WO2024024590A1 - Particulate color conversion material, color conversion member, and light source unit, display, lighting device, and color conversion substrate including same - Google Patents

Abstract

A particulate color conversion material according to one embodiment of the present invention has a matrix resin and at least one type of light-emitting material. The at least one type of light-emitting material includes an organic light-emitting material that emits delayed fluorescence having a half-width of 50 nm or less.

Description

Particulate color conversion materials, color conversion members, light source units containing the same, displays, lighting devices, and color conversion substrates

The present invention relates to a particulate color conversion material, a color conversion member, and a light source unit, display, lighting device, and color conversion substrate including the same.

There is active research into applying multicolor technology using color conversion methods to liquid crystal displays, organic EL displays, lighting devices, etc. Color conversion refers to converting light emitted from a light emitter into light with a longer wavelength, and includes, for example, converting blue light into green or red light.

By forming a composition having this color conversion function (hereinafter referred to as "color conversion composition") into a sheet and combining it with, for example, a blue light source, the three primary colors of blue, green, and red can be extracted from the blue light source, that is, white light. It becomes possible to take out. A white light source that combines such a blue light source and a sheet with a color conversion function (hereinafter referred to as "color conversion sheet") is used as a light source unit such as a backlight unit, and this light source unit, a liquid crystal drive part, and a color filter are used as a light source unit such as a backlight unit. By combining these, it becomes possible to create a full-color display. Further, a white light source that is a combination of a blue light source and a color conversion sheet can be used as it is as a white light source (illumination device) such as LED lighting.

Improving color reproducibility is an issue for liquid crystal displays that use color conversion methods. In order to improve color reproducibility, it is effective to narrow the half-widths of the blue, green, and red emission spectra of the light source unit and increase the color purity of each of the blue, green, and red colors. As a means to solve this problem, a technique has been proposed in which quantum dots made of inorganic semiconductor fine particles are used as a component of a color conversion composition (for example, see Patent Document 1).

Additionally, a technique has been proposed in which, instead of quantum dots, an organic luminescent material with less concern about toxic elements such as cadmium is used as a component of the color conversion composition. Examples of techniques using organic luminescent materials as components of color conversion compositions include those using coumarin derivatives (see, for example, Patent Document 2), those using rhodamine derivatives (see, for example, Patent Document 3), and those using pyrromethene derivatives. (for example, see Patent Document 4) has been disclosed. Further, as an example of a technique for preventing deterioration of an organic light-emitting material and improving durability, a technique of adding a light stabilizer has also been disclosed (see, for example, Patent Document 5).

Japanese Patent Application Publication No. 2012-22028 JP2007-273440A Japanese Patent Application Publication No. 2001-164245 Japanese Patent Application Publication No. 2011-241160 International Publication No. 2011/149028

In the technology using quantum dots described in Patent Document 1, the half-value widths of green and red emission spectra are certainly narrow, and color reproducibility is improved. On the other hand, quantum dots are sensitive to heat, moisture and oxygen in the air, and lack sufficient durability. In addition, quantum dots also have problems such as containing cadmium.

In addition, in recent years, the illuminance required for the light source unit of a liquid crystal display has increased with the advancement of high definition such as 4K and 8K, high dynamic range (HDR), and high contrast due to local dimming. For this reason, the temperature of the light source unit increases due to drive heat.

Although it is certainly possible to improve color reproducibility with the techniques using organic light-emitting materials described in Patent Documents 2 to 4, they lack durability at high temperatures. Further, although existing techniques such as the light stabilizer described in Patent Document 5 have the effect of improving durability, they are insufficient as techniques for improving durability at high temperatures. In particular, color conversion materials using organic light-emitting materials have a problem in that their durability deteriorates significantly at high temperatures, and the existing techniques described above have not yet been able to satisfactorily solve this problem.

The problem to be solved by the present invention is to improve color reproducibility and durability in color conversion materials used in light source units such as backlight units, displays such as liquid crystal displays, and lighting devices such as LED lighting. In particular, it is important to improve durability under high temperatures.

In order to solve the above-mentioned problems and achieve the objects, the present invention has the configuration described in any one of [1] to [19] below.

That is, the particulate color conversion material according to the present invention is [1] a particulate color conversion material comprising a matrix resin and at least one kind of luminescent material, wherein the at least one kind of luminescent material has a half-width of 50 nm. It is characterized in that it contains an organic light-emitting material that emits delayed fluorescence as described below.

[2] In the invention described in [1] above, the particulate color conversion material according to the present invention is characterized in that the organic light-emitting material is a compound containing a partial structure represented by general formula (1). It is characterized by

(In general formula (1), B is a boron atom, N is a nitrogen atom, and C is a carbon atom. n is an integer from 0 to 2. When n is 0, the general formula The partial structure represented by (1) shows a direct bond structure between B and N.)

[3] In the invention described in [2] above, the particulate color conversion material according to the present invention is a compound in which the organic light-emitting material includes two or more partial structures represented by the general formula (1). It is characterized by:

[4] In the invention described in any one of [1] to [3] above, the particulate color conversion material according to the present invention is characterized in that the organic light-emitting material has the general formula (2) or the general formula ( It is characterized by containing the compound represented by 3).

(In general formula (2) or general formula (3), ring Za, ring Zb and ring Zc each independently represent a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms, or a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms, or a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms. It is a heteroaryl ring having 6 to 30 ring carbon atoms. Z ¹ and Z ² are each independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra), or a sulfur atom. Z ¹ is NRa In this case, the substituent Ra may be combined with ring Za or ring Zb to form a ring. When Z ² is NRa, the substituent Ra may be combined with ring Za or ring Zc to form a ring. E is a boron atom, a phosphorus atom, SiRa (a silicon atom having a substituent Ra), or P=O. E ¹ and E ² each independently represent a BRa (a boron atom having a substituent Ra). ), PRa (phosphorous atom having a substituent Ra), SiRa ₂ (silicon atom having two substituents Ra), P(=O)Ra ₂ (phosphine oxide having two substituents Ra) or P(=S ) Ra ₂ (phosphine sulfide having two substituents Ra), C=O (carbonyl group), S(=O) or S(=O) ₂ . ^{E 1} is BRa, PRa, SiRa ₂ , P( When =O)Ra ₂ or P(=S)Ra ₂ , the substituent Ra may be combined with ring Za or ring Zb to form a ring. E ² is BRa, PRa, SiRa ₂ , P When (=O)Ra ₂ or P(=S)Ra ₂ , the substituent Ra may be bonded with ring Za or ring Zc to form a ring. Each substituent Ra independently represents hydrogen , substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, substituted or unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkenyl group, substituted or unsubstituted alkynyl group, hydroxyl group, thiol group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted aryl ether group, substituted or unsubstituted arylthioether group, halogen, cyano group, aldehyde group, substituted or unsubstituted carbonyl group, substituted or unsubstituted carboxyl group, substituted or unsubstituted oxycarbonyl group, substituted or unsubstituted ester group, substitution or unsubstituted carbamoyl group, substituted or unsubstituted amide group, sulfonyl group, substituted or unsubstituted sulfonic acid ester group, substituted or unsubstituted sulfonamide group, substituted or unsubstituted amino group, substituted or unsubstituted Formed between imino group, nitro group, substituted or unsubstituted silyl group, substituted or unsubstituted siloxanyl group, substituted or unsubstituted boryl group, substituted or unsubstituted phosphine oxide group, and adjacent substituents A substituent selected from fused rings and aliphatic rings. Further, the substituent Ra may be further substituted with the selected substituent, and these substituents may be further substituted with the selected substituent. )

Further, in the particulate color conversion material according to the present invention, in the invention described in [5] above [4], E in the general formula (2) is a boron atom, and E ¹ and It is characterized in that E ² is BRa.

Furthermore, the color conversion member according to the present invention is characterized in that it comprises a support containing the particulate color conversion material according to [6] any one of [1] to [5] above.

[7] In the invention described in [6] above, the color conversion member according to the present invention is a first light emitting material in which the color conversion member emits light whose peak wavelength is observed in a region of 500 nm or more and less than 580 nm. and a first matrix resin, and a second particulate color consisting of a second light-emitting material and a second matrix resin that emits light whose peak wavelength is observed in a region of 580 nm or more and 750 nm or less. and a conversion material.

[8] In the invention described in [7] above, the color conversion member according to the present invention is characterized in that the first light-emitting material includes at least an organic light-emitting material that emits delayed fluorescence with a half-width of 50 nm or less. It is characterized by

[9] In the invention described in [6] or [7] above, the color conversion member according to the present invention is characterized in that the second luminescent material contains at least a compound represented by general formula (4). It is characterized by

(In ^the general formula ( ⁴ ) ^, group, cycloalkenyl group, alkynyl group, hydroxyl group, thiol group, alkoxy group, alkylthio group, aryl ether group, arylthioether group, aryl group, heteroaryl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, oxy R ¹ selected from carbonyl groups, carbamoyl groups, amino groups, nitro groups, silyl groups, siloxanyl groups, boryl groups, phosphine oxide groups, and fused rings and aliphatic rings formed between adjacent substituents. ~R ⁹ may each be independently substituted.The substituents for each of R ¹ ~R ⁹ include hydrogen, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or Unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkenyl group, substituted or unsubstituted alkynyl group, hydroxyl group , thiol group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted aryl ether group, substituted or unsubstituted arylthioether group, halogen, cyano group, aldehyde group, substituted or unsubstituted carbonyl group, substituted or unsubstituted carboxyl group, substituted or unsubstituted oxycarbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted amide group, sulfonyl group, substituted or Unsubstituted sulfonic acid ester group, substituted or unsubstituted sulfonamide group, substituted or unsubstituted amino group, substituted or unsubstituted imino group, nitro group, substituted or unsubstituted silyl group, substituted or unsubstituted siloxanyl group, substituted or unsubstituted boryl group, substituted or unsubstituted phosphine oxide group, and fused rings and aliphatic rings formed between adjacent substituents.)

[10] The color conversion member according to the present invention is the invention according to any one of [6] to [9] above, wherein the support is one of any one of [1] to [5] above. It is characterized by containing the particulate color conversion material described in 1. and at least one kind of luminescent material.

[11] In the invention described in [10] above, the color conversion member according to the present invention is characterized in that the at least one kind of luminescent material is a compound containing a partial structure represented by general formula (1), a compound containing a partial structure represented by general formula (1), It is characterized by containing at least one of the compound represented by (2) and the compound represented by general formula (3).

(In general formula (1), B is a boron atom, N is a nitrogen atom, and C is a carbon atom. n is an integer from 0 to 2. When n is 0, the general formula The partial structure represented by (1) shows a direct bond structure between B and N.)

(In general formula (2) or general formula (3), ring Za, ring Zb and ring Zc each independently represent a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms, or a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms, or a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms. It is a heteroaryl ring having 6 to 30 ring carbon atoms. Z ¹ and Z ² are each independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra), or a sulfur atom. Z ¹ is NRa In this case, the substituent Ra may be combined with ring Za or ring Zb to form a ring. When Z ² is NRa, the substituent Ra may be combined with ring Za or ring Zc to form a ring. E is a boron atom, a phosphorus atom, SiRa (a silicon atom having a substituent Ra), or P=O. E ¹ and E ² each independently represent a BRa (a boron atom having a substituent Ra). ), PRa (phosphorous atom having a substituent Ra), SiRa ₂ (silicon atom having two substituents Ra), P(=O)Ra ₂ (phosphine oxide having two substituents Ra) or P(=S ) Ra ₂ (phosphine sulfide having two substituents Ra), C=O (carbonyl group), S(=O) or S(=O) ₂ . ^{E 1} is BRa, PRa, SiRa ₂ , P( When =O)Ra ₂ or P(=S)Ra ₂ , the substituent Ra may be combined with ring Za or ring Zb to form a ring. E ² is BRa, PRa, SiRa ₂ , P When (=O)Ra ₂ or P(=S)Ra ₂ , the substituent Ra may be bonded with ring Za or ring Zc to form a ring. Each substituent Ra independently represents hydrogen , substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, substituted or unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkenyl group, substituted or unsubstituted alkynyl group, hydroxyl group, thiol group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted aryl ether group, substituted or unsubstituted arylthioether group, halogen, cyano group, aldehyde group, substituted or unsubstituted carbonyl group, substituted or unsubstituted carboxyl group, substituted or unsubstituted oxycarbonyl group, substituted or unsubstituted ester group, substitution or unsubstituted carbamoyl group, substituted or unsubstituted amide group, sulfonyl group, substituted or unsubstituted sulfonic acid ester group, substituted or unsubstituted sulfonamide group, substituted or unsubstituted amino group, substituted or unsubstituted Formed between imino group, nitro group, substituted or unsubstituted silyl group, substituted or unsubstituted siloxanyl group, substituted or unsubstituted boryl group, substituted or unsubstituted phosphine oxide group, and adjacent substituents A substituent selected from fused rings and aliphatic rings. Further, the substituent Ra may be further substituted with the selected substituent, and these substituents may be further substituted with the selected substituent. )

[12] In the invention described in [10] above, the color conversion member according to the present invention is characterized in that the at least one kind of luminescent material contains at least a compound represented by general formula (4). Features.

(In ^the general formula ( ⁴ ) ^, group, cycloalkenyl group, alkynyl group, hydroxyl group, thiol group, alkoxy group, alkylthio group, aryl ether group, arylthioether group, aryl group, heteroaryl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, oxy R ¹ selected from carbonyl groups, carbamoyl groups, amino groups, nitro groups, silyl groups, siloxanyl groups, boryl groups, phosphine oxide groups, and fused rings and aliphatic rings formed between adjacent substituents. ~R ⁹ may each be independently substituted.The substituents for each of R ¹ ~R ⁹ include hydrogen, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or Unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkenyl group, substituted or unsubstituted alkynyl group, hydroxyl group , thiol group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted aryl ether group, substituted or unsubstituted arylthioether group, halogen, cyano group, aldehyde group, substituted or unsubstituted carbonyl group, substituted or unsubstituted carboxyl group, substituted or unsubstituted oxycarbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted amide group, sulfonyl group, substituted or Unsubstituted sulfonic acid ester group, substituted or unsubstituted sulfonamide group, substituted or unsubstituted amino group, substituted or unsubstituted imino group, nitro group, substituted or unsubstituted silyl group, substituted or unsubstituted siloxanyl group, substituted or unsubstituted boryl group, substituted or unsubstituted phosphine oxide group, and fused rings and aliphatic rings formed between adjacent substituents.)

[13] In the invention described in any one of [6] to [12] above, the color conversion member according to the present invention is characterized in that the support has an oxygen permeability of 1.0 cc/m ² ·day · It is characterized by being less than ATM.

[14] In the invention described in any one of [6] to [13] above, the color conversion member according to the present invention is provided with an oxygen barrier layer on at least a part of the surface of the support. It is characterized by having.

Further, the light source unit according to the present invention includes [15] a light source, and the particulate color conversion material according to any one of [1] to [5] above or any one of [6] to [14] above. It is characterized by comprising the color conversion member described in .

[16] The light source unit according to the present invention is characterized in that in the invention described in [15] above, the light source is a light emitting diode having maximum emission in a wavelength range of 400 nm or more and 500 nm or less.

[17] The display according to the present invention is characterized by comprising the light source unit described in [15] or [16] above.

[18] The lighting device according to the present invention is characterized by comprising the light source unit described in [15] or [16] above.

[19] The particulate color conversion material according to any one of [1] to [5] above or any one of [6] to [14] above. It is characterized by containing the color conversion member described above.

The particulate color conversion material according to the present invention and the color conversion member using the same have both high color purity of light emission and high durability, so that both improved color reproducibility and improved durability can be achieved. This has the effect of making it possible.

FIG. 1 is a schematic cross-sectional view showing a first example of a color conversion member according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a second example of the color conversion member according to the embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a third example of the color conversion member according to the embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing a fourth example of the color conversion member according to the embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing a fifth example of the color conversion member according to the embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing a sixth example of the color conversion member according to the embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing a seventh example of the color conversion member according to the embodiment of the present invention.

Preferred embodiments of a particulate color conversion material, a color conversion member, a light source unit including the same, a display, a lighting device, and a color conversion substrate according to the present invention will be specifically described below. The present invention is not limited to this form, and can be implemented with various changes depending on the purpose and use.

A particulate color conversion material according to an embodiment of the present invention (hereinafter sometimes abbreviated as "particulate color conversion material of the present invention") is a particulate color conversion material having a matrix resin and at least one luminescent material. It is the material. Specifically, the particulate color conversion material of the present invention is a particulate color conversion material containing at least one kind of luminescent material in a matrix resin. In the particulate color conversion material of the present invention, at least one type of luminescent material contained in the matrix resin includes an organic luminescent material that emits delayed fluorescence with a half-width of 50 nm or less. That is, the particulate color conversion material of the present invention has at least the organic light emitting material in the matrix resin. Note that details of the luminescent material included in the particulate color conversion material of the present invention will be described later.

Further, a color conversion member according to an embodiment of the present invention (hereinafter sometimes abbreviated as "color conversion member of the present invention") includes a support containing the particulate color conversion material. That is, the color conversion member of the present invention includes the particulate color conversion material of the present invention and a support containing the particulate color conversion material.

Typical structural examples of particulate color conversion materials and color conversion members according to embodiments of the present invention include those shown in FIGS. 1 to 7, for example. FIG. 1 is a schematic cross-sectional view showing a first example of a color conversion member according to an embodiment of the present invention. FIG. 2 is a schematic cross-sectional view showing a second example of the color conversion member according to the embodiment of the present invention. FIG. 3 is a schematic cross-sectional view showing a third example of the color conversion member according to the embodiment of the present invention. FIG. 4 is a schematic cross-sectional view showing a fourth example of the color conversion member according to the embodiment of the present invention. FIG. 5 is a schematic cross-sectional view showing a fifth example of the color conversion member according to the embodiment of the present invention. FIG. 6 is a schematic cross-sectional view showing a sixth example of the color conversion member according to the embodiment of the present invention. FIG. 7 is a schematic cross-sectional view showing a seventh example of the color conversion member according to the embodiment of the present invention.

As shown in FIG. 1, the color conversion member 1A of the first example includes a particulate color conversion material 2a and a support 3a containing the particulate color conversion material 2a. As shown in FIG. 1, particulate color conversion material 2a is dispersed inside the support 3a. The particulate color conversion material 2a is an example of the particulate color conversion material of the present invention, and includes at least one kind of luminescent material contained in a matrix resin. In the structural example shown in FIG. 1, the color conversion member 1A has a single layer structure in which one type of particulate color conversion material 2a is contained in a dispersed state in a single layer support 3a.

As shown in FIG. 2, the color conversion member 1B of the second example includes two types of particulate color conversion materials 2a and 2b, a support body 3a containing the two types of particulate color conversion materials 2a and 2b, Equipped with. As shown in FIG. 2, particulate color conversion material 2a and particulate color conversion material 2b are respectively dispersed inside the support 3a. Both the particulate color conversion material 2a and the particulate color conversion material 2b contain at least one type of luminescent material in a matrix resin. For example, the particulate color conversion material 2a and the particulate color conversion material 2b have different light emission characteristics (color conversion characteristics), such as different emission colors. In the structural example shown in FIG. 2, the color conversion member 1B has a single layer structure in which two types of particulate color conversion material 2a and particulate color conversion material 2b are contained in a dispersed state in a single layer support 3a. are doing.

As shown in FIG. 3, the color conversion member 1C of the third example includes two types of particulate color conversion materials 2a and 2b, and a two-layer support containing each of the two types of particulate color conversion materials 2a and 2b. It includes bodies 3a and 3b. Among these two layers of supports 3a and 3b, one type of particulate color conversion material 2a is dispersed inside one support 3a, and another type of particles is dispersed inside the other support 3b. The color changing material 2b is dispersed therein. Note that these particulate color conversion material 2a and particulate color conversion material 2b are the same as the color conversion member 1B of the second example described above. In the structural example shown in FIG. 3, the color conversion member 1C includes a single layer support 3a containing a particulate color conversion material 2a in a dispersed state, and a particulate color conversion material different from the particulate color conversion material 2a. It has a laminated structure in which a single-layer support 3b containing 2b in a dispersed state is laminated.

As shown in FIG. 4, the color conversion member 1D of the fourth example includes one type of particulate color conversion material 2a, a support body 3a containing the one type of particulate color conversion material 2a, and this support body 3a. an oxygen barrier layer 11 covering at least a portion of the surface of the oxygen barrier layer 11 . The oxygen barrier layer 11 is a layer having oxygen barrier properties. For example, as shown in FIG. 4, the oxygen barrier layer 11 covers both end surfaces in the thickness direction of the support 3a containing the particulate color conversion material 2a (the upper and lower surfaces of the support 3a in FIG. 4). It is formed. Note that the particulate color conversion material 2a and support body 3a shown in FIG. 4 are the same as the color conversion member 1A (see FIG. 1) of the first example described above. In the structural example shown in FIG. 4, the color conversion member 1D is attached to both end faces in the thickness direction of the support 3a containing the particulate color conversion material 2a, similarly to the color conversion member 1A of the first example shown in FIG. It has a laminated structure in which oxygen barrier layers 11 are laminated.

As shown in FIG. 5, the color conversion member 1E of the fifth example includes two types of particulate color conversion materials 2a and 2b, a support body 3a containing the two types of particulate color conversion materials 2a and 2b, An oxygen barrier layer 11 covering at least a portion of the surface of the support 3a is provided. For example, as shown in FIG. 5, the oxygen barrier layer 11 is formed on both end surfaces in the thickness direction of a support 3a containing two types of particulate color conversion materials 2a and 2b (in FIG. 5, the upper and lower surfaces of the support 3a). ) is formed to cover the Note that the particulate color conversion materials 2a, 2b and the support 3a shown in FIG. 5 are the same as the color conversion member 1B of the second example described above (see FIG. 2). In the structural example shown in FIG. 5, the color conversion member 1E includes both ends in the thickness direction of a support 3a containing particulate color conversion materials 2a and 2b, similar to the color conversion member 1B of the second example shown in FIG. It has a laminated structure in which an oxygen barrier layer 11 is laminated on the surface.

As shown in FIG. 6, the color conversion member 1F of the sixth example includes two types of particulate color conversion materials 2a and 2b, and a two-layer support containing each of the two types of particulate color conversion materials 2a and 2b. The oxygen barrier layer 11 covers at least a portion of each surface of these two layers of supports 3a and 3b. For example, as shown in FIG. 6, the oxygen barrier layer 11 is formed between one end surface in the thickness direction of the support 3a containing the particulate color conversion material 2a (the upper surface of the support 3a in FIG. 6) and the particulate color conversion material 2a. It is formed so as to cover one end surface in the thickness direction of the support 3b containing the material 2b (the lower surface of the support 3b in FIG. 6). Note that the laminate of two layers of supports 3a and 3b each containing two types of particulate color conversion materials 2a and 2b shown in FIG. The same is true. In the structural example shown in FIG. 6, the color conversion member 1F is a laminate in which oxygen barrier layers 11 are laminated on both end faces in the thickness direction of the laminate, similar to the color conversion member 1C of the third example shown in FIG. It has a structure.

As shown in FIG. 7, the color conversion member 1G of the seventh example includes one type of particulate color conversion material 2a, a support 3a containing the one type of particulate color conversion material 2a, and a support 3a containing the one type of particulate color conversion material 2a. an oxygen barrier layer 11 covering the entire surface of the device. For example, as shown in FIG. 7, the oxygen barrier layer 11 is formed on both end surfaces in the thickness direction of the support 3a containing the particulate color conversion material 2a (in FIG. 7, the upper and lower surfaces of the support 3a), and It is formed so as to cover the entire side surface (each end surface in the direction perpendicular to the thickness direction) of the body 3a. Note that the particulate color conversion material 2a and the support 3a shown in FIG. 7 are the same as the color conversion member 1A (see FIG. 1) of the first example described above. In the structural example shown in FIG. 7, the color conversion member 1G has an oxygen barrier layer 11 on the entire surface of the support 3a containing the particulate color conversion material 2a, similar to the color conversion member 1A of the first example shown in FIG. It has a laminated structure.

Note that the color conversion member of the present invention is not limited to those illustrated in FIGS. 1 to 7 described above. For example, the color conversion member of the present invention may contain three or more types of particulate color conversion materials inside a single layer support, or may include inside at least one layer of a multilayer support. It may contain two or more types of particulate color conversion materials, or it may have a laminated structure in which three or more layers of supports containing one or more types of particulate color conversion materials are laminated. . Further, the color conversion member of the present invention has a plurality of layers of supports (for example, supports 3a and 3b) between two oxygen barrier layers 11, like the color conversion member 1F of the sixth example shown in FIG. In some cases, it may further include an oxygen barrier layer 11 interposed between these multiple layers of supports, or it may have a single layer structure similar to the color conversion member 1B of the second example shown in FIG. In the case where the color conversion member 1C has a laminated structure similar to the color conversion member 1C of the third example shown in FIG. It may have a layer 11. Further, the color conversion member of the present invention includes a support containing one or more particulate color conversion materials (for example, supports 3a and 3b illustrated in FIGS. 1 to 7). may have a structure that further includes a different luminescent material. In this case, the luminescent material is preferably contained in a dispersed state inside the support. Furthermore, between each layer of the laminated structure of the color conversion member of the present invention (for example, between the support 3a and the support 3b shown in FIG. 3, and between the support 3a and the oxygen barrier layer 11 shown in FIG. 4) may be provided with an adhesive layer or an adhesive layer.

<Light-emitting material>
A particulate color conversion material according to an embodiment of the present invention has at least one type of luminescent material (for example, an organic luminescent material) in a matrix resin. Here, the luminescent material in the present invention refers to a material that, when irradiated with some kind of light, emits light of a wavelength different from the wavelength of that light.

In order to achieve highly efficient color conversion, it is preferable that the luminescent material exhibits luminescent properties with high quantum yield. In general, examples of the luminescent material include known luminescent materials such as inorganic phosphors, fluorescent pigments, fluorescent dyes, and quantum dots. However, in the present invention, at least an organic luminescent material is used as one or more luminescent materials included in the particulate color conversion material from the viewpoint of uniformity of dispersion, reduction in usage amount, and reduction in environmental load. Further, the particulate color conversion material according to the embodiment of the present invention contains at least an organic light-emitting material in the matrix resin, and thus exhibits light emission with high color purity.

Among many organic light-emitting materials, particulate color conversion materials according to embodiments of the present invention include organic light-emitting materials that emit delayed fluorescence. Here, organic light emitting materials that emit delayed fluorescence are explained on pages 87 to 103 of "Cutting Edge Organic EL" (edited by Chinaya Adachi and Hiroshi Fujimoto, published by CMC Publishing). In that literature, by bringing the energy levels of the singlet excited state and triplet excited state of a luminescent material close together, the reverse energy transfer from the triplet excited state to the singlet excited state, which normally has a low transition probability, is increased. It is explained that thermally activated delayed fluorescence (TADF) occurs with high efficiency. Further, in FIG. 5 of the document, the mechanism of generation of delayed fluorescence is explained. Emission of delayed fluorescence can be confirmed by transient PL (Photo Luminescence) measurement.

It has also been reported that by matching the energy level of the singlet excited state and triplet excited state of a luminescent material, the reverse energy transfer from the triplet excited state to the singlet excited state can be accelerated. (Nature Photonics volume 14, pages 643-649 (2020)). Furthermore, active research is being conducted on compounds whose triplet excited state energy level is higher than the singlet excited state energy level of luminescent materials.

In this specification, organic light-emitting materials that transition from a triplet excited state to a singlet excited state and emit fluorescence, including organic light-emitting materials that exhibit thermally activated delayed fluorescence, are referred to as "organic light-emitting materials that emit fluorescence by transitioning from a triplet excited state to a singlet excited state with high efficiency". "Light-emitting material". Furthermore, hereinafter, the "organic light emitting material that emits delayed fluorescence" may be abbreviated as "delayed fluorescence material".

Normally, fluorescence is emitted from a singlet excited state generated after a luminescent material is photoexcited, and the triplet excited state of a luminescent material generated by intersystem crossing is thermally inactivated in a room temperature environment. Therefore, no fluorescence is emitted from the triplet excited state of the luminescent material. On the other hand, as mentioned above, even if a triplet excited state is generated in a delayed fluorescent material, it is quickly converted to a singlet excited state and then emits fluorescence, so it does not contribute to light emission in ordinary fluorescent materials. Triplet excited states that could not be produced can also contribute to fluorescence emission. Therefore, highly efficient light emission can be obtained.

Further, organic light-emitting materials in the triplet excited state usually have high reactivity. Furthermore, when the organic luminescent material is a luminescent material other than a delayed fluorescent material, the lifetime of the organic luminescent material in the triplet excited state is long. Therefore, organic light-emitting materials in a triplet excited state tend to react with surrounding molecules. For example, in the presence of oxygen, oxygen, which has high reactivity and high mobility, becomes a receiver of energy from the organic light-emitting material in the triplet excited state, producing singlet oxygen, which causes oxidative deterioration of the organic light-emitting material. It causes On the other hand, in the absence of oxygen, molecules surrounding the organic light-emitting material can become recipients of the energy. In other words, even if oxygen is not present and singlet oxygen is not produced, if a highly reactive organic luminescent material in the triplet excited state exists for a long time, the reaction between this organic luminescent material and surrounding molecules will occur. As this progresses, this organic light-emitting material deteriorates.

However, when the organic light-emitting material in the triplet excited state is a delayed fluorescent material, the triplet excited state delayed fluorescent material is quickly converted to the singlet excited state delayed fluorescent material. For this reason, the reaction between the delayed fluorescent material in the triplet excited state and the surrounding molecules is difficult to proceed, so the delayed fluorescent material is unlikely to deteriorate due to this reaction, and the delayed fluorescent material exhibits excellent durability. can. That is, in order to achieve high durability, the sooner the reverse intersystem crossing from the triplet excited state to the singlet excited state of the delayed fluorescent material occurs, the better. For example, the rate constant of this inverse intersystem crossing is preferably 1.0×10 ² s ⁻¹ or more.

As a molecular design that brings the energy level of the singlet excited state and the energy level of the triplet excited state close to each other, it is effective to combine an electron donor skeleton and an electron acceptor skeleton within the same molecule. By doing so, the HOMO (Highest Occupied Molecular Orbital) orbit and the LUMO (Lowest Unoccupied Molecular Orbital) orbit can be separated within the molecule. The electron donor skeleton and the electron acceptor skeleton may be bonded directly or may be bonded via a linking group. In this case, the linking group preferably has a skeleton containing an aromatic hydrocarbon.

Examples of the electron donor skeleton include a skeleton having an amine nitrogen atom. Among these, preferred are a skeleton containing diarylamine or triarylamine, a skeleton containing carbazole, a skeleton containing benzocarbazole, a skeleton containing indolocarbazole, a skeleton containing phenoxazine, and a skeleton containing phenothiazine. Among these, skeletons containing carbazole, skeletons containing benzocarbazole, skeletons containing indolocarbazole, and skeletons containing phenoxazine are more preferred, and skeletons containing carbazole and skeletons containing phenoxazine are even more preferred.

On the other hand, examples of the electron-accepting skeleton usually include a skeleton containing a substituent having electron-withdrawing properties (i.e., an electron-withdrawing group). An electron-withdrawing group is also called an electron-accepting group, and in organic electron theory, it is an atomic group that attracts electrons from a substituted atomic group through an induction effect or a resonance effect. Examples of the electron-withdrawing group include those having a positive value as the Hammett's substituent constant (σp (para)). The substituent constant (σp (para)) of Hammett's rule can be quoted from the Chemical Handbook, Basic Edition, Revised 5th Edition (page II-380). Although there are examples in which phenyl groups also take positive values, in the present invention, phenyl groups are not included in the electron-withdrawing groups.

Examples of electron-withdrawing groups include -F (σp: +0.20), -Cl (σp: +0.28), -Br (σp: +0.30), -I (σp: +0.30), -CO ₂ R ¹² (σp: +0.45 when R ¹² is an ethyl group), -CONH ₂ (σp: +0.38), -COR ¹² (σp: +0.49 when R ¹² is a methyl group), - Examples include CF ₃ (σp: +0.51), -SO ₂ R ¹² (σp: +0.69 when R ¹² is a methyl group), and -NO ₂ (σp: +0.81). R ¹² is each independently a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring atoms, or a substituted or unsubstituted heterocyclic group having 5 to 30 ring 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 each of these groups include the same examples as the substituents in the compound represented by general formula (2) or general formula (3) described below.

Among skeletons containing electron-withdrawing groups, skeletons containing heteroaryl groups having a partial structure in which carbon atoms and nitrogen atoms are bonded with double bonds, skeletons containing fluorinated substituents, skeletons containing cyano groups, A skeleton containing a carbonyl group, a skeleton containing a sulfoxide or disulfoxide, a skeleton containing a phosphine oxide group, etc. are preferred. Among these, skeletons containing heteroaryl groups with partial structures in which carbon atoms and nitrogen atoms are bonded by double bonds, skeletons containing fluorinated substituents, and skeletons containing cyano groups are suitable for delayed fluorescent materials. More preferred from the viewpoint of stability.

Among the skeletons containing a heteroaryl group having a partial structure in which a carbon atom and a nitrogen atom are bonded with a double bond, specific examples thereof include pyridine, pyrimidine, pyrazine, triazine, quinoline, quinoxaline, quinazoline, or phenanthroline. Skeletons are preferred. Among these, skeletons containing pyrimidine, triazine, quinoxaline, or quinazoline are more preferred, and skeletons containing triazine are even more preferred.

Among skeletons containing fluorinated substituents, skeletons containing fluorinated aryl groups or fluoroalkyl groups are more preferred. The skeleton containing a fluorinated aryl group is preferably a fluorinated benzene ring, and specifically, a skeleton containing fluorobenzene, difluorobenzene, trifluorobenzene, tetrafluorobenzene or pentafluorobenzene is more preferable. As the skeleton containing a fluoroalkyl group, a skeleton containing a benzene ring substituted with a trifluoromethyl group is preferable, and among these, a skeleton containing mono(trifluoromethyl)benzene or bis(trifluoromethyl)benzene is more preferable. .

Among skeletons having a cyano group, skeletons containing cyanobenzene, dicyanobenzene, and tricyanobenzene are more preferred.

An example of a compound in which the above-described electron donor skeleton and electron acceptor skeleton are combined is shown below, but the compound is not particularly limited to these. Note that the compounds shown here are known to emit delayed fluorescence according to past literature.

In addition to the above-mentioned compound in which an electron donor skeleton and an electron acceptor skeleton are combined as a delayed fluorescent material, a compound containing a partial structure represented by the following general formula (1) is preferable.

In general formula (1), B is a boron atom, N is a nitrogen atom, and C is a carbon atom. n is an integer from 0 to 2. When n is 0, the partial structure represented by general formula (1) represents a direct bond structure between B and N.

In a delayed fluorescent material containing a partial structure represented by the general formula (1), a nitrogen atom having an electron donor property and a boron atom having an electron acceptor property are arranged close to each other in the molecule. Such a delayed fluorescent material is a compound that can separate the HOMO orbital and the LUMO orbital due to the multiple resonance effect. By clearly separating the HOMO orbit and LUMO orbit of the delayed fluorescent material, the energy level of the singlet excited state and the energy level of the triplet excited state of the delayed fluorescent material can be brought closer to each other. This makes it easier to emit delayed fluorescence. In order to bring the energy level of the singlet excited state and the energy level of the triplet excited state closer together, the delayed fluorescent material contains two or more substructures represented by the general formula (1) in the molecule. Preferably, it is a compound.

Furthermore, in delayed fluorescent materials, when the π-conjugated system is expanded, reverse intersystem crossing occurs more efficiently from the triplet excited state to the singlet excited state. For this reason, it is preferable that the π-conjugated system of the delayed fluorescent material is expanded. From such a viewpoint, the delayed fluorescent material preferably contains a compound represented by the following general formula (2) or general formula (3).

In general formula (2) or general formula (3), ring Za, ring Zb and ring Zc each independently represent a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms, or a substituted or unsubstituted ring. It is a heteroaryl ring having 6 to 30 carbon atoms.

In general formula (2), Z ¹ and Z ² are each independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra), or a sulfur atom. When Z ¹ is NRa, the substituent Ra may be combined with ring Za or ring Zb to form a ring. When Z ² is NRa, the substituent Ra may be combined with ring Za or ring Zc to form a ring. E is a boron atom, a phosphorus atom, SiRa (silicon atom having a substituent Ra), or P=O.

In general formula (3), E ¹ and E ² each independently represent BRa (a boron atom having a substituent Ra), PRa (a phosphorus atom having a substituent Ra), and SiRa ₂ (a phosphorus atom having two substituents Ra). silicon atom), P(=O)Ra ₂ (phosphine oxide having two substituents Ra) or P(=S)Ra ₂ (phosphine sulfide having two substituents Ra), C=O (carbonyl group), S(=O) or S(=O) ₂ . When E ¹ is BRa, PRa, SiRa ₂ , P(=O)Ra ₂ or P(=S)Ra ₂ , the substituent Ra may be combined with ring Za or ring Zb to form a ring. . When ^E2 is BRa, PRa, _SiRa2 , P(=O) _Ra2 or P(=S) _Ra2 , the substituent Ra may be combined with ring Za or ring Zc to form a ring. .

The above substituents Ra each independently represent hydrogen, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or unsubstituted alkyl group, a substituted or unsubstituted cycloalkyl group, or a substituted or unsubstituted cycloalkyl group. Substituted heterocyclic group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkenyl group, substituted or unsubstituted alkynyl group, hydroxyl group, thiol group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted aryl ether group, substituted or unsubstituted arylthioether group, halogen, cyano group, aldehyde group, substituted or unsubstituted carbonyl group, substituted or unsubstituted carboxyl group, substituted or unsubstituted oxy Carbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted amide group, sulfonyl group, substituted or unsubstituted sulfonic acid ester group, substituted or unsubstituted sulfonamide group, substitution or unsubstituted amino group, substituted or unsubstituted imino group, nitro group, substituted or unsubstituted silyl group, substituted or unsubstituted siloxanyl group, substituted or unsubstituted boryl group, substituted or unsubstituted phosphine oxide group , and a fused ring and an aliphatic ring formed between adjacent substituents. Moreover, the substituent Ra may be further substituted with a substituent selected from these. The substituent substituting the substituent Ra may be further substituted with a substituent selected from these.

Furthermore, the compound represented by this general formula (2) or general formula (3) preferably contains two or more partial structures represented by the above-mentioned general formula (1) in the molecule.

In all of the above groups, hydrogen may be deuterium. This also applies to the compounds or partial structures thereof described below. In addition, in this specification, for example, a substituted or unsubstituted aryl group having 6 to 40 carbon atoms refers to an aryl group having 6 to 40 carbon atoms, including the number of carbon atoms contained in the substituents substituted on the aryl group. It is. The same applies to other substituents defining the number of carbon atoms.

In the case of "substituted or unsubstituted", "unsubstituted" means that a hydrogen atom or a deuterium atom is substituted. In the compounds or partial structures thereof described below, the term "substituted or unsubstituted" is the same as above.

In addition, in all of the above groups, substituents when substituted include alkyl groups, cycloalkyl groups, heterocyclic groups, alkenyl groups, cycloalkenyl groups, alkynyl groups, aryl groups, heteroaryl groups, hydroxyl groups, and thiol groups. group, alkoxy group, alkylthio group, aryl ether group, arylthioether group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, oxycarbonyl group, amide group, sulfonyl group, sulfonic acid ester group, sulfonamide group, amino group, nitro group, silyl group, siloxanyl group, boryl group, or phosphine oxide group. Moreover, these substituents may be further substituted with the above-mentioned substituents.

The alkyl group refers to a saturated aliphatic hydrocarbon group 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; It may or may not have a group. There are no particular restrictions on the additional substituents when substituted, and examples thereof include alkyl groups, halogens, aryl groups, heteroaryl groups, and the like, and this point is also common to the following description. Further, the number of carbon atoms in the alkyl group is not particularly limited, but from the viewpoint of availability and cost, it is preferably in the range of 1 to 20, more preferably 1 to 8.

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

A heterocyclic group refers to an aliphatic ring having an atom other than carbon in the ring, such as a pyran ring, a piperidine ring, or a cyclic amide, whether or not it has a substituent. good. The number of carbon atoms in the heterocyclic group is not particularly limited, but is preferably in the range of 2 or more and 20 or less.

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

A cycloalkenyl group refers to an unsaturated alicyclic hydrocarbon group containing a double bond, such as a cyclopentenyl group, a cyclopentadienyl group, or a cyclohexenyl group, even if it has a substituent. It is not necessary to have it. The number of carbon atoms in the cycloalkenyl group is not particularly limited, but is preferably in the range of 3 or more and 20 or less.

The alkynyl group refers to, 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 in the alkynyl group is not particularly limited, but is preferably in the range of 2 or more and 20 or less.

An alkoxy group refers to a functional group to which an aliphatic hydrocarbon group is bonded via an ether bond, such as a methoxy group, an ethoxy group, or a propoxy group, and this aliphatic hydrocarbon group has a substituent. It is not necessary to have either. The number of carbon atoms in the alkoxy group is not particularly limited, but is preferably in the range of 1 to 20.

An alkylthio group is an alkoxy group in which the oxygen atom of the ether bond is replaced with a sulfur atom. The hydrocarbon group of the alkylthio group may or may not have a substituent. The number of carbon atoms in the alkylthio group is not particularly limited, but is preferably in the range of 1 to 20.

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

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

Aryl groups include, for example, phenyl group, biphenyl group, terphenyl group, naphthyl group, fluorenyl group, benzofluorenyl group, dibenzofluorenyl group, phenanthryl group, anthracenyl group, benzophenanthryl group, and benzanthracetyl group. This refers to aromatic hydrocarbon groups such as nyl group, chrysenyl group, pyrenyl group, fluoranthenyl group, triphenylenyl group, benzofluoranthenyl group, dibenzaanthracenyl group, perylenyl group, and helicenyl group. Among these, phenyl group, biphenyl group, terphenyl group, naphthyl group, fluorenyl group, phenanthryl group, anthracenyl group, pyrenyl group, fluoranthenyl group, and triphenylenyl group are preferable. The aryl group may or may not have a substituent. The number of carbon atoms in the aryl group is not particularly limited, but is preferably in the range of 6 or more and 40 or less, more preferably 6 or more and 30 or less.

Further, 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, and a phenyl group, a biphenyl group, a terphenyl group, and a naphthyl group are more preferable. More preferred are phenyl, biphenyl, and terphenyl, with phenyl being 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, or an anthracenyl group; More preferred are phenyl group and naphthyl group. Particularly preferred is a phenyl group.

Examples of heteroaryl groups include 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 group, benzothienyl group, indolyl group, dibenzofuranyl group, dibenzothienyl group, carbazolyl group, benzocarbazolyl group, carbolinyl group, indolocarbazolyl group, benzofurocarbazolyl group, benzothienocarbazolyl Atoms other than carbon, such as groups, dihydroindenocarbazolyl groups, benzoquinolinyl groups, acridinyl groups, dibenzaacridinyl groups, benzimidazolyl groups, imidazopyridyl groups, benzoxazolyl groups, benzothiazolyl groups, phenanthrolinyl groups, etc. represents a cyclic aromatic group having one or more in the ring. However, the naphthyridinyl group refers to any of the following: 1,5-naphthyridinyl group, 1,6-naphthyridinyl group, 1,7-naphthyridinyl group, 1,8-naphthyridinyl group, 2,6-naphthyridinyl group, 2,7-naphthyridinyl group. Show that. A heteroaryl group may or may not have a substituent. The number of carbon atoms in the heteroaryl group is not particularly limited, but is preferably in the range of 2 or more and 40 or less, more preferably 2 or more and 30 or less.

In addition, examples of the heteroaryl group include a pyridyl group, a furanyl group, a thienyl group, a quinolinyl group, a pyrimidyl group, a triazinyl group, a benzofuranyl group, a benzothienyl group, an indolyl group, a dibenzofuranyl group, a dibenzothienyl group, a carbazolyl group, and a benzimidazolyl group. , imidazopyridyl group, benzoxazolyl group, benzothiazolyl group, and phenanthrolinyl group are preferable, and pyridyl group, furanyl group, thienyl group, and quinolinyl group are more preferable. Particularly preferred is a pyridyl group.

When each substituent is further substituted with a heteroaryl group, examples of the heteroaryl group include pyridyl group, furanyl group, thienyl group, quinolinyl group, pyrimidyl group, triazinyl group, benzofuranyl group, benzothienyl group, indolyl group, dibenzo 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 refers to an atom selected from fluorine, chlorine, bromine, and iodine. Furthermore, the carbonyl group, carboxyl group, oxycarbonyl 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 these substituents may be further substituted.

The 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 straight-chain alkyl group, and a branched alkyl group. As the aryl group and heteroaryl group, phenyl group, naphthyl group, pyridyl group, and quinolinyl group are preferable. These substituents may be further substituted. The number of carbon atoms is not particularly limited, but is preferably in the range of 2 or more and 50 or less, more preferably 6 or more and 40 or less, particularly preferably 6 or more and 30 or less.

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

The siloxanyl group refers to a silicon compound group via an ether bond, such as a trimethylsiloxanyl group. Substituents on silicon may be further substituted. Moreover, 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 straight-chain alkyl group, a branched alkyl group, an aryl ether group, an alkoxy group, and a hydroxyl group. Among these, aryl groups and aryl ether groups are preferred.

The phosphine oxide group is a group represented by -P(=O)R ¹⁰ R ¹¹ . R ¹⁰ R ¹¹ of the phosphine oxide group is selected from the same group as the above-mentioned substituents.

Examples of the substituted or unsubstituted aryl ring having 6 to 30 carbon atoms in Ring Za, Ring Zb, and Ring Zc include aromatic hydrocarbon rings such as a benzene ring, a naphthalene ring, a phenanthrene ring, a chrysene ring, an anthracene ring, and a pyrene ring. can be mentioned. Among these, a benzene ring is preferred from the viewpoint of ensuring solubility. Examples of the heteroaryl ring having 6 to 30 carbon atoms include aromatic heteroaryl ring structures such as a pyridine ring, a quinoline ring, and a phenanthroline ring. Among these, a pyridine ring is preferred from the viewpoint of raw material availability and synthesis difficulty.

In general formula (2), the substituent Ra is preferably a group having 6 to 40 carbon atoms including the substituents. The substituent Ra is more preferably a substituted or unsubstituted aryl group. Examples of the substituted or unsubstituted aryl group include a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted fluorenyl group, a substituted or unsubstituted naphthyl group, a substituted or unsubstituted phenanthrenyl group, etc. can be mentioned. Among these, substituted or unsubstituted phenyl groups are more preferred.

Furthermore, in the general formula (3), the substituent Ra is preferably a group having 6 to 40 carbon atoms including the substituents. The substituent Ra is more preferably a substituted or unsubstituted aryl group or a substituted or unsubstituted alkyl group.

Z ¹ and Z ² in general formula (2) are preferably an oxygen atom or NRa. This is because the π-conjugated system of the compound represented by general formula (2) expands efficiently, and reverse intersystem crossing occurs more efficiently from the triplet excited state to the singlet excited state, further improving durability. This is because it can be done.

Further, E in general formula (2) is preferably a boron atom, and E ¹ and E ² in general formula (3) are preferably BRa. This is because the π-conjugated system of the compound represented by general formula (2) or general formula (3) expands efficiently, and reverse intersystem crossing occurs more efficiently from the triplet excited state to the singlet excited state. This is because the durability can be further improved.

Further, it is preferable that the ring Za, the ring Zb, and the ring Zc are benzene rings. This is because the π-conjugated system of the compound represented by general formula (2) or general formula (3) expands efficiently, and reverse intersystem crossing occurs more efficiently from the triplet excited state to the singlet excited state. This is because the durability can be further improved.

The compound represented by the general formula (2) or the general formula (3) is described, for example, in the literature Adv. Mater. , 2016, 28, 2777-2781, by optimally arranging the electron donating amine nitrogen atom and the electron acceptor boron atom, the HOMO orbital and LUMO orbital can be separated by the multiple resonance effect. It is a molecule that can be separated. From the viewpoint of clearly separating the HOMO orbital and the LUMO orbital and bringing the singlet excited state and triplet excited state closer together to facilitate the emission of delayed fluorescence, in general formula (2), E is an electron acceptor. NRa is preferably a boron atom with strong electron donor properties, and Z ¹ and Z ² are both groups with strong electron donor properties.

Furthermore, the emission spectrum of the compound represented by general formula (2) or general formula (3) is sharper than that of a compound in which an electron donor skeleton and an electron acceptor skeleton are combined, due to the multiple resonance effect of the compound. Become. Therefore, when the delayed fluorescent material is a compound represented by the general formula (2) or the general formula (3), light emission with high color purity can be obtained. That is, the compound represented by the general formula (2) or the general formula (3) is advantageous in improving the color gamut of a display, and is therefore preferable as a delayed fluorescent material. In addition, the compound represented by the general formula (2) or the general formula (3) mainly has a ring Za or a ring around the E atom in the general formula (2) or the general formula (3) where the LUMO orbital is localized. Since Zb and ring Zc exist, the LUMO orbital can be delocalized from the E atom to each ring. By delocalizing the LUMO orbital, the multiple resonance effect works efficiently, so that luminescence with higher color purity can be obtained. Note that the above E atom is an atom of E in general formula (2), and is each atom of E ¹ and E ² in general formula (3).

Furthermore, it is more preferable that the substituent Ra of the general formula (2) or the general formula (3) forms a structure bonded to at least one ring of the ring Za, the ring Zb, and the ring Zc. This is because substituent Ra is bonded to at least one ring of ring Za, ring Zb, and ring Zc, so that E in general formula (2) and E ¹ and E ² in general formula This is because it is expected that the protective effect will be further enhanced and the effect of suppressing the decrease in fluorescence quantum yield will be further improved.

Examples of compounds represented by general formula (2) or general formula (3) are shown below. However, the compounds are not particularly limited to these.

The emission wavelength of the delayed fluorescent material is not particularly limited, but in order to extract the three primary colors of blue, green, and red from a blue light source, the delayed fluorescent material has a green or red emission wavelength when excited with blue light. It is preferable that there be. That is, the delayed fluorescent material exhibits luminescence observed in a region with a peak wavelength of 500 nm or more and less than 580 nm by using excitation light with a wavelength of 400 nm or more and 500 nm or less, or when excitation light with a wavelength of 400 nm or more and 500 nm or less is observed. It is preferable to use light to emit light whose peak wavelength is observed in a region of 580 nm or more and 750 nm or less.

Furthermore, in order to expand the color gamut and improve color reproducibility, it is preferable that the emission spectra of blue, green, and red have small overlap.

For example, when blue light having a wavelength of 400 nm or more and 500 nm or less and having appropriate excitation energy is used as excitation light, light emission observed in a region with a peak wavelength of 500 nm or more is used as green light emission. In this case, the overlap between the emission spectra of the excitation light and the green light is reduced, and color reproducibility is improved, which is preferable. In order to further increase the effect, the lower limit of the peak wavelength of light emission when the light emitting material according to the embodiment of the present invention emits green light is more preferably 510 nm or more, and even more preferably 515 nm or more. The wavelength is particularly preferably 520 nm or more.

Furthermore, in order to reduce the overlap between the emission spectra of excitation light and red light, it is preferable to use light emission observed in a region with a peak wavelength of less than 580 nm as green light emission. In order to further increase the effect, the upper limit of the peak wavelength of light emission when the light emitting material according to the embodiment of the present invention emits green light is more preferably 550 nm or less, and even more preferably 540 nm or less. The wavelength is particularly preferably 535 nm or less.

Furthermore, when using the light emission observed in a region with a peak wavelength of 500 nm or more and less than 580 nm as green light emission, the light emission observed in a region with a peak wavelength of 580 nm or more is used as red light emission. In this case, the overlap between the emission spectra of green light and red light is reduced and color reproducibility is improved, which is preferable. In order to further increase the effect, when the luminescent material according to the embodiment of the present invention emits red light, the lower limit of the peak wavelength of light emission is more preferably 620 nm or more, and even more preferably 630 nm or more. The wavelength is particularly preferably 635 nm or more.

The upper limit of the peak wavelength of red light may be 750 nm or less, which is near the upper limit of the visible range, but 700 nm or less is more preferable because visibility increases. In order to further increase the effect, the upper limit of the peak wavelength when the luminescent material according to the embodiment of the present invention emits red light is more preferably 680 nm or less, particularly preferably 660 nm or less.

That is, when blue light having a wavelength of 400 nm or more and 500 nm or less is used as excitation light, the peak wavelength of the green light is preferably 500 nm or more and less than 580 nm, more preferably 510 nm or more and 550 nm or less, and 515 nm or more and 540 nm or less. It is more preferably the following, and particularly preferably 520 nm or more and 530 nm or less. Further, the peak wavelength of the red light is preferably 580 nm or more and 750 nm or less, more preferably 620 nm or more and 700 nm or less, even more preferably 630 nm or more and 680 nm or less, and particularly preferably 635 nm or more and 660 nm or less. preferable.

In addition, in order to reduce the overlap of emission spectra and improve color reproducibility, it is necessary to increase the half-width at the peak wavelength of the emission spectra of each color of blue, green, and red (hereinafter simply referred to as "half-width of emission spectrum"). Preferably small. In particular, a small half-width of each emission spectrum of green light and red light is effective for improving color reproducibility.

For example, the half width of the emission spectrum of green light is preferably 50 nm or less, more preferably 40 nm or less, even more preferably 30 nm or less, and particularly preferably 25 nm or less. The half width of the emission spectrum of red light is preferably 80 nm or less, more preferably 60 nm or less, even more preferably 50 nm or less, and particularly preferably 40 nm or less.

The delayed fluorescent material included in the particulate color conversion material according to the embodiment of the present invention emits delayed fluorescence with a half width of 50 nm or less, and therefore can achieve high color reproducibility. "Emits delayed fluorescence with a half-value width of 50 nm or less" means that the half-value width of the emission spectrum of the delayed fluorescent material is 50 nm or less. The half width of the emission spectrum of the delayed fluorescent material in the present invention is more preferably 40 nm or less, even more preferably 30 nm or less, and particularly preferably 25 nm or less.

Note that the shape of the emission spectrum of the delayed fluorescent material in the present invention is not particularly limited. For example, it is preferable that the emission spectrum of the delayed fluorescent material in the present invention has a single peak because it allows efficient use of excitation energy and increases color purity. Here, a single peak refers to a state in which there is no peak having an intensity of 5% or more of the strongest peak in a certain wavelength region.

Furthermore, when the organic light-emitting material emits green light, this organic light-emitting material passes through an excited state with higher energy than when it emits red light. For this reason, organic light-emitting materials that emit green light (hereinafter sometimes abbreviated as green light-emitting materials) are inherently more prone to deterioration than organic light-emitting materials that emit red light. On the other hand, organic light-emitting materials that emit delayed fluorescence, especially delayed fluorescence materials containing compounds represented by general formula (2) or general formula (3), achieve both high color purity of light emission and high durability. can be done. Therefore, in order to further improve the durability of the color conversion member, at least the green light emitting material (first light emitting material) among the one or more types of light emitting materials contained in the particulate color conversion material should emit delayed fluorescence. Preferably, it is an organic luminescent material. That is, the delayed fluorescent material preferably emits light whose peak wavelength is observed in a region of 500 nm or more and less than 580 nm by using excitation light with a wavelength of 400 nm or more and 500 nm or less.

<Other luminescent materials>
The particulate color conversion material according to the embodiment of the present invention includes, as at least one luminescent material contained in the matrix resin, in addition to the delayed fluorescent material described above, a material other than an organic luminescent material that emits delayed fluorescence. It can have a luminescent material (or other luminescent material). Examples of the other luminescent materials include inorganic phosphors, fluorescent pigments, fluorescent dyes, quantum dots, and organic luminescent materials that do not emit delayed fluorescence. The other luminescent material may contain two or more of these. In order to achieve highly efficient color conversion, the other luminescent material is preferably a material that exhibits luminescent properties with high quantum yield. Specifically, quantum dots and organic light-emitting materials that do not emit delayed fluorescence are preferred, and organic light-emitting materials that do not emit delayed fluorescence are particularly preferred.

Suitable organic light-emitting materials that do not emit delayed fluorescence include, for example, compounds having a fused aryl ring such as naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, and indene, and derivatives thereof. It is mentioned as.

Examples of organic light-emitting materials that do not emit delayed fluorescence include furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, Suitable examples include compounds having a heteroaryl ring such as imidazopyridine, phenanthroline, pyridine, pyrazine, naphthyridine, quinoxaline, and pyrrolopyridine, and derivatives thereof.

Examples of organic light-emitting materials that do not emit delayed fluorescence include borane derivatives, stilbene derivatives, aromatic acetylene derivatives, tetraphenylbutadiene derivatives, aldazine derivatives, pyrromethene derivatives, diketopyrrolo[3,4-c]pyrrole derivatives, and coumarin derivatives. etc. are mentioned as suitable ones. Examples of stilbene derivatives include 1,4-distyrylbenzene, 4,4'-bis(2-(4-diphenylaminophenyl)ethenyl)biphenyl, 4,4'-bis(N-(stilben-4-yl) )-N-phenylamino)stilbene and the like. Examples of coumarin derivatives include coumarin 6, coumarin 7, coumarin 153, and the like.

Suitable organic light-emitting materials that do not emit delayed fluorescence include azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole, and triazole, and metal complexes thereof.

Furthermore, suitable examples of organic light-emitting materials that do not emit delayed fluorescence include cyanine compounds, xanthene compounds, and thioxanthene compounds. Examples of cyanine compounds include indocyanine green and the like. Examples of xanthene compounds and thioxanthene compounds include fluorescein, eosin, rhodamine, and the like.

In addition, suitable examples of organic light-emitting materials that do not emit delayed fluorescence include polyphenylene compounds, naphthalimide derivatives, phthalocyanine derivatives and their metal complexes, porphyrin derivatives and their metal complexes, oxazine compounds, helicene compounds, etc. Can be mentioned. Examples of oxazine compounds include Nile Red and Nile Blue.

In addition, suitable examples of organic light-emitting materials that do not emit delayed fluorescence include aromatic amine derivatives and organometallic complex compounds. Examples of aromatic amine derivatives include N,N'-diphenyl-N,N'-di(3-methylphenyl)-4,4'-diphenyl-1,1'-diamine. Examples of the organometallic complex compound include iridium (Ir), ruthenium (Ru), rhodium (Rh), palladium (Pd), platinum (Pt), osmium (Os), and rhenium (Re).

An example of the organic light-emitting material as described above is shown below, but the organic light-emitting material is not particularly limited to these.

Further, as an organic light-emitting material that does not emit delayed fluorescence, one containing a partial structure represented by the above-mentioned general formula (1) is also preferable from the viewpoint of obtaining light emission with high color purity.

The above-mentioned organic light-emitting material that does not emit delayed fluorescence may be a fluorescent material or a phosphorescent material, but in order to achieve high color purity, it is preferably a fluorescent material. Among them, pyrromethene derivatives can be preferably used because they provide a high fluorescence quantum yield and have better chromaticity durability. Among the pyrromethene derivatives, boron complexes of pyrromethene are preferred. Preferred examples of the boron complex of pyrromethene include compounds represented by the general formula (4) described below.

Furthermore, the particulate color conversion material according to the embodiment of the present invention may further contain an assist dopant such as rubrene in order to increase the efficiency of energy transfer from excitation light to the delayed fluorescent material.

The content of the luminescent material in the particulate color conversion material of the present invention is determined by the molar extinction coefficient of the compound, the emission quantum yield, the absorption intensity at the excitation wavelength, and the size and thickness of the particulate color conversion material or color conversion member to be produced. Although it depends on the transmittance, it is usually preferably 1.0 x 10 ^-4 parts by weight or more and 30 parts by weight or less per 100 parts by weight of the matrix resin. Further, the content of the luminescent material is more preferably 1.0 x 10 ^-3 parts by weight or more and 10 parts by weight or less, particularly preferably 5.0 x 10 ^-3 parts by weight or more and 5 parts by weight or less. preferable.

<Matrix resin>
A particulate color conversion material according to an embodiment of the present invention includes a matrix resin containing at least one type of luminescent material described above. In the particulate color conversion material, a material having excellent moldability, transparency, heat resistance, etc. is preferably used as the matrix resin. Examples of such matrix resins include photocurable resist materials having reactive vinyl groups such as acrylic acid, methacrylic acid, polyvinyl cinnamate, and ring rubber, epoxy resins, and silicone resins. rubber, silicone gel, etc.), urea resin, fluororesin, polycarbonate resin, acrylic resin, urethane resin, melamine resin, polyvinyl resin, polyamide resin, phenol resin, polyvinyl alcohol resin, Known resins include cellulose resin, aliphatic ester resin, aromatic ester resin, aliphatic polyolefin resin, and aromatic polyolefin resin. Furthermore, as the matrix resin, a mixture or copolymer of these resins may be used. By appropriately designing these resins, a matrix resin useful for the particulate color conversion material of the color conversion member of the present invention can be obtained.

Among these resins, from the viewpoint of transparency and dispersibility of organic light emitting materials, the above matrix resins include acrylic resins, copolymer resins containing acrylic ester or methacrylic ester moieties, polyester resins, cycloolefin resins, and epoxy resins. , silicone resin. Moreover, from the viewpoint of heat resistance, a thermosetting resin or a photocurable resin can be suitably used as the matrix resin.

Furthermore, the glass transition temperature (Tg) of the matrix resin is not particularly limited, but is preferably 30° C. or higher and 180° C. or lower. When the Tg of the matrix resin is 30°C or higher, the molecular movement of the matrix resin due to the heat from the incident light from the light source or the driving heat of the equipment is suppressed, and thereby the change in the dispersion state of the luminescent material in the matrix resin is suppressed. Since this is suppressed, deterioration of the durability of the particulate color conversion material can be prevented. Further, when the Tg of the matrix resin is 180° C. or less, the flexibility of the matrix resin when molded into a sheet or the like can be ensured. The Tg of the matrix resin is more preferably 50°C or more and 170°C or less, still more preferably 70°C or more and 160°C or less, particularly preferably 90°C or more and 150°C or less.

Furthermore, the molecular weight of the matrix resin is not particularly limited as it depends on the type of resin used, but it is preferably 3,000 or more and 1,500,000 or less. When the molecular weight is smaller than 3000, the matrix resin becomes brittle and the flexibility of the matrix resin when molded becomes low. Furthermore, if the molecular weight is greater than 1,500,000, there are problems such as the viscosity of the matrix resin during molding becoming excessively large and the chemical stability of the matrix resin itself decreasing. The molecular weight of the matrix resin is more preferably 5,000 or more and 1,200,000 or less, still more preferably 7,000 or more and 1,000,000 or less, particularly preferably 10,000 or more and 800,000 or less.

<Additives>
The particulate color conversion material according to the embodiment of the present invention may contain additives as other components in addition to the above-mentioned at least one luminescent material and matrix resin. Examples of additives include light stabilizers, antioxidants, processing and heat stabilizers, light resistance stabilizers such as ultraviolet absorbers, plasticizers, crosslinking agents such as epoxy compounds, amines, acid anhydrides, Examples include curing agents such as imidazole, inorganic particles such as silica particles and silicone fine particles, and silane coupling agents.

Examples of the light stabilizer include tertiary amines, catechol derivatives, Ni, Sc, V, Mn, Fe, Co, Cu, Y, Zr, Mo, Ag, and at least one type of transition selected from the group consisting of lanthanoids. Examples include complexes containing metals and salts with organic acids, but are not particularly limited. Further, these light stabilizers may be used alone or in combination.

Examples of antioxidants include phenolic antioxidants such as 2,6-di-tert-butyl-p-cresol and 2,6-di-tert-butyl-4-ethylphenol. It is not particularly limited to these. Further, these antioxidants may be used alone or in combination.

Examples of processing and thermal stabilizers include, but are not limited to, phosphorus stabilizers such as tributyl phosphite, tricyclohexyl phosphite, triethyl phosphine, and diphenylbutyl phosphine. Further, these stabilizers may be used alone or in combination.

Examples of light resistance stabilizers include 2-(5-methyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H- Examples include benzotriazoles such as benzotriazole, but are not particularly limited thereto. Further, these light resistance stabilizers may be used alone or in combination.

As the scattering particles, for example, inorganic particles having a refractive index of 1.7 or more and 2.8 or less are preferable. Examples of the inorganic particles include titania, zirconia, alumina, ceria, tin oxide, indium oxide, iron oxide, zinc oxide, aluminum nitride, aluminum, tin, titanium or zirconium sulfide, titanium or zirconium hydroxide, etc. can be mentioned.

In the particulate color conversion material according to the embodiment of the present invention, the content of these additives is determined based on the molar absorption coefficient of the compound, the emission quantum yield, and the absorption intensity at the excitation wavelength, as well as the particulate color conversion material to be produced and the content of these additives. Although it depends on the size, thickness, and transmittance of the color conversion member, it is preferably 1.0 x 10 ^-3 parts by weight or more, and 1.0 x 10 ^-2 parts by weight based on 100 parts by weight of the matrix resin. The amount is more preferably at least 1.0×10 ⁻¹ parts by weight, particularly preferably at least 1.0×10 −1 parts by weight. Further, the content of these additives is preferably 30 parts by weight or less, more preferably 15 parts by weight or less, and preferably 10 parts by weight or less with respect to 100 parts by weight of the matrix resin. Particularly preferred.

<Particulate color conversion material>
As described above, the particulate color conversion material of the present invention is a particulate color conversion material containing at least one type of luminescent material in a matrix resin, and can be handled as a powder. Therefore, by mixing and using a plurality of types of particulate color conversion materials, it is easy to precisely adjust wavelength conversion characteristics. For example, when color converting a part of blue light to obtain white light, the particulate color conversion material contains a green conversion material containing a luminescent material that emits green light and a luminescent material that emits red light. The white balance and color temperature of white light can be easily adjusted by preparing a red color converting material and adjusting the amount of mixture thereof.

Furthermore, by controlling the particle size and shape of the particulate color conversion material, the refractive index of the matrix resin, etc., the color conversion characteristics of the particulate color conversion material can be adjusted, and functions other than the color conversion function can be added to the particulate color conversion material. It is also possible to give. For example, it is possible to develop a light scattering function.

In the particulate color conversion material of the present invention, each particle of the color conversion material is individually independent. Therefore, when highly active species such as radicals are generated in a particle group of particulate color conversion material or a color conversion member using particulate color conversion material due to light irradiation under high temperature conditions, highly active species such as radicals are generated. Propagation to the entire particle group is suppressed. Thereby, accelerated deterioration of the particle group of the particulate color conversion material or the entire color conversion member using the particulate color conversion material can be suppressed.

Furthermore, in the particulate color conversion material of the present invention, at least the above-mentioned delayed fluorescent material is used as one or more types of luminescent material contained in the matrix resin. Therefore, it is possible to further improve the durability of the particulate color conversion material and the color conversion member using the same, and to achieve high color purity and high durability of the particulate color conversion material and the color conversion member using the same. It is possible to achieve both. In general, particulate color conversion materials and color conversion members using them have more interfaces than continuous phase materials such as films, so the number of excitations of the luminescent material tends to increase due to reflection at the interfaces. . This is because a part of the light emitted from the luminescent material contained in the particulate color conversion material is reflected at the interface between the inside and outside of the particle of the particulate color conversion material, re-exciting the luminescent material inside the particle. happen. This increase in the number of excitations is due to an increase in the number of organic light-emitting materials in the triplet excited state, and to highly active chemicals such as singlet oxygen generated due to energy transfer from the organic light-emitting material in the triplet excited state. This leads to an increase in the probability of species generation and an increase in the chance that these active species react with surrounding molecules, thus promoting the deterioration and decomposition of the organic light-emitting material in the particulate color conversion material. On the other hand, delayed fluorescent materials, as mentioned above, can quickly convert the triplet excited state to the singlet excited state, so they do not deteriorate easily even if the number of excitations increases due to reflection at the interface, making them an excellent material. It can show durability.

The average particle size of the particulate color conversion material of the present invention is preferably 0.0010 μm or more and 100 μm or less, more preferably 0.010 μm or more and 30 μm or less, and especially 0.010 μm or more and 10 μm or less. preferable. The average particle diameter of the particulate color conversion material is obtained by measuring the particle size distribution by microscopic observation or laser diffraction scattering method, but in principle, it is obtained from the measurement results of the particle size distribution by microscopic observation. However, if a particle size of 1 μm or less is obtained from the measurement results of the particle size distribution by the laser diffraction scattering method, the particle size determined by the laser diffraction scattering method is used as the average particle size of the particulate color conversion material. In addition, in the case of measuring the particle size distribution by microscopic observation, for example, the particle size of about 100 isolated particles among the powder of the particulate color conversion material is measured, and the average value thereof is calculated. , the average particle size of the particulate color conversion material can be determined.

The shape of the particulate color conversion material of the present invention is not particularly limited, and may be spherical, for example, as in the particulate color conversion materials 2a and 2b shown in FIGS. 1 to 7 above. , or may have a shape other than a spherical shape, such as an ellipsoidal shape. Among these, the shape of the particulate color conversion material of the present invention is preferably a shape with high sphericity. The high sphericity of the particulate color conversion material makes it possible to reduce optical loss due to undesired light scattering on the surface of the particles of the particulate color conversion material and multiple reflections inside the particles. Furthermore, it is possible to suppress accelerated deterioration of a luminescent material (for example, an organic luminescent material in a particulate color conversion material) due to multiple excitation.

<Method for producing particulate color conversion material>
The method for producing the particulate color conversion material according to the embodiment of the present invention is not particularly limited as long as it is a method that can mold a matrix resin containing at least one type of luminescent material into particles. For example, particulate color conversion materials can be produced by interfacial polymerization, W/O drying in liquid, Stover method, spray drying, in situ polymerization, phase separation from aqueous solutions, phase separation from organic solvents, and melting. It can be produced by methods such as a dispersion cooling method and an air suspension coating method.

Among them, a method of forming particles into particles by drying a composition prepared by mixing predetermined amounts of materials such as the above-mentioned luminescent material, matrix resin, and solvent using a spray drying method is a simple method for producing particulate color conversion materials. This can be mentioned as a manufacturing method. From the viewpoint that the shape of the obtained particles approaches a perfect sphere, a composition prepared by mixing predetermined amounts of materials such as the luminescent material, matrix resin, and organic solvent described above is made into a W/O emulsion, and then a W/O emulsion is formed. A composition prepared by mixing predetermined amounts of materials such as a luminescent material, a raw material monomer for forming a matrix resin, a solvent, etc., and a method of forming particles by drying in a system liquid, or an in-situ method. A preferred method for producing a particulate color conversion material is a polymerization method, in particular, a method in which the particulate color conversion material is formed into particles by polymerization by an emulsion polymerization method in which a W/O emulsion is reacted using a surfactant.

In addition, when the particulate color conversion material is produced by a W/O-based in-liquid drying method, either the W/O emulsion state of the above composition or the fine particle state during or after the removal of the organic solvent from the above composition. A method of improving the heat resistance of the particles by additionally crosslinking and curing the matrix resin at this stage can also be cited as a suitable method for producing the particulate color conversion material.

Examples of the solvent include 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, Examples include 2-dimethoxyethane, methyl cellosolve, ethyl cellosolve, butyl carbitol, butyl carbitol acetate, 1-methoxy-2-propanol, propylene glycol monomethyl ether acetate, and the like. It is also possible to use a mixture of two or more of these solvents. Among these solvents, toluene, methyl ethyl ketone, methyl acetate, ethyl acetate, and tetrahydrofuran are preferably used because they leave little solvent remaining after drying.

<Support>
The particulate color conversion material of the invention may be used as such (ie in the form of particles). Further, from the viewpoint of further enhancing applicability to optical members, the particulate color conversion material of the present invention is preferably used in a state in which it is contained in a support. A support containing the particulate color conversion material of the present invention can be used as a color conversion member of the present invention, for example, as shown in FIGS. 1 to 7.

As the material of the support, known metals, resins, glass, ceramics, paper, etc. can be used without particular limitations, but from the viewpoint of transparency and processability, it is preferable that the support is made of resin. . When the support is made of resin, it is more preferable that the particulate color conversion material is dispersed in the support. In the present invention, dispersion refers to the scattering of other substances in a substance forming one phase, and the distribution may be biased or uniform. However, when it is stated that the particulate color conversion material is dispersed, this excludes an embodiment in which it is completely dissolved in a dispersion medium to form one uniform phase. In order to confirm whether the particulate color conversion material of the present invention is dispersed in the support, methods such as visual observation, microscopic observation, emission spectroscopy measurement, and refractive index measurement can be used as appropriate. Examples of resins suitable for the support include the resins exemplified in the above-mentioned matrix resins.

Further, when the support is made of resin, the difference in SP value between the matrix resin of the particulate color conversion material and the resin forming the support is preferably ^0.5 (cal/cm ³ ) or more. When the difference in SP value is ^0.5 (cal/cm ³ ) or more, the particulate color conversion material can be dispersed in the support without being dissolved. The difference in SP value is more preferably 1.0 (cal/cm ³ ) ^0.5 or more, more preferably 1.5 (cal/cm ³ ) ^0.5 or more, and 2.0 (cal/cm 3 ) ³ ) It is particularly preferable that it is ^0.5 or more. Furthermore, if the difference in SP value is too large, particles will aggregate with each other, causing quenching. Therefore, the upper limit of the difference in SP values is more preferably 4.0 (cal/cm ³ ) ^0.5 or less, even more preferably 3.0 (cal/cm ³ ) ^0.5 or less, 2.5 (cal/cm ³ ) ^0.5 or less is particularly preferable.

Furthermore, when the support is made of resin, the SP value of the matrix resin of the particulate color conversion material is preferably larger than the SP value of the resin forming the support.

The nature of the support is not particularly limited, but includes liquid, gel, and solid states. The shape of the support is not particularly limited, but examples include granules, blocks, and sheets. Further, the shape of the support includes a type filled in a mold. Among these, from the viewpoint of further increasing applicability to a light source unit described below, the shape of the support is preferably a sheet.

On the other hand, from the viewpoint of integration with an LED light source or with a patterned member, a method of filling a mold is also preferable as a method of forming the support.

The number of particulate color conversion materials contained in the support as described above may be one or more types.

In one embodiment, the color conversion member of the present invention includes a particulate color conversion material (hereinafter referred to as a first particulate color conversion material) containing a first luminescent material (green luminescent material) that emits green light; It is preferable that the same support contains at least two types of particulate color conversion material (hereinafter referred to as second particulate color conversion material) containing a second light emitting material (red light emitting material) that emits light of . Thereby, the color conversion member of the present invention can convert a part of blue light into white light.

That is, the color conversion member of the present invention includes the above-described particulate color conversion material and a support, and the particulate color conversion material includes a first light emission whose peak wavelength is observed in a region of 500 nm or more and less than 580 nm. A first particulate color conversion material made of a material and a first matrix resin, and a second particulate color conversion material made of a second matrix resin and a second luminescent material that emits light whose peak wavelength is observed in a region of 580 nm or more and 750 nm or less. A color converting material is preferably contained in the above-mentioned support.

In the present invention, it is more preferable that the first luminescent material of the first particulate color conversion material includes at least an organic luminescent material (delayed fluorescent material) that emits delayed fluorescence with a half width of 50 nm or less. As mentioned above, the durability of the color conversion member can be improved by using the green light-emitting material that passes through an excited state with high energy (i.e., the first light-emitting material) containing the delayed fluorescent material or being the delayed fluorescent material itself. Further improvements can be made.

On the other hand, in the present invention, the second luminescent material of the second particulate color conversion material is a compound containing a partial structure represented by the above-mentioned general formula (1), a compound represented by the general formula (2), and a compound represented by the general formula (1). It is preferable to contain at least one of the compounds represented by (3).

Further, in the present invention, it is also preferable that the second luminescent material of the second particulate color conversion material contains at least a compound represented by the general formula (4) described below, from the viewpoint of obtaining luminescence with high color purity. .

As another embodiment of the color conversion member of the present invention, a color conversion member in which a plurality of types of supports containing particulate color conversion materials are combined is also preferable. For example, the color conversion member of the other embodiment includes a support containing a first particulate color conversion material that emits green light, a support containing a second particulate color conversion material that emits red light, Examples include those made by combining the following. That is, as a preferred embodiment of the present invention, the first support has a first particulate color conversion material consisting of a first luminescent material and a first matrix resin that exhibits luminescence observed in a region with a peak wavelength of 500 nm or more and less than 580 nm. and a second support having a second particulate color conversion material made of a second luminescent material and a second matrix resin that exhibits luminescence observed in a region with a peak wavelength of 580 nm or more and 750 nm or less. can be mentioned. Methods for combining multiple types of supports include a method of arranging them on the same plane, a method of stacking them, etc., depending on the shape of each support to be combined.

These first light-emitting materials and second light-emitting materials are not particularly limited, and include known light-emitting materials such as inorganic phosphors, fluorescent pigments, fluorescent dyes, and quantum dots. In particular, organic light-emitting materials are preferable as the first light-emitting material and the second light-emitting material because white light with high color reproducibility can be obtained.

By optimizing the combination of the organic luminescent material and matrix resin in each of the first particulate color conversion material and the second particulate color conversion material described above, the emission peak wavelength of the organic luminescent material is shifted to a desired wavelength, Color gamut can be expanded. That is, the first matrix resin of the first particulate color conversion material and the second matrix resin of the second particulate color conversion material may be the same resin or different resins. Note that the two matrix resins being different from each other means that the compositions of the resins are different.

Furthermore, there is a strong relationship between the SP value, which is the solubility parameter of the matrix resin, and the emission peak wavelength of the organic light-emitting material. In a matrix resin with a large SP value, the interaction between the matrix resin and the organic luminescent material stabilizes the excited state of the organic luminescent material. Therefore, compared to the matrix resin having a small SP value, the emission peak wavelength of this organic light-emitting material shifts to the longer wavelength side. Therefore, by dispersing the organic light-emitting material in a matrix resin having an optimal SP value, it is possible to optimize the emission peak wavelength of the organic light-emitting material.

For example, when the SP value of the first matrix resin is SP _A (cal/cm ³ ) ^0.5 and the SP value of the second matrix resin is SP _B (cal/cm ³ ) ^0.5 , SP _A ≦SP _B. is preferred. In this case, the difference in the emission peak wavelengths of green light and red light in the first particulate color conversion material and the second particulate color conversion material is greater than that in the case where the organic light emitting material is dispersed in the same matrix resin. As a result, the color gamut is expanded.

Among these, it is preferable that SP _B ≧9.5. The larger the value of SP _B is, the longer the emission peak wavelength of red light in the second particulate color conversion material becomes, and as a result, the second particulate color conversion material emits deep red light. be able to. From the viewpoint of increasing the effect, it is more preferable that SP _B ≧10.0.

Although the upper limit of SP _B is not particularly limited, a matrix resin in which SP _B ≦15.0 has good dispersibility of the organic light emitting material, and therefore can be suitably used. From the viewpoint of increasing the effect, it is more preferable that SP _B ≦14.0, still more preferably SP _B ≦13.0, particularly preferably SP _B ≦12.0.

Further, when SP _A ≦11.0, the emission peak wavelength of green light in the first particulate color conversion material is suppressed from becoming longer, and as a result, the first particulate color conversion material and the second particulate color The difference in the emission peak wavelengths of green light and red light in the conversion material increases. Therefore, it is preferable that SP _A ≦11.0. From the viewpoint of increasing the effect, it is more preferable that SP _A ≦10.5, and even more preferably that SP _A ≦10.0.

Although the lower limit of SP _A is not particularly limited, a matrix resin in which SP _A ≧7.0 has good dispersibility of the organic light-emitting material, and thus can be suitably used. From the viewpoint of increasing the effect, it is more preferable that SP _A ≧7.4, still more preferably SP _A ≧7.8, particularly preferably SP _A ≧8.0.

Here, the solubility parameter (SP value) is determined by the generally used Fedors estimation method described in Poly.Eng.Sci., vol. 14, No. 2, pp. 147-154 (1974), etc. This is a value calculated from the types and ratios of monomers constituting the resin. The SP value can also be calculated using a similar method for a mixture of multiple types of resins. For example, the SP value of polymethyl methacrylate can be calculated as 9.9 (cal/cm ³ ) ^0.5 , the SP value of polyethylene terephthalate (PET) can be calculated as 11.6 (cal/cm ^{3 ) 0.5, and the SP value of polymethyl methacrylate (PET) can be calculated as 11.6 (cal/cm 3} ) ^0.5 . The SP value of the epoxy resin can be calculated as 10.9 (cal/cm ³ ) ^0.5 .

Typical SP values of the resins are shown in Table 1. The above-described first matrix resin and second matrix resin can be used in any combination from among the resins shown in Table 1, for example.

As another embodiment of the color conversion member of the present invention, the support of the color conversion member preferably contains at least one type of luminescent material in addition to the particulate color conversion material of the present invention. Among them, from the viewpoint of color purity, it is more preferable that the support of the color conversion member contains at least one kind of organic light-emitting material, such as a compound containing a partial structure represented by the above-mentioned general formula (1), a general formula It is particularly preferable to contain at least one of the compound represented by (2) and the compound represented by general formula (3). Further, from the viewpoint of obtaining light emission with high color purity, it is also preferable that the support of the color conversion member contains at least a compound represented by general formula (4) as one of the above-mentioned light-emitting materials.

In general formula (4), X is CR ⁷ or N. R ¹ to R ⁹ may be the same or different, and include 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, Aryl ether group, arylthioether group, aryl group, heteroaryl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, boryl group , a phosphine oxide group, and a fused ring and an aliphatic ring formed between adjacent substituents. R ¹ to R ⁹ may each be independently substituted. The substituents for each of R ¹ to R ⁹ are selected from the same group as the substituent Ra in the above-mentioned general formula (2) or general formula (3).

From the viewpoint of photostability, X in general formula (4) is preferably CR ⁷ . In addition, from the viewpoint of providing a higher fluorescence quantum yield and being more difficult to thermally decompose, and from the viewpoint of photostability, X in general formula (4) is CR ⁷ and R ⁷ is substituted or unsubstituted. An aryl group is preferred. From the viewpoint of not impairing the emission wavelength, 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 substituted or unsubstituted phenyl group is more preferable. preferable.

In general formula (4), R ⁸ and R ⁹ are preferably fluorine, a fluorine-containing alkyl group, a fluorine-containing heteroaryl group, a fluorine-containing aryl group, or a cyano group. In particular, R ⁸ and R ⁹ are preferably fluorine or cyano groups, since they are stable to excitation light and a higher fluorescence quantum yield can be obtained.

As a first preferred example of the compound represented by the general formula (4), all of R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and are substituted or unsubstituted phenyl groups; , Further examples include the case where X is CR ⁷ and R ⁷ is a substituted or unsubstituted phenyl group. In this case, it is particularly preferred that at least one of R ¹ , R ³ , R ⁴ , R ⁶ and R ⁷ is a phenyl group substituted with a methoxy group.

As a second preferred example of the compound represented by general formula (4), all of R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and are substituted or unsubstituted alkyl groups; , Further examples include the case where X is CR ⁷ and R ⁷ is a substituted or unsubstituted phenyl group. In this case, R ² and R ⁵ may be the same or different, and are particularly preferably substituted or unsubstituted ester groups.

Further, as a third preferable example of the compound represented by the general formula (4), at least one of the four groups R ¹ and R ² , R ² and R ³ , R ⁴ and R ⁵ , and R ⁵ and R ⁶ The set may be a ring structure of any one of the following general formulas (5A) to (5D). Each ring structure represented by each of the general formulas (5A) to (5D) has a double bond. Therefore, by introducing any one of the ring structures into the above compound, the conjugation can be expanded and the wavelength of the emitted light can be increased. Furthermore, because the ring structure introduced into the above compound allows the double bond site to be fixed to the central skeleton through chemical bonds, excessive structural relaxation in the excited state can be suppressed, making it possible to obtain light emission with good color purity. can. In this third example, R ² and R ³ are ring structures represented by the general formula (5D), Ar in the general formula (5D) is a substituted or unsubstituted benzene ring, and the general formula (5D) R ¹⁰¹ and R ¹⁰² in the formula may be the same or different and are a substituted or unsubstituted alkyl group or a substituted or unsubstituted phenyl group, X is CR ⁷ , and R ⁷ is a substituted or A preferred example is an unsubstituted phenyl group. In this case, R ⁴ and R ⁶ may be the same or different, and are preferably substituted or unsubstituted phenyl groups. Further, it is also preferable that R ¹⁰¹ and R ¹⁰² in general formula (5D) form a ring. In general formulas (5A) to (5D), R ¹⁰¹ , R ¹⁰² and R ²⁰¹ to R ²⁰⁴ have the same meanings as R ¹ to R ⁷ in general formula (4) described above.

As another embodiment of the color conversion member of the present invention, the support of the color conversion member preferably has oxygen barrier properties. Oxygen barrier properties refer to characteristics of low oxygen permeability. In the present invention, the oxygen permeability of the support is preferably 1.0 cc/m ² ·day · atm or less, more preferably 0.5 cc/m 2 ·day · atm or less, and 0.5 cc/m ² ·day · atm or less. It is particularly preferable that it is 1 cc/m ² ·day · atm or less.

In addition, the oxygen permeability was measured using a flat test piece with a uniform film thickness, unless otherwise specified, under the conditions of a temperature of 20°C and a humidity of 0% RH. This value is measured using a measuring device (model name: "OXTRAN" (registered trademark) ("OXTRAN" 2/20)) based on the electrolytic sensor method described in JIS K7126-2 (2006). .

As mentioned above, in the absence of oxygen, the reaction between the highly reactive organic light-emitting material in the triplet excited state and surrounding molecules can be a factor in the deterioration of the organic light-emitting material. However, when the organic light-emitting material in the triplet excited state is a delayed fluorescent material, the delayed fluorescent material in the triplet excited state can be quickly converted to the delayed fluorescent material in the singlet excited state. Therefore, in the absence of oxygen, delayed fluorescent materials can exhibit significantly greater durability than conventional organic light emitting materials (organic light emitting materials that do not emit delayed fluorescence).

Further, as another embodiment of the color conversion member of the present invention, the color conversion member has an oxygen barrier layer (that is, an oxygen barrier layer) on at least a portion of the surface of the support, as shown in FIGS. 4 to 7, for example. It is also preferable to have When the permeation of oxygen into the support is blocked by an oxygen barrier layer, delayed fluorescent materials can exhibit significantly greater durability than conventional organic light-emitting materials, as described above. In the present invention, the oxygen permeability of the oxygen barrier layer is preferably 2.0 cc/m ² ·day · atm or less, more preferably 1.0 cc/m ² ·day · atm or less, It is more preferably 0.5 cc/m ² ·day · atm or less, and particularly preferably 0.1 cc/m ² ·day · atm or less.

Further, examples of the oxygen barrier layer include a glass layer, an inorganic oxide layer, an inorganic nitride layer, a resin layer, and the like. As the inorganic oxide constituting the oxygen barrier layer, from the viewpoint of cost, silicon oxide and aluminum oxide are preferable, and among them, aluminum oxide can be particularly preferably used. As the resin layer, which is an example of the oxygen barrier layer, from the viewpoint of high oxygen barrier properties, a layer made of polyol resin is more preferable, and among them, saponified vinyl acetate such as polyvinyl alcohol, ethylene-vinyl alcohol, etc. A layer made of a polymer and a mixture containing these resins is even more preferable because it has particularly excellent oxygen barrier properties.

As a further embodiment of the color conversion member of the present invention, the support containing the particulate color conversion material has oxygen barrier properties, and at least a part of the surface of the support is covered with the above-mentioned oxygen barrier layer. The color conversion member described above is also preferable because higher oxygen barrier properties can be obtained. For example, as for the structure of the color conversion member of the other embodiment, an oxygen barrier film or the like is provided on both sides of the layer (color conversion layer) of the color conversion member consisting of the particulate color conversion material of the present invention and an oxygen barrier support. An example is a structure in which barrier layers are laminated. In this case, the oxygen barrier properties of the support can prevent oxygen from entering from the edges of the entire surface of the support that are not covered with the barrier film, and the particulate color conversion material at the edges can be prevented from entering through the edges that are not covered with the barrier film. Deterioration can be suppressed.

The support that can be used in the color conversion member of the present invention can contain additives, if necessary, in addition to the particulate color conversion material and luminescent material described above. Examples of such additives include light-absorbing dyes, light-absorbing pigments, antioxidants, processing and heat stabilizers, light resistance stabilizers such as ultraviolet absorbers, dispersants and leveling agents, plasticizers, epoxy compounds, etc. curing agents such as amines, acid anhydrides, and imidazole, adhesion aids, inorganic particles such as titanium oxide particles, zirconia particles, and silica particles, and silane coupling agents.

<Method for manufacturing color conversion member>
The method for producing the color conversion member according to the embodiment of the present invention is not particularly limited as long as it is a method that can mold a support containing the particulate color conversion material of the present invention into a desired shape. For example, a composition is prepared by mixing the particulate color conversion material of the present invention, a resin serving as a support, a solvent, etc., and then the composition is applied onto a substrate and dried. Examples include a method of forming a support containing the particulate color conversion material of the invention into a sheet shape. Another example is a method in which the particulate color conversion material of the present invention and a resin serving as a support are kneaded while heating and molded using an extruder.

<Color conversion board>
A color conversion substrate according to an embodiment of the present invention (hereinafter sometimes abbreviated as "color conversion substrate of the present invention") includes at least the particulate color conversion material of the present invention or the color conversion member of the present invention. It is composed of For example, the color conversion substrate of the present invention includes a plurality of color conversion layers on a transparent substrate. In the present invention, the color conversion layer preferably includes a red conversion layer and a green conversion layer. The red conversion layer is formed of a phosphor material that absorbs at least blue light and emits red light. The green color conversion layer is formed of a phosphor material that absorbs at least blue light and emits green light. Moreover, partition walls may be formed in the color conversion substrate of the present invention, and the color conversion layer is preferably arranged between the partition walls (in a recess). The color conversion substrate of the present invention may be one in which excitation light is input from the transparent substrate side and emission is visually recognized from the side opposite to the transparent substrate, or excitation light is input from the color conversion layer side and the transparent substrate The light emission may be visually recognized from the side. The quantum yield of the color conversion layer is usually 0.5 or more, preferably 0.7 or more, more preferably 0 when the color conversion substrate is irradiated with blue light having a peak wavelength of 440 nm or more and 460 nm or less. .8 or more, particularly preferably 0.9 or more.

<Ink>
The particulate color conversion material or color conversion member of the present invention can also be used in ink. The ink according to the embodiment of the present invention (hereinafter sometimes abbreviated as "the ink of the present invention") is in a liquid, gel, or solid state containing at least the particulate color conversion material or color conversion member of the present invention. It is used for writing characters and coloring the surface. By using the particulate color conversion material or color conversion member of the present invention, the ink of the present invention can achieve both luminescence with high color purity and high durability. It can be preferably used as an ink.

<Light source unit>
A light source unit according to an embodiment of the present invention (hereinafter sometimes abbreviated as "a light source unit of the present invention") includes at least a light source and the above-mentioned particulate color conversion material or color conversion member. It is constructed. In the light source unit of the present invention, the method of arranging the light source and the particulate color conversion material or color conversion member is not particularly limited. Alternatively, a remote phosphor format may be used in which the light source and the particulate color conversion material or color conversion member are separated. Further, the light source unit of the present invention may further include a color filter for the purpose of increasing color purity.

<Light source>
As for the type of light source provided in the light source unit of the present invention, any light source may be used as long as it emits light in a wavelength range that can be absorbed by the particulate color conversion material of the present invention or the luminescent material used in the color conversion member. Can be done. For example, any excitation light source can be used in principle, such as hot cathode tubes, cold cathode tubes, fluorescent light sources such as inorganic electroluminescence (EL), organic EL light sources, LED light sources, incandescent light sources, or sunlight. It is possible. Among these, an LED light source is a suitable light source. For example, a light emitting diode having maximum emission in a wavelength range of 400 nm or more and 500 nm or less is a more suitable LED light source. For display and lighting applications, a light emitting diode (blue LED light source) having maximum emission in a wavelength range of 400 nm or more and 500 nm or less is a more suitable light source because it can enhance the color purity of blue light. Further, as the light source included in the light source unit of the present invention, a blue LED light source having maximum emission in a wavelength range of 430 nm or more and 480 nm or less is more preferable, and a blue LED light source having maximum emission in a wavelength range of 450 nm or more and 470 nm or less is more preferable. .

The above-mentioned light source may have one kind of luminescence peak or two or more kinds of luminescence peaks, but in order to improve color purity, it is preferable to have one kind of luminescence peak. It is also possible to use a plurality of light sources with different types of emission peaks in any combination.

The light source unit of the present invention is useful for various light sources such as space illumination and backlighting. Specifically, the light source unit of the present invention can be used for displays, lighting devices, interiors, signs, signboards, etc. Among them, it is particularly suitable for use in displays and lighting devices.

<Display, lighting equipment>
A display according to an embodiment of the present invention includes at least a light source unit including a light source and a particulate color conversion material or a color conversion member as described above. For example, the above-mentioned light source unit is used as a backlight unit in a display such as a liquid crystal display.

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

Hereinafter, the present invention will be explained with reference to examples, but the present invention is not limited to the following examples. First, measurement methods, evaluation methods, and luminescent materials in Examples and Comparative Examples will be explained.

<Measurement of color conversion characteristics>
In the measurement of color conversion characteristics, each color conversion member to be evaluated and a prism sheet were placed on a planar light emitting device equipped with a blue LED element with an emission peak wavelength of 450 nm. A current of 30 mA is applied to the planar light emitting device in this state to light up the blue LED element, and the emission spectrum, chromaticity, and brightness are measured using a spectroradiometer (CS-1000, manufactured by Konica Minolta). did.

<Calculation of color gamut>
In calculating the color gamut, the (u', v') color when the color purity is improved by the color filter is calculated from the emission spectrum obtained by measuring the color conversion characteristics mentioned above and the spectral data of the transmittance of the color filter. The color gamut in space was calculated. Also, the area of the calculated color gamut in the (u', v') color space is BT. Evaluation was made based on the following criteria based on the ratio when the color gamut area of the 2020 standard is taken as 100%. As an evaluation result of the area of the color gamut in this (u', v') color space, "A" indicates that the above ratio is 91% or more. "B" indicates that the above ratio is 86% or more and 90% or less. "C" indicates that the above ratio is 81% or more and 85% or less. In this evaluation result, the higher the above ratio, the wider the color gamut and the better the color reproducibility of the color conversion member.

<Durability evaluation>
In the durability evaluation, in each example and comparative example, a current of 30 mA was applied to a light emitting device equipped with the produced color conversion member and a blue LED element (manufactured by USHIO EPITEX, model number SMBB450H-1100, emission peak wavelength: 450 nm). The blue LED element was turned on, and the initial luminescence peak intensity was measured using a spectral radiance meter (CS-1000, manufactured by Konica Minolta). Note that the distance between the color conversion member and the blue LED element in this light emitting device was 3 cm. Thereafter, the durability of the color conversion member was evaluated by continuously irradiating it with light from a blue LED element in an environment of 60° C. and observing the time until the emission peak intensity decreased by 5%.

<Evaluation of edge deterioration>
In the evaluation of edge deterioration, light irradiation was performed for 300 hours under the same conditions as in the durability evaluation above, and compared to the center of the sample, the luminescence intensity was significantly reduced in the range of mm from the edge of the sample. was visually confirmed and evaluated using the following criteria. As an evaluation result of edge deterioration, "A" indicates that the distance from the edge is 0 mm or more and less than 1 mm. "B" indicates that the distance from the end is 1 mm or more and less than 5 mm. "C" indicates that the distance from the end is 5 mm or more. However, the sample of the color conversion member used for the measurement was a sheet-shaped sample cut into a size of 30 mm x 30 mm.

<Measurement of oxygen permeability>
In the measurement of oxygen permeability, a flat test piece with a uniform film thickness was used as the evaluation target. Unless otherwise specified, an oxygen permeability measuring device (model name: "OXTRAN" (registered trademark)) ("OXTRAN" 2/ 20)) was used to measure the oxygen permeability of the above flat test piece based on the electrolytic sensor method described in JIS K7126-2 (2006).

<Light-emitting material>
In the following examples and comparative examples, compounds G-1, G-2, G-3, G-4, G-5, R-1 are used as luminescent materials contained in particulate color conversion materials or color conversion members. was used. Compounds G-1, G-2, G-3, G-4, G-5, and R-1 are the compounds shown below. Among these, compounds G-1, G-3, G-4, and G-5 are compounds that emit delayed fluorescence (delayed fluorescence materials).

Example 1
In Example 1, first, polyester resin T1 (SP value = 10.7 (cal/cm ³ ) ^0.5 ) was used as a matrix resin, and compound G-1 was added as a luminescent material to 100 parts by weight of this matrix resin. 0.10 parts by weight and 600 parts by weight of tetrahydrofuran as a solvent were mixed. These mixtures were stirred and defoamed at 300 rpm for 30 minutes using a planetary stirring/defoaming device "Mazerstar" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.), thereby obtaining a color conversion composition. . This color conversion composition was dried by a spray drying method and further pulverized in a mortar to produce a particulate color conversion material. Regarding this particulate color conversion material, the particle size of 100 isolated particles was measured using ECLIPSE L200N (manufactured by Nikon Corporation), and the average value was calculated, and the average particle size was about 1 μm. The particle size was measured by selecting the part with the largest diameter.

Next, hydrogenated SEBS copolymer resin T2 (SP value = 8.5 (cal/cm ³ ) ^0.5 , oxygen permeability > 2000 cc/m ² ·day · atm) was used as a material for the support, and this resin 300 parts by weight of cyclohexane as a solvent was mixed with 100 parts by weight of cyclohexane. These mixtures were stirred and defoamed at 300 rpm for 30 minutes using a planetary stirring/defoaming device "Mazerstar" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.), thereby obtaining a resin liquid for the support. Ta.

Finally, the particulate color conversion material and the support resin liquid are mixed, and the mixture is stirred using a planetary stirring/defoaming device "Mazelstar" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.). A color conversion dispersion liquid was prepared by stirring and defoaming at 1000 rpm for 20 minutes. This color conversion dispersion liquid was applied onto a slide glass plate using a film applicator, heated at 120°C for 30 minutes, and dried to form a color conversion member (including particulate color conversion material) with an average thickness of 12 μm. Created.

When light from a blue LED element (blue light) was color-converted using the color conversion member produced as described above, when only the green light emission region was extracted, the peak wavelength was 523 nm, and the emission at the peak wavelength was found to be 523 nm. Green light emission with high color purity, with a spectral half width of 38 nm, was obtained. Further, when the light from the blue LED element was continuously irradiated according to the above method, the time until the brightness decreased by 5% (light durability) was about 60 hours. In Example 1, when compared with Comparative Example 3 described later, the light durability was improved by about 2.4 times. The color conversion member and evaluation results of Example 1 are shown in Table 2-1 below.

Examples 2-4
In Examples 2 to 4, color conversion members were produced and evaluated in the same manner as in Example 1, except that Compounds G-3 to G-5 were used as luminescent materials, respectively. However, the amount of the luminescent material mixed was adjusted so that the conversion rate when converting light from the blue LED element into green light was the same as that of Compound G-1 of Example 1. The color conversion member and evaluation results of Example 2 are shown in Table 2-1.

Comparative examples 1 and 2
In Comparative Examples 1 and 2, color conversion members were produced and evaluated in the same manner as in Example 1, except that Coumarine 6 (manufactured by Sigma-Aldrich) or Compound G-2 was used as the luminescent material. However, the amount of the luminescent material mixed was adjusted so that the conversion rate when converting light from the blue LED element into green light was the same as that of Compound G-1 of Example 1. The color conversion members and evaluation results in each of Comparative Examples 1 and 2 are shown in Table 2-1.

Comparative examples 3 to 8
In Comparative Examples 3 to 8, each color conversion composition prepared in Examples 1 to 4 and Comparative Examples 1 and 2 was applied onto a slide glass plate using a film applicator, heated at 120 ° C. for 30 minutes, It was dried to produce a film-like color conversion member (not containing particulate color conversion material). In each of Comparative Examples 3 to 8, durability was evaluated by measuring the peak wavelength and half-width when color-converting light from a blue LED element using the produced color conversion member. The color conversion members and evaluation results in each of Comparative Examples 3 to 8 are shown in Table 2-2 below. However, the oxygen permeability of polyester resin T1 was 600 cc/m ² ·day · atm.

Example 5
In Example 5, polyvinyl alcohol resin T3 (SP value = 12.6 (cal/cm ³ ) ^0.5 , oxygen permeability = 0.4 cc/m ² ·day · atm) was used as the material for the support. 400 parts by weight of a mixed solution of water/2-propanol as a solvent were mixed with 100 parts by weight of the mixture while heating and stirring, thereby obtaining a resin liquid for a support.

Next, the particulate color conversion material prepared in Example 1 and the support resin liquid of Example 5 were mixed, and the mixture was passed through a planetary stirring/defoaming device "Mazelstar" (registered trademark) KK- 400 (manufactured by Kurabo Industries, Ltd.) for 20 minutes with stirring and defoaming at 1000 rpm to prepare a color conversion dispersion. This color conversion dispersion liquid was applied onto a slide glass plate using a film applicator, heated at 100°C for 60 minutes, and dried to form a color conversion member (including particulate color conversion material) with an average film thickness of 9 μm. Created.

When light from a blue LED element was color-converted using the color conversion member produced as described above, when only the green light emission region was extracted, the peak wavelength was 523 nm, and the half-value width of the emission spectrum at the peak wavelength. Green emission with high color purity of 38 nm was obtained. Further, when the light from the blue LED element was continuously irradiated according to the above method, it took about 600 hours until the brightness decreased by 5%. In Example 5, compared to Example 1, the light durability was improved by about 10 times. The color conversion member and evaluation results of Example 5 are as shown in Table 3 below.

Examples 6-8
In Examples 6 to 8, color conversion members were produced and evaluated in the same manner as in Example 5, except that the particulate color conversion materials produced in Examples 2 to 4 were used as particulate color conversion materials. Ta. The color conversion members and evaluation results in each of Examples 6 to 8 are shown in Table 3.

Example 9
In Example 9, polyvinyl alcohol resin T5 (SP value = 12.2 (cal/cm ³ ) ^0.5 , oxygen permeability = 0.8 cc/m ² ·day · atm) was used as the material for the support. A color conversion member was produced and evaluated in the same manner as in Example 5. The color conversion member and evaluation results of Example 9 are shown in Table 3.

Example 10
In Example 10, ethylene vinyl alcohol copolymer resin T6 (SP value = 10.9 (cal/cm ³ ) ^0.5 , oxygen permeability = 4.0 cc/m ² ·day · atm) was used as the material for the support. A color conversion member was produced and evaluated in the same manner as in Example 5 except for the following. The color conversion member and evaluation results of Example 10 are shown in Table 3.

Comparative examples 9 and 10
In Comparative Examples 9 and 10, color conversion members were produced and evaluated in the same manner as in Example 5, except that each of the particulate color conversion materials produced in Comparative Examples 1 and 2 was used as the particulate color conversion material. went. The color conversion members and evaluation results in each of Comparative Examples 9 and 10 are shown in Table 3.

Example 11
In Example 11, first, polyester resin T1 (SP value = 10.7 (cal/cm ³ ) ^0.5 ) was used as a matrix resin, and compound G-1 was added as a luminescent material to 100 parts by weight of this matrix resin. 0.10 parts by weight and 600 parts by weight of tetrahydrofuran as a solvent were mixed. These mixtures were stirred and defoamed at 300 rpm for 30 minutes using a planetary stirring/defoaming device "Mazerstar" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.), thereby obtaining a color conversion composition. . This color conversion composition was dried by a spray drying method and further pulverized in a mortar to produce a first particulate color conversion material having an average particle size of about 1 μm.

Similarly to the above, polyester resin T1 (SP value = 10.7 (cal/cm ³ ) ^0.5 ) was used as the matrix resin, and 0.0% of compound R-1 was added as the luminescent material to 100 parts by weight of this matrix resin. 10 parts by weight and 600 parts by weight of tetrahydrofuran as a solvent were mixed. These mixtures were stirred and defoamed at 300 rpm for 30 minutes using a planetary stirring/defoaming device "Mazerstar" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.), thereby obtaining a color conversion composition. . This color conversion composition was dried by a spray drying method and further pulverized in a mortar to produce a second particulate color conversion material having an average particle size of about 1 μm.

Next, hydrogenated SEBS copolymer resin T2 (SP value = 8.5 (cal/cm ³ ) ^0.5 ) was used as a material for the support, and 300 parts by weight of cyclohexane was added as a solvent to 100 parts by weight of this resin. Parts by weight were mixed. These mixtures were stirred and defoamed at 300 rpm for 30 minutes using a planetary stirring/defoaming device "Mazerstar" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.), thereby obtaining a resin liquid for the support. Ta.

Finally, the first particulate color conversion material, the second particulate color conversion material, and the support resin liquid were mixed and stirred to prepare a color conversion dispersion. This color conversion dispersion liquid was applied onto a slide glass plate using a film applicator, heated at 120° C. for 30 minutes, and dried to produce a color conversion member (containing particulate color conversion material).

When the color conversion member produced as described above was used to convert the light (blue light) from the blue LED element, part of the blue light was converted into green light and red light, and white light was obtained. Ta. When only the green light emission region was extracted, green light emission with high color purity was obtained, with a peak wavelength of 523 nm and a half width of the emission spectrum at the peak wavelength of 36 nm. Further, when only the red light emission region was extracted, red light emission with high color purity was obtained, with a peak wavelength of 641 nm and a half width of the emission spectrum at the peak wavelength of 50 nm. The area of the color gamut in the (u', v') color space is BT. It was 91% of the color gamut area of the 2020 standard. The color conversion member and evaluation results of Example 11 are as shown in Table 4 below. In Table 4, "color gamut area" is the area of the color gamut in the (u', v') color space. Further, "A" to "C" in the "color gamut area" column indicate the evaluation results of the area of this color gamut.

Example 12
In Example 12, the color was changed in the same manner as in Example 11 except that acrylic resin T4 (SP value = 9.8 (cal/cm ³ ) ^0.5 ) was used as the matrix resin of the second particulate color conversion material. A conversion member was manufactured and evaluated. The color conversion member and evaluation results of Example 12 are shown in Table 4.

Example 13
In Example 13, the color was changed in the same manner as in Example 11 except that acrylic resin T4 (SP value = 9.8 (cal/cm ³ ) ^0.5 ) was used as the matrix resin of the first particulate color conversion material. A conversion member was manufactured and evaluated. The color conversion member and evaluation results of Example 13 are shown in Table 4.

Example 14
In Example 14, first, polyester resin T1 (SP value = 10.7 (cal/cm ³ ) ^0.5 ) was used as a matrix resin, and compound G-1 was added as a luminescent material to 100 parts by weight of this matrix resin. 0.10 parts by weight of Compound R-1, 0.10 parts by weight of Compound R-1, and 600 parts by weight of tetrahydrofuran as a solvent were mixed. These mixtures were stirred and defoamed at 300 rpm for 30 minutes using a planetary stirring/defoaming device "Mazerstar" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.), thereby obtaining a color conversion composition. . This color conversion composition was dried by a spray drying method and further pulverized in a mortar to produce a first particulate color conversion material having an average particle size of about 1 μm.

Next, hydrogenated SEBS copolymer resin T2 (SP value = 8.5 (cal/cm ³ ) ^0.5 ) was used as the material for the support, and a resin liquid for the support was obtained in the same manner as in Example 3. .

Finally, the first particulate color conversion material and the support resin liquid were mixed and stirred to prepare a color conversion dispersion. This color conversion dispersion liquid was applied onto a slide glass plate using a film applicator, heated at 120° C. for 30 minutes, and dried to produce a color conversion member (containing particulate color conversion material). Evaluation was performed in the same manner as in Example 11 using the produced color conversion member. The color conversion member and evaluation results of Example 14 are shown in Table 4.

Comparative example 11
In Comparative Example 11, Coumarine 6 (manufactured by Sigma-Aldrich) was used as the luminescent material of the first particulate color conversion material, and the conversion rate when converting light from a blue LED element into green light was that of Compound G- of Example 11. Lumogen F Red305 (manufactured by BASF) was used as the luminescent material of the second particulate color conversion material, and the amount of substance was adjusted to be the same as that of Compound R-1 of Example 11. A color conversion member was produced and evaluated in the same manner as in Example 11, except that the mixture was adjusted to . The color conversion member and evaluation results of Comparative Example 11 are shown in Table 4.

Example 15
In Example 15, first, polyester resin T1 (SP value = 10.7 (cal/cm ³ ) ^0.5 ) was used as a matrix resin, and compound G-1 was added as a luminescent material to 100 parts by weight of this matrix resin. 0.10 parts by weight and 600 parts by weight of tetrahydrofuran as a solvent were mixed. These mixtures were stirred and defoamed at 300 rpm for 30 minutes using a planetary stirring/defoaming device "Mazerstar" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.), thereby obtaining a color conversion composition. . This color conversion composition was dried by a spray drying method and further pulverized in a mortar to produce a particulate color conversion material having an average particle size of about 1 μm.

Next, acrylic resin T4 (SP value = 9.8 (cal/cm ³ ) ^0.5 , oxygen permeability = 600 cc/m ² ·day · atm) was used as a material for the support, and 100 parts by weight of this resin was added to On the other hand, 0.03 parts by weight of Compound R-1 as a luminescent material, 200 parts by weight of ethyl acetate and 200 parts by weight of 1-methoxy-2-propanol as solvents were mixed. These mixtures were stirred and defoamed at 300 rpm for 30 minutes using a planetary stirring/defoaming device "Mazerstar" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.), thereby obtaining a resin liquid for the support. Ta.

Finally, the particulate color conversion material and the support resin liquid were mixed and stirred to prepare a color conversion dispersion. This color conversion dispersion liquid was applied onto a slide glass plate using a film applicator, heated at 120° C. for 30 minutes, and dried to produce a color conversion member (containing particulate color conversion material).

When light from a blue LED element was color-converted using the color conversion member produced as described above, when only the green light emission region was extracted, the peak wavelength was 523 nm, and the half-value width of the emission spectrum at the peak wavelength. Green emission with high color purity of 33 nm was obtained. Further, when only the red light emission region was extracted, red light emission with high color purity was obtained, with a peak wavelength of 630 nm and a half width of the emission spectrum at the peak wavelength of 49 nm. The area of the color gamut in the (u', v') color space is BT. It was 86% of the color gamut area of the 2020 standard. The color conversion member and evaluation results of Example 15 are as shown in Table 5 below. In Table 5, "color gamut area" is the area of the color gamut in the (u', v') color space. Further, "A" to "C" in the "color gamut area" column indicate the evaluation results of the area of this color gamut.

Example 16
In Example 16, the color conversion dispersion prepared in Example 5 was applied onto "Therapel" (registered trademark) BLK (release film manufactured by Toray Film Processing Co., Ltd.) using a film applicator, and heated at 100°C. The mixture was heated and dried for 60 minutes to produce a color conversion member (including particulate color conversion material) having an average thickness of 9 μm.

Next, as the oxygen barrier laminated film 1 constituting the oxygen barrier layer, an alumina-deposited polyethylene terephthalate film with a coating layer "Barrierox" (registered trademark) 1011SBR2 (manufactured by Toray Industries, Ltd., thickness 12 μm, oxygen permeability of about 0 A thermosetting adhesive layer was formed on this coating ^layer by a coating method, and the oxygen barrier laminate film 1 was laminated on one side of the color conversion member. Thereafter, "Therapel" (registered trademark) BLK was peeled off from this color conversion member, and the oxygen barrier laminate film 1 on which a thermosetting adhesive layer was formed in the same manner as above was laminated on the peeled surface. In this way, a color conversion member (including particulate color conversion material) having oxygen barrier layers on both sides was produced.

When the color conversion member produced as described above was continuously irradiated with light from a blue LED element, the time until the brightness decreased by 5% (light durability) was about 1000 hours. The durability evaluation of Example 16 showed that the light durability was improved by about 8.3 times when compared with Comparative Example 12, which will be described later. Furthermore, no end deterioration was observed at the ends of the sample. The color conversion member and evaluation results of Example 16 are shown in Table 6-1 below.

Example 17
In Example 17, a thermosetting adhesive layer was formed on a polyethylene terephthalate film "Lumirror" (registered trademark) U48 (manufactured by Toray Industries, Inc., thickness 50 μm) by a coating method, and on top of that, as an oxygen barrier layer. , an ethylene-vinyl alcohol copolymer film (ethylene content 32 mol%, thickness 12 μm) was laminated. In this way, an oxygen barrier laminate film 2 constituting an oxygen barrier layer was produced. The oxygen permeability of this oxygen barrier laminate film 2 was approximately 0.7 cc/m ² ·day · atm. A color conversion member (including particulate color conversion material) was prepared in the same manner as in Example 16 except that a thermosetting adhesive layer was formed on the ethylene-vinyl alcohol copolymer film of this oxygen barrier laminated film 2. were produced and evaluated. The color conversion member and evaluation results of Example 17 are shown in Table 6-1.

Example 18
In Example 18, the color conversion dispersion prepared in Example 1 was heated at 120° C. for 30 minutes and dried to produce a color conversion member (including particulate color conversion material) with an average thickness of 12 μm. Except for this, a color conversion member (including particulate color conversion material) was produced and evaluated in the same manner as in Example 16. The color conversion member and evaluation results of Example 18 are shown in Table 6-1.

Example 19
In Example 19, the color conversion dispersion prepared in Example 1 was heated at 120° C. for 30 minutes and dried to produce a color conversion member (including particulate color conversion material) with an average film thickness of 12 μm. Except for this, a color conversion member (including particulate color conversion material) was produced and evaluated in the same manner as in Example 17. The color conversion member and evaluation results of Example 19 are shown in Table 6-1.

Example 20
In Example 20, as the oxygen barrier laminated film 3 constituting the oxygen barrier layer, an alumina vapor-deposited polyethylene terephthalate film "Barrierox" (registered trademark) 1011HG (manufactured by Toray Industries, Inc., thickness 12 μm, oxygen permeability: A color conversion member (particulate color conversion material) was prepared in the same manner as in Example ¹⁸ except that a thermosetting adhesive layer was formed on the alumina layer of this film. (including materials) were prepared and evaluated. The color conversion member and evaluation results of Example 20 are shown in Table 6-1.

Comparative example 12
In Comparative Example 12, the color conversion composition prepared in Example 1 was applied onto "Therapel" (registered trademark) BLK (release film manufactured by Toray Film Processing Co., Ltd.) using a film applicator, and heated at 120°C. The mixture was heated for 30 minutes and dried to produce a film-like color conversion member (not containing particulate color conversion material). Oxygen barrier laminated film 3 was laminated on both sides of this film-like color conversion member by the same method as in Example 20, thereby forming the color conversion member of Comparative Example 12 (particles) having an oxygen barrier layer on both sides. (containing no color conversion material) was prepared. Thereafter, the color conversion member of Comparative Example 12 was evaluated. The color conversion member and evaluation results of Comparative Example 12 are shown in Table 6-2.

As described above, the particulate color conversion material, the color conversion member, and the light source unit, display, lighting device, and color conversion board including the same according to the present invention are suitable for achieving both improved color reproducibility and improved durability. ing.

1A, 1B, 1C, 1D, 1E, 1F, 1G Color conversion member 2a, 2b Particulate color conversion material 3a, 3b Support 11 Oxygen barrier layer

Claims (19)

1. A particulate color conversion material comprising a matrix resin and at least one luminescent material, the particulate color conversion material comprising:
   The at least one type of luminescent material includes an organic luminescent material that emits delayed fluorescence with a half width of 50 nm or less.
   A particulate color conversion material characterized by:
2. The organic light-emitting material is a compound containing a partial structure represented by general formula (1),
   The particulate color conversion material according to claim 1, characterized in that:
   

   

   (In general formula (1), B is a boron atom, N is a nitrogen atom, and C is a carbon atom. n is an integer from 0 to 2. When n is 0, the general formula The partial structure represented by (1) shows a direct bond structure between B and N.)
3. The organic light-emitting material is a compound containing two or more partial structures represented by the general formula (1),
   The particulate color conversion material according to claim 2, characterized in that:
4. The organic luminescent material contains a compound represented by general formula (2) or general formula (3),
   The particulate color conversion material according to claim 1, characterized in that:
   

   

   (In general formula (2) or general formula (3), ring Za, ring Zb and ring Zc each independently represent a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms, or a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms, or a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms. It is a heteroaryl ring having 6 to 30 ring carbon atoms. Z ¹ and Z ² are each independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra), or a sulfur atom. Z ¹ is NRa In this case, the substituent Ra may be combined with ring Za or ring Zb to form a ring. When Z ² is NRa, the substituent Ra may be combined with ring Za or ring Zc to form a ring. E is a boron atom, a phosphorus atom, SiRa (a silicon atom having a substituent Ra), or P=O. E ¹ and E ² each independently represent a BRa (a boron atom having a substituent Ra). ), PRa (phosphorous atom having a substituent Ra), SiRa ₂ (silicon atom having two substituents Ra), P(=O)Ra ₂ (phosphine oxide having two substituents Ra) or P(=S ) Ra ₂ (phosphine sulfide having two substituents Ra), C=O (carbonyl group), S(=O) or S(=O) ₂ . ^{E 1} is BRa, PRa, SiRa ₂ , P( When =O)Ra ₂ or P(=S)Ra ₂ , the substituent Ra may be combined with ring Za or ring Zb to form a ring. E ² is BRa, PRa, SiRa ₂ , P When (=O)Ra ₂ or P(=S)Ra ₂ , the substituent Ra may be bonded with ring Za or ring Zc to form a ring. Each substituent Ra independently represents hydrogen , substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, substituted or unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkenyl group, substituted or unsubstituted alkynyl group, hydroxyl group, thiol group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted aryl ether group, substituted or unsubstituted arylthioether group, halogen, cyano group, aldehyde group, substituted or unsubstituted carbonyl group, substituted or unsubstituted carboxyl group, substituted or unsubstituted oxycarbonyl group, substituted or unsubstituted ester group, substitution or unsubstituted carbamoyl group, substituted or unsubstituted amide group, sulfonyl group, substituted or unsubstituted sulfonic acid ester group, substituted or unsubstituted sulfonamide group, substituted or unsubstituted amino group, substituted or unsubstituted Formed between imino group, nitro group, substituted or unsubstituted silyl group, substituted or unsubstituted siloxanyl group, substituted or unsubstituted boryl group, substituted or unsubstituted phosphine oxide group, and adjacent substituents A substituent selected from fused rings and aliphatic rings. Further, the substituent Ra may be further substituted with the selected substituent, and these substituents may be further substituted with the selected substituent. )
5. E in the general formula (2) is a boron atom, and E ¹ and E ² in the general formula (3) are BRa,
   The particulate color conversion material according to claim 4, characterized in that:
6. comprising a support containing the particulate color conversion material according to any one of claims 1 to 5,
   A color conversion member characterized by:
7. The color conversion member is
   a first particulate color conversion material consisting of a first luminescent material and a first matrix resin that exhibits luminescence observed in a region with a peak wavelength of 500 nm or more and less than 580 nm;
   a second particulate color conversion material consisting of a second luminescent material and a second matrix resin that exhibits luminescence observed in a region with a peak wavelength of 580 nm or more and 750 nm or less;
   including,
   The color conversion member according to claim 6, characterized in that:
8. The first luminescent material includes at least an organic luminescent material that emits delayed fluorescence with a half width of 50 nm or less.
   The color conversion member according to claim 7, characterized in that:
9. The second luminescent material contains at least a compound represented by general formula (4).
   The color conversion member according to claim 7, characterized in that:
   

   

   (In ^the general formula ( ⁴ ) ^, group, cycloalkenyl group, alkynyl group, hydroxyl group, thiol group, alkoxy group, alkylthio group, aryl ether group, arylthioether group, aryl group, heteroaryl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, oxy R ¹ selected from carbonyl groups, carbamoyl groups, amino groups, nitro groups, silyl groups, siloxanyl groups, boryl groups, phosphine oxide groups, and fused rings and aliphatic rings formed between adjacent substituents. ~R ⁹ may each be independently substituted.The substituents for each of R ¹ ~R ⁹ include hydrogen, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or Unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkenyl group, substituted or unsubstituted alkynyl group, hydroxyl group , thiol group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted aryl ether group, substituted or unsubstituted arylthioether group, halogen, cyano group, aldehyde group, substituted or unsubstituted carbonyl group, substituted or unsubstituted carboxyl group, substituted or unsubstituted oxycarbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted amide group, sulfonyl group, substituted or Unsubstituted sulfonic acid ester group, substituted or unsubstituted sulfonamide group, substituted or unsubstituted amino group, substituted or unsubstituted imino group, nitro group, substituted or unsubstituted silyl group, substituted or unsubstituted siloxanyl group, substituted or unsubstituted boryl group, substituted or unsubstituted phosphine oxide group, and fused rings and aliphatic rings formed between adjacent substituents.)
10. The support further contains at least one luminescent material.
    The color conversion member according to claim 6, characterized in that:
11. The at least one luminescent material is at least one of a compound containing a partial structure represented by general formula (1), a compound represented by general formula (2), and a compound represented by general formula (3). containing,
    The color conversion member according to claim 10.
    

    

    (In general formula (1), B is a boron atom, N is a nitrogen atom, and C is a carbon atom. n is an integer from 0 to 2. When n is 0, the general formula The partial structure represented by (1) shows a direct bond structure between B and N.)
    

    

    (In general formula (2) or general formula (3), ring Za, ring Zb and ring Zc each independently represent a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms, or a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms, or a substituted or unsubstituted aryl ring having 6 to 30 ring carbon atoms. It is a heteroaryl ring having 6 to 30 ring carbon atoms. Z ¹ and Z ² are each independently an oxygen atom, NRa (a nitrogen atom having a substituent Ra), or a sulfur atom. Z ¹ is NRa In this case, the substituent Ra may be combined with ring Za or ring Zb to form a ring. When Z ² is NRa, the substituent Ra may be combined with ring Za or ring Zc to form a ring. E is a boron atom, a phosphorus atom, SiRa (a silicon atom having a substituent Ra), or P=O. E ¹ and E ² each independently represent a BRa (a boron atom having a substituent Ra). ), PRa (phosphorous atom having a substituent Ra), SiRa ₂ (silicon atom having two substituents Ra), P(=O)Ra ₂ (phosphine oxide having two substituents Ra) or P(=S ) Ra ₂ (phosphine sulfide having two substituents Ra), C=O (carbonyl group), S(=O) or S(=O) ₂ . ^{E 1} is BRa, PRa, SiRa ₂ , P( When =O)Ra ₂ or P(=S)Ra ₂ , the substituent Ra may be combined with ring Za or ring Zb to form a ring. E ² is BRa, PRa, SiRa ₂ , P When (=O)Ra ₂ or P(=S)Ra ₂ , the substituent Ra may be bonded with ring Za or ring Zc to form a ring. Each substituent Ra independently represents hydrogen , substituted or unsubstituted aryl group, substituted or unsubstituted heteroaryl group, substituted or unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkenyl group, substituted or unsubstituted alkynyl group, hydroxyl group, thiol group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted aryl ether group, substituted or unsubstituted arylthioether group, halogen, cyano group, aldehyde group, substituted or unsubstituted carbonyl group, substituted or unsubstituted carboxyl group, substituted or unsubstituted oxycarbonyl group, substituted or unsubstituted ester group, substitution or unsubstituted carbamoyl group, substituted or unsubstituted amide group, sulfonyl group, substituted or unsubstituted sulfonic acid ester group, substituted or unsubstituted sulfonamide group, substituted or unsubstituted amino group, substituted or unsubstituted Formed between imino group, nitro group, substituted or unsubstituted silyl group, substituted or unsubstituted siloxanyl group, substituted or unsubstituted boryl group, substituted or unsubstituted phosphine oxide group, and adjacent substituents A substituent selected from fused rings and aliphatic rings. Further, the substituent Ra may be further substituted with the selected substituent, and these substituents may be further substituted with the selected substituent. )
12. The at least one luminescent material contains at least a compound represented by general formula (4),
    The color conversion member according to claim 10.
    

    

    (In ^the general formula ( ⁴ ) ^, group, cycloalkenyl group, alkynyl group, hydroxyl group, thiol group, alkoxy group, alkylthio group, aryl ether group, arylthioether group, aryl group, heteroaryl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, oxy R ¹ selected from carbonyl groups, carbamoyl groups, amino groups, nitro groups, silyl groups, siloxanyl groups, boryl groups, phosphine oxide groups, and fused rings and aliphatic rings formed between adjacent substituents. ~R ⁹ may each be independently substituted.The substituents for each of R ¹ ~R ⁹ include hydrogen, a substituted or unsubstituted aryl group, a substituted or unsubstituted heteroaryl group, a substituted or Unsubstituted alkyl group, substituted or unsubstituted cycloalkyl group, substituted or unsubstituted heterocyclic group, substituted or unsubstituted alkenyl group, substituted or unsubstituted cycloalkenyl group, substituted or unsubstituted alkynyl group, hydroxyl group , thiol group, substituted or unsubstituted alkoxy group, substituted or unsubstituted alkylthio group, substituted or unsubstituted aryl ether group, substituted or unsubstituted arylthioether group, halogen, cyano group, aldehyde group, substituted or unsubstituted carbonyl group, substituted or unsubstituted carboxyl group, substituted or unsubstituted oxycarbonyl group, substituted or unsubstituted ester group, substituted or unsubstituted carbamoyl group, substituted or unsubstituted amide group, sulfonyl group, substituted or Unsubstituted sulfonic acid ester group, substituted or unsubstituted sulfonamide group, substituted or unsubstituted amino group, substituted or unsubstituted imino group, nitro group, substituted or unsubstituted silyl group, substituted or unsubstituted siloxanyl group, substituted or unsubstituted boryl group, substituted or unsubstituted phosphine oxide group, and fused rings and aliphatic rings formed between adjacent substituents.)
13. The oxygen permeability of the support is 1.0 cc/m ² ·day · atm or less,
    The color conversion member according to claim 6, characterized in that:
14. having an oxygen barrier layer on at least a part of the surface of the support;
    The color conversion member according to claim 6, characterized in that:
15. a light source and
    Particulate color conversion material according to any one of claims 1 to 5,
    A light source unit comprising:
16. The light source is a light emitting diode having maximum emission in a wavelength range of 400 nm or more and 500 nm or less,
    The light source unit according to claim 15.
17. comprising a light source unit according to claim 15;
    A display characterized by:
18. comprising a light source unit according to claim 15;
    A lighting device characterized by:
19. Containing the particulate color conversion material according to any one of claims 1 to 5,
    A color conversion board characterized by:

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