JP2019219512A - Color conversion composition, color conversion sheet, and light source unit, display and illumination device including the same - Google Patents

Abstract

To achieve both improvement in color reproducibility and durability, particularly to achieve both light emission with high color purity and durability in a color conversion composition to be used for a liquid crystal display or an LED illumination.SOLUTION: A color conversion composition is provided, which converts incident light into light at a longer wavelength than that of the incident light and comprises the following (A), (B) and (C) components. They are: (A) at least one type of an organic light-emitting material containing an ester bond; (B) a binder resin; and (C) a compound having a partial structure represented by general formula (1) and having a molecular weight of 2000 or less. In formula (1), Y represents a single bond or C=O; and a black circle represents a covalent bond to an adjoining atom.SELECTED DRAWING: None

Description

  The present invention relates to a color conversion composition, a color conversion sheet, and a light source unit, a display, and a lighting device including the same.

  The application of the multi-color technology based on the color conversion method to liquid crystal displays, organic EL displays, lighting devices, and the like has been actively studied. The color conversion is to convert light emitted from a light emitter to light having a longer wavelength, for example, to convert blue light to green or red light.

  The composition having the color conversion function (hereinafter, referred to as “color conversion composition”) is formed into a sheet, and is combined with, for example, a blue light source to extract three primary colors of blue, green, and red from the blue light source, that is, white light. Can be taken out. A white light source combining such a blue light source and a sheet having a color conversion function (hereinafter, referred to as a “color conversion sheet”) is defined as a backlight unit, and this backlight unit, a liquid crystal driving portion, and a color filter are combined. Thus, a full-color display can be manufactured. In addition, if there is no liquid crystal driving portion, it can be used as it is as a white light source, and can be applied as a white light source such as LED lighting.

  As a problem of the liquid crystal display using the color conversion method, improvement of color reproducibility can be cited. In order to improve the color reproducibility, it is effective to narrow the half width of each of the blue, green, and red emission spectra of the backlight unit and increase the color purity of each of the blue, green, and red colors.

  As a means for solving this, a technique using quantum dots made of inorganic semiconductor fine particles as a component of a color conversion composition has been proposed (for example, see Patent Document 1).

  In addition, a technique has been proposed in which an organic light emitting material is used as a component of a color conversion composition instead of quantum dots. Examples of techniques using an organic light emitting material as a component of a color conversion composition include those using a coumarin derivative (for example, see Patent Document 2), those using a rhodamine derivative (for example, see Patent Document 3), and pyromethene derivatives. (For example, see Patent Document 4).

  In addition, a technique of adding a light stabilizer to prevent deterioration of an organic light emitting material and improve durability has been disclosed (for example, see Patent Document 5).

JP 2012-22028 A JP 2007-273440 A JP 2001-164245 A JP 2011-241160 A International Publication No. 2011/149028

  In recent years, with high definition such as 4K and 8K, high dynamic range (HDR), and high contrast by local dimming, illuminance required for a backlight unit of a liquid crystal display is increasing, and high durability of a color conversion composition is achieved. In addition, it is necessary that the luminous efficiency of the color conversion composition is high. In the technology using the quantum dots of Patent Document 1, the half widths of the green and red emission spectra are certainly narrow, and the color reproducibility is improved. On the other hand, the quantum dots were weak to heat, moisture and oxygen in the air, and had insufficient durability. In addition, there are also problems such as containing cadmium. In addition, when using an organic light emitting material, existing technology such as addition of a specific light stabilizer alone has an effect of improving durability, but is insufficient as a technology for improving durability at high temperatures. there were. In particular, a color conversion composition using an organic light-emitting material has a problem that durability is significantly deteriorated at a high temperature, and the existing technology has not been able to sufficiently solve this problem.

  The problem to be solved by the present invention is to achieve both improvement in color reproducibility and durability in a color conversion composition used for a liquid crystal display or LED lighting, and in particular, emission of high color purity and durability. It is to balance. In particular, an object of the present invention is to provide a color conversion composition and a color conversion sheet having improved durability at high temperatures.

In order to solve the above-mentioned problems and achieve the object, the present invention is a color conversion composition for converting incident light into light having a longer wavelength than the incident light, and comprises the following (A) and (B) ) And (C) components;
(A) at least one kind of organic light-emitting material containing an ester bond (B) binder resin (C) a compound having a partial structure represented by the general formula (1) and having a molecular weight of 2000 or less

(Y is a single bond or C = O. A black circle indicates a covalent bond to an adjacent atom.)
A color conversion composition comprising:

  Since the color conversion composition of the present invention and the color conversion sheet using the same have both high color purity and durability, it is possible to achieve both color reproducibility and durability.

FIG. 2 is a schematic cross-sectional view illustrating an example of the color conversion sheet of the present invention. FIG. 2 is a schematic cross-sectional view illustrating an example of the color conversion sheet of the present invention. FIG. 2 is a schematic cross-sectional view illustrating an example of the color conversion sheet of the present invention. FIG. 2 is a schematic cross-sectional view illustrating an example of the color conversion sheet of the present invention. FIG. 2 is a schematic cross-sectional view illustrating an example of the color conversion sheet of the present invention. FIG. 2 is a schematic cross-sectional view illustrating an example of the color conversion sheet of the present invention. FIG. 2 is a schematic cross-sectional view illustrating an example of the color conversion sheet of the present invention. FIG. 2 is a schematic cross-sectional view illustrating an example of the color conversion sheet of the present invention. 3 shows an absorption spectrum of the compound of Synthesis Example 1. 3 shows an emission spectrum of the compound of Synthesis Example 1.

  Hereinafter, embodiments of the present invention will be specifically described. However, the present invention is not limited to the following embodiments, and can be implemented with various changes depending on purposes and applications.

The color conversion composition according to the embodiment of the present invention is a color conversion composition that converts incident light into light having a longer wavelength than the incident light, and includes the following (A), (B), and (C). )component;
(A) at least one kind of organic light-emitting material containing an ester bond (B) binder resin (C) a compound having a partial structure represented by the general formula (1) and having a molecular weight of 2000 or less

(Y is a single bond or C = O. A black circle indicates a covalent bond to an adjacent atom.)
And a color conversion composition.

<(A) Organic light emitting material>
The color conversion composition according to the embodiment of the present invention contains at least one organic light emitting material. Here, the light-emitting material in the present invention refers to a material that emits light having a wavelength different from that of the light when the light is irradiated. The organic light emitting material is an organic light emitting material.

  In order to achieve high-efficiency color conversion, it is preferable that the light-emitting material is a material exhibiting high emission quantum yield and emission characteristics. In general, the light-emitting material includes known light-emitting materials such as inorganic phosphors, fluorescent pigments, fluorescent dyes, and quantum dots. From the viewpoint of uniformity of dispersion, reduction of the amount of use, and reduction of environmental load, organic light-emitting materials are used. Materials are preferred.

  Examples of the organic light emitting material include the following. For example, a compound having a condensed aryl ring such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, or indene, or a derivative thereof may be mentioned as a suitable organic light emitting material. Further, furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9′-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyridine, pyrazine, naphthyridine, quinoxaline, Suitable organic light-emitting materials include compounds having a heteroaryl ring such as pyrrolopyridine, derivatives thereof, and borane derivatives.

  Also, 1,4-distyrylbenzene, 4,4′-bis (2- (4-diphenylaminophenyl) ethenyl) biphenyl, 4,4′-bis (N- (stilben-4-yl) -N-phenyl Suitable organic light emitting materials include stilbene derivatives such as amino) stilbene, aromatic acetylene derivatives, tetraphenylbutadiene derivatives, aldazine derivatives, pyromethene derivatives, and diketopyrrolo [3,4-c] pyrrole derivatives. Further, coumarin derivatives such as coumarin 6, coumarin 7, coumarin 153, azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole and triazole and metal complexes thereof, cyanine compounds such as indocyanine green, fluorescein, Xanthene-based compounds such as eosin and rhodamine, thioxanthene-based compounds, and the like are mentioned as suitable organic light-emitting materials.

  Also, polyphenylene compounds, naphthalimide derivatives, phthalocyanine derivatives and metal complexes thereof, porphyrin derivatives and metal complexes thereof, oxazine compounds such as Nile Red and Nile Blue, helicene compounds, N, N′-diphenyl-N, N ′ Aromatic amine derivatives such as -di (3-methylphenyl) -4,4'-diphenyl-1,1'-diamine and the like are mentioned as suitable organic light emitting materials. In addition, organic metal complex compounds such as iridium (Ir), ruthenium (Ru), rhodium (Rh), palladium (Pd), platinum (Pt), osmium (Os), and rhenium (Re) are suitable for organic light emission. As a material. However, the organic light emitting material in the present invention is not limited to the above.

  The organic light emitting material used in the present invention contains an ester bond. Since an ester bond can be easily formed by dehydration condensation of a carboxylic acid and an alcohol, it is very useful when modifying an organic molecule. In particular, in the case of an organic light emitting material, aggregation of molecules can be prevented by introducing a bulky substituent, and as a result, the luminous efficiency and durability of the organic light emitting material are further improved. Furthermore, when an ester group is introduced into the central skeleton of the organic light emitting material, the ester group acts as an electron withdrawing group, lowering the electron density of the central skeleton and improving the stability of the organic light emitting material to oxygen. As a result, the durability of the organic light emitting material can be further improved.

  The organic light emitting material may be a fluorescent light emitting material or a phosphorescent light emitting material, but a fluorescent light emitting material is preferable in order to achieve high color purity. Among these, compounds having a condensed aryl ring and derivatives thereof are preferable because of high thermal stability and high light stability.

  As the organic light emitting material, a compound having a coordination bond is preferable from the viewpoint of solubility and diversity of molecular structure. A boron-containing compound such as a boron fluoride complex is also preferable in that the half width is small and light emission with high efficiency is possible.

  Among these compounds, a pyrromethene derivative can be suitably used in that a high fluorescence quantum yield is provided and durability is good. More preferably, it is a compound represented by the general formula (2).

X is C—R ⁷ or N. R ^{1 to} R ⁹ may be the same or different and each may be hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, or an aryl group. Ether, arylthioether, aryl, heteroaryl, halogen, cyano, aldehyde, carbonyl, carboxyl, ester, carbamoyl, amino, nitro, silyl, siloxanyl, boryl, sulfo Group, a phosphine oxide group, or a condensed ring or an aliphatic ring formed between adjacent groups.

  In all of the above groups, hydrogen may be deuterium. The same applies to the compounds described below and their partial structures. Further, in the following description, for example, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms has 6 to 40 carbon atoms including the number of carbon atoms included in the substituent substituted with the aryl group. An aryl group. The same applies to other substituents defining the number of carbon atoms.

  In all of the above groups, when substituted, the substituent includes an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, and an alkylthio group. , Aryl ether group, aryl thioether group, aryl group, heteroaryl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, boryl group , A sulfo group, and a phosphine oxide group are preferable, and specific substituents which are preferable in the description of each substituent are preferable. Further, these substituents may be further substituted by the above-mentioned substituents.

  “Unsubstituted” in the case of “substituted or unsubstituted” means that a hydrogen atom or a deuterium atom has been substituted. The same applies to the case of “substituted or unsubstituted” in the compounds described below or their partial structures.

  Among all the above groups, the alkyl group means, for example, a saturated aliphatic hydrocarbon such as a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, and a tert-butyl group. Represents a group, which may or may not have a substituent. The additional substituent in the case of being substituted is not particularly limited, and examples thereof include an alkyl group, a halogen, an aryl group, and a heteroaryl group. This point is also common to the following description. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably in the range of 1 to 20 and more preferably 1 to 8 in view of availability and cost.

  The cycloalkyl group means, for example, a saturated alicyclic hydrocarbon group such as a cyclopropyl group, a cyclohexyl group, a norbornyl group, and an adamantyl group, which may or may not have a substituent. . The number of carbon atoms in the alkyl group is not particularly limited, but is preferably in the range of 3 or more and 20 or less.

  The heterocyclic group refers to, for example, an aliphatic ring having a non-carbon atom such as a pyran ring, a piperidine ring, or a cyclic amide in the ring, which may or may not have a substituent. Good. The carbon number of the heterocyclic group is not particularly limited, but is preferably in the range of 2 or more and 20 or less.

  The alkenyl group refers to, for example, an unsaturated aliphatic hydrocarbon group containing a double bond such as a vinyl group, an allyl group, and a butadienyl group, which may or may not have a substituent. . The number of carbon atoms of the alkenyl group is not particularly limited, but is preferably in the range of 2 or more and 20 or less.

  The cycloalkenyl group refers to, for example, an unsaturated alicyclic hydrocarbon group containing a double bond such as a cyclopentenyl group, a cyclopentadienyl group, and a cyclohexenyl group, which may have a substituent. It is not necessary to have.

  The alkynyl group means, for example, an unsaturated aliphatic hydrocarbon group containing a triple bond such as an ethynyl group, which may or may not have a substituent. The number of carbon atoms of the alkynyl group is not particularly limited, but is preferably in the range of 2 or more and 20 or less.

  The alkoxy group refers to, for example, a functional group in which an aliphatic hydrocarbon group is bonded via an ether bond such as a methoxy group, an ethoxy group, and a propoxy group.The aliphatic hydrocarbon group has a substituent. May not be included. The carbon number of the alkoxy group is not particularly limited, but is preferably in the range of 1 or more and 20 or less.

  The alkylthio group is obtained by substituting the oxygen atom of the ether bond of the alkoxy group with a sulfur atom. The hydrocarbon group of the alkylthio group may or may not have a substituent. Although the carbon number of the alkylthio group is not particularly limited, it is preferably in the range of 1 to 20.

  An aryl ether group refers to, for example, a functional group in which an aromatic hydrocarbon group is bonded via an ether bond, such as a phenoxy group, and the aromatic hydrocarbon group may or may not have a substituent. Is also good. The carbon number of the aryl ether group is not particularly limited, but is preferably in the range of 6 or more and 40 or less.

  The arylthioether group is a group in which an oxygen atom of an ether bond of the arylether group is substituted with a sulfur atom. The aromatic hydrocarbon group in the arylthioether group may or may not have a substituent. The number of carbon atoms of the arylthioether group is not particularly limited, but is preferably in the range of 6 or more and 40 or less.

  The aryl group includes, for example, phenyl, biphenyl, terphenyl, naphthyl, fluorenyl, benzofluorenyl, dibenzofluorenyl, phenanthryl, anthracenyl, benzophenanthryl, benzoanthracene And an aromatic hydrocarbon group such as a phenyl group, a chrysenyl group, a pyrenyl group, a fluoranthenyl group, a triphenylenyl group, a benzofluoranthenyl group, a dibenzoanthracenyl group, a perylenyl group, and a helicenyl group. Among them, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, an anthracenyl group, a pyrenyl group, a fluoranthenyl group, and a triphenylenyl group are preferred. The aryl group may or may not have a substituent. The carbon number of the aryl group is not particularly limited, but is preferably in the range of 6 or more and 40 or less, more preferably in the range of 6 or more and 30 or less.

When R ^{1 to} R ⁹ are a substituted or unsubstituted aryl group, the aryl group is preferably a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, or an anthracenyl group, and a phenyl group, a biphenyl group Groups, terphenyl groups and naphthyl groups are more preferred. More preferred are a phenyl group, a biphenyl group and a terphenyl group, and a phenyl group is particularly preferred.

  When each substituent is further substituted with an aryl group, the aryl group is preferably a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, an anthracenyl group, and a phenyl group, a biphenyl group, A phenyl group and a naphthyl group are more preferred. Particularly preferred is a phenyl group.

  Heteroaryl group, for example, pyridyl group, furanyl group, thienyl group, quinolinyl group, isoquinolinyl group, pyrazinyl group, pyrimidyl group, pyridazinyl group, triazinyl group, naphthyridinyl group, cinnolinyl group, phthalazinyl group, quinoxalinyl group, quinazolinyl group, Benzofuranyl, benzothienyl, indolyl, dibenzofuranyl, dibenzothienyl, carbazolyl, benzocarbazolyl, carbolinyl, indolocarbazolyl, benzofurcarbazolyl, benzothienocarbazolyl Group, dihydroindenocarbazolyl group, benzoquinolinyl group, acridinyl group, dibenzoacridinyl group, benzimidazolyl group, imidazopyridyl group, benzoxazolyl group, benzothiazolyl group, phenanthrolinyl group, etc. Atoms other than hydrogen shows a cyclic aromatic group having a single or a plurality of rings. However, a naphthyridinyl group means any of a 1,5-naphthyridinyl group, a 1,6-naphthyridinyl group, a 1,7-naphthyridinyl group, a 1,8-naphthyridinyl group, a 2,6-naphthyridinyl group, and a 2,7-naphthyridinyl group. Indicates The heteroaryl group may or may not have a substituent. Although the carbon number of the heteroaryl group is not particularly limited, it is preferably in the range of 2 or more and 40 or less, more preferably 2 or more and 30 or less.

When R ^{1 to} R ⁹ are a substituted or unsubstituted heteroaryl group, examples of the heteroaryl group include pyridyl, furanyl, thienyl, quinolinyl, pyrimidyl, triazinyl, benzofuranyl, benzothienyl, and indolyl. Group, dibenzofuranyl group, dibenzothienyl group, carbazolyl group, benzimidazolyl group, imidazopyridyl group, benzoxazolyl group, benzothiazolyl group, phenanthrolinyl group is preferred, and pyridyl group, furanyl group, thienyl group, quinolinyl group is preferred. More preferred. Particularly preferred is a pyridyl group.

  When each substituent is further substituted with a heteroaryl group, examples of the heteroaryl group include pyridyl, furanyl, thienyl, quinolinyl, pyrimidyl, triazinyl, benzofuranyl, benzothienyl, indolyl, and dibenzoyl. A furanyl group, a dibenzothienyl group, a carbazolyl group, a benzimidazolyl group, an imidazopyridyl group, a benzoxazolyl group, a benzothiazolyl group, and a phenanthrolinyl group are preferred, and a pyridyl group, a furanyl group, a thienyl group, and a quinolinyl group are more preferred. Particularly preferred is a pyridyl group.

  Halogen represents an atom selected from fluorine, chlorine, bromine and iodine. The carbonyl group, carboxyl group, ester group, and carbamoyl group may or may not have a substituent. Here, examples of the substituent include an alkyl group, a cycloalkyl group, an aryl group, a heteroaryl group and the like, and these substituents may be further substituted.

  An amino group is a substituted or unsubstituted amino group. Examples of the substituent in the case of substitution include an aryl group, a heteroaryl group, a linear alkyl group, and a branched alkyl group. As the aryl group and the heteroaryl group, a phenyl group, a naphthyl group, a pyridyl group, and a quinolinyl group are preferable. These substituents may be further substituted. The number of carbon atoms is not particularly limited, but preferably ranges from 2 to 50, more preferably from 6 to 40, and particularly preferably from 6 to 30.

  The silyl group is, for example, an alkylsilyl group such as a trimethylsilyl group, a triethylsilyl group, a tert-butyldimethylsilyl group, a propyldimethylsilyl group, a vinyldimethylsilyl group, a phenyldimethylsilyl group, a tert-butyldiphenylsilyl group, And an arylsilyl group such as a phenylsilyl group and a trinaphthylsilyl group. Substituents on silicon may be further substituted. The number of carbon atoms of the silyl group is not particularly limited, but is preferably in the range of 1 to 30.

The siloxanyl group indicates, for example, a silicon compound group via an ether bond such as a trimethylsiloxanyl group. Substituents on silicon may be further substituted. The boryl group is a substituted or unsubstituted boryl group. Examples of the substituent in the case of substitution include an aryl group, a heteroaryl group, a linear alkyl group, a branched alkyl group, an aryl ether group, an alkoxy group, and a hydroxyl group. Among them, an aryl group and an aryl ether group are preferable. Further, the sulfo group is a substituted or unsubstituted sulfo group. Examples of the substituent in the case of substitution include an aryl group, a heteroaryl group, a linear alkyl group, a branched alkyl group, an aryl ether group, and an alkoxy group. Especially, a linear alkyl group and an aryl group are preferable. Further, a phosphine oxide group, a group represented by ^{-P (= O) R 10 R} 11. R ¹⁰ R ¹¹ is selected from the same group as R ^{1 to} R ⁹ .

A condensed ring and an aliphatic ring formed between adjacent substituents are conjugated or non-conjugated when any two adjacent substituents (for example, R ¹ and R ^{2 in} the general formula (2)) are bonded to each other. To form a cyclic skeleton. Such a constitutive element of the condensed ring and the aliphatic ring may include an element selected from nitrogen, oxygen, sulfur, phosphorus, and silicon, in addition to carbon. Further, these condensed ring and aliphatic ring may be further condensed with another ring.

The compound represented by the general formula (2) exhibits a high emission quantum yield and a small half-width of the emission spectrum, so that both efficient color conversion and high color purity can be achieved. Further, the compound represented by the general formula (2) has various properties such as luminous efficiency, color purity, thermal stability, light stability and dispersibility by introducing an appropriate substituent at an appropriate position. And physical properties can be adjusted. For example, compared to a case where all of R ¹ , R ³ , R ⁴ and R ⁶ are hydrogen, at least one of R ¹ , R ³ , R ⁴ and R ⁶ is a substituted or unsubstituted alkyl group or a substituted or unsubstituted alkyl group. An aryl group or a substituted or unsubstituted heteroaryl group shows better thermal stability and light stability.

When at least one of R ¹ , R ³ , R ⁴ and R ⁶ is a substituted or unsubstituted alkyl group, examples of the alkyl group include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, An alkyl group having 1 to 6 carbon atoms such as a sec-butyl group, a tert-butyl group, a pentyl group, and a hexyl group is preferred. Further, as the alkyl group, from the viewpoint of excellent thermal stability, methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group, tert-butyl group, cyclohexyl group preferable. In addition, from the viewpoint of preventing concentration quenching and improving the emission quantum yield, the alkyl group is more preferably a sterically bulky tert-butyl group or cyclohexyl group. From the viewpoint of ease of synthesis and availability of raw materials, a methyl group is also preferably used as the alkyl group.

When at least one of R ¹ , R ³ , R ⁴ and R ⁶ is a substituted or unsubstituted aryl group, the aryl group is preferably a phenyl group, a biphenyl group, a terphenyl group, or a naphthyl group, more preferably A phenyl group and a biphenyl group. Particularly preferred is a phenyl group.

When at least one of R ¹ , R ³ , R ⁴ and R ⁶ is a substituted or unsubstituted heteroaryl group, the heteroaryl group is preferably a pyridyl group, a quinolinyl group or a thienyl group, more preferably a pyridyl group. Quinolinyl group. Particularly preferred is a pyridyl group.

All of R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different and are preferably a substituted or unsubstituted alkyl group because of good solubility in a binder resin and a solvent. In this case, the alkyl group is preferably a methyl group from the viewpoints of ease of synthesis and availability of raw materials.

When R ¹ , R ³ , R ⁴ and R ⁶ are all the same or different and are each a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group, better thermal stability and It is preferable because it shows light stability. In this case, all of R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and more preferably a substituted or unsubstituted aryl group.

Some substituents improve multiple properties, but those that exhibit satisfactory performance in all are limited. In particular, it is difficult to achieve both high luminous efficiency and high color purity. Therefore, by introducing a plurality of types of substituents into the compound represented by the general formula (2), it is possible to obtain a compound that is balanced in light emission characteristics, color purity, and the like. For example, by introducing a plurality of types of substituents such as R ¹ ≠ R ⁴ , R ³ ≠ R ⁶ , R ¹ ≠ R ^3, or R ⁴ ≠ R ⁶ , light emission characteristics and color purity are adjusted. be able to. Here, “≠” indicates that the groups have different structures, and R ¹ ≠ R ⁴ indicates that R ¹ and R ⁴ have different structures.

R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and when each is a substituted or unsubstituted aryl group, R ¹ , R ³ , R ⁴ and R ⁶ are the same or different. And it is preferably a substituted or unsubstituted phenyl group. When substituted, the substituent is preferably an alkyl group, an alkoxy group, or an ester group, and these substituents may be further substituted. Among them, a methyl group, a tert-butyl group, a methoxy group, a methyl ester group, and an ethyl ester group are preferable, and these substituents may be further substituted.

In the general formula (2), X is preferably C—R ⁷ from the viewpoint of light stability. When X is C—R ⁷ , the substituent R ⁷ greatly affects the durability of the compound represented by the general formula (2), that is, the decrease over time in the emission intensity of the compound. Specifically, when R ⁷ is hydrogen, the reactivity of this site is high, so that this site easily reacts with moisture or oxygen in the air. This causes decomposition of the compound represented by the general formula (2). Further, when R ⁷ is a substituent having a large degree of freedom of movement of a molecular chain such as an alkyl group, the reactivity certainly decreases, but the compounds aggregate over time in the color conversion sheet, As a result, the emission intensity is reduced due to concentration quenching. Therefore, R ⁷ is preferably a group that is rigid, has a low degree of freedom of movement, and hardly causes aggregation. Specifically, R ⁷ is preferably a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group. Preferably, it is either one.

It is preferable that X is C—R ⁷ and R ⁷ is a substituted or unsubstituted aryl group from the viewpoint of giving a higher fluorescence quantum yield, making it more difficult to thermally decompose, and from the viewpoint of photostability. As the aryl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, and an anthracenyl group are preferable from the viewpoint of not impairing the emission wavelength.

Furthermore, in order to enhance the photostability of the compound represented by the general formula (2), it is necessary to appropriately suppress the twist of the carbon-carbon bond between R ⁷ and the pyromethene skeleton. This is because, if the twist is excessively large, the reactivity to the excitation light is increased, and the light stability is reduced. From such a viewpoint, R ⁷ is preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted naphthyl group, and is preferably a substituted or unsubstituted naphthyl group. Is more preferably a substituted or unsubstituted biphenyl group or a substituted or unsubstituted terphenyl group. Particularly preferred is a substituted or unsubstituted phenyl group.

Further, R ⁷ is preferably a suitably bulky substituent. When R ⁷ has a certain bulkiness, aggregation of molecules can be prevented, and as a result, the luminous efficiency and durability of the compound represented by the general formula (2) are further improved.

A more preferred example of such a bulky substituent includes the structure of R ⁷ represented by the following general formula (3).

  In the general formula (3), r represents hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an arylether group, or an arylthioether. Group, aryl group, heteroaryl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, boryl group, sulfo group, phosphine oxide group Selected from the group consisting of k is an integer of 1 to 3. When k is 2 or more, r may be the same or different.

  From the viewpoint that a higher emission quantum yield can be obtained, r is preferably a substituted or unsubstituted aryl group. Among these aryl groups, a phenyl group and a naphthyl group are particularly preferred. When r is an aryl group, k in the general formula (3) is preferably 1 or 2, and more preferably 2 from the viewpoint of further preventing aggregation of molecules. Further, when k is 2 or more, it is preferable that at least one of r is substituted with an alkyl group. As the alkyl group in this case, a methyl group, an ethyl group, and a tert-butyl group are particularly preferable examples from the viewpoint of thermal stability.

  Further, from the viewpoint of controlling the fluorescence wavelength or the absorption wavelength or increasing the compatibility with the solvent, r is preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group or a halogen. , A methyl group, an ethyl group, a tert-butyl group, and a methoxy group are more preferable. From the viewpoint of dispersibility, a tert-butyl group and a methoxy group are particularly preferred. When r is a tert-butyl group or a methoxy group, it is more effective in preventing quenching due to aggregation between molecules.

In another embodiment of the compound represented by the general formula (2), at least one of R ^{1 to} R ⁷ is preferably an electron-withdrawing group or a group substituted with an electron-withdrawing group. . In particular, (1) at least one of R ^{1 to} R ⁶ is an electron withdrawing group, (2) R ⁷ is substituted with an electron withdrawing group, or (3) R ^{1 to} R ⁶ Preferably, at least one of them is an electron withdrawing group, and R ⁷ is substituted with an electron withdrawing group. As described above, by introducing an electron withdrawing group into the pyrromethene skeleton of the compound, the electron density of the pyrromethene skeleton can be significantly reduced. Thereby, the stability of the compound to oxygen is further improved, and as a result, the durability of the compound can be further improved.

  The electron-withdrawing group is also called an electron-accepting group, and is an atomic group that attracts electrons from a substituted atomic group due to an induction effect or a resonance effect in organic electron theory. Examples of the electron withdrawing group include those having a positive value as a substituent constant (σp (para)) according to the Hammett rule. The substituent constant (σp (para)) of the Hammett's rule can be quoted from Chemical Handbook Basic Edition, Revised 5th Edition (page II-380). Although the phenyl group may have a positive value as described above, the electron-withdrawing group does not include the phenyl group in the present invention.

Examples of the electron withdrawing group include, for example, -F (σp: +0.06), -Cl (σp: +0.23), -Br (σp: +0.23), -I (σp: +0.18), -CO ₂ R ^{12 (σp:} when ^{R 12} is ethyl group _{+0.45), - CONH 2 (σp} : +0.38), - COR 12 (σp: +0.49 when ^{R 12} is a methyl group), - _{CF 3 (σp: +0.50),} - SO 2 R 12 (σp: when ^{R 12} is a methyl group _{+0.69), - NO 2 (σp} : +0.81) , and the like. R ¹² is each independently a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring-forming atoms, Represents a substituted alkyl group having 1 to 30 carbon atoms or a substituted or unsubstituted cycloalkyl group having 1 to 30 carbon atoms. Specific examples of these groups include the same examples as described above.

  Preferred electron withdrawing groups include fluorine, a fluorinated aryl group, a fluorinated heteroaryl group, a fluorinated alkyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted ester group, a substituted or unsubstituted amide group, Examples thereof include a substituted or unsubstituted sulfonyl group or a cyano group. This is because they are not easily chemically decomposed.

  More preferred electron withdrawing groups include a fluorinated alkyl group, a substituted or unsubstituted acyl group, a substituted or unsubstituted ester group, and a cyano group. This is because these lead to the effect of preventing concentration quenching and improving the emission quantum yield. Particularly preferred electron withdrawing groups are substituted or unsubstituted ester groups.

The compound represented by the general formula (2) has a substituted or unsubstituted ester group in at least one of R ^{1 to} R ⁹ . In particular, as described above, at least one of R ^{1 to} R ⁷ is preferably a substituted or unsubstituted ester group, or a group substituted with a substituted or unsubstituted ester group.

Among them, at least one of R ² and R ⁵ may be the same or different, and a substituted or unsubstituted ester group can improve durability without lowering color purity. preferable. In particular, both R ² and R ⁵ may be the same or different, and it is particularly preferable that they are substituted or unsubstituted ester groups from the viewpoint of improving durability.

R ⁸ and R ⁹ are preferably an alkyl group, an aryl group, a heteroaryl group, fluorine, a fluorine-containing alkyl group, a fluorine-containing heteroaryl group or a fluorine-containing aryl group, and a cyano group. In particular, R ⁸ and R ⁹ are more preferably fluorine, a fluorine-containing aryl group, or a cyano group because they are stable to excitation light and can obtain a higher fluorescence quantum yield.

  Here, the fluorine-containing aryl group is an aryl group containing fluorine, and examples thereof include a fluorophenyl group, a trifluoromethylphenyl group, and a pentafluorophenyl group. The fluorine-containing heteroaryl group is a heteroaryl group containing fluorine, and examples thereof include a fluoropyridyl group, a trifluoromethylpyridyl group, and a trifluoropyridyl group. The fluorine-containing alkyl group is an alkyl group containing fluorine, and examples thereof include a trifluoromethyl group and a pentafluoroethyl group.

By lowering the electron density on the boron atom, stability is improved with respect to oxygen of the compound represented by the general formula (1), as a result, it is possible to further improve the durability of the above compounds, R ⁸ and More preferably, R ⁹ is each independently a fluorine or cyano group.

When at least one of R ⁸ and R ⁹ is a cyano group, the electron density on the boron atom is further reduced, and it is particularly preferable when both R ⁸ and R ⁹ are a cyano group. On the other hand, from the viewpoint that a high fluorescence quantum yield can be obtained, R ⁸ and R ⁹ are also preferably fluorine. It is more preferable that both R ⁸ and R ⁹ are fluorine from the viewpoint of ease of synthesis.

As one of preferred examples of the compound represented by the general formula (2), R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and each is a substituted or unsubstituted alkyl group. Further, there is a case where X is C—R ⁷ and R ⁷ is a group represented by the general formula (3). In this case, R ⁷ is particularly preferably a group represented by the general formula (3) in which r is contained as a substituted or unsubstituted phenyl group.

Further, as another preferred example of the compound represented by the general formula (2), R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and may be substituted or unsubstituted. A phenyl group, wherein X is C—R ⁷ and R ⁷ is a group represented by the general formula (3). In this case, R ⁷ is more preferably a group represented by the general formula (3) in which r is contained as a tert-butyl group or a methoxy group, and represented by a general formula (3) in which r is contained as a methoxy group. It is particularly preferred that the group is

Further, as another preferred example of the compound represented by the general formula (2), R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and may be substituted or unsubstituted. An alkyl group, and R ² and R ⁵ may be the same or different, each being a substituted or unsubstituted ester group, X is C—R ⁷ , and R ⁷ is a group represented by the general formula: The case represented by (3) is exemplified. In this case, R ⁷ is particularly preferably a group represented by the general formula (3) in which r is contained as a substituted or unsubstituted phenyl group.

Further, as another preferred example of the compound represented by the general formula (2), R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and may be substituted or unsubstituted. A phenyl group, and R ² and R ⁵ may be the same or different, each being a substituted or unsubstituted ester group, X is C—R ⁷ , and R ⁷ is a general formula The case represented by (3) is exemplified. In this case, R ⁷ is more preferably a group represented by the general formula (3) in which r is contained as a tert-butyl group or a methoxy group, and represented by a general formula (3) in which r is contained as a methoxy group. It is particularly preferred that the group is

  Examples of the compound represented by the general formula (2) are shown below, but the compound is not limited thereto.

  The compound represented by the general formula (2) can be synthesized, for example, by the method described in JP-T-8-509471 or JP-A-2000-208262. That is, by reacting a pyromethene compound with a metal salt in the presence of a base, the intended pyrromethene-based metal complex can be obtained.

For the synthesis of a pyrromethene-boron fluoride complex, see J. Mol. Org. Chem. , Vol. 64, No. 21 pp. 7813-7819 (1999), Angew. Chem. , Int. Ed. Engl. , Vol. 36, pp. The compound represented by the general formula (2) can be synthesized with reference to the method described in 1333-1335 (1997) and the like. For example, after heating a compound represented by the following general formula (4) and a compound represented by the general formula (5) in 1,2-dichloroethane in the presence of phosphorus oxychloride, the compound represented by the following general formula (6) A method of reacting the compound represented by 1,2-dichloroethane in the presence of triethylamine to obtain a compound represented by the general formula (2) is mentioned. However, the present invention is not limited to this. Here, R ^{1 to} R ⁹ are the same as described above. J represents a halogen.

  Further, when introducing an aryl group or a heteroaryl group, a method of generating a carbon-carbon bond by using a coupling reaction between a halogenated derivative and a boronic acid or a boronic acid esterified derivative may be mentioned. However, the present invention is not limited to this. Similarly, when introducing an amino group or a carbazolyl group, for example, a method of generating a carbon-nitrogen bond by using a coupling reaction between a halogenated derivative and an amine or a carbazole derivative under a metal catalyst such as palladium is known. However, the present invention is not limited to this.

  The color conversion composition according to the embodiment of the present invention can appropriately contain other compounds as necessary in addition to the compound represented by the general formula (2). For example, an assist dopant such as rubrene may be contained in order to further increase the energy transfer efficiency from the excitation light to the compound represented by the general formula (2). When it is desired to add a luminescent color other than the luminescent color of the compound represented by the general formula (2), a desired organic luminescent material, for example, an organic luminescent material such as a coumarin dye or a rhodamine dye may be added. it can. In addition to these organic light-emitting materials, known light-emitting materials such as inorganic phosphors, fluorescent pigments, fluorescent dyes, and quantum dots can be added in combination.

  Hereinafter, examples of organic light-emitting materials other than the compound represented by the general formula (2) are shown below, but the present invention is not particularly limited thereto.

  The color conversion composition according to the embodiment of the present invention is a light-emitting material which emits light whose peak wavelength is observed in a range of 500 nm to 580 nm by using excitation light having a wavelength of 400 nm to 500 nm (hereinafter, “light-emitting material”). Material (a) ”). Hereinafter, the light emission observed in the region where the peak wavelength is 500 nm or more and 580 nm or less is referred to as “green light emission”.

  Further, the color conversion composition according to the embodiment of the present invention is excited by one or both of the excitation light having a wavelength of 400 nm or more and 500 nm or less and the light emission from the light emitting material (a), thereby obtaining a peak wavelength. Preferably contains a light-emitting material exhibiting light emission observed in a region of 580 nm or more and 750 nm or less (hereinafter, referred to as “light-emitting material (b)”). Hereinafter, the emission observed in the region where the peak wavelength is 580 nm or more and 750 nm or less is referred to as “red emission”.

  In general, as the energy of the excitation light is higher, the material is more likely to be decomposed. However, the excitation light having a wavelength of 400 nm or more and 500 nm or less has a relatively small excitation energy. For this reason, light emission with good color purity can be obtained without decomposing the light emitting material in the color conversion composition.

  In the color conversion composition according to the embodiment of the present invention, either one of the light emitting material (a) and the light emitting material (b) may be included, or both may be included. The light emitting material (a) may be used alone or in combination of two or more. Similarly, the light emitting material (b) may be used alone or in combination of two or more.

  Part of the excitation light having a wavelength of 400 nm or more and 500 nm or less transmits through the color conversion composition according to the embodiment of the present invention, and thus can itself be used as blue light emission. Therefore, the color conversion composition according to the embodiment of the present invention includes a light emitting material (a) emitting green light and a light emitting material (b) emitting red light, and a blue LED having a sharp emission peak as blue light. When used, each of the blue, green, and red colors shows a sharp emission spectrum, and white light with good color purity can be obtained. As a result, particularly in a display, colors can be more vivid and a larger color gamut can be efficiently created. Further, in lighting applications, the emission characteristics of the green and red regions are particularly improved compared to the white LEDs combining a blue LED and a yellow phosphor, which are currently mainstream, so that a preferable white color with improved color rendering properties is provided. A light source can be obtained.

  Examples of the light emitting material (a) include coumarin derivatives such as coumarin 6, coumarin 7, and coumarin 153, cyanine derivatives such as indocyanine green, fluorescein derivatives such as fluorescein, fluorescein isothiocyanate, carboxyfluorescein diacetate, and phthalocyanine derivatives such as phthalocyanine green. , Diisobutyl-4,10-dicyanoperylene-3,9-dicarboxylate, and other perylene derivatives, as well as pyromethene derivatives, stilbene derivatives, oxazine derivatives, naphthalimide derivatives, pyrazine derivatives, benzimidazole derivatives, benzoxazole derivatives, benzothiazole Derivatives, imidazopyridine derivatives, azole derivatives, compounds having a condensed aryl ring such as anthracene and derivatives thereof, aromatic amine derivatives, organic Metal complex compounds, and the like as preferred. However, the light emitting material (a) is not particularly limited to these.

  Among these compounds, the pyrromethene derivative is a particularly suitable compound because it gives a high emission quantum yield and has good durability. As the pyromethene derivative, for example, a compound represented by the following general formula (2) is preferable because it emits light with high color purity.

  Examples of the light-emitting material (b) include cyanine derivatives such as 4-dicyanomethylene-2-methyl-6- (p-dimethylaminostyryl) -4H-pyran, and rhodamines such as rhodamine B, rhodamine 6G, rhodamine 101, and sulfolhodamine 101. Derivatives, pyridine derivatives such as 1-ethyl-2- (4- (p-dimethylaminophenyl) -1,3-butadienyl) -pyridinium-perchlorate, N, N'-bis (2,6-diisopropylphenyl)- Perylene derivatives such as 1,6,7,12-tetraphenoxyperylene-3,4: 9,10-bisdicarbimide, porphyrin derivatives, pyromethene derivatives, oxazine derivatives, pyrazine derivatives, naphthacene and dibenzodiindenoperylene Compounds having fused aryl rings, such as derivatives, derivatives and organometallic complexes Compounds and the like as preferred. However, the luminescent material (b) is not particularly limited to these.

  Among these compounds, the pyrromethene derivative is a particularly suitable compound because it gives a high emission quantum yield and has good durability. As the pyromethene derivative, for example, a compound represented by the following general formula (2) is preferable because it emits light with high color purity.

The content of the component (A) in the color conversion composition according to the embodiment of the present invention includes the molar extinction coefficient of the compound, the emission quantum yield and the absorption intensity at the excitation wavelength, and the thickness and transmittance of the color conversion sheet to be prepared. Usually, it is 1.0 × 10 ⁻⁴ parts by weight to 30 parts by weight based on 100 parts by weight of the component (B). Above all, it is more preferably 1.0 × 10 ⁻³ parts by weight to 10 parts by weight, and particularly preferably 5.0 × 10 ⁻³ parts by weight to 5 parts by weight.

Further, when the color conversion composition contains both the light emitting material (a) emitting green light and the light emitting material (b) emitting red light, part of the green light is converted to red light. since the content of _{w a} of the light-emitting material (a), the content _{w b} of the luminescent material (b) is preferably a relationship of _{w a} ≧ _{w b.} The ratio between the content w _b and content w _a is, w _a: w _b = 1000: 1 to 1: 1, 500: 1 to 2: and more preferably 1, 200: 1 A ratio of 3: 1 is particularly preferred. However, the content of w _a and the content w _b are weight percent relative to the weight of the component (B).

<(B) Binder resin>
In the color conversion composition according to the embodiment of the present invention, as the binder resin, a material having excellent moldability, transparency, heat resistance and the like is suitably used. Examples of the binder resin include, for example, a photocurable resist material having a reactive vinyl group such as an acrylic acid type, a methacrylic acid type, a polyvinyl cinnamate type, a ring rubber type, an epoxy resin, a silicone resin (silicone rubber, silicone rubber). Organopolysiloxane cured products (including crosslinked products) such as gels), urea resins, fluorine resins, polycarbonate resins, acrylic resins, urethane resins, melamine resins, polyvinyl resins, polyamide resins, phenol resins, polyvinyl alcohol resins, polyvinyl butyral resins And known resins such as cellulose resin, aliphatic ester resin, aromatic ester resin, aliphatic polyolefin resin, and aromatic polyolefin resin. Further, as the binder resin, a mixture or a copolymer of these resins may be used. By appropriately designing these resins, a binder resin useful for the color conversion composition according to the embodiment of the present invention can be obtained.

  Among these resins, an epoxy resin, a silicone resin, an acrylic resin, a polyester resin, or a copolymer or a mixture thereof can be suitably used from the viewpoints of transparency, heat resistance, and the like. Among them, an acrylic resin, a copolymer resin containing an acrylate or methacrylate ester portion, or a polyester resin is preferable because of showing high transparency and excellent dispersibility of the organic light emitting material. Among them, an acrylic resin and a polyester resin consisting only of an acrylate or methacrylate ester portion are preferable in that the concentration quenching is suppressed and sufficient luminance is obtained because the organic light-emitting material is excellent in dispersibility. In addition, a thermosetting resin or a photocurable resin is preferably used because the film forming process is easy.

  The glass transition temperature (Tg) of the binder resin is not particularly limited, but is preferably 30 ° C. or more and 180 ° C. or less. When Tg is lower than 30 ° C., the molecular motion of the binder resin increases due to the heat due to the incident light from the light source or the driving heat of the device, and the dispersion state of the light emitting material changes, thereby lowering the durability. On the other hand, when Tg is higher than 180 ° C., the resin becomes brittle, and the flexibility when formed into a sheet or the like decreases. The Tg of the binder resin is more preferably from 50 ° C to 160 ° C, further preferably from 70 ° C to 150 ° C, and particularly preferably from 90 ° C to 140 ° C.

  The molecular weight of the binder resin is not particularly limited depending on the type of the resin, but is preferably 3,000 or more and 1500,000 or less. When the molecular weight is smaller than 3000, the resin becomes brittle, and the flexibility when formed into a sheet or the like becomes low. Further, when the molecular weight is larger than 1500000, there are problems that the viscosity at the time of molding becomes excessively large and the chemical stability of the resin itself is reduced. The molecular weight of the binder resin is more preferably 5,000 to 1,200,000, further preferably 7,000 to 1,000,000, and particularly preferably 10,000 to 800,000.

<(C) Compound having a partial structure represented by general formula (1) and having a molecular weight of 2000 or less>
Organic light-emitting materials modified using an ester bond have excellent luminous efficiency and durability, but have a problem that durability is deteriorated at high temperatures. The cause is considered to be cleavage of the ester bond of the organic light emitting material. It is presumed that at a high temperature, intramolecular motion of the organic light emitting material is activated, and a relatively weak ester bond is preferentially cleaved by an action such as hydrolysis or peroxidation. When the ester bond of the organic light emitting material is cleaved, the properties obtained by the modification are lost, so that the luminous efficiency and durability are considered to be reduced.

  In the color conversion composition according to the embodiment of the present invention, a compound having a partial structure represented by the general formula (1), which is cleaved instead of an ester bond contained in the organic light emitting material, coexists to allow color reproduction. It is possible to obtain a color conversion composition capable of satisfying both properties and durability.

  Y is a single bond or C = O. Black circles indicate covalent bonds to adjacent atoms.

  When Y is a single bond, the compound having the partial structure represented by the general formula (1) is preferably a cyclic ester compound, since it has an appropriate binding energy.

  When Y is C = O, it is preferable because it is more easily cleaved than when Y is a single bond. Examples of the case where Y is C = O include an acid anhydride. Among them, it is preferable that the compound having the partial structure represented by the general formula (1) is an acid anhydride of an aliphatic hydrocarbon acid or an acid anhydride of an aromatic hydrocarbon acid because it has an appropriate binding energy. . Here, the aliphatic hydrocarbon acid is a hydrocarbon acid derived from an aliphatic hydrocarbon having 1 to 30 carbon atoms, and preferably has 1 to 20 carbon atoms. In addition, the aromatic hydrocarbon acid is a hydrocarbon acid derived from an aromatic hydrocarbon having 1 to 40 carbon atoms, and preferably has 1 to 30 carbon atoms.

  Further, it is preferable to have a plurality of partial structures represented by the general formula (1) in the same molecule. For example, the compound having a partial structure represented by the general formula (1) is preferably an acid dianhydride.

  In the color conversion composition according to the embodiment of the present invention, the molecular weight of the compound (C) is 2,000 or less. When the molecular weight is 2000 or less, the degree of freedom of molecular movement in the composition is increased, and the probability that the partial structure represented by the general formula (1) exists in the vicinity of the light emitting material is improved. The molecular weight of the compound of component (C) is more preferably 1500 or less, and even more preferably 1000 or less. In the case where the sheet is formed into a sheet by drying and curing, the component (C) is preferably contained in the sheet even after the sheet is formed. Therefore, the boiling point of the compound of the component (C) is 160 ° C. or more at 1 atm. Preferably, the temperature is 200 ° C. or higher. It is more preferably at least 240 ° C, particularly preferably at least 280 ° C.

  In the color conversion composition according to the embodiment of the present invention, the compound as the component (C) preferably contains neither a nitrogen atom nor a phosphorus atom. When the compound of the component (C) contains a nitrogen atom or a phosphorus atom, electric charges are transferred to and from the organic light emitting material at a high temperature, and the quenching and deterioration of the organic light emitting material are easily caused.

  The compound of the component (C) preferably has a small extinction coefficient in the visible light range so as not to hinder the light from the light source and the light emission of the light emitting material. Specifically, the molar extinction coefficient ε is 200 or less over the entire wavelength range of 400 to 800 nm. ε is preferably as small as possible, and more preferably 150 or less. ε is more preferably 100 or less, and particularly preferably 50 or less. By using a component that absorbs less in the visible light region, the durability of the color conversion composition can be improved without lowering the luminous efficiency.

  Examples of preferred compounds are shown below, but are not limited thereto.

  Each of the above compounds exemplified as the compound of the component (C) may be used alone or in combination of two or more.

In the color conversion composition and the color conversion sheet according to the embodiment of the present invention, the content of the component (C) is 1.0 × 10 ⁻³ parts by weight or more based on 100 parts by weight of the binder resin. Is preferably 1.0 × 10 ⁻² parts by weight or more, and more preferably 1.0 × 10 ⁻¹ parts by weight or more. Further, the content of these additives is preferably 30 parts by weight or less, more preferably 15 parts by weight or less, and more preferably 10 parts by weight or less, based on 100 parts by weight of the binder resin. More preferred.

<Other additives>
The color conversion composition according to the embodiment of the present invention is characterized in that, in addition to the components (A), (B) and (C), a light-fast stabilizer such as an antioxidant, a processing and heat stabilizer, and an ultraviolet absorber. Agents, dispersants and leveling agents for coating film stabilization, plasticizers, crosslinking agents such as epoxy compounds, curing agents such as amines, acid anhydrides and imidazoles, and silane coupling agents as sheet surface modifiers Other additives such as inorganic particles such as silica particles and silicone fine particles and a silane coupling agent can be contained as an adhesion aid and a color conversion material sedimentation inhibitor.

  Examples of the antioxidant include, but are not limited to, phenolic antioxidants. The antioxidants may be used alone or in combination.

  Examples of the processing and heat stabilizers include, but are not limited to, phosphorus-based stabilizers. The stabilizers may be used alone or in combination.

  Examples of the light resistance stabilizer include, for example, benzotriazoles, but are not particularly limited thereto. Further, the light resistance stabilizer may be used alone or in combination of two or more.

  It is preferable that these additives have a small absorption coefficient in the visible region from the viewpoint that they do not inhibit light from a light source or light emission of a light-emitting material. Specifically, the molar extinction coefficient ε of these additives is preferably 200 or less, more preferably 100 or less over the entire wavelength range of 400 nm to 800 nm. It is more preferably at most 80, particularly preferably at most 50.

  Further, as the light-fast stabilizer, a compound having a role as a singlet oxygen quencher can also be suitably used. The singlet oxygen quencher is a material that traps and inactivates singlet oxygen generated by activation of oxygen molecules by light energy. The coexistence of the singlet oxygen quencher in the color conversion sheet can prevent the light emitting material from being deteriorated by singlet oxygen.

  Examples of the compound serving as a singlet oxygen quencher include, but are not limited to, specific tertiary amines and metal salts. Further, these compounds (lightfastness stabilizer) may be used alone or in combination of two or more.

  Further, as the light fastness stabilizer, a compound having a role as a radical quencher can also be suitably used. Especially, a hindered amine compound is mentioned as a suitable example.

In the color conversion composition and the color conversion sheet according to the embodiment of the present invention, the content of these additives is the molar extinction coefficient of the compound, the emission quantum yield and the absorption intensity at the excitation wavelength, and the color conversion sheet to be produced It is preferably 1.0 × 10 ⁻³ parts by weight or more, and more preferably 1.0 × 10 ⁻² parts by weight or more, based on 100 parts by weight of the binder resin, depending on the thickness and transmittance of the binder resin. More preferably, it is still more preferably 1.0 × 10 ^-1 part by weight or more. Further, the content of these additives is preferably 30 parts by weight or less, more preferably 15 parts by weight or less, and more preferably 10 parts by weight or less, based on 100 parts by weight of the binder resin. More preferred.

<Solvent>
The color conversion composition according to the embodiment of the present invention may include a solvent. There is no particular limitation as long as the viscosity of the resin in the fluid state can be adjusted and does not excessively affect the light emission and durability of the light emitting substance. The solvent can be removed by drying. Such solvents include, for example, water, 2-propanol, ethanol, toluene, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, hexane, cyclohexane, tetrahydrofuran, acetone, terpineol, texanol, 1,2-dimethoxyethane, methylcellosolve, ethylcellosolve, butyl carbitol, butyl carbitol acetate, 1-methoxy-2-propanol, propylene glycol monomethyl ether acetate, etc., and a mixture of two or more of these solvents It is also possible to use it. Among these solvents, toluene is particularly preferably used because it does not affect the deterioration of the compound represented by the general formula (2). In addition, methyl ethyl ketone, methyl acetate, ethyl acetate, and tetrahydrofuran are suitably used because the residual solvent after drying is small.

<Production method of color conversion composition>
Hereinafter, an example of a method for producing a color conversion composition according to an embodiment of the present invention will be described. A predetermined amount of materials such as the above-described organic light emitting material, binder resin, and a solvent described below are mixed. After mixing these materials to a predetermined composition, the color conversion layer is homogeneously mixed and dispersed by a homogenizer, a self-revolving type stirrer, a three-roller, a ball mill, a planetary ball mill, a bead mill, etc. A composition for production, ie, a color conversion composition, is produced. It is also preferable to remove bubbles under vacuum or reduced pressure conditions after or during the mixing and dispersion. In addition, a certain component may be mixed in advance, or a process such as aging may be performed. The solvent can be removed by an evaporator to obtain a desired solid content concentration.

<Production method of color conversion sheet>
The configuration of the color conversion sheet according to the embodiment of the present invention is not limited as long as it includes a color conversion layer that is a layer obtained by curing the color conversion composition. As a typical structural example of a color conversion sheet, as shown in FIG. 1, a laminate of a base material layer 10 and a color conversion layer 11 obtained by curing a color conversion composition, or as shown in FIG. As described above, a laminate in which the color conversion layer 11 is sandwiched between a plurality of base layers 10 is exemplified. The color conversion sheet 1 may be further provided with a barrier layer 12 as shown in FIG. 3 in order to prevent the color conversion layer from being deteriorated by oxygen, moisture or heat.

  Further, the color conversion sheet according to the embodiment of the present invention can include two or more color conversion layers. For example, as shown in FIG. 4, a laminate of the base material layer 10 and the color conversion layer 11A and the color conversion layer 11B, or as shown in FIG. A laminate sandwiched between the base layers 10 and a laminate in which the transparent intermediate layer 13 is provided between the color conversion layers 11A and 11B as shown in FIG. Further, a configuration in which the same color conversion layer is continuous, such as a color conversion layer 11A / 11A / 11B, a color conversion layer 11A / 11B / 11B, or a color conversion layer 11A / 11A / 11B / 11B, may also be used.

  Note that these are merely examples, and the specific configuration of the color conversion sheet according to the embodiment of the present invention is not limited thereto, and a configuration obtained by appropriately changing the matters derived from the following description is also within the scope of the present invention. included.

(Color conversion layer)
Next, an example of a method for manufacturing a color conversion layer of the color conversion sheet according to the embodiment of the present invention will be described. The color conversion composition prepared by the above-described method is applied to the underlayer such as a base material layer and a barrier layer, and dried. Coating: reverse roll coater, blade coater, slit die coater, direct gravure coater, offset gravure coater, kiss coater, natural roll coater, air knife coater, roll blade coater, reverse roll blade coater, two stream coater, rod coater, wire bar It can be performed by a coater, an applicator, a dip coater, a curtain coater, a spin coater, a knife coater or the like. In order to obtain the uniformity of the film thickness of the color conversion layer, it is preferable to apply by a slit die coater.

  Drying of the color conversion layer can be performed using a general heating device such as a hot air dryer or an infrared dryer. For heating the color conversion sheet, a general heating device such as a hot air dryer or an infrared dryer is used. In this case, the heating condition is usually 40 ° C. to 250 ° C. for 1 minute to 5 hours, preferably 60 ° C. to 200 ° C. for 2 minutes to 4 hours. It is also possible to heat and cure stepwise such as step cure.

  After producing the color conversion layer, the base material layer can be changed as necessary. In this case, as a simple method, for example, a method of performing replacement using a hot plate, a method using a vacuum laminator or a dry film laminator, and the like are exemplified, but are not limited thereto.

  When the color conversion sheet according to the embodiment of the present invention includes two or more color conversion layers, a known method such as coating or dry lamination can be used as a method for laminating each layer. In the present invention, the method of laminating each layer is not particularly limited. For example, when two color conversion layers, ie, the (L1) layer and the (L2) layer are laminated, the (L2) layer is coated and dried on the (L1) layer A method of forming the (L1) layer on the (L2) layer by coating and drying, a method of laminating a separately formed (L2) layer self-supporting film on the (L1) layer, and a method of (L2). ) A method of laminating a self-supporting film (L1) layer separately formed on a layer, a laminated unit having a laminated structure of “base layer / (L1) layer” and a laminated structure of “(L2) layer / base layer” For example, a method of bonding individually produced laminated units, such as laminating the laminated units described above, may be used. In order to enhance the stability of the color conversion sheet, it is preferable to further perform a heat curing step, a light curing step, an aging step, and the like after laminating the respective layers.

  The thickness of the color conversion layer is not particularly limited, but is preferably 1 μm to 1000 μm, and more preferably 10 μm to 1000 μm. When the thickness of the color conversion layer is smaller than 1 μm, there is a problem that the toughness of the color conversion sheet is reduced. If the thickness of the color conversion layer exceeds 1000 μm, cracks are likely to occur, and it is difficult to form a color conversion sheet. The thickness of the color conversion layer is more preferably 5 μm to 100 μm, further preferably 10 μm to 100 μm, and particularly preferably 15 μm to 100 μm.

  The film thickness (layer thickness) in the present invention is a film thickness (average film thickness) measured based on a method A for measuring thickness by mechanical scanning in a plastic-film and sheet-thickness measuring method in JIS K7130 (1999). Thickness).

(Base material layer)
The base layer is not particularly limited, and may be a known metal, film, glass, ceramic, paper, or the like. Specifically, as a base material layer, a metal plate or foil of aluminum (including an aluminum alloy), zinc, copper, iron, etc., cellulose acetate, PET, polyethylene, polyester, polyamide, polyimide, polyphenylene sulfide, polystyrene, polypropylene, Polycarbonate, polyvinyl acetal, aramid, silicone, polyolefin, thermoplastic fluororesin, plastic film such as copolymer of tetrafluoroethylene and ethylene (ETFE), α-polyolefin resin, polycaprolactone resin, acrylic resin, silicone resin and A plastic film made of a copolymer resin of these and ethylene, paper laminated with the plastic, or paper coated with the plastic, Or deposited paper, the metals is a plastic film or the like which is laminated or deposited. When the base material layer is a metal plate, the surface thereof may be subjected to a chromium-based or nickel-based plating treatment or a ceramic treatment.

  Among these, glass and a resin film are preferably used from the viewpoint of easy production of the color conversion sheet and easy formation of the color conversion sheet. Further, a film having high strength is preferable so that there is no possibility of breakage or the like when handling the film-like base layer. Resin films are preferred in terms of their required properties and economy, and among these, plastic films selected from the group consisting of PET, polyphenylene sulfide, polycarbonate, and polypropylene are preferred in terms of economy and handleability. When the color conversion sheet is dried or when the color conversion sheet is pressed and formed at a high temperature of 200 ° C. or more by an extruder, a polyimide film is preferable in terms of heat resistance. The surface of the base material layer may be subjected to a release treatment in advance from the viewpoint of easy peeling of the sheet. Similarly, the surface of the base material layer may be previously subjected to an easy adhesion treatment in order to improve the adhesion between the layers.

  The thickness of the base material layer is not particularly limited, but the lower limit is preferably 12 μm or more, and more preferably 38 μm or more. The upper limit is preferably 5000 μm or less, more preferably 3000 μm or less.

(Barrier layer)
The color conversion sheet according to the embodiment of the present invention may further have a barrier layer. The barrier layer is appropriately used to prevent the color conversion layer from being deteriorated by oxygen, moisture, or heat. As this barrier layer, for example, silicon oxide, aluminum oxide, titanium oxide, tantalum oxide, zinc oxide, tin oxide, indium oxide, yttrium oxide, inorganic oxides such as magnesium oxide, silicon nitride, aluminum nitride, titanium nitride, Inorganic nitride such as silicon carbonitride, or a mixture thereof, or a metal oxide thin film or a metal nitride thin film obtained by adding other elements thereto, or a polyvinyl chloride resin, an acrylic resin, a silicon resin, or a melamine resin Examples include films made of various resins such as resins, urethane resins, fluorine resins, and polyvinyl alcohol resins such as saponified vinyl acetate.

  Examples of the barrier resin suitably used for the barrier layer in the present invention include resins such as polyester, polyvinyl chloride, nylon, polyvinyl fluoride, polyvinylidene chloride, polyacrylonitrile, polyvinyl alcohol, and ethylene-vinyl alcohol copolymer. And mixtures of these resins. Among them, polyvinylidene chloride, polyacrylonitrile, ethylene-vinyl alcohol copolymer, and polyvinyl alcohol have very low oxygen permeability coefficients, and therefore, the barrier resin preferably contains these resins. Further, the barrier resin more preferably contains polyvinylidene chloride, polyvinyl alcohol, and an ethylene-vinyl alcohol copolymer because of its difficulty in discoloration. It is particularly preferred to include coalescence. These resins may be used alone or as a mixture with different resins, but a film made of a single resin is more preferable from the viewpoint of film uniformity and cost.

  As the polyvinyl alcohol, for example, a saponified polyvinyl acetate in which an acetyl group is saponified by 98 mol% or more can be used. Further, as the ethylene-vinyl alcohol copolymer, for example, a saponified ethylene-vinyl acetate copolymer having an ethylene content of 20% to 50% and having an acetyl group of 98 mol% or more can be used.

  Further, as the barrier layer, a commercially available resin or film can be used. Specific examples include polyvinyl alcohol resin PVA117 manufactured by Kuraray Co., Ltd., and ethylene-vinyl alcohol copolymer (“EVAL” (registered trademark)) resins L171B and F171B manufactured by Kuraray Co., Ltd., and film EF-XL.

  The barrier layer may include an antioxidant, a curing agent, a cross-linking agent, a processing and heat stabilizer, an ultraviolet absorber, etc., as necessary, within a range that does not excessively affect the light emission and durability of the color conversion layer. A light stability stabilizer or the like may be added.

  The thickness of the barrier layer is not particularly limited, but is preferably 100 μm or less from the viewpoint of flexibility and cost of the entire color conversion sheet. It is more preferably 50 μm or less, and further preferably 20 μm or less. Particularly preferably, it is 10 μm or less, and may be 1 μm or less. However, from the viewpoint of ease of layer formation, the thickness of the barrier layer is preferably 0.01 μm or more.

  In the present invention, the barrier layer may be provided on each end face on both sides in the stacking direction of the color conversion layer 11 like the barrier layer 12 illustrated in FIG. 3 or may be provided on one end face on both sides in the stacking direction. Good. When two or more color conversion layers are included, they may be provided on both sides of the color conversion layer 11A and the color conversion layer 11B as in the barrier layer 12 illustrated in FIG. 7, or may be provided on only one side. Is also good. Further, as in the barrier layer 12 illustrated in FIG. 8, it may be provided on both sides of the color conversion layer 11A and both sides of the color conversion layer 11B.

(Other functional layers)
The color conversion sheet according to the embodiment of the present invention has a light diffusion layer, an anti-reflection function, an anti-glare function, an anti-reflection and anti-glare function, a hard coat function (abrasion resistance function), An auxiliary layer having a prevention function, an antifouling function, an electromagnetic wave shielding function, an infrared cut function, an ultraviolet cut function, a polarization function, and a toning function may be further provided.

(Adhesive layer)
In the color conversion sheet according to the embodiment of the present invention, an adhesive layer may be provided between the respective layers as needed. The adhesive layer is not particularly limited as long as it does not excessively affect the light emission and durability of the color conversion sheet, and a known material can be used. For example, when strong adhesion is required, a photocurable material, a thermosetting material, an anaerobic curable material, or a thermoplastic material can be preferably used as the adhesive layer. Among them, a thermosetting material is more preferable, and a thermosetting material that can be hardened at 0 ° C to 150 ° C is particularly preferable.

  The thickness of the adhesive layer is not particularly limited, but is preferably 0.01 μm to 100 μm, and more preferably 0.01 μm to 25 μm. More preferably, it is 0.05 μm to 5 μm, particularly preferably 0.05 μm to 1 μm.

<Excitation light>
Any kind of excitation light can be used as long as it emits light in a wavelength region that can be absorbed by the organic light emitting material used in the present invention. For example, excitation light from any light source such as a fluorescent light source such as a hot cathode tube, a cold cathode tube, an inorganic electroluminescence (EL) device, an organic EL device light source, an LED light source, an incandescent light source, or sunlight can be used. is there. Above all, excitation light from an LED light source is preferable. In displays and lighting applications, excitation light from a blue LED light source having excitation light in a wavelength range of 400 nm or more and 500 nm or less is more preferable because the color purity of blue light can be increased.

  The maximum emission wavelength of the excitation light is more preferably 430 nm or more and 500 nm or less, because the excitation energy is further reduced and deterioration of the organic light emitting material can be suppressed, and further preferably 440 nm or more and 500 nm or less. Particularly preferably, it is 450 nm or more and 500 nm or less. Further, the maximum emission wavelength of the excitation light is more preferably 480 nm or less because the overlap of the emission spectra of the excitation light and the green light can be reduced and color reproducibility can be improved. Is more preferable.

  The excitation light may have one type of emission peak or two or more types of emission peaks, but preferably has one type of emission peak in order to increase color purity. Further, a plurality of excitation light sources having different types of emission peaks can be arbitrarily combined and used.

<Light source unit>
A light source unit according to an embodiment of the present invention has a configuration including at least the above-described light source and a color conversion composition or a color conversion sheet. When the light source unit includes a color conversion composition, the method of arranging the light source and the color conversion composition is not particularly limited, and may have a configuration in which the color conversion composition is directly applied to the light source. A configuration in which the color conversion composition is applied to a separated film, glass, or the like may be employed. When the light source unit includes a color conversion sheet, the arrangement method of the light source and the color conversion sheet is not particularly limited, and may have a configuration in which the light source and the color conversion sheet are in close contact, or the light source and the color conversion sheet It may take a remote phosphor format separated from the remote phosphor. In addition, the light source unit may be configured to further include a color filter in order to increase color purity.

As described above, the excitation light having a wavelength of 400 nm or more and 500 nm or less has relatively small excitation energy, and can prevent decomposition of a luminescent substance such as a compound represented by the general formula (2). Therefore, it is preferable that the light source included in the light source unit be a light emitting diode having a maximum light emission in a wavelength range of 400 nm or more and 500 nm or less. Further, the light source preferably has a maximum emission in a wavelength range of 430 nm to 480 nm, and more preferably has a maximum emission in a wavelength range of 450 nm to 470 nm. The light source unit according to the present invention can be used for applications such as displays, lighting, interiors, signs, and signboards, and is particularly suitably used for displays and lighting.
<Display and lighting device>
The display according to the embodiment of the present invention includes at least the light source unit including the light source and the color conversion sheet as described above. For example, a display such as a liquid crystal display uses the above-described light source unit as a backlight unit.

  Further, the lighting device according to the embodiment of the present invention includes at least the light source unit including the light source and the color conversion sheet as described above. For example, this lighting device combines a blue LED light source as a light source unit, a color conversion sheet or a color conversion composition that converts blue light from the blue LED light source into light having a longer wavelength, and Is configured to emit light.

  Hereinafter, the present invention will be described with reference to examples, but the present invention is not limited to these examples.

  In the following Examples and Comparative Examples, Compounds D-1 to D-4 and E-1 to E-3 are the compounds shown below. In addition, the maximum value εmax of the molar extinction coefficient ε in the entire wavelength range from 400 nm to 800 nm of E-1 to E-3 is 50 or less.

  The evaluation method for structural analysis is shown below.

<Measurement of ¹ H-NMR>
¹ H-NMR of the compound was measured using a superconducting FTNMR EX-270 (manufactured by JEOL Ltd.) in a heavy chloroform solution.

<Measurement of absorption spectrum>
The absorption spectrum of the compound was measured using a U-3200 type spectrophotometer (manufactured by Hitachi, Ltd.) by dissolving the compound in toluene at a concentration of 1 × 10 ⁻⁶ mol / L.

<Measurement of fluorescence spectrum>
The fluorescence spectrum of the compound was obtained by dissolving the compound in toluene at a concentration of 1 × 10 ⁻⁶ mol / L using a F-2500 type spectrofluorometer (manufactured by Hitachi, Ltd.) and exciting at a wavelength of 460 nm. The fluorescence spectrum was measured.

<Measurement of color conversion characteristics>
In the measurement of the color conversion characteristics, a current of 30 mA was passed through the surface light emitting device with the color conversion sheet and the prism sheet mounted on the surface light emitting device on which a blue LED element having an emission peak wavelength of 447 nm was mounted. The LED element was turned on, and the emission spectrum, chromaticity, and luminance were measured using a spectroradiometer (CS-1000, manufactured by Konica Minolta).

<Light durability test>
In the light durability test, a current of 100 mA was passed through the surface light emitting device with the color conversion sheet and the prism sheet mounted on the surface light emitting device equipped with a blue LED element having an emission peak wavelength of 447 nm. The LED element was turned on, and the initial luminance was measured using a spectral radiance meter (CS-1000, manufactured by Konica Minolta). Thereafter, the light durability was evaluated by continuously irradiating light from the blue LED element under an environment of 50 ° C. and 27% RH, and observing a time until the luminance decreased by a certain amount. However, the luminance was measured in a state where the color conversion sheet and the surface light-emitting device were taken out of the oven and cooled to room temperature.

<Measurement of molar extinction coefficient>
In the same manner as in the above absorption spectrum measurement method, the compound was dissolved in toluene or ethanol at 1 × 10 ⁻⁵ mol / L, 5 × 10 ⁻⁵ mol / L, 1 × 10 ⁻⁴ mol / L, and 5 × 10 ⁻⁴ mol. / L, and dissolved at 1 × 10 ⁻³ mol / L, and the respective absorption spectra were measured. From the obtained absorption spectrum, the absorbance at each wavelength was calculated, and a calibration curve was created from a graph having the absorbance on the vertical axis and the molar concentration (mol / L) on the horizontal axis, and the molar extinction coefficient for each wavelength was calculated. I asked.

Synthesis Example 1
Method for synthesizing compound D-2 3,5-dibromobenzaldehyde (3.0 g), 4- (methoxycarbonyl) phenylboronic acid (5.4 g), tetrakis (triphenylphosphine) palladium (0) (0.4 g), Potassium carbonate (2.0 g) was charged into the flask and purged with nitrogen. To this was added degassed toluene (30 mL) and degassed water (10 mL), and the mixture was refluxed for 4 hours. The reaction solution was cooled to room temperature, and the organic layer was separated and washed with saturated saline. The organic layer was dried over magnesium sulfate, and after filtration, the solvent was distilled off. The obtained reaction product was purified by silica gel chromatography to obtain 3,5-bis [4- (methoxycarbonyl) phenyl] benzaldehyde (3.5 g) as a white solid.

  3,5-Bis [4- (methoxycarbonyl) phenyl] benzaldehyde (1.5 g) and 2,4-dimethylpyrrole (0.7 g) were put into a reaction solution, and dehydrated dichloromethane (200 mL) and trifluoroacetic acid (1 drop) ) And stirred for 4 hours under a nitrogen atmosphere. A solution of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (0.85 g) in dehydrated dichloromethane was added, and the mixture was further stirred for 1 hour. After completion of the reaction, boron trifluoride diethyl ether complex (7.0 mL) and diisopropylethylamine (7.0 mL) were added, and the mixture was stirred for 4 hours. Water (100 mL) was further added and stirred, and the organic layer was separated. did. The organic layer was dried over magnesium sulfate, and after filtration, the solvent was distilled off. The obtained reaction product was purified by silica gel chromatography to obtain 0.4 g of the following compound D-2 (18% yield).

_{^{1 H-NMR (CDCl 3,}} ppm): 8.01 (s, 1H), 7.63-7.48 (m, 10H), 6.00 (s, 2H), 3.96 (s, 6H) .

  The absorption spectrum of this compound was as shown in FIG. 9, and the compound exhibited light absorption characteristics with a blue excitation light source (460 nm). The fluorescence spectrum was as shown in FIG. 10 and showed a sharp emission peak in the green region.

  Compounds D-1, D-3, and D-4 were synthesized using a known method, as in the above Synthesis Examples.

Example 1
In Example 1 of the present invention, an acrylic resin “Oricox KC-7000” (manufactured by Kyoeisha Chemical Co., Ltd.) was used as a binder resin, and 100 parts by weight of the binder resin was used as a component (A) to obtain a compound D-. 0.40 parts by weight of 1, 1 part by weight of compound E-1 as the component (C), 150 parts by weight of toluene as a solvent, and 150 parts by weight of 1-methoxy-2-propanol were mixed. These mixtures were stirred and defoamed at 300 rpm for 30 minutes using a planetary stirring and defoaming apparatus “Mazerustar KK-400” (manufactured by Kurabo Industries) to obtain a color conversion composition.

  Then, using a slit die coater, the color conversion composition was applied onto a base layer “Lumirror” U34 (manufactured by Toray Industries, Inc., thickness 75 μm), heated at 120 ° C. for 20 minutes, and dried. A color conversion layer having an average film thickness of 16 μm was formed.

  Finally, after laminating a diffusion film ("Texcell" (registered trademark) TDF127, manufactured by Toray Advanced Materials Co., Ltd.), the film was aged at 60 ° C for 1 hour to obtain a color conversion sheet.

  When the blue LED light was color-converted using this color conversion sheet, only green light emission region was extracted. As a result, high-purity green light emission having a peak wavelength of 527 nm and a half-value width of the emission spectrum at the peak wavelength of 32 nm was obtained. . Further, according to the above method, when the light from the blue LED element was continuously irradiated in an environment of 50 ° C. and 27% RH, the time required for the luminance to decrease by 10% was 150 hours. Table 1 shows the results.

Comparative Example 1
A color conversion sheet was prepared and evaluated in the same manner as in Example 1 except that the component (C) was not mixed. Table 1 shows the results.

Examples 2 and 3
A color conversion sheet was prepared and evaluated in the same manner as in Example 1 except that the compounds described in Table 1 were used as the component (C). Table 1 shows the results.

Example 4
A color conversion sheet was prepared and evaluated in the same manner as in Example 1, except that 0.30 part by weight of the compound D-2 was used as the component (A). Table 1 shows the results.

Comparative Example 2
A color conversion sheet was prepared and evaluated in the same manner as in Example 4 except that the component (C) was not mixed. Table 1 shows the results.

Example 5
A color conversion sheet was prepared and evaluated in the same manner as in Example 1, except that 0.25 part by weight of the compound D-3 was used as the component (A). Table 1 shows the results.

Comparative Example 3
A color conversion sheet was prepared and evaluated in the same manner as in Example 5 except that the component (C) was not mixed. Table 1 shows the results.

Example 6
A color conversion sheet was prepared in the same manner as in Example 1, except that 0.10 part by weight of the compound D-4 was used as the component (A).

  When color conversion of blue LED light was performed using this color conversion sheet, only the red light emission region was extracted, and high color purity red light emission having a peak wavelength of 630 nm and a half width of the emission spectrum at the peak wavelength of 49 nm was obtained. . Further, according to the above method, when the light from the blue LED element was continuously irradiated in an environment of 50 ° C. and 27% RH, the time required for the luminance to decrease by 10% was 270 hours. Table 2 shows the results.

Comparative Example 4
A color conversion sheet was prepared and evaluated in the same manner as in Example 6, except that the component (C) was not mixed. Table 2 shows the results.

Example 7
A color conversion sheet was prepared and evaluated in the same manner as in Example 6, except that the compounds described in Table 2 were used as the component (C). Table 2 shows the results.

1 Color conversion sheet 10 Base layer 11 Color conversion layer 11A Color conversion layer 11B Color conversion layer 12 Barrier layer 13 Transparent intermediate layer

Claims (15)

A color conversion composition for converting incident light into light having a longer wavelength than the incident light, comprising the following components (A), (B) and (C):
(A) at least one kind of organic light-emitting material containing an ester bond (B) binder resin (C) a compound having a partial structure represented by the general formula (1) and having a molecular weight of 2000 or less

(Y is a single bond or C = O. A black circle indicates a covalent bond to an adjacent atom.)
A color conversion composition comprising: The color conversion composition according to claim 1, wherein in the general formula (1), Y is C = O. The color conversion composition according to claim 2, wherein the component (C) is an acid anhydride of an aliphatic hydrocarbon acid or an acid anhydride of an aromatic hydrocarbon acid. The color conversion composition according to claim 2, wherein the component (C) is an acid dianhydride. The color conversion composition according to claim 1, wherein in the general formula (1), Y is a single bond, and the component (C) is a cyclic ester compound. The color conversion composition according to any one of claims 1 to 5, wherein the component (C) does not contain any of a nitrogen atom, a phosphorus atom, and a sulfur atom. The color conversion composition according to any one of claims 1 to 6, wherein the component (A) contains a compound represented by the general formula (2).

(X is C—R ⁷ or N. Each of R ^{1 to} R ⁹ may be the same or different and includes hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, Hydroxy, thiol, alkoxy, alkylthio, arylether, arylthioether, aryl, heteroaryl, halogen, cyano, aldehyde, carbonyl, carboxyl, ester, carbamoyl, amino, nitro Group, a silyl group, a siloxanyl group, a boryl group, a sulfo group, a phosphine oxide group, and a condensed ring and an aliphatic ring formed between adjacent substituents, provided that R ^{1 to} R ⁹ , At least one of which is an ester group or a substituent substituted with an ester group.) In the above formula (2), X is C-R ^7, a group R ⁷ is represented by the general formula (3), the color conversion composition according to claim 7.

(R is hydrogen, alkyl, cycloalkyl, heterocyclic, alkenyl, cycloalkenyl, alkynyl, hydroxyl, thiol, alkoxy, alkylthio, arylether, arylthioether, aryl, hetero Selected from the group consisting of aryl, halogen, cyano, aldehyde, carbonyl, carboxyl, ester, carbamoyl, amino, nitro, silyl, siloxanyl, boryl, sulfo, and phosphine oxide groups K is an integer of 1 to 3. When k is 2 or more, r may be the same or different.) 9. The color conversion according to claim 7, wherein in the general formula (2), R ¹ , R ³ , R ^4, and R ⁶ may be the same or different, and each is a substituted or unsubstituted phenyl group. Composition. 9. The color conversion according to claim 7, wherein, in the general formula (2), R ¹ , R ³ , R ^4, and R ⁶ may be the same or different and are a substituted or unsubstituted alkyl group. Composition. In the general formula (2), at least one of R ² and R ^5, which may be the same or different and each is a substituted or unsubstituted ester group, the color conversion according to any of claims 7-10 Composition. A color conversion sheet comprising a color conversion layer obtained by curing the color conversion composition according to claim 1. A light source unit comprising: a light source; and the color conversion sheet according to claim 12. The light source unit according to claim 13, wherein the light source is a light emitting diode having a maximum light emission in a wavelength range of 400 nm or more and 500 nm or less. A display or a lighting device comprising the light source unit according to claim 13.

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