WO2019069780A1 - Ink and light-emitting element - Google Patents

Ink and light-emitting element Download PDF

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WO2019069780A1
WO2019069780A1 PCT/JP2018/035895 JP2018035895W WO2019069780A1 WO 2019069780 A1 WO2019069780 A1 WO 2019069780A1 JP 2018035895 W JP2018035895 W JP 2018035895W WO 2019069780 A1 WO2019069780 A1 WO 2019069780A1
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group
light emitting
nanocrystals
ink
layer
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PCT/JP2018/035895
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French (fr)
Japanese (ja)
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徹 鶴田
秋山 英也
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Dic株式会社
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    • CCHEMISTRY; METALLURGY
    • C09DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
    • C09KMATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
    • C09K11/00Luminescent, e.g. electroluminescent, chemiluminescent materials
    • C09K11/06Luminescent, e.g. electroluminescent, chemiluminescent materials containing organic luminescent materials
    • HELECTRICITY
    • H05ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05BELECTRIC HEATING; ELECTRIC LIGHT SOURCES NOT OTHERWISE PROVIDED FOR; CIRCUIT ARRANGEMENTS FOR ELECTRIC LIGHT SOURCES, IN GENERAL
    • H05B33/00Electroluminescent light sources
    • H05B33/12Light sources with substantially two-dimensional radiating surfaces
    • H05B33/14Light sources with substantially two-dimensional radiating surfaces characterised by the chemical or physical composition or the arrangement of the electroluminescent material, or by the simultaneous addition of the electroluminescent material in or onto the light source
    • HELECTRICITY
    • H10SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
    • H10KORGANIC ELECTRIC SOLID-STATE DEVICES
    • H10K50/00Organic light-emitting devices
    • H10K50/10OLEDs or polymer light-emitting diodes [PLED]
    • H10K50/14Carrier transporting layers

Definitions

  • the present invention relates to an ink and a light emitting device.
  • Devices utilizing electroluminescence such as LEDs and organic EL devices, are widely used as light sources for various display devices and the like.
  • a light emitting element using quantum dots as a light emitting material has attracted attention.
  • the light emission obtained from the quantum dot has a smaller spectrum width and a wider color gamut than the organic EL element, and thus is excellent in color reproducibility.
  • the surface of the quantum dot is generally protected by a protective material (dispersant) (see, for example, Patent Document 1).
  • An object of the present invention is to provide an ink capable of forming a light emitting layer with high light emission efficiency, and a light emitting element with high light emission efficiency.
  • R 1 to R 5 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group
  • R 1 to R 3 each independently may form a ring structure with the benzene ring to which it is attached, and l, m and n each independently represent Is an integer of 0 to 5, and o is an integer of 0 to 3.
  • a light emitting device characterized in that the light emitting layer contains a semiconductor nanocrystal having a light emitting property and a charge transporting material represented by the following general formula.
  • R 1 to R 5 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group
  • R 1 to R 3 each independently may form a ring structure with the benzene ring to which it is attached, and l, m and n each independently represent Is an integer of 0 to 5, and o is an integer of 0 to 3.
  • the present invention by using a charge transport material excellent in charge transportability (in particular, electron transportability), it is possible to obtain a light emitting layer and a light emitting element with high luminous efficiency.
  • a charge transport material excellent in charge transportability in particular, electron transportability
  • FIG. 1 is a cross-sectional view showing an embodiment of a light emitting device of the present invention.
  • the ink of the present invention contains a semiconductor nanocrystal having a light-emitting property, a dispersion medium in which the semiconductor nanocrystal is dispersed, and a charge transport material having a specific structure.
  • the ink of the present invention may contain, for example, a surfactant and the like, if necessary.
  • Nanocrystals are nanosized crystals (nanocrystal particles) that absorb excitation light and emit fluorescence or phosphorescence, and, for example, transmission type electrons It is a crystalline form having a maximum particle diameter of 100 nm or less measured by a microscope or a scanning electron microscope.
  • the nanocrystals can be excited, for example, by light energy or electrical energy of a predetermined wavelength to emit fluorescence or phosphorescence.
  • the nanocrystal may be a red light emitting crystal that emits light (red light) having an emission peak in the wavelength range of 605 to 665 nm, and emits light (green light) having an emission peak in the wavelength range of 500 to 560 nm It may be a green light emitting crystal, or may be a blue light emitting crystal which emits light (blue light) having an emission peak in the wavelength range of 420 to 480 nm. Also, in one embodiment, the ink preferably contains at least one of these nanocrystals. Note that the wavelength of the emission peak of the nanocrystal can be confirmed, for example, in a fluorescence spectrum or a phosphorescence spectrum measured using an ultraviolet-visible spectrophotometer.
  • Red light emitting nanocrystals have a wavelength of 665 nm or less, 663 nm or less, 660 nm or less, 658 nm or less, 653 nm or less, 651 nm or less, 650 nm or less, 647 nm or less, 645 nm or less, 643 nm or less, 640 nm or less, 637 nm or less, It is preferable to have an emission peak in a wavelength range of 632 nm or less or 630 nm or less, and have an emission peak in a wavelength range of 628 nm or more, 625 nm or more, 623 nm or more, 620 nm or more, 615 nm or more, 610 nm or more, 607 nm or more, or 605 nm or more preferable.
  • These upper and lower limit values can be arbitrarily combined. Also in the following similar descriptions, the upper limit value and the lower limit value individually described can be
  • Green light-emitting nanocrystals have emission peaks in the wavelength range of 560 nm or less, 557 nm or less, 555 nm or less, 547 nm or less, 545 nm or less, 543 nm or less, 537 nm or less, 535 nm or less, 532 nm or less It is preferable to have an emission peak in a wavelength range of 528 nm or more, 525 nm or more, 523 nm or more, 520 nm or more, 515 nm or more, 510 nm or more, 507 nm or more, 505 nm or more, 503 nm or more, or 500 nm or more.
  • Blue light-emitting nanocrystals have emission peaks in the wavelength range of 480 nm or less, 477 nm or less, 475 nm or less, 470 nm or less, 467 nm or less, 463 nm or less, 460 nm or less, 457 nm or less, 455 nm or less It is preferable to have an emission peak in a wavelength range of 450 nm or more, 445 nm or more, 440 nm or more, 435 nm or more, 430 nm or more, 428 nm or more, 425 nm or more, 422 nm or more, or 420 nm or more.
  • the wavelength (emission color) of light emitted by the nanocrystals depends on the size (for example, particle diameter) of the nanocrystals according to the solution of the Schrodinger wave equation of the well potential model, but the energy gap of the nanocrystals is also Dependent. Therefore, the emission color of the nanocrystal can be selected (adjusted) by changing the constituent material and the size.
  • the nanocrystals may be formed of a semiconductor material and can have various structures.
  • the nanocrystal may be composed only of the core composed of the first semiconductor material, and the core composed of the first semiconductor material and at least a part of the core are covered with the first semiconductor It may be configured to have a material and a shell composed of a second semiconductor material different from the material.
  • the nanocrystal structure may be a structure consisting only of the core (core structure) or a structure consisting of the core and the shell (core / shell structure).
  • the nanocrystal covers at least a part of the shell and is a third semiconductor different from the first and second semiconductor materials. It may further have a shell (second shell) composed of a material.
  • the structure of the nanocrystals may be a structure (core / shell / shell structure) composed of the core, the first shell and the second shell.
  • each of the core and the shell may be composed of a mixed crystal (for example, CdSe + CdS, CIS + ZnS, etc.) containing two or more semiconductor materials.
  • the nanocrystal is at least one semiconductor material selected from the group consisting of II-VI semiconductors, III-V semiconductors, I-III-VI semiconductors, IV semiconductors and I-II-IV-VI semiconductors. It is preferable to be composed of
  • Specific semiconductor materials include, for example, CdS, CdSe, CdTe, ZnS, ZnTe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, CdSTe, ZnSeTe, ZnSeTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgSe, CdHgSe, CdHgTe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSeCs, CdZnSe: CdHg
  • the nanocrystals composed of these semiconductor materials can easily control the emission spectrum, can reduce the production cost and improve the mass productivity while securing the reliability.
  • red light emitting nanocrystals include nanocrystals of CdSe; rod-like nanocrystals of CdSe; rod-like nanocrystals including a shell of CdS and a core of CdSe; a shell of CdS and a core of ZnSe Rod-like nanocrystals; nanocrystals with CdS shell and CdSe core; nanocrystals with CdS shell and ZnSe core; nanocrystals with ZnS shell and InP core; ZnS shell and CdSe Nanocrystals with a core of CdSe: ZnS mixed crystal nanocrystals; CdSe ZnS mixed crystal rodlike nanocrystals; InP nanocrystals; InP rodlike nanocrystals; CdSe and CdS and Mixed crystal nanocrystals; rod-like nanocrystals of mixed crystals of CdSe and CdS; nanocrystals of mixed crystals of
  • green light emitting nanocrystals include nanocrystals of CdSe; rod-like nanocrystals of CdSe; nanocrystals including a shell of ZnS and a core of InP; nanocrystals including a shell of ZnS and a core of CdSe; Nanocrystals of mixed crystals of CdSe and ZnS; rod-like nanocrystals of mixed crystals of CdSe and ZnS, and the like can be mentioned.
  • blue light emitting nanocrystals include nanocrystals of ZnSe; rod-like nanocrystals of ZnSe; nanocrystals of ZnS; rod-like nanocrystals of ZnS; nanocrystal comprising a shell of ZnSe and a core of ZnS; A rod-like nanocrystal provided with a shell of ZnSe and a core of ZnS; a nanocrystal of CdS; a rod-like nanocrystal of CdS, and the like.
  • nanocrystals are the same chemical composition, the color which should be light-emitted from a nanocrystal can be changed into red or green by designing the average particle diameter of itself.
  • the nanocrystals themselves have minimal adverse effects on the human body and the like. Therefore, if the nanocrystals containing as little as possible cadmium, selenium, etc. are selected and used alone or if the nanocrystals containing the above elements (cadmium, selenium etc.) are used, the above elements can be reduced as much as possible. It is preferable to use in combination with the nanocrystals of
  • the shape of the nanocrystal is not particularly limited, and may be any geometric shape or any irregular shape.
  • Examples of the shape of the nanocrystal include a sphere, a tetrahedron, an ellipsoid, a pyramid, a disc, a branch, a net, and a rod.
  • a shape with less directionality for example, spherical shape, tetrahedral shape, etc.
  • the uniformity and flowability of the ink can be further enhanced by using the nanocrystals of such shape.
  • the average particle diameter (volume average diameter) of the nanocrystals is preferably 40 nm or less, more preferably 30 nm or less, and still more preferably 20 nm or less. Nanocrystals having such an average particle size are preferable because they easily emit light of a desired wavelength.
  • the average particle diameter (volume average diameter) of the nanocrystals is preferably 1 nm or more, more preferably 1.5 nm or more, and still more preferably 2 nm or more.
  • the nanocrystals having such an average particle size are preferable not only because they easily emit light of a desired wavelength, but also because they can improve the dispersibility in ink and storage stability.
  • the average particle diameter (volume average diameter) of a nanocrystal is measured by a transmission electron microscope or a scanning electron microscope, and is obtained by computing a volume average diameter.
  • nanocrystals have high reactivity because they have surface atoms that can be coordination sites. Nanocrystals are prone to aggregation due to such high reactivity and large surface area as compared to common pigments. Nanocrystals produce luminescence due to quantum size effects. Therefore, when nanocrystals aggregate, a quenching phenomenon occurs, leading to a decrease in fluorescence quantum yield, and a decrease in luminance and color reproducibility. That is, the ink formed by dispersing the nanocrystals in the dispersion medium as in the present invention is likely to cause deterioration of the light emission characteristics due to aggregation unlike the ink formed by dissolving the organic light emitting material in the solvent. For this reason, in the ink of the present invention, preparation from the viewpoint of securing dispersion stability of nanocrystals is important.
  • the dispersing agent (organic ligand) compatible with the dispersion medium is supported (held) on the surface of the nanocrystal, in other words, the surface of the nanocrystal is not damaged by the dispersing agent. It may be activated.
  • the presence of the dispersant can improve the dispersion stability of the nanocrystals in the ink.
  • the dispersant is supported on the surface of the nanocrystal by, for example, covalent bond, coordinate bond, ionic bond, hydrogen bond, van der Waals bond, or the like.
  • the term "supported” is a general term for the state in which the dispersing agent is adsorbed, attached or bonded to the surface of the nanocrystal.
  • the dispersing agent can be detached from the surface of the nanocrystal, and the support by the nanocrystal and the detachment from the nanocrystal are in an equilibrium state, and these can be repeated.
  • the dispersant is not particularly limited as long as it is a compound that can improve the dispersion stability of the nanocrystals in the ink.
  • Dispersants are classified into low molecular weight dispersants and high molecular weight dispersants.
  • low molecular weight means a molecule having a weight average molecular weight (Mw) of 5,000 or less
  • polymer means a molecule having a weight average molecular weight (Mw) of more than 5,000.
  • Weight average molecular weight (Mw)” is a value measured using gel permeation chromatography (GPC) using polystyrene as a standard substance.
  • low molecular weight dispersants include oleic acid; triethyl phosphate, TOP (trioctyl phosphine), TOPO (trioctyl phosphine oxide), hexyl phosphonic acid (HPA), tetradecyl phosphonic acid (TDPA), octyl phosphine Phosphorus atom-containing compounds such as acid (OPA); nitrogen atom-containing compounds such as oleylamine, octylamine, trioctylamine and hexadecylamine; sulfur atoms such as 1-decanethiol, octanethiol, dodecanethiol and amyl sulfide Containing compounds etc. are mentioned.
  • a polymer compound having a functional group that can be supported on the surface of nanocrystals can be used.
  • functional groups primary amino group, secondary amino group, tertiary amino group, phosphoric acid group, phosphoric acid ester group, phosphonic acid group, phosphonic acid ester group, phosphinic acid group, phosphinic acid ester group, Thiol group, thioether group, sulfonic acid group, sulfonic acid ester group, carboxylic acid group, carboxylic acid ester group, hydroxyl group, ether group, imidazolyl group, triazinyl group, pyrrolidonyl group, isocyanuric acid group, boric acid ester group, boronic acid And the like.
  • a primary amino group, a secondary amino group, a tertiary amino group, a carboxylic acid ester group from the viewpoint of easy synthesis of a polymer compound having a plurality of functional groups combined to enhance the ability to support nanocrystals.
  • a phosphoric acid group, a phosphoric acid ester group, a phosphonic acid group, a phosphonic acid ester group, and a carboxylic acid group are preferable in that the hydroxyl group and the ether group have sufficient ability to support nanocrystals even if they are singly.
  • primary amino group, secondary amino group, tertiary amino group, phosphoric acid group, phosphonic acid group, and carboxylic acid group are more preferable in that they have high ability to support nanocrystals appropriately in the ink.
  • polymer dispersant having a primary amino group examples include linear amines such as polyalkylene glycol amines, polyester amines, urethane-modified polyester amines, polyalkylene glycol diamines, polyester diamines, urethane-modified polyester diamines, A comb-type polyamine having an amino group in the side chain of the acrylic polymer) may, for example, be mentioned.
  • a polymer dispersant having a secondary amino group for example, a comb type having a main chain including a linear polyethyleneimine skeleton having a large number of secondary amino groups, and a side chain of polyester, acrylic resin, polyurethane or the like Block copolymers and the like can be mentioned.
  • polymer dispersant having a tertiary amino group examples include star-shaped amines such as tri (polyalkylene glycol) amines, and the like.
  • polymer dispersants having a primary amino group for example, JP-A 2008-037884, JP-A 2008-037949, and JP-A 2008-03818.
  • polymer dispersant having a phosphoric acid group for example, polyalkylene glycol monophosphate ester, polyalkylene glycol monoalkyl ether monophosphate ester, perfluoroalkyl polyoxyalkylene phosphate ester, perfluoroalkyl sulfonamide polyoxyalkylene phosphorus Homopolymers obtained from monomers such as acid esters, acid phosphoxyethyl mono (meth) acrylates, acid phosphoxy propyl mono (meth) acrylates, acid phosphoxy polyoxyalkylene glycol mono (meth) acrylates, or these monomers and other monomers Copolymers obtained from comonomers and (meth) acrylic polymers having a phosphoric acid group obtained by the method described in Japanese Patent No. 4697356.
  • the polymer dispersant having a phosphoric acid group can also be adjusted in pH by forming a salt by reacting an alkali metal hydroxide or an alkaline earth metal
  • polymer dispersant having a phosphonic acid group for example, polyalkylene glycol monoalkyl phosphonate, polyalkylene glycol monoalkyl ether monoalkyl phosphonate, perfluoroalkyl polyoxyalkylene alkyl phosphonate, perfluoroalkyl sulfone Amide polyoxyalkylene alkyl phosphonates, polyethylene phosphonic acid; monomers such as vinyl phosphonic acid, (meth) acryloyl oxyethyl phosphonic acid, (meth) acryloyl oxy propyl phosphonic acid, (meth) acryloyl oxy polyoxy alkylene glycol phosphonic acid And homopolymers obtained from the monomers and copolymers obtained from the monomers and other comonomers.
  • the polymer dispersant having a phosphonic acid group can also be adjusted in pH by forming a salt by reacting an alkali metal hydroxide or an alkaline earth metal hydroxide
  • polymer dispersant having a phosphinic acid group for example, polyalkylene glycol dialkyl phosphinate ester, perfluoroalkyl polyoxyalkylene dialkyl phosphinate ester, perfluoroalkyl sulfonamide polyoxyalkylene dialkyl phosphinate ester, polyethylene phosphinic acid; Homopolymers obtained from monomers such as vinylphosphinic acid, (meth) acryloyloxydialkylphosphinic acid, (meth) acryloyloxypolyoxyalkylene glycol dialkylphosphinic acids or copolymers obtained from this monomer and other comonomers .
  • the polymer dispersant having a phosphinic acid group can also be adjusted in pH by forming a salt by reacting an alkali metal hydroxide or an alkaline earth metal hydroxide.
  • polymer dispersant having a thiol group examples include polyvinyl thiol, polyalkylene glycol ethylene thiol and the like.
  • polymer dispersant having a thioether group examples include polyalkylene glycol thioethers obtained by reacting mercaptopropionic acid and glycidyl-modified polyalkylene glycol described in JP-A-2013-60637.
  • polymer dispersant having a sulfonic acid group for example, polyalkylene glycol monoalkyl sulfonic acid ester, polyalkylene glycol monoalkyl ether monoalkyl sulfonic acid ester, perfluoroalkyl polyoxyalkylene alkyl sulfonic acid ester, perfluoroalkyl sulfone Amide polyoxyalkylene alkyl sulfonic acid ester, polyethylene sulfonic acid; homopolymer obtained from monomers such as vinyl sulfonic acid, (meth) acryloyloxy alkyl sulfonic acid, (meth) acryloyloxy polyoxy alkylene glycol sulfonic acid, polystyrene sulfonic acid Or the copolymer etc.
  • the polymer dispersant having a sulfonic acid group can also be adjusted in pH by forming a salt by reacting an alkali metal hydroxide or an alkaline earth metal hydroxide.
  • polymer dispersant having a carboxylic acid group for example, polyalkylene glycol carboxylic acid, perfluoroalkyl polyoxyalkylene carboxylic acid, polyethylene carboxylic acid, polyester monocarboxylic acid, polyester dicarboxylic acid, urethane modified polyester monocarboxylic acid, urethane Homopolymers obtained from monomers such as modified polyester dicarboxylic acids; vinyl carboxylic acids, (meth) acryloyloxyalkyl carboxylic acids, (meth) acryloyloxy polyoxyalkylene glycol carboxylic acids or copolymers obtained from this monomer and other comonomers Etc.
  • the polymer dispersant having a carboxylic acid group can also be adjusted in pH by forming a salt by reacting an alkali metal hydroxide or an alkaline earth metal hydroxide.
  • the polymer dispersant having an ester group can be obtained, for example, by dehydration condensation of a monoalkyl alcohol to the polymer dispersant having a carboxylic acid group.
  • Examples of the polymer dispersant having a pyrrolidonyl group include polyvinyl pyrrolidone and the like.
  • the polymer dispersant having a specific functional group may be a synthetic product or a commercially available product.
  • a commercial item for example, DISPERBYK-102, DISPERBYK-103, DISPERBYK-108, DISPERBYK-109, DISPERBYK-110, DISPERBYK-110, DISPERBYK-111, DISPERBYK-118, DISPERBYK-118, DISPERBYK-140, DISPERBYK-140 included in the DISPERBYK series manufactured by Bick Chemie Ltd.
  • FLORENE flow Len series
  • FLOWLEN DOPA-15BHF Flowlen DOPA-33
  • Flowlen DOPA-44 include Flowlen DOPA-44, and the like.
  • One of these polymer dispersants may be used alone, or two or more thereof may be used in combination.
  • the dispersant as described above may be supported in a state in which almost the whole molecule is in contact with the nanocrystal, or may be supported in a state in which only a part of the molecule is in contact with the nanocrystal. In any state, the dispersant suitably exerts a dispersing function to disperse the nanocrystals stably in the dispersion medium.
  • the weight average molecular weight (Mw) of the dispersant is preferably 50,000 or less, and more preferably about 100 to 50,000.
  • Mw weight average molecular weight
  • the mass of the compound which is not a polymer among low molecular weight dispersing agents it replaces with a "weight average molecular weight" and uses "molecular weight.”
  • a dispersant having a weight average molecular weight equal to or more than the lower limit is excellent in the ability to support nanocrystals, and therefore, the dispersion stability of the nanocrystals in the ink can be sufficiently ensured.
  • a dispersant having a weight average molecular weight equal to or less than the above upper limit has a sufficient number of functional groups per unit weight and does not become too high in crystallinity, so that the dispersion stability of nanocrystals in the ink can be enhanced. it can.
  • the weight average molecular weight of the dispersant is not too high, the inhibition of charge transfer in the obtained light emitting layer can be prevented or suppressed.
  • the amount of the dispersant (in particular, the polymer dispersant) to the nanocrystals is preferably 50% by mass or less with respect to 100% by mass of the nanocrystals.
  • the amount of the dispersant with respect to nanocrystals is preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably 5% by mass or more with respect to 100% by mass of nanocrystals. . Thereby, sufficient dispersion stability of the nanocrystals in the ink can be maintained.
  • the charge transport material usually has a function of transporting holes and electrons injected into the light emitting layer.
  • the charge transport material represented by the following general formula is contained.
  • Such charge transport materials are particularly excellent in electron transportability. Therefore, the light emission efficiency of the obtained light emitting layer (light emitting element) can be enhanced.
  • X represents a nitrogen atom or CR 5
  • R 1 to R 5 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group
  • R 1 to R 3 each independently may form a ring structure together with the benzene ring to which it is attached
  • l, m and n each independently represent Represents an integer of 0 to 5, and o represents an integer of 0 to 3.
  • alkyl group for example, methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, cyclobutyl group, n-pentyl group And isopentyl group, neopentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, cycloheptyl group, n-octyl group, cyclooctyl group and the like.
  • alkoxy group for example, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, n-pentoxy group, isopentoxy group, neopentoxy group , N-hexoxy group, n-heptoxy group, n-octoxy group and the like.
  • Examples of the aryl group include phenyl group, naphthyl group, anthracenyl group, phenanthrenyl group, anthraquinolyl group, fluorenyl group and naphthoquinolyl group.
  • Examples of the heteroaryl group include thienyl group, pyrrolyl group, furyl group, pyridyl group, quinolyl group, isoquinolyl group, oxazolyl group, thiazolyl group, imidazolyl group, pyrazolyl group, oxadiazolyl group, triazolyl group, tetrazolyl group, pyrimidyl group, Pyridazinyl group, pyrazinyl group, triazinyl group, indolyl group, indazolyl group, carbazolyl group, phenoxazinyl group and the like can be mentioned.
  • aryloxy group a phenoxy group, a naphthoxy group, etc. are mentioned, for example.
  • heteroaryloxy group examples include a thienyloxy group, a pyrrolyloxy group, a furyloxy group, a pyridyloxy group, an isoquinolyloxy group and the like.
  • Each of R 1 to R 3 preferably independently contains at least one of an alkyl group, an aryl group and a heteroaryl group.
  • R 1 to R 3 as preferable aryl or heteroaryl groups are, for example, triarylamine, benzidine, tetraaryl-para-phenylenediamine, triarylphosphine, phenothiazine, phenoxazine, dihydrophenazine, tianthrene , Dibenzo-para-dioxin, phenoxathiin, carbazole, azulene, thiophene, pyrrole, furan, pyridine, pyrimidine, pyridazine, pyrazine, oxadiazole, quinoline, quinoxaline, anthracene, benzanthracene, pyrene, perylene, imidazole, triazine, And aryl ketones, aryl phosphine oxides, phenazines and tetraarylsilyls.
  • at least one of R 1 to R 3 preferably contains a carb
  • charge transport material examples include compounds represented by the following ET-1 to ET-5, and among them, compounds represented by the following ET-1 to ET-3 are more preferable.
  • the amount of such charge transport material contained in the ink is preferably about 0.1 to 50% by mass, more preferably about 0.5 to 40% by mass, and about 1 to 30% by mass It is further preferred that Thereby, the light emission efficiency of the obtained light emitting layer can be sufficiently enhanced.
  • the charge transport material described above not only has charge transportability, but is also excellent in the function of stably dispersing nanocrystals in the ink. Therefore, in the present invention, the dispersing agent supported on the nanocrystals may be omitted. In this case, since the dispersant which may adversely affect the light emission lifetime of the light emitting element does not exist in the light emitting layer depending on the use conditions and the like, the light emission lifetime of the light emitting element can be improved.
  • charge transport materials having a function of transporting holes and electrons may be used in combination.
  • Other charge transport materials are generally classified into polymeric charge transport materials and low molecular charge transport materials.
  • the polymer charge transport material is not particularly limited, and examples thereof include vinyl polymers such as poly (9-vinylcarbazole) (PVK); poly [N, N′-bis (4-butylphenyl) -N, N '-Bis (phenyl) -benzidine] (poly-TPA), polyfluorene (PF), poly [N, N'-bis (4-butylphenyl) -N, N'-bis (phenyl) -benzidine (Poly- TPD), poly [(9,9-dioctylfluorenyl-2,7-diyl) -co- (4,4 '-(N-(-sec-butylphenyl) diphenylamine)] (TFB), polyphenylene vinylene ( Conjugated compound polymers such as PPV), copolymers containing these monomer units, and the like can be mentioned.
  • PVK poly (9-vinylcarbazole)
  • PVK poly [N,
  • the low molecular charge transport material is not particularly limited.
  • CBP 4,4′-bis (9H-carbazol-9-yl) biphenyl
  • CBP 9,9 ′-(p-tert-butylphenyl) -3 , 3-Biscarbazole, 1,3-dicarbazolylbenzene (mCP), 4,4'-bis (9-carbazolyl) -2,2'-dimethylbiphenyl (CDBP), N, N'-dicarbazolyl-1
  • Carbazole derivatives such as 2,4-dimethylbenzene (DCB), 5,11-diphenyl-5,11-dihydroindolo [3,2-b] carbazole; bis (2-methyl-8-quinolinolate) -4- Aluminum complexes such as (phenylphenolato) aluminum (BAlq), 2,7-bis (diphenylphosphine oxide) -9,9-dimethylfluorene ( Phosphine oxide derivatives such as P06
  • surfactant for example, one or more of a fluorine-based surfactant, a silicone-based surfactant, a hydrocarbon-based surfactant and the like can be used in combination. Among these, silicone surfactants and / or hydrocarbon surfactants are preferable because they are difficult to trap charges.
  • silicone surfactant and the hydrocarbon surfactant low molecular weight or high molecular weight surfactants can be used. Specific examples thereof include, for example, BYK series manufactured by Big Chemie Co., Ltd., and Surfynol manufactured by Nisshin Chemical Industry Co., Ltd. Among these, since a coating film having high smoothness can be obtained when the ink is applied, a silicone-based surfactant made of organically modified siloxane can be suitably used.
  • Dispersion medium The nanocrystals as described above (or particles composed of nanocrystals carrying a dispersing agent) are dispersed in a dispersion medium.
  • the dispersion medium is not particularly limited, and examples thereof include aromatic hydrocarbon compounds, aromatic ester compounds, aromatic ether compounds, aromatic ketone compounds, aliphatic hydrocarbon compounds, aliphatic ester compounds, aliphatic ether compounds, and fats. Group ketone compounds, alcohol compounds, amide compounds, other compounds, etc. may be mentioned, and one or more of these may be used in combination.
  • aromatic hydrocarbon compound As an aromatic hydrocarbon compound, toluene, xylene, ethylbenzene, cumene, mesitylene, tert-butylbenzene, indane, diethylbenzene, pentylbenzene, 1,2,3,4-tetrahydronaphthalene, naphthalene, hexylbenzene, heptylbenzene, cyclohexyl Examples thereof include benzene, 1-methylnaphthalene, biphenyl, 2-ethylnaphthalene, 1-ethylnaphthalene, octylbenzene, diphenylmethane, 1,4-dimethylnaphthalene, nonylbenzene, isopropylbiphenyl, 3-ethylbiphenyl, dodecylbenzene and the like.
  • aromatic ester compound phenyl acetate, methyl benzoate, ethyl benzoate, phenyl propionate, isopropyl benzoate, methyl 4-methylbenzoate, propyl benzoate, butyl benzoate, isopentyl benzoate, ethyl p-anisate, Dimethyl phthalate etc. are mentioned.
  • aromatic ether compounds dimethoxybenzene, methoxytoluene, ethylphenyl ether, dibenzyl ether, 4-methylanisole, 2,6-dimethylanisole, ethylphenyl ether, propylphenylether, 2,5-dimethylanisole, 3, 5-dimethylanisole, 4-ethylanisole, 2,3-dimethylanisole, butylphenylether, p-dimethoxybenzene, p-propylanisole, m-dimethoxybenzene, methyl 2-methoxybenzoate, 1,3-dipropoxybenzene Diphenyl ether, 1-methoxynaphthalene, 3-phenoxytoluene, 2-ethoxynaphthalene, 1-ethoxynaphthalene and the like.
  • aromatic ketone compound examples include acetophenone, propiophenone, 4′-methylacetophenone, 4′-ethylacetophenone, butylphenyl ketone and the like.
  • aliphatic hydrocarbon compounds include pentane, hexane, octane and cyclohexane.
  • aliphatic ester compounds include ethyl acetate, butyl acetate, ethyl lactate, hexyl acetate, butyl lactate, isoamyl lactate, amyl valerate, ethyl levrilate, ⁇ -valerolactone, ethyl octanoate, ⁇ -hexalactone, isoamyl hexahydrate , Amyl hexanate, nonyl acetate, methyl decanoate, diethyl glutarate, ⁇ -heptalactone, ⁇ -caprolactone, octalactone, propylene carbonate, ⁇ -nonanolactone, hexyl hexanoate, diisopropyl adipate, ⁇ -nonanolactone, glycerol tri Acetic acid, ⁇ -decanolactone, dipropyl adipate, ⁇ -undecal
  • aliphatic ether compounds tetrahydrofuran, dioxane, propylene glycol-1-monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, propylene glycol diacetate, diethylene glycol isopropyl methyl ether, diethylene glycol diethyl ether, diethylene glycol diacetate, diethylene glycol butyl methyl ether Diethylene glycol monoethyl ether acetate, dihexyl ether, 1,3-butanediol diacetate, 1,4-butanediol diacetate, diethylene glycol monobutyl ether acetate, diethylene glycol dibutyl ether, diheptyl ether, dioctyl ether, etc. And the like.
  • aliphatic ketone compounds examples include diisobutyl ketone, cycloheptanone, isophorone, 6-undecanone and the like.
  • alcohol compounds methanol, ethanol, isopropyl alcohol, 1-heptanol, 2-ethyl-1-hexanol, propylene glycol, ethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethyl 3-hydroxyhexanate, triethylene Glycol monomethyl ether, tripropylene glycol monomethyl ether, diethylene glycol, cyclohexanol, 2-butoxyethanol and the like can be mentioned.
  • amide compound examples include N, N-dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone, N, N-dimethylacetamide and the like.
  • Other compounds include water, dimethyl sulfoxide, acetone, chloroform, methylene chloride and the like.
  • the viscosity at 25 ° C. of the dispersion medium as described above is preferably about 1 to 20 mPa ⁇ s, more preferably about 1.5 to 15 mPa ⁇ s, and about 2 to 10 mPa ⁇ s. More preferable. If the viscosity of the dispersion medium at normal temperature is within the above range, the droplets ejected from the nozzle holes of the droplet ejection head are separated into the main droplets and the small droplets when the ink is ejected by the droplet ejection method. Occurrence of the phenomenon (satellite phenomenon) can be prevented or suppressed. Therefore, it is possible to improve the landing accuracy of the droplets on the adherend.
  • dissolved gas or moisture may be generated when the ink is prepared. It is preferable to perform a post-treatment to remove as much as possible dissolved oxygen and moisture from the ink after using a dispersion medium from which as much as possible is removed or an ink is prepared. Examples of the post-treatment include degassing treatment, treatment to saturate or supersaturate an inert gas, heat treatment, dehydration treatment to be performed by passing a drying agent, and the like.
  • the dissolved oxygen and moisture in the ink are preferably 200 ppm or less, more preferably 100 ppm or less, and still more preferably 10 ppm or less.
  • the amount of nanocrystals contained in the ink is preferably about 0.01 to 20% by mass, more preferably about 0.01 to 15% by mass, and about 0.1 to 10% by mass Is more preferred.
  • the discharge stability can be further improved.
  • the particles (nanocrystals) are less likely to be aggregated with each other, and the light emission efficiency of the obtained light emitting layer can be enhanced.
  • the amount of nanocrystals contained in the ink refers to the nanocrystals, the charge transport material, and the dispersion when the ink is composed of the nanocrystals, the charge transport material, and the dispersion medium. It refers to the mass% of nanocrystals when the total amount with the medium is 100 mass%.
  • the ink of the present invention contains a charge transport material having a characteristic structure. Therefore, it is preferable to select and use a dispersion medium having high affinity to such charge transport material.
  • a dispersion medium aromatic hydrocarbon compounds such as toluene, xylene, mesitylene, tetralin, hexylbenzene, octylbenzene, nonylbenzene, dodecylbenzene, biphenyl, methyl benzoate, ethyl benzoate, propyl benzoate, Aromatic ester compounds such as butyl benzoate and dimethyl phthalate; Aromatic ether compounds such as dimethoxybenzene, methoxytoluene, ethylphenylether, dibenzylether, diphenylether, 3-phenoxytoluene; acetophenone, 4'-methylacetophenone
  • the compound is preferably at least one compound selected from the group consisting of aromatic ket
  • the light emitting device of the present invention comprises an anode and a cathode (a pair of electrodes), and a light emitting layer provided between them and comprising the dried product of the ink of the present invention, and at least one of the light emitting layer and the anode and the cathode And a charge transport layer provided therebetween.
  • the charge transport layer preferably includes at least one layer selected from the group consisting of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer.
  • the light emitting device of the present invention may further include a sealing member or the like.
  • FIG. 1 is a cross-sectional view showing an embodiment of a light emitting device of the present invention.
  • FIG. 1 for convenience, the dimensions of the respective parts and the ratio thereof are shown exaggeratingly, and may differ from the actual one.
  • the materials, dimensions, and the like described below are merely examples, and the present invention is not limited thereto, and can be appropriately changed without changing the gist of the invention.
  • the upper side of FIG. 1 will be referred to as “upper side” or “upper side” and the upper side as “lower side” or “lower side”.
  • FIG. 1 in order to avoid that a drawing becomes complicated, the description of the hatching which shows a cross section is abbreviate
  • the light emitting device 1 shown in FIG. 1 includes a hole injection layer 4, a hole transport layer 5, and a light emitting layer 6 sequentially stacked from the anode 2 side between the anode 2, the cathode 3, and the anode 2 and the cathode 3. , The electron transport layer 7 and the electron injection layer 8. Each layer will be sequentially described below.
  • the anode 2 has a function of supplying holes from the external power source toward the light emitting layer 6.
  • the constituent material (anode material) of the anode 2 is not particularly limited.
  • a metal such as gold (Au)
  • a metal halide such as copper iodide (CuI)
  • oxide examples thereof include metal oxides such as tin (SnO 2 ) and zinc oxide (ZnO). These may be used alone or in combination of two or more.
  • the thickness of the anode 2 is not particularly limited, but is preferably about 10 to 1,000 nm, and more preferably about 10 to 200 nm.
  • the anode 2 can be formed by, for example, a dry film forming method such as a vacuum evaporation method or a sputtering method.
  • the anode 2 having a predetermined pattern may be formed by a photolithography method or a method using a mask.
  • the cathode 3 has a function of supplying electrons from an external power source toward the light emitting layer 6.
  • the constituent material (cathode material) of the cathode 3 is not particularly limited, but, for example, lithium, sodium, magnesium, aluminum, silver, sodium-potassium alloy, magnesium / aluminum mixture, magnesium / silver mixture, magnesium / indium mixture, aluminum / Aluminum oxide (Al 2 O 3 ) mixture, rare earth metals, etc. may be mentioned. These may be used alone or in combination of two or more.
  • the thickness of the cathode 3 is not particularly limited, but is preferably about 0.1 to 1,000 nm, and more preferably about 1 to 200 nm.
  • the cathode 3 can be formed by, for example, a dry film forming method such as a vapor deposition method or a sputtering method.
  • the hole injection layer 4 has a function of receiving holes supplied from the anode 2 and injecting the holes into the hole transport layer 5.
  • the hole injection layer 4 may be provided as necessary, and may be omitted.
  • the constituent material (hole injection material) of the hole injection layer 4 is not particularly limited.
  • phthalocyanine compounds such as copper phthalocyanine; 4,4 ', 4' '-tris [phenyl (m-tolyl) amino] Triphenylamine derivatives such as triphenylamine; 1,4,5,8,9,12-hexaazatriphenylenehexacarbonitrile, 2,3,5,6-tetrafluoro-7,7,8,8- Cyano compounds such as tetracyano-quinodimethane; metal oxides such as vanadium oxide and molybdenum oxide; amorphous carbon; polyaniline (emeraldine), poly (3,4-ethylenedioxythiophene) -poly (styrene sulfonic acid) (PEDOT -PSS), polymers such as polypyrrole, and the like.
  • the hole injection material is preferably a polymer, and more preferably PEDOT-PSS.
  • the above-described hole injection materials may be used alone or in combination of two or more.
  • the thickness of the hole injection layer 4 is not particularly limited, but is preferably about 0.1 to 500 mm, more preferably about 1 to 300 nm, and still more preferably about 2 to 200 nm.
  • the hole injection layer 4 may have a single-layer structure or a stacked structure in which two or more layers are stacked. Such a hole injection layer 4 can be formed by a wet film formation method or a dry film formation method.
  • the hole injection layer 4 When the hole injection layer 4 is formed by a wet film formation method, an ink containing the above-described hole injection material is usually applied by various coating methods, and the obtained coating film is dried.
  • the application method is not particularly limited, and examples thereof include an inkjet method (droplet discharge method), a spin coat method, a cast method, an LB method, a letterpress printing method, a gravure printing method, a screen printing method, a nozzle printing method and the like.
  • a vacuum evaporation method, a sputtering method or the like can be suitably used.
  • the hole transport layer 5 has a function of receiving holes from the hole injection layer 4 and efficiently transporting the holes to the light emitting layer 6.
  • the hole transport layer 4 may have a function of preventing transport of electrons.
  • the hole transport layer 5 may be provided if necessary, and may be omitted.
  • the constituent material (hole transport material) of the hole transport layer 5 is not particularly limited, and, for example, TPD (N, N'-diphenyl-N, N'-di (3-methylphenyl) -1, 1 ' -Biphenyl-4,4'diamine), ⁇ -NPD (4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl), m-MTDATA (4,4 ', 4' '-) Low molecular weight triphenylamine derivatives such as tris (3-methylphenylphenylamino) triphenylamine); polyvinylcarbazole; poly [N, N'-bis (4-butylphenyl) -N, N'-bis (phenyl) -Benzidine] (poly-TPA), polyfluorene (PF), poly [N, N'-bis (4-butylphenyl) -N, N'-bis (phenyl) -benz
  • the hole transport material is preferably a triphenylamine derivative, or a polymer compound obtained by polymerizing a triphenylamine derivative having a substituent introduced therein, and the substituent having a substituent introduced therein is preferable. More preferably, it is a polymer compound obtained by polymerizing a phenylamine derivative.
  • the above-mentioned hole transport materials may be used alone or in combination of two or more.
  • the thickness of the hole transport layer 5 is not particularly limited, but is preferably about 1 to 500 nm, more preferably about 5 to 300 nm, and still more preferably about 10 to 200 nm.
  • the hole transport layer 5 may have a single-layer structure or a stacked structure in which two or more layers are stacked. Such a hole transport layer 5 can be formed by a wet film formation method or a dry film formation method.
  • the ink containing the above-mentioned hole transport material is applied by various coating methods, and the obtained coating film is dried.
  • the application method is not particularly limited, and examples thereof include an inkjet method (droplet discharge method), a spin coat method, a cast method, an LB method, a letterpress printing method, a gravure printing method, a screen printing method, a nozzle printing method and the like.
  • a vacuum evaporation method, a sputtering method or the like can be suitably used.
  • the electron injection layer 8 has a function of receiving the electrons supplied from the cathode 3 and injecting the electrons into the electron transport layer 7.
  • the electron injection layer 8 may be provided if necessary, and can be omitted.
  • the constituent material (electron injection material) of the electron injection layer 8 is not particularly limited, but, for example, alkali metal chalcogenides such as Li 2 O, LiO, Na 2 S, Na 2 Se, NaO; CaO, BaO, SrO, Alkaline earth metal chalcogenides such as BeO, BaS, MgO, CaSe; alkali metal halides such as CsF, LiF, NaF, KF, LiCl, KCl, NaCl; alkalis such as 8-hydroxyquinolinolatolithium (Liq) Metal salts; alkaline earth metal halides such as CaF 2 , BaF 2 , SrF 2 , MgF 2 , BeF 2 and the like can be mentioned.
  • alkali metal chalcogenides such as Li 2 O, LiO, Na 2 S, Na 2 Se, NaO
  • CaO, BaO, SrO, Alkaline earth metal chalcogenides such as BeO, BaS, Mg
  • alkali metal chalcogenides alkaline earth metal halides and alkali metal salts are preferable.
  • the above-mentioned electron injection materials may be used alone or in combination of two or more.
  • the thickness of the electron injection layer 8 is not particularly limited, but is preferably about 0.1 to 100 nm, more preferably about 0.2 to 50 nm, and still more preferably about 0.5 to 10 nm. preferable.
  • the electron injection layer 8 may have a single-layer structure or a stacked structure in which two or more layers are stacked. Such an electron injection layer 8 can be formed by a wet film formation method or a dry film formation method.
  • the ink containing the above-mentioned electron injection material is applied by various coating methods, and the obtained coating film is dried.
  • the application method is not particularly limited, and examples thereof include an inkjet method (droplet discharge method), a spin coat method, a cast method, an LB method, a letterpress printing method, a gravure printing method, a screen printing method, a nozzle printing method and the like.
  • an inkjet method droplet discharge method
  • a spin coat method a cast method
  • an LB method a letterpress printing method
  • a gravure printing method a screen printing method, a nozzle printing method and the like.
  • the electron transport layer 7 has a function of receiving electrons from the electron injection layer 8 and efficiently transporting it to the light emitting layer 6.
  • the electron transport layer 7 may have a function of preventing the transport of holes.
  • the electron transport layer 7 may be provided as necessary, and may be omitted.
  • the constituent material (electron transport material) of the electron transport layer 7 is not particularly limited.
  • an electron transport material it is preferable that they are an imidazole derivative, a pyridine derivative, a pyrimidine derivative, a triazine derivative, and a metal oxide (inorganic oxide).
  • the above-mentioned electron transporting materials may be used alone or in combination of two or more.
  • the thickness of the electron transport layer 7 is not particularly limited, but is preferably about 5 to 500 nm, and more preferably about 5 to 200 nm.
  • the electron transport layer 7 may be a single layer or a stack of two or more. Such an electron transport layer 7 can be formed by a wet film formation method or a dry film formation method.
  • the ink containing the above-mentioned electron transport material is applied by various coating methods, and the obtained coating film is dried.
  • the application method is not particularly limited, and examples thereof include an inkjet method (droplet discharge method), a spin coat method, a cast method, an LB method, a letterpress printing method, a gravure printing method, a screen printing method, a nozzle printing method and the like.
  • a vacuum evaporation method, a sputtering method or the like may be applied.
  • the light emitting layer 6 has a function of generating light emission using energy generated by recombination of holes and electrons injected into the light emitting layer 6.
  • the light emitting layer 6 is composed of the dried product of the ink of the present invention. Therefore, since the nanocrystals are uniformly dispersed and present in the light emitting layer 6, the light emitting layer 6 has excellent light emitting efficiency.
  • the thickness of the light emitting layer 6 is not particularly limited, but is preferably about 1 to 100 nm, and more preferably about 1 to 50 nm.
  • the light emitting layer 8 applies the ink of this invention by various coating methods, and dries the obtained coating film.
  • the coating method is not particularly limited, and examples thereof include inkjet printing (piezo method or thermal droplet discharge method), spin coating, casting, LB method, letterpress printing, gravure printing, screen printing, The nozzle printing method etc. are mentioned.
  • the nozzle printing method is a method of applying ink in the form of stripes from the nozzle holes as liquid columns.
  • the ink of the present invention can be suitably applied by inkjet printing.
  • the ink of the present invention is preferably applied by a piezo inkjet printing method.
  • a preferred apparatus used for applying the ink of the present invention is an inkjet printer having a piezo inkjet head.
  • the light emitting element 1 may further include, for example, a bank (partition wall) that divides the hole injection layer 4, the hole transport layer 5, and the light emitting layer 6.
  • the height of the bank is not particularly limited, but is preferably about 0.1 to 5 ⁇ m, more preferably about 0.2 to 4 ⁇ m, and still more preferably about 0.2 to 3 ⁇ m.
  • the width of the bank opening is preferably about 10 to 200 ⁇ m, more preferably about 30 to 200 ⁇ m, and still more preferably about 50 to 100 ⁇ m.
  • the length of the opening of the bank is preferably about 10 to 400 ⁇ m, more preferably about 20 to 200 ⁇ m, and still more preferably about 50 to 200 ⁇ m.
  • the inclination angle of the bank is preferably about 10 to 100 °, more preferably about 10 to 90 °, and still more preferably about 10 to 80 °.
  • the method of manufacturing a light emitting device is a step of forming a light emitting layer by supplying an ink as described above onto a support to form a coated film, and drying the coated film (hereinafter also referred to as "light emitting layer forming step" )have.
  • the support is the hole transport layer 5 or the electron transport layer 7 in the configuration shown in FIG. 1, but it differs depending on the light emitting element to be manufactured.
  • the support in the case of producing a light emitting device composed of an anode, a hole transport layer, a light emitting layer and a cathode, the support is a hole transport layer or a cathode.
  • the support In the case of producing a light emitting device composed of an anode, a hole injection layer, a light emitting layer, an electron injection layer and a cathode, the support is a hole injection layer or an electron injection layer.
  • the support may be an anode, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer or a cathode.
  • the support is preferably an anode, a hole injection layer or a hole transport layer, more preferably a hole injection layer or a hole transport layer, and still more preferably a hole transport layer.
  • the above-mentioned bank may be formed on the support.
  • the light emitting layer 6 can be formed only at a desired position on the support.
  • the ink of the present invention is intermittently discharged from the nozzle holes of the droplet discharge head onto the support in a predetermined pattern.
  • drawing patterning can be performed with a high degree of freedom.
  • the piezoelectric droplet discharge method the selectivity of the dispersion medium can be enhanced, and the heat load on the ink can be reduced.
  • the ejection amount of the ink is not particularly limited, but is preferably 1 to 50 pL / time, more preferably 1 to 30 pL / time, and still more preferably 1 to 20 pL / time.
  • the opening diameter of the nozzle hole is preferably about 5 to 50 ⁇ m, and more preferably about 10 to 30 ⁇ m.
  • the temperature for forming the coating film is not particularly limited, but is preferably about 10 to 50 ° C., more preferably about 15 to 40 ° C., and still more preferably about 15 to 30 ° C. By discharging droplets at such a temperature, crystallization of various components (such as nanocrystals, dispersants, charge transport materials, and the like) contained in the ink can be suppressed.
  • the relative humidity at the time of forming the coating film is not particularly limited, but is preferably about 0.01 ppm to 80%, more preferably about 0.05 ppm to 60%, and more preferably 0.1 ppm to 15 % Is more preferable, 1 ppm to 1% is particularly preferable, and 5 to 100 ppm is most preferable. It is preferable from the control of the conditions at the time of forming a coating film becoming easy for relative humidity to be more than the said lower limit. On the other hand, it is preferable from the ability to reduce the moisture content adsorbed to the coating film which may exert a bad influence on the light emitting layer 6 obtained as relative humidity is below the said upper limit.
  • the light-emitting layer 6 is obtained by drying the obtained coated film. Drying may be performed by leaving at room temperature (25 ° C.) or by heating. When drying is performed by heating, the drying temperature is not particularly limited, but is preferably about 40 to 150 ° C., and more preferably about 40 to 120 ° C.
  • drying is preferably performed under reduced pressure, and more preferably performed under reduced pressure of 0.001 to 100 Pa.
  • drying time is preferably 1 to 90 minutes, and more preferably 1 to 30 minutes.
  • the ink and light emitting element of this invention were demonstrated, this invention is not limited to the structure of embodiment mentioned above.
  • the ink and the light emitting element of the present invention may have any other optional configuration added to the configuration of the above-described embodiment, or may be replaced with any configuration that exhibits the same function. You may
  • Example 1 Preparation of Ink (Example 1) In 1.9 mL of toluene, 20 mg of the compound represented by the above ET-1 (charge transporting material) and a toluene solution (5 mg / mL, manufactured by Aldrich; product number 776785-5 ML) containing 1 mL of particles are mixed. The ink was prepared by The particles are composed of nanocrystals having a shell of ZnS and a core of InP, and oleylamine supported thereon. (Example 2) An ink was prepared in the same manner as in Example 1 except that the compound represented by ET-1 was changed to the compound represented by ET-2.
  • ET-1 charge transporting material
  • ET-2 charge transporting material
  • Example 3 An ink was prepared in the same manner as in Example 1 except that the compound represented by ET-1 was changed to the compound represented by ET-3 (manufactured by Lumtec).
  • Example 4 An ink was prepared in the same manner as in Example 1 except that the compound represented by ET-1 was changed to the compound represented by ET-4 (manufactured by Lumtec).
  • Example 5 An ink was prepared in the same manner as in Example 1 except that the compound represented by ET-1 was changed to the compound represented by ET-5.
  • UV / O 3 was irradiated to the cleaned ITO substrate, and 45 nm of poly (3,4-ethylenedioxythiophene) -poly (styrene sulfonic acid) (PEDOT-PSS) was formed by spin coating, The resultant was heated at 180 ° C. for 15 minutes to form a hole injection layer.
  • PEDOT-PSS poly(styrene sulfonic acid)
  • a 0.6 wt% xylene solution of TFB was spin-coated on the hole injection layer to form a film of 20 nm, and dried at 200 ° C. for 30 minutes in a nitrogen atmosphere to form a hole transport layer.
  • an ink containing the particles and the charge transport material was formed into a film of 30 nm by spin coating on the hole transport layer, and dried at 110 ° C. for 15 minutes in a nitrogen atmosphere to form a light emitting layer.
  • the ITO substrate formed up to the light emitting layer was transported to a vacuum deposition machine, and an electron transport layer of 40 nm, an electron injection layer of 0.5 nm, and a cathode of 100 nm were sequentially formed by vapor deposition.
  • the electron transporting layer was formed using TPBI
  • the electron injecting layer was formed using lithium fluoride
  • the cathode was formed using aluminum.
  • the ITO substrate formed up to the cathode was transported to a glove box, and the sealing glass coated with an epoxy resin was bonded to the ITO substrate. Thus, a light emitting element was manufactured.
  • the luminance when light was emitted by applying a current of 10 mA / cm 2 to the obtained light emitting element was measured with a luminance meter (Topcon BM-9, Inc.).
  • the luminance of the light emitting device obtained in Comparative Example 1 was 100%, and the luminance of the light emitting device obtained in each Example was determined as a relative value.
  • the evaluation results are shown in Table 1.
  • the light emitting device obtained in each example was excellent in luminous efficiency.
  • a light emitting element provided with a light emitting layer formed using an ink containing a charge transport material having a carbazole structure tends to improve the light emission efficiency.
  • the light emitting element obtained in Comparative Example 1 was a result of being inferior in luminous efficiency.
  • the present invention is an ink characterized by containing a semiconductor nanocrystal having a light-emitting property, a dispersion medium for dispersing the semiconductor nanocrystal, and a charge transport material represented by a specific general formula. It is possible to provide an ink capable of forming a high light emitting layer, and a light emitting element with high light emission efficiency.

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Abstract

Provided are an ink, which is capable of forming a light-emitting layer with high light-emitting efficiency, and a light-emitting element with high light-emitting efficiency. The ink according to the present invention is characterised by containing: light-emitting semiconductor nanocrystals; a dispersion medium for dispersing the semiconductor nanocrystals; and a charge transport material shown in general formula (1). Formula 1 [wherein X represents a nitrogen atom or CR5, R1-R5 independently represent a group including at least one of a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group and a heteroaryloxy group, R1-R3 may independently form a ring structure together with a benzene ring to which the same is bonded, l, m and n independently represent an integer from 0 to 5, and o represents an integer from 0 to 3.]

Description

インクおよび発光素子Ink and light emitting device
 本発明は、インクおよび発光素子に関する。 The present invention relates to an ink and a light emitting device.
 LEDや有機EL素子などの電界発光を利用した素子は、各種表示装置等の光源として広く利用されている。近年では、発光材料に量子ドットを用いた発光素子が注目されている。量子ドットから得られる発光は、有機EL素子よりスペクトル幅が小さく、色域が広がるため、色再現性に優れる。また、量子ドット(半導体ナノ結晶)の表面は、一般に、保護材料(分散剤)で保護されている(例えば、特許文献1参照)。 Devices utilizing electroluminescence, such as LEDs and organic EL devices, are widely used as light sources for various display devices and the like. In recent years, a light emitting element using quantum dots as a light emitting material has attracted attention. The light emission obtained from the quantum dot has a smaller spectrum width and a wider color gamut than the organic EL element, and thus is excellent in color reproducibility. In addition, the surface of the quantum dot (semiconductor nanocrystal) is generally protected by a protective material (dispersant) (see, for example, Patent Document 1).
 特許文献1では、保護材料として、トリフェニルアミン誘導体やカルバゾール誘導体に極性基を導入した化合物が用いられている。しかしながら、それらの骨格は、電荷輸送性(特に、電子輸送性)が低いため、発光層(発光素子)の発光効率を十分に高めることができない。 In patent document 1, the compound which introduce | transduced the polar group into the triphenylamine derivative or the carbazole derivative is used as a protective material. However, since their skeletons have low charge transportability (in particular, electron transportability), the light emission efficiency of the light emitting layer (light emitting element) can not be sufficiently improved.
特開2009-99544号公報JP, 2009-99544, A
 本発明の目的は、発光効率の高い発光層を形成し得るインク、および発光効率の高い発光素子を提供することにある。 An object of the present invention is to provide an ink capable of forming a light emitting layer with high light emission efficiency, and a light emitting element with high light emission efficiency.
 このような目的は、下記の(1)~(4)の本発明により達成される。
 (1) 発光性を有する半導体ナノ結晶と、
 該半導体ナノ結晶を分散する分散媒と、
 下記一般式で示される電荷輸送材料とを含有することを特徴とするインク。
Such an object is achieved by the present invention of the following (1) to (4).
(1) Semiconductor nanocrystals having light emitting properties,
A dispersion medium for dispersing the semiconductor nanocrystals;
An ink comprising: a charge transport material represented by the following general formula:
Figure JPOXMLDOC01-appb-C000003
[式中、Xは、窒素原子またはCRを表し、R~Rは、それぞれ独立して水素原子、アルキル基、アルコキシ基、アリール基、ヘテロアリール基、アリールオキシ基、ヘテロアリールオキシ基のうちの少なくとも1つを含む基を表し、R~Rは、それぞれ独立して、それが結合するベンゼン環とともに環構造を形成してもよく、l、mおよびnは、それぞれ独立して0~5の整数を表し、oは、0~3の整数を表す。]
Figure JPOXMLDOC01-appb-C000003
[Wherein, X represents a nitrogen atom or CR 5 , and R 1 to R 5 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group R 1 to R 3 each independently may form a ring structure with the benzene ring to which it is attached, and l, m and n each independently represent Is an integer of 0 to 5, and o is an integer of 0 to 3. ]
 (2) R~Rのうちの少なくとも1つは、カルバゾール構造を含むか、またはそれが結合するベンゼン環とともにカルバゾール構造を形成している上記(1)に記載のインク。 (2) The ink according to the above (1), wherein at least one of R 1 to R 3 contains a carbazole structure or forms a carbazole structure with a benzene ring to which it is attached.
 (3) 当該インク中に含まれる前記電荷輸送材料の量は、0.1~50質量%である上記(1)または(2)に記載のインク。 (3) The ink according to (1) or (2) above, wherein the amount of the charge transport material contained in the ink is 0.1 to 50% by mass.
 (4) 一対の電極と、
 該一対の電極間に設けられた発光層と、
 該発光層と、前記一対の電極の少なくとも一方の電極との間に設けられた電荷輸送層とを備え、
 前記発光層は、発光性を有する半導体ナノ結晶と、下記一般式で示される電荷輸送材料とを含有することを特徴とする発光素子。
(4) with a pair of electrodes,
A light emitting layer provided between the pair of electrodes;
And a charge transport layer provided between the light emitting layer and at least one of the pair of electrodes.
A light emitting device characterized in that the light emitting layer contains a semiconductor nanocrystal having a light emitting property and a charge transporting material represented by the following general formula.
Figure JPOXMLDOC01-appb-C000004
[式中、Xは、窒素原子またはCRを表し、R~Rは、それぞれ独立して水素原子、アルキル基、アルコキシ基、アリール基、ヘテロアリール基、アリールオキシ基、ヘテロアリールオキシ基のうちの少なくとも1つを含む基を表し、R~Rは、それぞれ独立して、それが結合するベンゼン環とともに環構造を形成してもよく、l、mおよびnは、それぞれ独立して0~5の整数を表し、oは、0~3の整数を表す。]
Figure JPOXMLDOC01-appb-C000004
[Wherein, X represents a nitrogen atom or CR 5 , and R 1 to R 5 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group R 1 to R 3 each independently may form a ring structure with the benzene ring to which it is attached, and l, m and n each independently represent Is an integer of 0 to 5, and o is an integer of 0 to 3. ]
 本発明によれば、電荷輸送性(特に、電子輸送性)に優れる電荷輸送材料を用いることにより、発光効率の高い発光層および発光素子が得られる。 According to the present invention, by using a charge transport material excellent in charge transportability (in particular, electron transportability), it is possible to obtain a light emitting layer and a light emitting element with high luminous efficiency.
本発明の発光素子の一実施形態を示す断面図である。FIG. 1 is a cross-sectional view showing an embodiment of a light emitting device of the present invention.
 以下、本発明のインクおよび発光素子について、添付図面に示す好適実施形態に基づいて詳細に説明する。
 <インク>
 本発明のインクは、発光性を有する半導体ナノ結晶と、この半導体ナノ結晶を分散する分散媒と、特定の構造を有する電荷輸送材料とを含有する。
 なお、本発明のインクは、必要に応じて、例えば、界面活性剤等を含有してもよい。
Hereinafter, the ink and the light emitting element of the present invention will be described in detail based on preferred embodiments shown in the accompanying drawings.
<Ink>
The ink of the present invention contains a semiconductor nanocrystal having a light-emitting property, a dispersion medium in which the semiconductor nanocrystal is dispersed, and a charge transport material having a specific structure.
The ink of the present invention may contain, for example, a surfactant and the like, if necessary.
 <<半導体ナノ結晶>>
 半導体ナノ結晶(以下、単に「ナノ結晶」と言うこともある。)は、励起光を吸収して蛍光または燐光を発光するナノサイズの結晶体(ナノ結晶粒子)であり、例えば、透過型電子顕微鏡または走査型電子顕微鏡によって測定される最大粒子径が100nm以下である結晶体である。
 ナノ結晶は、例えば、所定の波長の光エネルギーや電気エネルギーにより励起され、蛍光または燐光を発することができる。
<< Semiconductor Nanocrystals >>
Semiconductor nanocrystals (hereinafter, sometimes simply referred to as “nanocrystals”) are nanosized crystals (nanocrystal particles) that absorb excitation light and emit fluorescence or phosphorescence, and, for example, transmission type electrons It is a crystalline form having a maximum particle diameter of 100 nm or less measured by a microscope or a scanning electron microscope.
The nanocrystals can be excited, for example, by light energy or electrical energy of a predetermined wavelength to emit fluorescence or phosphorescence.
 ナノ結晶は、605~665nmの波長範囲に発光ピークを有する光(赤色光)を発する赤色発光性の結晶であってよく、500~560nmの波長範囲に発光ピークを有する光(緑色光)を発する緑色発光性の結晶であってよく、420~480nmの波長範囲に発光ピークを有する光(青色光)を発する青色発光性の結晶であってもよい。また、一実施形態において、インクは、これらのナノ結晶のうちの少なくとも1種を含むことが好ましい。
 なお、ナノ結晶の発光ピークの波長は、例えば、紫外可視分光光度計を用いて測定される蛍光スペクトルまたは燐光スペクトルにおいて確認することできる。
The nanocrystal may be a red light emitting crystal that emits light (red light) having an emission peak in the wavelength range of 605 to 665 nm, and emits light (green light) having an emission peak in the wavelength range of 500 to 560 nm It may be a green light emitting crystal, or may be a blue light emitting crystal which emits light (blue light) having an emission peak in the wavelength range of 420 to 480 nm. Also, in one embodiment, the ink preferably contains at least one of these nanocrystals.
Note that the wavelength of the emission peak of the nanocrystal can be confirmed, for example, in a fluorescence spectrum or a phosphorescence spectrum measured using an ultraviolet-visible spectrophotometer.
 赤色発光性のナノ結晶は、665nm以下、663nm以下、660nm以下、658nm以下、655nm以下、653nm以下、651nm以下、650nm以下、647nm以下、645nm以下、643nm以下、640nm以下、637nm以下、635nm以下、632nm以下または630nm以下の波長範囲に発光ピークを有することが好ましく、628nm以上、625nm以上、623nm以上、620nm以上、615nm以上、610nm以上、607nm以上または605nm以上の波長範囲に発光ピークを有することが好ましい。
 これらの上限値および下限値は、任意に組み合わせることができる。なお、以下の同様の記載においても、個別に記載した上限値および下限値は任意に組み合わせ可能である。
Red light emitting nanocrystals have a wavelength of 665 nm or less, 663 nm or less, 660 nm or less, 658 nm or less, 653 nm or less, 651 nm or less, 650 nm or less, 647 nm or less, 645 nm or less, 643 nm or less, 640 nm or less, 637 nm or less, It is preferable to have an emission peak in a wavelength range of 632 nm or less or 630 nm or less, and have an emission peak in a wavelength range of 628 nm or more, 625 nm or more, 623 nm or more, 620 nm or more, 615 nm or more, 610 nm or more, 607 nm or more, or 605 nm or more preferable.
These upper and lower limit values can be arbitrarily combined. Also in the following similar descriptions, the upper limit value and the lower limit value individually described can be arbitrarily combined.
 緑色発光性のナノ結晶は、560nm以下、557nm以下、555nm以下、550nm以下、547nm以下、545nm以下、543nm以下、540nm以下、537nm以下、535nm以下、532nm以下または530nm以下の波長範囲に発光ピークを有することが好ましく、528nm以上、525nm以上、523nm以上、520nm以上、515nm以上、510nm以上、507nm以上、505nm以上、503nm以上または500nm以上の波長範囲に発光ピークを有することが好ましい。 Green light-emitting nanocrystals have emission peaks in the wavelength range of 560 nm or less, 557 nm or less, 555 nm or less, 547 nm or less, 545 nm or less, 543 nm or less, 537 nm or less, 535 nm or less, 532 nm or less It is preferable to have an emission peak in a wavelength range of 528 nm or more, 525 nm or more, 523 nm or more, 520 nm or more, 515 nm or more, 510 nm or more, 507 nm or more, 505 nm or more, 503 nm or more, or 500 nm or more.
 青色発光性のナノ結晶は、480nm以下、477nm以下、475nm以下、470nm以下、467nm以下、465nm以下、463nm以下、460nm以下、457nm以下、455nm以下、452nm以下または450nm以下の波長範囲に発光ピークを有することが好ましく、450nm以上、445nm以上、440nm以上、435nm以上、430nm以上、428nm以上、425nm以上、422nm以上または420nm以上の波長範囲に発光ピークを有することが好ましい。 Blue light-emitting nanocrystals have emission peaks in the wavelength range of 480 nm or less, 477 nm or less, 475 nm or less, 470 nm or less, 467 nm or less, 463 nm or less, 460 nm or less, 457 nm or less, 455 nm or less It is preferable to have an emission peak in a wavelength range of 450 nm or more, 445 nm or more, 440 nm or more, 435 nm or more, 430 nm or more, 428 nm or more, 425 nm or more, 422 nm or more, or 420 nm or more.
 ナノ結晶が発する光の波長(発光色)は、井戸型ポテンシャルモデルのシュレディンガー波動方程式の解によれば、ナノ結晶のサイズ(例えば、粒子径)に依存するが、ナノ結晶が有するエネルギーギャップにも依存する。そのため、構成材料およびサイズを変更することにより、ナノ結晶の発光色を選択(調節)することができる。 The wavelength (emission color) of light emitted by the nanocrystals depends on the size (for example, particle diameter) of the nanocrystals according to the solution of the Schrodinger wave equation of the well potential model, but the energy gap of the nanocrystals is also Dependent. Therefore, the emission color of the nanocrystal can be selected (adjusted) by changing the constituent material and the size.
 ナノ結晶は、半導体材料で構成されていればよく、各種構造とすることができる。例えば、ナノ結晶は、第1の半導体材料で構成されるコアのみから構成されてもよく、第1の半導体材料で構成されるコアと、このコアの少なくとも一部を被覆し、第1の半導体材料と異なる第2の半導体材料で構成されるシェルとを有する構成でもよい。換言すれば、ナノ結晶の構造は、コアのみからなる構造(コア構造)であってよく、コアとシェルとからなる構造(コア/シェル構造)であってもよい。 The nanocrystals may be formed of a semiconductor material and can have various structures. For example, the nanocrystal may be composed only of the core composed of the first semiconductor material, and the core composed of the first semiconductor material and at least a part of the core are covered with the first semiconductor It may be configured to have a material and a shell composed of a second semiconductor material different from the material. In other words, the nanocrystal structure may be a structure consisting only of the core (core structure) or a structure consisting of the core and the shell (core / shell structure).
 また、ナノ結晶は、第2の半導体材料で構成されるシェル(第1のシェル)の他に、このシェルの少なくとも一部を被覆し、第1および第2の半導体材料と異なる第3の半導体材料で構成されるシェル(第2のシェル)をさらに有していてもよい。換言すれば、ナノ結晶の構造は、コアと第1のシェルと第2のシェルとからなる構造(コア/シェル/シェル構造)であってもよい。
 さらに、コアおよびシェルのそれぞれは、2種以上の半導体材料を含む混晶(例えば、CdSe+CdS、CIS+ZnS等)で構成されてもよい。
In addition to the shell composed of the second semiconductor material (first shell), the nanocrystal covers at least a part of the shell and is a third semiconductor different from the first and second semiconductor materials. It may further have a shell (second shell) composed of a material. In other words, the structure of the nanocrystals may be a structure (core / shell / shell structure) composed of the core, the first shell and the second shell.
Furthermore, each of the core and the shell may be composed of a mixed crystal (for example, CdSe + CdS, CIS + ZnS, etc.) containing two or more semiconductor materials.
 ナノ結晶は、II-VI族半導体、III-V族半導体、I-III-VI族半導体、IV族半導体およびI-II-IV-VI族半導体からなる群より選択される少なくとも1種の半導体材料で構成されることが好ましい。 The nanocrystal is at least one semiconductor material selected from the group consisting of II-VI semiconductors, III-V semiconductors, I-III-VI semiconductors, IV semiconductors and I-II-IV-VI semiconductors. It is preferable to be composed of
 具体的な半導体材料としては、例えば、CdS、CdSe、CdTe、ZnS、ZnSe、ZnTe、ZnO、HgS、HgSe、HgTe、CdSeS、CdSeTe、CdSTe、ZnSeS、ZnSeTe、ZnSTe、HgSeS、HgSeTe、HgSTe、CdZnS、CdZnSe、CdZnTe、CdHgS、CdHgSe、CdHgTe、HgZnS、HgZnSe、CdHgZnTe、CdZnSeS、CdZnSeTe、CdZnSTe、CdHgSeS、CdHgSeTe、CdHgSTe、HgZnSeS、HgZnSeTe、HgZnSTe、GaN、GaP、GaAs、GaSb、AlN、AlP、AlAs、AlSb、InN、InP、InAs、InSb、GaNP、GaNAs、GaNSb、GaPAs、GaPSb、AlNP、AlNAs、AlNSb、AlPAs、AlPSb、InNP、InNAs、InNSb、InPAs、InPSb、GaAlNP、GaAlNAs、GaAlNSb、GaAlPAs、GaAlPSb、GaInNP、GaInNAs、GaInNSb、GaInPAs、GaInPSb、InAlNP、InAlNAs、InAlNSb、InAlPAs、InAlPSb;SnS、SnSe、SnTe、PbS、PbSe、PbTe、SnSeS、SnSeTe、SnSTe、PbSeS、PbSeTe、PbSTe、SnPbS、SnPbSe、SnPbTe、SnPbSSe、SnPbSeTe、SnPbSTe、Si、Ge、SiC、SiGe、AgInSe、CuGaSe、CuInS、CuGaS、CuInSe、AgInS、AgGaSe、AgGaSおよびC等が挙げられる。 Specific semiconductor materials include, for example, CdS, CdSe, CdTe, ZnS, ZnTe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, CdSTe, ZnSeTe, ZnSeTe, HgSeS, HgSeTe, HgSTe, CdZnS, CdZnSe, CdZnTe, CdHgSe, CdHgSe, CdHgTe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSe, CdHgSeCs, CdZnSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdHgSe: CdH, CdHgSe: CdH: CdHsssssssssssssssssssssssssi InN, InP, InAs, InSb, GaNP, GaNAs, GaNSb, GaPA , GaPSb, AlNP, AlNAs, AlNSb, AlPAs, AlPSb, InNPs, InNAs, InNSb, InNSAs, InPAs, InPsb, InPSb, GaAlNs, GaAlNAs, GaAlNs, GaAlPAs, GaAlPSb, GaAlPSb, GaInNAs, GaInNSb, GaInAs, GaInPSb, InAlNInAlSb, , InAlPSb; SnS, SnSe, SnTe, PbS, PbSe, PbSe, SnSeS, SnSeTe, SnSTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbSe, SnPbTe, SnPbSSe, SnPbSeTe, SnPbSTe, Si, Ge, SiGe, AgInSe 2 CuGaSe 2, CuInS 2 CuGaS 2, CuInSe 2, AgInS 2 , AgGaSe 2, AgGaS 2 and C and the like.
 半導体材料は、CdS、CdSe、CdTe、ZnS、ZnSe、ZnTe、ZnO、HgS、HgSe、HgTe、InP、InAs、InSb、GaP、GaAs、GaSb、AgInS2、AgInSe2、AgInTe、AgGaS、AgGaSe、AgGaTe、CuInS、CuInSe、CuInTe、CuGaS、CuGaSe、CuGaTe、Si、C、GeおよびCuZnSnSからなる群より選択される少なくとも1種を含むことが好ましい。
 これらの半導体材料で構成されるナノ結晶は、発光スペクトルの制御が容易であり、信頼性を確保しつつ、生産コストを低減し、量産性を向上させることができる。
Semiconductor materials, CdS, CdSe, CdTe, ZnS , ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, InP, InAs, InSb, GaP, GaAs, GaSb, AgInS2, AgInSe2, AgInTe 2, AgGaS 2, AgGaSe 2, AgGaTe 2, CuInS 2, CuInSe 2, CuInTe 2, CuGaS 2, CuGaSe 2, CuGaTe 2, Si, C, preferably contains at least one selected from the group consisting of Ge and Cu 2 ZnSnS 4.
The nanocrystals composed of these semiconductor materials can easily control the emission spectrum, can reduce the production cost and improve the mass productivity while securing the reliability.
 赤色発光性のナノ結晶としては、例えば、CdSeのナノ結晶;CdSeのロッド状のナノ結晶;CdSのシェルとCdSeのコアとを備えるロッド状のナノ結晶;CdSのシェルとZnSeのコアとを備えるロッド状のナノ結晶;CdSのシェルとCdSeのコアとを備えるナノ結晶;CdSのシェルとZnSeのコアとを備えるナノ結晶;ZnSのシェルとInPのコアとを備えるナノ結晶;ZnSのシェルとCdSeのコアとを備えるナノ結晶;CdSeとZnSとの混晶のナノ結晶;CdSeとZnSとの混晶のロッド状のナノ結晶;InPのナノ結晶;InPのロッド状のナノ結晶;CdSeとCdSとの混晶のナノ結晶;CdSeとCdSとの混晶のロッド状のナノ結晶;ZnSeとCdSとの混晶のナノ結晶;ZnSeとCdSとの混晶のロッド状のナノ結晶等が挙げられる。 Examples of red light emitting nanocrystals include nanocrystals of CdSe; rod-like nanocrystals of CdSe; rod-like nanocrystals including a shell of CdS and a core of CdSe; a shell of CdS and a core of ZnSe Rod-like nanocrystals; nanocrystals with CdS shell and CdSe core; nanocrystals with CdS shell and ZnSe core; nanocrystals with ZnS shell and InP core; ZnS shell and CdSe Nanocrystals with a core of CdSe: ZnS mixed crystal nanocrystals; CdSe ZnS mixed crystal rodlike nanocrystals; InP nanocrystals; InP rodlike nanocrystals; CdSe and CdS and Mixed crystal nanocrystals; rod-like nanocrystals of mixed crystals of CdSe and CdS; nanocrystals of mixed crystals of ZnSe and CdS; ZnSe and C Rod-shaped nanocrystals, etc. mixed crystal of S and the like.
 緑色発光性のナノ結晶としては、例えば、CdSeのナノ結晶;CdSeのロッド状のナノ結晶;ZnSのシェルとInPのコアとを備えるナノ結晶;ZnSのシェルとCdSeのコアとを備えるナノ結晶;CdSeとZnSとの混晶のナノ結晶;CdSeとZnSとの混晶のロッド状のナノ結晶等が挙げられる。 Examples of green light emitting nanocrystals include nanocrystals of CdSe; rod-like nanocrystals of CdSe; nanocrystals including a shell of ZnS and a core of InP; nanocrystals including a shell of ZnS and a core of CdSe; Nanocrystals of mixed crystals of CdSe and ZnS; rod-like nanocrystals of mixed crystals of CdSe and ZnS, and the like can be mentioned.
 青色発光性のナノ結晶としては、例えば、ZnSeのナノ結晶;ZnSeのロッド状のナノ結晶;ZnSのナノ結晶;ZnSのロッド状のナノ結晶;ZnSeのシェルとZnSのコアとを備えるナノ結晶;ZnSeのシェルとZnSのコアとを備えるロッド状のナノ結晶;CdSのナノ結晶;CdSのロッド状のナノ結晶等が挙げられる。 Examples of blue light emitting nanocrystals include nanocrystals of ZnSe; rod-like nanocrystals of ZnSe; nanocrystals of ZnS; rod-like nanocrystals of ZnS; nanocrystal comprising a shell of ZnSe and a core of ZnS; A rod-like nanocrystal provided with a shell of ZnSe and a core of ZnS; a nanocrystal of CdS; a rod-like nanocrystal of CdS, and the like.
 なお、ナノ結晶は、同一の化学組成であっても、それ自体の平均粒子径を設計することにより、ナノ結晶から発光させるべき色を赤色にも緑色にも変更することができる。
 また、ナノ結晶は、それ自体として、人体等に対する悪影響が極力低いことが好ましい。したがって、カドミウム、セレン等が極力含まれないナノ結晶を選択して単独で用いるか、上記元素(カドミウム、セレン等)を含有するナノ結晶を用いる場合には、上記元素が極力少なくなるようにその他のナノ結晶と組み合わせて用いることが好ましい。
In addition, even if nanocrystals are the same chemical composition, the color which should be light-emitted from a nanocrystal can be changed into red or green by designing the average particle diameter of itself.
In addition, it is preferable that the nanocrystals themselves have minimal adverse effects on the human body and the like. Therefore, if the nanocrystals containing as little as possible cadmium, selenium, etc. are selected and used alone or if the nanocrystals containing the above elements (cadmium, selenium etc.) are used, the above elements can be reduced as much as possible. It is preferable to use in combination with the nanocrystals of
 ナノ結晶の形状は、特に限定されず、任意の幾何学的形状であってもよく任意の不規則な形状であってもよい。ナノ結晶の形状としては、例えば、球状、正四面体状、楕円体状、角錐形状、ディスク状、枝状、網状、ロッド状等が挙げられる。しかしながら、ナノ結晶の形状としては、方向性の少ない形状(例えば、球状、正四面体状等)が好ましい。かかる形状のナノ結晶を用いることにより、インクの均一性および流動性をより高めることができる。 The shape of the nanocrystal is not particularly limited, and may be any geometric shape or any irregular shape. Examples of the shape of the nanocrystal include a sphere, a tetrahedron, an ellipsoid, a pyramid, a disc, a branch, a net, and a rod. However, as the shape of the nanocrystal, a shape with less directionality (for example, spherical shape, tetrahedral shape, etc.) is preferable. The uniformity and flowability of the ink can be further enhanced by using the nanocrystals of such shape.
 ナノ結晶の平均粒子径(体積平均径)は、40nm以下であることが好ましく、30nm以下であることがより好ましく、20nm以下であることがさらに好ましい。かかる平均粒子径を有するナノ結晶は、所望の波長の光を発し易いことから好ましい。
 また、ナノ結晶の平均粒子径(体積平均径)は、1nm以上であることが好ましく、1.5nm以上であることがより好ましく、2nm以上であることがさらに好ましい。かかる平均粒子径を有するナノ結晶は、所望の波長の光を発し易いのみならず、インクへの分散性および保存安定性を向上させ得ることからも好ましい。
 なお、ナノ結晶の平均粒子径(体積平均径)は、透過型電子顕微鏡または走査型電子顕微鏡により測定し、体積平均径を算出することにより得られる。
The average particle diameter (volume average diameter) of the nanocrystals is preferably 40 nm or less, more preferably 30 nm or less, and still more preferably 20 nm or less. Nanocrystals having such an average particle size are preferable because they easily emit light of a desired wavelength.
The average particle diameter (volume average diameter) of the nanocrystals is preferably 1 nm or more, more preferably 1.5 nm or more, and still more preferably 2 nm or more. The nanocrystals having such an average particle size are preferable not only because they easily emit light of a desired wavelength, but also because they can improve the dispersibility in ink and storage stability.
In addition, the average particle diameter (volume average diameter) of a nanocrystal is measured by a transmission electron microscope or a scanning electron microscope, and is obtained by computing a volume average diameter.
 ところで、ナノ結晶は、配位サイトとなりうる表面原子を有するため、高い反応性を有している。ナノ結晶は、このような高い反応性を有することや、一般の顔料に比べ大きい表面積を有することから、凝集を起こし易い。
 ナノ結晶は、量子サイズ効果によって発光を生じる。このため、ナノ結晶は、凝集すると消光現象が生じ、蛍光量子収率の低下を招き、輝度および色再現性が低下する。すなわち、本発明のようなナノ結晶を分散媒に分散してなるインクは、有機発光材料を溶媒に溶解してなるインクと異なり、凝集による発光特性の低下を生じ易い。このため、本発明のインクでは、ナノ結晶の分散安定性を確保する観点からの調製が重要となる。
By the way, nanocrystals have high reactivity because they have surface atoms that can be coordination sites. Nanocrystals are prone to aggregation due to such high reactivity and large surface area as compared to common pigments.
Nanocrystals produce luminescence due to quantum size effects. Therefore, when nanocrystals aggregate, a quenching phenomenon occurs, leading to a decrease in fluorescence quantum yield, and a decrease in luminance and color reproducibility. That is, the ink formed by dispersing the nanocrystals in the dispersion medium as in the present invention is likely to cause deterioration of the light emission characteristics due to aggregation unlike the ink formed by dissolving the organic light emitting material in the solvent. For this reason, in the ink of the present invention, preparation from the viewpoint of securing dispersion stability of nanocrystals is important.
 このようなことから、一実施形態では、ナノ結晶の表面に分散媒と相溶性のある分散剤(有機リガンド)が担持(保持)されて、換言すれば、ナノ結晶の表面が分散剤によって不活性化されていてもよい。この分散剤の存在により、ナノ結晶のインク中での分散安定性を向上させることができる。
 なお、この場合、分散剤は、ナノ結晶の表面に、例えば、共有結合、配位結合、イオン結合、水素結合、ファンデルワールス結合等により担持されている。本明細書中において、「担持」とは、分散剤がナノ結晶の表面に吸着、付着または結合された状態を総称する用語である。また、分散剤は、ナノ結晶の表面から脱離することができ、ナノ結晶による担持とナノ結晶からの脱離とが平衡状態となり、これらを繰り返すことができる。
From such a thing, in one embodiment, the dispersing agent (organic ligand) compatible with the dispersion medium is supported (held) on the surface of the nanocrystal, in other words, the surface of the nanocrystal is not damaged by the dispersing agent. It may be activated. The presence of the dispersant can improve the dispersion stability of the nanocrystals in the ink.
In this case, the dispersant is supported on the surface of the nanocrystal by, for example, covalent bond, coordinate bond, ionic bond, hydrogen bond, van der Waals bond, or the like. In the present specification, the term "supported" is a general term for the state in which the dispersing agent is adsorbed, attached or bonded to the surface of the nanocrystal. In addition, the dispersing agent can be detached from the surface of the nanocrystal, and the support by the nanocrystal and the detachment from the nanocrystal are in an equilibrium state, and these can be repeated.
 分散剤は、ナノ結晶のインク中での分散安定性を向上させ得る化合物であれば、特に限定されない。分散剤は、低分子分散剤と高分子分散剤とに分類される。本明細書中において、「低分子」とは、重量平均分子量(Mw)が5,000以下の分子を意味し、「高分子」とは、重量平均分子量(Mw)が5,000超の分子を意味する。
 なお、本明細書中において、「重量平均分子量(Mw)」は、ポリスチレンを標準物質としたゲル浸透クロマトグラフィ(GPC)を用いて測定された値を採用するものとする。
The dispersant is not particularly limited as long as it is a compound that can improve the dispersion stability of the nanocrystals in the ink. Dispersants are classified into low molecular weight dispersants and high molecular weight dispersants. In the present specification, "low molecular weight" means a molecule having a weight average molecular weight (Mw) of 5,000 or less, and "polymer" means a molecule having a weight average molecular weight (Mw) of more than 5,000. Means
In the present specification, “weight average molecular weight (Mw)” is a value measured using gel permeation chromatography (GPC) using polystyrene as a standard substance.
 低分子分散剤としては、例えば、オレイン酸;リン酸トリエチル、TOP(トリオクチルフォスフィン)、TOPO(トリオクチルフォスフィンオキサイド)、ヘキシルホスホン酸(HPA)、テトラデシルホスホン酸(TDPA)、オクチルホスフィン酸(OPA)のようなリン原子含有化合物;オレイルアミン、オクチルアミン、トリオクチルアミン、ヘキサデシルアミンのような窒素原子含有化合物;1-デカンチオール、オクタンチオール、ドデカンチオール、アミルスルフィドのような硫黄原子含有化合物等が挙げられる。 Examples of low molecular weight dispersants include oleic acid; triethyl phosphate, TOP (trioctyl phosphine), TOPO (trioctyl phosphine oxide), hexyl phosphonic acid (HPA), tetradecyl phosphonic acid (TDPA), octyl phosphine Phosphorus atom-containing compounds such as acid (OPA); nitrogen atom-containing compounds such as oleylamine, octylamine, trioctylamine and hexadecylamine; sulfur atoms such as 1-decanethiol, octanethiol, dodecanethiol and amyl sulfide Containing compounds etc. are mentioned.
 高分子分散剤としては、例えば、ナノ結晶の表面に担持し得る官能基を有する高分子化合物を用いることができる。
 このような官能基としては、1級アミノ基、2級アミノ基、3級アミノ基、リン酸基、リン酸エステル基、ホスホン酸基、ホスホン酸エステル基、ホスフィン酸基、ホスフィン酸エステル基、チオール基、チオエーテル基、スルホン酸基、スルホン酸エステル基、カルボン酸基、カルボン酸エステル基、ヒドロキシル基、エーテル基、イミダゾリル基、トリアジニル基、ピロリドニル基、イソシアヌル酸基、ホウ酸エステル基、ボロン酸基等が挙げられる。
As the polymer dispersant, for example, a polymer compound having a functional group that can be supported on the surface of nanocrystals can be used.
As such functional groups, primary amino group, secondary amino group, tertiary amino group, phosphoric acid group, phosphoric acid ester group, phosphonic acid group, phosphonic acid ester group, phosphinic acid group, phosphinic acid ester group, Thiol group, thioether group, sulfonic acid group, sulfonic acid ester group, carboxylic acid group, carboxylic acid ester group, hydroxyl group, ether group, imidazolyl group, triazinyl group, pyrrolidonyl group, isocyanuric acid group, boric acid ester group, boronic acid And the like.
 これらの中でも、複数の官能基を組み合わせ、ナノ結晶への担持能力を高めた高分子化合物を合成し易い点から、1級アミノ基、2級アミノ基、3級アミノ基、カルボン酸エステル基、ヒドロキシル基、エーテル基が、単独であっても十分なナノ結晶への担持能力を有する点から、リン酸基、リン酸エステル基、ホスホン酸基、ホスホン酸エステル基、カルボン酸基が好ましい。
 さらに、インク中で適切にナノ結晶への高い担持能力を有する点から、1級アミノ基、2級アミノ基、3級アミノ基、リン酸基、ホスホン酸基、カルボン酸基がより好ましい。
Among these, a primary amino group, a secondary amino group, a tertiary amino group, a carboxylic acid ester group, from the viewpoint of easy synthesis of a polymer compound having a plurality of functional groups combined to enhance the ability to support nanocrystals. A phosphoric acid group, a phosphoric acid ester group, a phosphonic acid group, a phosphonic acid ester group, and a carboxylic acid group are preferable in that the hydroxyl group and the ether group have sufficient ability to support nanocrystals even if they are singly.
Furthermore, primary amino group, secondary amino group, tertiary amino group, phosphoric acid group, phosphonic acid group, and carboxylic acid group are more preferable in that they have high ability to support nanocrystals appropriately in the ink.
 1級アミノ基を有する高分子分散剤としては、例えば、ポリアルキレングリコールアミン、ポリエステルアミン、ウレタン変性ポリエステルアミン、ポリアルキレングリコールジアミン、ポリエステルジアミン、ウレタン変性ポリエステルジアミンのような直鎖型アミン、(メタ)アクリル系重合体の側鎖にアミノ基を有する櫛型ポリアミン等が挙げられる。
 2級アミノ基を有する高分子分散剤としては、例えば、多数の2級アミノ基を有する直鎖型ポリエチレンイミン骨格を含む主鎖と、ポリエステル、アクリル樹脂、ポリウレタン等の側鎖とを有する櫛型ブロックコポリマー等が挙げられる。
Examples of the polymer dispersant having a primary amino group include linear amines such as polyalkylene glycol amines, polyester amines, urethane-modified polyester amines, polyalkylene glycol diamines, polyester diamines, urethane-modified polyester diamines, A comb-type polyamine having an amino group in the side chain of the acrylic polymer) may, for example, be mentioned.
As a polymer dispersant having a secondary amino group, for example, a comb type having a main chain including a linear polyethyleneimine skeleton having a large number of secondary amino groups, and a side chain of polyester, acrylic resin, polyurethane or the like Block copolymers and the like can be mentioned.
 3級アミノ基を有する高分子分散剤としては、例えば、トリ(ポリアルキレングリコール)アミンのような星型アミン等が挙げられる。
 また、1級アミノ基、2級アミノ基および3級アミノ基を有する高分子分散剤としては、例えば、特開2008-037884号公報、特開2008-037949号公報、特開2008-03818号公報、特開2010-007124号公報に記載された直鎖型または多分岐型ポリエチレンイミンブロックとポリエチレングリコールブロックとを有する高分子化合物等が挙げられる。
Examples of the polymer dispersant having a tertiary amino group include star-shaped amines such as tri (polyalkylene glycol) amines, and the like.
Further, as polymer dispersants having a primary amino group, a secondary amino group and a tertiary amino group, for example, JP-A 2008-037884, JP-A 2008-037949, and JP-A 2008-03818. And high-molecular compounds having a linear or multi-branched polyethyleneimine block and a polyethylene glycol block described in JP-A-2010-007124, and the like.
 リン酸基を有する高分子分散剤としては、例えば、ポリアルキレングリコールモノリン酸エステル、ポリアルキレングリコールモノアルキルエーテルモノリン酸エステル、パーフルオロアルキルポリオキシアルキレンリン酸エステル、パーフルオロアルキルスルホンアミドポリオキシアルキレンリン酸エステル、アシッドホスホキシエチルモノ(メタ)アクリレート、アシッドホスホキシプロピルモノ(メタ)アクリレート、アシッドホスホキシポリオキシアルキレングリコールモノ(メタ)アクリレートのようなモノマーから得られるホモポリマーまたはこのモノマーとその他のコモノマーとから得られるコポリマー;特許4697356号公報に記載された方法で得られるリン酸基を有する(メタ)アクリル重合体等が挙げられる。
 なお、リン酸基を有する高分子分散剤は、アルカリ金属水酸化物やアルカリ土類金属水酸化物を反応させることで塩を形成させ、pHを調整することも可能である。
As a polymer dispersant having a phosphoric acid group, for example, polyalkylene glycol monophosphate ester, polyalkylene glycol monoalkyl ether monophosphate ester, perfluoroalkyl polyoxyalkylene phosphate ester, perfluoroalkyl sulfonamide polyoxyalkylene phosphorus Homopolymers obtained from monomers such as acid esters, acid phosphoxyethyl mono (meth) acrylates, acid phosphoxy propyl mono (meth) acrylates, acid phosphoxy polyoxyalkylene glycol mono (meth) acrylates, or these monomers and other monomers Copolymers obtained from comonomers and (meth) acrylic polymers having a phosphoric acid group obtained by the method described in Japanese Patent No. 4697356.
The polymer dispersant having a phosphoric acid group can also be adjusted in pH by forming a salt by reacting an alkali metal hydroxide or an alkaline earth metal hydroxide.
 ホスホン酸基を有する高分子分散剤としては、例えば、ポリアルキレングリコールモノアルキルホスホン酸エステル、ポリアルキレングリコールモノアルキルエーテルモノアルキルホスホン酸エステル、パーフルオロアルキルポリオキシアルキレンアルキルホスホン酸エステル、パーフルオロアルキルスルホンアミドポリオキシアルキレンアルキルホスホン酸エステル、ポリエチレンホスホン酸;ビニルホスホン酸、(メタ)アクリロイルオキシエチルホスホン酸、(メタ)アクリロイルオキシプロピルホスホン酸、(メタ)アクリロイルオキシポリオキシアルキレングリコールホスホン酸のようなモノマーから得られるホモポリマーまたはこのモノマーとその他のコモノマーとから得られるコポリマー等が挙げられる。
 なお、ホスホン酸基を有する高分子分散剤は、アルカリ金属水酸化物やアルカリ土類金属水酸化物を反応させることで塩を形成させ、pHを調整することも可能である。
As the polymer dispersant having a phosphonic acid group, for example, polyalkylene glycol monoalkyl phosphonate, polyalkylene glycol monoalkyl ether monoalkyl phosphonate, perfluoroalkyl polyoxyalkylene alkyl phosphonate, perfluoroalkyl sulfone Amide polyoxyalkylene alkyl phosphonates, polyethylene phosphonic acid; monomers such as vinyl phosphonic acid, (meth) acryloyl oxyethyl phosphonic acid, (meth) acryloyl oxy propyl phosphonic acid, (meth) acryloyl oxy polyoxy alkylene glycol phosphonic acid And homopolymers obtained from the monomers and copolymers obtained from the monomers and other comonomers.
The polymer dispersant having a phosphonic acid group can also be adjusted in pH by forming a salt by reacting an alkali metal hydroxide or an alkaline earth metal hydroxide.
 ホスフィン酸基を有する高分子分散剤としては、例えば、ポリアルキレングリコールジアルキルホスフィン酸エステル、パーフルオロアルキルポリオキシアルキレンジアルキルホスフィン酸エステル、パーフルオロアルキルスルホンアミドポリオキシアルキレンジアルキルホスフィン酸エステル、ポリエチレンホスフィン酸;ビニルホスフィン酸、(メタ)アクリロイルオキシジアルキルホスフィン酸、(メタ)アクリロイルオキシポリオキシアルキレングリコールジアルキルホスフィン酸のようなモノマーから得られるホモポリマーまたはこのモノマーとその他のコモノマーとから得られるコポリマー等が挙げられる。 なお、ホスフィン酸基を有する高分子分散剤は、アルカリ金属水酸化物やアルカリ土類金属水酸化物を反応させることで塩を形成させ、pHを調整することも可能である。 As a polymer dispersant having a phosphinic acid group, for example, polyalkylene glycol dialkyl phosphinate ester, perfluoroalkyl polyoxyalkylene dialkyl phosphinate ester, perfluoroalkyl sulfonamide polyoxyalkylene dialkyl phosphinate ester, polyethylene phosphinic acid; Homopolymers obtained from monomers such as vinylphosphinic acid, (meth) acryloyloxydialkylphosphinic acid, (meth) acryloyloxypolyoxyalkylene glycol dialkylphosphinic acids or copolymers obtained from this monomer and other comonomers . The polymer dispersant having a phosphinic acid group can also be adjusted in pH by forming a salt by reacting an alkali metal hydroxide or an alkaline earth metal hydroxide.
 チオール基を有する高分子分散剤としては、例えば、ポリビニルチオール、ポリアルキレングリコールエチレンチオール等が挙げられる。
 チオエーテル基を有する高分子分散剤としては、例えば、特開2013-60637号公報に記載されたメルカプトプロピオン酸とグリシジル変性ポリアルキレングリコールとを反応させて得られるポリアルキレングリコールチオエーテル等が挙げられる。
Examples of the polymer dispersant having a thiol group include polyvinyl thiol, polyalkylene glycol ethylene thiol and the like.
Examples of the polymer dispersant having a thioether group include polyalkylene glycol thioethers obtained by reacting mercaptopropionic acid and glycidyl-modified polyalkylene glycol described in JP-A-2013-60637.
 スルホン酸基を有する高分子分散剤としては、例えば、ポリアルキレングリコールモノアルキルスルホン酸エステル、ポリアルキレングリコールモノアルキルエーテルモノアルキルスルホン酸エステル、パーフルオロアルキルポリオキシアルキレンアルキルスルホン酸エステル、パーフルオロアルキルスルホンアミドポリオキシアルキレンアルキルスルホン酸エステル、ポリエチレンスルホン酸;ビニルスルホン酸、(メタ)アクリロイルオキシアルキルスルホン酸、(メタ)アクリロイルオキシポリオキシアルキレングリコールスルホン酸、ポリスチレンスルホン酸のようなモノマーから得られるホモポリマーまたはこのモノマーとその他のコモノマーとから得られるコポリマー等が挙げられる。
 なお、スルホン酸基を有する高分子分散剤は、アルカリ金属水酸化物やアルカリ土類金属水酸化物を反応させることで塩を形成させ、pHを調整することも可能である。
As a polymer dispersant having a sulfonic acid group, for example, polyalkylene glycol monoalkyl sulfonic acid ester, polyalkylene glycol monoalkyl ether monoalkyl sulfonic acid ester, perfluoroalkyl polyoxyalkylene alkyl sulfonic acid ester, perfluoroalkyl sulfone Amide polyoxyalkylene alkyl sulfonic acid ester, polyethylene sulfonic acid; homopolymer obtained from monomers such as vinyl sulfonic acid, (meth) acryloyloxy alkyl sulfonic acid, (meth) acryloyloxy polyoxy alkylene glycol sulfonic acid, polystyrene sulfonic acid Or the copolymer etc. which are obtained from this monomer and another comonomer are mentioned.
The polymer dispersant having a sulfonic acid group can also be adjusted in pH by forming a salt by reacting an alkali metal hydroxide or an alkaline earth metal hydroxide.
 カルボン酸基を有する高分子分散剤としては、例えば、ポリアルキレングリコールカルボン酸、パーフルオロアルキルポリオキシアルキレンカルボン酸、ポリエチレンカルボン酸、ポリエステルモノカルボン酸、ポリエステルジカルボン酸、ウレタン変性ポリエステルモノカルボン酸、ウレタン変性ポリエステルジカルボン酸;ビニルカルボン酸、(メタ)アクリロイルオキシアルキルカルボン酸、(メタ)アクリロイルオキシポリオキシアルキレングリコールカルボン酸のようなモノマーから得られるホモポリマーまたはこのモノマーとその他のコモノマーとから得られるコポリマー等が挙げられる。
 なお、カルボン酸基を有する高分子分散剤は、アルカリ金属水酸化物やアルカリ土類金属水酸化物を反応させることで塩を形成させ、pHを調整することも可能である。
As a polymer dispersant having a carboxylic acid group, for example, polyalkylene glycol carboxylic acid, perfluoroalkyl polyoxyalkylene carboxylic acid, polyethylene carboxylic acid, polyester monocarboxylic acid, polyester dicarboxylic acid, urethane modified polyester monocarboxylic acid, urethane Homopolymers obtained from monomers such as modified polyester dicarboxylic acids; vinyl carboxylic acids, (meth) acryloyloxyalkyl carboxylic acids, (meth) acryloyloxy polyoxyalkylene glycol carboxylic acids or copolymers obtained from this monomer and other comonomers Etc.
The polymer dispersant having a carboxylic acid group can also be adjusted in pH by forming a salt by reacting an alkali metal hydroxide or an alkaline earth metal hydroxide.
 エステル基を有する高分子分散剤は、前記カルボン酸基を有する高分子分散剤に、例えばモノアルキルアルコールを脱水縮合させることにより得ることができる。
 ピロリドニル基を有する高分子分散剤としては、例えば、ポリビニルピロリドン等が挙げられる。
The polymer dispersant having an ester group can be obtained, for example, by dehydration condensation of a monoalkyl alcohol to the polymer dispersant having a carboxylic acid group.
Examples of the polymer dispersant having a pyrrolidonyl group include polyvinyl pyrrolidone and the like.
 なお、特定の官能基を有する高分子分散剤は、合成品であっても市販品であってもよい。
 市販品としては、例えば、ビックケミー社製のDISPERBYKシリーズに含まれるDISPERBYK-102、DISPERBYK-103、DISPERBYK-108、DISPERBYK-109、DISPERBYK-110、DISPERBYK-111、DISPERBYK-118、DISPERBYK-140、DISPERBYK-145、DISPERBYK-161、DISPERBYK-164、DISPERBYK-168、DISPERBYK-168、DISPERBYK-180、DISPERBYK-182、DISPERBYK-184、DISPERBYK-185、DISPERBYK-190、DISPERBYK-191、DISPERBYK-2000、DISPERBYK-2001、DISPERBYK-2008、DISPERBYK-2009、DISPERBYK-2010、DISPERBYK-2012、DISPERBYK-2013、DISPERBYK-2022、DISPERBYK-2025、DISPERBYK-2050、DISPERBYK-2060、DISPERBYK-9070、DISPERBYK-9077;エボニック社製のTEGO Dispersシリーズに含まれるTEGO Dispers 610、TEGO Dispers 630、TEGO Dispers 650、TEGO Dispers 651、TEGO Dispers 652、TEGO Dispers 655、TEGO Dispers 660C、TEGO Dispers 662C、TEGO Dispers 670、TEGO Dispers 685、TEGO Dispers 700、TEGO Dispers 710、TEGO Dispers 715W、TEGO Dispers 740W、TEGO Dispers 750W、TEGO Dispers 752W、TEGO Dispers 755W、TEGO Dispers 760W;BASF社製のEFKAシリーズに含まれるEFKA-44、EFKA-46、EFKA-47、EFKA-48、EFKA-4010、EFKA-4050、EFKA-4055、EFKA-4020、EFKA-4015、EFKA-4060、EFKA-4300、EFKA-4330、EFKA-4400、EFKA-4406、EFKA-4510、EFKA-4800;日本ルーブリゾール社製のSOLSPERSEシリーズに含まれるSOLSPERS-3000、SOLSPERS-9000、SOLSPERS-16000、SOLSPERS-17000、SOLSPERS-18000、SOLSPERS-13940、SOLSPERS-20000、SOLSPERS-24000、SOLSPERS-32550、SOLSPERS-71000;味の素ファインテクノ社製のアジスパーシリーズに含まれるアジスパー(AJISPUR)PB-821、アジスパーPB-822、アジスパーPB-823;楠本化成製のDISPARLONシリーズに含まれるDISPARLON DA325、DISPARLON DA375、DISPARLON DA1800、DISPARLON DA7301;共栄社化学社製のフローレンシリーズに含まれるフローレン(FLORENE)DOPA-17HF、フローレンDOPA-15BHF、フローレンDOPA-33、フローレンDOPA-44等が挙げられる。
 なお、これら高分子分散剤は、1種を単独で用いてもよいし、2種以上を組み合わせて用いてもよい。
The polymer dispersant having a specific functional group may be a synthetic product or a commercially available product.
As a commercial item, for example, DISPERBYK-102, DISPERBYK-103, DISPERBYK-108, DISPERBYK-109, DISPERBYK-110, DISPERBYK-110, DISPERBYK-111, DISPERBYK-118, DISPERBYK-118, DISPERBYK-140, DISPERBYK-140 included in the DISPERBYK series manufactured by Bick Chemie Ltd. 145, DISPERBYK-161, DISPERBYK-164, DISPERBYK-168, DISPERBYK-168, DISPERBYK-180, DISPERBYK-182, DISPERBYK-184, DISPERBYK-185, DISPERBYK-190, DISPERBYK-191, DISPERBYK-191, DISPERBYK-2000, DISPERBYK-200 , DISPERBYK-2008, DISPERBYK-2009, DISPERBYK-2010, DISPERBYK-2012, DISPERBYK-2013, DISPERBYK-2022, DISPERBYK-2025, DISPERBYK-2050, DISPERBYK-2060, DISPERBYK-2070, DISPERBYK-9070, DISPERBYK-9077; TEGO disperss 610, TEGO disperss 630, TEGO disperss 650, TEGO disperss 651, TEGO disperss 652, TEGO disperss 655, TEGO disperss 660C, TEGO disperss 662 C, TEGO Dissers included in the disperss series 670, TEGO Disperss 685, TEGO Disperss 700, TEGO Disperss 710, TEGO Disperss 715 W, TEGO Disperss 740 W, TEGO Disperss 750 W, TEGO Disperss 752 W, TEGO Disperss 755 W, TEGO Disperss 760 W; EFKA included in the BASF EFKA series , EFKA-46, EFKA-47, EFKA-48, EFKA-4010, EFKA-4050, EFKA-4055, EFKA-4020, EFKA-4015, EFKA-4060, EFKA-4300, EFKA-4330, EFKA-4400, EFKA -4406, EFKA-4510, EFKA-4800; Japan Lubrizol -3000, SOLSPERS-9000, SOLSPERS-9000, SOLSPERS-16000, SOLSPERS-17000, SOLSPERS-18000, SOLSPERS-13940, SOLSPERS-20000, SOLSPERS-24000, SOLSPERS-24000, SOLSPERS-32550, SOLSPERS-71000 included in the SOLSPERSE series manufactured by Ajinomoto Fine Techno Co. Co., Ltd. included AZIPUR PB-821, AZIPAR PB-822, AZIPER PB-823; DISPARLON DA 325, DISPARLON DA 375, DISPARLON DA 1800, DISPARLON DA 7301 included in DISPARLON series manufactured by Kushimoto Chemical Co., Ltd .; Kyoeisha Chemical Co., Ltd. Flowlen included in manufacturing the flow Len series (FLORENE) DOPA-17HF, FLOWLEN DOPA-15BHF, Flowlen DOPA-33, include Flowlen DOPA-44, and the like.
One of these polymer dispersants may be used alone, or two or more thereof may be used in combination.
 以上のような分散剤は、その分子のほぼ全体がナノ結晶に接触した状態で担持されていてもよいし、その分子の一部のみがナノ結晶に接触した状態で担持されていてもよい。いずれの状態であっても、分散剤は、ナノ結晶を安定的に分散媒に分散させる分散機能を好適に発揮する。
 かかる観点から、分散剤の重量平均分子量(Mw)は、50,000以下であることが好ましく、100~50,000程度であることがより好ましい。なお、低分子分散剤のうち重合体でない化合物の質量を表す場合には、「重量平均分子量」に代えて「分子量」を用いる。
The dispersant as described above may be supported in a state in which almost the whole molecule is in contact with the nanocrystal, or may be supported in a state in which only a part of the molecule is in contact with the nanocrystal. In any state, the dispersant suitably exerts a dispersing function to disperse the nanocrystals stably in the dispersion medium.
From this point of view, the weight average molecular weight (Mw) of the dispersant is preferably 50,000 or less, and more preferably about 100 to 50,000. In addition, when expressing the mass of the compound which is not a polymer among low molecular weight dispersing agents, it replaces with a "weight average molecular weight" and uses "molecular weight."
 前記下限値以上の重量平均分子量を有する分散剤は、ナノ結晶に対する担持能力に優れるため、インク中におけるナノ結晶の分散安定性を十分に確保することができる。一方、前記上限値以下の重量平均分子量を有する分散剤は、その単位重量あたりの官能基数が十分であり、結晶性が高くなり過ぎないため、インク中におけるナノ結晶の分散安定性を高めることができる。また、分散剤の重量平均分子量が高か過ぎないため、得られる発光層において電荷移動が阻害されることも防止または抑制することができる。 A dispersant having a weight average molecular weight equal to or more than the lower limit is excellent in the ability to support nanocrystals, and therefore, the dispersion stability of the nanocrystals in the ink can be sufficiently ensured. On the other hand, a dispersant having a weight average molecular weight equal to or less than the above upper limit has a sufficient number of functional groups per unit weight and does not become too high in crystallinity, so that the dispersion stability of nanocrystals in the ink can be enhanced. it can. In addition, since the weight average molecular weight of the dispersant is not too high, the inhibition of charge transfer in the obtained light emitting layer can be prevented or suppressed.
 分散剤を用いる場合、ナノ結晶に対する分散剤(特に、高分子分散剤)の量は、ナノ結晶100質量%に対して50質量%以下であることが好ましい。これにより、ナノ結晶に分散剤を担持させる際に、ナノ結晶の表面に不要な有機物が残留または析出し難い。このため、分散剤による層が電荷の移動を阻害する絶縁層となり難く、発光特性の悪化を防止することができる。
 一方、ナノ結晶に対する分散剤の量は、ナノ結晶100質量%に対して1質量%以上であることが好ましく、3質量%以上であることがより好ましく、5質量%以上であることがさらに好ましい。これにより、インク中におけるナノ結晶の十分な分散安定性を保持することができる。
When a dispersant is used, the amount of the dispersant (in particular, the polymer dispersant) to the nanocrystals is preferably 50% by mass or less with respect to 100% by mass of the nanocrystals. Thereby, when carrying a dispersing agent to a nanocrystal, unnecessary organic substance remains or precipitates hardly on the surface of a nanocrystal. Therefore, the layer made of the dispersant does not easily form an insulating layer which inhibits the movement of charge, and the deterioration of the light emission characteristics can be prevented.
On the other hand, the amount of the dispersant with respect to nanocrystals is preferably 1% by mass or more, more preferably 3% by mass or more, and still more preferably 5% by mass or more with respect to 100% by mass of nanocrystals. . Thereby, sufficient dispersion stability of the nanocrystals in the ink can be maintained.
 <<電荷輸送材料>>
 電荷輸送材料は、通常、発光層に注入された正孔および電子を輸送する機能を有する。本発明では、下記一般式で示される電荷輸送材料を含有する。かかる電荷輸送材料は、特に電子輸送性に優れる。このため、得られる発光層(発光素子)の発光効率を高めることができる。
<< Charge Transport Material >>
The charge transport material usually has a function of transporting holes and electrons injected into the light emitting layer. In the present invention, the charge transport material represented by the following general formula is contained. Such charge transport materials are particularly excellent in electron transportability. Therefore, the light emission efficiency of the obtained light emitting layer (light emitting element) can be enhanced.
Figure JPOXMLDOC01-appb-C000005
Figure JPOXMLDOC01-appb-C000005
 式中、Xは、窒素原子またはCRを表し、R~Rは、それぞれ独立して水素原子、アルキル基、アルコキシ基、アリール基、ヘテロアリール基、アリールオキシ基、ヘテロアリールオキシ基のうちの少なくとも1つを含む基を表し、R~Rは、それぞれ独立して、それが結合するベンゼン環とともに環構造を形成してもよく、l、mおよびnは、それぞれ独立して0~5の整数を表し、oは、0~3の整数を表す。 In the formula, X represents a nitrogen atom or CR 5 , and R 1 to R 5 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, or a heteroaryloxy group R 1 to R 3 each independently may form a ring structure together with the benzene ring to which it is attached, and l, m and n each independently represent Represents an integer of 0 to 5, and o represents an integer of 0 to 3.
 アルキル基としては、例えば、メチル基、エチル基、n-プロピル基、イソプロピル基、シクロプロピル基、n-ブチル基、イソブチル基、sec-ブチル基、tert-ブチル基、シクロブチル基、n-ペンチル基、イソペンチル基、ネオペンチル基、シクロペンチル基、n-へキシル基、シクロヘキシル基、n-ヘプチル基、シクロヘプチル基、n-オクチル基、シクロオクチル基等が挙げられる。
 アルコキシ基としては、例えば、メトキシ基、エトキシ基、n-プロポキシ基、イソプロポキシ基、n-ブトキシ基、イソブトキシ基、sec-ブトキシ基、tert-ブトキシ基、n-ペントキシ基、イソペントキシ基、ネオペントキシ基、n-へキソキシ基、n-ヘプトキシ基、n-オクトキシ基、等が挙げられる。
As the alkyl group, for example, methyl group, ethyl group, n-propyl group, isopropyl group, cyclopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, cyclobutyl group, n-pentyl group And isopentyl group, neopentyl group, cyclopentyl group, n-hexyl group, cyclohexyl group, n-heptyl group, cycloheptyl group, n-octyl group, cyclooctyl group and the like.
As the alkoxy group, for example, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, n-butoxy group, isobutoxy group, sec-butoxy group, tert-butoxy group, n-pentoxy group, isopentoxy group, neopentoxy group , N-hexoxy group, n-heptoxy group, n-octoxy group and the like.
 アリール基としては、例えば、フェニル基、ナフチル基、アントラセニル基、フェナンスレニル基、アントラキノリル基、フルオレニル基、ナフトキノリル基等が挙げられる。
 ヘテロアリール基としては、例えば、チエニル基、ピロリル基、フリル基、ピリジル基、キノリル基、イソキノリル基、オキサゾリル基、チアゾリル基、イミダゾリル基、ピラゾリル基、オキサジアゾリル基、トリアゾリル基、テトラゾリル基、ピリミジル基、ピリダジニル基、ピラジニル基、トリアジニル基、インドリル基、インダゾリル基、カルバゾリル基、フェノキサジニル基等が挙げられる。
Examples of the aryl group include phenyl group, naphthyl group, anthracenyl group, phenanthrenyl group, anthraquinolyl group, fluorenyl group and naphthoquinolyl group.
Examples of the heteroaryl group include thienyl group, pyrrolyl group, furyl group, pyridyl group, quinolyl group, isoquinolyl group, oxazolyl group, thiazolyl group, imidazolyl group, pyrazolyl group, oxadiazolyl group, triazolyl group, tetrazolyl group, pyrimidyl group, Pyridazinyl group, pyrazinyl group, triazinyl group, indolyl group, indazolyl group, carbazolyl group, phenoxazinyl group and the like can be mentioned.
 アリールオキシ基としては、例えば、フェノキシ基、ナフトキシ基等が挙げられる。
 ヘテロアリールオキシ基としては、例えば、チエニルオキシ基、ピロリルオキシ基、フリルオキシ基、ピリジルオキシ基、イソキノリルオキシ基等が挙げられる。
As an aryloxy group, a phenoxy group, a naphthoxy group, etc. are mentioned, for example.
Examples of the heteroaryloxy group include a thienyloxy group, a pyrrolyloxy group, a furyloxy group, a pyridyloxy group, an isoquinolyloxy group and the like.
 R~Rは、それぞれ独立して、アルキル基、アリール基、ヘテロアリール基のうちの少なくとも1つを含むことが好ましい。 Each of R 1 to R 3 preferably independently contains at least one of an alkyl group, an aryl group and a heteroaryl group.
 R~Rの好ましいアリール基またはヘテロアリール基としての具体的な構造は、例えば、トリアリールアミン、ベンジジン、テトラアリール-パラ-フェニレンジアミン、トリアリールホスフィン、フェノチアジン、フェノキサジン、ジヒドロフェナジン、チアントレン、ジベンゾ-パラ-ジオキシン、フェノキサチイン、カルバゾール、アズレン、チオフェン、ピロール、フラン、ピリジン、ピリミジン、ピリダジン、ピラジン、オキサジアゾール、キノリン、キノキサリン、アントラセン、ベンズアントラセン、ピレン、ペリレン、イミダゾール、トリアジン、アリールケトン、アリールホスフィンオキシド、フェナジン、テトラアリールシリルが挙げられる。
 特に、R~Rのうちの少なくとも1つは、カルバゾール構造を含むか、またはそれが結合するベンゼン環とともにカルバゾール構造を形成していることが好ましい。カルバゾール構造を含む電荷輸送材料は、特に電荷輸送性に優れている。
Specific structures of R 1 to R 3 as preferable aryl or heteroaryl groups are, for example, triarylamine, benzidine, tetraaryl-para-phenylenediamine, triarylphosphine, phenothiazine, phenoxazine, dihydrophenazine, tianthrene , Dibenzo-para-dioxin, phenoxathiin, carbazole, azulene, thiophene, pyrrole, furan, pyridine, pyrimidine, pyridazine, pyrazine, oxadiazole, quinoline, quinoxaline, anthracene, benzanthracene, pyrene, perylene, imidazole, triazine, And aryl ketones, aryl phosphine oxides, phenazines and tetraarylsilyls.
In particular, at least one of R 1 to R 3 preferably contains a carbazole structure or forms a carbazole structure with the benzene ring to which it is attached. The charge transport material containing a carbazole structure is particularly excellent in charge transportability.
 電荷輸送材料の具体例としては、例えば、下記ET-1~ET-5で示される化合物等が挙げられ、中でも、下記ET-1~ET-3で示される化合物がより好ましい。 Specific examples of the charge transport material include compounds represented by the following ET-1 to ET-5, and among them, compounds represented by the following ET-1 to ET-3 are more preferable.
Figure JPOXMLDOC01-appb-C000006
Figure JPOXMLDOC01-appb-C000006
Figure JPOXMLDOC01-appb-C000007
Figure JPOXMLDOC01-appb-C000007
Figure JPOXMLDOC01-appb-C000008
Figure JPOXMLDOC01-appb-C000008
Figure JPOXMLDOC01-appb-C000009
Figure JPOXMLDOC01-appb-C000009
Figure JPOXMLDOC01-appb-C000010
Figure JPOXMLDOC01-appb-C000010
 このような電荷輸送材料のインク中に含まれる量は、0.1~50質量%程度であることが好ましく、0.5~40質量%程度であることがより好ましく、1~30質量%程度であることがさらに好ましい。これにより、得られる発光層の発光効率を十分に高めることができる。 The amount of such charge transport material contained in the ink is preferably about 0.1 to 50% by mass, more preferably about 0.5 to 40% by mass, and about 1 to 30% by mass It is further preferred that Thereby, the light emission efficiency of the obtained light emitting layer can be sufficiently enhanced.
 なお、以上説明した電荷輸送材料は、電荷輸送性を有するのみならず、ナノ結晶をインク中で安定的に分散させる機能にも優れている。したがって、本発明では、ナノ結晶に担持させる分散剤を省略してもよい。この場合、使用条件等によっては、発光素子の発光寿命に悪影響を及ぼす可能性のある分散剤が発光層中に存在しなくなるので、発光素子の発光寿命を向上させることができる。 The charge transport material described above not only has charge transportability, but is also excellent in the function of stably dispersing nanocrystals in the ink. Therefore, in the present invention, the dispersing agent supported on the nanocrystals may be omitted. In this case, since the dispersant which may adversely affect the light emission lifetime of the light emitting element does not exist in the light emitting layer depending on the use conditions and the like, the light emission lifetime of the light emitting element can be improved.
 また、正孔および電子を輸送する機能を有する他の電荷輸送材料を組み合わせて用いるようにしてもよい。他の電荷輸送材料は、一般に、高分子電荷輸送材料と低分子電荷輸送材料とに分類される。 Further, other charge transport materials having a function of transporting holes and electrons may be used in combination. Other charge transport materials are generally classified into polymeric charge transport materials and low molecular charge transport materials.
 高分子電荷輸送材料としては、特に限定されないが、例えば、ポリ(9-ビニルカルバゾール)(PVK)のようなビニル重合体;ポリ[N,N’-ビス(4-ブチルフェニル)-N,N’-ビス(フェニル)-ベンジジン](poly-TPA)、ポリフルオレン(PF)、ポリ[N,N’-ビス(4-ブチルフェニル)-N,N’-ビス(フェニル)-ベンジジン(Poly-TPD)、ポリ[(9,9-ジオクチルフルオレニル-2,7-ジイル)-コ-(4,4’-(N-(-sec-ブチルフェニル)ジフェニルアミン)](TFB)、ポリフェニレンビニレン(PPV)のような共役系化合物重合体、これらのモノマー単位を含む共重合体等が挙げられる。 The polymer charge transport material is not particularly limited, and examples thereof include vinyl polymers such as poly (9-vinylcarbazole) (PVK); poly [N, N′-bis (4-butylphenyl) -N, N '-Bis (phenyl) -benzidine] (poly-TPA), polyfluorene (PF), poly [N, N'-bis (4-butylphenyl) -N, N'-bis (phenyl) -benzidine (Poly- TPD), poly [(9,9-dioctylfluorenyl-2,7-diyl) -co- (4,4 '-(N-(-sec-butylphenyl) diphenylamine)] (TFB), polyphenylene vinylene ( Conjugated compound polymers such as PPV), copolymers containing these monomer units, and the like can be mentioned.
 低分子電荷輸送材料としては、特に限定されないが、例えば、4,4’-ビス(9H-カルバゾール-9-イル)ビフェニル(CBP)、9,9’-(p-tert-ブチルフェニル)-3,3-ビスカルバゾール、1,3-ジカルバゾリルベンゼン(mCP)、4,4’-ビス(9-カルバゾリル)-2,2’-ジメチルビフェニル(CDBP)、N,N’-ジカルバゾリル-1,4-ジメチルベンゼン(DCB)、5,11-ジフェニル-5,11-ジハイドロインドロ[3,2-b]カルバゾールのようなカルバゾール誘導体;ビス(2-メチル-8-キノリノレート)-4-(フェニルフェノラト)アルミニウム(BAlq)のようなアルミニウム錯体、2,7-ビス(ジフェニルホスフィンオキシド)-9,9-ジメチルフルオレン(P06)のようなホスフィンオキシド誘導体;3,5-ビス(9-カルバゾリル)テトラフェニルシラン(SimCP)、1,3-ビス(トリフェニルシリル)ベンゼン(UGH3)のようなシラン誘導体;4,4’-ビス[N-(1-ナフチル)-N-フェニルアミノ]ビフェニル(α―NPD)のようなトリフェニルアミン誘導体、9-(4,6-ジフェニル-1,3,5-トリアジン-2-イル)-9H-カルバゾール、9-(2,6-ジフェニルピリミジン-4-イル)-9H-カルバゾールのような複素環誘導体、これらの化合物の誘導体等が挙げられる。 The low molecular charge transport material is not particularly limited. For example, 4,4′-bis (9H-carbazol-9-yl) biphenyl (CBP), 9,9 ′-(p-tert-butylphenyl) -3 , 3-Biscarbazole, 1,3-dicarbazolylbenzene (mCP), 4,4'-bis (9-carbazolyl) -2,2'-dimethylbiphenyl (CDBP), N, N'-dicarbazolyl-1 Carbazole derivatives such as 2,4-dimethylbenzene (DCB), 5,11-diphenyl-5,11-dihydroindolo [3,2-b] carbazole; bis (2-methyl-8-quinolinolate) -4- Aluminum complexes such as (phenylphenolato) aluminum (BAlq), 2,7-bis (diphenylphosphine oxide) -9,9-dimethylfluorene ( Phosphine oxide derivatives such as P06); Silane derivatives such as 3,5-bis (9-carbazolyl) tetraphenylsilane (SimCP), 1,3-bis (triphenylsilyl) benzene (UGH3); 4,4 ' -Phenyl [N- (1-naphthyl) -N-phenylamino] biphenyl (α-NPD) such as triphenylamine derivatives, 9- (4,6-diphenyl-1,3,5-triazin-2-yl Heterocyclic derivatives such as 9H-carbazole, 9- (2,6-diphenylpyrimidin-4-yl) -9H-carbazole, derivatives of these compounds, and the like.
 <<界面活性剤>>
 界面活性剤としては、例えば、フッ素系界面活性剤、シリコーン系界面活性剤、炭化水素系界面活性剤等のうちの1種または2種以上を組み合わせて用いることができる。これらの中でも、電荷をトラップし難いことから、シリコーン系界面活性剤および/または炭化水素系界面活性剤が好ましい。
<< Surfactant >>
As the surfactant, for example, one or more of a fluorine-based surfactant, a silicone-based surfactant, a hydrocarbon-based surfactant and the like can be used in combination. Among these, silicone surfactants and / or hydrocarbon surfactants are preferable because they are difficult to trap charges.
 シリコーン系界面活性剤および炭化水素系界面活性剤としては、低分子型または高分子型の界面活性剤を用いることができる。
 これらの具体例としては、例えば、ビックケミー社製のBYKシリーズ、日信化学工業株式会社製のサーフィノール等が挙げられる。これらの中でも、インクを塗布した際に平滑性の高い塗膜が得られることから、有機変性シロキサンからなるシリコーン系界面活性剤を好適に用いることができる。
As the silicone surfactant and the hydrocarbon surfactant, low molecular weight or high molecular weight surfactants can be used.
Specific examples thereof include, for example, BYK series manufactured by Big Chemie Co., Ltd., and Surfynol manufactured by Nisshin Chemical Industry Co., Ltd. Among these, since a coating film having high smoothness can be obtained when the ink is applied, a silicone-based surfactant made of organically modified siloxane can be suitably used.
 <<分散媒>>
 前述したようなナノ結晶(または分散剤を担持したナノ結晶からなる粒子)が分散媒に分散されている。
 分散媒としては、特に限定されないが、例えば、芳香族炭化水素化合物、芳香族エステル化合物、芳香族エーテル化合物、芳香族ケトン化合物、脂肪族炭化水素化合物、脂肪族エステル化合物、脂肪族エーテル化合物、脂肪族ケトン化合物、アルコール化合物、アミド化合物、他の化合物等が挙げられ、これらのうちの1種または2種以上を組み合わせて用いることができる。
<< Dispersion medium >>
The nanocrystals as described above (or particles composed of nanocrystals carrying a dispersing agent) are dispersed in a dispersion medium.
The dispersion medium is not particularly limited, and examples thereof include aromatic hydrocarbon compounds, aromatic ester compounds, aromatic ether compounds, aromatic ketone compounds, aliphatic hydrocarbon compounds, aliphatic ester compounds, aliphatic ether compounds, and fats. Group ketone compounds, alcohol compounds, amide compounds, other compounds, etc. may be mentioned, and one or more of these may be used in combination.
 芳香族炭化水素化合物としては、トルエン、キシレン、エチルベンゼン、クメン、メシチレン、tert-ブチルベンゼン、インダン、ジエチルベンゼン、ペンチルベンゼン、1、2、3、4-テトラヒドロナフタレン、ナフタレン、ヘキシルベンゼン、ヘプチルベンゼン、シクロヘキシルベンゼン、1-メチルナフタレン、ビフェニル、2-エチルナフタレン、1-エチルナフタレン、オクチルベンゼン、ジフェニルメタン、1,4-ジメチルナフタレン、ノニルベンゼン、イソプロピルビフェニル、3-エチルビフェニル、ドデシルベンゼン等が挙げられる。 As an aromatic hydrocarbon compound, toluene, xylene, ethylbenzene, cumene, mesitylene, tert-butylbenzene, indane, diethylbenzene, pentylbenzene, 1,2,3,4-tetrahydronaphthalene, naphthalene, hexylbenzene, heptylbenzene, cyclohexyl Examples thereof include benzene, 1-methylnaphthalene, biphenyl, 2-ethylnaphthalene, 1-ethylnaphthalene, octylbenzene, diphenylmethane, 1,4-dimethylnaphthalene, nonylbenzene, isopropylbiphenyl, 3-ethylbiphenyl, dodecylbenzene and the like.
 芳香族エステル化合物としては、酢酸フェニル、安息香酸メチル、安息香酸エチル、プロピオン酸フェニル、安息香酸イソプロピル、4-メチル安息香酸メチル、安息香酸プロピル、安息香酸ブチル、安息香酸イソペンチル、エチル p-アニセート、フタル酸ジメチル等が挙げられる。 As an aromatic ester compound, phenyl acetate, methyl benzoate, ethyl benzoate, phenyl propionate, isopropyl benzoate, methyl 4-methylbenzoate, propyl benzoate, butyl benzoate, isopentyl benzoate, ethyl p-anisate, Dimethyl phthalate etc. are mentioned.
 芳香族エーテル化合物としては、ジメトキシベンゼン、メトキシトルエン、エチルフェニルエーテル、ジベンジルエーテル、4-メチルアニソール、2,6-ジメチルアニソール、エチルフェニルエーテル、プロピルフェニルエーテル、2,5-ジメチルアニソール、3,5-ジメチルアニソール、4-エチルアニソール、2,3-ジメチルアニソール、ブチルフェニルエーテル、p-ジメトキシベンゼン、p-プロピルアニソール、m-ジメトキシベンゼン、2-メトキシ安息香酸メチル、1,3-ジプロポキシベンゼン、ジフェニルエーテル、1-メトキシナフタレン、3-フェノキシトルエン、2-エトキシナフタレン、1-エトキシナフタレン等が挙げられる。 As the aromatic ether compounds, dimethoxybenzene, methoxytoluene, ethylphenyl ether, dibenzyl ether, 4-methylanisole, 2,6-dimethylanisole, ethylphenyl ether, propylphenylether, 2,5-dimethylanisole, 3, 5-dimethylanisole, 4-ethylanisole, 2,3-dimethylanisole, butylphenylether, p-dimethoxybenzene, p-propylanisole, m-dimethoxybenzene, methyl 2-methoxybenzoate, 1,3-dipropoxybenzene Diphenyl ether, 1-methoxynaphthalene, 3-phenoxytoluene, 2-ethoxynaphthalene, 1-ethoxynaphthalene and the like.
 芳香族ケトン化合物としては、アセトフェノン、プロピオフェノン、4’-メチルアセトフェノン、4’-エチルアセトフェノン、ブチルフェニルケトン等が挙げられる。
 脂肪族炭化水素化合物としては、ペンタン、ヘキサン、オクタン、シクロヘキサン等が挙げられる。
Examples of the aromatic ketone compound include acetophenone, propiophenone, 4′-methylacetophenone, 4′-ethylacetophenone, butylphenyl ketone and the like.
Examples of aliphatic hydrocarbon compounds include pentane, hexane, octane and cyclohexane.
 脂肪族エステル化合物としては、酢酸エチル、酢酸ブチル、乳酸エチル、酢酸ヘキシル、乳酸ブチル、乳酸イソアミル、アミルバレラート、エチルレブリレート、γ-バレロラクトン、オクタン酸エチル、γ-ヘキサラクトン、イソアミルヘキサネート、アミルヘキサネート、酢酸ノニル、デカン酸メチル、グルタル酸ジエチル、γ-ヘプタラクトン、ε-カプロラクトン、オクタラクトン、炭酸プロピレン、γ-ノナノラクトン、ヘキサン酸ヘキシル、アジピン酸ジイソプロピル、δ-ノナノラクトン、グリセロール三酢酸、δ-デカノラクトン、アジピン酸ジプロピル、δ-ウンデカラクトン等が挙げられる。 Examples of aliphatic ester compounds include ethyl acetate, butyl acetate, ethyl lactate, hexyl acetate, butyl lactate, isoamyl lactate, amyl valerate, ethyl levrilate, γ-valerolactone, ethyl octanoate, γ-hexalactone, isoamyl hexahydrate , Amyl hexanate, nonyl acetate, methyl decanoate, diethyl glutarate, γ-heptalactone, ε-caprolactone, octalactone, propylene carbonate, γ-nonanolactone, hexyl hexanoate, diisopropyl adipate, δ-nonanolactone, glycerol tri Acetic acid, δ-decanolactone, dipropyl adipate, δ-undecalactone and the like can be mentioned.
 脂肪族エーテル化合物としては、テトラヒドロフラン、ジオキサン、プロピレングリコール-1-モノメチルエーテルアセテート、ジエチレングリコールジメチルエーテル、ジエチレングリコールエチルメチルエーテル、プロピレングリコールジアセテート、ジエチレングリコールイソプロピルメチルエーテル、ジエチレングリコールジエチルエーテル、ジエチレングリコールジアセテート、ジエチレングリコールブチルメチルエーテル、ジエチレングリコールモノエチルエーテルアセテート、ジヘキシルエーテル、1,3-ブタンジオールジアセテート、1,4-ブタンジオールジアセテート、ジエチレングリコールモノブチルエーテルアセテート、ジエチレングリコールジブチルエーテル、ジヘプチルエーテル、ジオクチルエーテル等が挙げられる。 As aliphatic ether compounds, tetrahydrofuran, dioxane, propylene glycol-1-monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol ethyl methyl ether, propylene glycol diacetate, diethylene glycol isopropyl methyl ether, diethylene glycol diethyl ether, diethylene glycol diacetate, diethylene glycol butyl methyl ether Diethylene glycol monoethyl ether acetate, dihexyl ether, 1,3-butanediol diacetate, 1,4-butanediol diacetate, diethylene glycol monobutyl ether acetate, diethylene glycol dibutyl ether, diheptyl ether, dioctyl ether, etc. And the like.
 脂肪族ケトン化合物としては、ジイソブチルケトン、シクロヘプタノン、イソホロン、6-ウンデカノン等が挙げられる。
 アルコール化合物としては、メタノール、エタノール、イソプロピルアルコール、1-ヘプタノール、2-エチル-1-ヘキサノール、プロピレングリコ-ル、エチレングリコール、ジエチレングリコールモノエチルエーテル、ジエチレングリコールモノブチルエーテル、エチル 3-ヒドロキシヘキサネート、トリエチレングリコールモノメチルエーテル、トリプロピレングリコールモノメチルエーテル、ジエチレングリコール、シクロヘキサノール、2-ブトキシエタノール等が挙げられる。
Examples of aliphatic ketone compounds include diisobutyl ketone, cycloheptanone, isophorone, 6-undecanone and the like.
As alcohol compounds, methanol, ethanol, isopropyl alcohol, 1-heptanol, 2-ethyl-1-hexanol, propylene glycol, ethylene glycol, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, ethyl 3-hydroxyhexanate, triethylene Glycol monomethyl ether, tripropylene glycol monomethyl ether, diethylene glycol, cyclohexanol, 2-butoxyethanol and the like can be mentioned.
 アミド化合物としてはN,N-ジメチルアセトアミド、2-ピロリドン、N-メチルピロリドン、N,N-ジメチルアセトアミド等が挙げられる。
 他の化合物としては、水、ジメチルスルホキシド、アセトン、クロロホルム、塩化メチレン等が挙げられる。
Examples of the amide compound include N, N-dimethylacetamide, 2-pyrrolidone, N-methylpyrrolidone, N, N-dimethylacetamide and the like.
Other compounds include water, dimethyl sulfoxide, acetone, chloroform, methylene chloride and the like.
 以上のような分散媒の25℃における粘度は、1~20mPa・s程度であることが好ましく、1.5~15mPa・s程度であることがより好ましく、2~10mPa・s程度であることがさらに好ましい。分散媒の常温下における粘度が前記範囲であれば、インクを液滴吐出法により吐出する場合には、液滴吐出ヘッドのノズル孔から吐出された液滴が主滴と小液滴とに分離される現象(サテライト現象)の発生を防止または抑制することができる。このため、液滴の被着体に対する着弾精度を向上させることができる。 The viscosity at 25 ° C. of the dispersion medium as described above is preferably about 1 to 20 mPa · s, more preferably about 1.5 to 15 mPa · s, and about 2 to 10 mPa · s. More preferable. If the viscosity of the dispersion medium at normal temperature is within the above range, the droplets ejected from the nozzle holes of the droplet ejection head are separated into the main droplets and the small droplets when the ink is ejected by the droplet ejection method. Occurrence of the phenomenon (satellite phenomenon) can be prevented or suppressed. Therefore, it is possible to improve the landing accuracy of the droplets on the adherend.
 本発明のインクにおいて、ナノ結晶(またはナノ結晶を含む粒子)が酸素や水等により失活して、安定的に機能しない可能性がある場合、当該インクを調製する際に、溶存気体や水分を出来るだけ除去した分散媒を用いたり、インクを調製した後に、インク中から溶存酸素や水分を出来るだけ除去する後処理を行うことが好ましい。この後処理としては、例えば、脱気処理、不活性ガスを飽和または過飽和させる処理、加熱処理、乾燥剤を通過させて行う脱水処理等が挙げられる。
 なお、インク中の溶存酸素や水分は、200ppm以下にすることが好ましく、100ppm以下にすることがより好ましく、10ppm以下にすることがさらに好ましい。
In the ink of the present invention, when there is a possibility that the nanocrystals (or particles containing the nanocrystals) are inactivated by oxygen, water, etc. and do not function stably, dissolved gas or moisture may be generated when the ink is prepared. It is preferable to perform a post-treatment to remove as much as possible dissolved oxygen and moisture from the ink after using a dispersion medium from which as much as possible is removed or an ink is prepared. Examples of the post-treatment include degassing treatment, treatment to saturate or supersaturate an inert gas, heat treatment, dehydration treatment to be performed by passing a drying agent, and the like.
The dissolved oxygen and moisture in the ink are preferably 200 ppm or less, more preferably 100 ppm or less, and still more preferably 10 ppm or less.
 インク中に含まれるナノ結晶の量は、0.01~20質量%程度であることが好ましく、0.01~15質量%程度であることがより好ましく、0.1~10質量%程度であることがさらに好ましい。インク中に含まれるナノ結晶の量を前記範囲に設定することにより、インクを液滴吐出法により吐出する場合には、その吐出安定性をより向上させることができる。また、粒子(ナノ結晶)同士が凝集し難くなり、得られる発光層の発光効率を高めることもできる。 The amount of nanocrystals contained in the ink is preferably about 0.01 to 20% by mass, more preferably about 0.01 to 15% by mass, and about 0.1 to 10% by mass Is more preferred. By setting the amount of nanocrystals contained in the ink within the above range, when the ink is discharged by the droplet discharge method, the discharge stability can be further improved. In addition, the particles (nanocrystals) are less likely to be aggregated with each other, and the light emission efficiency of the obtained light emitting layer can be enhanced.
 なお、本明細書中において、「インク中に含まれるナノ結晶の量」とは、インクがナノ結晶と、電荷輸送材料と、分散媒とから構成される場合、ナノ結晶と電荷輸送材料と分散媒との合計を100質量%としたときの、ナノ結晶の質量%を指す。 In the present specification, “the amount of nanocrystals contained in the ink” refers to the nanocrystals, the charge transport material, and the dispersion when the ink is composed of the nanocrystals, the charge transport material, and the dispersion medium. It refers to the mass% of nanocrystals when the total amount with the medium is 100 mass%.
 前述したように、本発明のインクは、特徴のある構造を有する電荷輸送材料を含有する。このため、かかる電荷輸送材料と親和性の高い分散媒を選択して使用することが好ましい。
 このような分散媒としては、トルエン、キシレン、メシチレン、テトラリン、ヘキシルベンゼン、オクチルベンゼン、ノニルベンゼン、ドデシルベンゼン、ビフェニルのような芳香族炭化水素化合物、安息香酸メチル、安息香酸エチル、安息香酸プロピル、安息香酸ブチル、フタル酸ジメチルのような芳香族エステル化合物;ジメトキシベンゼン、メトキシトルエン、エチルフェニルエーテル、ジベンジルエーテル、ジフェニルエーテル、3-フェノキシトルエンのような芳香族エーテル化合物;アセトフェノン、4’-メチルアセトフェノン、4’-エチルアセトフェノン、ブチルフェニルケトンのような芳香族ケトン化合物からなる群より選択される少なくとも1種の化合物であることが好ましい。これらの分散媒を用いることにより、均一かつ均質な発光層を形成することができる。
As mentioned above, the ink of the present invention contains a charge transport material having a characteristic structure. Therefore, it is preferable to select and use a dispersion medium having high affinity to such charge transport material.
As such a dispersion medium, aromatic hydrocarbon compounds such as toluene, xylene, mesitylene, tetralin, hexylbenzene, octylbenzene, nonylbenzene, dodecylbenzene, biphenyl, methyl benzoate, ethyl benzoate, propyl benzoate, Aromatic ester compounds such as butyl benzoate and dimethyl phthalate; Aromatic ether compounds such as dimethoxybenzene, methoxytoluene, ethylphenylether, dibenzylether, diphenylether, 3-phenoxytoluene; acetophenone, 4'-methylacetophenone The compound is preferably at least one compound selected from the group consisting of aromatic ketone compounds such as 4′-ethylacetophenone and butylphenyl ketone. By using these dispersion media, a uniform and homogeneous light emitting layer can be formed.
 <発光素子>
 本発明の発光素子は、陽極および陰極(一対の電極)と、これらの間に設けられ、本発明のインクの乾燥物で構成された発光層と、発光層と陽極および陰極の少なくとも一方の電極との間に設けられた電荷輸送層とを備えている。
 なお、電荷輸送層は、正孔注入層、正孔輸送層、電子輸送層および電子注入層からなる群より選択される少なくとも1層を含むことが好ましい。また、本発明の発光素子は、さらに、封止部材等を備えてもよい。
<Light emitting element>
The light emitting device of the present invention comprises an anode and a cathode (a pair of electrodes), and a light emitting layer provided between them and comprising the dried product of the ink of the present invention, and at least one of the light emitting layer and the anode and the cathode And a charge transport layer provided therebetween.
The charge transport layer preferably includes at least one layer selected from the group consisting of a hole injection layer, a hole transport layer, an electron transport layer, and an electron injection layer. The light emitting device of the present invention may further include a sealing member or the like.
 図1は、本発明の発光素子の一実施形態を示す断面図である。
 なお、図1では、便宜上、各部の寸法およびそれらの比率を誇張して示し、実際とは異なる場合がある。また、以下に示す材料、寸法等は一例であって、本発明は、それらに限定されず、その要旨を変更しない範囲で適宜変更することが可能である。
 以下では、説明の都合上、図1の上側を「上側」または「上方」と、上側を「下側」または「下方」と言う。また、図1では、図面が煩雑になることを避けるため、断面を示すハッチングの記載を省略している。
FIG. 1 is a cross-sectional view showing an embodiment of a light emitting device of the present invention.
In FIG. 1, for convenience, the dimensions of the respective parts and the ratio thereof are shown exaggeratingly, and may differ from the actual one. In addition, the materials, dimensions, and the like described below are merely examples, and the present invention is not limited thereto, and can be appropriately changed without changing the gist of the invention.
Hereinafter, for convenience of explanation, the upper side of FIG. 1 will be referred to as “upper side” or “upper side” and the upper side as “lower side” or “lower side”. Moreover, in FIG. 1, in order to avoid that a drawing becomes complicated, the description of the hatching which shows a cross section is abbreviate | omitted.
 図1に示す発光素子1は、陽極2と、陰極3と、陽極2と陰極3との間に、陽極2側から順次積層された正孔注入層4、正孔輸送層5、発光層6、電子輸送層7および電子注入層8とを有している。
 以下、各層について順次説明する。
The light emitting device 1 shown in FIG. 1 includes a hole injection layer 4, a hole transport layer 5, and a light emitting layer 6 sequentially stacked from the anode 2 side between the anode 2, the cathode 3, and the anode 2 and the cathode 3. , The electron transport layer 7 and the electron injection layer 8.
Each layer will be sequentially described below.
 [陽極2]
 陽極2は、外部電源から発光層6に向かって正孔を供給する機能を有する。
 陽極2の構成材料(陽極材料)としては、特に限定されないが、例えば、金(Au)のような金属、ヨウ化銅(CuI)のようなハロゲン化金属、インジウムスズ酸化物(ITO)、酸化スズ(SnO)、酸化亜鉛(ZnO)のような金属酸化物等が挙げられる。これらは、単独で用いても、2種以上を組み合わせて用いてもよい。
[Anode 2]
The anode 2 has a function of supplying holes from the external power source toward the light emitting layer 6.
The constituent material (anode material) of the anode 2 is not particularly limited. For example, a metal such as gold (Au), a metal halide such as copper iodide (CuI), indium tin oxide (ITO), oxide Examples thereof include metal oxides such as tin (SnO 2 ) and zinc oxide (ZnO). These may be used alone or in combination of two or more.
 陽極2の厚さは、特に制限されないが、10~1,000nm程度であることが好ましく、10~200nm程度であることがより好ましい。
 陽極2は、例えば、真空蒸着法やスパッタリング法のような乾式成膜法により形成することができる。この際、フォトリソグラフィー法やマスクを用いた方法により、所定のパターンを有する陽極2を形成してもよい。
The thickness of the anode 2 is not particularly limited, but is preferably about 10 to 1,000 nm, and more preferably about 10 to 200 nm.
The anode 2 can be formed by, for example, a dry film forming method such as a vacuum evaporation method or a sputtering method. At this time, the anode 2 having a predetermined pattern may be formed by a photolithography method or a method using a mask.
 [陰極3]
 陰極3は、外部電源から発光層6に向かって電子を供給する機能を有する。
 陰極3の構成材料(陰極材料)としては、特に限定されないが、例えば、リチウム、ナトリウム、マグネシウム、アルミニウム、銀、ナトリウム-カリウム合金、マグネシウム/アルミニウム混合物、マグネシウム/銀混合物、マグネシウム/インジウム混合物、アルミニウム/酸化アルミニウム(Al)混合物、希土類金属等が挙げられる。これらは、単独で用いても、2種以上を組み合わせて用いてもよい。
[Cathode 3]
The cathode 3 has a function of supplying electrons from an external power source toward the light emitting layer 6.
The constituent material (cathode material) of the cathode 3 is not particularly limited, but, for example, lithium, sodium, magnesium, aluminum, silver, sodium-potassium alloy, magnesium / aluminum mixture, magnesium / silver mixture, magnesium / indium mixture, aluminum / Aluminum oxide (Al 2 O 3 ) mixture, rare earth metals, etc. may be mentioned. These may be used alone or in combination of two or more.
 陰極3の厚さは、特に限定されないが、0.1~1,000nm程度であることが好ましく、1~200nm程度であることがより好ましい。
 陰極3は、例えば、蒸着法やスパッタリング法のような乾式成膜法により形成することができる。
The thickness of the cathode 3 is not particularly limited, but is preferably about 0.1 to 1,000 nm, and more preferably about 1 to 200 nm.
The cathode 3 can be formed by, for example, a dry film forming method such as a vapor deposition method or a sputtering method.
 [正孔注入層4]
 正孔注入層4は、陽極2から供給された正孔を受け取り、正孔輸送層5に注入する機能を有する。なお、正孔注入層4は、必要に応じて設けるようにすればよく、省略することもできる。
[Hole injection layer 4]
The hole injection layer 4 has a function of receiving holes supplied from the anode 2 and injecting the holes into the hole transport layer 5. The hole injection layer 4 may be provided as necessary, and may be omitted.
 正孔注入層4の構成材料(正孔注入材料)としては、特に限定されないが、例えば、銅フタロシアニンのようなフタロシアニン化合物;4,4’,4’’-トリス[フェニル(m-トリル)アミノ]トリフェニルアミンのようなトリフェニルアミン誘導体;1,4,5,8,9,12-ヘキサアザトリフェニレンヘキサカルボニトリル、2,3,5,6-テトラフルオロ-7,7,8,8-テトラシアノ-キノジメタンのようなシアノ化合物;酸化バナジウム、酸化モリブデンのような金属酸化物;アモルファスカーボン;ポリアニリン(エメラルディン)、ポリ(3,4-エチレンジオキシチオフェン)-ポリ(スチレンスルホン酸)(PEDOT-PSS)、ポリピロールのような高分子等が挙げられる。 The constituent material (hole injection material) of the hole injection layer 4 is not particularly limited. For example, phthalocyanine compounds such as copper phthalocyanine; 4,4 ', 4' '-tris [phenyl (m-tolyl) amino] Triphenylamine derivatives such as triphenylamine; 1,4,5,8,9,12-hexaazatriphenylenehexacarbonitrile, 2,3,5,6-tetrafluoro-7,7,8,8- Cyano compounds such as tetracyano-quinodimethane; metal oxides such as vanadium oxide and molybdenum oxide; amorphous carbon; polyaniline (emeraldine), poly (3,4-ethylenedioxythiophene) -poly (styrene sulfonic acid) (PEDOT -PSS), polymers such as polypyrrole, and the like.
 これらの中でも、正孔注入材料としては、高分子であることが好ましく、PEDOT-PSSであることがより好ましい。
 また、上述の正孔注入材料は、単独で用いても、2種以上を組み合わせて用いてもよい。
Among these, the hole injection material is preferably a polymer, and more preferably PEDOT-PSS.
In addition, the above-described hole injection materials may be used alone or in combination of two or more.
 正孔注入層4の厚さは、特に限定されないが、0.1~500mm程度であることが好ましく、1~300nm程度であることがより好ましく、2~200nm程度であることがさらに好ましい。
 正孔注入層4は、単層構成であっても、2層以上が積層された積層構成であってもよい。
 このような正孔注入層4は、湿式成膜法または乾式成膜法により形成することができる。
The thickness of the hole injection layer 4 is not particularly limited, but is preferably about 0.1 to 500 mm, more preferably about 1 to 300 nm, and still more preferably about 2 to 200 nm.
The hole injection layer 4 may have a single-layer structure or a stacked structure in which two or more layers are stacked.
Such a hole injection layer 4 can be formed by a wet film formation method or a dry film formation method.
 正孔注入層4を湿式成膜法で形成する場合には、通常、上述の正孔注入材料を含有するインクを各種塗布法により塗布し、得られた塗膜を乾燥する。塗布法としては、特に限定されないが、例えば、インクジェット法(液滴吐出法)、スピンコート法、キャスト法、LB法、凸版印刷法、グラビア印刷法、スクリーン印刷法、ノズルプリント印刷法等が挙げられる。
 一方、正孔注入層4を乾式成膜法で形成する場合には、真空蒸着法、スパッタリング法等を好適に用いることができる。
When the hole injection layer 4 is formed by a wet film formation method, an ink containing the above-described hole injection material is usually applied by various coating methods, and the obtained coating film is dried. The application method is not particularly limited, and examples thereof include an inkjet method (droplet discharge method), a spin coat method, a cast method, an LB method, a letterpress printing method, a gravure printing method, a screen printing method, a nozzle printing method and the like. Be
On the other hand, when the hole injection layer 4 is formed by a dry film formation method, a vacuum evaporation method, a sputtering method or the like can be suitably used.
 [正孔輸送層5]
 正孔輸送層5は、正孔注入層4から正孔を受け取り、発光層6まで効率的に輸送する機能を有する。また、正孔輸送層4は、電子の輸送を防止する機能を有していてもよい。なお、正孔輸送層5は、必要に応じて設けるようにすればよく、省略することもできる。
[Hole Transport Layer 5]
The hole transport layer 5 has a function of receiving holes from the hole injection layer 4 and efficiently transporting the holes to the light emitting layer 6. In addition, the hole transport layer 4 may have a function of preventing transport of electrons. The hole transport layer 5 may be provided if necessary, and may be omitted.
 正孔輸送層5の構成材料(正孔輸送材料)としては、特に限定されないが、例えば、TPD(N,N’-ジフェニル-N,N’-ジ(3-メチルフェニル)-1,1’-ビフェニル-4,4’ジアミン)、α-NPD(4,4’-ビス[N-(1-ナフチル)-N-フェニルアミノ]ビフェニル)、m-MTDATA(4、4’,4’’-トリス(3-メチルフェニルフェニルアミノ)トリフェニルアミン)のような低分子トリフェニルアミン誘導体;ポリビニルカルバゾール;ポリ[N,N’-ビス(4-ブチルフェニル)-N,N’-ビス(フェニル)-ベンジジン](poly-TPA)、ポリフルオレン(PF)、ポリ[N,N’-ビス(4-ブチルフェニル)-N,N’-ビス(フェニル)-ベンジジン(Poly-TPD)、ポリ[(9,9-ジオクチルフルオレニル-2,7-ジイル)-コー(4,4’-(N-(sec-ブチルフェニル)ジフェニルアミン))(TFB)、ポリフェニレンビニレン(PPV)のような共役系化合物重合体;およびこれらのモノマー単位を含む共重合体等が挙げられる。 The constituent material (hole transport material) of the hole transport layer 5 is not particularly limited, and, for example, TPD (N, N'-diphenyl-N, N'-di (3-methylphenyl) -1, 1 ' -Biphenyl-4,4'diamine), α-NPD (4,4'-bis [N- (1-naphthyl) -N-phenylamino] biphenyl), m-MTDATA (4,4 ', 4' '-) Low molecular weight triphenylamine derivatives such as tris (3-methylphenylphenylamino) triphenylamine); polyvinylcarbazole; poly [N, N'-bis (4-butylphenyl) -N, N'-bis (phenyl) -Benzidine] (poly-TPA), polyfluorene (PF), poly [N, N'-bis (4-butylphenyl) -N, N'-bis (phenyl) -benzidine (Poly-TPD), [(9,9-Dioctylfluorenyl-2,7-diyl) -co (4,4 '-(N- (sec-butylphenyl) diphenylamine)) (TFB), such as polyphenylene vinylene (PPV) Conjugated compound polymers; copolymers containing these monomer units, and the like can be mentioned.
 これらの中でも、正孔輸送材料としては、トリフェニルアミン誘導体、置換基が導入されたトリフェニルアミン誘導体を重合することにより得られた高分子化合物であることが好ましく、置換基が導入されたトリフェニルアミン誘導体を重合することにより得られた高分子化合物であることがより好ましい。
 また、上述の正孔輸送材料は、単独で用いても、2種以上を組み合わせて用いてもよい。
Among these, the hole transport material is preferably a triphenylamine derivative, or a polymer compound obtained by polymerizing a triphenylamine derivative having a substituent introduced therein, and the substituent having a substituent introduced therein is preferable. More preferably, it is a polymer compound obtained by polymerizing a phenylamine derivative.
The above-mentioned hole transport materials may be used alone or in combination of two or more.
 正孔輸送層5の厚さは、特に限定されないが、1~500nm程度であることが好ましく、5~300nm程度であることがより好ましく、10~200nm程度であることがさらに好ましい。
 正孔輸送層5は、単層構成であっても、2層以上が積層された積層構成であってもよい。
 このような正孔輸送層5は、湿式成膜法または乾式成膜法により形成することができる。
The thickness of the hole transport layer 5 is not particularly limited, but is preferably about 1 to 500 nm, more preferably about 5 to 300 nm, and still more preferably about 10 to 200 nm.
The hole transport layer 5 may have a single-layer structure or a stacked structure in which two or more layers are stacked.
Such a hole transport layer 5 can be formed by a wet film formation method or a dry film formation method.
 正孔輸送層5を湿式成膜法で形成する場合には、通常、上述の正孔輸送材料を含有するインクを各種塗布法により塗布し、得られた塗膜を乾燥する。塗布法としては、特に限定されないが、例えば、インクジェット法(液滴吐出法)、スピンコート法、キャスト法、LB法、凸版印刷法、グラビア印刷法、スクリーン印刷法、ノズルプリント印刷法等が挙げられる。
 一方、正孔輸送層5を乾式成膜法で形成する場合には、真空蒸着法、スパッタリング法等を好適に用いることができる。
When the hole transport layer 5 is formed by a wet film formation method, generally, the ink containing the above-mentioned hole transport material is applied by various coating methods, and the obtained coating film is dried. The application method is not particularly limited, and examples thereof include an inkjet method (droplet discharge method), a spin coat method, a cast method, an LB method, a letterpress printing method, a gravure printing method, a screen printing method, a nozzle printing method and the like. Be
On the other hand, when the hole transport layer 5 is formed by a dry film formation method, a vacuum evaporation method, a sputtering method or the like can be suitably used.
 [電子注入層8]
 電子注入層8は、陰極3から供給された電子を受け取り、電子輸送層7に注入する機能を有する。なお、電子注入層8は、必要に応じて設けるようにすればよく、省略することもできる。
[Electron injection layer 8]
The electron injection layer 8 has a function of receiving the electrons supplied from the cathode 3 and injecting the electrons into the electron transport layer 7. The electron injection layer 8 may be provided if necessary, and can be omitted.
 電子注入層8の構成材料(電子注入材料)としては、特に制限されないが、例えば、LiO、LiO、NaS、NaSe、NaOのようなアルカリ金属カルコゲナイド;CaO、BaO、SrO、BeO、BaS、MgO、CaSeのようなアルカリ土類金属カルコゲナイド;CsF、LiF、NaF、KF、LiCl、KCl、NaClのようなアルカリ金属ハライド;8-ヒドロキシキノリノラトリチウム(Liq)のようなアルカリ金属塩;CaF、BaF、SrF、MgF、BeFのようなアルカリ土類金属ハライド等が挙げられる。 The constituent material (electron injection material) of the electron injection layer 8 is not particularly limited, but, for example, alkali metal chalcogenides such as Li 2 O, LiO, Na 2 S, Na 2 Se, NaO; CaO, BaO, SrO, Alkaline earth metal chalcogenides such as BeO, BaS, MgO, CaSe; alkali metal halides such as CsF, LiF, NaF, KF, LiCl, KCl, NaCl; alkalis such as 8-hydroxyquinolinolatolithium (Liq) Metal salts; alkaline earth metal halides such as CaF 2 , BaF 2 , SrF 2 , MgF 2 , BeF 2 and the like can be mentioned.
 これらの中でも、アルカリ金属カルコゲナイド、アルカリ土類金属ハライド、アルカリ金属塩であることが好ましい。
 また、上述の電子注入材料は、単独で用いても、2種以上を組み合わせて用いてもよい。
Among these, alkali metal chalcogenides, alkaline earth metal halides and alkali metal salts are preferable.
In addition, the above-mentioned electron injection materials may be used alone or in combination of two or more.
 電子注入層8の厚さは、特に限定されないが、0.1~100nm程度であることが好ましく、0.2~50nm程度であることがより好ましく、0.5~10nm程度であることがさらに好ましい。
 電子注入層8は、単層構成であっても、2層以上が積層された積層構成であってもよい。
 このような電子注入層8は、湿式成膜法または乾式成膜法により形成することができる。
The thickness of the electron injection layer 8 is not particularly limited, but is preferably about 0.1 to 100 nm, more preferably about 0.2 to 50 nm, and still more preferably about 0.5 to 10 nm. preferable.
The electron injection layer 8 may have a single-layer structure or a stacked structure in which two or more layers are stacked.
Such an electron injection layer 8 can be formed by a wet film formation method or a dry film formation method.
 電子注入層8を湿式成膜法で形成する場合には、通常、上述の電子注入材料を含有するインクを各種塗布法により塗布し、得られた塗膜を乾燥する。塗布法としては、特に限定されないが、例えば、インクジェット法(液滴吐出法)、スピンコート法、キャスト法、LB法、凸版印刷法、グラビア印刷法、スクリーン印刷法、ノズルプリント印刷法等が挙げられる。
 一方、電子注入層8を乾式成膜法で形成する場合には、真空蒸着法、スパッタリング法等が適用されうる。
When the electron injection layer 8 is formed by a wet film formation method, generally, the ink containing the above-mentioned electron injection material is applied by various coating methods, and the obtained coating film is dried. The application method is not particularly limited, and examples thereof include an inkjet method (droplet discharge method), a spin coat method, a cast method, an LB method, a letterpress printing method, a gravure printing method, a screen printing method, a nozzle printing method and the like. Be
On the other hand, when the electron injection layer 8 is formed by a dry film formation method, a vacuum evaporation method, a sputtering method, or the like can be applied.
 [電子輸送層7]
 電子輸送層7は、電子注入層8から電子を受け取り、発光層6まで効率的に輸送する機能を有する。また、電子輸送層7は、正孔の輸送を防止する機能を有していてもよい。なお、電子輸送層7は、必要に応じて設けるようにすればよく、省略することもできる。
[Electron transport layer 7]
The electron transport layer 7 has a function of receiving electrons from the electron injection layer 8 and efficiently transporting it to the light emitting layer 6. In addition, the electron transport layer 7 may have a function of preventing the transport of holes. The electron transport layer 7 may be provided as necessary, and may be omitted.
 電子輸送層7の構成材料(電子輸送材料)としては、特に制限されないが、例えば、トリス(8-キノリラート)アルミニウム(Alq3)、トリス(4-メチル-8-キノリノラート)アルミニウム(Almq3)、ビス(10-ヒドロキシベンゾ[h]キノリナート)ベリリウム(BeBq2)、ビス(2-メチル-8-キノリノラート)(p-フェニルフェノラート)アルミニウム(BAlq)、ビス(8-キノリノラート)亜鉛(Znq)のようなキノリン骨格またはベンゾキノリン骨格を有する金属錯体;ビス[2-(2’-ヒドロキシフェニル)ベンズオキサゾラート]亜鉛(Zn(BOX)2)のようなベンズオキサゾリン骨格を有する金属錯体;ビス[2-(2’-ヒドロキシフェニル)ベンゾチアゾラート]亜鉛(Zn(BTZ)2)のようなベンゾチアゾリン骨格を有する金属錯体;2-(4-ビフェニリル)-5-(4-tert-ブチルフェニル)-1,3,4-オキサジアゾール(PBD)、3-(4-ビフェニリル)-4-フェニル-5-(4-tert-ブチルフェニル)-1,2,4-トリアゾール(TAZ)、1,3-ビス[5-(p-tert-ブチルフェニル)-1,3,4-オキサジアゾール-2-イル]ベンゼン(OXD-7)、9-[4-(5-フェニル-1,3,4-オキサジアゾール-2-イル)フェニル]カルバゾール(CO11)のようなトリまたはジアゾール誘導体;2,2’,2’’-(1,3,5-ベンゼントリイル)トリス(1-フェニル-1H-ベンゾイミダゾール)(TPBI)、2-[3-(ジベンゾチオフェン-4-イル)フェニル]-1-フェニル-1H-ベンゾイミダゾール(mDBTBIm-II)のようなイミダゾール誘導体;キノリン誘導体;ペリレン誘導体;4,7-ジフェニル-1,10-フェナントロリン(BPhen)のようなピリジン誘導体;ピリミジン誘導体;トリアジン誘導体;キノキサリン誘導体;ジフェニルキノン誘導体;ニトロ置換フルオレン誘導体;酸化亜鉛(ZnO)、酸化チタン(TiO)のような金属酸化物等が挙げられる。 The constituent material (electron transport material) of the electron transport layer 7 is not particularly limited. For example, tris (8-quinolate) aluminum (Alq3), tris (4-methyl-8-quinolinolato) aluminum (Almq3), bis ( Quinoline such as 10-hydroxybenzo [h] quinolinate) beryllium (BeBq2), bis (2-methyl-8-quinolinolato) (p-phenylphenolate) aluminum (BAlq), bis (8-quinolinolato) zinc (Znq) A metal complex having a skeleton or a benzoquinoline skeleton; a metal complex having a benzoxazoline skeleton such as bis [2- (2′-hydroxyphenyl) benzoxazolato] zinc (Zn (BOX) 2); 2'-Hydroxyphenyl) benzothiazolate] zinc (Zn (B (B) Z) Metal complexes having a benzothiazoline skeleton as in 2); 2- (4-biphenylyl) -5- (4-tert-butylphenyl) -1,3,4-oxadiazole (PBD), 3- ( 4-biphenylyl) -4-phenyl-5- (4-tert-butylphenyl) -1,2,4-triazole (TAZ), 1,3-bis [5- (p-tert-butylphenyl) -1, 3,4-Oxadiazol-2-yl] benzene (OXD-7), 9- [4- (5-phenyl-1,3,4-oxadiazol-2-yl) phenyl] carbazole (CO11) Such as tri or diazole derivatives; 2,2 ′, 2 ′ ′-(1,3,5-benzenetriyl) tris (1-phenyl-1H-benzoimidazole) (TPBI), 2- [3- (dibenzothiophene) -4 Imidazole derivatives such as -yl) phenyl] -1-phenyl-1H-benzoimidazole (mDBTBIm-II); quinoline derivatives; perylene derivatives; pyridine derivatives such as 4,7-diphenyl-1,10-phenanthroline (BPhen) Pyrimidine derivatives; triazine derivatives; quinoxaline derivatives; diphenylquinone derivatives; nitro-substituted fluorene derivatives; metal oxides such as zinc oxide (ZnO), titanium oxide (TiO 2 ), and the like.
 これらの中でも、電子輸送材料としては、イミダゾール誘導体、ピリジン誘導体、ピリミジン誘導体、トリアジン誘導体、金属酸化物(無機酸化物)であることが好ましい。
 また、上述の電子輸送材料は、単独で用いても、2種以上を組み合わせて用いてもよい。
 電子輸送層7の厚さは、特に限定されないが、5~500nm程度であることが好ましく、5~200nm程度であることがより好ましい。
 電子輸送層7は、単層であっても、2以上が積層されたものであってもよい。
 このような電子輸送層7は、湿式成膜法または乾式成膜法により形成することができる。
Among these, as an electron transport material, it is preferable that they are an imidazole derivative, a pyridine derivative, a pyrimidine derivative, a triazine derivative, and a metal oxide (inorganic oxide).
In addition, the above-mentioned electron transporting materials may be used alone or in combination of two or more.
The thickness of the electron transport layer 7 is not particularly limited, but is preferably about 5 to 500 nm, and more preferably about 5 to 200 nm.
The electron transport layer 7 may be a single layer or a stack of two or more.
Such an electron transport layer 7 can be formed by a wet film formation method or a dry film formation method.
 電子輸送層7を湿式成膜法で形成する場合には、通常、上述の電子輸送材料を含有するインクを各種塗布法により塗布し、得られた塗膜を乾燥する。塗布法としては、特に限定されないが、例えば、インクジェット法(液滴吐出法)、スピンコート法、キャスト法、LB法、凸版印刷法、グラビア印刷法、スクリーン印刷法、ノズルプリント印刷法等が挙げられる。
 一方、電子輸送層7を乾式成膜法で形成する場合には、真空蒸着法、スパッタリング法等が適用されうる。
When the electron transport layer 7 is formed by a wet film formation method, generally, the ink containing the above-mentioned electron transport material is applied by various coating methods, and the obtained coating film is dried. The application method is not particularly limited, and examples thereof include an inkjet method (droplet discharge method), a spin coat method, a cast method, an LB method, a letterpress printing method, a gravure printing method, a screen printing method, a nozzle printing method and the like. Be
On the other hand, when the electron transport layer 7 is formed by a dry film formation method, a vacuum evaporation method, a sputtering method or the like may be applied.
 [発光層6]
 発光層6は、発光層6に注入された正孔および電子の再結合により生じるエネルギーを利用して発光を生じさせる機能を有する。
 発光層6は、本発明のインクの乾燥物で構成される。したがって、発光層6中には、ナノ結晶が均一に分散して存在するため、発光層6は、優れた発光効率を有する。
[Light emitting layer 6]
The light emitting layer 6 has a function of generating light emission using energy generated by recombination of holes and electrons injected into the light emitting layer 6.
The light emitting layer 6 is composed of the dried product of the ink of the present invention. Therefore, since the nanocrystals are uniformly dispersed and present in the light emitting layer 6, the light emitting layer 6 has excellent light emitting efficiency.
 発光層6の厚さは、特に限定されないが、1~100nm程度であることが好ましく、1~50nm程度であることがより好ましい。
 発光層8は、本発明のインクを各種塗布法により塗布し、得られた塗膜を乾燥する。塗布法としては、特に限定されないが、例えば、インクジェット印刷法(ピエゾ方式またはサーマル方式の液滴吐出法)、スピンコート法、キャスト法、LB法、凸版印刷法、グラビア印刷法、スクリーン印刷法、ノズルプリント印刷法等が挙げられる。
 ここで、ノズルプリント印刷法とは、インクをノズル孔から液柱としてストライプ状に塗布する方法である。
The thickness of the light emitting layer 6 is not particularly limited, but is preferably about 1 to 100 nm, and more preferably about 1 to 50 nm.
The light emitting layer 8 applies the ink of this invention by various coating methods, and dries the obtained coating film. The coating method is not particularly limited, and examples thereof include inkjet printing (piezo method or thermal droplet discharge method), spin coating, casting, LB method, letterpress printing, gravure printing, screen printing, The nozzle printing method etc. are mentioned.
Here, the nozzle printing method is a method of applying ink in the form of stripes from the nozzle holes as liquid columns.
 本発明のインクは、インクジェット印刷法により好適に塗布することができる。特に、本発明のインクは、ピエゾ方式のインクジェット印刷法により塗布することが好ましい。これにより、インクを吐出する際の熱負荷を小さくすることができ、ナノ結晶自体に不具合が発生し難い。したがって、本発明のインクの塗布に用いる好適な装置は、ピエゾ方式のインクジェットヘッドを有するインクジェットプリンターである。 The ink of the present invention can be suitably applied by inkjet printing. In particular, the ink of the present invention is preferably applied by a piezo inkjet printing method. As a result, the thermal load at the time of discharging the ink can be reduced, and a defect does not easily occur in the nanocrystal itself. Therefore, a preferred apparatus used for applying the ink of the present invention is an inkjet printer having a piezo inkjet head.
 なお、発光素子1は、さらに、例えば、正孔注入層4、正孔輸送層5および発光層6を区画するバンク(隔壁)を有していてもよい。
 バンクの高さは、特に限定されないが、0.1~5μm程度であることが好ましく、0.2~4μm程度であることがより好ましく、0.2~3μm程度であることがさらに好ましい。
The light emitting element 1 may further include, for example, a bank (partition wall) that divides the hole injection layer 4, the hole transport layer 5, and the light emitting layer 6.
The height of the bank is not particularly limited, but is preferably about 0.1 to 5 μm, more preferably about 0.2 to 4 μm, and still more preferably about 0.2 to 3 μm.
 バンクの開口の幅は、10~200μm程度であることが好ましく、30~200μm程度であることがより好ましく、50~100μm程度であることがさらに好ましい。
 バンクの開口の長さは、10~400μm程度であることが好ましく、20~200μm程度であることがより好ましく、50~200μm程度であることがさらに好ましい。
 また、バンクの傾斜角度は、10~100°程度であることが好ましく、10~90°程度であることがより好ましく、10~80°程度であることがさらに好ましい。
The width of the bank opening is preferably about 10 to 200 μm, more preferably about 30 to 200 μm, and still more preferably about 50 to 100 μm.
The length of the opening of the bank is preferably about 10 to 400 μm, more preferably about 20 to 200 μm, and still more preferably about 50 to 200 μm.
The inclination angle of the bank is preferably about 10 to 100 °, more preferably about 10 to 90 °, and still more preferably about 10 to 80 °.
 <発光素子の製造方法>
 発光素子の製造方法は、前述したようなインクを支持体上に供給して塗膜を形成し、塗膜を乾燥することにより発光層を形成する工程(以下、「発光層形成工程」とも称する)を有している。
 支持体は、図1に示す構成では、正孔輸送層5または電子輸送層7であるが、製造目的の発光素子によって異なる。
<Method of manufacturing light emitting device>
The method of manufacturing a light emitting device is a step of forming a light emitting layer by supplying an ink as described above onto a support to form a coated film, and drying the coated film (hereinafter also referred to as "light emitting layer forming step" )have.
The support is the hole transport layer 5 or the electron transport layer 7 in the configuration shown in FIG. 1, but it differs depending on the light emitting element to be manufactured.
 例えば、陽極、正孔輸送層、発光層および陰極で構成される発光素子を製造する場合には、支持体は、正孔輸送層または陰極である。また、陽極、正孔注入層、発光層、電子注入層および陰極で構成される発光素子を製造する場合には、支持体は、正孔注入層または電子注入層である。
 このように、支持体としては、陽極、正孔注入層、正孔輸送層、電子輸送層、電子注入層または陰極であり得る。なお、支持体は、好ましくは陽極、正孔注入層または正孔輸送層であり、より好ましくは正孔注入層または正孔輸送層であり、さらに好ましくは正孔輸送層である。
For example, in the case of producing a light emitting device composed of an anode, a hole transport layer, a light emitting layer and a cathode, the support is a hole transport layer or a cathode. In the case of producing a light emitting device composed of an anode, a hole injection layer, a light emitting layer, an electron injection layer and a cathode, the support is a hole injection layer or an electron injection layer.
Thus, the support may be an anode, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection layer or a cathode. The support is preferably an anode, a hole injection layer or a hole transport layer, more preferably a hole injection layer or a hole transport layer, and still more preferably a hole transport layer.
 なお、支持体には、前述したようなバンクを形成してもよい。バンクを形成することにより、支持体上の所望の箇所にのみ発光層6を形成することができる。
 例えば、液滴吐出法では、本発明のインクを液滴吐出ヘッドのノズル孔から間欠的に支持体上に所定のパターンで吐出する。液滴吐出法によれば、高い自由度で描画パターニングを行うことができる。中でも、ピエゾ方式の液滴吐出法によれば、分散媒の選択性を高めることができるとともに、インクに対する熱負荷を低減することができる。
The above-mentioned bank may be formed on the support. By forming the bank, the light emitting layer 6 can be formed only at a desired position on the support.
For example, in the droplet discharge method, the ink of the present invention is intermittently discharged from the nozzle holes of the droplet discharge head onto the support in a predetermined pattern. According to the droplet discharge method, drawing patterning can be performed with a high degree of freedom. Above all, according to the piezoelectric droplet discharge method, the selectivity of the dispersion medium can be enhanced, and the heat load on the ink can be reduced.
 この際、インクの吐出量は、特に限定されないが、1~50pL/回であることが好ましく、1~30pL/回であることがより好ましく、1~20pL/回であることがさらに好ましい。
 また、ノズル孔の開口径は、5~50μm程度であることが好ましく、10~30μm程度であることがより好ましい。これにより、ノズル孔の目詰まりを防止しつつ、吐出精度を高めることができる。
At this time, the ejection amount of the ink is not particularly limited, but is preferably 1 to 50 pL / time, more preferably 1 to 30 pL / time, and still more preferably 1 to 20 pL / time.
Further, the opening diameter of the nozzle hole is preferably about 5 to 50 μm, and more preferably about 10 to 30 μm. Thus, the discharge accuracy can be enhanced while preventing clogging of the nozzle holes.
 塗膜を形成する際の温度は、特に限定されないが、10~50℃程度であることが好ましく、15~40℃程度であることがより好ましく、15~30℃程度であることがさらに好ましい。かかる温度で液滴を吐出するようにすれば、インク中に含まれる各種成分((ナノ結晶、分散剤、電荷輸送材料等)の結晶化を抑制することができる。 The temperature for forming the coating film is not particularly limited, but is preferably about 10 to 50 ° C., more preferably about 15 to 40 ° C., and still more preferably about 15 to 30 ° C. By discharging droplets at such a temperature, crystallization of various components (such as nanocrystals, dispersants, charge transport materials, and the like) contained in the ink can be suppressed.
 また、塗膜を形成する際の相対湿度も、特に限定されないが、0.01ppm~80%程度であることが好ましく、0.05ppm~60%程度であることがより好ましく、0.1ppm~15%程度であることがさらに好ましく、1ppm~1%程度であることが特に好ましく、5~100ppm程度であることが最も好ましい。
 相対湿度が前記下限値以上であると、塗膜を形成する際の条件の制御が容易となることから好ましい。一方、相対湿度が前記上限値以下であると、得られる発光層6に悪影響を及ぼし得る塗膜に吸着する水分量を低減することができることから好ましい。
Also, the relative humidity at the time of forming the coating film is not particularly limited, but is preferably about 0.01 ppm to 80%, more preferably about 0.05 ppm to 60%, and more preferably 0.1 ppm to 15 % Is more preferable, 1 ppm to 1% is particularly preferable, and 5 to 100 ppm is most preferable.
It is preferable from the control of the conditions at the time of forming a coating film becoming easy for relative humidity to be more than the said lower limit. On the other hand, it is preferable from the ability to reduce the moisture content adsorbed to the coating film which may exert a bad influence on the light emitting layer 6 obtained as relative humidity is below the said upper limit.
 得られた塗膜を乾燥することにより、発光層6が得られる
 乾燥は、室温(25℃)で放置して行っても、加熱することにより行ってもよい。乾燥を加熱により行う場合、乾燥温度は、特に限定されないが、40~150℃程度であることが好ましく、40~120℃程度であることがより好ましい。
The light-emitting layer 6 is obtained by drying the obtained coated film. Drying may be performed by leaving at room temperature (25 ° C.) or by heating. When drying is performed by heating, the drying temperature is not particularly limited, but is preferably about 40 to 150 ° C., and more preferably about 40 to 120 ° C.
 また、乾燥は、減圧下で行うことが好ましく、0.001~100Paの減圧下で行うことがより好ましい。
 さらに、乾燥時間は、1~90分であることが好ましく、1~30分であることがより好ましい。
In addition, drying is preferably performed under reduced pressure, and more preferably performed under reduced pressure of 0.001 to 100 Pa.
Furthermore, the drying time is preferably 1 to 90 minutes, and more preferably 1 to 30 minutes.
 以上、本発明のインクおよび発光素子について説明したが、本発明は、前述した実施形態の構成に限定されるものではない。
 例えば、本発明のインクおよび発光素子は、それぞれ、前述した実施形態に構成において、他の任意の構成を追加して有していてもよいし、同様の機能を発揮する任意の構成と置換されていてよい。
As mentioned above, although the ink and light emitting element of this invention were demonstrated, this invention is not limited to the structure of embodiment mentioned above.
For example, the ink and the light emitting element of the present invention may have any other optional configuration added to the configuration of the above-described embodiment, or may be replaced with any configuration that exhibits the same function. You may
 以下、実施例を挙げて本発明を具体的に説明するが、本発明はこれらに限定されるものではない。
 1.ET-1、ET-2およびET-5の合成
 <ET-1の合成>
EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but the present invention is not limited thereto.
1. Synthesis of ET-1, ET-2 and ET-5 <Synthesis of ET-1>
Figure JPOXMLDOC01-appb-C000011
Figure JPOXMLDOC01-appb-C000011
 75mLのTHFと50mLのトルエンとの混合溶液に、2.7g(11.0mmol)の3-ブロモカルバゾールと、5.1g(12.1mmol)の9-(4-tert-ブチル)フェニル)-3-(4,4,5,5―テトラメチル-1,3,2-ジオキサボロラン-2-イル)カルバゾールと、0.14g(0.12mmol)のテトラキス(トリフェニルホスフィン)パラジウム(0)とを加えて撹拌し、次いで、3.3g(24.1mmol)の炭酸カリウムを溶解させた水30mLを加えて、混合物を得た。この混合物を12時間撹拌しながら加熱還流させ、室温まで冷却した後、混合物に水とクロロホルムとを加えて分液させ、クロロホルム層を回収した。回収したクロロホルム層を食塩水、硫酸マグネシウムにより脱水処理後、クロロホルムを減圧留去して、残留物を得た。次いで、この残留物をカラムクロマトグラフィーにより精製することで、3.2g(6.8mmol)の中間体1を得た(収率62%)。 In a mixed solution of 75 mL of THF and 50 mL of toluene, 2.7 g (11.0 mmol) of 3-bromocarbazole and 5.1 g (12.1 mmol) of 9- (4-tert-butyl) phenyl) -3 -(4,4,5,5-Tetramethyl-1,3,2-dioxaborolan-2-yl) carbazole and 0.14 g (0.12 mmol) of tetrakis (triphenylphosphine) palladium (0) are added. The mixture was stirred and then 30 mL of water containing 3.3 g (24.1 mmol) of potassium carbonate dissolved therein was added to obtain a mixture. The mixture was heated to reflux with stirring for 12 hours, cooled to room temperature, water and chloroform were added to the mixture, the phases were separated, and the chloroform layer was recovered. The collected chloroform layer was dehydrated with brine and magnesium sulfate, and then chloroform was evaporated under reduced pressure to obtain a residue. Then, the residue was purified by column chromatography to obtain 3.2 g (6.8 mmol) of Intermediate 1 (yield 62%).
 30mLのトルエンと、30mLのジオキサンと、30mLの水との混合溶液に、3.2g(6.8mmol)の中間体1と、2.6g(6.8mmol)の2-(4-ブロモフェニル)-4,6-ジフェニル-1,3,5-トリアジンと、5.8g(27.2mmol)のリン酸三カリウムと、0.12g(0.40mmol)のトリ(o-トリル)ホスフィンと、0.018g(0.080mmol)の酢酸パラジウム(II)とを加えて、混合物を得、この混合物を16時間加熱還流させた。混合物を室温冷却した後、混合物に水と酢酸エチルとを加えて分液させ、酢酸エチル層を回収した。回収した酢酸エチル層を食塩水、硫酸マグネシウムにより脱水処理後、酢酸エチルを減圧留去して、残留物を得た。次いで、この残留物をカラムクロマトグラフィーにより精製することで、2.3g(2.9mmol)のET-1を得た(収率43%)。 In a mixed solution of 30 mL of toluene, 30 mL of dioxane, and 30 mL of water, 3.2 g (6.8 mmol) of intermediate 1 and 2.6 g (6.8 mmol) of 2- (4-bromophenyl) 0-4,6-diphenyl-1,3,5-triazine, 5.8 g (27.2 mmol) of tripotassium phosphate, 0.12 g (0.40 mmol) of tri (o-tolyl) phosphine, 0 .018 g (0.080 mmol) of palladium (II) acetate were added to obtain a mixture, and the mixture was heated to reflux for 16 hours. The mixture was cooled to room temperature, water and ethyl acetate were added to the mixture to separate it, and the ethyl acetate layer was recovered. The collected ethyl acetate layer was dehydrated with brine and magnesium sulfate, and then ethyl acetate was distilled off under reduced pressure to obtain a residue. Then, the residue was purified by column chromatography to obtain 2.3 g (2.9 mmol) of ET-1 (yield 43%).
 <ET-2の合成> <Synthesis of ET-2>
Figure JPOXMLDOC01-appb-C000012
Figure JPOXMLDOC01-appb-C000012
 30mLのキシレンに、2.0g(7.8mmol)の(5,11-ジヒドロインドロ[3,2-b]カルバゾールと、1.3g(8.6mmol)のブロモベンゼンと、0.07g(0.08mmol)のトリス(ジベンジリデンアセトン)ジパラジウム(0)と、0.03g(0.17mmol)のトリ(tert-ブチル)ホスフィンとを加えて撹拌し、次いで、0.45g(4.7mmol)のナトリウムtert-ブトキシドを加えて、混合物を得た。この混合物を16時間加熱還流させた後、室温まで冷却し、混合物に水と酢酸エチルとを加えて分液させた。酢酸エチル層を回収し、回収した酢酸エチル層を食塩水、硫酸マグネシウムにより脱水処理後、酢酸エチルを減圧留去して、残留物を得た。次いで、この残留物をカラムクロマトグラフィーにより精製することで、2.1g(6.2mmol)の中間体2を得た(収率80%)。 In 30 mL of xylene, 2.0 g (7.8 mmol) of (5,11-dihydroindolo [3,2-b] carbazole, 1.3 g (8.6 mmol) of bromobenzene and 0.07 g (0 .08 mmol) of tris (dibenzylideneacetone) dipalladium (0) and 0.03 g (0.17 mmol) of tri (tert-butyl) phosphine are added and stirred, and then 0.45 g (4.7 mmol) Sodium tert-butoxide was added to give a mixture, which was heated to reflux for 16 hours, cooled to room temperature, water and ethyl acetate were added to the mixture, and the ethyl acetate layer was recovered. The collected ethyl acetate layer was dehydrated with brine and magnesium sulfate, and then ethyl acetate was distilled off under reduced pressure to give a residue. Purification by chromatography to give the intermediate 2 2.1g (6.2mmol) (80% yield).
 30mLのトルエンと、30mLのジオキサンと、30mLの水との混合溶液に、2.1g(6.2mmol)の中間体2と、6.0g(7.5mmol)の2-クロロ-4,6-ビス-(3-([3,1’;5,1’’]-テルフェン-1-イル)フェン-1-イル)-1,3,5-トリアジンと、5.3g(25.0mmol)のリン酸三カリウムと、0.11g(0.37mmol)のトリ(o-トリル)ホスフィンと、0.016g(0.073mmol)の酢酸パラジウム(II)とを加えて、混合物を得、この混合物を16時間加熱還流させた。混合物を室温まで冷却した後、混合物に水と酢酸エチルとを加えて分液させ、酢酸エチル層を回収した。回収した酢酸エチル層を食塩水、硫酸マグネシウムにより脱水処理後、酢酸エチルを減圧留去して、残留物を得た。次いで、この残留物をカラムクロマトグラフィーにより精製することで、2.6g(2.4mmol)のET-2を得た(収率38%)。 In a mixed solution of 30 mL of toluene, 30 mL of dioxane, and 30 mL of water, 2.1 g (6.2 mmol) of intermediate 2 and 6.0 g (7.5 mmol) of 2-chloro-4,6- Bis- (3-([3,1 ′; 5,1 ′ ′]-terphen-1-yl) phen-1-yl) -1,3,5-triazine and 5.3 g (25.0 mmol) of Tripotassium phosphate, 0.11 g (0.37 mmol) of tri (o-tolyl) phosphine and 0.016 g (0.073 mmol) of palladium (II) acetate are added to give a mixture, which is the mixture Heat to reflux for 16 hours. After the mixture was cooled to room temperature, water and ethyl acetate were added to the mixture to separate it, and the ethyl acetate layer was recovered. The collected ethyl acetate layer was dehydrated with brine and magnesium sulfate, and then ethyl acetate was distilled off under reduced pressure to obtain a residue. Then, the residue was purified by column chromatography to obtain 2.6 g (2.4 mmol) of ET-2 (yield 38%).
 <ET-5の合成> <Synthesis of ET-5>
Figure JPOXMLDOC01-appb-C000013
Figure JPOXMLDOC01-appb-C000013
 100mLの脱水THFに、10.0g(54.2mmol)のシアヌル酸クロリドと、226mL(113.0mmol)の4-tert-ブチルフェニルマグネシウムブロミド(0.5M,THF溶液)とを加え、撹拌させながら12時間加熱還流させて、反応液を得た。反応液を室温まで冷却した後、反応液に水、ジクロロメタンを加えて分液し、ジクロロメタン層を回収した。回収したジクロロメタン層を食塩水、硫酸マグネシウムにより脱水処理後、ジクロロメタンを減圧留去して、残留物を得た。次いで、この残留物をカラムクロマトグラフィーにより精製することで、10.3g(27.1mmol)の中間体3を得た(収率50%)。 In 100 mL of dehydrated THF, 10.0 g (54.2 mmol) of cyanuric chloride and 226 mL (113.0 mmol) of 4-tert-butylphenylmagnesium bromide (0.5 M solution in THF) are added and stirred. The mixture was heated to reflux for 12 hours to obtain a reaction solution. The reaction solution was cooled to room temperature, water and dichloromethane were added to the reaction solution to separate it, and the dichloromethane layer was recovered. The collected dichloromethane layer was dehydrated with brine and magnesium sulfate, and then the dichloromethane was distilled off under reduced pressure to obtain a residue. Then, the residue was purified by column chromatography to obtain 10.3 g (27.1 mmol) of Intermediate 3 (yield 50%).
 20mLの脱水THFに、0.8g(34mmol)の活性マグネシウムと、5.8g(31.6mmol)の3-ブロモスチレンとを加え、撹拌させながら3時間加熱還流させて、反応液を得た。反応液を室温まで冷却した後、10.0g(26.3mmol)の中間体3を反応液に加え、撹拌させながら12時間加熱還流させた。反応液を室温まで冷却した後、反応液に水、ジクロロメタンを加えて分液し、ジクロロメタン層を回収した。回収したジクロロメタン層を食塩水、硫酸マグネシウムにより脱水処理後、ジクロロメタンを減圧留去して、残留物を得た。次いで、この残留物をカラムクロマトグラフィーにより精製することで、8.5g(19.0mmol)の中間体4を得た(収率72%)。 0.8 g (34 mmol) of active magnesium and 5.8 g (31.6 mmol) of 3-bromostyrene were added to 20 mL of dehydrated THF, and the mixture was heated under reflux while stirring for 3 hours to obtain a reaction solution. The reaction solution was cooled to room temperature, 10.0 g (26.3 mmol) of Intermediate 3 was added to the reaction solution, and the mixture was heated to reflux for 12 hours while stirring. The reaction solution was cooled to room temperature, water and dichloromethane were added to the reaction solution to separate it, and the dichloromethane layer was recovered. The collected dichloromethane layer was dehydrated with brine and magnesium sulfate, and then the dichloromethane was distilled off under reduced pressure to obtain a residue. Then, the residue was purified by column chromatography to obtain 8.5 g (19.0 mmol) of Intermediate 4 (yield 72%).
 100mLのTHFに、5.0gの中間体4を加えて撹拌し、さらに0.1mol%のアゾビスイソブチロニトリル(AIBN)を加えて12時間加熱還流させて、反応液を得た。得られた反応液をメタノールに加えて反応物を沈殿させ、ろ過することで、4.1gのET-5を得た。 In 100 mL of THF, 5.0 g of Intermediate 4 was added and stirred, and then 0.1 mol% of azobisisobutyronitrile (AIBN) was added and the mixture was heated under reflux for 12 hours to obtain a reaction solution. The resulting reaction solution was added to methanol to precipitate a reaction, which was filtered to obtain 4.1 g of ET-5.
 2.インクの調製
 (実施例1)
 1.9mLのトルエンに、20mgの上記ET-1で示される化合物(電荷輸送材料)と、1mLの粒子を含有するトルエン溶液(5mg/mL、Aldrich社製;製品番号776785-5ML)とを混合することにより、インクを調製した。なお、粒子は、ZnSのシェルとInPのコアとを備えるナノ結晶と、それに担持されたオレイルアミンとからなる。
 (実施例2)
 上記ET-1で示される化合物を上記ET-2で示される化合物に変更したこと以外は、前記実施例1と同様にして、インクを調製した。
2. Preparation of Ink (Example 1)
In 1.9 mL of toluene, 20 mg of the compound represented by the above ET-1 (charge transporting material) and a toluene solution (5 mg / mL, manufactured by Aldrich; product number 776785-5 ML) containing 1 mL of particles are mixed. The ink was prepared by The particles are composed of nanocrystals having a shell of ZnS and a core of InP, and oleylamine supported thereon.
(Example 2)
An ink was prepared in the same manner as in Example 1 except that the compound represented by ET-1 was changed to the compound represented by ET-2.
 (実施例3)
 上記ET-1で示される化合物を上記ET-3(Lumtec社製)で示される化合物に変更したこと以外は、前記実施例1と同様にして、インクを調製した。
 (実施例4)
 上記ET-1で示される化合物を上記ET-4(Lumtec社製)で示される化合物に変更したこと以外は、前記実施例1と同様にして、インクを調製した。
 (実施例5)
 上記ET-1で示される化合物を上記ET-5で示される化合物に変更したこと以外は、前記実施例1と同様にして、インクを調製した。
(Example 3)
An ink was prepared in the same manner as in Example 1 except that the compound represented by ET-1 was changed to the compound represented by ET-3 (manufactured by Lumtec).
(Example 4)
An ink was prepared in the same manner as in Example 1 except that the compound represented by ET-1 was changed to the compound represented by ET-4 (manufactured by Lumtec).
(Example 5)
An ink was prepared in the same manner as in Example 1 except that the compound represented by ET-1 was changed to the compound represented by ET-5.
 (比較例1)
 上記ET-1で示される化合物を下記で示されるビフェニル誘導体に変更したこと以外は、前記実施例1と同様にして、インクを調製した。
(Comparative example 1)
An ink was prepared in the same manner as in Example 1 except that the compound represented by ET-1 was changed to a biphenyl derivative shown below.
Figure JPOXMLDOC01-appb-C000014
Figure JPOXMLDOC01-appb-C000014
 3.発光効率の評価
 洗浄したITO基板にUV/Oを照射し、スピンコートによりポリ(3,4-エチレンジオキシチオフェン)-ポリ(スチレンスルホン酸)(PEDOT-PSS)を45nm成膜し、大気中で180℃、15分間加熱し、正孔注入層を形成した。次いで、TFBの0.6重量%キシレン溶液を、正孔注入層上にスピンコートにより20nm成膜し、窒素雰囲気下にて200℃で30分間乾燥させることで、正孔輸送層を形成した。次に、前記粒子および電荷輸送材料を含有するインクを、正孔輸送層上にスピンコートにより30nm成膜し、窒素雰囲気下にて110℃で15分間乾燥させることで、発光層を形成した。
3. Evaluation of luminous efficiency UV / O 3 was irradiated to the cleaned ITO substrate, and 45 nm of poly (3,4-ethylenedioxythiophene) -poly (styrene sulfonic acid) (PEDOT-PSS) was formed by spin coating, The resultant was heated at 180 ° C. for 15 minutes to form a hole injection layer. Next, a 0.6 wt% xylene solution of TFB was spin-coated on the hole injection layer to form a film of 20 nm, and dried at 200 ° C. for 30 minutes in a nitrogen atmosphere to form a hole transport layer. Next, an ink containing the particles and the charge transport material was formed into a film of 30 nm by spin coating on the hole transport layer, and dried at 110 ° C. for 15 minutes in a nitrogen atmosphere to form a light emitting layer.
 次に、発光層まで形成されたITO基板を真空蒸着機に搬送し、40nmの電子輸送層と、0.5nmの電子注入層と、100nmの陰極とを蒸着により順次形成した。
 なお、電子輸送層は、TPBIを、電子注入層は、フッ化リチウムを、陰極は、アルミニウムをそれぞれ用いて形成した。
 さらに、陰極まで形成されたITO基板をグローブボックスに搬送し、エポキシ樹脂を塗布した封止ガラスをITO基板に貼りあわせた。これにより、発光素子を作製した。
Next, the ITO substrate formed up to the light emitting layer was transported to a vacuum deposition machine, and an electron transport layer of 40 nm, an electron injection layer of 0.5 nm, and a cathode of 100 nm were sequentially formed by vapor deposition.
Note that the electron transporting layer was formed using TPBI, the electron injecting layer was formed using lithium fluoride, and the cathode was formed using aluminum.
Furthermore, the ITO substrate formed up to the cathode was transported to a glove box, and the sealing glass coated with an epoxy resin was bonded to the ITO substrate. Thus, a light emitting element was manufactured.
 得られた発光素子に対して、10mA/cmの電流を印加して発光させた際の輝度を輝度計((株)トプコン BM-9)にて測定した。比較例1で得られた発光素子の輝度を100%とし、各実施例で得られた発光素子の輝度を相対値として求めた。
 この評価結果を表1に示す。
The luminance when light was emitted by applying a current of 10 mA / cm 2 to the obtained light emitting element was measured with a luminance meter (Topcon BM-9, Inc.). The luminance of the light emitting device obtained in Comparative Example 1 was 100%, and the luminance of the light emitting device obtained in each Example was determined as a relative value.
The evaluation results are shown in Table 1.
Figure JPOXMLDOC01-appb-T000015
Figure JPOXMLDOC01-appb-T000015
 表1に示すように、各実施例で得られた発光素子は、発光効率に優れていた。また、カルバゾール構造を有する電荷輸送材料を含有するインクを用いて形成された発光層を備える発光素子は、発光効率が向上する傾向にあった。
 これに対して、比較例1で得られた発光素子は、発光効率に劣る結果であった。
As shown in Table 1, the light emitting device obtained in each example was excellent in luminous efficiency. In addition, a light emitting element provided with a light emitting layer formed using an ink containing a charge transport material having a carbazole structure tends to improve the light emission efficiency.
On the other hand, the light emitting element obtained in Comparative Example 1 was a result of being inferior in luminous efficiency.
 本発明は、発光性を有する半導体ナノ結晶と、該半導体ナノ結晶を分散する分散媒と、特定一般式で示される電荷輸送材料とを含有することを特徴とするインクであるので、発光効率の高い発光層を形成し得るインク、および発光効率の高い発光素子を提供することができる。 The present invention is an ink characterized by containing a semiconductor nanocrystal having a light-emitting property, a dispersion medium for dispersing the semiconductor nanocrystal, and a charge transport material represented by a specific general formula. It is possible to provide an ink capable of forming a high light emitting layer, and a light emitting element with high light emission efficiency.
 1   発光素子
 2   陽極
 3   陰極
 4   正孔注入層
 5   正孔輸送層
 6   発光層
 7   電子輸送層
 8   電子注入層
REFERENCE SIGNS LIST 1 light emitting element 2 anode 3 cathode 4 hole injection layer 5 hole transport layer 6 light emitting layer 7 electron transport layer 8 electron injection layer

Claims (4)

  1.  発光性を有する半導体ナノ結晶と、
     該半導体ナノ結晶を分散する分散媒と、
     下記一般式で示される電荷輸送材料とを含有することを特徴とするインク。
    Figure JPOXMLDOC01-appb-C000001
    [式中、Xは、窒素原子またはCRを表し、R~Rは、それぞれ独立して水素原子、アルキル基、アルコキシ基、アリール基、ヘテロアリール基、アリールオキシ基、ヘテロアリールオキシ基のうちの少なくとも1つを含む基を表し、R~Rは、それぞれ独立して、それが結合するベンゼン環とともに環構造を形成してもよく、l、mおよびnは、それぞれ独立して0~5の整数を表し、oは、0~3の整数を表す。]
    Semiconductor nanocrystals having light emitting properties;
    A dispersion medium for dispersing the semiconductor nanocrystals;
    An ink comprising: a charge transport material represented by the following general formula:
    Figure JPOXMLDOC01-appb-C000001
    [Wherein, X represents a nitrogen atom or CR 5 , and R 1 to R 5 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group R 1 to R 3 each independently may form a ring structure with the benzene ring to which it is attached, and l, m and n each independently represent Is an integer of 0 to 5, and o is an integer of 0 to 3. ]
  2.  R~Rのうちの少なくとも1つは、カルバゾール構造を含むか、またはそれが結合するベンゼン環とともにカルバゾール構造を形成している請求項1に記載のインク。 The ink according to claim 1, wherein at least one of R 1 to R 3 contains a carbazole structure or forms a carbazole structure with a benzene ring to which it is attached.
  3.  当該インク中に含まれる前記電荷輸送材料の量は、0.1~50質量%である請求項1または2に記載のインク。 The ink according to claim 1, wherein the amount of the charge transport material contained in the ink is 0.1 to 50% by mass.
  4.  一対の電極と、
     該一対の電極間に設けられた発光層と、
     該発光層と、前記一対の電極の少なくとも一方の電極との間に設けられた電荷輸送層とを備え、
     前記発光層は、発光性を有する半導体ナノ結晶と、下記一般式で示される電荷輸送材料とを含有することを特徴とする発光素子。
    Figure JPOXMLDOC01-appb-C000002
    [式中、Xは、窒素原子またはCRを表し、R~Rは、それぞれ独立して水素原子、アルキル基、アルコキシ基、アリール基、ヘテロアリール基、アリールオキシ基、ヘテロアリールオキシ基のうちの少なくとも1つを含む基を表し、R~Rは、それぞれ独立して、それが結合するベンゼン環とともに環構造を形成してもよく、l、mおよびnは、それぞれ独立して0~5の整数を表し、oは、0~3の整数を表す。]
    A pair of electrodes,
    A light emitting layer provided between the pair of electrodes;
    And a charge transport layer provided between the light emitting layer and at least one of the pair of electrodes.
    A light emitting device characterized in that the light emitting layer contains a semiconductor nanocrystal having a light emitting property and a charge transporting material represented by the following general formula.
    Figure JPOXMLDOC01-appb-C000002
    [Wherein, X represents a nitrogen atom or CR 5 , and R 1 to R 5 each independently represent a hydrogen atom, an alkyl group, an alkoxy group, an aryl group, a heteroaryl group, an aryloxy group, a heteroaryloxy group R 1 to R 3 each independently may form a ring structure with the benzene ring to which it is attached, and l, m and n each independently represent Is an integer of 0 to 5, and o is an integer of 0 to 3. ]
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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7514156B2 (en) 2019-12-11 2024-07-10 日本放送協会 Quantum dot light emitting device and display device

Families Citing this family (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024084570A1 (en) * 2022-10-18 2024-04-25 シャープディスプレイテクノロジー株式会社 Light-emitting element and display device

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013531883A (en) * 2010-05-27 2013-08-08 メルク パテント ゲーエムベーハー Composition comprising quantum dots
WO2013157495A1 (en) * 2012-04-20 2013-10-24 コニカミノルタ株式会社 Organic electroluminescence element and production method for organic electroluminescence element
JP2013543628A (en) * 2010-07-26 2013-12-05 メルク パテント ゲーエムベーハー Nanocrystals in devices
JP2014077046A (en) * 2012-10-10 2014-05-01 Konica Minolta Inc Ink composition for forming light-emitting layer, method for preparing light-emitting device and electroluminescence device
JP2014078380A (en) * 2012-10-10 2014-05-01 Konica Minolta Inc White electroluminescent device
JP2015092612A (en) * 2010-10-22 2015-05-14 コニカミノルタ株式会社 Organic electroluminescent element
JP2015187942A (en) * 2014-03-26 2015-10-29 日本放送協会 Light emitting element, method for manufacturing light emitting element and display device

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2013531883A (en) * 2010-05-27 2013-08-08 メルク パテント ゲーエムベーハー Composition comprising quantum dots
JP2013543628A (en) * 2010-07-26 2013-12-05 メルク パテント ゲーエムベーハー Nanocrystals in devices
JP2015092612A (en) * 2010-10-22 2015-05-14 コニカミノルタ株式会社 Organic electroluminescent element
WO2013157495A1 (en) * 2012-04-20 2013-10-24 コニカミノルタ株式会社 Organic electroluminescence element and production method for organic electroluminescence element
JP2014077046A (en) * 2012-10-10 2014-05-01 Konica Minolta Inc Ink composition for forming light-emitting layer, method for preparing light-emitting device and electroluminescence device
JP2014078380A (en) * 2012-10-10 2014-05-01 Konica Minolta Inc White electroluminescent device
JP2015187942A (en) * 2014-03-26 2015-10-29 日本放送協会 Light emitting element, method for manufacturing light emitting element and display device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP7514156B2 (en) 2019-12-11 2024-07-10 日本放送協会 Quantum dot light emitting device and display device

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