JP7306265B2 - Color conversion composition, color conversion sheet, light source unit, display and lighting device - Google Patents

Description

The present invention relates to a color conversion composition, a color conversion sheet, a light source unit, a display and an illumination device.

2. Description of the Related Art The application of a multi-color technique using a color conversion system to liquid crystal displays, organic EL displays, lighting devices, and the like is being actively studied. Color conversion is conversion of light emitted from a light-emitting body into light with a longer wavelength, for example, conversion of blue light emission into green or red light emission.

The composition having this color conversion function (hereinafter referred to as "color conversion composition") is formed into a sheet and combined with, for example, a blue light source to extract the three primary colors of blue, green, and red from the blue light source, i.e., white light. can be extracted. A white light source unit that combines such a blue light source and a sheet having a color conversion function (hereinafter referred to as a "color conversion sheet") is called a backlight unit, and this backlight unit, a liquid crystal driving part, and a color filter Combining them makes it possible to create a full-color display. Moreover, if there is no liquid crystal drive part, it can be used as a white light source as it is, and can be applied as a white light source such as LED illumination.

A problem with liquid crystal displays that use the color conversion method is the improvement of color reproducibility. In order to improve the color reproducibility, it is effective to narrow the half-value width of each emission spectrum of blue, green, and red of the backlight unit and to increase the color purity of each of blue, green, and red.

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

Also, a technique has been proposed in which an organic luminescent material is used as a component of a color conversion composition instead of quantum dots. Examples of techniques using an organic luminescent material as a component of a color conversion composition include those using coumarin derivatives (see, for example, Patent Document 2), those using rhodamine derivatives (see, for example, Patent Document 3), and pyrromethene derivatives. (see, for example, Patent Document 4). In addition, a technique of adding a light stabilizer has been disclosed in order to prevent deterioration of the organic light-emitting material and improve its durability (see, for example, Patent Document 5).

Japanese Unexamined Patent Application Publication No. 2012-22028 JP 2007-273440 A Japanese Patent Application Laid-Open No. 2001-164245 JP 2011-241160 A WO2011/149028

In recent years, along with higher definition such as 4K and 8K, high dynamic range (HDR), and higher contrast due to local dimming, the illuminance required for backlight units of liquid crystal displays is increasing. Therefore, in addition to high durability of the color conversion composition, it is necessary that the color conversion composition has high luminous efficiency.

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

In addition, when using an organic light-emitting material, existing techniques such as selection and improvement of the organic light-emitting material and addition of a specific light stabilizer are effective in improving durability, but the luminous efficiency of the color conversion composition is low. was still insufficient. That is, in the color conversion compositions using the organic light-emitting materials described in Patent Documents 2 to 5, techniques for achieving both high durability and high luminous efficiency are still insufficient.

The problem to be solved by the present invention is to achieve both high durability and high luminous efficiency in a color conversion composition used in displays such as liquid crystal displays and lighting devices such as LED lighting. An object of the present invention is to achieve both high durability and high luminous efficiency in a color conversion composition using an organic luminescent material that exhibits pure luminescence. That is, an object of the present invention is to provide a color conversion composition and a color conversion sheet that achieve both improved durability and improved luminous efficiency. With the goal.

As a result of intensive studies, the present inventors found that the energy of the highest occupied molecular orbital (hereinafter appropriately referred to as "HOMO") and the lowest unoccupied molecular orbital (hereinafter appropriately referred to as "LUMO") of the light-emitting material in the color conversion composition It has been found that both high luminance and high durability can be achieved when a predetermined relationship is satisfied between the levels and the HOMO and LUMO energy levels of the repeating units of the binder resin.

That is, in order to solve the above-described problems and achieve the object, the color conversion composition according to the present invention is a color conversion composition that converts incident light into light having a longer wavelength than the incident light, A component (A) that is m types of organic light-emitting materials (m is a natural number) and a component (B) that is a binder resin having n types of repeating units (n is a natural number), wherein the m types of organic light-emitting materials For the material, the energy level of the highest occupied molecular orbital is E _Ah (H) [eV], the energy level of the lowest unoccupied molecular orbital is E _Ah (L) [eV], and for the n types of repeating units, the highest When the energy level of the occupied orbital is E _Bi (H) [eV] and the energy level of the lowest unoccupied molecular orbital is E _Bi (L) [eV], for the component (A) and the component (B), E _Ah (H), E _Ah (L), E _Bi (H), and E _Bi (L) are characterized by satisfying (Formula-1).
E _Bi (H) ≤ E _Ah (H) ≤ E _Ah (L) ≤ E _Bi (L) (Formula-1)

Further, in the color conversion composition according to the present invention, in the above invention, E _Ah (H) and E _Bi (H) satisfy (Formula-2) with respect to the (A) component and the (B) component, It is characterized by
E _Bi (H) ≤ E _Ah (H) - 0.05 (Formula-2)

Further, in the color conversion composition according to the present invention, in the above invention, E _Ah (L) and E _Bi (L) of the (A) component and the (B) component satisfy (Formula-3), It is characterized by
E _Ah (L) + 0.05 ≤ E _Bi (L) (Formula-3)

Further, in the color conversion composition according to the present invention, in the above invention, E _Ah (H) of the component (A) satisfies either (Formula-4) or (Formula-5). Characterized by
E _Ah (H) ≤ -5.00 (Formula-4)
E _Ah (H)≧−4.50 (Formula-5)

Further, the color conversion composition according to the present invention is characterized in that, in the above invention, at least one of the m types of organic light-emitting materials satisfies (Formula-6).
E _Ah (H) ≤ -5.00 (Formula-6)

Further, in the color conversion composition according to the present invention, in the above invention, the component (B) is an acrylic resin, a copolymer resin containing an acrylic acid ester or methacrylic acid ester moiety, or a polyester resin. characterized by

Further, the color conversion composition according to the present invention is characterized in that, in the above invention, the component (B) is a thermoplastic resin.

In addition, the color conversion composition according to the present invention includes a component (C) which is q kinds of organic compounds (q is a natural number) in addition to the component (A) and the component (B) in the above invention, For the q kinds of organic compounds, when the energy level of the highest occupied molecular orbital is E _Cj (H) [eV] and the energy level of the lowest unoccupied molecular orbital is E _Cj (L) [eV], the above (A ) component and the component (C), E _Ah (H), E _Ah (L), E _Cj (H), and E _Cj (L) satisfy (Equation-7).
E _Cj (H) ≤ E _Ah (H) ≤ E _Ah (L) ≤ E _Cj (L) (Formula-7)

Further, the color conversion composition according to the present invention is characterized in that, in the above invention, the component (A) contains at least a compound represented by general formula (1).

（Ｘは、Ｃ－Ｒ^７またはＮである。Ｒ^１～Ｒ^９は、それぞれ同じでも異なっていてもよく、水素、アルキル基、シクロアルキル基、複素環基、アルケニル基、シクロアルケニル基、アルキニル基、水酸基、チオール基、アルコキシ基、アルキルチオ基、アリールエーテル基、アリールチオエーテル基、アリール基、ヘテロアリール基、ハロゲン、シアノ基、アルデヒド基、カルボニル基、カルボキシル基、エステル基、カルバモイル基、アミノ基、ニトロ基、シリル基、シロキサニル基、ボリル基、スルホ基、ホスフィンオキシド基、および隣接置換基との間に形成される縮合環および脂肪族環の中から選ばれる。）

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

Further, in the color conversion composition according to the present invention, in the above invention, X in the general formula (1) is C—R ⁷ and R ⁷ is a group represented by the general formula (2) It is characterized by

（ｒは、水素、アルキル基、シクロアルキル基、複素環基、アルケニル基、シクロアルケニル基、アルキニル基、水酸基、チオール基、アルコキシ基、アルキルチオ基、アリールエーテル基、アリールチオエーテル基、アリール基、ヘテロアリール基、ハロゲン、シアノ基、アルデヒド基、カルボニル基、カルボキシル基、エステル基、カルバモイル基、アミノ基、ニトロ基、シリル基、シロキサニル基、ボリル基、スルホ基、ホスフィンオキシド基からなる群より選ばれる。ｋは、１～３の整数である。ｋが２以上である場合、ｒは、それぞれ同じでも異なってもよい。）

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

Further, in the color conversion composition according to the present invention, in the above invention, R ¹ , R ³ , R ⁴ and R ⁶ in the general formula (1) may be the same or different, substituted or unsubstituted is a phenyl group of

Further, in the color conversion composition according to the present invention, in the above invention, R ¹ , R ³ , R ⁴ and R ⁶ in the general formula (1) may be the same or different, substituted or unsubstituted is an alkyl group of

Further, in the color conversion composition according to the present invention, at least one of R ² and R ⁵ in the general formula (1) may be the same or different, and is an electron withdrawing group. , characterized in that

Further, the color conversion composition according to the present invention is characterized in that, in the above invention, R ⁸ and R ⁹ in the general formula (1), which may be the same or different, are fluorine or a cyano group. and

In addition, the color conversion composition according to the present invention is characterized by containing the following luminescent material (a) and luminescent material (b) in the above invention.
Luminescent material (a): A luminescent material that emits light with a peak wavelength of 500 nm or more and 580 nm or less by using excitation light with a wavelength of 400 nm or more and 500 nm or less. A luminescent material that emits light having a peak wavelength of 580 nm or more and 750 nm or less by being excited by at least one of excitation light in the range of 500 nm to 580 nm and excitation light in the range of 500 nm to 580 nm.

A color conversion sheet according to the present invention is characterized by including a color conversion layer comprising a cured layer of the color conversion composition according to any one of the above inventions.

Further, the color conversion sheet according to the present invention includes two or more color conversion layers, and at least one of the two or more color conversion layers is the color conversion composition according to any one of the above inventions. The color conversion layer is a hardened layer of a material.

Further, a light source unit according to the present invention comprises a light source and the color conversion composition according to any one of the above inventions or the color conversion sheet according to any one of the above inventions. Characterized by

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

A display according to the present invention is characterized by comprising the light source unit according to any one of the above inventions.

According to another aspect of the present invention, there is provided a lighting device including the light source unit according to any one of the above-described inventions.

The color conversion composition according to the present invention and the color conversion sheet using the same are effective in achieving both high durability and high luminous efficiency. Since the light source unit, the display, and the lighting device according to the present invention use such a color conversion composition or color conversion sheet, it is possible to achieve both high durability and high brightness.

FIG. 1 is a schematic cross-sectional view showing a first example of a color conversion sheet according to an embodiment of the invention. FIG. 2 is a schematic cross-sectional view showing a second example of the color conversion sheet according to the embodiment of the invention. FIG. 3 is a schematic cross-sectional view showing a third example of the color conversion sheet according to the embodiment of the invention. FIG. 4 is a schematic cross-sectional view showing a fourth example of the color conversion sheet according to the embodiment of the invention. FIG. 5 is a schematic cross-sectional view showing a fifth example of the color conversion sheet according to the embodiment of the invention. FIG. 6 is a schematic cross-sectional view showing a sixth example of the color conversion sheet according to the embodiment of the invention. FIG. 7 is a schematic cross-sectional view showing a seventh example of the color conversion sheet according to the embodiment of the invention. FIG. 8 is a schematic cross-sectional view showing an eighth example of the color conversion sheet according to the embodiment of the invention. FIG. 9 is a diagram illustrating absorption spectra of the compound of Synthesis Example 1 in Examples of the present invention. FIG. 10 is a diagram illustrating the emission spectrum of the compound of Synthesis Example 1 in Examples of the present invention. FIG. 11 is a diagram illustrating the absorption spectrum of the compound of Synthesis Example 2 in Examples of the present invention. FIG. 12 is a diagram illustrating the emission spectrum of the compound of Synthesis Example 2 in Examples of the present invention.

Embodiments of the color conversion composition, the color conversion sheet, the light source unit, the display, and the lighting device according to the present invention will be specifically described below, but the present invention is not limited to the following embodiments. Various modifications can be made according to the purpose and application.

<Color conversion composition>
A color conversion composition according to an embodiment of the present invention is a color conversion composition that converts incident light into light having a longer wavelength than the incident light, and comprises the following components (A) and (B): includes. The (A) component is m kinds of organic light-emitting materials D ₁ , . . . , D _m (m is a natural number). Component (B) is a binder resin having n types of repeating units P ₁ , . . . , P _n (where n is a natural number).

Further, the color conversion composition according to the embodiment of the present invention satisfies the following conditions for the components (A) and (B) contained. _Specifically , for m types of _organic light-emitting materials D ₁ , . Let E _Ah (L) [eV] be the energy level of the empty orbital (LUMO). Regarding n types _of repeating units P _{1 ,} . Let the energy level of (LUMO) be E _Bi (L) [eV]. At this time, E _Ah (H), E _Ah (L), E _Bi (H), and E _Bi (L) satisfy (Equation-1) for components (A) and (B). That is, any organic light emitting material D _h (h is a natural number of 1 or more and m or less) arbitrarily selected from m types of organic light emitting materials D ₁ , . . . , D _m and n types of repeating units P _{1 , . _ _} E _Bi (H) and E _Bi (L) satisfy (Formula-1).
E _Bi (H) ≤ E _Ah (H) ≤ E _Ah (L) ≤ E _Bi (L) (Formula-1)

In the component (A), m is a natural number as described above. This natural number m may be 2 or more. That is, the number of organic light-emitting materials as the component (A) may be one, or two or more. Although the upper limit of the natural number m is not particularly limited, the natural number m is preferably 10 or less from the viewpoint of manufacturing costs. More preferably, the natural number m is 3 or less, and even more preferably, the natural number m is 1 or 2.

In the component (B), n is a natural number as described above. This natural number n may be 2 or more. That is, the repeating unit of the binder resin as the component (B) may be of one type or of two or more types. Although the upper limit of the natural number n is not particularly limited, the natural number n is preferably 20 or less from the viewpoint of ease of manufacture. More preferably, the natural number n is 10 or less.

Moreover, in the component (B), the repeating units P _{1 ,} . _For example, the repeating units P ₁ , .

Here, in the present invention, the HOMO and LUMO energy levels of the light-emitting material and the HOMO and LUMO energy levels of the repeating units of the binder resin are calculated by the density general function (DFT) method. In the present invention, BIOVIA Materials Studio 2016 manufactured by BIOVIA was used as molecular orbital calculation software to perform structure optimization and energy calculation of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). The luminescent material referred to here is a luminescent material contained in the color conversion composition according to the embodiment of the present invention. Examples of such light-emitting materials include m types of organic light-emitting materials as the component (A).

The energy level of the HOMO of the organic light-emitting material and the energy level of the HOMO of the repeating unit of the binder resin do not satisfy the relationship of (Formula-1), that is, the energy level of the HOMO of the organic light-emitting material is the same as that of the repeating unit of the binder resin. When the energy level is lower than the HOMO of the unit, the electron moves from the HOMO of the repeating unit of the binder resin to the HOMO vacancy of the organic light-emitting material generated when the organic light-emitting material is excited by excitation light and the electron transitions. This inhibits the luminescence process. This movement of electrons is movement from a high energy level to a low energy level, and occurs with the stabilization of the system as the driving force. If the emission process is inhibited by this electron transfer, electrons that have transitioned to a higher energy level due to excitation lose energy obtained by absorption of excitation light due to non-radiative transition. As a result, the luminous efficiency of the organic luminescent material in the color conversion composition becomes low. Furthermore, since the organic light-emitting material undergoes a non-radiative transition process with high energy and a long life, it is highly likely that the organic light-emitting material undergoes various reactions with surrounding components and is degraded or decomposed. This also results in poor durability of the color conversion composition.

On the other hand, the energy level of the HOMO of the organic light-emitting material and the energy level of the HOMO of the repeating unit of the binder resin satisfy the relationship of (Formula-1), that is, the energy level of the HOMO of the organic light-emitting material is that of the binder resin. When the energy level is higher than the energy level of the HOMO of the repeating unit, the electron transfer from the HOMO of the repeating unit of the binder resin to the HOMO of the organic light-emitting material tends to destabilize the system, and thus is unlikely to occur. Therefore, the luminescence process is less likely to be disturbed. As a result, the luminous efficiency of the organic light emitting material in the color conversion composition is not lowered. Furthermore, since the organic light-emitting material does not pass through a long-lived high-energy state, reactions with surrounding components are also suppressed. As a result, the durability of the color conversion composition does not deteriorate.

When the energy level of the HOMO of the organic light-emitting material and the energy level of the HOMO of the repeating unit of the binder resin are extremely close, even if the relationship of (Formula-1) is normally satisfied, due to factors such as heat, There is a possibility that the energy level relationship will temporarily fluctuate, resulting in electron transfer from the HOMO of the repeating unit of the binder resin to the HOMO of the organic light-emitting material. Therefore, it is preferable that there is some difference between the HOMO energy level of the organic light-emitting material and the HOMO energy level of the repeating unit of the binder resin. The magnitude of this energy level difference is preferably 0.05 eV or more. That is, for the components (A) and (B), it is preferable that the above E _Ah (H) and E _Bi (H) satisfy (Formula-2).
E _Bi (H) ≤ E _Ah (H) - 0.05 (Formula-2)

The magnitude of the energy level difference described above is preferably larger. For example, the magnitude of the energy level difference described above is more preferably 0.07 eV or more, and even more preferably 0.10 eV or more.

The energy level of the LUMO of the organic light-emitting material and the energy level of the LUMO of the repeating unit of the binder resin do not satisfy the relationship of (Formula-1), that is, the energy level of the LUMO of the organic light-emitting material is the repetition of the binder resin. When the energy level is higher than the LUMO of the unit, when the organic light-emitting material is excited by the excitation light and the electron transitions, the electron moves from the excitation level of the organic light-emitting material to the LUMO of the repeating unit of the binder resin. In this case, the energy obtained by absorption of the excitation light is lost by non-radiative transitions rather than by luminescence processes. As a result, the luminous efficiency of the organic luminescent material in the color conversion composition becomes low. Furthermore, the organic light-emitting material undergoes a high-energy, long-lived non-radiative transition process, and thus has a high probability of being denatured or decomposed due to various reactions with surrounding components. This also results in poor durability of the color conversion composition.

On the other hand, the energy level of the LUMO of the organic light emitting material and the energy level of the LUMO of the repeating unit of the binder resin satisfy the relationship of (Formula-1), that is, the energy level of the LUMO of the organic light emitting material is that of the binder resin If the energy level is lower than the energy level of the LUMO of the repeating unit, the electron transfer from the excitation level of the organic light-emitting material to the LUMO of the repeating unit of the binder resin tends to destabilize the system, and thus is unlikely to occur. Therefore, the luminescence process is less likely to be disturbed. As a result, the luminous efficiency of the organic light emitting material in the color conversion composition is not lowered. Furthermore, since the organic light-emitting material does not pass through a long-lived high-energy state, reactions with surrounding components are also suppressed. As a result, the durability of the color conversion composition does not deteriorate.

When the energy level of the LUMO of the organic light-emitting material and the energy level of the LUMO of the repeating unit of the binder resin are extremely close, even if the relationship of (Formula-1) is normally satisfied, the energy level may change due to factors such as heat. The positional relationship may change temporarily, causing electron transfer from the excited level of the organic light-emitting material to the LUMO of the repeating unit of the binder resin. Therefore, it is preferable that there is some difference between the LUMO energy level of the organic light-emitting material and the LUMO energy level of the repeating unit of the binder resin. The magnitude of this energy level difference is preferably 0.05 eV or more. That is, for the components (A) and (B), the above-mentioned E _Ah (L) and E _Bi (L) preferably satisfy (Formula-3).
E _Ah (L) + 0.05 ≤ E _Bi (L) (Formula-3)

Furthermore, the inventors have found that the _HOMO energy levels of m kinds of organic light-emitting materials D ₁ , . It was found to exhibit durability. Specifically, for the component (A), when the HOMO energy level of the organic light-emitting material (that is, E _Ah (H) described above) satisfies either (Formula-4) or (Formula-5), the organic Oxidative deterioration of the light-emitting material due to oxygen (especially singlet oxygen) is suppressed, thereby suppressing deterioration and decomposition of the organic light-emitting material. As a result, high durability of the color conversion composition can be obtained.
E _Ah (H) ≤ -5.00 (Formula-4)
E _Ah (H)≧−4.50 (Formula-5)

In component (A), when the HOMO energy level of the organic light-emitting material satisfies (Formula-4), the energy level is preferably lower. For example, the energy level is more preferably −5.20 eV or less, still more preferably −5.40 eV or less, and particularly preferably −5.60 eV or less.

Further, in the component (A), when the HOMO energy level of the organic light-emitting material satisfies (Formula-5), the energy level is preferably higher. For example, this energy level is more preferably -4.40 eV or higher, and still more preferably -4.30 eV or higher.

In the component (A), from the viewpoint of improving the durability of the color conversion composition, at least one of _the m types of organic light-emitting materials D ₁ , . is preferred.
E _Ah (H) ≤ -5.00 (Formula-6)

Moreover, the color conversion composition according to the embodiment of the present invention preferably contains the following component (C) in addition to the components (A) and (B) described above. Component (C) is q kinds of organic compounds Q ₁ , . . . , Q _q (where q is a natural number). Moreover, when the color conversion composition according to the embodiment of the present invention contains the component (C), it preferably satisfies the following conditions. Specifically, an arbitrary organic compound Q _j (j is a natural number of 1 or more and _q or less) arbitrarily selected from q kinds of organic compounds Q ₁ , . When the energy level of the occupied molecular orbital (HOMO) is E _Cj (H) [eV] and the energy level of the lowest unoccupied molecular orbital (LUMO) is E _Cj (L) [eV], the (A) component and ( C) component, that is, an arbitrary organic light-emitting material D _h (h is a natural number of 1 or more and m or less) arbitrarily selected from m kinds of organic light-emitting materials D ₁ , . . . , D _m and q kinds All possible combinations with an arbitrary organic compound Q j (j is a natural number of 1 or more and q or less) arbitrarily selected from organic compounds Q 1 , ..., Q q of E _Ah ( _H ) _{, E Ah} (L), E _Cj (H), and E _Cj (L) preferably satisfy (Equation-7). In the color conversion composition, between the HOMO and LUMO energy levels of the organic light-emitting material as the (A) component and the HOMO and LUMO energy levels of the organic compound as the (C) component, (Formula-7) When the relationship of is satisfied, both high luminance and high durability of the color conversion composition can be achieved.
E _Cj (H) ≤ E _Ah (H) ≤ E _Ah (L) ≤ E _Cj (L) (Formula-7)

The HOMO energy level of the organic light-emitting material and the HOMO energy level of the organic compound do not satisfy the relationship of (Formula-7), that is, the HOMO energy level of the organic light-emitting material is equal to the HOMO energy level of the organic compound. When the organic light-emitting material is excited by excitation light and electrons transition, electrons move from the HOMO of the organic compound to vacancies in the HOMO of the organic light-emitting material, resulting in inhibition of the light emission process. . This movement of electrons is movement from a high energy level to a low energy level, and occurs with the stabilization of the system as the driving force. If the emission process is inhibited by this electron transfer, electrons that have transitioned to a higher energy level due to excitation lose energy obtained by absorption of excitation light due to non-radiative transition. As a result, the luminous efficiency of the organic luminescent material in the color conversion composition becomes low. Furthermore, since the organic light-emitting material undergoes a non-radiative transition process with high energy and a long life, it is highly likely that the organic light-emitting material undergoes various reactions with surrounding components and is degraded or decomposed. This also results in poor durability of the color conversion composition.

On the other hand, the HOMO energy level of the organic light-emitting material and the HOMO energy level of the organic compound satisfy the relationship of (Formula-7), that is, the HOMO energy level of the organic light-emitting material is equal to the HOMO energy of the organic compound. When it is at or above the level, the electron transfer from the HOMO of the organic compound to the HOMO of the organic light-emitting material is a transfer in the direction of destabilizing the system, so that it is difficult to occur. Therefore, the luminescence process is less likely to be disturbed. As a result, the luminous efficiency of the organic light emitting material in the color conversion composition is not lowered. Furthermore, since the organic light-emitting material does not pass through a long-lived high-energy state, reactions with surrounding components are also suppressed. As a result, the durability of the color conversion composition does not deteriorate.

The energy level of the LUMO of the organic light-emitting material and the energy level of the LUMO of the organic compound do not satisfy the relationship of (Formula-7), that is, the energy level of the LUMO of the organic light-emitting material is equal to the energy level of the LUMO of the organic compound. When the organic light-emitting material is excited by excitation light and electrons transition, electrons move from the excitation level of the organic light-emitting material to the LUMO of the organic compound. In this case, the energy obtained by absorption of the excitation light is lost by non-radiative transitions rather than by luminescence processes. As a result, the luminous efficiency of the organic luminescent material in the color conversion composition becomes low. Furthermore, the organic light-emitting material undergoes a high-energy, long-lived non-radiative transition process, and thus has a high probability of being denatured or decomposed due to various reactions with surrounding components. This also results in poor durability of the color conversion composition.

On the other hand, the energy level of the LUMO of the organic light-emitting material and the energy level of the LUMO of the organic compound satisfy the relationship of (Formula-7), that is, the energy level of the LUMO of the organic light-emitting material is the energy of the LUMO of the organic compound. When it is below the level, the electron transfer from the excitation level of the organic light-emitting material to the LUMO of the organic compound is a transfer in the direction of destabilizing the system, and therefore is unlikely to occur. Therefore, the luminescence process is less likely to be disturbed. As a result, the luminous efficiency of the organic light emitting material in the color conversion composition is not lowered. Furthermore, since the organic light-emitting material does not pass through a long-lived high-energy state, reactions with surrounding components are also suppressed. As a result, the durability of the color conversion composition does not deteriorate.

In the (C) component, q is a natural number as described above. This natural number q may be 2 or more. That is, the number of organic compounds as the component (C) may be one, or two or more. Although the upper limit of the natural number q is not particularly limited, the natural number q is preferably 20 or less from the viewpoint of ease of manufacture. More preferably, the natural number q is 10 or less.

By curing the color conversion composition according to the embodiment of the present invention, a color conversion layer comprising a cured layer of this color conversion composition can be formed. A color conversion sheet including such a color conversion layer is an example of the color conversion sheet according to the embodiment of the present invention, and achieves both high durability and high luminous efficiency. Therefore, when the color conversion sheet is used for a light source unit, a display (eg liquid crystal display) and a lighting device (eg LED lighting), it is possible to achieve both high durability and high brightness.

Further, when the color conversion sheet according to the embodiment of the present invention includes two or more color conversion layers, at least one of the two or more color conversion layers is the color conversion sheet according to the embodiment of the present invention. The color conversion layer is preferably a cured layer of the composition. In the color conversion sheet in this case, it is more preferable that all of these two or more color conversion layers are color conversion layers made of a cured layer of the color conversion composition according to the embodiment of the present invention.

<(A) Component: Organic Light Emitting Material>
The color conversion composition according to the embodiment of the present invention contains m kinds of organic light-emitting materials D ₁ , . . . , D _m (m is a natural number) as the component (A). Here, the luminescent material in the present invention means a material that emits light having a wavelength different from that of the irradiated light. An organic light-emitting material is an organic light-emitting material.

In order to achieve highly efficient color conversion, the luminescent material is preferably a material exhibiting luminescent properties with a high emission quantum yield. In general, the luminescent material includes known luminescent materials such as inorganic phosphors, fluorescent pigments, fluorescent dyes, and quantum dots. Materials are preferred.

Examples of the organic light-emitting material include those shown below. For example, naphthalene, anthracene, phenanthrene, pyrene, chrysene, naphthacene, triphenylene, perylene, fluoranthene, fluorene, compounds having condensed aryl rings such as indene, derivatives thereof, and the like are suitable organic light-emitting materials. Furan, pyrrole, thiophene, silole, 9-silafluorene, 9,9'-spirobisilafluorene, benzothiophene, benzofuran, indole, dibenzothiophene, dibenzofuran, imidazopyridine, phenanthroline, pyridine, pyrazine, naphthyridine, quinoxaline, Compounds having a heteroaryl ring such as pyrrolopyridine, derivatives thereof, borane derivatives, and the like are examples of suitable organic light-emitting materials.

Also, 1,4-distyrylbenzene, 4,4'-bis(2-(4-diphenylaminophenyl)ethenyl)biphenyl, 4,4'-bis(N-(stilben-4-yl)-N-phenyl Stilbene derivatives such as amino)stilbene, aromatic acetylene derivatives, tetraphenylbutadiene derivatives, aldazine derivatives, pyrromethene derivatives, diketopyrrolo[3,4-c]pyrrole derivatives and the like are suitable organic light-emitting materials. In addition, coumarin derivatives such as coumarin 6, coumarin 7 and coumarin 153; azole derivatives such as imidazole, thiazole, thiadiazole, carbazole, oxazole, oxadiazole and triazole and their metal complexes; cyanine compounds such as indocyanine green; Xanthene-based compounds such as eosin and rhodamine, thioxanthene-based compounds, and the like are examples of suitable organic light-emitting materials.

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

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

Moreover, as the organic light-emitting material, a compound having a coordinate bond is preferable from the viewpoint of solubility and diversity of molecular structures. A boron-containing compound such as a boron fluoride complex is also preferable in that the half width is small and highly efficient light emission is possible.

Among these compounds, pyrromethene derivatives can be preferably used because they provide a high emission quantum yield and have good durability. More preferably, it is a compound represented by general formula (1). In the color conversion composition according to the embodiment of the present invention, component (A) preferably contains at least a compound represented by general formula (1).

In general formula (1), X is C—R ⁷ or N. R ¹ to R ⁹ may be the same or different, and may be hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, aryl ether group, arylthioether group, aryl group, heteroaryl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, boryl group, It is selected from a sulfo group, a phosphine oxide group, and condensed rings and aliphatic rings formed between adjacent substituents.

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

In all the above groups, substituents when substituted include alkyl groups, cycloalkyl groups, heterocyclic groups, alkenyl groups, cycloalkenyl groups, alkynyl groups, hydroxyl groups, thiol groups, alkoxy groups, and alkylthio groups. , aryl ether group, arylthioether group, aryl group, heteroaryl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, boryl group , a sulfo group, and a phosphine oxide group are preferred, and more preferred specific substituents are preferred in the description of each substituent. In addition, these substituents may be further substituted with the above substituents.

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

Among all the above groups, alkyl group means, for example, saturated aliphatic hydrocarbon such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group and tert-butyl group. represents a group, which may or may not have substituents. Additional substituents when substituted are not particularly limited, and include, for example, alkyl groups, halogens, aryl groups, heteroaryl groups, etc. This point is also common to the following description. The number of carbon atoms in the alkyl group is not particularly limited, but is preferably in the range of 1 to 20, more preferably 1 to 8, from the viewpoint of availability and cost.

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

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

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

A cycloalkenyl group is, for example, an unsaturated alicyclic hydrocarbon group containing a double bond such as a cyclopentenyl group, a cyclopentadienyl group, a cyclohexenyl group, and the like, even if it has a substituent. It does not have to be.

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

An alkoxy group is, for example, a functional group in which an aliphatic hydrocarbon group is bonded via an ether bond such as a methoxy group, an ethoxy group, a propoxy group, and the aliphatic hydrocarbon group has a substituent. does not have to be 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 substituted 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.

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

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

An aryl group includes, for example, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a benzofluorenyl group, a dibenzofluorenyl group, a phenanthryl group, anthracenyl group, a benzophenanthryl group, and a benzoanthracene. It represents an aromatic hydrocarbon group such as a nyl group, a chrysenyl group, a pyrenyl group, a fluoranthenyl group, a triphenylenyl group, a benzofluoranthenyl group, a dibenzoanthracenyl group, a perylenyl group, and a helicenyl group. Among them, 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 6 or more and 40 or less, more preferably 6 or more and 30 or less.

When R ¹ to R ⁹ are substituted or unsubstituted aryl groups, the aryl group is preferably a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, an anthracenyl group, and a phenyl group or a biphenyl group. group, terphenyl group and naphthyl group are more preferable. Phenyl group, biphenyl group and terphenyl group are more preferable, and phenyl group is particularly preferable.

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

The heteroaryl group includes, for example, pyridyl group, furanyl group, thienyl group, quinolinyl group, isoquinolinyl group, pyrazinyl group, pyrimidyl group, pyridazinyl group, triazinyl group, napthyridinyl 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 non-carbon atoms such as dihydroindenocarbazolyl, benzoquinolinyl, acridinyl, dibenzoacridinyl, benzimidazolyl, imidazopyridyl, benzoxazolyl, benzothiazolyl, phenanthrolinyl groups represents a cyclic aromatic group having one or more in the ring. However, the naphthyridinyl group is any of a 1,5-naphthyridinyl group, a 1,6-naphthyridinyl group, a 1,7-naphthyridinyl group, a 1,8-naphthyridinyl group, a 2,6-naphthyridinyl group and a 2,7-naphthyridinyl group. or 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 to 40, more preferably in the range of 2 to 30.

When R ¹ to R ⁹ are substituted or unsubstituted heteroaryl groups, heteroaryl groups include pyridyl, furanyl, thienyl, quinolinyl, pyrimidyl, triazinyl, benzofuranyl, benzothienyl, and indolyl. group, dibenzofuranyl group, dibenzothienyl group, carbazolyl group, benzimidazolyl group, imidazopyridyl group, benzoxazolyl group, benzothiazolyl group and phenanthrolinyl group are preferred, and pyridyl group, furanyl group, thienyl group and quinolinyl group are preferred. more preferred. A pyridyl group is particularly preferred.

When each substituent is further substituted with a heteroaryl group, the heteroaryl group includes pyridyl, furanyl, thienyl, quinolinyl, pyrimidyl, triazinyl, benzofuranyl, benzothienyl, indolyl, dibenzo Furanyl group, dibenzothienyl group, carbazolyl group, benzimidazolyl group, imidazopyridyl group, benzoxazolyl group, benzothiazolyl group and phenanthrolinyl group are preferred, and pyridyl group, furanyl group, thienyl group and quinolinyl group are more preferred. A pyridyl group is particularly preferred.

Halogen denotes an atom selected from fluorine, chlorine, bromine and iodine. A carbonyl group, a carboxyl group, an ester group, and a carbamoyl group may or may not have a substituent. Examples of substituents include alkyl groups, cycloalkyl groups, aryl groups, and heteroaryl groups, and these substituents may be further substituted.

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

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

A siloxanyl group is, for example, a silicon compound group via an ether bond such as a trimethylsiloxanyl group. Substituents on silicon may be further substituted. A boryl group is a substituted or unsubstituted boryl group. The boryl group may or may not have a substituent, and examples of substituents when substituted include an aryl group, a heteroaryl group, a linear alkyl group, a branched alkyl group, and an aryl ether group. , an alkoxy group, a hydroxyl group, and the like. Among them, an aryl group and an aryl ether group are preferred. A sulfo group is a substituted or unsubstituted sulfo group. The sulfone group may or may not have a substituent, and examples of substituents in the case of substitution include an aryl group, a heteroaryl group, a linear alkyl group, a branched alkyl group, and an aryl ether group. , an alkoxy group, and the like. Among them, straight-chain alkyl groups and aryl groups are preferred. A phosphine oxide group is a group represented by -P(=O)R ¹⁰ R ¹¹ . R ¹⁰ R ¹¹ is selected from the same group as R ¹ to R ⁹ .

A condensed ring and an aliphatic ring formed between adjacent substituents are any two adjacent substituents (for example, R ¹ and R ² in general formula (1)) that are bonded to each other to form a conjugated or non-conjugated ring. to form a cyclic skeleton of Constituent elements of such condensed rings and aliphatic rings may contain, in addition to carbon, an element selected from nitrogen, oxygen, sulfur, phosphorus and silicon. In addition, these condensed rings and aliphatic rings may be condensed with another ring.

Since the compound represented by the general formula (1) exhibits a high emission quantum yield and a narrow half width of the emission spectrum, it can achieve both efficient color conversion and high color purity. Furthermore, the compound represented by the general formula (1) can have various properties such as luminous efficiency, color purity, thermal stability, photostability and dispersibility by introducing appropriate substituents at appropriate positions. and physical properties can be adjusted. For example, at ^{least one of R 1 , R 3 , R 4 and R 6 is a substituted} or unsubstituted ^alkyl group or a substituted or unsubstituted , a substituted or unsubstituted heteroaryl group exhibits better thermal and light stability.

When at least one of R ¹ , R ³ , R ⁴ and R ⁶ is a substituted or unsubstituted alkyl group, the alkyl group includes methyl group, ethyl group, n-propyl group, isopropyl group and n-butyl group. , sec-butyl, tert-butyl, pentyl and hexyl groups are preferred. Further, the alkyl group is preferably a methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, sec-butyl group or tert-butyl group from the viewpoint of excellent thermal stability. Further, from the viewpoint of preventing concentration quenching and improving the emission quantum yield, the alkyl group is more preferably a sterically bulky tert-butyl group. Moreover, a methyl group is preferably used as the alkyl group from the viewpoint of ease of synthesis and availability of raw materials.

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

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

All of R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and when they are substituted or unsubstituted alkyl groups, they are preferred because they have good solubility in binder resins and solvents. In this case, the alkyl group is preferably a methyl group from the viewpoint of ease of synthesis and availability of raw materials.

^{Better thermal stability and} It is preferred because it exhibits photostability. In this case, all of R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and are more preferably substituted or unsubstituted aryl groups.

Although there are substituents that improve multiple properties, only a limited number of substituents exhibit sufficient performance in all respects. In particular, it is difficult to achieve both high luminous efficiency and high color purity. Therefore, by introducing a plurality of types of substituents into the compound represented by the general formula (1), it is possible to obtain a compound having well-balanced emission characteristics, color purity, and the like.

In particular, when R ¹ , R ³ , R ⁴ and R ⁶ may all be the same or different and are substituted or unsubstituted aryl groups, for example R ¹ ≠R ⁴ , R ³ ≠R ⁶ , R It is preferable to introduce a plurality of types of substituents such as ¹ ≠R ³ or R ⁴ ≠R ⁶ . Here, "≠" indicates groups with different structures. For example, R ¹ ≠R ⁴ indicates that R ¹ and R ⁴ are groups with different structures. By introducing a plurality of types of substituents as described above, an aryl group that affects color purity and an aryl group that affects luminous efficiency can be introduced at the same time, enabling fine adjustment.

Among them, R ¹ ≠R ³ or R ⁴ ≠R ⁶ is preferable from the viewpoint of improving luminous efficiency and color purity in a well-balanced manner. In this case, one or more aryl groups that affect the color purity are introduced into each of the pyrrole rings on both sides of the compound represented by the general formula (1), and aryl groups that affect the luminous efficiency are placed at other positions. Both of these properties can be maximized by the ability to introduce groups. Further, when R ¹ ≠R ³ or R ⁴ ≠R ⁶ , it is more preferable that R ¹ =R ⁴ and R ³ =R ⁶ from the viewpoint of improving both heat resistance and color purity.

An aryl group substituted with an electron-donating group is preferred as the aryl group that mainly affects color purity. An electron-donating group is an atomic group that donates electrons to a substituted atomic group by an inductive effect or a resonance effect in the theory of organic electrons. Examples of the electron-donating group include those having a negative Hammett's rule substituent constant (σp (para)). Hammett's rule substituent constant (σp (para)) can be quoted from Kagaku Handan Basic Edition 5th Revised Edition (page II-380).

Specific examples of electron donating groups include alkyl groups (σp of methyl group: -0.17), alkoxy groups (σp of methoxy group: -0.27), amino groups (σp of _-NH2 : - 0.66) and the like. In particular, an alkyl group having 1 to 8 carbon atoms or an alkoxy group having 1 to 8 carbon atoms is preferable, and a methyl group, an ethyl group, a tert-butyl group and a methoxy group are more preferable. From the viewpoint of dispersibility, a tert-butyl group and a methoxy group are particularly preferable, and when these are used as the electron-donating groups, in the compound represented by the general formula (1), quenching due to aggregation between molecules is prevented. be able to. The substitution position of the substituent is not particularly limited, but since it is necessary to suppress the torsion of the bond in order to increase the photostability of the compound represented by the general formula (1), meta It is preferred to bind at the or para position. On the other hand, as the aryl group that mainly affects the luminous efficiency, an aryl group having a bulky substituent such as a tert-butyl group, an adamantyl group, or a methoxy group is preferable.

R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and when they are substituted or unsubstituted aryl groups, R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different. A substituted or unsubstituted phenyl group is preferred. At this time, R ¹ , R ³ , R ⁴ and R ⁶ are more preferably selected from Ar-1 to Ar-6 below.

Moreover, in the general formula (1), X is preferably C—R ⁷ from the viewpoint of photostability. When X is C—R ⁷ , the substituent R ⁷ greatly affects the durability of the compound represented by the general formula (1), that is, the decrease in emission intensity of this compound over time. Specifically, when R ⁷ is hydrogen, this site is highly reactive and easily reacts with moisture and oxygen in the air. This causes decomposition of the compound represented by general formula (1). In addition, when ^R7 is a substituent such as an alkyl group having a large degree of freedom of movement of the molecular chain, the reactivity certainly decreases, but the compounds do not interact with each other in the color conversion composition or the color conversion sheet. Aggregates over time, resulting in a decrease in emission intensity due to concentration quenching. Therefore, R ⁷ is preferably a group that is rigid, has a small degree of freedom of movement and is unlikely to cause aggregation. Specifically, a substituted or unsubstituted aryl group or a substituted or unsubstituted heteroaryl group Either is preferred.

X is C—R ⁷ and R ⁷ is preferably a substituted or unsubstituted aryl group from the viewpoints of providing a higher emission quantum yield, less thermal decomposition, and photostability. As the aryl group, a phenyl group, a biphenyl group, a terphenyl group, a naphthyl group, a fluorenyl group, a phenanthryl group, and an anthracenyl group are preferable from the viewpoint of not impairing the emission wavelength.

Furthermore, in order to increase the photostability of the compound represented by the general formula (1), it is necessary to moderately suppress the torsion of the carbon-carbon bond between R ⁷ and the pyrromethene skeleton. This is because if the torsion is excessively large, the reactivity to excitation light increases and the photostability decreases. From such a viewpoint, R ⁷ is preferably a substituted or unsubstituted phenyl group, a substituted or unsubstituted biphenyl group, a substituted or unsubstituted terphenyl group, a substituted or unsubstituted naphthyl group, and a substituted or unsubstituted A phenyl group, a substituted or unsubstituted biphenyl group, and a substituted or unsubstituted terphenyl group are more preferred. A substituted or unsubstituted phenyl group is particularly preferred.

Also, R ⁷ is preferably a reasonably bulky substituent. Molecular aggregation can be prevented by ^R7 having a certain degree of bulkiness. As a result, the luminous efficiency and durability of the compound represented by formula (1) are further improved.

More preferable examples of such bulky substituents include the structure of R ⁷ represented by the following general formula (2). That is, R ⁷ is preferably a group represented by general formula (2).

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

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

In addition, from the viewpoint of controlling the fluorescence wavelength and absorption wavelength and improving compatibility with solvents, r is preferably a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, or halogen. , methyl group, ethyl group, tert-butyl group and methoxy group are more preferred. From the viewpoint of dispersibility, r is particularly preferably a tert-butyl group or a methoxy group. A tert-butyl group or a methoxy group for r is more effective in preventing quenching due to aggregation between molecules.

As another aspect of the compound represented by formula (1), at least one of R ¹ to R ⁷ is preferably an electron withdrawing group. In particular, (1) at least one of R ¹ -R ⁶ is an electron withdrawing group, (2) R ⁷ is an electron withdrawing group, or (3) at least one of R ¹ -R ⁶ is an electron withdrawing group and ^R7 is an electron withdrawing group. By introducing an electron-withdrawing group into the pyrromethene skeleton of the above compound, the electron density of the pyrromethene skeleton can be significantly reduced. This further improves the stability of the compound against oxygen, and as a result, the durability of the compound can be further improved.

An electron-withdrawing group, also called an electron-accepting group, is an atomic group that attracts electrons from a substituted atomic group by an inductive effect or a resonance effect in organic electronic theory. Examples of the electron-withdrawing group include those having a positive value as the substituent constant (σp (para)) of Hammett's rule. Hammett's rule substituent constant (σp (para)) can be quoted from Kagaku Handan Basic Edition 5th Revised Edition (page II-380). Although there are also examples of phenyl groups having positive values as described above, electron-withdrawing groups in the present invention do not include phenyl groups.

Examples of electron withdrawing groups include -F (σp: +0.06), -Cl (σp: +0.23), -Br (σp: +0.23), -I (σp: +0.18), —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), — CF ₃ (σp: +0.50), —SO ₂ R ¹² (σp: +0.69 when R ¹² is a methyl group), —NO ₂ (σp: +0.81), and the like. Each R ¹² is independently a hydrogen atom, a substituted or unsubstituted aromatic hydrocarbon group having 6 to 30 ring-forming carbon atoms, a substituted or unsubstituted heterocyclic group having 5 to 30 ring-forming atoms, a substituted or unsubstituted It 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 those described above.

Preferred electron-withdrawing groups include fluorine, fluorine-containing aryl groups, fluorine-containing heteroaryl groups, fluorine-containing alkyl groups, substituted or unsubstituted acyl groups, substituted or unsubstituted ester groups, substituted or unsubstituted amide groups, A substituted or unsubstituted sulfonyl group or cyano group can be mentioned. This is because they are difficult to decompose chemically.

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

In general formula (1), ^R2 and ^R5 are preferably hydrogen, an alkyl group, or an aryl group from the viewpoint of thermal stability. Among them, hydrogen is more preferable from the viewpoint that it is easy to obtain a narrow half width in the emission spectrum.

Moreover, from the viewpoint of improving durability, at least one of R ² and R ⁵ may be the same or different, and is preferably an electron-withdrawing group. Above all, at least one of R ² and R ⁵ , which may be the same or different, is a substituted or unsubstituted ester group, because durability can be improved without reducing color purity. ,preferable. In particular, both ^R2 and ^R5 , which may be the same or different, are particularly preferably substituted or unsubstituted ester groups from the viewpoint of improving durability.

^R8 and ^R9 are preferably an alkyl group, an aryl group, a heteroaryl group, 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 more preferably fluorine, fluorine-containing aryl groups, or cyano groups because they are stable to excitation light and provide a higher emission quantum yield.

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

By lowering the electron density on the boron atom in the compound represented by the general formula (1), the stability of this compound against oxygen is further improved, and as a result, the durability of this compound can be further improved. Therefore, R ⁸ and R ⁹ may be the same or different, and are more preferably fluorine or cyano groups.

It is preferred that at least one of R ⁸ and R ⁹ is a cyano group because the electron density on the boron atom is further reduced. It is particularly preferred that both R ⁸ and R ⁹ are cyano groups. At least one of R ⁸ and R ⁹ is also preferably fluorine from the viewpoint of obtaining a high emission quantum yield. From the viewpoint of ease of synthesis, both R ⁸ and R ⁹ are more preferably fluorine.

As a first preferred example of the compound represented by the general formula (1), 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, X is C—R ⁷ and R ⁷ is a group represented by general formula (2). In this case, R ⁷ is particularly preferably a group represented by general formula (2) in which r is a substituted or unsubstituted phenyl group.

Further, as a second preferred example of the compound represented by the general formula (1), all of R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and the above-mentioned Ar-1 to Ar -6, and further, X is C—R ⁷ and R ⁷ is a group represented by general formula (2). In this case, R ⁷ is more preferably a group represented by general formula (2) in which r is a tert-butyl group or a methoxy group, and is represented by general formula (2) in which r is a methoxy group. is particularly preferred.

Further, as a third preferable example of the compound represented by the general formula (1), all of R ¹ , R ³ , R ⁴ and R ⁶ may be the same or different, and a substituted or unsubstituted alkyl group and R ² and R ⁵ may be the same or different and are substituted or unsubstituted ester groups, and X is C—R ⁷ and R ⁷ is represented by the general formula (2 ) is a group represented by In this case, R ⁷ is particularly preferably a group represented by general formula (2) in which r is a substituted or unsubstituted phenyl group.

Further, as a fourth preferred example of the compound represented by the general formula (1), R ¹ , R ³ , R ⁴ and R ⁶ may all be the same or different, and the above-mentioned Ar-1 to Ar -6, R ² and R ⁵ , which may be the same or different, are substituted or unsubstituted ester groups, and X is C—R ⁷ , and R ⁷ is represented by the general formula The case where it is group represented by (2) is mentioned. In this case, R ⁷ is more preferably a group represented by general formula (2) in which r is a tert-butyl group or a methoxy group, and is represented by general formula (2) in which r is a methoxy group. is particularly preferred.

Examples of the compounds represented by formula (1) are shown below, but the compounds are not limited thereto.

The compound represented by the general formula (1) can be synthesized, for example, by the methods described in JP-A-8-509471 and JP-A-2000-208262. That is, the target pyrromethene-based metal complex is obtained by reacting the pyrromethene compound and the metal salt in the presence of a base.

For the synthesis of pyrromethene-boron fluoride complexes, see J. Am. Org. Chem. , vol. 64, No. 21, pp. 7813-7819 (1999), Angew. Chem. , Int. Ed. Engl. , vol. 36, pp. 1333-1335 (1997), etc., the compound represented by the general formula (1) can be synthesized. For example, after heating a compound represented by the following general formula (3) and a compound represented by the general formula (4) in the presence of phosphorus oxychloride in 1,2-dichloroethane, the following general formula (5) A method of obtaining a compound represented by general formula (1) by reacting the represented compound in 1,2-dichloroethane in the presence of triethylamine can be mentioned. However, the invention is not limited to this. Here, R ¹ to R ⁹ are the same as described above. J represents halogen.

Furthermore, when introducing an aryl group or a heteroaryl group, a method of forming a carbon-carbon bond using a coupling reaction between a halogenated derivative and a boronic acid or boronic acid ester derivative can be mentioned. , but not limited to. Similarly, when introducing an amino group or a carbazolyl group, for example, a method of forming a carbon-nitrogen bond using a coupling reaction between a halogenated derivative and an amine or a carbazole derivative in the presence of a metal catalyst such as palladium. However, the present invention is not limited to this.

The color conversion composition according to the embodiment of the present invention can contain other compounds, if necessary, in addition to the compound represented by formula (1). For example, in order to further increase the efficiency of energy transfer from excitation light to the compound represented by general formula (1), an assist dopant such as rubrene may be contained. Further, when it is desired to add a luminescent color other than the luminescent color of the compound represented by the general formula (1), a desired organic luminescent material, for example, an organic luminescent material such as a coumarin-based dye or a rhodamine-based dye can be added. can. In addition to these organic light-emitting materials, it is also possible to combine and add known light-emitting materials such as inorganic phosphors, fluorescent pigments, fluorescent dyes, and quantum dots.

Examples of organic light-emitting materials other than the compound represented by formula (1) are shown below, but the present invention is not particularly limited to these.

The color conversion composition according to the embodiment of the present invention is a luminescent material (hereinafter referred to as " It preferably contains a luminescent material (a)”). Hereinafter, luminescence observed in a region with a peak wavelength of 500 nm or more and 580 nm or less will be referred to as "green luminescence".

Further, the color conversion composition according to the embodiment of the present invention is excited by at least one of the excitation light having a wavelength of 400 nm or more and 500 nm or less and the excitation light having a wavelength of 500 nm or more and 580 nm or less. It preferably contains a light-emitting material exhibiting light emission observed in a wavelength range of 580 nm or more and 750 nm or less (hereinafter referred to as "light-emitting material (b)"). Hereinafter, luminescence observed in a region with a peak wavelength of 580 nm or more and 750 nm or less will be referred to as "red luminescence".

In general, the higher the energy of the excitation light, the more likely it is to cause decomposition of the material. However, excitation light with a wavelength in the range of 400 nm or more and 500 nm or less has relatively small excitation energy. Therefore, light emission with good color purity can be obtained without causing decomposition of the light emitting material in the color conversion composition.

The color conversion composition according to the embodiment of the present invention may contain either one of the luminescent material (a) and the luminescent material (b), or may contain both of them. Moreover, the said light emitting material (a) may be used individually by 1 type, and may be used together. Similarly, the luminescent material (b) may be used singly or in combination.

Part of the excitation light with a wavelength in the range of 400 nm or more and 500 nm or less is partially transmitted through the color conversion composition according to the embodiment of the present invention, so that the excitation light itself can be used as blue light emission. Therefore, the color conversion composition according to the embodiment of the present invention contains a luminescent material (a) that emits green light and a luminescent material (b) that emits red light. When LEDs are used, each of blue, green, and red has a sharp emission spectrum, and white light with good color purity can be obtained. As a result, more vivid colors and a larger color gamut can be efficiently produced, especially in displays. In addition, in lighting applications, compared to the currently mainstream white LED that combines a blue LED and a yellow phosphor, the emission characteristics are particularly improved in the green region and the red region. You can get a light source.

Examples of the luminescent material (a) include coumarin derivatives such as coumarin 6, coumarin 7 and coumarin 153, cyanine derivatives such as indocyanine green, fluorescein derivatives such as fluorescein, fluorescein isothiocyanate and carboxyfluorescein diacetate, and phthalocyanine derivatives such as phthalocyanine green. , diisobutyl-4,10-dicyanoperylene-3,9-dicarboxylate and other perylene derivatives, pyrromethene derivatives, stilbene derivatives, oxazine derivatives, naphthalimide derivatives, pyrazine derivatives, benzimidazole derivatives, benzoxazole derivatives, benzothiazole Derivatives, imidazopyridine derivatives, azole derivatives, compounds having a condensed aryl ring such as anthracene and their derivatives, aromatic amine derivatives, organometallic complex compounds, and the like are suitable examples. However, the luminescent material (a) is not particularly limited to these. Among these compounds, pyrromethene derivatives are particularly suitable compounds because they provide a high emission quantum yield and good durability. As the pyrromethene derivative, for example, the compound represented by the general formula (1) described above is preferable because it exhibits light emission with high color purity.

Examples of the luminescent material (b) include cyanine derivatives such as 4-dicyanomethylene-2-methyl-6-(p-dimethylaminostyryl)-4H-pyran, and rhodamines such as rhodamine B, rhodamine 6G, rhodamine 101 and sulforhodamine 101. derivatives, pyridine derivatives such as 1-ethyl-2-(4-(p-dimethylaminophenyl)-1,3-butadienyl)-pyridinium-perchlorate, N,N'-bis(2,6-diisopropylphenyl)- Perylene derivatives such as 1,6,7,12-tetraphenoxyperylene-3,4:9,10-bisdicarboimide, porphyrin derivatives, pyrromethene derivatives, oxazine derivatives, pyrazine derivatives, naphthacene and dibenzodiindenoperylene Compounds having a condensed aryl ring such as, derivatives thereof, organometallic complex compounds, and the like are suitable. However, the luminescent material (b) is not particularly limited to these. Among these compounds, pyrromethene derivatives are particularly suitable compounds because they provide a high emission quantum yield and good durability. As the pyrromethene derivative, for example, the compound represented by the general formula (1) described above is preferable because it exhibits light emission with high color purity.

The content of component (A) in the color conversion composition according to the embodiment of the present invention depends on the molar absorption coefficient, emission quantum yield and absorption intensity at the excitation wavelength of the compound, and the thickness and transmittance of the color conversion sheet to be produced. Depending on the factors, it is usually 1.0×10 ⁻⁴ to 30 parts by weight per 100 parts by weight of component (B). Among them, the content of component (A) is more preferably 1.0×10 ⁻³ to 10 parts by weight, more preferably 5.0×10 ^{− 3} to 5 parts by weight is particularly preferred.

When the color conversion composition contains both the luminescent material (a) that emits green light and the luminescent material (b) that emits red light, part of the green light is converted to red light. Therefore, it is preferable that the content w _a of the light-emitting material (a) and the content w _b of the light-emitting material (b) have a relationship of w _a ≧w _b . Also, the ratio between the content w _a and the content w _b is preferably w _a :w _b =1000:1 to 1:1, more preferably 500:1 to 2:1. , 200:1 to 3:1 is particularly preferred. However, the content _wa and the content _wb are percentages by weight relative to the weight of the component (B).

<(B) component: binder resin>
A color conversion composition according to an embodiment of the present invention contains a binder resin as component (B). This binder resin is a binder resin having n kinds of repeating units P ₁ , . . . , P _n (n is a natural number), as described above. As the binder resin, a material excellent in moldability, transparency, heat resistance, etc. is preferably used. For example, specific examples of this binder resin include photocurable resist materials having reactive vinyl groups such as acrylic acid, methacrylic acid, polyvinyl cinnamate, ring rubber, epoxy resins, silicone resins (silicone rubber , silicone gel and other organopolysiloxane cured products (crosslinked products)), urea resins, fluororesins, polycarbonate resins, acrylic resins, urethane resins, melamine resins, polyvinyl resins, polyamide resins, phenol resins, polyvinyl alcohol resins, polyvinyl Known resins such as butyral resins, cellulose resins, aliphatic ester resins, aromatic ester resins, aliphatic polyolefin resins, and aromatic polyolefin resins can be used. A mixture or copolymer of these resins may be used as the binder resin. By appropriately designing these resins, a binder resin useful for the color conversion composition according to the embodiment of the present invention can be obtained.

Among these resins, epoxy resins, silicone resins, acrylic resins, polyester resins, or copolymers or mixtures thereof can be preferably used from the viewpoint of transparency, heat resistance, and the like. In addition, since it exhibits high transparency and excellent dispersibility of the organic light emitting material, the binder resin as the component (B) is an acrylic resin, a copolymer resin containing an acrylic acid ester or methacrylic acid ester moiety, or a polyester resin. Either is preferred. Among these resins, acrylic resins and polyester resins composed only of acrylic acid ester or methacrylic acid ester moieties are preferable in terms of excellent dispersibility of the organic light-emitting material, concentration quenching being suppressed, and sufficient brightness being obtained.

In the present invention, the binder resin as the component (B) may be a thermoplastic resin, a thermosetting resin, or a curable resin such as a photocurable resin. , preferably a thermoplastic resin. When the binder resin is a curable resin such as a thermosetting resin or a photocurable resin, the binder resin may undergo a partial structural change before and after curing. In that case, even after the binder resin is cured, the component (B) preferably satisfies the relationships of the above-mentioned (formula-1) and (formula-2) with the component (A).

Further _, in the present invention, the repeating unit P _i (i is a natural number of 1 or more and n or less) is selected from n types of repeating units P ₁ , . represents a repeating unit (an arbitrary repeating unit) selected for The structure of the repeating unit P _i is not particularly limited, and includes structures of repeating units contained in the resins exemplified above. Although it varies depending on the combination with the component (A), the structure of the repeating unit P _i that satisfies (Formula-1) is preferably an aromatic ring structure having 18 or more ring-constituting carbon atoms or a A structure not containing an aromatic heterocyclic structure having 18 or more is exemplified. More preferred is a structure that does not contain an aromatic ring structure with 16 or more ring-constituting carbon atoms or an aromatic heterocyclic structure with 16 or more ring-constituting carbon atoms. Particularly preferred are structures that do not contain an aromatic ring structure with 14 or more ring-constituting carbon atoms or an aromatic heterocyclic structure with 14 or more ring-constituting carbon atoms.

Moreover, the glass transition temperature (Tg) of the binder resin as the component (B) is not particularly limited, but is preferably 30° C. or higher and 180° C. or lower. When Tg is 30° C. or higher, molecular motion of the binder resin that may occur due to heat due to incident light from a light source or drive heat of equipment is suppressed. This suppresses a change in the state of dispersion of the organic light-emitting material (component (A)) in the binder resin, thereby preventing the durability of the color conversion composition from deteriorating. Further, when the Tg is 180° C. or less, flexibility can be ensured when the color conversion composition is molded into a color conversion sheet or the like. The Tg of the binder resin is more preferably 50° C. or higher and 160° C. or lower, still more preferably 70° C. or higher and 150° C. or lower, and particularly preferably 90° C. or higher and 140° C. or lower.

The molecular weight of the binder resin, which is the component (B), varies depending on the type of resin, and is not particularly limited, but is preferably 3,000 or more and 1,500,000 or less. If this molecular weight is less than 3,000, the binder resin becomes brittle, and as a result, the flexibility of the color conversion composition formed into a color conversion sheet or the like is reduced. If the molecular weight is more than 1,500,000, the viscosity of the binder resin becomes excessively high during molding of the color conversion composition, and the chemical stability of the binder resin itself deteriorates. The molecular weight of the binder resin as component (B) is more preferably from 5,000 to 1,200,000, still more preferably from 7,000 to 1,000,000, and most preferably from 10,000 to 800,000.

<(C) component: other organic components>
The color conversion composition according to the embodiment of the present invention can contain component (C) as another organic component in addition to components (A) and (B) described above. The component (C) is, as described above, q kinds of organic compounds Q ₁ , . . . , Q _q (where q is a natural number). Examples of component (C) include antioxidants, processing and heat stabilizers, light resistance stabilizers such as ultraviolet absorbers, dispersants and leveling agents for stabilizing coating films, plasticizers, epoxy compounds, and the like. curing agents such as amines, acid anhydrides and imidazoles; sheet surface modifiers such as adhesion aids such as silane coupling agents; and other additives. However, when the color conversion composition contains these additives, the HOMO and LUMO energy levels of the organic light-emitting material as component (A) and the HOMO and LUMO energy levels of the additive as component (C) It is preferable that the relationship of the above-mentioned (Formula-7) is satisfied between.

Examples of antioxidants include, but are not limited to, phenolic antioxidants. In addition, antioxidants may be used alone or in combination.

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

Examples of light-resistant stabilizers include benzotriazoles, but are not particularly limited thereto. Also, the light resistance stabilizer may be used alone or in combination.

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

A compound having a role as a singlet oxygen quencher can also be preferably used as the light resistance stabilizer. A singlet oxygen quencher is a material that traps and inactivates singlet oxygen that is generated by activating oxygen molecules with light energy. Coexistence of the singlet oxygen quencher in the color conversion composition or the color conversion sheet can prevent deterioration of the light-emitting material due to singlet oxygen.

Compounds that act as singlet oxygen quenchers include, but are not limited to, certain tertiary amines and metal salts. These compounds (light resistance stabilizers) may be used alone or in combination.

A compound having a role as a radical quencher can also be preferably used as the light resistance stabilizer. Among them, hindered amine-based compounds are suitable examples.

In the color conversion composition and color conversion sheet according to the embodiment of the present invention, the content of these additives is determined by the molar absorption coefficient, emission quantum yield and absorption intensity at the excitation wavelength of the compound, and the color conversion sheet to be produced. Although it depends on the thickness and transmittance of the binder resin, it is preferably 1.0 × 10 ^-2 parts by weight or more, preferably 1.0 × 10 ^-1 parts by weight or more, with respect to 100 parts by weight of the binder resin. More preferably, it is 5.0×10 ⁻¹ parts by weight or more. In addition, 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 binder resin. More preferred.

<Solvent>
The color conversion composition according to the embodiment of the invention may contain a solvent. The solvent is not particularly limited as long as it can adjust the viscosity of the resin in a fluid state and does not excessively affect the light emission and durability of the light-emitting substance. Solvents can be removed from the color conversion composition by drying. Examples of such solvents 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, 1,2-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 is particularly preferred from the viewpoint of not affecting the deterioration of the compound represented by general formula (1). In addition, methyl ethyl ketone, methyl acetate, ethyl acetate, and tetrahydrofuran are preferably used from the viewpoint of less residual solvent after drying.

<Method for producing color conversion composition>
An example of a method for producing a color conversion composition according to an embodiment of the present invention will be described below. In this manufacturing method, predetermined amounts of materials such as the aforementioned organic light-emitting material (component (A)), binder resin (component (B)), and solvent are mixed. After mixing these materials to a predetermined composition, they are uniformly mixed and dispersed using a stirring/kneading machine such as a homogenizer, a revolving stirrer, three rollers, a ball mill, a planetary ball mill, and a bead mill to form a color conversion layer. A make-up composition, ie, a color conversion composition, is made. After mixing and dispersing or during the process of mixing and dispersing, defoaming under vacuum or reduced pressure conditions is also preferably carried out. In addition, it may be possible to mix certain specific components in advance or to perform processing such as aging. It is also possible to remove the solvent by an evaporator to achieve the desired solids concentration.

<Method for preparing color conversion sheet>
The configuration of the color conversion sheet according to the embodiment of the present invention is not limited as long as it includes a color conversion layer composed of a cured layer of a color conversion composition. As representative structural examples of the color conversion sheet, for example, the following first to third examples are given.

FIG. 1 is a schematic cross-sectional view showing a first example of a color conversion sheet according to an embodiment of the invention. As shown in FIG. 1, the color conversion sheet 1A of the first example is a laminate of a base material layer 10 and a color conversion layer 11. As shown in FIG. This color conversion layer 11 is a cured layer of the color conversion composition described above, and is obtained by curing the color conversion composition. In this structural example of the color conversion sheet 1A, the color conversion layer 11 is laminated on the base material layer 10 .

FIG. 2 is a schematic cross-sectional view showing a second example of the color conversion sheet according to the embodiment of the invention. As shown in FIG. 2, the color conversion sheet 1B of the second example is a laminate of a plurality of base layers 10 and a color conversion layer 11. As shown in FIG. In this structural example of the color conversion sheet 1B, a color conversion layer 11 is sandwiched between a plurality of base layers 10. As shown in FIG.

FIG. 3 is a schematic cross-sectional view showing a third example of the color conversion sheet according to the embodiment of the invention. As shown in FIG. 3 , the color conversion sheet 1</b>C of the third example is a laminate of multiple base layers 10 , color conversion layers 11 and multiple barrier layers 12 . In this structural example of the color conversion sheet 1C, a color conversion layer 11 is sandwiched between a plurality of barrier layers 12, and a laminate of these color conversion layers 11 and a plurality of barrier layers 12 is composed of a plurality of base layers 10. sandwiched by That is, the color conversion sheet 1C may be provided with a barrier layer 12 as shown in FIG. 3 in order to prevent deterioration of the color conversion layer 11 due to oxygen, moisture and heat.

Moreover, the color conversion sheet according to the embodiment of the present invention can include two or more color conversion layers. In this color conversion sheet, at least one of the two or more color conversion layers is a color conversion layer comprising a cured layer of the color conversion composition according to the embodiment of the present invention. Typical structural examples of this color conversion sheet include the following fourth to sixth examples.

FIG. 4 is a schematic cross-sectional view showing a fourth example of the color conversion sheet according to the embodiment of the invention. As shown in FIG. 4, the color conversion sheet 1D of the fourth example is a laminate of a base material layer 10 and color conversion layers 11A and 11B. In this structural example of the color conversion sheet 1D, a laminate of color conversion layers 11A and 11B is laminated on a base layer 10 in the order of color conversion layers 11A and 11B. That is, the color conversion sheet 1D includes a substrate layer 10, and on the substrate layer 10, a color conversion layer 11A and a color conversion layer 11B having a laminated structure of color conversion layer 11B/color conversion layer 11A are contained.

FIG. 5 is a schematic cross-sectional view showing a fifth example of the color conversion sheet according to the embodiment of the invention. As shown in FIG. 5, the color conversion sheet 1E of the fifth example is a laminate having a structure in which a color conversion layer 11A and a color conversion layer 11B are sandwiched between a plurality of base layers 10. As shown in FIG. In this structural example of the color conversion sheet 1E, a laminate of the color conversion layers 11A and 11B is laminated on the substrate layer 10 in the order of the color conversion layers 11A and 11B. , another base material layer 10 is laminated on the color conversion layer 11B. That is, the color conversion sheet 1E includes a plurality of base layers 10, and the color conversion layer 11A and the color conversion layer 11A having a laminated structure of color conversion layer 11B/color conversion layer 11A are sandwiched between the base layers 10. It contains a color conversion layer 11B.

FIG. 6 is a schematic cross-sectional view showing a sixth example of the color conversion sheet according to the embodiment of the invention. As shown in FIG. 6, in the color conversion sheet 1F of the sixth example, the transparent intermediate layer 13 is sandwiched between the color conversion layers 11A and 11B. It is a laminate having a structure in which a transparent intermediate layer 13 is sandwiched between a plurality of base material layers 10 . In this structural example of the color conversion sheet 1E, a laminate of a color conversion layer 11A, a color conversion layer 11B, and a transparent intermediate layer 13 is formed on a base material layer 10 with a color conversion layer 11A, a transparent intermediate layer 13, and a color conversion layer. 11B, and another base material layer 10 is laminated on the color conversion layer 11B. That is, the color conversion sheet 1E includes a plurality of base layers 10, and is sandwiched between the plurality of base layers 10, and has a laminated structure of color conversion layer 11B/transparent intermediate layer 13/color conversion layer 11A. Color conversion layer 11A, color conversion layer 11B and transparent intermediate layer 13 are included.

In each of the color conversion sheets 1D to 1F illustrated in FIGS. 4 to 6, at least one of the two layers of the color conversion layer 11A and the color conversion layer 11B is formed by curing the color conversion composition according to the embodiment of the present invention. It is a layer that consists of Further, the number of color conversion layers included in the color conversion sheets 1D to 1F is not limited to two layers as described above, and may be three layers or more.

In addition to the structural examples shown in FIGS. 4 to 6, examples of the structure of the color conversion sheet having two or more color conversion layers include color conversion layer 11A/color conversion layer 11A/color conversion layer 11B, A configuration in which the same color conversion layers are continuous, such as color conversion layer 11A/color conversion layer 11B/color conversion layer 11B and color conversion layer 11A/color conversion layer 11A/color conversion layer 11B/color conversion layer 11B, is also possible.

Note that these are examples, and the specific configurations of the color conversion sheets according to the embodiments of the present invention are not limited to these, and configurations appropriately modified according to matters derived from the following description are also included in the present invention. Included in the scope.

(color conversion layer)
Next, an example of a method for manufacturing the color conversion layer of the color conversion sheet according to the embodiment of the invention will be described. In this method for producing a color conversion layer, the color conversion composition prepared by the method described above is applied onto a substrate such as a substrate layer or a barrier layer, and then dried. Reverse roll coater, blade coater, slit die coater, direct gravure coater, offset gravure coater, kiss coater, natural roll coater, air knife coater, roll blade coater, reverse roll blade coater, two stream coater, rod coater, wire bar A coater, applicator, dip coater, curtain coater, spin coater, knife coater, or the like can be used. In order to obtain uniform film thickness of the color conversion layer, it is preferable to apply with a slit die coater.

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

After producing the color conversion layer, it is also possible to change the base layer if necessary. In this case, examples of simple methods include, but are not limited to, a method using a hot plate for re-sticking, a method using a vacuum laminator or a dry film laminator, and the like.

When the color conversion sheet according to the embodiment of the present invention includes two or more color conversion layers, a known method such as coating or dry lamination is used for laminating each layer of the two or more color conversion layers. be able to. In the present invention, the lamination method of each layer is not particularly limited. Specifically, a method of forming a second color conversion layer on a first color conversion layer by coating and drying, and a method of forming a first color conversion layer on a second color conversion layer by coating and drying. method, a method in which a separately molded free-standing film for the second color conversion layer is laminated on the first color conversion layer, and a method in which a separately molded free-standing film for the first color conversion layer is laminated on the second color conversion layer. laminating a laminated unit with a laminated structure of "base material layer/first color conversion layer" and a laminated unit with a laminated structure of "second color conversion layer/base layer", etc. , and a method of laminating individually produced lamination units. In order to enhance the stability of the color conversion sheet, it is also preferable to further perform a heat curing process, a photocuring process, an aging process, etc. after laminating each layer.

Although the thickness of the color conversion layer is not particularly limited, it is preferably 1 μm or more and 1000 μm or less, more preferably 10 μm or more and 1000 μm or less. If the thickness of the color conversion layer is less than 1 μm, there is a problem that the toughness of the color conversion sheet is reduced. If the thickness of the color conversion layer exceeds 1000 μm, cracks are likely to occur, making it difficult to mold the color conversion sheet. The thickness of the color conversion layer is more preferably 5 μm or more and 100 μm or less, still more preferably 10 μm or more and 100 μm or less, and particularly preferably 15 μm or more and 100 μm or less.

The film thickness (layer thickness) of the color conversion sheet in the present invention is a film measured based on Method A for measuring thickness by mechanical scanning in JIS K7130 (1999) Plastics-Films and Sheets-Methods for measuring thickness. Thickness (average film thickness).

(Base material layer)
As the base material layer (for example, the base material layer 10 shown in FIGS. 1 to 6, etc.), known metals, films, glass, ceramics, paper, and the like can be used without particular limitation. Specifically, as the base material layer, aluminum (including aluminum alloy), zinc, copper, metal plate or foil such as iron, cellulose acetate, polyethylene terephthalate (PET), polyethylene, polyester, polyamide, polyimide, polyphenylene sulfide, Plastic films such as polystyrene, polypropylene, polycarbonate, polyvinyl acetal, aramid, silicone, polyolefin, thermoplastic fluororesin, copolymer of tetrafluoroethylene and ethylene (ETFE), α-polyolefin resin, polycaprolactone resin, acrylic resin , a plastic film made of a silicone resin and a copolymer resin of these and ethylene, paper laminated with the plastic, paper coated with the plastic, paper laminated or vapor-deposited with the metal, laminated or vapor-deposited with the metal A vapor-deposited plastic film and the like can be mentioned. Moreover, when the base material layer is a metal plate, the surface thereof may be subjected to plating treatment such as chromium-based or nickel-based plating or ceramic treatment.

Among these, glass and resin film are preferably used because of the ease of production of the color conversion sheet and the ease of molding the color conversion sheet. Moreover, a film having high strength is preferable so that there is no risk of breakage or the like when the film-like base layer is handled. Resin films are preferred from the viewpoints of the required properties and economy, and among these, plastic films selected from the group consisting of PET, polyphenylene sulfide, polycarbonate and polypropylene are preferred from the viewpoints of economy and handleability. Further, when the color conversion sheet is dried or when the color conversion sheet is press-molded at a high temperature of 200° C. or higher by an extruder, a polyimide film is preferable in terms of heat resistance. The surface of the base material layer may be subjected to a release treatment in advance so that the sheet can be easily peeled off. Similarly, the surface of the base material layer may be pretreated for easy adhesion in order to improve the adhesion between the layers.

The thickness of the substrate layer is not particularly limited, but the lower limit is preferably 12 μm or more, more preferably 38 μm or more. Moreover, as an upper limit, 5000 micrometers or less are preferable, and 3000 micrometers or less are more preferable.

(barrier layer)
The color conversion sheet according to the embodiment of the present invention may further have a barrier layer (for example, barrier layer 12 shown in FIG. 3) in addition to the color conversion layer. A barrier layer is appropriately used to prevent the color conversion layer from being deteriorated by oxygen, moisture or heat. Examples of the barrier layer include inorganic oxides such as silicon oxide, aluminum oxide, titanium oxide, tantalum oxide, zinc oxide, tin oxide, indium oxide, yttrium oxide, magnesium oxide, silicon nitride, aluminum nitride, titanium nitride, Inorganic nitrides such as silicon carbide nitride, mixtures thereof, metal oxide thin films and metal nitride thin films added with other elements, polyvinyl chloride resins, acrylic resins, silicon resins, melamine resins Films made of various resins such as resins, urethane-based resins, fluorine-based resins, and polyvinyl alcohol-based resins such as saponified vinyl acetate can be used.

Examples of barrier resins suitable for use in the barrier layer of the present invention include resins such as polyester, polyvinyl chloride, nylon, polyvinyl fluoride, polyvinylidene chloride, polyacrylonitrile, polyvinyl alcohol, and ethylene-vinyl alcohol copolymer. and mixtures of these resins. Among them, polyvinylidene chloride, polyacrylonitrile, ethylene-vinyl alcohol copolymer, and polyvinyl alcohol have very small oxygen permeability coefficients, so the barrier resin preferably contains these resins. Furthermore, the barrier resin more preferably contains polyvinylidene chloride, polyvinyl alcohol, or ethylene-vinyl alcohol copolymer because of its resistance to discoloration. It is particularly preferred to include coalescing. These resins may be used singly or in combination with different resins, but from the viewpoint of layer uniformity and cost, a barrier layer made of a single resin is more preferable.

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

Moreover, as a barrier layer, it is also possible to use commercially available resins and films. Specific examples include polyvinyl alcohol resin PVA117 manufactured by Kuraray Co., Ltd., ethylene-vinyl alcohol copolymer (“EVAL” (registered trademark)) resins L171B and F171B manufactured by Kuraray Co., Ltd., and film EF-XL.

The barrier layer may contain antioxidants, curing agents, cross-linking agents, processing and heat stabilizers, ultraviolet absorbers, etc., as necessary, within a range that does not excessively affect the light emission and durability of the color conversion layer. Light resistance stabilizers and the like may be added.

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

In the present invention, the barrier layer may be provided on each end face on both sides of the color conversion layer 11 in the stacking direction like the barrier layer 12 illustrated in FIG. may be provided on one end surface of the In addition, when the color conversion sheet includes two or more color conversion layers, typical structural examples of the color conversion sheet to which the above-described barrier layer is applied include, for example, the following.

FIG. 7 is a schematic cross-sectional view showing a seventh example of the color conversion sheet according to the embodiment of the invention. As shown in FIG. 7, the color conversion sheet 1G of the seventh example includes a plurality of base material layers 10, and a color conversion layer 11A and a color conversion layer 11A and a color conversion layer 11A sandwiched between the base layers 10. It contains a layer 11B and a plurality of (two layers in the example of FIG. 7) barrier layers 12 . These plurality of barrier layers 12 are formed so as to sandwich the layered body of the color conversion layer 11A and the color conversion layer 11B from both sides in the layering direction. In this structural example of the color conversion sheet 1G, a barrier layer 12, a color conversion layer 11A, a color conversion layer 11B, and another barrier layer 12 are laminated in this order on a base layer 10. . As a result, a laminate having a laminated structure of barrier layer 12/color conversion layer 11B/color conversion layer 11A/barrier layer 12 is formed on the base layer 10. FIG. Furthermore, as shown in FIG. 7, another base material layer 10 is laminated on the barrier layer 12 on the upper side in the lamination direction of this laminate.

FIG. 8 is a schematic cross-sectional view showing an eighth example of the color conversion sheet according to the embodiment of the invention. As shown in FIG. 8, a color conversion sheet 1H of the eighth example includes a plurality of base material layers 10, and a color conversion layer 11A and a color conversion layer 11A and a color conversion sheet 1H are sandwiched between the plurality of base material layers 10 as shown in FIG. It contains a layer 11B and a plurality of (three layers in the example of FIG. 8) barrier layers 12 . The plurality of barrier layers 12 are formed so as to sandwich the color conversion layer 11A from both sides in the stacking direction and sandwich the color conversion layer 11B from both sides in the stacking direction. In this structural example of the color conversion sheet 1H, a barrier layer 12, a color conversion layer 11A, another barrier layer 12, a color conversion layer 11B, and another barrier layer 12 are formed on the base layer 10. are laminated in this order. As a result, a laminate having a laminate structure of barrier layer 12/color conversion layer 11B/barrier layer 12/color conversion layer 11A/barrier layer 12 is formed on the base layer 10. FIG. Furthermore, as shown in FIG. 8, another base material layer 10 is laminated on the barrier layer 12 at the upper end in the lamination direction of this laminate.

In the color conversion sheet including two or more color conversion layers, the barrier layers are provided on both sides in the stacking direction of the laminate of the color conversion layers 11A and 11B, like the barrier layer 12 illustrated in FIG. Alternatively, although not shown, it may be provided only on one end face (one side) of both sides in the lamination direction of this laminate. Also, the barrier layer may be provided on both sides of the color conversion layer 11A in the lamination direction and on both sides of the color conversion layer 11B in the lamination direction, like the barrier layer 12 illustrated in FIG.

(Other functional layers)
The color conversion sheet according to the embodiment of the present invention has a light diffusion function, an antireflection function, an antiglare function, an antireflection antiglare function, a hard coat function (anti-friction function), an electrification An auxiliary layer having an antifouling function, an antifouling function, an electromagnetic wave shielding function, an infrared ray cutting function, an ultraviolet ray cutting function, a polarizing function, and a toning function may be further provided.

(adhesive layer)
In the color conversion sheet according to the embodiment of the present invention, an adhesive layer may be provided between each layer, if necessary. As the adhesive layer, known materials can be used without particular limitation as long as they do not excessively affect the light emission and durability of the color conversion sheet. For example, when strong adhesion is required, a photocurable material, a thermosetting material, an anaerobic curable material, or a thermoplastic material can be preferably used as the adhesive layer. Among them, thermosetting materials are more preferable, and thermosetting materials that can be cured at 0° C. to 150° C. are particularly preferable.

Although the thickness of the adhesive layer is not particularly limited, it is preferably 0.01 μm or more and 100 μm or less, more preferably 0.01 μm or more and 25 μm or less. It is more preferably 0.05 μm or more and 5 μm or less, and particularly preferably 0.05 μm or more and 1 μm or less.

<Excitation light>
Any type of excitation light can be used as long as it emits light in a wavelength region that can be absorbed by the organic light-emitting material used in the present invention. For example, excitation light from any light source such as a hot-cathode tube, a cold-cathode tube, a fluorescent light source such as an inorganic electroluminescence (EL) element, an organic EL element light source, an LED light source, an incandescent light source, or sunlight can be used. be. Among them, light from an LED light source is suitable excitation light. For display and lighting applications, light from a blue LED light source emitting light in a wavelength range of 400 nm or more and 500 nm or less is more suitable excitation light in terms of increasing the color purity of blue light.

The maximum emission wavelength of the excitation light is more preferably 430 nm or more and 500 nm or less, since the excitation energy becomes smaller and the deterioration of the organic light emitting material can be suppressed, and it is more preferably 440 nm or more and 500 nm or less. Especially preferably, it is 450 nm or more and 500 nm or less. In addition, the maximum emission wavelength of the excitation light is more preferably 480 nm or less, more preferably 470 nm or less, because it is possible to reduce the overlap of the emission spectra of the excitation light and the green light and improve the color reproducibility. is more preferred.

The excitation light may have one type of emission peak, or may have two or more types of emission peaks, but preferably has one type of emission peak in order to increase color purity. It is also possible to arbitrarily combine a plurality of excitation light sources with different types of emission peaks.

<Light source unit>
A light source unit according to an embodiment of the present invention includes at least the light source described above and the color conversion composition or color conversion sheet described above. When the light source unit includes the color conversion composition, the arrangement method of the light source and the color conversion composition is not particularly limited. A configuration in which the color conversion composition is applied to a separated film, glass, or the like may be adopted. When the light source unit includes a color conversion sheet, the arrangement method of the light source and the color conversion sheet is not particularly limited. It can also take remote phosphor form. In addition, the light source unit may further include a color filter for the purpose of increasing color purity.

As described above, the excitation light with a wavelength of 400 nm or more and 500 nm or less has relatively small excitation energy, and can prevent the decomposition of the light-emitting substance such as the compound represented by the general formula (1). Therefore, the light source provided in the light source unit is preferably a light-emitting diode that emits maximum light in the wavelength range of 400 nm or more and 500 nm or less. Furthermore, this light source preferably has a maximum emission in the wavelength range of 430 nm to 480 nm, and more preferably has a maximum emission in the wavelength range of 450 nm to 470 nm. The light source unit of the present invention can be used for displays, lighting, interiors, signs, signboards, etc., and is particularly suitable for displays and lighting.

<Display, lighting device>
A display according to an embodiment of the present invention includes at least a light source unit including a light source, a color conversion sheet, and the like, as described above. For example, the light source unit described above is used as a backlight unit in a display such as a liquid crystal display. Moreover, the illumination device according to the embodiment of the present invention includes at least a light source unit including a light source, a color conversion sheet, and the like, as described above. For example, this illumination device combines a blue LED light source as a light source unit and a color conversion sheet or color conversion composition that converts the blue light from the blue LED light source into light with a longer wavelength to produce white light. is configured to emit a

EXAMPLES The present invention will be described below with reference to examples, but the present invention is not limited by the following examples. In the following examples and comparative examples, compounds D-1 to D-6 and compounds Q-1 to Q-4 are compounds shown below. Resins P-1 to P-4 are resins shown below.

Evaluation methods for structural analysis, color conversion characteristics, light durability, and energy calculation in Examples and Comparative Examples are as follows.

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

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

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

<Measurement of color conversion characteristics>
In the measurement of the color conversion characteristics, each color conversion sheet and prism sheet were placed on a planar light emitting device equipped with a blue LED element (manufactured by USHIO EPITEX; model number SMBB450H-1100, emission peak wavelength: 450 nm). A current of 30 mA was applied to the light-emitting device to light the blue LED element, and the emission spectrum and emission intensity at the peak wavelength were measured using a spectral radiance meter (CS-1000, manufactured by Konica Minolta).

<Light durability test>
In the light durability test, each color conversion sheet and prism sheet were placed on a planar light emitting device equipped with a blue LED element (manufactured by USHIO EPITEX; model number SMBB450H-1100, emission peak wavelength: 450 nm). A current of 100 mA was passed through the light-emitting device to light the blue LED element, and the emission intensity at the peak wavelength of the color-converted emission was measured using a spectral radiance meter (CS-1000, manufactured by Konica Minolta). . After that, light from a blue LED element was continuously irradiated in an environment of 50° C. and 27% RH, and the light durability was evaluated by observing the time until the peak intensity decreased by a certain amount. However, the emission intensity was measured after the color conversion sheet and the planar light emitting device were taken out of the oven and cooled to room temperature.

<Energy calculation>
In this example, the energy levels of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) of the repeating unit of the organic light-emitting material and the binder resin were calculated by the following calculation method. BIOVIA Materials Studio 2016 manufactured by BIOVIA was used as molecular orbital calculation software, and molecular orbital calculation based on the density functional (DFT) method was performed. Geometry optimization and energy calculations of the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) were performed using the DFT method program package Dmol3. At that time, BLYP of GGA was used as the density functional, and DND (double-numeric quality basis set + d-polarization functions for heavy atoms) was used as the basis function. The Energy of Highest Occupied Molecular Orbital value output to the outmol file, which is the calculation result, was used as the HOMO energy level, and the Energy of Lowest Unoccupied Molecular Orbital value was used as the LUMO energy level.

As an example, Table 1 shows the calculation results of the repeating units of resins P-1 to P-4 used in the following examples and comparative examples.

(Synthesis example 1)
A method for synthesizing compound D-3 of Synthesis Example 1 will be described. In the method for synthesizing compound D-3, 3,5-dibromobenzaldehyde (3.0 g), 4-(methoxycarbonyl)phenylboronic acid (5.4 g), tetrakis(triphenylphosphine) palladium (0) (0.4 g ) and potassium carbonate (2.0 g) were placed in a flask and the flask was purged with nitrogen. To this was added degassed toluene (30 mL) and degassed water (10 mL) and refluxed for 4 hours. The resulting reaction solution was cooled to room temperature, and the organic layer was separated and washed with saturated brine. The organic layer was dried over magnesium sulfate, filtered, and the solvent was distilled off. The resulting reaction product was purified by silica gel chromatography to give 3,5-bis[4-(methoxycarbonyl)phenyl]benzaldehyde (3.5 g) as a white solid.

Next, 3,5-bis[4-(methoxycarbonyl)phenyl]benzaldehyde (1.5 g) and 2,4-dimethylpyrrole (0.7 g) were added to the reaction solution, dehydrated dichloromethane (200 mL) and trifluoro Acetic acid (1 drop) was added and stirred for 4 hours under a nitrogen atmosphere. Subsequently, a dehydrated dichloromethane solution of 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (0.85 g) was added, and the mixture was further stirred for 1 hour. After completion of the reaction, boron trifluoride diethyl ether complex (7.0 mL) and diisopropylethylamine (7.0 mL) were added, and after stirring for 4 hours, water (100 mL) was further added and stirred, and the organic layer was separated. bottom. The organic layer was dried over magnesium sulfate, filtered, and the solvent was distilled off. The obtained reaction product was purified by silica gel chromatography to obtain a compound (0.4 g) (yield 18%). The results of ¹ H-NMR analysis of the obtained compound are as follows, confirming that it is compound D-3.
¹ H-NMR (CDCl ₃ , ppm): 8.01 (s, 1H), 7.63-7.48 (m, 10H), 6.00 (s, 2H), 3.96 (s, 6H)

The absorption spectrum of this compound D-3 was as shown in FIG. 9, and exhibited light absorption characteristics for a blue excitation light source (460 nm). The fluorescence spectrum of this compound D-3 was as shown in FIG. 10, showing a sharp emission peak in the green region. The emission quantum yield was 83%, and this compound D-3 was a compound capable of efficient color conversion.

(Synthesis example 2)
A method for synthesizing compound D-5 of Synthesis Example 2 will be described. In the synthesis method of compound D-5, 4-(4-t-butylphenyl)-2-(4-methoxyphenyl)pyrrole (300 mg), 2-methoxybenzoyl chloride (201 mg), and toluene (10 mL) The mixed solution was heated at 120° C. for 6 hours under a nitrogen stream. The heated solution was cooled to room temperature and then evaporated. Subsequently, after washing with ethanol (20 mL) and vacuum drying, 2-(2-methoxybenzoyl)-3-(4-t-butylphenyl)-5-(4-methoxyphenyl)pyrrole (260 mg) was obtained. rice field.

Next, 2-(2-methoxybenzoyl)-3-(4-t-butylphenyl)-5-(4-methoxyphenyl)pyrrole (260 mg) and 4-(4-t-butylphenyl)-2- A mixed solution of (4-methoxyphenyl)pyrrole (180 mg), methanesulfonic anhydride (206 mg) and degassed toluene (10 mL) was heated at 125° C. for 7 hours under a stream of nitrogen. After cooling the heated solution to room temperature, water (20 mL) was injected and the organic layer was extracted with dichloromethane (30 mL). The organic layer was washed twice with water (20 mL), evaporated and dried in vacuo to give pyrromethene.

Next, diisopropylethylamine (305 mg) and boron trifluoride diethyl ether complex (670 mg) were added to a mixed solution of the obtained pyrromethene compound and toluene (10 mL) under a nitrogen stream, and the mixture was stirred at room temperature for 3 hours. After that, water (20 mL) was injected and the organic layer was extracted with dichloromethane (30 mL). The organic layer was washed twice with water (20 mL), dried over magnesium sulfate, and evaporated. Subsequently, the product was purified by silica gel column chromatography and vacuum-dried to obtain a reddish purple powder (0.27 g). The results of ¹ H-NMR analysis of the reddish-purple powder obtained are as follows, and it was confirmed that the reddish-purple powder obtained as described above was Compound D-5.
¹ H-NMR (CDCl ₃ , ppm): 1.19 (s, 18H), 3.42 (s, 3H), 3.85 (s, 6H), 5.72 (d, 1H), 6.20 (t, 1H), 6.42-6.97 (m, 16H), 7.89 (d, 4H)

The absorption spectrum of this compound D-5 was as shown in FIG. 11, showing light absorption characteristics for blue and green excitation light sources. The fluorescence spectrum of this compound D-5 was as shown in FIG. 12, showing a sharp emission peak in the red region. The emission quantum yield was 90%, and this compound D-5 was a compound capable of efficient color conversion.

On the other hand, compounds D-1, D-2, and D-6 were synthesized using a known method in the same manner as in the Synthesis Examples above. Compound D-4 used was a 98% pure product manufactured by Sigma-Aldrich.

(Example 1)
In Example 1 of the present invention, an acrylic resin (resin P-1) was used as the (B) component, and 0.3 of the compound D-1 was added as the (A) component to 100 parts by weight of the (B) component. 300 parts by weight of ethyl acetate was mixed as a solvent. These mixtures were stirred and defoamed at 300 rpm for 30 minutes using a planetary stirring and defoaming device "Mazerustar" (registered trademark) KK-400 (manufactured by Kurabo Industries, Ltd.). got stuff

Then, using a slit die coater, the color conversion composition of Example 1 was applied onto the substrate layer “Lumirror” (registered trademark) U34 (manufactured by Toray Industries, Inc., thickness 75 μm) and dried at 120° C. to 60° C. After heating for 1 minute and drying, a color conversion layer having an average thickness of 18 μm was formed. Finally, after lamination with a diffusion film (“Texcell” (registered trademark) TDF127 manufactured by Toray Advanced Materials Co., Ltd.), it was aged at 60° C. for 1 hour to obtain a color conversion sheet of Example 1.

In this Example 1, the HOMO energy level E _A (H) and the LUMO energy level E _A (L) of the (A) component were −5.51 eV and −3.56 eV, respectively. Among the HOMO energy levels of the repeating units of component (B), the highest energy level E _B (H)max was −5.80 eV. Among the LUMO energy levels of the repeating units of component (B), the lowest energy level E _B (L)min was −0.61 eV. That is, E _B (H) max < E _A (H) < E _A (L) < E _B (L) min, and the components (A) and (B) of Example 1 are (Formula-1) satisfied the relationship.

Further, when the blue LED light was color-converted using the color conversion sheet of Example 1, when only the green light emission region was extracted, a high color purity green color with a peak wavelength of 527 nm and a half width of the emission spectrum at the peak wavelength of 33 nm was obtained. Luminescence was obtained. Taking the emission intensity at the peak wavelength of this Example 1 as 1.0, the emission intensity of this Example 1 was compared with those of Examples 2-20 and Comparative Examples 1-3. Further, when light from the blue LED element was continuously irradiated in an environment of 50° C. and 27% RH according to the method described above, it took 250 hours for the emission intensity to decrease by 10%. The results of Example 1 are shown in Table 2 below.

(Examples 2-11 and Comparative Examples 1-3)
In Examples 2 to 11 of the present invention and Comparative Examples 1 to 3 of the present invention, the compounds (Compounds D-1 to D-4) listed in Table 2 were used as the (A) component and Table 2 was used as the (B) component. Color conversion sheets were prepared and evaluated in the same manner as in Example 1 except that the resins (resins P-1 to P-4) described in 1. were used. However, the amount of component (A) mixed was adjusted so as to be the same amount of substance as compound D-1 of Example 1. The results of Examples 2-11 and Comparative Examples 1-3 are shown in Table 2. However, the emission intensity (relative value) in Table 2 is a relative value when the emission intensity in Example 1 is set to 1.00.

(Example 12)
In Example 12 of the present invention, compound Q-1 shown in Table 2 was used as component (C), and 1.0 part by weight of compound Q-1 was added to 100 parts by weight of component (B). A color conversion sheet was prepared and evaluated in the same manner as in Example 1, except that the mixture was mixed in . The results of Example 12 are shown in Table 2. However, the emission intensity (relative value) in Table 2 is a relative value when the emission intensity in Example 1 is set to 1.00.

In this Example 12, the HOMO energy level E _A (H) and the LUMO energy level E _A (L) of the (A) component were −5.51 eV and −3.56 eV, respectively. Among the HOMO energy levels of the repeating units of component (B), the highest energy level E _B (H)max was −5.80 eV. Among the LUMO energy levels of the repeating units of component (B), the lowest energy level E _B (L)min was −0.61 eV. The HOMO energy level E _C (H) and the LUMO energy level E _C (L) of the component (C) were −6.24 eV and −2.61 eV, respectively. That is, E _B (H) max < E _A (H) < E _A (L) < E _B (L) min, and the components (A) and (B) of Example 12 are (formula-1) satisfied the relationship. Furthermore, E _C (H) < E _A (H) < E _A (L) < E _C (L), and the components (A) and (C) of Example 12 have the relationship of (Formula-7) met.

(Examples 13-20)
In Examples 13 to 20 of the present invention, the compounds (Compounds D-1 to D-4) listed in Table 2 were used as the component (A), and the resin listed in Table 2 (Resin P-1) was used as the component (B). ) and using the compounds (compounds Q-1 to Q-3) listed in Table 2 as the component (C), a color conversion sheet was produced and evaluated in the same manner as in Example 12. However, the amount of component (A) mixed was adjusted so as to be the same amount of substance as compound D-1 of Example 1. The results of Examples 13-20 are shown in Table 2. However, the emission intensity (relative value) in Table 2 is a relative value when the emission intensity in Example 1 is set to 1.00.

(Example 21)
In Example 21 of the present invention, compound D-5 was used as component (A), and 0.1 part by weight of compound D-5 was mixed with 100 parts by weight of component (B). A color conversion sheet of Example 21 was produced in the same manner as in Example 1.

When blue LED light was color-converted using the color conversion sheet of Example 21, high color purity red light emission with a peak wavelength of 635 nm and a half width of the emission spectrum at the peak wavelength of 49 nm was obtained by extracting only the red light emission region. Got. Taking the emission intensity at the peak wavelength of this Example 21 as 1.0, the emission intensity of this Example 21 was compared with those of Examples 22-25. Further, when light from the blue LED element was continuously irradiated in an environment of 50° C. and 27% RH according to the method described above, it took 250 hours for the emission intensity to decrease by 10%. The results of Example 21 are shown in Table 3 below.

(Examples 22-25)
In Examples 22 to 25 of the present invention, the compounds (Compounds D-5 and D-6) listed in Table 3 were used as the component (A), and the resin listed in Table 3 (Resin P-1) was used as the component (B). , P-2) and appropriately using the compounds (compounds Q-3 and Q-4) listed in Table 3 as the (C) component. evaluated. However, the amount of component (A) mixed was adjusted so as to be the same amount of substance as compound D-5 of Example 21. The results of Examples 22-25 are shown in Table 3. However, the emission intensity (relative value) in Table 3 is a relative value when the emission intensity in Example 21 is set to 1.00.

Among the above-described Examples 1 to 25 and Comparative Examples 1 to 3, when comparing Examples 1 and 2 using the same compound D-1 as the component (A) with Comparative Examples 1 and 2, (Formula-1) In Examples 1 and 2, which satisfy the relationship, both high emission intensity and high light durability were achieved. On the other hand, in Comparative Examples 1 and 2, which did not satisfy the relationship of (Formula-1), the emission intensity was low and the light durability was also low.

Similarly, when comparing Examples 3 to 5 using the same compound D-2 as the component (A) and Comparative Example 3, only Examples 3 to 5 that satisfy the relationship of (Formula-1) show high emission intensity. and high light durability.

On the other hand, when comparing Examples 7, 8 and 10 with Comparative Examples 1 to 3, when the component (A) is compound D-1 or compound D-2 as in Comparative Examples 1 to 3, the emission intensity and light Even when the component (B) (resin P-2 or resin P-4) with reduced durability was used as the component (B) in Examples 7, 8, and 10, Examples 7, 8, In No. 10, when compound D-3 or compound D-4 was used as the component (A), both high emission intensity and high light durability were achieved because the relationship of formula-1 was satisfied.

Compare Examples 12 and 13; Compare Examples 14, 15 and 16; Compare Examples 17 and 18; Compare Examples 19 and 20 As a result, when the relationship of (Equation-7) was satisfied for the components (A) and (C), both high emission intensity and high light durability were achieved. On the other hand, when the relationship of (Formula-7) was not satisfied, the emission intensity and light durability were lower than when the relationship of (Formula-7) was satisfied.

When comparing Examples 1 and 3 using the same resin P-1 as the component (B) with Examples 6 and 9, the energy level E _A (H) of the HOMO of the component (A) is (Formula-4) Higher light durability was obtained in Examples 1 and 3 satisfying the above.

Examples 21 to 23 where the components (A) and (B) satisfy the relationship of (Formula-1) and the HOMO energy level E _A (H) of the component (A) satisfies (Formula-5) Also with regard to, both high emission intensity and high light durability were achieved.

Comparing Example 24 and Example 25, both high emission intensity and high light durability were achieved when the relationship of (Formula-7) was satisfied for the components (A) and (C). On the other hand, when the relationship of (Formula-7) was not satisfied, the emission intensity and light durability were lower than when the relationship was satisfied.

(Comparative Example 4)
In Comparative Example 4 for the present invention, a two-component thermosetting epoxy acrylic resin (resin P-5) was used as component (B), methyl ethyl ketone was used as a solvent, and 100% of resin P-5 as component (B) was used. A color conversion sheet was produced and evaluated in the same manner as in Example 1 except that 300 parts by weight of this methyl ethyl ketone was mixed with the parts by weight. The results of Comparative Example 4 are shown in Table 4. However, the emission intensity (relative value) in Table 4 is a relative value when the emission intensity in Example 1 is set to 1.00.

Comparing Example 1 using a thermoplastic acrylic resin (resin P-1) with Comparative Example 4 using a two-component thermosetting epoxy acrylic resin (resin P-5), (Formula-1) In Example 1 satisfying the relationship, both high emission intensity and high light durability were achieved. On the other hand, in Comparative Example 4, which does not satisfy the relationship of (Formula-1), the luminescence intensity and light durability are lower than those of Example 1, which satisfies the relationship.

As described above, the color conversion composition, the color conversion sheet, the light source unit, the display, and the lighting device according to the present invention can achieve both high durability and high luminous efficiency. Suitable for sheets, light source units, displays and lighting devices.

1A, 1B, 1C, 1D, 1E, 1F, 1G, 1H Color Conversion Sheet 10 Base Layer 11, 11A, 11B Color Conversion Layer 12 Barrier Layer 13 Transparent Intermediate Layer

Claims (21)

A color conversion composition that converts incident light into light of a longer wavelength than the incident light,
(A) component which is m types of organic light-emitting materials D ₁ , . . . , D _m (m is a natural number);
Component (B), which is a binder resin having n types of repeating units P ₁ , . . . , P _n (where n is a natural number);
including
The energy level of the highest occupied molecular orbital for any organic light-emitting material D _h (h is a natural number of 1 or more and m or less) arbitrarily selected from the m kinds of organic light-emitting materials D ₁ , . . . , D _m is E _Ah (H) [eV], the energy level of the lowest unoccupied molecular orbital is E _Ah (L) [eV], and arbitrarily selected from the n types of repeating units P ₁ , ..., P _n For any repeating unit P _i (i is a natural number from 1 to n) , the energy level of the highest occupied molecular orbital is E _Bi (H) [eV], and the energy level of the lowest unoccupied molecular orbital is E _Bi (L ₎ [ eV ] , E _Ah (H ₎ , E _Ah (L), E _Bi (H), and E _Bi (L) satisfy (Formula-1),
A color conversion composition characterized by:
E _Bi (H) ≤ E _Ah (H) ≤ E _Ah (L) ≤ E _Bi (L) (Formula-1) E _Ah ( _H ) and E _Bi (H) are given by _the formula -2) is satisfied,
The color conversion composition according to claim 1, characterized by:
E _Bi (H) ≤ E _Ah (H) - 0.05 (Formula-2) _{E Ah (} L ₎ and E _Bi (L) are given by the formula - satisfies 3),
3. The color conversion composition according to claim 1 or 2, characterized by:
E _Ah (L) + 0.05 ≤ E _Bi (L) (Formula-3) E _Ah (H) satisfies either (Formula-4) or (Formula-5) for the optional organic light-emitting material D _h in the component (A);
4. The color conversion composition according to any one of claims 1 to 3, characterized by:
E _Ah (H)≤-5.00 (Formula-4)
E _Ah (H)≧−4.50 (Formula-5) At least one of the m types of organic light-emitting materials satisfies (Formula-6),
The color conversion composition according to any one of claims 1 to 4, characterized by:
E _Ah (H) ≤ -5.00 (Formula-6) The component (B) is an acrylic resin, a copolymer resin containing an acrylic acid ester or methacrylic acid ester moiety, or a polyester resin.
6. The color conversion composition according to any one of claims 1 to 5, characterized by: wherein the component (B) is a thermoplastic resin,
The color conversion composition according to any one of claims 1 to 6, characterized by: In addition to the (A) component and the (B) component, the (C) component is q kinds of organic compounds Q ₁ , . . . , Q _q (where q is a natural number),
The energy level of the highest occupied molecular orbital of an arbitrary organic compound Q _j (j is a natural number equal to or greater than 1 and equal to or less than q) _arbitrarily selected from the q kinds of organic compounds Q ₁ , . When _Cj (H) [eV] and the energy level of the lowest unoccupied molecular orbital is E _Cj (L) [eV], the arbitrary organic light-emitting material D _h in the component (A) and the component (C) E _Ah (H), E _Ah (L), E _Cj (H), and E _Cj (L) satisfy (Formula-7) for all possible combinations with the arbitrary organic compound Q _j ;
The color conversion composition according to any one of claims 1 to 7, characterized by:
E _Cj (H) ≤ E _Ah (H) ≤ E _Ah (L) ≤ E _Cj (L) (Formula-7) wherein the component (A) contains at least a compound represented by the general formula (1);
The color conversion composition according to any one of claims 1 to 8, characterized by:

(X is C—R ⁷ or N. R ¹ to R ⁹ may be the same or different and are hydrogen, alkyl groups, cycloalkyl groups, heterocyclic groups, alkenyl groups, cycloalkenyl groups, alkynyl group, hydroxyl group, thiol group, alkoxy group, alkylthio group, arylether group, arylthioether group, aryl group, heteroaryl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group , a nitro group, a silyl group, a siloxanyl group, a boryl group, a sulfo group, a phosphine oxide group, and condensed rings and aliphatic rings formed between adjacent substituents.) X in the general formula (1) is C—R ⁷ ,
wherein R ⁷ is a group represented by general formula (2);
The color conversion composition according to claim 9, characterized by:

(r is hydrogen, an alkyl group, a cycloalkyl group, a heterocyclic group, an alkenyl group, a cycloalkenyl group, an alkynyl group, a hydroxyl group, a thiol group, an alkoxy group, an alkylthio group, an aryl ether group, an arylthioether group, an aryl group, a hetero aryl group, halogen, cyano group, aldehyde group, carbonyl group, carboxyl group, ester group, carbamoyl group, amino group, nitro group, silyl group, siloxanyl group, boryl group, sulfo group, selected from the group consisting of phosphine oxide group .k is an integer of 1 to 3. When k is 2 or more, r may be the same or different.) R ¹ , R ³ , R ⁴ and R ⁶ in the general formula (1), which may be the same or different, are substituted or unsubstituted phenyl groups;
The color conversion composition according to claim 9 or 10, characterized by: R ¹ , R ³ , R ⁴ and R ⁶ in the general formula (1), which may be the same or different, are substituted or unsubstituted alkyl groups;
The color conversion composition according to claim 9 or 10, characterized by: At least one of R ² and R ⁵ in the general formula (1), which may be the same or different, is an electron-withdrawing group,
The color conversion composition according to any one of claims 9 to 12, characterized by: R ⁸ and R ⁹ in the general formula (1), which may be the same or different, are fluorine or cyano groups,
The color conversion composition according to any one of claims 9 to 13, characterized by: The m kinds of organic light-emitting materials contain the following light-emitting material (a) and light-emitting material (b):
15. The color conversion composition according to any one of claims 1 to 14, characterized by:
Luminescent material (a): A luminescent material that emits light with a peak wavelength of 500 nm or more and 580 nm or less by using excitation light with a wavelength of 400 nm or more and 500 nm or less. A luminescent material that emits light having a peak wavelength of 580 nm or more and 750 nm or less by being excited by at least one of excitation light in the range of 500 nm to 580 nm and excitation light in the range of 500 nm to 580 nm. A color conversion layer comprising a cured layer of the color conversion composition according to any one of claims 1 to 15,
A color conversion sheet characterized by: including two or more color conversion layers,
At least one of the two or more color conversion layers is a color conversion layer comprising a cured layer of the color conversion composition according to any one of claims 1 to 15.
A color conversion sheet characterized by: a light source;
the color conversion composition according to any one of claims 1 to 15 or the color conversion sheet according to claim 16 or 17;
A light source unit comprising: The light source is a light-emitting diode having a maximum emission in a wavelength range of 400 nm or more and 500 nm or less.
19. The light source unit according to claim 18, characterized by: A light source unit according to claim 18 or 19,
A display characterized by: A light source unit according to claim 18 or 19,
A lighting device characterized by:

Images