KR20230122869A - A light conversion ink composition, a light converting laminating unit manufactured using the same, a backlight unit, a light converting pixel unit and an image display device - Google Patents

Abstract

The present invention relates to a light conversion ink composition comprising light emitting particles, a photopolymerizable monomer and an antioxidant; A light conversion laminated substrate manufactured using the light conversion ink composition and a backlight unit including the same; a photoconversion pixel substrate prepared using the photoconversion ink composition; and an image display device including the backlight unit or the light conversion pixel substrate.

Description

Photoconversion ink composition, photoconversion laminated substrate manufactured using the same, backlight unit, photoconversion pixel substrate, and image display device PIXEL UNIT AND AN IMAGE DISPLAY DEVICE}

The present invention relates to a photoconversion ink composition, a photoconversion laminated substrate, a backlight unit, and a photoconversion pixel substrate used in an image display device.

As we enter the full-fledged information age, the demand for image display devices is increasing in various forms. Recently, various types of display devices such as a liquid crystal display (LCD), a plasma display panel (PDP), and an organic light emitting diode display device (OLED) are being utilized. .

The color gamut is one of the indicators representing the performance of a display device, and it can be generally considered that the higher the color gamut, the more realistic colors are reproduced. Recently, as a method for increasing the color gamut of a display device, research is being conducted to use a quantum dot in addition to using a blue LED instead of a normal white LED. Quantum dots, which emit light as electrons in an unstable state descend from a conduction band to a valence band, generate strong fluorescence because they have a very large extinction coefficient and excellent quantum yield. In addition, since the emission wavelength changes according to the size of the quantum dots, light in the entire visible light range can be obtained by adjusting the size of the quantum dots.

When a color filter to which a light conversion pixel is applied is manufactured using a composition including such quantum dots, the light conversion efficiency can be improved and the color reproducibility can be increased. At this time, when the color filter is manufactured using the photolithography method, the color filter has the advantage of excellent precision and reproducibility, but the coating, exposure, development, and curing process for pixel formation are required for each color, which increases manufacturing time and cost. And the manufacturing process is complicated, so there is a problem that yield management is difficult.

An inkjet method proposed to solve these problems is a technique of implementing an image in which each ink is colored by jetting liquid ink to a predetermined location using an inkjet head. Using the inkjet method, a plurality of colors including red, green, and blue can be colored at once, so that manufacturing time and cost can be greatly reduced, as well as the manufacturing process can be simplified.

In this regard, Korean Patent Publication No. 10-2021-0080923 (patent document 1 described later) describes a quantum dot solution composition with minimized quantum efficiency degradation, and Korean Patent Registration No. 10-2284582 (patent document 1 described later). Although Document 2) discloses a technology related to a red photosensitive resin composition with improved chemical resistance, the color filter manufactured using the composition has poor light conversion efficiency and insufficient light resistance and reliability, resulting in poor inkjet printing process efficiency. there is a problem.

Republic of Korea Patent Publication No. 10-2021-0080923 Republic of Korea Patent Registration No. 10-2284582

An object of the present invention is to provide a light conversion ink composition excellent in light conversion efficiency, light fastness, reliability and continuous jetting property in order to solve the problems of the prior art.

Another object of the present invention is to provide a light conversion laminated substrate manufactured using the light conversion ink composition and a backlight unit including the same.

In addition, an object of the present invention is to provide a photoconversion pixel substrate manufactured using the photoconversion ink composition.

Another object of the present invention is to provide an image display device including the backlight unit or the light conversion pixel substrate.

However, the problem to be solved by the present invention is not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

The present invention, light-emitting particles; photopolymerization monomer; And it relates to a light conversion ink composition comprising an antioxidant.

In addition, the present invention relates to a light conversion laminated substrate manufactured using the light conversion ink composition and a backlight unit including the same.

In addition, the present invention relates to a photoconversion pixel substrate manufactured using the photoconversion ink composition.

In addition, the present invention relates to an image display device including the backlight unit or the light conversion pixel substrate.

According to the present invention, by adjusting the content of a specific antioxidant or the like in the composition, it has an effect of manufacturing a light conversion ink composition with improved light conversion efficiency, light resistance and reliability.

In addition, according to the light conversion ink composition according to the present invention, the continuous jetting property may be improved compared to the prior art.

In addition, the light conversion laminated substrate manufactured using the light conversion ink composition according to the present invention may have improved coating film uniformity compared to the prior art.

The present invention relates to a light conversion ink composition comprising light emitting particles, a photopolymerizable monomer, and an antioxidant; A light conversion laminated substrate prepared using the light conversion ink composition and a backlight unit including the same; a photoconversion pixel substrate prepared using the photoconversion ink composition; and an image display device including the backlight unit and the light conversion pixel substrate.

Specifically, the light conversion ink composition of the present invention includes 0.2 to 8% by weight of a sulfur-based antioxidant based on the total weight of the solid content of the light conversion ink composition and contains 4 to 12% by weight of an antioxidant, thereby improving light conversion efficiency and light resistance. , Reliability and continuous jetting properties are extremely improved, and furthermore, the film uniformity is improved.

Hereinafter, the present invention will be described in detail.

<Photoconversion ink composition>

The light conversion ink composition of the present invention includes light-emitting particles, a photopolymerization monomer, and an antioxidant, and may further include one or more of scattering particles, a photopolymerization initiator, and additives.

luminescent particles

The light-emitting particles of the present invention may emit light of a wavelength different from the absorbed wavelength by absorbing light in a certain wavelength range, but is not limited thereto. The light emitting particles of the present invention may be red light emitting particles emitting light (red light) having a peak emission wavelength in the range of 605 nm to 665 nm, and green light emitting particles emitting light (green light) having a peak emission wavelength in the range of 500 nm to 600 nm. It may be particles, and may be blue light-emitting particles that emit light (blue light) having a peak emission wavelength in the range of 420 nm to 480 nm. The light conversion composition of the present invention includes at least one of the light-emitting particles.

The quantum dots in the present invention have a core-shell structure including a core and a shell covering at least a portion of the core. This structure may be a core-shell structure composed of a core and a first shell, or may be a core-shell-shell structure composed of a core, first shell, and second shell.

The quantum dot is not particularly limited as long as it is a quantum dot particle capable of emitting light when stimulated by light or electricity. For example, II-VI group semiconductor compounds; Group III-V semiconductor compounds; Group IV-VI semiconductor compounds; Group IV elements or compounds containing them; And it may be selected from the group consisting of combinations thereof, which may be used alone or in combination of two or more.

For example, the II-VI group semiconductor compound is a binary element compound selected from the group consisting of CdS, CdSe, CdTe, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, and mixtures thereof; CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, and mixtures thereof; and CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSTe, HgZnSeS, HgZnSeTe, HgZnSTe, and a quaternary compound selected from the group consisting of mixtures thereof, but is not limited thereto.

The group III-V semiconductor compound is a binary element compound selected from the group consisting of GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, and mixtures thereof; A ternary compound selected from the group consisting of GaNP, GaNAs, GaNSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, and mixtures thereof; And it may be selected from the group consisting of quaternary compounds selected from the group consisting of GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlNSb, InAlPAs, InAlPSb, and mixtures thereof. It is not limited.

The group IV-VI semiconductor compound is a binary element compound selected from the group consisting of SnS, SnSe, SnTe, PbS, PbSe, PbTe, and mixtures thereof; a ternary compound selected from the group consisting of SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbTe, and mixtures thereof; And SnPbSSe, SnPbSeTe, SnPbSTe, and may be at least one selected from the group consisting of quaternary compounds selected from the group consisting of mixtures thereof, but is not limited thereto either.

Although not limited thereto, the group IV element or a compound containing the same may be an element selected from the group consisting of Si, Ge, and mixtures thereof; And it may be selected from the group consisting of a binary element compound selected from the group consisting of SiC, SiGe, and mixtures thereof.

Quantum dots are homogeneous unitary structures; dual structures such as a core-shell structure and a gradient structure; Or it may be a mixed structure thereof, and in the present invention, quantum dots are not particularly limited as long as they can emit light when stimulated by light.

According to an embodiment, the quantum dot has a core-shell structure, and the core includes InP, InZnP, InGaP, CdSe, CdS, CdTe, ZnS, ZnSe, ZnTe, CdSeTe, CdZnS, CdSeS, PbSe, PbS, PbTe, AgInZnS, It includes at least one selected from the group consisting of HgS, HgSe, HgTe, GaN, GaP, GaAs, InGaN, InAs, and ZnO, and the shell is ZnS, ZnSe, ZnTe, ZnO, CdS, CdSe, CdTe, CdO, InP , InS, GaP, GaN, GaO, InZnP, InGaP, InGaN, InZnSCdSe, PbS, TiO, may include one or more selected from the group consisting of SrSe and HgSe, preferably, InP / ZnS, InP / ZnSe , InP/GaP/ZnS, InP/ZnSe/ZnS, InP/ZnSeTe/ZnS, and InP/MnSe/ZnS.

According to an exemplary embodiment, the core includes a quaternary compound of silver (Ag), indium (In), gallium (Ga), and sulfur (S). For example, the core is AgInGaS. Such a core has an advantage of more efficiently absorbing a short-wavelength light source and minimizing the light absorption rate of the light emitting region, so that excellent light conversion efficiency can be expected even with a small content.

The shell includes at least two elements of In, Ga, and S, and may include, for example, GaS. At this time, in the present invention, the shell functions to improve color purity by suppressing the trap emission of the core and maintaining a narrow half width of the emission wavelength.

According to an exemplary embodiment, the quantum dot of the core-shell structure may include AgInGaS/GaS, etc., but is not limited thereto.

In some embodiments, the present invention may further include a quantum dot having a structure other than the core-shell structure described above, if necessary. For example, a core-shell quantum dot such as InP/ZnSe/ZnS, InP/ZnS, InGaP/ZnS, or InGaP/ZnSe/ZnS may be further included, but is not limited thereto.

The quantum dots may be synthesized by a wet chemical process, a metal organic chemical vapor deposition (MOCVD) process, or a molecular beam epitaxy (MBE) process, but are not limited thereto. , Preferably, it is possible to obtain quantum dots having excellent optical properties when synthesized by a wet chemical process.

The wet chemical process is a method of growing particles by putting a precursor material in an organic solvent. When the crystal grows, the organic solvent is naturally coordinated on the surface of the quantum dot crystal and acts as a dispersant to control the growth of the crystal, so it is easier and cheaper than vapor deposition methods such as organometallic chemical vapor deposition or molecular beam epitaxy to produce nano Since the growth of the particles can be controlled, it is preferred to prepare the quantum dots using the wet chemical process.

In the present invention, the light-emitting particles may be included in an amount of 3 to 50% by weight, preferably 5 to 45% by weight, and more preferably 8 to 40% by weight, based on the total weight of the solid content in the light conversion ink composition. When the light emitting particles are included within the above range, light conversion efficiency may be improved.

In the present invention, the solid content refers to components other than the solvent of the light conversion ink composition.

When the content of the light emitting particles is less than the above range, light conversion efficiency is lowered, making it difficult to implement a high-quality display device. In addition, if the content exceeds the above range, the productivity of the post-production process of the display and the reliability of the product may be reduced due to insufficient curing of the coating film due to lack of components that implement curing.

photopolymerization monomer

The photopolymerization monomer of the present invention improves the dispersibility of light-emitting particles, thereby enabling the implementation of a low-viscosity light conversion composition of 80 cP or less without a solvent. Accordingly, the light conversion composition according to the present invention can be effectively used to manufacture a light conversion laminated board.

In particular, the photopolymerization monomer of the present invention preferably includes a monomer derived from succinic acid in terms of improving the dispersibility of light emitting particles, specifically mono-2-(acryloyloxy)ethyl succinic acid {mono-2-( acryloyloxy)ethyl succinate} and mono-methyl hydrogen succinate, but may be one or more selected from, but is not limited thereto.

On the other hand, the photopolymerizable monomer is preferably included in an amount of 1 to 7% by weight based on the total solid weight of the light conversion ink composition in terms of increasing the degree of polymerization and improving reliability and light conversion efficiency.

The photopolymerizable compound of the present invention may further include a commonly used polymerizable compound. Examples thereof include monofunctional monomers, bifunctional monomers, and other polyfunctional monomers, and among these, bifunctional monomers are preferably used. In addition, in the present invention, it can be confirmed that by mixing a monofunctional monofunctional group to increase the degree of polymerization, it has a good effect on improving light conversion efficiency and reliability.

The type of the monofunctional monomer is not particularly limited, and examples thereof include 1,6-hexanediol diacrylate, nonylphenylcarbitol acrylate, 2-hydroxy-3-phenoxypropyl acrylate, and 2-ethylhexylcarboxylate. Bitol acrylate, 2-hydroxyethyl acrylate, N-vinylpyrrolidone, etc. are mentioned.

The type of the bifunctional monomer is not particularly limited, and examples thereof include bis(acryloyloxyethyl) ether of bisphenol A and the like.

The type of the multifunctional monomer is not particularly limited, and examples thereof include trimethylolpropane tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, and propoxylated trimethylolpropane tri(meth)acrylate. )Acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol tri(meth)acrylate, dipentaerythritol penta(meth)acrylate, ethoxylated dipentaerythritol hexa (meth)acrylate, propoxylated dipentaerythritol hexa(meth)acrylate, dipentaerythritol hexa(meth)acrylate, etc. are mentioned.

In this case, when a trifunctional or more functional curable monomer is further included, inkjet characteristics can be obtained when the viscosity of the ink composition is controlled within 80 cP.

The polymerizable monomer may be included in an amount of 25 to 80% by weight, preferably 30 to 75% by weight, based on the total weight of the solid content in the light conversion ink composition. When the polymerizable monomer is included within the above range, there is an advantage in that it is advantageous in controlling the curing degree and can show advantageous results in the application process of the composition. When the polymerizable monomer is included in less than the above range, it becomes difficult to secure fluidity for ink jetting, and when it is included in more than the above range, the content of light emitting particles is insufficient, which may cause a problem of low light efficiency, so included within the above range it is desirable to be

antioxidant

The antioxidant of the present invention may further improve light conversion characteristics or color purity by preventing oxidation of the light conversion ink composition and the coating film formed thereby. Since antioxidants have an effect of improving optical characteristics but are a factor that causes an increase in viscosity, an appropriate mixing ratio of antioxidants is important in order to apply them to inkjet printing. The antioxidant used in the present invention is not particularly limited as long as it can improve the light conversion characteristics or color purity of the light conversion ink composition, but it is preferable to include a sulfur-based antioxidant in terms of light conversion efficiency and light resistance, and the light conversion ink composition Based on the total weight of the solid content, the sulfur-based antioxidant is included in an amount of 0.2 to 8% by weight, and when the antioxidant is included in an amount of less than 4% by weight or more than 12% by weight, viscosity increases and is suitable for application to inkjet printing. There is a problem with not doing it.

The sulfur-based antioxidant of the present invention is thiodiethylene bis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,2-bis({[3-(dodecylthio )propionyl]oxy}methyl)-1,3-propanediyl-bis[3-(dodecylthio)propionate], ditridecyl thiodipropionate, 2-mercaptobenzimidazole, dilauryl- 3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, di(tridecyl) 3,3'-thiodipropionate, distearyl-3,3' - It may be at least one selected from the group consisting of thiodipropionate, pentaerythrityl-tetrakis (3-laurylthiopropionate), and 2-mercaptobenzimidazole. In particular, the sulfur-based antioxidant of the present invention preferably has a bilaterally symmetrical ester group and benzene structure in terms of light conversion characteristics or color purity improvement. As such an antioxidant, at least one selected from commercial products Irganox 1035 (Basf Co.), SONGNOX CS DTDTP (Songwon Co.), AO-412S (Adeka Co.) and AO-503 (Adeka Co.) may be included.

The antioxidant of the present invention may further include at least one selected from phenol-based antioxidants and phosphorus-based antioxidants in addition to the sulfur-based antioxidants.

The antioxidant containing the phenolic compound is 3,9-bis[2-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethoxy] -2,4,8,10-tetraoxaspiro[5.5]undecane, pentaerythrityl tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 1,3,5,-trimethyl-2,4,6,-tris(3'5'-di-t-butyl-4-hydroxybenzyl)benzene, triethylene glycol-bis[3-(3-t- butyl-5-methyl-4-hydroxyphenyl)propionate], 4,4'-thiobis(6-t-butyl-3-methylphenol), tris-(3,5-di-t-butyl- 4-hydroxybenzyl)-isocyanurate, 1,3,5-tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl)-isocyanurate, 1,6-hexanediol -bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2-thio-diethylenebis[3-(3,5-di-t-butyl- 4-hydroxyphenyl) propionate], N,N'-hexamethylenebis(3,5-di-t-butyl-4-hydroxy-hydrocinnamamide), 1,3,5-trimethyl-2, 4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, 2,4-bis[(octylthio)methyl]-O-cresol, 1,6-hexanediol-bis- [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], octadecyl 3-(3,5-di-tert-butyl-4-hydroxyphenol)propionate, 2,2'-methylenebis(4-methyl-6-t-butylphenol), 4,4'-butylidene-bis(3-methyl-6-t-butylphenol), 1,1,3-tris (2-methyl-4-hydroxy-5-t-butylphenyl)butane, 1,3,5-tris(4-hydroxybenzyl)benzene and tetrakis[methylene-3-(3,5′-di- t-butyl-4'-hydroxyphenylpropionate)] may be at least one selected from the group consisting of methane, but is not limited thereto.

The antioxidant containing the phosphorus compound is 3,9-bis(2,6-di-tert-butyl-4-methylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro [5.5] Undecane, diisodecylpentaerythritol diphosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, 2,2'-methylenebis(4,6-di-t- Butyl-1-phenyloxy)(2-ethylhexyloxy)phosphorus, 6-[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propoxy]-2,4,8,10 -Tetra-t-butyldibenz[d,f][1,3,2]dioxaphosphepine, triphenylphosphite, diphenylisodecylphosphite, phenyldiisodecylphosphite, 4,4'-part Thylidene-bis(3-methyl-6-t-butylphenylditridecyl)phosphite, octadecylphosphite, tris(nonylphenyl)phosphite, 9,10-dihydro-9-oxa-10-phosphaphe Nanthrene-10-oxide, 10-(3,5-di-t-butyl-4-hydroxybenzyl)-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, 10 -decyloxy-9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide, tris(2,4-di-t-butylphenyl)phosphite, cyclic neopentane tetraylbis (2,4-di-t-butylphenyl)phosphite, cyclic neopentane tetraylbis(2,6-di-t-butylphenyl)phosphite, 2,2-methylenebis(4,6-di- t-butylphenyl) octylphosphite, tris (2,4-di-t-butylphenyl) phosphite, tetrakis (2,4-di-t-butylphenyl) [1,1-biphenyl] -4, It may be at least one selected from the group consisting of 4'diylbisphosphonite, bis[2,4-bis(1,1-dimethylethyl)-6-methylphenyl]ethyl ester, and phosphonic acid, but is not limited thereto. .

scattering particles

The light conversion ink composition according to the present invention may further include scattering particles.

The scattering particles may use a conventional inorganic material, and preferably may include a metal oxide having an average particle diameter of 50 to 1000 nm.

The metal oxides include Li, Be, B, Na, Mg, Al, Si, K, Ca, Sc, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, Ge, Rb, Sr, Y, Mo, Cs, Ba, La, Hf, W, Tl, Pb, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Ti, Sb, Sn, Zr, Nb, It may be an oxide containing one type of metal selected from the group consisting of Ce, Ta, In, and combinations thereof, but is not limited thereto.

Specifically, Al ₂ O ₃ , SiO ₂ , ZnO, ZrO ₂ , BaTiO ₃ , TiO ₂ , Ta ₂ O ₅ , Ti ₃ O ₅ , ITO, IZO, ATO, ZnO-Al, Nb ₂ O ₃ , SnO, MgO, BaSO ₄ and one selected from the group consisting of combinations thereof is possible. If necessary, a material surface-treated with a compound having an unsaturated bond such as acrylate may also be used.

When the light conversion ink composition according to the present invention includes scattering particles, it is preferable to increase the overall light efficiency in the light conversion coating layer by increasing the path of light emitted from the light emitting particles through the scattering particles. In this aspect, the light conversion ink composition of the present invention preferably includes at least one selected from among TiO ₂ , SiO ₂ , ZnO, and BaSO ₄ as scattering particles.

The scattering particles may have an average particle diameter of 50 to 1000 nm, preferably used in the range of 100 to 500 nm. At this time, if the particle size is too small, sufficient scattering effect of the light emitted from the quantum dots cannot be expected, and on the other hand, if it is too large, it sinks in the composition or the surface of the self-luminous layer of uniform quality cannot be obtained. and use it

The scattering particles may be included in an amount of 0.5 to 20% by weight, preferably 1 to 15% by weight, and more preferably 2 to 10% by weight, based on the total weight of the solid content in the light conversion ink composition. When the scattering particles are included within the above range, it is preferable that the effect of increasing the luminous intensity can be maximized. If the scattering particles are contained within the above range, it may be difficult to obtain the desired luminous intensity, and if the scattering particles exceed the above range, the transmittance of blue irradiation light is significantly reduced, so that the light conversion of the light emitting particles does not work. It is preferable to use it suitably within the said range.

photopolymerization initiator

The light conversion ink composition according to an embodiment of the present invention may further include a photopolymerization initiator.

In one embodiment of the present invention, as long as the photopolymerization initiator can polymerize the polymerizable monomer, its kind may be used without particular limitation. For example, the photopolymerization initiator is an acetophenone-based compound, a benzophenone-based compound, a triazine-based compound, a biimidazole-based compound, an oxime-based compound, a tea in terms of polymerization characteristics, initiation efficiency, absorption wavelength, availability, price, etc. It is preferable to use at least one compound selected from the group consisting of oxanthone-based compounds and phosphine oxide compounds.

For example, for thick film curing of 5 μm or more, using an oxime-based compound or a phosphine oxide compound can secure better physical properties in terms of cured density and surface roughness of the cured film.

Specific examples of the oxime-based compound include o-ethoxycarbonyl-α-oxyimino-1-phenylpropan-1-one, and Irgacure OXE 01 and OXE 02 commercially available from BASF are representative.

Specific examples of the phosphine oxide compound include trimethylbenzoylphenylphosphine oxide, Irgacure 819 from BASF, Darocur TPO, and Lucirin TPO.

The photopolymerization initiator may be included in an amount of 0.2 to 3.0% by weight, preferably 0.3 to 2.5% by weight, based on the total weight of the solid content in the light conversion ink composition. When the photopolymerization initiator is included within the above range, the photoconversion ink composition is highly sensitive and the exposure time is shortened, which is preferable because productivity can be improved. If the photopolymerization initiator is included in an amount less than the above range, sufficient hardness cannot be obtained due to lack of curing by light. If the photopolymerization initiator is included in an amount exceeding the above range, the decrease in light conversion efficiency of the light emitting particles due to the photopolymerization initiator increases rapidly, resulting in the desired emission of light. Since there is a problem of not being able to obtain strength, using it within the above range has the advantage of improving the strength of the pixel portion and the smoothness of the surface of the pixel portion.

In addition, a photopolymerization initiator may be appropriately added to the photopolymerization initiator and used within a range not impairing the effects of the present invention. The use of this is preferable because the composition becomes more sensitive and productivity is improved. As the photopolymerization initiation aid, one or more compounds selected from the group consisting of carboxylic acid and sulfonic acid compounds may be preferably used. In addition, there are cases in which a light absorber may be additionally used.

additive

In addition to the above components, the light conversion ink composition according to an embodiment of the present invention may further include additives such as a surfactant and an adhesion promoter in order to improve flatness or adhesion of a coating film.

When the light conversion ink composition according to the present invention includes the surfactant, there is an advantage in that coating film flatness can be improved. For example, the surfactant is FL-3600 (BASF), BM-1000/BM-1100 (BM Chemie), Proride FC-135/FC-170C/FC-430 (Sumitomo 3M Co., Ltd.), SH-28PA/SH Fluorine-based surfactants such as -190/SH-8400/SZ-6032 (Toray Silicone Co., Ltd.) may be used, but are not limited thereto.

The adhesion promoter may be added to increase adhesion with the substrate, and may include a silane coupling agent having a reactive substituent selected from the group consisting of a carboxyl group, a methacryloyl group, an isocyanate group, an epoxy group, and combinations thereof, but It is not limited. Additives can be used alone or in combination of two or more.

The additive may be used in an amount of 0.01 to 10% by weight, specifically 0.02 to 8% by weight, and more specifically 0.03 to 5% by weight based on the total weight of the solid content in the light conversion ink composition, but is not limited thereto.

When the additive is included within the above range, it is preferable because the flatness and adhesion of the light conversion ink composition can be improved. If the additive is included in less than the above range, expected effects such as flatness or adhesion may not be sufficient, and if it is included in excess of the above range, the content of light emitting particles or polymerizable monomers is reduced, resulting in a decrease in luminous intensity or curing of cured film. Since there is a problem such as deterioration, use within the above range has the advantage of improving the strength of the pixel portion and the flatness or adhesion on the surface of the pixel portion.

Among the additives, the performance can be improved by introducing an additive having a metal complex as a basic structure. A central metal complex such as Ni, Zr, Al, or Ti may be used, and it may be more preferable to use an element similar to the shell of the light emitting particle as the central metal complex. In addition, it is also possible for those skilled in the art to appropriately add and use additives such as ultraviolet absorbers and anti-agglomeration agents within a range that does not impair the effects of the present invention.

<Light conversion laminated board, backlight unit and image display device>

One embodiment of the present invention is a light conversion laminated board that absorbs light emitted from a light emitting device and converts it to blue, green, or red light, and emits the light, wherein the light conversion laminated board is formed using the above-described photoconversion ink composition.

In addition, the present invention may provide a photoconversion pixel substrate manufactured using the above-described photoconversion ink composition and functioning as a color filter of RED, GREEN, and BLUE.

The photo-conversion laminated substrate and/or the photo-conversion pixel substrate may be formed by applying the above-described photo-conversion ink composition to a predetermined area using an inkjet method and curing the applied photo-conversion ink composition.

The substrate may include a substrate with a flat surface such as a glass substrate, a silicon substrate, a polycarbonate substrate, a polyester substrate, an aromatic polyamide substrate, a polyamideimide substrate, a polyimide substrate, an Al substrate, and a GaAs substrate, but is limited thereto. it is not going to be These substrates can be subjected to pretreatment such as chemical treatment with a chemical such as a silane coupling agent, plasma treatment, ion plating treatment, sputtering treatment, vapor phase reaction treatment, and vacuum deposition treatment. When a silicon substrate or the like is used as the substrate, a charge coupled device (CCD), a thin film transistor (TFT), or the like may be formed on a surface of the silicon substrate or the like. Also, a barrier rib matrix may be formed. The curing may be performed under thermal curing conditions.

For example, the curing may be performed at 100 to 250 °C, preferably 150 to 230 °C, for 5 to 30 minutes, preferably 10 minutes.

In order to be ejected from a piezo inkjet head, which is an example of an inkjet injector, to form an appropriate phase on a substrate, properties such as viscosity, fluidity, and quantum dot particles must be balanced with the inkjet head. The piezo inkjet head used in the present invention is not limited, but ejects ink having a droplet size of about 3 to 100 pL, preferably about 5 to 40 pL.

The viscosity of the light conversion ink composition of the present invention is suitably about 3 to 50 cP, more preferably adjusted in the range of 7 to 40 cP.

The light conversion laminated substrate according to the present invention can exhibit excellent light output when applied to a blue light source.

An embodiment of the present invention is a green light emitting device that emits green light, and may specifically emit green light having a wavelength of 500 to 600 nm, but is not limited thereto.

The green light emitting device may be a green light emitting diode (LED).

One embodiment of the present invention relates to a backlight unit comprising a light conversion laminated substrate applied to the blue light source.

The backlight unit may further include commonly included components such as a light guide plate and a reflector.

One embodiment of the present invention relates to an image display device including the backlight unit.

The image display device of the present invention includes not only a conventional liquid crystal display device, but also various image display devices such as an electroluminescence display device, a plasma display device, and a field emission display device.

In addition, one embodiment of the present invention relates to a photoconversion pixel including a cured product of the photoconversion ink composition described above.

For example, manufacturing a photo-conversion pixel by forming a pattern of the photo-conversion ink composition, including applying the above-described photo-conversion ink composition to a predetermined area by an inkjet method and curing the applied photo-conversion ink composition. can do.

Hereinafter, experimental examples including specific examples and comparative examples are presented to aid understanding of the present invention, but these are only illustrative of the present invention and do not limit the scope of the appended claims, and the scope and technical spirit of the present invention It is obvious to those skilled in the art that various changes and modifications to the embodiments are possible within the scope, and it is natural that these changes and modifications fall within the scope of the appended claims. In addition, "%" and "parts" indicating content below are based on weight unless otherwise specified.

Preparation Example: Synthesis of InP/ZnSe/ZnS core-shell quantum dots and preparation of dispersion

It is prepared in the order of forming an InP core, forming an InP/ZnSe core-shell, and dispersing in chloroform after forming an InP/ZnSe/ZnS core-shell.

First, 0.4 mmol (0.058 g) of indium acetate, 0.6 mmol (0.15 g) of palmitic acid, and 20 mL of 1-octadecene were put into a reactor and heated to 120° C. under vacuum. After 1 hour, the atmosphere in the reactor was changed to nitrogen. After heating to 280 ° C., a mixed solution of 0.2 mmol (58 μL) of trisphosphine (TMS ₃ P) and 1.0 mL of trioctylphosphine (TOP) was quickly injected and reacted for 0.5 minutes.

2.4 mmol (0.448 g) of zinc acetate, 4.8 mmol of oleic acid and 20 mL of trioctylamine were then charged into the reactor and heated to 120° C. under vacuum. After 1 hour, the atmosphere in the reactor was changed to nitrogen, and the temperature of the reactor was raised to 280°C. 2 mL of the previously synthesized InP core solution was added, followed by 4.8 mmol of selenium (Se/TOP) in trioctylphosphine, and the final mixture was reacted for 2 hours. Ethanol was added to the reaction solution quickly cooled to room temperature, and the precipitate obtained by centrifugation was filtered under reduced pressure and dried under reduced pressure to form an InP/ZnSe core-shell.

2.4 mmol (0.448 g) of zinc acetate, 4.8 mmol of oleic acid and 20 mL of trioctylamine were then charged into the reactor and heated to 120° C. under vacuum. After 1 hour, the atmosphere in the reactor was changed to nitrogen, and the temperature of the reactor was raised to 280°C. 2 mL of the previously synthesized InP core solution was added, followed by 4.8 mmol of sulfur (S/TOP) in trioctylphosphine, and the final mixture was reacted for 2 hours. After adding ethanol to the reaction solution rapidly cooled to room temperature, the precipitate obtained by centrifugation was filtered under reduced pressure and dried under reduced pressure to obtain quantum dots having an InP/ZnSe/ZnS core-shell structure, and then dispersed in chloroform. The solid content was adjusted to 10%. The maximum emission wavelength was 520 nm.

Examples and Comparative Examples: Preparation of light conversion ink composition

A light conversion ink composition was prepared by mixing each component according to the composition shown in Table 1 below (unit: weight %).

composition division division Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 quantum dot QD A 34.84 34.84 34.84 34.84 34.84 34.84 34.84 34.84 34.84 34.84 34.84 34.84 34.84 34.84 34.84 34.84 Scatterer TiO2 B 5.83 5.83 5.83 5.83 5.83 5.83 5.83 5.83 5.83 5.83 5.83 5.83 5.83 5.83 5.83 5.83 photopolymerization monomer HDDA C-1 51.13 43.13 49.12 43.12 45.13 45.13 47.12 47.12 47.12 50.12 42.12 47.12 52.13 41.13 43.13 47.13 A-SA C-2 3.00 3.00 1.00 7.00 3.00 3.00 3.00 3.00 3.00 0.00 8.00 3.00 3.00 3.00 3.00 Merck C-3 3.00 photopolymerization initiator I-819 D-1 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 1.00 antioxidant S-GP E-1 1.33 4.00 2.67 2.67 4.50 1.00 2.67 2.67 2.67 2.67 2.67 2.67 1.00 4.67 1.75 3.56 135A E-2 1.78 5.33 3.56 3.56 5.30 1.00 3.56 3.56 3.56 3.56 3.56 3.56 1.33 6.22 1.25 4.44 I-1035 E-3 0.89 2.67 1.78 1.78 0.20 8.00 1.78 1.78 1.78 0.67 3.11 9.00 0.00 CS-DTDTP E-4 1.78 AO-412S E-5 1.78 AO-503 E-6 1.78 additive FL-3600 E-7 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 0.20 entire 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00 100.00

A: InP / ZnSe / ZnS core-shell quantum dot dispersion prepared according to the above preparation example

B: TiO ₂ (TR-88, particle diameter 220 nm, Huntsman Co.)

C-1: 1,6-hexanediol diacrylate (HDDA, Shin Nakamura Chemical Co.)

C-2: mono-2-(acryloyloxy)ethyl succinate (A-SA, Shin Nakamura Chemical Co., Ltd.)

C-3: mono-methyl hydrogen succinate (Merck Co.)

D: Irgacure 819 (Basf Company)

E-1 : Sumilizer-GP (Sumitomo Chemical Co., Ltd.)

E-2 : ADK STAB 135A (Adeka Company)

E-3: Irganox 1035 (Basf)

E-4 : SONGNOX CS DTDTP (Songwon Industry)

E-5 : AO-412S (Adeka Company)

E-6 : AO-503 (Adeka Company)

F : FL-3600 (Basf)

Experimental Example 1. Light Conversion Efficiency Measurement Experiment

The photoconversion ink compositions of Examples and Comparative Examples prepared above were applied to a 5cm×5cm glass substrate by an inkjet method, and then irradiated with 4000mJ/cm ² using a 395nm Blue LED under nitrogen conditions, followed by 30°C in an oven at 180°C. A light conversion coating layer was prepared by heating for a minute. After placing the prepared light conversion coating layer on top of a blue light source (XLamp XR-E LED, Royal blue 450, Cree Co.), light conversion efficiency (%) was measured using a luminance meter (CAS140CT Spectrometer, Instrument Systems Co.) .

◎: 39.5% or more

○: 39.4 or more and less than 39.1%

△: 39.0 or more and less than 39.4%

X: less than 39.0%

Experimental Example 2. Light fastness measurement experiment

After leaving the prepared light conversion coating layer in a blue light source (XLamp XR-E LED, Royal blue 450, Cree) for 1 hour, the retention rate (%) for the initial light conversion efficiency was measured.

◎: retention rate of 90% or more

○: Retention rate 88 or more and less than 90%

△: Retention rate greater than 85 and 87% or less

X: Retention rate 85% or less

Experimental Example 3. Reliability Measurement Experiment

After depositing SiNx (Cluster PECVD, SUNIC Co.) on the fabricated substrate, it is put into a high-temperature, high-humidity oven (Jeotech Co., Ltd. TH-I) under 85 ° C / 85% RH conditions to perform the 8585 Test. Then, the change rate (%) of the light conversion efficiency value before input was measured.

◎ : 97~104%

○ : 94~96% / 105~107%

△: less than 92 to 94% / less than 108 to 110%

X: less than 92% / more than 110%

Experimental Example 4. Continuous jetting property measurement experiment

The prepared light conversion composition was connected to an inkjetting device (OMNIJET300, Unijet Co.), and it was evaluated whether it was continuously discharged without clogging within 2 hours.

◎ : 2hr

○: 1.5 or more and less than 2 hr

△: 1 hr or more and less than 1.5 hr

X : Less than 1hr

Experimental Example 5. Coating film uniformity measurement experiment

Film thicknesses were measured at 5 points on the fabricated substrate, and the level of deviation was confirmed.

◎: Δ1.0㎛ or less

○: More than Δ1.0 and 1.5 μm or less

△: More than Δ1.5 and 2.0 μm or less

X: Exceeding Δ2.0㎛

The experimental results are shown in Table 2 below.

evaluation
item Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 light conversion efficiency ◎ ◎ ◎ ◎ ◎ ◎ O O O △ O ◎ X △ X X reliability ◎ ◎ ◎ ◎ ◎ ◎ O O O △ △ ◎ △ X △ X continuous jetting ◎ ◎ ◎ ◎ ◎ ◎ O O O O △ ◎ △ X X X coating uniformity ◎ ◎ ◎ ◎ ◎ ◎ O O O △ △ ◎ X X X X light fastness ◎ ◎ ◎ ◎ ◎ ◎ O O O △ △ ◎ X X X X

According to the above experimental results, Examples 1 to 12 including 4 to 12% by weight of an antioxidant based on the total weight of the light conversion ink composition according to the present invention, and 0.2 to 8% by weight of a sulfur-based antioxidant among them, have light conversion efficiency. , it showed excellent effects in terms of light fastness, reliability, continuous jetting property and uniformity of the coating film.

On the other hand, it was confirmed that Comparative Examples 1 to 4 containing less than 4% by weight or more than 12% by weight of antioxidants or less than 0.2% by weight or more than 8% by weight of sulfur-based antioxidants were relatively inferior in the same evaluation items.

Through these experimental results, when an antioxidant is included in a certain weight ratio in the light conversion ink composition, and a sulfur-based antioxidant is included in a certain weight ratio, the light conversion efficiency, light resistance, reliability, continuous jetting property, and coating film uniformity are improved. It was confirmed that an excellent effect was obtained.

Claims (11)

luminescent particles; photopolymerization monomer; And a light conversion ink composition comprising an antioxidant,
The antioxidant includes a sulfur-based antioxidant,
Based on the total weight of the solid content of the light conversion ink composition, the sulfur-based antioxidant is included in 0.2 to 8% by weight, the antioxidant is characterized in that it is included in 4 to 12% by weight, the light conversion ink composition.
The method of claim 1,
Characterized in that the sulfur-based antioxidant comprises an ester group and a benzene ring of a left-right symmetric structure, the light conversion ink composition.
The method of claim 1,
The antioxidant further comprises at least one selected from phenol-based antioxidants and phosphorus-based antioxidants in addition to the sulfur-based antioxidants, the light conversion ink composition.
The method of claim 1,
The photopolymerizable monomer comprises a monomer derived from succinic acid, the light conversion ink composition.
The method of claim 4,
The photopolymerizable monomer is characterized in that it comprises 1 to 7% by weight based on the total weight of the solid content of the light conversion ink composition, the light conversion ink composition.
The method of claim 1,
A light conversion ink composition further comprising at least one of scattering particles and a photopolymerization initiator.
A light conversion laminated substrate manufactured using the light conversion ink composition according to any one of claims 1 to 6.
A photoconversion pixel substrate manufactured using the photoconversion ink composition according to any one of claims 1 to 6.
A backlight unit comprising the light conversion laminated board according to claim 7 .
An image display device comprising the photoconversion pixel substrate of claim 8.
An image display device comprising the backlight unit of claim 9.