryl methacrylate (THFMA), cyclic trimethylol propane foam acrylate (CTFA), 3,3,5-trimethyl cyclohexyl acrylate (TMMA), isobornyl acrylate (IBOA), isobornyl methacrylate (IBOMA), methyl methacrylate (MMA), methyl acrylate (MA), methacrylic acid (MAA), ethyl methacrylate Ethyl acrylate (EA), n-butyl methacrylate (BMA), isobutyl methacrylate (IBMA), t-butyl methacrylate (TBMA), 2-ethylhexyl acrylate (2- (2-ethylhexyl methacrylate), lauryl acrylate (LA), lauryl (EO) ₂ acrylate (LA (EO) ₂ A), isooctyl acrylate (IOA), isooctyl methacrylate IOMA), isodecyl acrylate (IDA), isodecyl methacrylate (IDMA), teth (2-hydroxyethyl acrylate, 2-hydroxyethyl acrylate, 2-ethylhexyl acrylate, 2-ethylhexyl acrylate) ), 2-hydroxymethacrylate (2-HEMA), 2-hydroxypropyl acrylate (2-HPA), 2-hydroxypropylmethacrylate (2-HPMA), 2-hydroxybutyl acrylate 2-HBA), 2-hydroxybutyl methacrylate (2-HBMA), 2-hydroxy-3-phenoxypropyl acrylate (HPPA), caprolactone acrylate (CPLA), 2-carboxyethyl acrylate (EO) acrylate (EO) A, maleic acid (EO) methacrylate (MA (EO) MA), phthalic acid (EO) ), Phthalic acid (EO) methacrylate (PA (EO) MA), succinic acid (EO) acrylate (SA (EO) A), succinic acid (EO) Ethyl acrylate (2-CEA), ethoxyethoxyethyl acrylate (EOEOEA ), Glycidyl methacrylate (GMA), ethoxy triethylene glycol methacrylate (ETEGMA), polyethylene glycol monoacrylate (PEGMA), polyethylene glycol monomethacrylate (PEGMMA), polyalkylene glycol monomethacrylate (PAGMMA), polypropylene glycol monomethacrylate (PPGMMA), N, N-dimethylacrylamide (DMAA), acrylonylmorpholine (ACMO), N- vinyl-2-pyrrolidone rate (BZA), benzyl methacrylate (BZMA), phenoxyethyl acrylate (PHEA), phenoxy (EO) ₂ acrylate _{(PH (EO) 2 A)} , phenoxy (EO) ₄ acrylate (PH ( EO) ₄ A), nonylphenoxy (EO) ₄ acrylate _{(NPH (EO) 4 A)} , nonylphenoxy (EO) ₈ acrylate _{(NPH (EO) 8 A)} , nonylphenoxy (PO) ₂ acrylic (POE) ₂ A, phenoxybenzyl acrylate (PBA), 4-cumyl phenoxy ethyl acrylate (CPEA), O-phenyl phenoxy ethyl acrylate (OPPEA), O-phenyl phenoxy ) ₂ Acrylate (OPP (EO) ₂ A), 1,4-butanediol diacrylate (BDDA), 1,4-butanediol dimethacrylate (BDDMA), 1,6-hexanediol diacrylate , Hexanediol dimethacrylate (HDDMA), 1,10-decanediol diacrylate (DDDA), diethylene glycol diacrylate (DEGDA), triethylene glycol diacrylate (TEGDA), polyethylene glycol diacrylate (PEGDA), polyethylene glycol dimethacrylate (PEGDMA), dipropylene glycol diacrylate (DPGDA), tripropylene glycol diacrylate (TPGDA), polypropylene glycol diacrylate (PPGDA), polypropylene glycol dimethacrylate Acrylate (PPGDMA), neopentyl glycol diacrylate (NPGDA), cyclohexanedimethanol diacrylate (CHDMDA), dicyclodecane dimethanol diacrylate (DCDDMDA), bisphenol A diacrylate (BPADA) ethylene oxide addition type Derivatives, bisphenol A (BPADMA) ethylene oxide addition type derivatives, bisphenol fluorene diacrylate (BPFDA) ethylene oxide addition type derivatives, trimethylpropane triacrylate (TMPTA), trimethylpropane triacrylate (TMPTA) ethylene oxide addition type derivatives, trimethylpropane tri methacrylate (TMPTMA), trimethylol propane trimethyl acrylates (TMPTMA) ethylene oxide addition-type derivatives, pentaerythritol triacrylate (PETA), pentaerythritol tri methacrylate (PETMA), Glacier serine (PO) ₃ triacrylate (G (PO) ₃ TA), tri (2-hydroxyethyl) isoionate triacrylate (THEIC), tris-2-hydroxyethylisocyanurate triacrylate (THEITA), ditrimethylpropane tetraacryl (DTMPTA), pentaerythritol tetraacrylate (PETTA), pentaerythritol tetraacrylate (PE TTA) ethylene oxide adduct derivatives, dipentaerythritol pentaacrylate (DPPA), dipentaerythritol nuclear acrylate (DPHA), dipentaerythritol nuclear acylate (DPHA) ethylene oxide adduct derivatives, or any mixture thereof Can be used.

In the present invention, the photoinitiator is not particularly limited and any of those generally used in the art can be arbitrarily selected and used.

The photoinitiator may be a hydroxyketone photoinitiator, an amino ketone photoinitiator, a phenylglyoxylate photoinitiator, a benzyldimethylketal photoinitiator, a phosphine photoinitiator, or any mixture thereof.

More specifically, the photoinitiator is selected from the group consisting of 1-hydroxycyclohexyl phenyl ketone, benzophenone, 2-hydroxy-2-methyl- 2-phenyl-acetoxy-ethoxy] -ethyl ester and oxy-phenyl-acetic acid 2- [2-oxo- Alpha-dimethoxy-alpha-phenylacetophenone, 2-benzoyl-2- (dimethylamino) -1- [4- (4- (4-morpholinyl) phenyl] -1-butanone, 2-methyl-1- [4- Trimethylbenzoyl) -phosphine oxide, phosphine oxide phenylbis (2,4,6-trimethylbenzonyl), bis (eta 5-2,4-cyclopentadien-1-yl) bis [2,6 (1-) -difluoro-3- (1-etch-pyrrol-1-yl) phenyl] titanium, idonium (4-methylphenyl) Diphenyl ketone 4-hydroxycyclophenyl ketone, dimethoxy-2-phenylacetophenone, anthraquinone, fluorene, triphenylamine, carbazole, 3-methylacetophenone, 4-dimethoxyacetophenone, 4,4-diaminobenzophenone, or any mixture thereof may be appropriately selected and used.

The photoinitiator is preferably contained in an amount of 0.01 to 10% by weight based on the total weight of the composition. If the content of the photoinitiator is less than 0.01% by weight, the curing rate may be too slow, and if it is more than 10% by weight, yellowing may occur.

In the adhesive composition for a quantum dot sheet according to the present invention which imparts low moisture permeability, an additive may be optionally added as needed. The additive may be used in an amount of 0.001 to 5 wt%, based on the total weight of the composition, of an antioxidant, a UV absorber, a light stabilizer, a thermal polymerization inhibitor, a leveling agent, a surfactant, an antifouling agent or any mixture thereof , Which is not limiting and optional in the present invention. In particular, in order to provide UV stability of the quantum dot sheet, a UV absorber and a light stabilizer and a thermal polymerisation inhibitor may be added within the range not to impair the effect of the present invention in order to prevent thermal polymerization of the composition.

The adhesive composition for a quantum dot sheet having low moisture permeability according to the present invention preferably has a viscosity of 50 to 3,000 cps and a refractive index of 1.40 to 1.55. If the viscosity of the adhesive composition is less than 50 cps, the thickness of the adhesive layer in which the quantum dots and the light scattering agent are dispersed becomes too thin to cause problems in optical properties and adhesive strength. If the viscosity exceeds 3,000 cps, the viscosity becomes too high, . Further, when the refractive index is from 1.46 to 1.54, it is preferable since it can realize the most ideal optical characteristics.

In addition, the quantum dot nanoparticles and the light scattering agent nano and / or microparticles can be uniformly and stably dispersed in the adhesive composition according to the present invention to produce quantum dot sheets.

The quantum dot nanoparticles may be selected from the group consisting of CdSe, CdSe / ZnS, CdTe, CdTe / CdS, ZnSe / ZnS, ZnTe / ZnSe, PbSe, PbS, InP, InGaP, InGaP / ZnS, InAs, HeTe, Can be used.

Wherein the light scattering nano- and / or microparticles are selected from the group consisting of Al ₂ O ₃ , ZnO, SiO ₂ , ZrO ₂ , SnO ₂ , CeO ₂ , MgO, CaO, TiO ₂ , Y ₂ O ₃ , Sb ₂ O ₃ , BaTiO ₃ , Fe ₃ O ₄ , or any mixture thereof may be selected and used.

The present invention also provides a quantum dot sheet produced by applying an adhesive composition for a quantum dot sheet in which quantum dots and a light scattering agent are dispersed to one surface of an optical film / sheet,

In the present invention, the optical film / sheet substrate is not particularly limited but is preferably a transparent substrate made of transparent polyethylene terephthalate (PET), polymethylacrylate (PMMA), polycarbonate (PC) And can be coated on at least one side of both sides.

The thickness of the quantum dot and light scattering agent dispersion adhesive layer is in the range of 20 to 200 mu m, preferably 50 to 150 mu m, more preferably 70 to 100 mu m.

The adhesive composition in which the quantum dot and the light scattering agent are dispersed according to the present invention is instantly cured by irradiating UV light after application and the dose of UV light is about 0.01 to 2 J / cm ² , preferably 0.1 to 1 J / cm ² More preferably 0.2 to 0.7 J / cm ² , and the wavelength is preferably 365 nm as the main wavelength.

The adhesive composition in which the quantum dot and the light scattering agent are dispersed according to the present invention is prepared by using a non-barrier optical sheet having a moisture permeability (measurement standard: ASTM F1249) of 10 ^-1 g / m ² · day or more A quantum dot sheet can be produced.

The quantum dot sheet prepared using the adhesive composition in which the quantum dot and the light scattering agent are dispersed according to the present invention and the non-barrier optical sheet having a moisture permeability of 10 ^-1 g / m ² · day or more has excellent brightness and uniformity, , Adhesion between the films is very good, reliability standards can be satisfied even after the life acceleration test (experimental conditions: temperature 60 ° C, relative humidity 90%, 500 hours), and quantum dots using conventional barrier sheets It can give excellent price competitiveness compared to the seat.

The quantum dot sheet prepared as described above has a high productivity due to rapid application and curing of the adhesive composition during manufacture, and it is possible to control the thickness of the adhesive layer in which the quantum dots and the light scattering agent are dispersed.

The present invention also provides a backlight unit (BLU) having a quantum dot sheet using the non-barrier sheet.

The backlight unit is not limited and a structure known in the art may be employed. For example, a light source (CCFL or LED), a reflection sheet, a light guide panel (LGP), a diffusion sheet, a prism sheet, a protection sheet, and a quantum dot sheet ).

The backlight unit according to the present invention may be formed by applying the adhesive composition in which the quantum dots of the present invention and the light scattering agent are dispersed to one side of the above reflective plate, light guide plate, diffuser plate or prism sheet, A light guide plate, a diffuser plate, a prism sheet, and a quantum dot sheet can be formed into an integral type and inserted into the backlight unit.

The present invention also provides a liquid crystal display device comprising the adhesive composition in which the quantum dot and the light scattering agent are dispersed and the quantum dot sheet produced using the non-barrier optical sheet. Preferably, the liquid crystal display device may include the backlight unit having the quantum dot sheet according to the present invention.

In addition, the backlight unit including the above-described quantum dot sheet and the display device including the same have almost the same color reproducibility as AMOLED.

Hereinafter, the present invention will be described in more detail with reference to examples and comparative examples, but it should be understood that the present invention is not limited thereto.

Synthesis Example 1: Synthesis of copolymer polymer of triacryl monomer for quantum dot sheet adhesive

(1) Three kinds of acrylic monomer copolymer polymer design:

The design and synthesis of polymers through copolymerization of three acrylic monomers were carried out. Particularly, in the design of the copolymer structure, a monomer capable of imparting a hydrophobic group for imparting a low-moisture-permeability and a functional group for increasing a bonding force, and a high Tg (glass for imparting hardness) The glass transition temperature (Tg) of the monomer was selected and the polymerization reaction was carried out.

Scheme 1 below shows a synthesis scheme of a co-polymer of a trifunctional monomer having three different functional groups.

(Scheme 1)

Wherein R ₁ is hydrogen (H-) or methyl group (CH ₃ -), R ₂ is a hydrophobic straight chain hydrocarbon group, a branched chain hydrocarbon group, a cyclo hydrocarbon group, an aromatic group or an alkyl aromatic group and R ₃ is a hydrophilic hydroxyl groups (-OH), a hydroxyl hydrocarbon groups, a carboxyl group (-COOH), a carboxyl hydrocarbon group, an amine group (-NH _2), a hydrocarbon group, a polyethylene glycol, or polypropylene glycol containing an amino group, R ₄ An aromatic group or an alkyl aromatic group having a Tg value of at least 80 degrees in order to impart hardness to the copolymer to be synthesized, and n, m and l are each independently an integer of 0 or more and satisfy 100? N + m + l? 5,000.)

(2) Synthesis of three kinds of monomer copolymerized polymers:

(EHA), 2-carboxyethyl acrylate (CEA) and isobornyl acrylate (IBOA) in an equivalent ratio of 6: 3: 1 with a nitrogen tube and a thermometer attached to a 3-necked round flask The polymerization reaction was carried out at a selected temperature between 70 and 90 ° C. for 5 hours using an azobis or peroxide based compound as an initiator. In addition, nitrogen gas was introduced into the reactants to minimize side reactions due to oxygen radicals. In most reactions, the stirring speed was set to 200 rpm and the reaction proceeded. The polymer formed by the polymerization reaction was obtained as a high-viscosity transparent polymer solution (codename: P-EHCIA).

(3) Synthesis of three kinds of monomer copolymerized polymers:

As a result of GPC (Gel Permeation Chromatography) analysis to confirm the molecular weight and polydispersity index (PDI) values of the three polymers synthesized above, it was confirmed that the molecular weight was 53,000 MW and the PDI value was 1.25.

(4) Chemical structure of the code name P-EHCIA:

The following chemical formula 4 is a chemical structural formula of the above-mentioned code name P-EHCIA.

(Formula 4)

Synthesis Example 2: Synthesis of hydrocarbon-based urethane acrylate oligomer for quantum dot sheet adhesive

(1) A hydrocarbon-based urethane acrylate oligomer capable of imparting adhesion and fexibility to the quantum dot sheet adhesive composition was synthesized. In Step 1, the reaction was carried out for 2 hours using a catalyst at a temperature of 80 ° C at a reaction ratio of 1 equivalent of a 1000 molecular weight pulp propylene glycol (PPG 1000) and 2 equivalents of isophorone diisocyanate (IPDI). In Step 2, IPDI-PPG 1,000-IPDI and 2-HEA were reacted at a temperature of 100 ° C at a reaction ratio of 1 equivalent of the synthesized IPDI-PPG 1,000-IPDI and 2 equivalents of 2-hydroxyethyl acrylate (HEA) And reacted for 3 hours. Finally, a hydrocarbon-based urethane acrylate oligomer of HEA-IPDI-PPG 1,000-IPDI-HEA structure was obtained.

Scheme 2 below is a synthesis scheme for synthesis of a hydrocarbon-based urethane acrylate oligomer (codename: P-1000-IH).

(Scheme 2)

(2) Analysis of FT-IR and ¹ H-NMR spectra of the synthesized hydrocarbon-based urethane acrylate oligomer (HEA-IPDI-PPG 1,000-IPDI-HEA) revealed that the ketone group was formed, It was judged that all the reactions were completed.

^{1 H-NMR (ppm):} 5.8 ~ 6.4 (H 2 C = CH-), 3.2 ~ 4.5 (-CH 2 -CH 2 -), 1.0 ~ 1.2 (-CH 3)

Synthesis Example 3: Synthesis of epoxy urethane acrylate oligomer for quantum dot sheet adhesive

(1) An epoxy urethane acrylate oligomer for controlling the refractive index of the quantum dot sheet adhesive composition was synthesized. In Step 1, the reaction was carried out for 2 hours using a catalyst at a temperature of 80 ° C at a reaction ratio of 1 equivalent of propylene oxide (3) addition type bisphenol A and 2 equivalents of isophorone diisocyanate (IPDI). In Step 2, IPDI-bisphenol A (3) -IPDI was reacted with 1 equivalent of the synthesized IPDI-bisphenol A PO (3) -IPDI and 2 equivalents of 2-hydroxyethyl acrylate (2-HEA) Bisphenol A PO (3) -IPDI and 2-HEA were reacted for 3 hours. Finally, an epoxy urethane acrylate oligomer of HEA-IPDI-bisphenol A PO (3) -IPDI-HEA structure was obtained. Scheme 3 below is a synthesis scheme of an epoxy urethane acrylate oligomer (codename: PO3-BSA-IH).

(Scheme 3)

(2) The ¹ H-NMR spectrum of the epoxy urethane acrylate oligomer synthesized using propylene oxide-added bisphenol A alcohol (code name: PO3-BSA-IH) was analyzed.

^{1 H-NMR (ppm):} 6.8 ~ 7.2 (Ar H), 5.8 ~ 6.4 (H 2 C = CH-), 3.8 ~ 4.5 (-CH 2 -CH 2 -), 1.0 ~ 1.8 (-CH 3)

(3) Another type of epoxy urethane acrylate oligomer for controlling the refractive index of the quantum dot sheet adhesive composition was synthesized. In Step 1, the reaction was carried out for 2 hours using a catalyst at a temperature of 80 ° C at a reaction ratio of 1 equivalent of ethylene oxide (6) -added bisphenol A and 2 equivalents of isophorone diisocyanate (IPDI). In Step 2, IPDI-bisphenol A EO (6) -IPDI was reacted with 1 equivalent of the synthesized IPDI-bisphenol A EO (6) -IPDI and 2 equivalents of 2-hydroxyethyl acrylate (2-HEA) Bisphenol A EO (6) -IPDI and HEA were reacted for 3 hours. Finally, an epoxy urethane acrylate oligomer having an HEA-IPDI-bisphenol A EO (6) -IPDI-HEA structure was obtained (code name: EO6-BSA-IH).

(4) Analysis of ¹ H-NMR spectrum of an epoxy urethane acrylate oligomer (code name: EO6-BSA-IH) synthesized using an ethylene oxide added bisphenol A alcohol.

^{1 H-NMR (ppm):} 6.8 ~ 7.2 (Ar H), 5.8 ~ 6.4 (H 2 C = CH-), 3.6 ~ 4.5 (-CH 2 -CH 2 -), 1.0 ~ 1.8 (-CH 3)

Synthesis Example 4: Synthesis of dehydrogenated epoxy oligomer for quantum dot sheet adhesive

(1) Next, a dehydrogenated epoxy oligomer was prepared for controlling the light transmission ratio, adhesion and refractive index of the quantum dot sheet adhesive composition. The UV curable aliphatic epoxy acrylate was prepared by reacting a dehydrated bisphenol-based aliphatic epoxy resin with a monofunctional acrylic resin, 2-hydroxyethyl acrylate (2-HEA). First, 1 mol of dehydrogenated bisphenol-based aliphatic epoxy resin (molecular weight: 1,000) and 2 mol of 2-HEA were added to the reactor, followed by addition of a catalyst and heating and stirring at 80 ° C to completely dissolve the epoxy resin. Lt; / RTI > After the reaction, the mixture was cooled to room temperature to obtain a viscous, dehydrogenated epoxy oligomer (code: DHEA) as a transparent liquid. Scheme 4 below is a reaction scheme for the synthesis of a dehydrogenated epoxy oligomer (codename: DHEA).

(Scheme 4)

(2) dehydrogenation of aliphatic bisphenol-based epoxy resin with 2-hydroxyethyl acrylate The dehydrogenation epoxy oligomer synthesized in (2-HEA): Analysis of the FT-IR spectrum of (code name DHEA), 3,400 cm ^{- 1} appears a peak characteristic of the hydroxyl group in the vicinity, it was seen that the C = O peak of the ester carbonyl group of the acrylate represented newly formed in the vicinity of 1720 cm ^-1. Also at 1636 cm ^-1 and 1618 cm ^-1 C = C of acrylate, COC at 1188 cm ^-1 . Twisting vibration of = CH ₂ at 984 cm ^-1 appeared.

The ¹ H-NMR spectrum of the dehydrogenated epoxy oligomer (code name: DHEA) was also analyzed.

^{1 H-NMR (ppm):} 5.8 ~ 6.4 (H 2 C = CH-), 1.0 ~ 3.9 (-CH 2 -CH 2 -), 0.5 ~ 1.0 (-CH 3)

Synthesis Example 5: Synthesis of bifunctional epoxy monomer for quantum dot sheet adhesive

(1) A dehydrogenated epoxy bifunctional monomer for controlling the optical properties and adhesion of the quantum dot sheet adhesive composition was synthesized. Aliphatic epoxy acrylate was prepared by reacting a monomolecular type dehydrogenated bisphenol-based aliphatic epoxy resin with a monofunctional acrylic resin, 2-hydroxyethyl acrylate (2-HEA). The synthesis method was as follows . First, 1 mol of a monomolecular dehydrogenated bisphenol-based aliphatic epoxy resin and 2 mol of 2-HEA were added to the reactor, the catalyst was added, and the mixture was heated and stirred at 80 ° C to completely dissolve the epoxy resin. Lt; / RTI > After completion of the reaction, the mixture was cooled to room temperature to obtain a viscous, monomolecular, dehydrated epoxy bifunctional monomer (code name: MDHEA) having a transparent liquid. Reaction Scheme 5 below is a reaction scheme for the synthesis of monomolecular dehydrogenated epoxy bifunctional monomer (code name: MDHEA).

(Scheme 5)

(2) FT-IR spectrum of monomolecular type dehydrogenated bisphenol-based aliphatic epoxy resin and monomolecular type dehydrogenated epoxy bifunctional monomer (code name: MDHEA) synthesized with 2-hydroxyethyl acrylate (2-HEA) As a result, it was found that the characteristic peak of the hydroxyl group was observed at around 3400 cm ^-1 and the C═O peak of the ester carboxylate of the newly formed acrylate was observed at around 1721 cm ^-1 . Also at 1636 cm ^-1 and 1618 cm ^-1 C = C of acrylate, COC at 1188 cm ^-1 . A twisted vibration of = CH ₂ at 984 cm ^-1 appeared.

(3) ¹ H-NMR spectrum of monomolecular dehydrogenated epoxy bifunctional monomer (code name: MDHEA) was also analyzed.

¹ H-NMR (ppm) 5.8-6.4 (H ₂ C = CH-), 3.8-4.2 (-CH ₂ -CH ₂ -), 1.0-2.8 (Bisphenol H)

Method for evaluating physical properties and optical properties of adhesive composition for quantum dot sheet:

In order to evaluate the reliability of the adhesive, quantum dot sheet and BLU (module) for quantum dot sheets according to the present invention, the optical / chemical / physical properties of the material and parts are selected to determine the main performance of the final product along with the accelerated life test of the module Respectively. The following summarizes the physical / chemical evaluation items and evaluation methods of the adhesive for quantum dot sheets, namely specific gravity, viscosity, APHA color, refractive index, phase stability (high / low temperature stability, discoloration) The test conditions and method for evaluation of the moisture permeability, adhesive force, and optical property change according to the reliability evaluation, and the test purpose and the judgment criteria are summarized for the fabricated quantum dot sheet (parts).

(1) Specific gravity (Specific gravity, unit: -): ① The adhesive for the quantum dot sheet was injected into the density tester, and the temperature was elevated to 25 ° C (test conditions). ② After confirming the specific gravity of the sample measured by the density tester, the measured value was recorded (Test method: KS M ISO 12185).

(2) Viscosity measurement (Viscosity, unit: cps): The adhesive for a quantum dot sheet was put in a beaker and heated to 25 ° C (test conditions), and analyzed automatically using a Brookfield rotational viscometer. After confirming the viscosity of the sample measured by the viscometer, the measured value was recorded (test method: KS M ISO 2555).

(3) APHA Color Measurement (Chromaticity, Unit: degree): The adhesive for the quantum dot sheet was placed in a transparent container for chromaticity measurement, and analyzed automatically by a colorimeter at room temperature (23) After checking the chromaticity of the sample measured by the colorimeter, the measured value was recorded (see Test Specification: ISO 6271-2).

(4) Measurement of phase stability (high temperature / low temperature phase stability, discoloring property): A transparent glass container was loaded with an adhesive for a quantum dot sheet (sample) and placed in a constant temperature chamber at 0, 25, For 30 days. After 30 days, each sample was taken out from the thermostatic chamber and stored at room temperature for 12 hours. Then, the degree of delamination, discoloration, and curability was evaluated. For each sample, ① it is judged as "bad" if at least one of phase difference, discoloration, and uncured is found by checking whether or not there is any change in visibility (visual evaluation), discoloration (APHA color change) , And (2) when there was no abnormality on both sides, discoloration and uncured, it was judged as "excellent".

(5) Curing light quantity measurement (light quantity, temperature: room temperature, unit: mJ / cm ² ): An adhesive (sample) for a quantum dot sheet is coated on a non-barrier sheet, After lamination to the non-barrier sheet, UV was irradiated using a UV curing machine. At this time, the UV irradiation amount (light amount) of the photopolymerization was measured by a UV meter (UV Power Puck II & UVICURE, EIT) and the photocuring measurement value was recorded (KS M ISO 11507).

(6) Transmittance reduction (unit:%): A non-barrier sheet having a cured sample is coated with an adhesive (sample) for a quantum dot sheet on a non-barrier sheet, And the light transmittance was measured. The measured light transmittance value was converted to the light transmittance lowering value in terms of the light transmittance measured value and difference value of the non-barrier sheet to which the adhesive for quantum dot sheet was not applied. When the value calculated according to the following formula, [light transmittance lowering value (%) = (non-barrier sheet light transmittance value quantum dot sheet light transmittance value) / (non-barrier sheet light transmittance value) x 100] "Bad" was judged to be "good" if ② was less than 8.

(7) Coating thickness (unit: 占 퐉) of the quantum dot sheet: The cut quantum dot sheet was cut, and the cut surface was observed with a scanning electron microscope (SEM). The thickness of the coating layer in which the quantum dot was dispersed was measured, (KS M ISO 9220: 2009).

(8) Measurement of water vapor permeability (unit: g / m ² · day): After installing the selected non-barrier sheet (specimen) in MOCON ^® equipment, water permeation through the specimen is continuously carried out for 6 hours Were measured and recorded. The moisture permeability value was recorded at a point where there was little change in the measured value (after about 72 hours). The water vapor permeability measurement value of the non-barrier sheet used in the present invention was 2.86 x 10 ⁰ g / m ² · day, and the test result was written as "≥10 ^-1 g / m ² · day" (ASTM F 1249).

(9) Evaluation of Adhesive Force between Non-Barrier Film (T-Type Peel Strength, Peel Strength, kg / inch): After cutting the non-barrier sheet to a length of 200 mm and a width of 25 mm, The adhesive agent was applied 150 mm from one side and then the diffusion sheet specimen coated with the adhesive for the quantum dot sheet was cured by UV irradiation using a UV curing machine. The prepared specimens were placed in a peel strength tester and pulled at an angle of 90 degrees to measure the peel strength. The peel strength value was judged as "bad" when the adhesive strength was less than 10, and "excellent" when it was 10 or more (KS M ISO 11339).

(10) Measurement of Change in Optical Properties According to Reliability Evaluation (Measurement of Change in Brightness, Color Coordinates and Color Deviation According to Life Acceleration Test) A quantum dot sheet (specimen) made of a non-barrier sheet was heated at a temperature of 60 캜 and a relative humidity of 90 %, The measured value of luminance, chromaticity coordinate and chromaticity deviation of the specimen before and after the accelerated lifetime test was calculated to measure the luminance lowering value and the change value of the color coordinate and color deviation . That is, the luminance lowering value was calculated as [luminance lower value (%) = (luminance measured before lifetime acceleration experiment - luminance measured after lifetime acceleration test) / (luminance measured before lifetime acceleration experiment) x 100] The color variation value is calculated from the following equation: [Color Coordinates and Color Deviation Change Value (%) = (Color Coordinates / Color Deviation Measurement Value Before Life Acceleration Experiment - Color Coordinate / Color Deviation Measurement Value After Life Acceleration Experiment) / Value) x 100]. In the case of the luminance, the measured value after the evaluation with respect to the measured value before the reliability evaluation was judged to be "poor" when the value decreased by more than 15%, and "excellent" when it was less than 15%. In the case of chromaticity coordinates and color deviation, it was judged as "bad" when the measured value was changed by more than ① / 1000 compared with the measured value before reliability evaluation, and when it was changed to less than / 1000, it was judged as "excellent". Finally, the reliability evaluation results are as follows: (1) When the change values of the luminance, chromaticity coordinate and color deviation are within the reference value, the reliability evaluation result is judged as "excellent." , And "bad" (KS C IEC 61988-2-1: 2003).

Examples 1 to 20 and Comparative Examples 1 to 10

An adhesive composition for a quantum dot sheet was prepared by combining the respective components at the composition components and composition ratios shown in Tables 1 to 3 below to give a low moisture permeability, and the properties were evaluated according to the above evaluation method. .

P-EHCIA: copolymerized polymer of the three kinds of monomers synthesized in Synthesis Example 1

P-1000IH: The hydrocarbon-based urethane oligomer synthesized in Synthesis Example 2

PO3-BSA-IH: PO (3) addition type epoxy urethane oligomer synthesized in Synthesis Example 3

EO6-BSA-IH: EO (6) addition type epoxy urethane oligomer synthesized in Synthesis Example 3

DHEA: dehydrogenated epoxy oligomer synthesized in Synthesis Example 4

IBOA: isobornyl acrylate (monofunctional monomer)

2-EHA: 2-ethylhexyl acrylate (monofunctional monomer)

2-CEA: 2-carboxyethyl acrylate (monofunctional monomer)

2-HEA: 2-hydroxyethyl acrylate (monofunctional monomer)

BZA: benzyl acrylate (monofunctional monomer)

OPPEA: O-phenylphenoxyethyl acrylate (monofunctional monomer)

NPGDA: neopentyl glycol diacrylate (bifunctional monomer)

BPADA: Bisphenol A diacrylate (bifunctional monomer)

MDHEA: Dehydrogenated epoxy diacrylate synthesized in Synthesis Example 5 (bifunctional monomer)

TMPTA: trimethylpropane triacrylate (trifunctional monomer)

PETA: pentaerythritol triacrylate (trifunctional monomer)

PETTA: pentaerythritol tetraacrylate (tetrafunctional monomer)

DPPA: dipentaerythritol pentaacrylate (bifunctional monomer)

DPHA: dipentaerythritol nuclear acrylate (hexafunctional monomer)

TPO: photoinitiator (trade name: Irgacure ^® TPO, manufactured by BASF, Germany)

I-184: Photoinitiator (trade name: Irgacure ^® 184, manufactured by BASF, Germany)

T-99-2: ultraviolet absorber (trade name: Tinuvin ^® 99-2, manufactured by BASF, Germany)

T-292: ultraviolet stabilizer (trade name: Tinuvin ^® 292, manufactured by BASF, Germany)

I-1010: Antioxidant (trade name: Irganox ^® 1010, manufactured by BASF, Germany)

Table 1 and Table 2 show experimental results of the examples of the adhesive composition for quantum dot sheets, and Table 3 shows experimental results of the compositions of the comparative examples.

As shown in Tables 1 and 2, the polyfunctional (meth) acrylate polymer of Formula 1, the urethane acrylate oligomer of Formula 2, the acrylate monomer and the photoinitiator according to the present invention, The adhesive properties of the adhesive for a quantum dot sheet were superior to those of Comparative Examples 1 to 10 in which the modified epoxy oligomer containing the modified epoxy oligomer was not used, and the optical characteristics such as light transmittance, luminance, chromaticity coordinate and color deviation were excellent, And a non-barrier sheet having a moisture permeability of 10 < ^-1 > g / m < ² > day or more can be used to form a quantum dot sheet. 60 ° C, relative humidity of 90% and 500 hours of life Accelerating the application of a quantum dot sheet It was confirmed that composition.

On the other hand, in the case of the composition excluding the multifunctional (meth) acrylate polymer of the formula (1) in the comparative examples 1 and 2, the light transmittance and the luminance were lowered, the color coordinate was defective, the color deviation was increased, the adhesion was poor, It was confirmed that defects were generated in the evaluation.

In the compositions of Comparative Examples 3 and 4 except for the urethane acrylate oligomer of Formula 2 and the epoxy acrylate oligomer of Formula 3, there was no abnormality in the light transmittance and the brightness, but the color coordinates were defective and the color deviation was increased, And it was confirmed that the reliability evaluation resulted in failure.

In Comparative Examples 5 and 6, when the monomer monomer was excluded from the composition, the viscosity became very high, the workability of the quantum dot sheet became very poor, the dispersibility of the quantum dot and the light scattering agent became very poor, and the light transmittance, appear. As a result, it was confirmed that the reliability evaluation of the quantum dot sheet with poor adhesion finally resulted in defects.

In Comparative Examples 7 and 8, when the polyfunctional (meth) acrylate polymer of Formula 1, the urethane acrylate oligomer of Formula 2 and the epoxy acrylate oligomer of Formula 3 were both excluded, the viscosity decreased to 100 cps or less, And the dispersibility and light transmittance of the quantum dot and the light scattering agent were excellent, but the color coordinates and color deviation were poor. In addition, adhesion was scarcely generated, and it was confirmed that a defect was finally generated in the reliability evaluation of the quantum dot sheet.

Comparative Example 9 is a case where the photocuring agent was excluded from the composition components of Example 12, and the photocuring was not carried out, and the quantum dot sheet could not be formed.

In Comparative Example 10, when the additive was excluded from the composition of Example 12, the adhesive for a quantum dot sheet was excellent in optical properties such as light transmittance, luminance, color coordinate and color deviation, excellent dispersibility of quantum dots and light scattering agent, A non-barrier sheet having an adhesive strength and a moisture permeability of 10 ^-1 g / m ² · day or more was used. However, the reliability evaluation criteria of temperature 60 ° C. and relative humidity 90 RH % And 500 hours, the error of color coordinates and color deviation occurred. Therefore, it was confirmed that these additives are important factors in the reliability of the quantum dot sheet.

Then, evaluation of brightness, uniformity, color coordinates and color deviation of the 55-inch quantum dot sheet prepared using the adhesive composition for quantum dot sheet of Example 12 was carried out. The fabricated quantum dot sheet was a non-barrier film, and optical characteristics and reliability evaluation were performed on the quantum dot sheet punched with a blade-cut. Particularly, the punching by blade-cut is very advantageous in terms of mass production and economy since it is much faster than laser-cut cutting. On the contrary, in the case of a quantum dot sheet of a competitor that has been evaluated for comparison in the present experiment, it is a quantum dot sheet manufactured using a barrier sheet having a moisture permeability of 10 ^-2 g / m ² · day or less.

Table 4 below shows evaluation results of brightness, uniformity, color coordinates, and color deviation for a 55-inch quantum dot sheet of a competitor and a 55-inch quantum dot sheet prepared using the adhesive composition of Example 13. [ In the case of luminance, the quantum dot sheet of Example 13 was 13.4% larger than that of the competitive quantum dot sheet in terms of color coordinates, color deviation, and uniformity, and the color recall ratio NTSC 1931) also increased by 2.9% compared to existing competitors. On the other hand, the thickness of the quantum dot adhesive in which the quantum dots of the quantum dot sheet and the light scattering agent are dispersed decreased by 2 μm.

The following Table 5 shows the results of the life acceleration test (reliability) of the 55-inch quantum dot sheet and the competitive quantum dot sheet prepared using the adhesive composition for a quantum dot sheet of Example 12 at a temperature of 60 DEG C and a relative humidity of 90% for 500 hours The results are shown. In conclusion, both products show excellent reliability. That is, in the competitive quantum dot sheet, the average luminance after 500 hours shows 99.0% of the initial value, and the 55-inch quantum dot sheet manufactured using the adhesive composition for a quantum dot sheet of Example 12 also has an average brightness after 500 hours Of the total. Color coordinates and color deviation were also confirmed after 500 hours of reliability experiment that both products did not show much change compared to initial value. The competitive quantum dot sheet is a quantum dot sheet made of a barrier sheet having a moisture permeability of 10 ^-2 g / m ² · day or less, and is compared with the quantum dot sheet of the present invention using a non-barrier sheet. , It was confirmed that the composition of Example 12 had excellent moisture-proofing performance.

Time (hrs) The quantum dot sheet prepared using the composition of Example 12 Competitor quantum dot sheet Average brightness (nit,%) Center color coordinate (x / y) The color deviation (DELTA x / DELTA y) Average brightness (nit,%) Center color coordinate (x / y) The color deviation (DELTA x / DELTA y) 0 100 0.2437 / 0.2165 - 100.0 0.2427 / 0.2091 - 144 101.1 0.2460 / 0.2167 0.0023 / 0.0002 99.7 0.2429 / 0.2086 0.0002 / 0.0005 288 98.0 0.2460 / 0.2181 0.0023 / 0.0016 99.6 0.2424 / 0.2075 0.0003 / 0.0016 360 97.2 0.2415 / 0.2147 0.0022 / 0.0018 98.2 0.2422 / 0.2071 0.0005 / 0.0020 440 97.4 0.2469 / 0.2149 0.0032 / 0.0016 96.0 0.2425 / 0.2076 0.0002 / 0.0015 500 98.9 0.2509 / 0.2201 0.0072 / 0.0036 99.0 0.2429 / 0.2079 0.0002 / 0.0012

Table 6 below shows a schematic structure of a conventional quantum dot sheet including a barrier layer and a non-barrier quantum dot sheet from which a barrier layer of the present invention is deleted. In the above concrete evaluation results, It is summarized.

The adhesive composition for a quantum dot sheet according to the present invention maximizes the application of a barrier property to prevent moisture permeability to a quantum dot dispersing adhesive (binder resin), thereby eliminating the necessity of using an expensive barrier film as a separate component (BLU) and a display device by providing a quantum dot sheet having a uniform thickness.

Claims (15)

10 to 30% by weight of a polyfunctional (meth) acrylate polymer represented by the following formula (1), 10 to 60% by weight of a urethane acrylate oligomer of the following formula (2), 10 to 60% by weight of an acrylate monomer and 0.1 to 10% The adhesive composition for a quantum dot sheet according to the present invention.
(Formula 1)

(In the general formula 1 R ₁ is hydrogen (H-) or methyl (CH ₃ - a), R ₂ is a hydrophobic straight chain hydrocarbon groups, branched hydrocarbon groups, cycloaliphatic hydrocarbon group, an aromatic group, an alkyl or aromatic group, R ₃ is a hydrophilic hydroxyl groups (-OH), a hydroxyl hydrocarbon groups, a carboxyl group (-COOH), a carboxyl hydrocarbon group, an amine group (-NH _2), a hydrocarbon group, a polyethylene glycol, or polypropylene glycol containing an amino group, R ₄ An aromatic group or an alkylaromatic group having a Tg value of at least 80 degrees, and n, m and l are each independently an integer of 0 or more, and 100? N + m +
(2)

(In the formula R ₁ 2 is hydrogen (H-) or methyl (CH ₃ - a), and, R ₂ is a straight-chain hydrocarbon groups, branched hydrocarbon groups, cycloaliphatic hydrocarbon group, an aromatic group, an alkyl or aromatic group, R ₃ is Propylene oxide adduct type bisphenol group, dehydrogenated bisphenol group, ethylene oxide adduct type dehydrogenated bisphenol group, or propylene oxide adduct type dehydrogenated bisphenol group, and m is an integer of 1 or more Lt; = m < = 100). The adhesive composition for a quantum dot sheet according to claim 1, further comprising 10 to 60% by weight of a modified epoxy oligomer of the following formula (3).
(Formula 3)

(Wherein R ₁ is hydrogen (H-) or methyl group (CH ₃ -) and n is an integer of 0 or more, and 0? N? The composition of claim 1 wherein said acrylate monomer is selected from the group consisting of tetrahydrofuryl acrylate (THFA), tetrahydrofuryl methacrylate (THFMA), cyclic trimethylolpropane foam acrylate (CTFA), 3,3,5-trimethyl (MMA), methyl acrylate (MA), methacrylic acid (MAA), ethyl methacrylate (MMA), isobornyl methacrylate (IBOA), isobornyl methacrylate (EMA), ethyl acrylate (EA), n-butyl methacrylate (BMA), isobutyl methacrylate (IBMA), t-butyl methacrylate (TBMA) EHA), 2-ethylhexyl methacrylate (2-EHMA), lauryl acrylate (LA), lauryl (EO) ₂ acrylate (LA (EO) ₂ A), isooctyl acrylate Octyl methacrylate (IOMA), isodecyl acrylate (IDA), isodecyl methacrylate (IDMA) , Testadecyl acrylate (TDA), cetyl acrylate (CA), stearyl acrylate (SA), icosyl acrylate (ICSA), behenyl acrylate (BHA), 2-hydroxyethyl acrylate (2-hydroxyethyl methacrylate), 2-hydroxypropyl methacrylate (2-HPA), 2-hydroxypropyl methacrylate (2-HBA), 2-hydroxybutyl methacrylate (2-HBMA), 2-hydroxy-3-phenoxypropyl acrylate (HPPA), caprolactone acrylate (EO) methacrylate (MA (EO) MA), phthalic acid (EO) acrylate (PA (EO) ) A), phthalic acid (EO) methacrylate (PA (EO) MA), succinic acid (EO) acrylate (SA (EO) A), succinic acid (EO) - carboxyethyl acrylate (2-CEA), ethoxyethoxyethyl acrylate (EOEOEA), glycidyl methacrylate (GMA), ethoxy triethylene glycol methacrylate (ETEGMA), polyethylene glycol monoacrylate (PEGMA), polyethylene glycol monomethacrylate (PEGMMA), polyalkylene glycol mono Acrylate (PAGMMA), polypropylene glycol monomethacrylate (PPGMMA), N, N-dimethylacrylamide (DMAA), acrylonylmorpholine (ACMO), N- vinyl-2-pyrrolidone benzyl acrylate (BZA), benzyl methacrylate (BZMA), phenoxyethyl acrylate (PHEA), phenoxy (EO) ₂ acrylate _{(PH (EO) 2 A)} , phenoxy (EO) ₄ acrylate ( (EO) ₄ A), nonylphenoxy (EO) ₄ acrylate (NPH (EO) ₄ A), nonylphenoxy (EO) ₈ acrylate (NPH (EO) ₈ A), nonylphenoxy (PO) _2- acrylate (NPH (PO) ₂ A), phenoxybenzyl acrylate (PBA), 4-cumylphenoxy ethyl acrylate (CPEA), O-phenyl phenoxy ethyl acrylate (OPPEA) (EO) ₂ acrylate (OPP (EO) ₂ A), 1,4-butanediol diacrylate (BDDA), 1,4-butanediol dimethacrylate (BDDMA), 1,6-hexanediol diacrylate (HDDA), 1,6-hexanediol dimethacrylate (HDDMA), 1,10-decanediol diacrylate (DDDA), diethylene glycol diacrylate (DEGDA), triethylene glycol diacrylate (TEGDA) , Polyethylene glycol diacrylate (PEGDA), polyethylene glycol dimethacrylate (PEGDMA), dipropylene glycol diacrylate (DPGDA), tripropylene glycol diacrylate (TPGDA), polypropylene glycol diacrylate (PPGDA) Polypropylene glycol dimethacrylate (PPGDMA), neopentyl glycol diacrylate (NPGDA), cyclohexanedimethanol diacrylate (CHDMDA), dicyclodecane dimethanol diacrylate (DCDDMDA), bisphenol A diacrylate BPADA) ethylene oxide addition type derivatives, bis (BPADDA) ethylene oxide addition type derivatives, bisphenol fluorene diacrylate (BPFDA) ethylene oxide addition type derivatives, trimethyl propane triacrylate (TMPTA), trimethyl propane triacrylate (TMPTA) ethylene oxide addition type derivatives, Trimethylolpropane trimethacrylate (TMPTMA), trimethylpropane trimethyl acrylate (TMPTMA) ethylene oxide addition type derivatives, pentaerythritol triacrylate (PETA), pentaerythritol trimethacrylate (PETMA), glycerin (PO) ₃ Triethoxysilane triacrylate (G (PO) ₃ TA), tri (2-hydroxyethyl) isoionate triacrylate (THEIC), tris- Propane tetraacrylate (DTMPTA), pentaerythritol tetraacrylate (PETTA), pentaerythritol tetraacrylate (DPHA), dipentaerythritol hexaacrylate (DPHA), and dipentaerythritol hexaacrylate (DPHA) ethylene oxide addition-type derivatives, from the group consisting of ethylene oxide addition product derivatives, dipentaerythritol pentaacrylate Wherein at least one kind of monomer selected is low-moisture-permeability. The adhesive composition for a quantum dot sheet according to claim 1, wherein said photoinitiator is a low-moisture-permeability, which is a hydroxyketone photoinitiator, an amino ketone photoinitiator, a phenylglyoxylate photoinitiator, a benzyldimethylketalate photoinitiator, . 5. The composition of claim 4 wherein said photoinitiator is selected from the group consisting of 1-hydroxycyclohexyl phenyl ketone, benzophenone, 2-hydroxy-2-methyl-1-phenyl- (2-oxo-2-phenyl-acetoxy-ethoxy) -ethyl ester, Alpha-dimethoxy-alpha-phenylacetophenone, 2-benzoyl-2- (dimethylamino) -1- [4 (4-morpholinyl) phenyl] -1-butanone, 2-methyl-1- [4- , 4,6-trimethylbenzonyl) -phosphine oxide, phosphine oxide phenylbis (2,4,6-trimethylbenzonyl), bis (eta 5-2,4-cyclopentadien- (4-methylphenyl) [4- (2-methylpropyl) phenyl] -hexafluorophosphate (prepared by reacting 2,6-difluoro-3- -), diphenyl ketone benz 4-hydroxycyclophenyl ketone, dimethoxy-2-phenylacetophenone, anthraquinone, fluorene, triphenylamine, carbazole, 3-methylacetophenone, 4-dimethoxyacetophenone, and 4,4-diaminobenzophenone. The adhesive composition for a quantum dot sheet according to claim 1, wherein the at least one photoinitiator is a photoinitiator. The adhesive composition for a quantum dot sheet according to claim 1, wherein the adhesive composition for a quantum dot sheet comprises an antioxidant, a UV absorber, a light stabilizer, a thermal polymerization inhibitor, a leveling agent, a surfactant, an antifouling agent, To 5% by weight of the total weight of the composition. The adhesive composition for a quantum dot sheet according to claim 1, wherein the adhesive composition for a quantum dot sheet has a viscosity of 50 to 3,000 cps and a refractive index of 1.40 to 1.55. The adhesive composition for a quantum dot sheet according to claim 1, wherein the adhesive composition for a quantum dot sheet has a low moisture permeability including a quantum dot nanoparticle and a light scattering agent nano or micro particle in a homogeneously dispersed state. Lt; RTI ID = 0.0 >% < / RTI > 9. The method of claim 8, wherein the quantum dot nanoparticles are selected from the group consisting of CdSe, CdSe / ZnS, CdTe, CdTe / CdS, ZnSe / ZnS, ZnTe / ZnSe, PbSe, PbS, InP, InGaP, InGaP / ZnS, , And HeTe, which is at least one kind of quantum dot nanoparticles. The method of claim 8, wherein the light scattering agent nano- or microparticles are selected from the group consisting of Al ₂ O ₃ , ZnO, SiO ₂ , ZrO ₂ , SnO ₂ , CeO ₂ , MgO, CaO, TiO ₂ , Y ₂ O ₃ , Sb ₂ O ₃ , BaTiO _3, and Fe ₃ O _4, as a light-scattering agent. 8. A quantum dot sheet adhesive composition in which quantum dot nanoparticles and light scattering agent nano- or microparticles dispersed according to claim 8 are interposed between two non-barrier optical films or sheets in an optically hardened adhesive layer A quantum dot sheet. The quantum dot sheet according to claim 11, wherein the adhesive layer has a thickness of 20 to 200 占 퐉. The quantum dot sheet according to claim 11, wherein the quantum dot sheet has a moisture permeability of 10 ^-1 g / m ² · day or more. A backlight unit (BLU) comprising a quantum dot sheet to which a non-barrier optical film or optical sheet according to claim 11 is applied. A liquid crystal display device comprising the backlight unit according to claim 14 and having color reproducibility equal to that of AMOLED.