CN111650774A

CN111650774A - Display device

Info

Publication number: CN111650774A
Application number: CN202010143088.8A
Authority: CN
Inventors: 柳娥凛; 金智恩; 金智惠; 李珍雅; 郑周昊; 韩圭奭
Original assignee: Samsung SDI Co Ltd
Current assignee: Samsung SDI Co Ltd
Priority date: 2019-03-04
Filing date: 2020-03-04
Publication date: 2020-09-11
Anticipated expiration: 2040-03-04
Also published as: TWI753372B; KR20200106356A; KR102409453B1; TW202033672A; CN111650774B

Abstract

The invention discloses a display device, the display device includes: a light source configured to emit light at a wavelength of 400nm to 500nm and a light intensity at a wavelength of 420nm is greater than or equal to 3% of a maximum light intensity of the light source; a quantum dot containing layer disposed on the light source; a pressure-sensitive adhesive layer disposed on the quantum dot containing layer; and a blue filter layer disposed on the pressure-sensitive adhesive layer, wherein an intensity of light at a wavelength of 420nm after the light from the light source passes through the quantum dot containing layer, the pressure-sensitive adhesive layer, and the blue filter layer is less than or equal to 1% of a maximum intensity of the light.

Description

Display device

[ CROSS-REFERENCE TO RELATED APPLICATIONS ]

The present application claims the priority and rights of korean patent application No. 10-2019-0024788, which was filed by the korean intellectual property office on 3/4/2019, the entire contents of which are incorporated herein by reference.

Technical Field

The present disclosure relates to a display device including quantum dots.

Background

A content quantum dot display material that is recently commercially available or under development utilizes light emission of green and red quantum dots by a blue light source or a white light source. Quantum dot-containing display devices improve color reproducibility and brightness by using quantum dot materials, and panels using quantum dot light emission by using various types of light sources are continuously developed. Furthermore, the viewing angle depending on the application position of the quantum dot material in the panel construction can be improved. The next generation of quantum dot display devices is moving toward increasing the intensity of light sources or developing light sources having an enlarged blue region to improve the luminous efficiency of quantum dots, which is technically very important.

Regarding the quantum dot display device, the spectrum of light sources reaching the quantum dot material has a very close influence on the efficiency of the quantum dots, and at present, its characteristics are different according to the type of light source, and thus, various efforts are being made to introduce new methods to improve the efficiency of the quantum dots according to each light source.

Disclosure of Invention

An embodiment provides a display device having high color reproducibility and improved luminance by increasing quantum dot efficiency.

An embodiment provides a display device, including: a light source configured to emit light at a wavelength of 400nm to 500nm and a light intensity at a wavelength of 420nm is greater than or equal to 3% of a maximum light intensity of the light source; a quantum dot containing layer disposed on the light source; a pressure-sensitive adhesive layer disposed on the quantum dot containing layer; and a blue filter layer disposed on the pressure-sensitive adhesive layer, wherein an intensity of light at a wavelength of 420nm after the light from the light source passes through the quantum dot containing layer, the pressure-sensitive adhesive layer, and the blue filter layer is less than or equal to 1% of a maximum intensity of the light.

One of the pressure-sensitive adhesive layer and the blue filter layer can have an absorbance of less than 50% at a wavelength of less than or equal to 420 nm.

The pressure-sensitive adhesive layer can have an absorbance of greater than or equal to 50% at a wavelength of less than or equal to 420 nm.

The blue filter layer may have an absorbance of greater than or equal to 50% at a wavelength of less than or equal to 420 nm.

The pressure-sensitive adhesive layer or the blue filter layer may include one or more of azo dyes, azomethine dyes, and porphyrin dyes.

The azomethine-based dye may be represented by chemical formula 1.

[ chemical formula 1]

In the chemical formula 1, the first and second,

m is Zn, Co, Cu or V,

X¹to X⁴Each independently an oxygen atom or a sulfur atom,

R¹to R⁴Each independently is a halogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C1 to C20 alkoxy group, a mercapto group, or a substituted or unsubstituted C1 to C20 alkyl thiol group, and

n1 to n4 are each independently an integer from 0 to 4.

The azomethine-based dye represented by chemical formula 1 may be represented by one of chemical formulae 1-1 to 1-7.

[ chemical formula 1-1]

[ chemical formulas 1-2]

[ chemical formulas 1-3]

[ chemical formulas 1 to 4]

[ chemical formulas 1 to 5]

[ chemical formulas 1 to 6]

[ chemical formulas 1 to 7]

The porphyrin-based dye may be represented by chemical formula 2.

[ chemical formula 2]

In the chemical formula 2, the first and second organic solvents,

m is Zn, Co, Cu or V,

R⁵to R¹²Each independently is a halogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstitutedA C1 to C20 alkoxy group, a substituted or unsubstituted C6 to C20 aryl group, a sulfonic acid group, a substituted or unsubstituted sulfonamide group, or a substituted or unsubstituted C1 to C20 alkyl ester group, and

n5 to n12 are each independently an integer of 0 or 1, with the proviso that 1. ltoreq. n5+ n 6. ltoreq.2, 1. ltoreq. n7+ n 8. ltoreq.2, 1. ltoreq. n9+ n 10. ltoreq.2, and 1. ltoreq. n11+ n 12. ltoreq.2.

The porphyrin-based dye represented by chemical formula 2 may be represented by one of chemical formulas 2-1 to 2-20.

[ chemical formula 2-1]

[ chemical formula 2-2]

[ chemical formulas 2-3]

[ chemical formulas 2-4]

[ chemical formulas 2 to 5]

[ chemical formulas 2 to 6]

[ chemical formulae 2 to 7]

[ chemical formulas 2 to 8]

[ chemical formulas 2 to 9]

[ chemical formulas 2-10]

[ chemical formulas 2 to 11]

[ chemical formulas 2-12]

[ chemical formulas 2-13]

In the chemical formulae 2 to 13,

r is a hydrogen atom or a substituted or unsubstituted C1 to C20 alkyl group, and

m1 and m2 are each independently an integer of 0 to 20, with the proviso that 4. ltoreq. m1+ m 2. ltoreq.20,

[ chemical formulae 2 to 14]

[ chemical formulas 2 to 15]

[ chemical formulas 2 to 16]

[ chemical formulas 2 to 17]

[ chemical formulas 2 to 18]

[ chemical formulae 2 to 19]

[ chemical formulas 2-20]

The quantum dots may include green quantum dots, red quantum dots, or a combination thereof.

The display device may further include a liquid crystal layer between the pressure-sensitive adhesive layer and the blue filter layer.

The display device may further include an overcoat layer between the liquid crystal layer and the blue filter layer.

The quantum dot containing layer may also include a diffusing agent.

The dispersing agent may include barium sulfate, calcium carbonate, titanium dioxide, zirconium oxide, or combinations thereof.

Other embodiments of the invention are included in the following detailed description.

The display device may be capable of achieving high color reproduction and excellent luminance by improving light conversion efficiency of quantum dots while preventing deterioration of blue purity.

Drawings

Fig. 1 is a schematic view illustrating a display device according to an embodiment.

Fig. 2 is a graph showing an absorption spectrum of a quantum dot and an absorption spectrum of a conventional (blue) light source used in a display device.

Fig. 3 is a graph showing the spectrum of a light source.

Fig. 4 is a graph showing a spectrum of the pressure-sensitive adhesive layer.

Fig. 5 is a graph showing the spectrum of the blue filter layer.

Fig. 6 is a graph showing the spectrum of light passing through the blue filter layer (example 1, example 2, and comparative example 2).

[ description of symbols ]

1: light guide plate

2: layer containing quantum dots

3: liquid crystal layer

4: outer coating

5: glass

6: blue filter layer

9: quantum dot/green quantum dot

10: quantum dot/red quantum dot

11: dispersing agent

12: pressure-sensitive adhesive layer

Detailed Description

Hereinafter, examples of the present invention are explained in detail. However, these embodiments are exemplary, the present invention is not limited thereto and the present invention is defined by the scope of the claims.

In the present specification, when a specific definition is not otherwise provided, "alkyl" means C1 to C20 alkyl, "alkenyl" means C2 to C20 alkenyl, "cycloalkenyl" means C3 to C20 cycloalkenyl, "heterocycloalkenyl" means C3 to C20 heterocycloalkenyl, "aryl" means C6 to C20 aryl, "arylalkyl" means C6 to C20 arylalkyl, "alkylene" means C1 to C20 alkylene, "arylene" means C6 to C20 arylene, "alkylarylene" means C6 to C20 alkylarylene, "heteroarylene" means C3 to C20 heteroarylene, and "alkyleneoxy" means C1 to C20 alkyleneoxy.

In the present specification, when a specific definition is not otherwise provided, "substituted" means that at least one hydrogen atom is replaced with a substituent selected from the group consisting of: halogen atoms (F, Cl, Br, or I), hydroxyl groups, C1 to C20 alkoxy groups, nitro groups, cyano groups, amine groups, imino groups, azido groups, amidino groups, hydrazino groups, hydrazono groups, carbonyl groups, carbamoyl groups, thiol groups (thiol groups), ester groups, ether groups, carboxyl groups or salts thereof, sulfonic acid groups or salts thereof, phosphoric acid or salts thereof, C1 to C20 alkyl groups, C2 to C20 alkenyl groups, C2 to C20 alkynyl groups, C6 to C20 aryl groups, C3 to C20 cycloalkyl groups, C3 to C20 cycloalkenyl groups, C3 to C20 cycloalkynyl groups, C2 to C20 heterocycloalkyl groups, C2 to C20 heterocycloalkenyl groups, C2 to C20 heterocycloalkynyl groups, C3 to C20 heteroaryl groups, or combinations thereof.

In the present specification, when a specific definition is not otherwise provided, "hetero" means that at least one hetero atom selected from N, O, S and P is contained in the chemical formula.

In the present specification, "(meth) acrylate" means both "acrylate" and "methacrylate", and "(meth) acrylic acid" means "acrylic acid" and "methacrylic acid", when a specific definition is not otherwise provided.

In the present specification, the term "combination" when a definition is not otherwise provided means mixing or copolymerization.

In the present specification, when a definition is not otherwise provided, when a chemical bond is not drawn at a position that should be given in a chemical formula, the hydrogen bond is bonded at the position.

In addition, in the present specification, "+" refers to a point connected to the same or different atom or chemical formula, when no definition is otherwise provided.

The display device according to the embodiment includes: a light source configured to emit light at a wavelength of 400nm to 500nm and a light intensity at a wavelength of 420nm is greater than or equal to 3% of a maximum light intensity of the light source; a quantum dot containing layer disposed on the light source; a pressure-sensitive adhesive layer disposed on the quantum dot containing layer; and a blue filter layer disposed on the pressure-sensitive adhesive layer, wherein an intensity of light at a wavelength of 420nm after the light from the light source passes through the quantum dot containing layer, the pressure-sensitive adhesive layer, and the blue filter layer is less than or equal to 1% of a maximum intensity of the light.

The green quantum dots and the red quantum dots absorb light of a blue light source (a Light Emitting Diode (LED), an Organic Light Emitting Diode (OLED), or the like), respectively, to emit light.

The conventional quantum dot-containing display device uses a blue light emitting diode having a sharp spectrum (sharp spectrum) with a maximum intensity (maximum light intensity) at about 450nm as a light source on which a sheet or chip including quantum dots or the like is present (see fig. 2), and thus, a part of blue light is converted into green/red and thus becomes white including both red/green/blue. Since quantum dots have very high conversion efficiencies (quantum yields, QY) of up to about 90%, but have very little absorption in the blue spectrum around 450nm, the total light dose converted to green/red in essence can be relatively small. Since the absorption spectrum of the quantum dot actually shows a greater absorption in the violet or Ultraviolet (UV) region than in the blue region (see fig. 2), the quantum dot can emit brighter light in a light source of a shorter wavelength region. However, when there is a spectrum of a shorter wavelength region, the color purity of blue light is deteriorated, and thus the color reproducibility is deteriorated, which weakens the reason why the quantum dot containing display is used (high color reproduction), and therefore, the light source of the shorter wavelength region is less useful for the quantum dot containing display. Incidentally, when a light source of a shorter wavelength region is not used, the luminance of the quantum dot display is deteriorated.

An embodiment provides a display device including quantum dots activated by a light source (backlight unit) that emits light having an intensity of greater than or equal to 3% of a maximum intensity at a wavelength of less than or equal to 420nm, for example, at a wavelength of 420nm, but has a reduced intensity of less than or equal to 1% of the maximum intensity due to absorption of coloring materials included in an adhesive layer and a blue filter layer after passing through a quantum dot-containing layer, and thus, an absorption region of the quantum dots may be improved and a significant conversion efficiency of the quantum dots may be increased, thereby improving brightness over the entire panel, while not sacrificing color purity of blue light. In addition, the display device having such a structure may be more efficient than increasing the transmittance of each color filter (red filter layer, green filter layer, blue filter layer).

In other words, the display device according to the embodiment may be designed to use a light source different from that used for a conventional display device to emit light at a wavelength of 400nm to 500nm and a light intensity at a wavelength of 420nm is greater than or equal to 3% of the maximum light intensity, while the light intensity is reduced to less than or equal to 1% of the maximum light intensity when passing through the quantum dot containing layer, the pressure-sensitive adhesive layer, and the blue filter layer, and thus, high color and high brightness may be simultaneously realized.

Specifically, any of the pressure-sensitive adhesive layer and the blue filter layer can have an absorbance of less than 50% at a wavelength of less than or equal to 420nm, such as at a wavelength of 420 nm. In other words, either one of the pressure-sensitive adhesive layer and the blue filter layer may have an absorbance of greater than or equal to 50% at a wavelength of less than or equal to 420nm, for example, at a wavelength of 420nm, while the other may have an absorbance of less than 50% at a wavelength of less than or equal to 420nm, for example, at a wavelength of 420 nm. For example, when both the pressure-sensitive adhesive layer and the blue filter layer may have an absorptance of greater than or equal to 50% at a wavelength of less than or equal to 420nm, for example, at a wavelength of 420nm, the color purity of the finally realized blue light is deteriorated, and therefore, the color reproducibility of the entire display may be deteriorated.

For example, the pressure-sensitive adhesive layer or the blue filter layer may contain an azo-based dye, an azomethine-based dye, or a porphyrin-based dye, but is not necessarily limited thereto, and any material having an absorbance of 50% or more at a wavelength of 420nm or less, for example, at a wavelength of 420nm, may be contained in the pressure-sensitive adhesive layer or the blue filter layer.

For example, when the pressure-sensitive adhesive layer contains an azo-based dye, an azomethine-based dye, or a porphyrin-based dye, the blue filter layer may not contain the azo-based dye, the azomethine-based dye, and the porphyrin-based dye.

For example, when the blue filter layer contains an azo-based dye, an azomethine-based dye, or a porphyrin-based dye, the pressure-sensitive adhesive layer may not contain an azo-based dye, an azomethine-based dye, or a porphyrin-based dye.

For example, the azomethine-based dye may be represented by chemical formula 1.

[ chemical formula 1]

In the chemical formula 1, the first and second,

m is Zn, Co, Cu or V,

X¹to X⁴Each independently an oxygen atom or a sulfur atom,

n1 to n4 are each independently an integer from 0 to 4.

For example, the azomethine-based dye represented by chemical formula 1 may be represented by one of chemical formulas 1-1 to 1-7, but is not necessarily limited thereto.

[ chemical formula 1-1]

[ chemical formulas 1-2]

[ chemical formulas 1-3]

[ chemical formulas 1 to 4]

[ chemical formulas 1 to 5]

[ chemical formulas 1 to 6]

[ chemical formulas 1 to 7]

For example, the porphyrin-based dye may be represented by chemical formula 2.

[ chemical formula 2]

In the chemical formula 2, the first and second organic solvents,

m is Zn, Co, Cu or V,

R⁵to R¹²Each independently is a halogen atom, a substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C6 to C20 aryl group, a sulfonic acid group, a substituted or unsubstituted sulfonamide group, or a substituted or unsubstituted C1 to C20 alkyl ester group, and

For example, the porphyrin-based dye represented by chemical formula 2 may be represented by one of chemical formula 2-1 to chemical formula 2-20, but is not necessarily limited thereto.

[ chemical formula 2-1]

[ chemical formula 2-2]

[ chemical formulas 2-3]

[ chemical formulas 2-4]

[ chemical formulas 2 to 5]

[ chemical formulas 2 to 6]

[ chemical formulae 2 to 7]

[ chemical formulas 2 to 8]

[ chemical formulas 2 to 9]

[ chemical formulas 2-10]

[ chemical formulas 2 to 11]

[ chemical formulas 2-12]

[ chemical formulas 2-13]

In the chemical formulae 2 to 13,

[ chemical formulae 2 to 14]

[ chemical formulas 2 to 15]

[ chemical formulas 2 to 16]

[ chemical formulas 2 to 17]

[ chemical formulas 2 to 18]

[ chemical formulae 2 to 19]

[ chemical formulas 2-20]

For example, the display device may further include a liquid crystal layer between the pressure-sensitive adhesive layer and the blue filter layer. In addition, the display device may further include an overcoat layer between the liquid crystal layer and the blue filter layer.

Referring to fig. 1, the display device includes a blue filter layer 6 and a quantum dot containing layer 2 facing each other with respect to a liquid crystal layer 3, and a pressure-sensitive adhesive layer 12 between the liquid crystal layer 3 and the quantum dot containing layer 2, wherein the blue filter layer 6 includes a blue filter beside a columnar spacer (not shown). An overcoat layer 4 may also be included between the liquid crystal layer 3 and the blue filter layer 6. The quantum dot-containing layer 2 may further include a diffusing agent 11 in addition to the

quantum dots

9 and 10. A silicon oxide deposition layer (not shown) may be present on the surface of the quantum dot containing layer 2, and the silicon oxide deposition layer may absorb blue light from the light source through the light guide plate 1. On the blue filter layer 6, glass 5 is provided.

Since the quantum dot-containing layer is composed of a layer different from the blue filter layer and the display device further includes the pressure-sensitive adhesive layer between the quantum dot-containing layer and the blue filter layer, deterioration of quantum efficiency of the quantum dots can be prevented. In addition, the light guide plate may not be a polymethyl methacrylate (PMMA) light guide plate, but a glass light guide plate. A glass light guide plate is used instead of the polymethylmethacrylate light guide plate, and thus may contribute to thinning of the panel and improvement of brightness.

The quantum dot-containing layer may contain, in addition to the quantum dots, a binder resin, a reactive unsaturated compound, a diffusing agent, and other additives, which will be described later.

The quantum dot may have a maximum absorption wavelength at 460nm to 490nm in a wavelength region of 440nm to 550 nm.

The quantum dots can have a full width at half maximum (FWHM) of 20nm to 100nm, e.g., 20nm to 50 nm. When the quantum dot has a full width at half maximum (FWHM) of the range, color reproducibility increases when used as a color material in a color filter due to high color purity.

The quantum dots may each independently be an organic material or an inorganic material or a hybrid (mixture) of an organic material and an inorganic material.

The quantum dots may each independently be composed of a core and a shell surrounding the core, and the core and the shell may each independently have a structure of a core, a core/shell, a core/first shell/second shell, an alloy/shell, etc., composed of groups II-IV, III-V, etc., but are not limited thereto.

For example, the core may include at least one material selected from CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, HgS, HgSe, HgTe, GaN, GaP, GaAs, InP, InAs, and alloys thereof, but is not necessarily limited thereto. The shell surrounding the core may contain at least one material selected from CdSe, ZnSe, ZnS, ZnTe, CdTe, PbS, TiO, SrSe, HgSe, and alloys thereof, but is not necessarily limited thereto.

In one embodiment, as the interest in the environment has increased greatly worldwide recently and the regulation of toxic materials has also been strengthened, a non-cadmium based luminescent material (InP/ZnS) having a slightly low quantum efficiency (quantum yield) but being environmentally friendly is used instead of the luminescent material having a cadmium based core, but is not necessarily limited thereto.

The structure of the quantum dot is not particularly limited, but in the case of a core/shell structured quantum dot, the structure of the quantum dot may have an overall size of 1nm to 15nm, for example, 5nm to 15nm, including a shell (average particle diameter).

For example, the quantum dots may include red quantum dots, green quantum dots, or a combination thereof. For example, quantum dots may include both green and red quantum dots. Here, the green quantum dots may be included in a greater amount than the red quantum dots. The red quantum dots may have an average particle size of 10nm to 15 nm. The green quantum dots may have an average particle size of 5nm to 8 nm.

On the other hand, a dispersant may be further included to obtain dispersion stability of the quantum dot. The dispersant contributes to uniform dispersibility of the light conversion material such as quantum dots in the curable composition, and may include a nonionic dispersant, an anionic dispersant, or a cationic dispersant. Specifically, the dispersant may be a polyalkylene glycol or an ester thereof, a polyoxyalkylene, a polyol ester alkylene oxide addition product, an alcohol alkylene oxide addition product, a sulfonate, a carboxylic ester, a carboxylic salt, an alkylamide alkylene oxide addition product, an alkylamine, or the like, and these dispersants may be used alone or in a mixture of two or more. The dispersant may be used in an amount of 0.1 to 100 wt%, for example, 10 to 20 wt%, based on the solid content of the light conversion material such as quantum dots.

The binder resin may include an acrylic resin, an epoxy resin, or a combination thereof.

The acrylic resin is a copolymer of a first ethylenically unsaturated monomer and a second ethylenically unsaturated monomer copolymerizable therewith, and may be a resin comprising at least one acrylic repeating unit.

The first ethylenically unsaturated monomer is an ethylenically unsaturated monomer containing at least one carboxyl group, and examples of the monomer include acrylic acid, methacrylic acid, maleic acid, itaconic acid, fumaric acid, or a combination thereof.

The first ethylenically unsaturated monomer may be included in an amount of 5 to 50 wt%, for example 10 to 40 wt%, based on the total amount of the acrylic binder resin.

The second ethylenically unsaturated monomer may be an aromatic vinyl compound such as styrene, alpha-methylstyrene, vinyltoluene, vinylbenzyl methyl ether, or the like; unsaturated carboxylic acid ester compounds such as methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, benzyl (meth) acrylate, cyclohexyl (meth) acrylate, phenyl (meth) acrylate, and the like; unsaturated aminoalkyl carboxylate compounds such as 2-aminoethyl (meth) acrylate, 2-dimethylaminoethyl (meth) acrylate, and the like; vinyl carboxylate compounds such as vinyl acetate, vinyl benzoate and the like; unsaturated glycidyl carboxylate compounds such as glycidyl (meth) acrylate and the like; vinyl cyanide compounds such as (meth) acrylonitrile and the like; unsaturated amide compounds such as (meth) acrylamide and the like; and the like, and the second ethylenically unsaturated monomer may be used alone or as a mixture of two or more.

Specific examples of the acrylic resin may be polymethyl methacrylate, a (meth) acrylic acid/benzyl methacrylate copolymer, a (meth) acrylic acid/benzyl methacrylate/styrene copolymer, a (meth) acrylic acid/benzyl methacrylate/2-hydroxyethyl methacrylate copolymer, a (meth) acrylic acid/benzyl methacrylate/styrene/2-hydroxyethyl methacrylate copolymer, and the like, but are not limited thereto, and the acrylic resin may be used alone or as a mixture of two or more.

The weight average molecular weight of the acrylic binder resin may be 1,000g/mol to 15,000 g/mol. When the weight average molecular weight of the acrylic binder resin is within the range, close contact property with the substrate, physical property and chemical property are improved, and viscosity is appropriate.

The epoxy resin may be a thermally polymerizable monomer or oligomer, and may include compounds having carbon-carbon unsaturated bonds and carbon-carbon ring bonds.

The epoxy resin may include bisphenol a epoxy resin, bisphenol F epoxy resin, phenol novolac epoxy resin, cyclic aliphatic epoxy resin, and aliphatic polyglycidyl ether, in addition to the compounds of chemical formula 1 and chemical formula 2, but is not limited thereto.

As a commercially available product of the Epoxy resin, it may be a bis-phenyl Epoxy resin, such as YX4000, YX4000H, YL6121H, YL6640 or YL6677 of YukaShell Epoxy Co; examples of the cresol novolak epoxy resin include EOCN-102, EOCN-103S, EOCN-104S, EOCN-1020, EOCN-1025 and EOCN-1027 from Nippon Kayaku Co. Ltd., and Eiboket (EPIKOTE)180S75 from Eyaka shell epoxy Co., Ltd. In addition to these, the bisphenol a epoxy resin may be abbott 1001, 1002, 1003, 1004, 1007, 1009, 1010, and 828 of yujia shell epoxy; the bisphenol F epoxy resin may be Aibicott 807 and 834 from Uyga shell epoxy company; the phenol novolac epoxy resin may be iboket 152, 154 or 157H65 from yujia shell epoxy company and EPPN201, 202 from japan chemie ltd; the cyclic aliphatic epoxy resin may be CY175, CY177 and CY179 from Ciba-GEIGY A.G Corp., company ERL-4234, ERL-4299, ERL-4221 and ERL-4206 from U.C. company, Xiudaidin (Showdyne)509 from Showa Denko K.K, Elonga (Araldite) CY-182, CY-192 and CY-184 from Ciba, Albizin (Dainippon Ink and Chemicals Inc.) Albiz 200 and 400 from Dainippon Ink Chemicals, Eja-Kett corporation, Eja-Kett-corporation and Seelanius coatings (Celanese Coogine coatings) EP1032H60, ED-5661 and ED-5662; the aliphatic polyglycidyl ethers may be ibiocide 190P and 191P from ewga shell epoxy, epellite (EPOLITE)100MF from Kyoeisha Yushi Kagaku kogyo, Ltd, ebriol (epilo) TMP from Nihon Yushi K.K, and the like.

The reactive unsaturated compounds can be used with monomers or oligomers commonly used in conventional photocurable and thermosetting compositions.

The reactive unsaturated compound may be an acrylate-based compound. For example, it may be selected from ethylene glycol diacrylate, triethylene glycol diacrylate, 1, 4-butanediol diacrylate, 1, 6-hexanediol diacrylate, neopentyl glycol diacrylate, pentaerythritol triacrylate, dipentaerythritol diacrylate, dipentaerythritol triacrylate, dipentaerythritol pentaacrylate, at least one of pentaerythritol hexaacrylate, bisphenol a dipropylene glycol ester, trimethylolpropane triacrylate, novolac epoxy acrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, propylene glycol dimethacrylate, 1, 4-butanediol dimethacrylate, 1, 6-hexanediol dimethacrylate, etc., which may be used alone or in a mixture of two or more.

The reactive unsaturated compound may be treated with an anhydride to improve developability.

The quantum dot containing layer may further comprise a diffusing agent.

For example, the diffusant may comprise barium sulfate (BaSO)₄) Calcium carbonate (CaCO)₃) Titanium dioxide (TiO)₂) Zirconium oxide (ZrO)₂) Or a combination thereof.

The diffusing agent reflects light that is not absorbed in the quantum dots, so that the reflected light can be absorbed again in the quantum dots. In other words, the diffusing agent increases the dose of light absorbed in the quantum dots, and thus may increase the light conversion efficiency of the curable composition.

The diffuser can have an average particle size (e.g., D) of 150nm to 250nm, such as 180nm to 230nm₅₀). When the average particle diameter of the diffusing agent is within the range, more excellent light diffusing effect can be obtained and light conversion efficiency can be improved.

In order to improve the stability and dispersibility of the quantum dots, the quantum dot-containing layer may further include a thiol-based additive.

The thiol-based additive may replace the shell surface of the quantum dot, and may improve dispersion stability of the quantum dot in a solvent and may stabilize the quantum dot.

The thiol-based additive may have 2 to 10, for example, 2 to 4 thiol groups (-SH) at the end according to its structure.

For example, the thiol-based additive may include at least two functional groups represented by chemical formula 3 at the end.

[ chemical formula 3]

In the chemical formula 3, the first and second,

L⁷and L⁸Each independently a single bond, a substituted or unsubstituted C1 to C10 alkylene, a substituted or unsubstituted C3 to C20 cycloalkylene, a substituted or unsubstituted C6 to C20 arylene, or a substituted or unsubstituted C2 to C20 heteroarylene.

For example, the thiol-based additive may be represented by chemical formula 4.

[ chemical formula 4]

In the chemical formula 4, the first and second organic solvents,

L⁷and L⁸Each independently a single bond, a substituted or unsubstituted C1 to C20 alkylene, a substituted or unsubstituted C3 to C20 cycloalkylene, a substituted or unsubstituted C6 to C20 arylene, or a substituted or unsubstituted C2 to C20 heteroarylene, and

u1 and u2 are each independently an integer of 0 or 1.

For example, in

chemical formulas

3 and 4, L⁷And L⁸Each independently may be a single bond or a substituted or unsubstituted C1 to C20 alkylene group.

Specific examples of the thiol-based additive may be selected from pentaerythritol tetrakis (3-mercaptopropionate) represented by chemical formula 3a, trimethylolpropane tris (3-mercaptopropionate) represented by chemical formula 3b, pentaerythritol tetrakis (mercaptoacetate) represented by chemical formula 3c, trimethylolpropane tris (2-mercaptoacetate) represented by chemical formula 3d, glycol di-3-mercaptopropionate represented by chemical formula 3e, and combinations thereof.

[ chemical formula 3a ]

[ chemical formula 3b ]

[ chemical formula 3c ]

[ chemical formula 3d ]

[ chemical formula 3e ]

The quantum dot containing layer may further comprise a polymerization inhibitor comprising a hydroquinone based compound, a catechol based compound, or a combination thereof. By further comprising a hydroquinone-based compound, a catechol-based compound, or a combination thereof, the quantum dot-containing layer can suppress crosslinking at room temperature during exposure after coating of the composition comprising quantum dots.

For example, the hydroquinone-based compound, the catechol-based compound, or the combination thereof may be hydroquinone, methylhydroquinone, methoxyhydroquinone, t-butylhydroquinone, 2, 5-di-t-butylhydroquinone, 2, 5-bis (1, 1-dimethylbutyl) hydroquinone, 2, 5-bis (1,1,3, 3-tetramethylbutyl) hydroquinone, catechol, t-butylcatechol, 4-methoxyphenol, pyrogallol, 2, 6-di-t-butyl-4-methylphenol, 2-naphthol, tris (N-hydroxy-N-nitrosophenylamino-O, O') aluminum, or a combination thereof, but is not necessarily limited thereto.

The quantum dot containing layer may contain malonic acid in addition to the thiol-based additive and the polymerization inhibitor; 3-amino-1, 2-propanediol; a silane-based coupling agent; leveling agent; a fluorine-based surfactant; or a combination thereof.

For example, the quantum dot containing layer may further include a silane-based coupling agent having a reactive substituent (e.g., vinyl group, carboxyl group, methacryloxy group, isocyanate group, epoxy group, etc.) to improve the close contact property with the substrate.

Examples of the silane-based coupling agent may be trimethoxysilylbenzoic acid, gamma-methacryloxypropyltrimethoxysilane, vinyltriacetoxysilane, vinyltrimethoxysilane, gamma-isocyanatopropyltriethoxysilane, gamma-glycidoxypropyltrimethoxysilane, beta- (epoxycyclohexyl) ethyltrimethoxysilane, etc., and these silane-based coupling agents may be used alone or in a mixture of two or more.

In addition, the quantum dot containing layer may further contain a surfactant (e.g., a fluorine-based surfactant) as necessary to improve the coating properties and suppress the generation of spots.

An example of the fluorine-based surfactant may be

And

(BM Chemieinc, BM) Chemienc); meijia Method (MEGAFACE) F

F

F

And F

(Dainippon Ink chemical industry Co., Ltd. (Dainippon Ink Kagaku Kogyo Co., Ltd.)); florade (FULORAD)

Florad

Florad

And Florad

(Sumitomo 3M Co., Ltd.); shafulon (SURFLON)

Shafulong (a medicine for treating diabetes)

Shafulong (a medicine for treating diabetes)

Shafulong (a medicine for treating diabetes)

And saflufon

(Asahi Glass Co., Ltd.); and

and

etc. (Toray Silicone co., Ltd.)); f-482, F-484, F-478, F-554, etc., of Diegon, Inc. (DIC Co., Ltd.).

The quantum dot containing layer may further contain predetermined amounts of other additives (e.g., antioxidants, stabilizers, etc.) as long as they do not reduce the properties.

The method of manufacturing the quantum dot containing layer may include coating a curable composition including the foregoing components on a substrate using an inkjet spray method to form a pattern (S1); and curing the pattern (S2).

(S1) Pattern formation

In the inkjet spray method, the curable composition may be coated on the substrate to a thickness of 0.5 μm to 10 μm. The inkjet spray method can form a pattern by spraying a single color and thus repeating the spraying for the number of times of the desired number of colors, but the pattern can be formed by spraying the desired number of colors at the same time.

(S2) curing

The obtained pattern was cured to obtain a cured resin layer. Herein, the curing may be thermal curing. Thermal curing may be performed by heating the pattern at 100 ℃ or higher for 3 minutes to remove the solvent in the curable composition, and then heating the pattern at a temperature of 160 ℃ to 300 ℃, more preferably 180 ℃ to 250 ℃, for about 30 minutes.

Furthermore, the quantum dot containing layer can be manufactured without ink jetting. Herein, the manufacturing method is performed by coating a curable composition containing the above-described components or the like on a predetermined pre-treated substrate by an appropriate coating method among spin coating, roll coating, spray coating, or the like, for example, to have a thickness of 0.5 μm to 10 μm, and then irradiating light thereto to form a pattern required for a color filter. The irradiation may be performed by using ultraviolet rays, electron beams, or X-rays as a light source, and the ultraviolet rays may be irradiated, for example, within a region of 190nm to 450nm, and specifically 200nm to 400 nm. The irradiation may be performed by further using a photoresist mask. After the irradiation process is performed in this manner, the composition layer exposed to the light source is treated with a developing solution. Herein, the unexposed areas in the composition layer dissolve and form a pattern for the color filter. This process may be repeated as many times as the number of colors required to obtain a color filter having a desired pattern. Further, when the image pattern obtained by the development in the above process is cured by reheating or irradiating actinic rays thereto, crack resistance, solvent resistance, and the like can be improved.

The curable composition may further comprise a solvent.

The solvent may include alcohols such as methanol, ethanol, and the like; glycol ethers such as ethylene glycol methyl ether, ethylene glycol ethyl ether, propylene glycol methyl ether and the like; cellosolves of acetic acid such as methyl cellosolve acetate, ethyl cellosolve acetate, diethyl cellosolve acetate, and the like; carbitols such as methyl ethyl carbitol, diethyl carbitol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, and the like; propylene glycol alkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate and the like; ketones such as methyl ethyl ketone, cyclohexanone, 4-hydroxy-4-methyl-2-pentanone, methyl-n-acetone, methyl-n-butanone, methyl-n-pentanone, 2-heptanone, and the like; saturated aliphatic monocarboxylic acid alkyl esters such as ethyl acetate, n-butyl acetate, isobutyl acetate, and the like; lactates such as methyl lactate, ethyl lactate, and the like; alkyl glycolates such as methyl glycolate, ethyl glycolate, butyl glycolate, etc.; alkoxyalkyl acetates such as methoxymethyl acetate, methoxyethyl acetate, methoxybutyl acetate, ethoxymethyl acetate, ethoxyethyl acetate, and the like; alkyl 3-hydroxypropionates such as methyl 3-hydroxypropionate, ethyl 3-hydroxypropionate and the like; alkyl 3-alkoxypropionates such as methyl 3-methoxypropionate, ethyl 3-ethoxypropionate, methyl 3-ethoxypropionate, etc.; alkyl 2-hydroxypropionates such as methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, propyl 2-hydroxypropionate, and the like; alkyl 2-alkoxypropionates such as methyl 2-methoxypropionate, ethyl 2-ethoxypropionate, methyl 2-ethoxypropionate, etc.; alkyl 2-hydroxy-2-methylpropionates such as methyl 2-hydroxy-2-methylpropionate, ethyl 2-hydroxy-2-methylpropionate and the like; alkyl 2-alkoxy-2-methylpropionates such as methyl 2-methoxy-2-methylpropionate, ethyl 2-ethoxy-2-methylpropionate and the like; esters such as 2-hydroxyethyl propionate, 2-hydroxy-2-methylethyl propionate, hydroxyethyl acetate, methyl 2-hydroxy-3-methylbutyrate, and the like; or ketoesters such as ethyl pyruvate, etc., and may additionally be N-methylformamide, N-dimethylformamide, N-methylformanilide, N-methylacetamide, N-dimethylacetamide, N-methylpyrrolidone, dimethyl sulfoxide, benzylethyl ether, dihexyl ether, acetylacetone, isophorone, hexanoic acid, octanoic acid, 1-octanol, 1-nonanol, benzyl alcohol, benzyl acetate, ethyl benzoate, diethyl oxalate, diethyl maleate, γ -butyrolactone, ethylene carbonate, propylene carbonate, phenylcellosolve acetate, dimethyl adipate, etc., but is not limited thereto.

For example, the solvent may desirably be a glycol ether, such as ethylene glycol monoethyl ether, or the like; ethylene glycol alkyl ether acetates such as ethyl cellosolve acetate and the like; esters such as ethyl 2-hydroxypropionate and the like; carbitols such as diethylene glycol monomethyl ether and the like; propylene glycol alkyl ether acetates such as propylene glycol monomethyl ether acetate, propylene glycol propyl ether acetate and the like; alcohols, such as ethanol, and the like, or combinations thereof.

For example, the solvent may include propylene glycol monomethyl ether acetate, dipropylene glycol methyl ether acetate, ethanol, ethylene glycol dimethyl ether, ethylene glycol methyl ethyl ether, diethylene glycol dimethyl ether, dimethylacetamide, 2-butoxyethanol, N-methylpyrrolidine, N-ethylpyrrolidine, propylene carbonate, γ -butyrolactone, dimethyl adipate, or a combination thereof.

The balance of solvent may be included based on the total amount of curable composition.

Hereinafter, the present invention is described in more detail with reference to examples. However, these examples should not be construed in any way as limiting the scope of the invention.

(confirmation of the Spectrum of the light Source, pressure-sensitive adhesive layer, and blue Filter layer)

As shown in fig. 3, a light source that emits light at a wavelength of 400nm to 500nm and i) the light intensity at a wavelength of 420nm is less than 3% of the maximum light intensity is used as the light source 1, and another light source that emits light at a wavelength of 400nm to 500nm but ii) the light intensity at a wavelength of 420nm is greater than or equal to 3% of the maximum light intensity is used as the light source 2. Specifically, for light source 1, the light intensity at a wavelength of 420nm (about 0.01) is about 1% of the maximum light intensity, and for light source 2, the light intensity at a wavelength of 420nm (about 0.05) is about 5% of the maximum light intensity.

As shown in fig. 4, i) a pressure-sensitive adhesive layer having an absorptivity of less than 50% at a wavelength of 420nm is used as the pressure-sensitive adhesive layer 1, and ii) another pressure-sensitive adhesive layer having an absorptivity of greater than or equal to 50% at a wavelength of 420nm is used as the pressure-sensitive adhesive layer 2.

As shown in fig. 5, i) a blue filter layer having an absorptance of less than 50% at a wavelength of 420nm is used as the blue filter layer 1, and ii) another blue filter layer having an absorptance of greater than or equal to 50% at a wavelength of 420nm is used as the blue filter layer 2.

(production of display device)

Example 1

A display device having a structure of light source/quantum dot-containing layer/pressure-sensitive adhesive layer/blue filter layer was manufactured using the light source 2, InP/ZnSe/ZnS quantum dots, pressure-sensitive adhesive layer 2, and blue filter layer 1.

Example 2

A display device was manufactured according to the same method as example 1, except that the pressure-sensitive adhesive layer 1 was used instead of the pressure-sensitive adhesive layer 2, and the blue filter layer 2 was used instead of the blue filter layer 1.

Example 3

A display device was manufactured according to the same method as example 1, except that the blue filter layer 2 was used instead of the blue filter layer 1.

Comparative example 1

A display device was manufactured according to the same method as example 1, except that the light source 1 was used instead of the light source 2, and the pressure-sensitive adhesive layer 1 was used instead of the pressure-sensitive adhesive layer 2.

Comparative example 2

A display device was manufactured according to the same method as example 1, except that the pressure-sensitive adhesive layer 1 was used instead of the pressure-sensitive adhesive layer 2.

(measurement of the ultimate intensity of light)

In the display devices of examples 1 and 2 and comparative example 2, the final intensity of light emitted from the light source was measured by using SR-3, and the result is shown in fig. 6. Referring to fig. 6, the display devices of examples 1 and 2 exhibited an intensity of light at a wavelength of 420nm of less than or equal to 1% of the maximum intensity of the light after the light was emitted from the light source and passed through the quantum dot containing layer, the pressure-sensitive adhesive layer, and the blue filter layer, but the display device of comparative example 2 exhibited an intensity of light at a wavelength of 420nm of more than 1% of the maximum intensity of the light after the light was emitted from the light source and passed through the quantum dot containing layer, the pressure-sensitive adhesive layer, and the blue filter layer. Specifically, for each of the display devices of example 1 and example 2, the intensity (0.2) of light at a wavelength of 420nm after the light is emitted from the light source and passed through the quantum dot containing layer, the pressure-sensitive adhesive layer, and the blue filter layer was about 0.51% of the maximum intensity (39) of light, but for the display device of comparative example 2, the intensity (0.42) of light at a wavelength of 420nm after the light is emitted from the light source and passed through the quantum dot containing layer, the pressure-sensitive adhesive layer, and the blue filter layer was about 1.03% of the maximum intensity (40.5) of light.

(measurement of color purity and Brightness)

Color purity and luminance of light emitted from the display devices according to examples 1 to 3 and comparative examples 1 and 2 were measured. Specifically, its color purity with respect to the C light source was measured by using a spectrophotometer (MCPD3000, tsukakamur electronics co., Ltd.), and in addition, its luminance (Y) was calculated with reference to CIE color coordinates, and the results are shown in table 1.

(Table 1)

	CIE color coordinate (Bx)	Luminance (%)
			Example 1	0.152	105
Example 2	0.152	105
			Example 3	0.151	96
Comparative example 1	0.152	100
			Comparative example 2	0.158	108

Referring to table 1, comparative example 1 can achieve high color reproducibility as compared to those of examples 1 and 2 but shows a problem of luminance degradation, and comparative example 2 can achieve improved luminance as compared to those of examples 1 and 2 but cannot achieve high color reproducibility. Further, with example 3, when the pressure-sensitive adhesive layer and the blue filter layer have an absorbance of 50% or more at a wavelength of 420nm or less, high color reproducibility can be achieved, but a problem of severe luminance deterioration is exhibited.

While the invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not to be limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. The above-described embodiments are therefore to be understood as illustrative and not restrictive in any way.

Claims

1. A display device, comprising:

a light source configured to emit light at a wavelength of 400nm to 500nm and a light intensity at a wavelength of 420nm is greater than or equal to 3% of a maximum light intensity of the light source;

a quantum dot containing layer disposed on the light source;

a pressure-sensitive adhesive layer disposed on the quantum dot containing layer; and

a blue filter layer disposed on the pressure-sensitive adhesive layer,

wherein an intensity of light at a wavelength of 420nm after the light from the light source passes through the quantum dot containing layer, the pressure-sensitive adhesive layer, and the blue filter layer is less than or equal to 1% of a maximum intensity of the light.

2. The display device of claim 1, wherein one of the pressure-sensitive adhesive layer and the blue filter layer has an absorbance of less than 50% at a wavelength of less than or equal to 420 nm.

3. The display device according to claim 2, wherein the pressure-sensitive adhesive layer has an absorbance of greater than or equal to 50% at a wavelength of less than or equal to 420 nm.

4. The display device of claim 2, wherein the blue filter layer has an absorbance of greater than or equal to 50% at wavelengths less than or equal to 420 nm.

5. The display device according to claim 1, wherein the pressure-sensitive adhesive layer or the blue filter layer contains one or more of an azo-based dye, an azomethine-based dye, and a porphyrin-based dye.

6. The display device according to claim 5, wherein the azomethine-based dye is represented by chemical formula 1:

[ chemical formula 1]

Wherein, in chemical formula 1,

m is Zn, Co, Cu or V,

X¹to X⁴Each independently an oxygen atom or a sulfur atom,

n1 to n4 are each independently an integer from 0 to 4.

7. The display device according to claim 6, wherein the azomethine-based dye represented by chemical formula 1 is represented by one of chemical formulae 1-1 to 1-7:

[ chemical formula 1-1]

[ chemical formulas 1-2]

[ chemical formulas 1-3]

[ chemical formulas 1 to 4]

[ chemical formulas 1 to 5]

[ chemical formulas 1 to 6]

[ chemical formulas 1 to 7]

8. The display device according to claim 5, wherein the porphyrin-based dye is represented by chemical formula 2:

[ chemical formula 2]

Wherein, in chemical formula 2,

m is Zn, Co, Cu or V,

R⁵to R¹²Each independently a halogen atom,A substituted or unsubstituted C1 to C20 alkyl group, a substituted or unsubstituted C1 to C20 alkoxy group, a substituted or unsubstituted C6 to C20 aryl group, a sulfonic acid group, a substituted or unsubstituted sulfonamide group, or a substituted or unsubstituted C1 to C20 alkyl ester group,

9. The display device according to claim 8, wherein the porphyrin-based dye represented by chemical formula 2 is represented by one of chemical formula 2-1 to chemical formula 2-20:

[ chemical formula 2-1]

[ chemical formula 2-2]

[ chemical formulas 2-3]

[ chemical formulas 2-4]

[ chemical formulas 2 to 5]

[ chemical formulas 2 to 6]

[ chemical formulae 2 to 7]

[ chemical formulas 2 to 8]

[ chemical formulas 2 to 9]

[ chemical formulas 2-10]

[ chemical formulas 2 to 11]

[ chemical formulas 2-12]

[ chemical formulas 2-13]

Wherein, in chemical formulas 2 to 13,

[ chemical formulae 2 to 14]

[ chemical formulas 2 to 15]

[ chemical formulas 2 to 16]

[ chemical formulas 2 to 17]

[ chemical formulas 2 to 18]

[ chemical formulae 2 to 19]

[ chemical formulas 2-20]

10. The display device of claim 1, wherein the quantum dots comprise green quantum dots, red quantum dots, or a combination thereof.

11. The display device according to claim 1, wherein the display device further comprises a liquid crystal layer between the pressure-sensitive adhesive layer and the blue filter layer.

12. The display device of claim 11, wherein the display device further comprises an overcoat layer between the liquid crystal layer and the blue filter layer.

13. The display device of claim 1, wherein the quantum dot containing layer further comprises a diffusing agent.

14. The display device of claim 13, wherein the diffusing agent comprises barium sulfate, calcium carbonate, titanium dioxide, zirconium oxide, or a combination thereof.