WO2021162024A1

WO2021162024A1 - Method for producing wavelength conversion substrate, wavelength conversion substrate, and display

Info

Publication number: WO2021162024A1
Application number: PCT/JP2021/004890
Authority: WO
Inventors: 谷野貴広; 梶野佳範; 石塚雅敏
Original assignee: 東レ株式会社
Priority date: 2020-02-13
Filing date: 2021-02-10
Publication date: 2021-08-19
Also published as: CN114981690A; JPWO2021162024A1; KR20220137867A

Abstract

A method for producing a wavelength conversion substrate having a substrate, a light shielding layer, a partition wall, and a wavelength conversion layer, wherein openings in the partition wall have a striped shape, the light shielding layer has a structure in which the openings and light shielding sections alternate repeatedly in the stripe direction in one of the stripes of the striped shape, the opening ratio of the light shielding layer in the one stripe is 5-70%, and said method for producing a wavelength conversion substrate includes a step in which a wavelength conversion paste is applied by nozzle so as to obtain a wavelength conversion layer having the same composition in the openings in the light shielding layer and in the light shielding sections of the light shielding layer in the one stripe.　The present invention provides: a wavelength conversion substrate that makes it possible to easily form a wavelength conversion layer and in which it possible to suppress the diffusion of light to adjacent subpixels; a display using the wavelength conversion substrate; and a method for producing the wavelength conversion substrate.

Description

Wavelength conversion board manufacturing method, wavelength conversion board, and display

The present invention relates to a method for manufacturing a wavelength conversion substrate, a wavelength conversion substrate, and a display.

In recent years, with the development of information terminal devices such as smartphones and tablets and the high definition of flat panel displays such as televisions, the demand for higher performance of displays has further increased. Among them, wavelength conversion type organic light emitting diode (OLED) displays and light emitting diode (LED) displays are attracting attention as high-performance displays. These displays use OLEDs or LEDs driven by an active matrix as a light source, and display in full color by changing at least a part of the light with a wavelength conversion material, and are excellent in contrast and color reproducibility.

As a method of using an OLED as a light source, a method of using an OLED that emits blue light is known (Patent Document 1). In this case, the blue subpixel transmits and scatters the light from the OLED without wavelength conversion, and the green and red subpixels change the blue light from the OLED to green and red, respectively, by the wavelength conversion material.

As a method of using an LED as a light source, a blue emitting LED is used as in the OLED, and in addition to a method of changing a part of light to red and green with a wavelength conversion material, an ultraviolet emitting LED is used and a wavelength conversion material is used. A method of changing the color to blue, green, or red is known (Patent Document 2).

In these wavelength conversion type displays, the wavelength conversion material is patterned and arranged in the cells separated by the partition wall on the substrate in which the partition wall is formed with the size corresponding to the OLED or the subpixel of the LED as the light source. There is a need. As a method for patterning a wavelength conversion material, a photolithography method and an inkjet method (Patent Document 3) are known.

Special Table 2006-501617 Special table 2016-523450 International Publication No. 2018/123103

However, in the photolithography method, the wavelength conversion material is applied to the entire surface, the predetermined position is exposed, and then most of the wavelength conversion material is removed by development. Therefore, the loss of the wavelength conversion material is large, and the process also repeats the exposure and development a plurality of times. There were challenges that were necessary and complicated. In addition, the inkjet method is excellent in material efficiency because the wavelength conversion layer can be formed only at a desired position. However, in order to apply an ink containing a wavelength conversion material by inkjet, it is necessary to design the ink to have a low viscosity. There is a problem that particle components such as a wavelength conversion material settle in the ink and the inkjet nozzle is easily clogged.

On the other hand, as a paste coating method, a nozzle coating method is known in which the paste is continuously discharged from the discharge port of the coating head and the position of the coating head is moved relative to the substrate. FIG. 1 shows a schematic diagram showing an example of a method of applying a wavelength conversion paste using a coating head having a plurality of ejection ports by a nozzle coating method. A space (manifold) for storing the paste 5 is provided inside the coating head 4, and compressed air whose pressure is controlled is introduced through a pressure pipe 6 connected to the space while moving relative to the substrate 3. This is a coating method in which the paste 5 is applied by discharging the paste 5 from the discharge port 7. In the nozzle coating method, the viscosity of the paste can be higher than that in the inkjet method. Therefore, by designing the paste to have a high viscosity, clogging of the nozzle due to sedimentation of particle components can be suppressed.

However, in the nozzle coating method, the paste is applied while being continuously ejected, so that the paste is applied in stripes. Here, when the partition shape suitable for the nozzle coating method is a linear shape having a uniform opening width in the direction parallel to the stripe, light leakage to subpixels adjacent to the subpixel in the direction parallel to the stripe is remarkably generated. There was a problem to do. Even in the case of a grid shape, if the partition wall in the direction orthogonal to the stripe (hereinafter referred to as the horizontal partition wall) has a narrow partition wall width, light to subpixels adjacent to the stripe in the direction parallel to the stripe is similar to the stripe shape. Leakage occurred, and when it was thick, there was a problem that the paste ran on the partition wall. Further, in any of the above, when the partition wall width of the partition wall in the direction parallel to the stripe is narrow, there is a problem that light leaks to the subpixels of the openings adjacent in the direction orthogonal to the stripe and the colors are mixed.

Therefore, an object of the present invention is to provide a wavelength conversion substrate capable of easily forming a wavelength conversion layer and further suppressing light diffusion to adjacent subpixels.

In order to solve the above problems, the method for manufacturing a wavelength conversion substrate of the present invention has any of the following configurations. That is,
A method for manufacturing a wavelength conversion substrate having a substrate, a light-shielding layer, a partition wall, and a wavelength conversion layer, wherein the opening of the partition wall has a stripe shape, and in one stripe of the stripe shape, the light-shielding layer is in the stripe direction. It has a structure in which an opening and a light-shielding portion are repeated, and the aperture ratio of the light-shielding layer in the one stripe is 5 to 70%, and further, in the one stripe, the opening of the light-shielding layer and the light-shielding portion of the light-shielding layer. A method for manufacturing a wavelength conversion substrate, which comprises a step of nozzle-coating a wavelength conversion paste so as to have the wavelength conversion layer having the same composition, or
A method for manufacturing a wavelength conversion substrate having a substrate, a light-shielding layer, a partition wall, and a wavelength conversion layer, wherein the opening of the partition wall has a striped shape, and in one stripe of the stripe shape, the opening of the partition wall is the stripe. It has a structure in which at least two or more patterns are repeated in a direction, at least one of the repeating patterns has an opening in the light-shielding layer at the opening of the partition wall, and at least one of the repeating patterns has an opening. The light-shielding layer has substantially no opening in the opening of the partition wall, and the light-shielding layer has an opening in the opening of the partition wall and the light-shielding layer has an opening in the opening of the partition wall. This is a method for manufacturing a wavelength conversion substrate, which comprises a step of applying a wavelength conversion paste to the opening of the wavelength conversion substrate so as to have the wavelength conversion layer having the same composition in any of the portions having the same composition.

The wavelength conversion substrate of the present invention has any of the following configurations. That is,
A wavelength conversion substrate having a substrate, a light-shielding layer, a partition wall, and a wavelength conversion layer, the opening of the partition wall having a stripe shape, and in one stripe of the stripe shape, the light-shielding layer has an opening in the stripe direction. The light-shielding layer has an aperture ratio of 5 to 70% in the one stripe, and either the opening of the light-shielding layer or the light-shielding portion of the light-shielding layer in the one stripe. Also, a wavelength conversion substrate having the wavelength conversion layer having the same composition, or
A wavelength conversion substrate having a substrate, a light-shielding layer, a partition wall, and a wavelength conversion layer, in which the opening of the partition wall is striped, and in one stripe of the stripe shape, the opening of the partition wall is in the stripe direction. It has a structure in which at least two or more patterns are repeated, at least one of the repeating patterns also has an opening in the light-shielding layer at the opening of the partition, and at least one of the repeating patterns has the partition. The light-shielding layer has substantially no opening in the opening of the partition wall, and further, the light-shielding layer has an opening in the opening of the partition wall and the light-shielding layer has an opening in the opening of the partition wall. A wavelength conversion substrate having the wavelength conversion layer having the same composition in any of the places where the wavelength is not formed.

The display of the present invention has the following configuration. That is,
The wavelength conversion substrate and a display having an OLED or an LED as a light source.

In the method for manufacturing a wavelength conversion substrate of the present invention, it is preferable that the aperture ratio of the partition wall is 50 to 95% in the at least one stripe.

In the method for manufacturing a wavelength conversion substrate of the present invention, it is preferable that the thickness H of the partition wall, the thickness T _{1 of the} light-shielding layer, and the thickness T ₂ of the wavelength conversion layer satisfy the following equations (1) and (2).

H / 100 ≤ T ₁ ≤ H / 3 (1)
H / 2 ≤ T ₂ ≤ H (2)
In the method for manufacturing a wavelength conversion substrate of the present invention, it is preferable to further have a flattening layer between the partition wall and the light-shielding layer.

In the method for manufacturing a wavelength conversion substrate of the present invention, it is preferable that the wavelength conversion layer contains a resin.

In the method for manufacturing a wavelength conversion substrate of the present invention, the porosity of the wavelength conversion layer is preferably 0.01 to 10%.

In the method for manufacturing a wavelength conversion substrate of the present invention, the reflectance of the light-shielding layer is preferably 0.1 to 10%.

In the method for manufacturing a wavelength conversion substrate of the present invention, it is preferable that the wavelength conversion layer contains an inorganic phosphor.

In the method for manufacturing a wavelength conversion substrate of the present invention, it is preferable that the wavelength conversion layer contains quantum dots.

The method for manufacturing a wavelength conversion substrate of the present invention can provide a wavelength conversion substrate capable of easily forming a wavelength conversion layer and further suppressing light diffusion to adjacent subpixels.

It is a schematic diagram which showed the paste application method by the nozzle application method. It is a top view which shows one aspect of a light-shielding layer. It is a top view which shows one aspect of a partition wall. It is a top view which shows one aspect of the substrate with a partition wall. It is a top view which shows one aspect of the wavelength conversion substrate of this invention which formed the wavelength conversion layer on the substrate with a partition wall shown in FIG. FIG. 5 is a cross-sectional view taken along the line AA'of the wavelength conversion substrate shown in FIG. FIG. 5 is a cross-sectional view taken along the line BB'of the wavelength conversion substrate shown in FIG. It is a top view which shows one aspect of a partition wall. It is a top view which shows one aspect of a light-shielding layer. It is a top view which shows one aspect of a partition wall. It is a top view which shows one aspect of a partition wall. It is a top view which shows one aspect of a partition wall. It is a top view which shows one aspect of a partition wall. It is a top view which shows one aspect of a light-shielding layer.

The method for manufacturing a wavelength conversion substrate of the present invention includes a step of nozzle-applying a wavelength conversion paste so as to have a wavelength conversion layer at an opening of a partition wall of a substrate with a partition wall having a substrate, a light-shielding layer, and a partition wall.

In the present invention, the substrate has a function as a support in a substrate with a partition wall. Examples of the substrate include a glass plate, a resin plate, a resin film, and the like. As the material of the glass plate, non-alkali glass is preferable. As the material of the resin plate and the resin film, polyester, (meth) acrylic polymer, transparent polyimide, polyether sulfone and the like are preferable. The thickness of the glass plate and the resin plate is preferably 1 mm or less, preferably 0.8 mm or less. The thickness of the resin film is preferably 100 μm or less.

In the present invention, the substrate with partition walls has a light-shielding layer on the substrate. Further, in the present invention, on the surface of the substrate on the side having the light-shielding layer, the portion where the light-shielding layer is not formed, which is partitioned by the light-shielding layer, is referred to as an opening of the light-shielding layer. Further, the portion where the light-shielding layer is formed is referred to as a light-shielding portion of the light-shielding layer.

In the present invention, the light-shielding layer preferably absorbs visible light. By absorbing visible light, the light emitted from the OLED or LED and the light after the light is converted by the wavelength conversion material described later are transmitted through the light-shielding portion of the light-shielding layer, so that the light-emitting point is blurred. Can be suppressed. Further, since the light-shielding layer absorbs visible light, it is possible to suppress the reflected light when the display is irradiated with external light, so that the contrast of the appearance of the display is improved. Further, as will be described later, it is possible to suppress light leakage to subpixels adjacent in a direction parallel to the stripe. When the LED is an LED that emits ultraviolet light, it is preferable to absorb ultraviolet light in addition to visible light.

The light-shielding layer of the present invention preferably contains a black pigment. The black pigment is not particularly limited, and for example, carbon black, titanium black, chromium oxide, iron oxide, aniline black, perylene pigment or C.I. I. Examples thereof include a black pigment such as Solvent Black 123, an inorganic black pigment such as a composite oxide of carbon black, titanium, manganese, iron, copper or cobalt coated with a resin, or a combination of an organic pigment and a black pigment. Carbon black, titanium nitride, and titanium oxynitride are preferable because they have high light-shielding properties.

The optical density (OD) value of the light-shielding layer of the present invention is preferably 2 or more, and more preferably 3 or more at a wavelength of 550 nm.

In the present invention, the substrate with a partition wall has a partition wall on the substrate. Further, in the present invention, on the surface of the substrate on the side having the partition wall, the portion where the partition wall is not formed is referred to as the opening of the partition wall.

In the present invention, the opening partitioned by the partition has a striped shape. The striped shape means a shape in which substantially linear openings are continuous in a direction parallel to the straight line direction, or a shape in which the openings are repeated. Since the opening has a striped shape, the wavelength conversion layer can be easily formed by the nozzle coating method. The substantially straight line shape is not limited to a perfect straight line shape, and may be meandering or deviated in a direction orthogonal to the straight line direction within a range that does not intersect the center line of the adjacent striped opening. Further, the substantially linear opening may be continuous or discontinuous with a horizontal partition wall. Further, the opening shape is not particularly limited, and examples thereof include a quadrangle, a circle, and an ellipse. In the present invention, the stripe direction or the direction parallel to the stripe means the direction parallel to the linear direction.

It is preferable that the partition wall has a function of preventing light from being transmitted from a certain subpixel to an adjacent subpixel. By having this function, it is possible to suppress color mixing due to light leakage to adjacent sub-pixels.

FIG. 2 shows a top view of one aspect of the light-shielding layer, and FIG. 3 shows a top view of one aspect of the partition wall. Further, FIG. 4 shows a top view of one aspect of a substrate with a partition wall in which the partition wall of FIG. 3 is formed on the substrate on which the light-shielding layer of FIG. 2 is formed. Further, FIG. 5 shows a top view of one aspect of the wavelength conversion substrate of the present invention in which a wavelength conversion layer is formed on the substrate with a partition wall shown in FIG. Further, FIGS. 6 and 7 show cross-sectional views of AA'and BB' as an example of the cross-sectional views of the wavelength conversion substrate of FIG. 5 in the direction orthogonal to the stripe direction. A light-shielding layer 8 and a patterned partition wall 1 are provided on the substrate 3, and a wavelength conversion layer 9 is provided in an opening partitioned by the partition wall.

In one aspect of the present invention, the opening of the partition wall has a striped shape, and in one stripe of the striped shape, the light-shielding layer has a structure in which the opening and the light-shielding portion are repeated in the stripe direction, and the light-shielding portion in the one stripe. It is essential that the aperture ratio of the layer is 5 to 70%. Here, the aperture ratio of the light-shielding layer in one stripe is the area of the portion where the light-shielding portion is not formed in one repeating unit having a structure in which the light-shielding layer repeats the opening and the light-shielding portion in the stripe direction. The ratio divided by the total area of. If the aperture ratio of the light-shielding layer is less than 5%, the brightness of the display may be low. On the other hand, if it is larger than 70%, light leakage to subpixels adjacent in the direction parallel to the stripe may occur remarkably.

In the present invention, the aperture ratio of the partition wall is preferably 50 to 95%. Here, the aperture ratio of the partition wall means a ratio obtained by dividing the area of the partition wall forming portion in the display area of the display by the total area of the display area of the display. When the aperture ratio is smaller than 50%, when the wavelength conversion paste is applied to the nozzle, the paste may easily run on the top of the partition wall. Further, when the aperture ratio is larger than 95%, light may easily leak to pixels adjacent to the pixels in the direction orthogonal to the stripe direction.

In the present invention, the opening of the partition wall may be continuous in the direction parallel to the stripe, or may have a horizontal partition wall and may be discontinuous. When the partition wall has a function of preventing light transmission / scattering, the horizontal partition wall may suppress the scattering of light in the direction parallel to the stripe. However, when the partition width of the transverse partition is large, a part of the wavelength conversion layer formed by the nozzle coating method may also exist on the transverse partition, so that the opening for the length in the direction parallel to the stripe of the repeating unit. The ratio of the length in the direction parallel to the stripe is preferably 80% or more. More preferably, it is 90% or more.

The partition wall preferably has a reflectance of 20 to 90% per 10 μm thickness at a wavelength of 550 nm. By setting the reflectance to 20% or more, the brightness of the display can be improved by utilizing the reflection on the side surface of the partition wall. On the other hand, the reflectance is preferably 90% or less from the viewpoint of improving the partition wall pattern forming accuracy. Here, the thickness of the partition wall refers to the length of the partition wall in the direction perpendicular to the substrate (height direction). In the case of the partition wall-equipped substrate shown in FIGS. 6 and 7, the thickness of the partition wall 1 is represented by reference numeral H. The length of the partition wall in the horizontal direction is the width of the partition wall. In the case of the partition wall-equipped substrate shown in FIGS. 6 and 7, the width of the partition wall 1 is represented by reference numeral L. In FIG. 3, the direction parallel to the stripe is indicated by an upward arrow (the same applies to FIGS. 8, 10 to 13).

The thickness of the partition wall is preferably larger than the thickness of the cured product of the wavelength conversion paste when the cured product of the wavelength conversion paste is contained in the cell of the substrate with the partition wall. Specifically, the thickness of the partition wall 1 is preferably 0.5 μm or more, and more preferably 5 μm or more. On the other hand, from the viewpoint of more efficiently extracting light emission at the bottom of the layer containing the color conversion light emitting material, the thickness of the partition wall is preferably 100 μm or less, more preferably 70 μm or less, still more preferably 50 μm or less. Further, the width of the partition wall may be sufficient to improve the brightness by utilizing the light reflection on the side surface of the partition wall and suppress the color mixing of the light emitted from the cured product of the adjacent wavelength conversion paste due to light leakage. Specifically, the width of the partition wall is preferably 5 μm or more, and more preferably 10 μm or more.

In the present invention, the width of the partition wall opening in the direction orthogonal to the stripe is referred to as the partition wall opening width. In one aspect of the present invention, the shape of the partition wall has a portion where the opening width of the partition wall is large, a portion where the opening width of the partition wall is small, or a portion where a horizontal partition wall exists, and a portion where the opening width changes. Or, it is essential to have a structure in which two or more types of patterns separated by a horizontal partition wall are repeated in a direction parallel to the stripe. Further, at least one of the above-mentioned repeating patterns of the partition wall also has an opening in the light-shielding layer at the opening of the partition wall, and at least one of the other repeating patterns has a substantially light-shielding layer at the opening of the partition wall. It is essential that there is no opening in the. Here, "substantially having no opening" means that defects such as pinholes in the light-shielding layer and minute openings in the light-shielding layer at the end of the repeating unit due to misalignment between the partition wall and the light-shielding layer are included. It means that you may have it. With such a configuration, when the OLED or LED is arranged at a location corresponding to the opening of the light-shielding layer and emitted, the light emitted from the OLED or the LED and the light are converted by the wavelength conversion layer described later. Since the light after being light is reflected by the partition wall and concentrated in the place where the opening of the light-shielding layer exists, the probability that the light is taken out from the opening of the light-shielding layer is improved, and the brightness of the display is improved.

In the present invention, it is preferable that the light-shielding layers also have openings in the opening of the partition wall in a staggered manner between adjacent stripes. In such a configuration, the width of the partition wall in the direction orthogonal to the stripe becomes large, so that color mixing can be effectively suppressed.

In one aspect of the present invention, the light-shielding layer has a structure in which an opening and a light-shielding portion are repeated in the stripe direction of the partition wall, and in the one stripe, both the opening of the light-shielding layer and the light-shielding portion of the light-shielding layer are formed. It is essential to have the wavelength conversion layer having the same composition. Further, in one aspect of the present invention, there is at least one pattern of partition wall opening in which the light-shielding layer has an opening in the partition wall opening, and at least one in which the light-shielding layer does not have an opening in the partition wall opening. It is essential to have a wavelength conversion layer of the same composition in each of the openings of the partition wall of the species pattern. With such a configuration, the wavelength conversion layer absorbs light in the light-shielding portion of the light-shielding layer or a place where the light-shielding layer does not have an opening, and the light scattered by the wavelength conversion layer is absorbed by the light-shielding layer. By doing so, the diffusion of light in the direction parallel to the stripe is suppressed, and the light leakage to the subpixels adjacent in the direction parallel to the stripe can be efficiently suppressed. In the method for manufacturing a wavelength conversion substrate of the present invention, by applying the wavelength conversion paste to the nozzle, the wavelength conversion layer is formed in the light-shielding portion of the light-shielding layer and the portion having no opening in the light-shielding layer. The effect that the wavelength conversion layer can be easily formed and the light diffusion to the adjacent subpixels can be suppressed can be obtained.

It should be noted that the wavelength conversion layer rides on the top of the partition wall, and the light-shielding portion of the light-shielding layer does not have the wavelength conversion layer at the portion where the partition wall is interposed between the light-shielding portion of the light-shielding layer and the wavelength conversion layer. ..

In the present invention, the wavelength conversion layer contains a wavelength conversion material. In the present invention, the wavelength conversion material refers to a material having a wavelength conversion property that absorbs an electromagnetic wave and emits an electromagnetic wave having a wavelength different from the wavelength of the absorbed electromagnetic wave. A wavelength conversion substrate having a wavelength conversion material can be patterned and applied to prepare a wavelength conversion substrate, which can be combined with an OLED light source or an LED light source to form a full-color display.

As the wavelength conversion material, it is preferable to use an inorganic phosphor and / or an organic phosphor. For example, in the case of a display in which an OLED that emits blue light and a wavelength conversion substrate are combined, a red phosphor that is excited by blue excitation light and emits red fluorescence is placed in a region corresponding to the red subpixel. It is preferable to use it as a wavelength conversion material, and in the region corresponding to the green subpixel, it is preferable to use a green phosphor that is excited by blue excitation light and emits green fluorescence as the wavelength conversion material, and the blue subpixel. It is preferable not to use a wavelength conversion material in the region corresponding to. Similarly, the wavelength conversion substrate of the present invention can also be used for a display in which a blue LED or an ultraviolet light emitting LED corresponding to each subpixel is used as a backlight. The light emission of each sub-pixel can be turned ON / OFF by driving an OLED or an active matrix of LEDs.

Inorganic phosphors emit various colors such as green and red. Examples of the inorganic phosphor include those excited by excitation light having a wavelength of 400 to 500 nm and having a peak in the emission spectrum in the region of 500 to 700 nm, inorganic semiconductor fine particles called quantum dots, and the like. Examples of the shape of the former inorganic phosphor include a spherical shape and a columnar shape. Examples of such inorganic phosphors include YAG-based phosphors, TAG-based phosphors, sialon-based phosphors, Mn ⁴⁺ activated fluoride complex phosphors, and the like. Two or more of these may be used.

Among these, quantum dots are preferable. Since quantum dots have sharper peaks in the emission spectrum than other phosphors, the color reproducibility of the display can be improved.

Examples of the quantum dot material include semiconductors of group II-IV, group III-V, group IV-VI, and group IV. Examples of these inorganic semiconductors include Si, Ge, Sn, Se, Te, B, C (including diamond), P, BN, BP, BAs, AlN, AlP, AlAs, AlSb, GaN, GaP, GaAs, GaSb, InN, InP, InAs, InSb, ZnO, ZnS, ZnSe, ZnTe, CdS, CdSe, CdSeZn, CdTe, HgS, HgSe, HgTe, BeS, BeSe, BeTe, MgS, MgSe, GeS, GeS Examples thereof include SnSe, SnTe, PbO, PbS, PbSe, PbTe, CuF, CuCl, CuBr, CuI, Si ₃ N ₄ , Ge ₃ N ₄ , Al ₂ O ₃ . Two or more of these may be used.

The quantum dots may contain a p-type dopant or an n-type dopant. Further, the quantum dots may have a core-shell structure. In the core-shell structure, any suitable functional layer (single layer or multiple layers) may be formed around the shell depending on the purpose, and the shell surface may be surface-treated and / or chemically modified. ..

Examples of the shape of the quantum dot include a spherical shape, a columnar shape, a flaky shape, a plate shape, an amorphous shape, and the like. The average particle size of the quantum dots can be selected according to the desired emission wavelength, and is preferably 1 to 30 nm. When the average particle size of the quantum dots is 1 to 10 nm, the peaks in the emission spectrum can be sharpened in each of blue, green, and red. For example, when the average particle size of the quantum dots is about 2 nm, blue light is emitted, when it is about 3 nm, green light is emitted, and when it is about 6 nm, red light is emitted. The average particle size of the quantum dots is preferably 2 nm or more, preferably 8 nm or less. The average particle size of quantum dots can be measured by a dynamic light scattering method. Examples of the device for measuring the average particle size include a dynamic light scattering photometer DLS-8000 (manufactured by Otsuka Electronics Co., Ltd.).

Examples of the organic phosphor include a pyrromethene derivative having a basic skeleton represented by the following structural formula (A) as a phosphor that is excited by blue excitation light and emits red fluorescence, and a green one that is excited by blue excitation light. Examples of the fluorescent substance that emits fluorescence include a pyrromethene derivative having a basic skeleton represented by the following structural formula (B). Other examples include perylene-based derivatives, porphyrin-based derivatives, oxazine-based derivatives, and pyrazine-based derivatives that emit red or green fluorescence depending on the selection of the substituent. Two or more of these may be contained. Among these, a pyrromethene derivative is preferable because of its high quantum yield. The pyrromethene derivative can be obtained, for example, by the method described in JP-A-2011-241160.

Since the organic phosphor is soluble in a solvent, a layer containing a wavelength conversion material having a desired thickness can be easily formed.

The wavelength conversion layer of the present invention may contain light-scattering particles. By containing the light-scattering particles, blue light and ultraviolet light are scattered in the wavelength conversion layer, so that the optical path length becomes long, and the light conversion efficiency of the wavelength conversion material can be improved.

The light scattering particles are preferably barium sulfate, aluminum oxide, zirconium oxide, zinc oxide, or titanium oxide. Two or more of these may be contained.

The refractive index of the light scattering particles at a wavelength of 587.5 nm is preferably 1.60 to 2.70. By setting the refractive index of the light-scattering particles to 1.60 or more, the scattering property of blue light or ultraviolet light in the wavelength conversion layer by the light-scattering particles is improved, and the light conversion efficiency by the wavelength conversion material is likely to be improved. .. In addition, the light scattered by the wavelength conversion layer is absorbed by the light-shielding layer, so that the diffusion of light in the direction parallel to the stripe is suppressed, and light leakage to the subpixels adjacent in the direction parallel to the stripe is efficient. Can be suppressed. On the other hand, by setting the refractive index of the light-scattering particles to 2.70 or less, excessive scattering by the light-scattering particles is suppressed, and the emitted light after wavelength conversion can be easily taken out of the cell. When two or more kinds of light scattering particles are contained, it is preferable that the refractive index of at least one kind is in the above range.

The content of the light scattering particles is preferably 1% by weight or more, more preferably 3% by weight or more, and further preferably 5% by weight or more in the solid content from the viewpoint of further improving the light conversion efficiency. On the other hand, the content of the light-scattering particles is preferably 70% by weight or less, more preferably 60% by weight or less, and 50% by weight or less in the solid content from the viewpoint of suppressing a decrease in luminous efficiency due to concentration quenching of the wavelength conversion material. Is even more preferable. The solid content here means all the components contained in the wavelength conversion paste except for volatile components such as a solvent. The amount of solid content can be determined by heating the wavelength conversion paste at 150 ° C. for 1 hour and measuring the residue obtained by evaporating the volatile components.

In the present invention, the wavelength conversion layer is preferably formed by curing the wavelength conversion paste. The wavelength conversion paste is a paste material containing a wavelength conversion material, and can be easily applied to a substrate with a partition wall by a nozzle coating method by appropriately designing the composition. The method of curing the wavelength conversion paste is not particularly limited, but a method of curing a wavelength conversion paste containing a polymerizable compound with heat or light, or a method of volatilizing a solvent from a wavelength conversion paste containing a solvent and curing the solvent. And so on.

In the present invention, the wavelength conversion paste may contain a monomer as a polymerizable compound. The monomer in the present invention refers to a compound that polymerizes with an active species generated by the reaction of a polymerization initiator described later.

The monomer in the present invention is preferably a compound having an ethylenically unsaturated double bond in the molecule. The monomer preferably has two or more ethylenically unsaturated double bonds in the molecule. Considering the ease of radical polymerization, the monomer preferably has a (meth) acrylic group. The double bond equivalent of the monomer is preferably 400 g / mol or less from the viewpoint of further improving the sensitivity in pattern processing.

Examples of the monomer include diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, dipropylene glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, diethylene glycol dimethacrylate, and triethylene. Glycol dimethacrylate, tetraethylene glycol dimethacrylate, polypropylene glycol dimethacrylate, trimethylolpropandiacrylate, trimethylolpropanetriacrylate, trimethylolpropanedimethacrylate, trimethylolpropanetrimethacrylate, 1,3-butanediol diacrylate, 1, 3-Butanediol Dimethacrylate, Neopentyl Glycol Diacrylate, 1,4-Butanediol Diacrylate, 1,4-Butanediol Dimethacrylate, 1,6-Hexanediol Diacrylate, 1,9-Nonanediol Dimethacrylate, 1 , 10-decanediol dimethacrylate, dimethylol-tricyclodecanediacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, pentaerythritol trimethacrylate, pentaerythritol tetramethacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, trypenta Ellislitol heptaacrylate, trypentaerythritol octaacrylate, tetrapentaerythritol nonaacrylate, tetrapentaerythritol decaacrylate, pentapentaerythritol undecaacrylate, pentapentaerythritol dodecaacrylate, trypentaerythritol heptamethacrylate, trypentaerythritol octamethacrylate, tetrapentaerythritol Examples thereof include nona methacrylate, tetrapentaerythritol decamethacrylate, pentapentaerythritol undecamethacrylate, pentapentaerythritol dodecamethacrylate, and dimethyrole-tricyclodecanediacrylate. Two or more of these may be contained.

In the present invention, the content of the monomer in the wavelength conversion paste is preferably 1% by weight or more, more preferably 10% by weight or more, and 30% by weight or more in the solid content from the viewpoint of increasing the solid content of the wavelength conversion paste. Is even more preferable. On the other hand, from the viewpoint of stabilizing the discharge from the nozzle, the content of the monomer is preferably 80% by weight or less, more preferably 70% by weight or less in the solid content.

In the present invention, the wavelength conversion paste may contain a polymerization initiator. By containing the polymerization initiator and the monomer, the polymerization initiator is reacted by light irradiation or heating, so that the polymerization of the monomer proceeds by the active species generated from the polymerization initiator and the wavelength conversion paste is cured. Can be done.

The polymerization initiator is any radical initiator or cation initiator, that is, any one that reacts with light (including ultraviolet rays and electron beams) or heat to generate active species such as radicals and cations. good. Among these, a radical initiator is preferable. Examples of the polymerization initiator include 2-methyl- [4- (methylthio) phenyl] -2-morpholinopropane-1-one and 2-dimethylamino-2- (4-methylbenzyl) -1- (4-). Α-Aminoalkylphenone compounds such as morpholin-4-yl-phenyl) -butane-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1; 2,4 , 6-trimethylbenzoylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, bis (2,6-dimethoxybenzoyl)-(2,4,4-trimethylpentyl) -phosphine oxide, etc. Acylphosphine oxide compounds; 1-phenyl-1,2-propanedione-2- (O-ethoxycarbonyl) oxime, 1- [4- (phenylthio) phenyl] octane-1,2-dione = 2- (O-benzoyl) Oxime)], 1-phenyl-1,2-butadion-2- (O-methoxycarbonyl) oxime, 1,3-diphenylpropanthrion-2- (O-ethoxycarbonyl) oxime, etanone, 1- [9-ethyl Oxime ester compounds such as -6- (2-methylbenzoyl) -9H-carbazole-3-yl]-, 1- (O-acetyloxime); benzyl ketal compounds such as benzyl dimethyl ketal; 2-hydroxy-2-methyl -1-Phenylpropan-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 4- (2-hydroxyethoxy) phenyl- (2-hydroxy-2-propyl) ) Ketones, α-hydroxyketone compounds such as 1-hydroxycyclohexyl-phenylketone; benzophenone, 4,4-bis (dimethylamino) benzophenone, 4,4-bis (diethylamino) benzophenone, methyl O-benzoyl benzoate, 4- Phenylbenzophenone, 4,4-dichlorobenzophenone, hydroxybenzophenone, 4-benzoyl-4'-methyl-diphenylsulfide, alkylated benzophenone, 3,3', 4,4'-tetra (t-butylperoxycarbonyl) benzophenone, etc. Benzoyl compounds of; 2,2-diethoxyacetophenone, 2,3-diethoxyacetophenone, 4-t-butyldichloroacetophenone, benzalacetophenone, 4-azidobenzalacetopheno Acetphenone compounds such as 2-phenyl-2-oxyacetate compounds; ethyl 4-dimethylaminobenzoate, 4-dimethylaminobenzoic acid (2-ethyl) hexyl, ethyl 4-diethylaminobenzoate, Examples thereof include benzoic acid ester compounds such as 2-benzoyl methyl benzoate. Two or more of these may be contained.

In the present invention, the wavelength conversion paste suppresses coloring due to the polymerization initiator, so that the 2,4,6-trimethylbenzoylphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphin oxide, bis (2) , 6-Dimethoxybenzoyl)-(2,4,4-trimethylpentyl) -phosphine oxide and the like, preferably containing an acylphosphine oxide-based polymerization initiator.

In the present invention, the content of the polymerization initiator in the wavelength conversion paste is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, based on the solid content, from the viewpoint of efficiently advancing radical curing. On the other hand, from the viewpoint of suppressing elution of the residual polymerization initiator and further improving yellowing, the content of the polymerization initiator is preferably 20% by weight or less, more preferably 10% by weight or less in the solid content.

In the present invention, the wavelength conversion paste may appropriately contain a polymer, a solvent, a dispersant and the like.

In the present invention, when the wavelength conversion paste contains a polymer, the polymer includes, for example, a silicone resin such as polyvinyl acetate, polyvinyl alcohol, ethyl cellulose, methyl cellulose, polyethylene, polymethyl siloxane or polymethyl phenyl siloxane, polystyrene, butadiene / styrene. Preferred examples include copolymers, polystyrene, polyvinylpyrrolidone, polyamides, high molecular weight polyethers, copolymers of ethylene oxide and propylene oxide, polyacrylamides or acrylic resins.

In the present invention, when the wavelength conversion paste contains a solvent, as the solvent, for example, methanol, ethanol, propanol, isopropanol, butanol, isobutanol, t-butanol, pentanol, 4-methyl-2-pentanol, 3 -Alcohols such as methyl-2-butanol, 3-methyl-3-methoxy-1-butanol, diacetone alcohol; glycols such as ethylene glycol and propylene glycol; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, propylene glycol Ethers such as monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, propylene glycol mono-t-butyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol dibutyl ether, diethyl ether; methyl ethyl ketone , Acetylacetone, methylpropylketone, methylbutylketone, methylisobutylketone, diisobutylketone, cyclopentanone, 2-heptanone and other ketones; dimethylformamide, dimethylacetamide and other amides; ethylacetate, propylacetate, butylacetate, isobutyl Acetates such as acetate, ethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate, methyl lactate, ethyl lactate, butyl lactate; toluene, xylene, hexane, Aromatic or aliphatic hydrocarbons such as cyclohexane; γ-butyrolactone, N-methyl-2-pyrrolidone, dimethylsulfoxide and the like are preferred.

In the present invention, the viscosity of the wavelength conversion paste is measured when a rheometer (HAAKE MARS; manufactured by Thermo Fisher Scientific Co., Ltd.) is equipped with a Plate P35 TIL manufactured by the same company and the gap is set to 200 μm. The viscosity at a shear rate of 1 sec ^-1 is preferably 1,000 to 500,000 mPa · s. By setting the viscosity to 1,000 mPa · s or more, particle components such as light-scattering particles are less likely to settle even when the paste is stored for a long period of time after preparation. The viscosity is more preferably 3,000 mPa · s or more, and further preferably 5,000 mPa · s or more. Further, by setting the viscosity to 500,000 mPa · s or less, it becomes easy to stably discharge even when pressurized with low-pressure compressed air. The viscosity is more preferably 400,000 mPa · s or less, and even more preferably 300,000 mPa · s or less.

In the present invention, when the wavelength conversion paste contains a dispersant, the dispersant may be, for example, "Disperbyk" (registered trademark) 106, 108, 110, 180, 190, 2001, 2155, 140, 145 (all, commodities). The name, manufactured by Big Chemie Co., Ltd.) and the like are preferably mentioned.

In the present invention, the thickness H of the partition wall, the thickness T _{1 of the} light-shielding layer, and the thickness T ₂ of the wavelength conversion layer preferably satisfy the following equations (1) and (2).
H / 100 ≤ T ₁ ≤ H / 3 (1)
H / 2 ≤ T ₂ ≤ H (2)
In (1), when H / 100> T ₁ , the light-shielding layer may be thin and the light-shielding property may be deteriorated. Further, when T ₁ > H / 3, the light-shielding layer is thick, and when the light passes through the opening of the light-shielding layer, the light is absorbed by the side surface of the light-shielding layer, and the brightness may decrease. In (2), when H / 2> T ₂ , the thickness of the wavelength conversion layer is thin, so that light absorption and scattering in the wavelength conversion layer are less likely to occur, and light leaks to subpixels adjacent in the direction parallel to the stripe. May be more likely to occur. When T ₂ > H, since the wavelength conversion layer is raised above the partition wall, a gap may be formed when the wavelength conversion substrate is bonded to the OLED substrate or the LED substrate, and light may easily leak to the adjacent cell. ..

The wavelength conversion substrate of the present invention is preferably produced by applying a wavelength conversion paste to a substrate with a partition wall by a nozzle coating method and curing the substrate.

In the present invention, when a blue OLED or a blue LED is used as a light source, it is preferable that a paste having the same composition as the wavelength conversion paste is nozzle-coated on the subpixel for blue light emission except that the wavelength conversion layer is not included. .. In particular, from the viewpoint of improving the viewing angle of the display, it is preferable to apply a light scattering paste containing light scattering particles to the nozzle. By applying the light scattering paste to the nozzle to form the light scattering layer, the light scattering paste is formed in the light-shielding portion of the light-shielding layer and the portion having no opening in the light-shielding layer as in the case of the wavelength conversion layer. Therefore, a light-scattering paste can be easily formed, and the light scattered in the light-scattering layer is absorbed by the light-shielding layer to suppress the diffusion of light in the direction parallel to the stripe, and the direction parallel to the stripe. Light leakage to subpixels adjacent to the can be efficiently suppressed.

Next, the display of the present invention will be described. The display of the present invention has the wavelength conversion substrate and a light source. As the light source, a light source selected from a blue OLED, a blue LED, and an ultraviolet light emitting LED capable of driving an active matrix is preferable.

The display of the present invention will be described with reference to an example of a display having the wavelength conversion substrate of the present invention and a blue OLED. A photosensitive polyimide resin is applied onto a glass substrate having a TFT pattern capable of driving an active matrix, and an insulating film is formed by a photolithography method. After sputtering aluminum as the back electrode layer, patterning is performed by a photolithography method to form a back electrode layer in an opening without an insulating film. Subsequently, tris (8-quinolinolato) aluminum (hereinafter abbreviated as Alq3) was formed as an electron transport layer by a vacuum deposition method, and then dicyanomethylenepyrine, quinacridone, and 4,4'-bis (2) were formed on Alq3 as a light emitting layer. , 2-Diphenylvinyl) Form a white light emitting layer doped with biphenyl. Next, N, N'-diphenyl-N, N'-bis (α-naphthyl) -1,1'-biphenyl-4,4'-diamine is formed as a hole transport layer by a vacuum vapor deposition method. Finally, ITO (Indium Tin Oxide) is formed as a transparent electrode by sputtering to produce an OLED having a blue light emitting layer. A display can be manufactured by adhering the OLED thus obtained to face the above-mentioned wavelength conversion substrate with a sealing agent.

The wavelength conversion substrate itself of the present invention may have an OLED or an LED. In this case, a display can be manufactured by forming a partition wall on an OLED or a substrate having an LED, then forming a wavelength conversion layer, and then forming a light-shielding layer on the partition wall and the wavelength conversion layer.

It is also preferable that the wavelength conversion substrate of the present invention further has a flattening layer between the partition wall and the light-shielding layer. In particular, when the wavelength conversion substrate itself of the present invention has an OLED or LED, a partition wall is formed on the substrate having the OLED or LED, a wavelength conversion layer is formed, a flat layer is formed, and then a light-shielding layer is formed on the flat layer. Is preferable because the light-shielding layer is uniformly formed and the contrast of the display is improved.

In the present invention, the porosity of the wavelength conversion layer is preferably 0.01 to 10%. In order to obtain a wavelength conversion layer having a low porosity of less than 0.01%, it is generally necessary to increase the amount of the resin component, and the content of the wavelength conversion material may be relatively small. On the other hand, if it is larger than 10%, light scattering in the wavelength conversion layer becomes excessive, it becomes difficult to extract light, and the brightness may decrease. Further, in particular, when the wavelength conversion substrate itself of the present invention has an OLED or an LED, when the light-shielding layer is formed on the wavelength conversion layer, the light-shielding layer permeates into the voids of the wavelength conversion layer, and light absorption may be strengthened. be.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these ranges.

(Measuring method of average particle size of light scattering particles)
Light-scattering particles were placed in a water-filled sample chamber of a particle size distribution measuring device (MT3300; manufactured by Nikkiso Co., Ltd.), ultrasonically treated for 300 seconds, and then the particle size distribution was measured. The particle size to be% was defined as the average particle size.

(Raw material for wavelength conversion paste and light scattering paste)
The raw materials used to prepare the wavelength conversion paste are as follows.
Light-scattering particles: AA-1.5 (alumina, average particle size 1.6 μm, alumina, manufactured by Sumitomo Chemical Co., Ltd.)
Wavelength conversion material 1: Lumidot 640 CdSe (red quantum dot material, manufactured by Sigma-Aldrich)
Wavelength conversion material 2: Lumidot 530 CdSe (green quantum dot material, manufactured by Sigma-Aldrich)
Photopolymerization Initiator: "Irgacure" (registered trademark) OXE01 (manufactured by BASF Japan Ltd.)
Monomer: NK-9PG (polypropylene glycol # 400 dimethacrylate, which is a bifunctional methacrylate) (manufactured by Shin Nakamura Chemical Industry Co., Ltd.)
Polymer: "Etocell" (registered trademark) STD7 (I) (cellulose ethyl ether) (manufactured by DDP Specialty Products Japan Co., Ltd.)
Solvent: Propylene glycol monomethyl ether acetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.)
(Preparation of wavelength conversion paste and light scattering paste)
Weighed 25 parts by weight of light-scattering particles, 5 parts by weight of wavelength conversion material 1, 0.1 parts by weight of photopolymerization initiator, 34.9 parts by weight of monomer, 15 parts by weight of polymer, and 20 parts by weight of solvent. Then, after kneading with a three-roller kneader, the mixture was filtered through an SHP-400 filter (manufactured by Loki Techno Co., Ltd.) while applying a pressure of 100 to 400 kPa with air to obtain a wavelength conversion paste for red subpixels. Further, a wavelength conversion paste for green subpixels was obtained in the same manner except that the wavelength conversion material 1 was replaced with the wavelength conversion material 2. Further, a light scattering paste for blue subpixels was obtained in the same manner except that the wavelength conversion material 1 was not added.

(Synthesis of acrylic polymer (P-1))
After synthesizing a methyl methacrylate / methacrylic acid / styrene copolymer (mass ratio 30/40/30) by the method described in the literature (Patent No. 312476; Example 1), 40 parts by weight of glycidyl methacrylate is added and purified. By reprecipitation with water, filtration, and drying, an acrylic polymer (P-1) powder having an average molecular weight (Mw) of 40,000 and an acid value of 110 (mgKOH / g) was obtained.

(Adjustment of black pigment dispersion)
200 g of titanium nitride particles (manufactured by Nisshin Engineering Co., Ltd.) as a black pigment, 114 g of a 35 wt% solution of propylene glycol monomethyl ether acetate (hereinafter, PGMEA) of an acrylic polymer (P-1), and a third grade as a polymer dispersant. 25 g of Disperbic LPN-21116 having an amino group and a quaternary ammonium salt and 661 g of PGMEA were charged into a tank, and the mixture was stirred with a homomixer for 20 minutes to obtain a preliminary dispersion. After that, a pre-dispersion solution was supplied to an Ultra Apex Mill (manufactured by Kotobuki Kogyo) equipped with a centrifuge separator filled with 75% of 0.05 mmφ zirconia beads, and the mixture was dispersed at a rotation speed of 8 m / s for 3 hours to achieve a solid content concentration of 25. A black pigment dispersion having a mass% and a colorant / resin (mass ratio) = 80/20 was obtained.

(Adjustment of resin composition for light-shielding layer)
To 33.31 g of PGMEA, 0.35 g of ADEKA ARKULS (registered trademark) NCI-831 was added as a photopolymerization initiator, and the mixture was stirred until the solid content was dissolved. Furthermore, 5.55 g of PGMEA35 wt% solution of acrylic polymer (P-1), 2.81 g of dipentaerythritol hexaacrylate (manufactured by Nippon Kayaku Co., Ltd.) as a polyfunctional monomer, and KBM5103 (Shinetsu) manufactured as an adhesion improver. 0.60 g (manufactured by Chemical Co., Ltd.) and 0.40 g of a 10% by weight solution of silicone-based surfactant BYK333 as a surfactant were added, and the mixture was stirred at room temperature for 1 hour to obtain a photosensitive resist. By adding 56.98 g of a black pigment dispersion to this photosensitive resist, a resin composition for a light-shielding layer having a total solid content concentration of 20% and a black pigment / resin (mass ratio) = 58/42 was prepared.

(Analytical method of polysiloxane solution)
The solid content concentration of the polysiloxane solution was determined by the following method. 1.5 g of the polysiloxane solution was weighed in an aluminum cup and heated at 250 ° C. for 30 minutes using a hot plate to evaporate the liquid content. The weight of the solid content remaining in the aluminum cup after heating was weighed, and the solid content concentration of the polysiloxane solution was determined from the ratio to the weight before heating.

The weight average molecular weight of polysiloxane was determined by the following method. Using a GPC analyzer (HLC-8220; manufactured by Toso Co., Ltd.) and tetrahydrofuran as a fluidized bed, GPC analysis was performed based on JIS K 7252-3 (established on March 20, 2008), and the polystyrene-equivalent weight average was obtained. The molecular weight was measured.

The content ratio of each repeating unit in the polysiloxane was determined by the following method. A polysiloxane solution is injected into an NMR sample tube manufactured by "Teflon" (registered trademark) with a diameter of 10 mm, and ²⁹ Si-NMR measurement is performed. The content ratio of each repeating unit was calculated from the ratio of the integrated values of. ²⁹ Si-NMR measurement conditions are shown below.
Device: Nuclear magnetic resonance device (JNM-GX270, manufactured by JEOL Ltd.)
Measurement method: Gated decoupling method Measurement nuclear frequency: 53.6693 MHz ( ²⁹ Si nucleus)
Spectral width: 20,000 Hz
Pulse width: 12 μs (45 ° pulse)
Pulse repetition time: 30.0 seconds Solvent: Acetone-d6
Reference substance: Tetramethylsilane Measurement temperature: 23 ° C
Sample rotation speed: 0.0Hz
(Synthesis of polysiloxane solution)
147.32 g (0.675 mol) of trifluoropropyltrimethoxysilane, 40.66 g (0.175 mol) of 3-methacryloxypropylmethyldimethoxysilane, 3-trimethoxysilylpropylsuccinic acid in a 1,000 mL three-mouth flask. 26.23 g (0.10 mol) of anhydride, 12.32 g (0.05 mol) of 3- (3,4-epoxycyclohexyl) propyltrimethoxysilane, 0.808 g of dibutylhydroxytoluene, and 171.62 g of PGMEA. A phosphoric acid aqueous solution prepared by dissolving 2.265 g of phosphoric acid (1.0% by weight based on the charged monomer) in 52.65 g of water was added over 30 minutes with stirring at room temperature. Then, the flask was immersed in an oil bath at 70 ° C. and stirred for 90 minutes, and then the temperature of the oil bath was raised to 115 ° C. over 30 minutes. One hour after the start of the temperature rise, the solution temperature (internal temperature) reached 100 ° C., and the mixture was heated and stirred for 2 hours (internal temperature was 100 to 110 ° C.) to obtain a polysiloxane solution. During the temperature rise and heating and stirring, a mixed gas of 95% by volume of nitrogen and 5% by volume of oxygen was flowed at 0.05 L / fraction. A total of 131.35 g of methanol and water, which are by-products, were distilled off during the reaction. PGMEA was added to the obtained polysiloxane solution so that the solid content concentration was 40% by weight to obtain a polysiloxane solution. The weight average molecular weight of the obtained polysiloxane was 4,000. It is also derived from trifluoropropyltrimethoxysilane, 3-methacryloxypropylmethyldimethoxysilane, 3-trimethoxysilylpropylsuccinic anhydride, and 3- (3,4-epoxycyclohexyl) propyltrimethoxysilane in polysiloxane. The molar ratio of the repeating unit was 67.5 mol%, 17.5 mol%, 10 mol%, and 5 mol%, respectively.

(Adjustment of resin composition for partition wall)
5.00 g of titanium dioxide pigment (R-960, manufactured by BASF Japan Ltd.) as a white pigment is mixed with 5.00 g of a polysiloxane solution as a resin, and dispersed using a mill-type disperser filled with zirconia beads. Then, a pigment dispersion was obtained. Next, 9.98 g of the pigment dispersion, 0.71 g of the diacetone alcohol, 1.57 g of the polysiloxane solution, and as a photopolymerization initiator, etanone, 1- [9-ethyl-6- (2-methylbenzoyl) -9H- Carbazole-3-yl]-, 1- (О-acetyloxime) (manufactured by BASF Japan Co., Ltd.) 0.050 g, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide (BASF Japan Co., Ltd.) (Manufactured by) 0.400 g, as a photobase generator, 2- (3-benzoylphenyl) propionic acid 1,2-diisopropyl-3- [bis (dimethylamino) methylene] guanidinium (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) 0.100 g, dipentaerythritol hexaacrylate (manufactured by Shin Nihon Yakuhin Co., Ltd.) 1.20 g as a photopolymerizable compound, photopolymerizable fluorine-containing compound ("Megafuck" (registered trademark) RS) as a liquid repellent compound -76-E, manufactured by DIC Co., Ltd. 1.00 g of 40 wt% PGMEA diluted solution, 3', 4'-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate (manufactured by Daicel Co., Ltd.) 0.100 g , Ethylene bis (oxyethylene) bis [3- (5-tert-butyl-4-hydroxy-m-tolyl) propionate] (manufactured by BASF Japan Co., Ltd.) 0.030 g, acrylic solvent ("BYK"("BYK") 0.100 g (corresponding to a concentration of 500 ppm) of PGMEA 10 wt% diluted solution (registered trademark) 352, manufactured by Big Chemie Japan Co., Ltd. was dissolved in 4.76 g of the solvent PGMEA and stirred. Then, filtration was performed with a 5.0 μm filter to obtain a resin composition for a partition wall.

(Formation of light-shielding layer)
A resin composition for a light-shielding layer is applied on a 10 cm square non-alkali glass substrate (manufactured by AGC Technoglass Co., Ltd., thickness 0.7 mm) with a spin coater so that the film thickness after curing is 1.5 μm. , 90 ° C. for 10 minutes. A mask aligner PEM-6M (manufactured by Union Optical Co., Ltd.) is used for this coating film, and ultraviolet rays are emitted to 100 mJ through a photomask corresponding to the light-shielding layer shapes of Examples 1 to 5 and Comparative Examples 1 to 3 described later. Exposure was performed with an exposure amount of / cm ^2. Next, a patterned substrate was obtained by developing with an alkaline developer of a 0.5% by mass aqueous solution of tetramethylammonium hydroxide and then washing with pure water. The obtained patterning substrate is held in a hot air oven at 230 ° C. for 30 minutes and cured to have a repeating structure in the shape of the light-shielding layer shape schematic diagram (FIGS. 2, 9, or 14) described in Examples or Comparative Examples. The light-shielding layer having the unit cell of (indicated by a square dotted line in the figure) formed a light-shielding layer in which a pattern was formed in a range of 7 cm square.

(Evaluation method of light-shielding layer shape and opening shape)
The prepared substrate with a partition wall was photographed with an optical microscope image from the top surface with a laser microscope (color 3D laser microscope VK-9710, manufactured by KEYENCE CORPORATION) in camera mode, and the locations of each parameter in FIGS. 2, 9 and 14 were observed. , Measured with the attached software.

(Manufacturing of substrate with partition wall)
The resin composition for partition walls was spin-coated on the substrate on which the light-shielding layer was formed, and dried using a hot plate (SCW-636, manufactured by SCREEN Semiconductor Solutions Co., Ltd.) at a temperature of 90 ° C. for 2 minutes. A dry film was prepared. The prepared dry film was formed into a partition shape of Examples 1 to 5 and Comparative Examples 1 to 3 described later by using a parallel light mask aligner (PLA-501F, manufactured by Canon Inc.) and using an ultrahigh pressure mercury lamp as a light source. The corresponding photomasks were aligned with respect to the position of the light-shielding layer and then exposed at an exposure of 200 mJ / cm ² (i-line). Then, using an automatic developing apparatus (AD-2000, manufactured by Takizawa Sangyo Co., Ltd.), shower development was performed with a 0.045 wt% potassium hydroxide aqueous solution for 100 seconds, and then rinsing was performed with water for 30 seconds. Further, using an oven (IHPS-222, manufactured by ESPEC CORP.), It is heated in air at a temperature of 230 ° C. for 30 minutes, and has a thickness of 22 μm on a glass substrate. A partition wall having a repeating structure unit cell (shown by a square dotted line in the figure) in the shape of the schematic view (FIGS. 3, 8, 10 to 13) corresponds to the light-shielding layer shape schematic view (FIGS. 2, 9, or 14). ), A substrate with a partition wall in which a pattern was formed in an area of 7 cm square was produced.

(Evaluation method of partition wall shape and opening shape)
An optical microscope image of the prepared substrate with a partition wall was taken from the top surface with a laser microscope (color 3D laser microscope VK-9710, manufactured by KEYENCE CORPORATION) in camera mode, and the parameters of each parameter in FIGS. 3, 8, 10 to 13 were taken. The location was measured with the attached software.

(Brightness evaluation method)
A wavelength conversion paste and a light scattering paste were applied and cured to the substrates with partition walls of Examples 1 to 5 and Comparative Examples 1 and 2 by the following method to prepare a wavelength conversion substrate.

As the coating head, one having 51 discharge ports having a discharge port diameter of 50 μm and a discharge port length of 130 μm arranged at a pitch of 300 μm in the longitudinal direction of the coating head was used. As a coating device, a multi-lab coater (manufactured by Toray Engineering Co., Ltd.) was used to align the position so that the discharge port at the left end of the nozzle comes to the stripe portion of about 2.75 cm from the left end of the partition pattern, and further. After aligning the direction parallel to the stripe and the traveling direction of the nozzle, a pressure of 500 to 1,500 kPa is applied to the coating head by air, and the traveling speed with respect to the substrate is changed within the range of 20 to 200 mm / s to change the blue sub. The light scattering paste for blue subpixels was filled by applying a nozzle to the substrate with a partition while discharging the light scattering paste for pixels. Then, it was dried on a hot plate at 100 ° C. for 10 minutes, and further exposed to an exposure amount of 200 mJ / cm ² (i-line) with an ultra-high pressure mercury lamp in a nitrogen atmosphere to cure. Next, the paste in the coating head is replaced with the wavelength conversion paste for green subpixels, aligned with the partition substrate at the same position as above, and then the coating head position is shifted by +100 μm in the direction orthogonal to the stripe of the partition wall and coated in the same manner. It was dried, exposed and cured. Furthermore, the paste in the coating head is replaced with the wavelength conversion paste for red subpixels, aligned with the substrate with partition at the same position as when the light scattering paste for blue subpixels was applied, and then +200 μm in the direction orthogonal to the stripes of the partition. By shifting the position of the coating head and applying in the same manner, drying, exposing and curing, a wavelength conversion substrate in which subpixels of three colors of blue, green and red were painted separately was produced. At this time, the thickness of each wavelength conversion layer is 20 μm at the center of the unit cell for the partition-walled substrate having the shapes shown in FIGS. 3, 8, 10 to 12, and the partition wall-shaped substrate having the shape shown in FIG. The pressure and the traveling speed at the time of coating were adjusted so as to be 20 μm at the central portion of the opening of the partition wall in the orthogonal direction.

A wavelength conversion paste and a light scattering paste were applied and cured to the substrate with a partition wall of Comparative Example 3 by the following method to prepare a wavelength conversion substrate.

Dispenser (ML) to which a stage (SHOT mini (registered trademark) 200SX-SS, manufactured by Musashi Engineering Co., Ltd.) is connected as a coating device, and a nozzle (SHN-0.2N, manufactured by Musashi Engineering Co., Ltd.) is connected as a discharge device. -5000XII, manufactured by Musashi Engineering Co., Ltd. was used. In the vicinity of the center of the pattern of the substrate with a partition wall, a light scattering paste for blue subpixels was applied to a portion of the opening of the partition wall where the light-shielding layer also had an opening by dropping the light scattering paste for blue subpixels through a nozzle. Further, from the applied place, the same applies to a total of four places, -300 μm and +300 μm in the direction orthogonal to the partition wall stripe, and -300 μm and +300 μm in the direction parallel to the partition wall stripe. A light scattering paste for blue subpixels was applied. Then, it was dried on a hot plate at 100 ° C. for 10 minutes, and further exposed to an exposure amount of 200 mJ / cm ² (i-line) with an ultra-high pressure mercury lamp in a nitrogen atmosphere to cure. Next, the paste of the dispenser is replaced with the wavelength conversion paste for green subpixels, and after aligning with the substrate with the partition wall at the above-mentioned first applied portion, the portion of +100 μm in the direction orthogonal to the stripe of the partition partition, and from that portion, Apply in the same way to a total of 4 locations, -300 μm and +300 μm in the direction orthogonal to the partition stripes, and -300 μm and +300 μm in the direction parallel to the partition stripes, and dry and expose. It was cured. Furthermore, the paste of the dispenser is replaced with the wavelength conversion paste for red subpixels, and after aligning with the substrate with the partition wall at the first applied portion, the partition wall is formed at +200 μm in the direction orthogonal to the stripe of the partition partition and from that location. Apply in the same way to a total of 4 locations, -300 μm and +300 μm in the direction orthogonal to the stripes, and -300 μm and +300 μm in the direction parallel to the partition partition stripes, and dry, expose and cure. By doing so, a wavelength conversion substrate in which subpixels of three colors of blue, green, and red were painted in a range of 5 pixels was produced. At this time, the discharge amount was adjusted so that the thickness of each wavelength conversion layer was 20 μm at the center of the unit cell.

The center of one unit cell in which the light scattering layer for blue subpixels near the center of the wavelength conversion substrates of Examples 1 to 3 and Comparative Examples 1 to 3 produced by the above method is formed (for Comparative Example 3). The place where the light scattering paste for blue subpixels was first applied) was irradiated with blue light. As the blue light source, a blue backlight for LCD taken out by disassembling a commercially available liquid crystal monitor (SW2700PT, manufactured by BenQ) was used. Further, in order to irradiate light only at the center of the unit cell, a photomask having one circular opening with a diameter of 30 μm formed is placed on the blue light source, and a light-shielding layer is also opened at the opening of the partition wall on the photomask. The wavelength conversion substrate was arranged so that the surface on which the partition wall was formed was on the photomask side so that the center of the portion having the above was overlapped with the center of the hole of the photomask. While irradiating with blue light, the two-dimensional spectral radiance was measured from the substrate surface side on which the partition wall was not formed using a two-dimensional spectral radiance meter (SR-5000M, manufactured by Topcon Techno House Co., Ltd.). At this time, the brightness evaluation standard is A when the relative value of the brightness is 95 or more and A when the relative value of the brightness is 95 or more and less than 95 when the blue light brightness at the center of the unit cell on the hole of the photomask of Example 1 is set to 100. Was B, and less than that was C.

(Evaluation method of vertical light diffusion)
Regarding the wavelength conversion substrate manufactured for the evaluation of the luminance, the light from the blue light source is passed through the photomask of the partition wall on which the light scattering layer for the blue subpixel near the center of the substrate is formed, as in the case of the evaluation of the luminance. In the opening, the light-shielding layer was also irradiated to the center of the portion having the opening, and the two-dimensional spectral radiance was measured using SR-5000M. Light diffusion in the longitudinal direction, i.e., in the direction parallel to the stripes, was evaluated. At this time, when the brightness of the blue light at the center of the opening of the light-shielding layer on the hole of the photomask is set to 100, the brightness of the opening of the light-shielding layer on the lower side in the direction parallel to the stripe is measured to diffuse the light in the vertical direction. The evaluation criteria were A when no light emission was observed below the lower limit of detection, C when the relative value of brightness was less than 1, and E when it was 1 or more. In the case of E, since the center of the sub-pixels adjacent in the direction parallel to the stripe emits light with a certain brightness or more, the light diffusion is large and unsuitable.

(Evaluation method of color mixing)
Regarding the wavelength conversion substrate prepared for the evaluation of the brightness, the light from the blue light source is irradiated to the center of the unit cell in which the wavelength conversion layer for the green subpixel is formed through the photomask, as in the case of the evaluation of the brightness. Then, the two-dimensional spectral radiance was measured using SR-5000M. At this time, the relative value of the red light brightness in the adjacent red subpixel wavelength conversion layer was measured when the green light brightness at the center of the unit cell on the hole of the photomask was set to 100. The evaluation criteria for color mixing were A when the red light brightness was not observed below the detection limit, C when the red light brightness was less than 1, and D when the red light brightness was 1 or more.

(Evaluation method for riding on the top of the horizontal bulkhead)
With respect to the wavelength conversion substrate produced by the above method, whether or not the wavelength conversion layer was present on the transverse partition wall, and if so, the thickness thereof was observed with a laser microscope. A when the wavelength conversion layer is not seen on the transverse partition, B when the wavelength conversion layer is seen on the transverse partition but the thickness is less than 1 μm, C when the thickness is 1 μm or more and less than 3 μm, the thickness is The case of 3 μm or more and less than 10 μm was designated as D, and the case of 10 μm or more was designated as E. In the case of E, it is unsuitable because a wide gap is formed when the wavelength conversion substrate is bonded to the OLED substrate or the LED substrate.

(Evaluation results)
The evaluation results are shown in Table 1. All of Examples 1 to 5 were good. Comparative Example 1 in which the aperture ratio of the light-shielding layer was large and the light-shielding layer also had an opening in the opening of the partition wall was unsuitable because of low brightness. In Comparative Example 2 in which the width of the transverse partition wall was large, the ride on the top of the transverse partition wall was remarkable, and the flow direction and the degree of flow were random, so that the film thickness unevenness at the center of the partition wall opening was extremely large, and other evaluations could not be performed. ..

Comparative Example 3 in which the light-shielding layer does not have an opening in the opening of the partition wall and does not have a wavelength conversion layer is unsuitable because the vertical light diffusion is remarkable.

1 Partition 2 Opening 3 Substrate 4 Coating head 5 Paste 6 Pressurized piping 7 Discharge port 8 Light-shielding layer 9 Wavelength conversion layer

According to the present invention, it is possible to provide a wavelength conversion substrate capable of easily forming a wavelength conversion layer and further suppressing light diffusion to adjacent subpixels, which can be usefully used for a wavelength conversion type display.

Claims

A method for manufacturing a wavelength conversion substrate having a substrate, a light-shielding layer, a partition wall, and a wavelength conversion layer, wherein the opening of the partition wall has a stripe shape, and in one stripe of the stripe shape, the light-shielding layer is in the stripe direction. It has a structure in which an opening and a light-shielding portion are repeated, and the aperture ratio of the light-shielding layer in the one stripe is 5 to 70%, and further, in the one stripe, the opening of the light-shielding layer and the light-shielding portion of the light-shielding layer. A method for manufacturing a wavelength conversion substrate, each of which comprises a step of nozzle-coating a wavelength conversion paste so as to have the wavelength conversion layer having the same composition.
A method for manufacturing a wavelength conversion substrate having a substrate, a light-shielding layer, a partition wall, and a wavelength conversion layer, wherein the opening of the partition wall has a striped shape, and in one stripe of the stripe shape, the opening of the partition wall is the stripe. It has a structure in which at least two or more patterns are repeated in a direction, at least one of the repeating patterns has an opening in the light-shielding layer at the opening of the partition wall, and at least one of the repeating patterns has an opening. The light-shielding layer has substantially no opening in the opening of the partition wall, and the light-shielding layer has an opening in the opening of the partition wall and the light-shielding layer has an opening in the opening of the partition wall. A method for manufacturing a wavelength conversion substrate, which comprises a step of applying a wavelength conversion paste to the opening of the wavelength conversion substrate so as to have the wavelength conversion layer having the same composition in any of the portions having the same composition.
The method for manufacturing a wavelength conversion substrate according to claim 1 or 2, wherein the aperture ratio of the partition wall is 50 to 95% in the at least one stripe.
The wavelength conversion substrate according to any one of claims 1 to 3, wherein the thickness H of the partition wall, the thickness T 1 of the light-shielding layer, and the thickness T 2 of the wavelength conversion layer satisfy the following equations (1) and (2). Manufacturing method.
H / 100 ≤ T 1 ≤ H / 3 (1)
H / 2 ≤ T 2 ≤ H (2)
The method for manufacturing a wavelength conversion substrate according to any one of claims 1 to 4, further comprising a flattening layer between the partition wall and the light-shielding layer.
The method for manufacturing a wavelength conversion substrate according to any one of claims 1 to 5, wherein the wavelength conversion layer contains a resin.
The method for manufacturing a wavelength conversion substrate according to any one of claims 1 to 6, wherein the wavelength conversion layer has a porosity of 0.01 to 10%.
The method for manufacturing a wavelength conversion substrate according to any one of claims 1 to 7, wherein the light-shielding layer has a reflectance of 0.1 to 10%.
The method for manufacturing a wavelength conversion substrate according to any one of claims 1 to 8, wherein the wavelength conversion layer contains an inorganic phosphor.
The method for manufacturing a wavelength conversion substrate according to any one of claims 1 to 8, wherein the wavelength conversion layer contains quantum dots.
A wavelength conversion substrate having a substrate, a light-shielding layer, a partition wall, and a wavelength conversion layer, the opening of the partition wall having a stripe shape, and in one stripe of the stripe shape, the light-shielding layer has an opening in the stripe direction. The light-shielding layer has an aperture ratio of 5 to 70% in the one stripe, and either the opening of the light-shielding layer or the light-shielding portion of the light-shielding layer in the one stripe. Also, a wavelength conversion substrate having the wavelength conversion layer having the same composition.
A wavelength conversion substrate having a substrate, a light-shielding layer, a partition wall, and a wavelength conversion layer, in which the opening of the partition wall is striped, and in one stripe of the stripe shape, the opening of the partition wall is in the stripe direction. It has a structure in which at least two or more patterns are repeated, at least one of the repeating patterns also has an opening in the light-shielding layer at the opening of the partition, and at least one of the repeating patterns has the partition. The light-shielding layer has substantially no opening in the opening of the partition wall, and further, the light-shielding layer has an opening in the opening of the partition wall and the light-shielding layer has an opening in the opening of the partition wall. A wavelength conversion substrate having the wavelength conversion layer having the same composition in any of the places where the wavelength is not formed.
A display having the wavelength conversion substrate according to claim 11 or 12 and an OLED or LED as a light source.