TW202129999A - Wavelength conversion member, backlight unit and image display device - Google Patents

Abstract

A wavelength conversion member includes a wavelength conversion layer containing a phosphor, and the wavelength conversion member has a storage modulus of 4.1 GPa or less as measured by a dynamic mechanical analyzer at a frequency of 10Hz and a temperature of 30°C.

Description

Wavelength conversion member, backlight unit and image display device

The present disclosure relates to a wavelength conversion member, a backlight unit, and an image display device.

In recent years, in the field of image display devices such as liquid crystal display devices, it is required to improve the color reproducibility of displays as a means to improve color reproducibility, such as Japanese Patent Publication No. 2013-544018 and International Publication No. 2016/052625 As described in the number, wavelength conversion members containing quantum dot phosphors are attracting attention.

The wavelength conversion member including the phosphor is arranged in, for example, a backlight unit of an image display device. In the case of using a wavelength conversion member including a quantum dot phosphor that emits red light and a quantum dot phosphor that emits green light, if the wavelength conversion member is irradiated with blue light as the excitation light, the quantum dot The red light and green light emitted by the phosphor and the blue light transmitted through the wavelength conversion member obtain white light. With the development of a wavelength conversion component containing quantum dot phosphors, the color reproducibility of the display has been expanded from the previous 72% NTSC ((National Television System Committee) (National Television System Committee) ratio of the United States) to 100% NTSC ratio .

The wavelength conversion member containing a phosphor usually has a cured product obtained by curing a curable composition containing a phosphor. As the curable composition, there are a thermosetting type and a photocuring type. From the viewpoint of productivity, it is preferable to use a photocuring type curable composition.

In addition, in the wavelength conversion member including the phosphor, at least a part of the cured product including the phosphor may be covered with a coating material. For example, in the case of a film-like wavelength conversion member, a barrier film having oxygen barrier properties may be provided on one or both sides of a cured product containing a phosphor.

[The problem to be solved by the invention]

Conventionally, a film-shaped wavelength conversion member containing a phosphor is cut out and formed into a single sheet for transportation or storage. On the other hand, from the viewpoint of improving the efficiency of transportation or storage, it is desirable that the wavelength conversion member is rolled into a roll shape, that is, it is formed into a roll.

The wavelength conversion member formed into a roll is unfolded into a flat shape for use in subsequent press processing or the like. However, the wavelength conversion member formed as a roll is curled during storage, and it is difficult to restore it to a flat shape by its own weight. In addition, if the unwinding of the wavelength conversion member is insufficient, when it is used in a backlight of an image display device, there is a possibility that influences such as blurring of light passing through the wavelength conversion member may occur. Here, it was discovered by the inventors of the present invention that although the wavelength conversion member can be restored to a planar shape by standing still at a high temperature of, for example, about 85°C, if the wavelength conversion member is supplied to a high temperature, the quantum dot fluorescent The optical properties of the optical body are degraded. Therefore, it is desirable to be able to efficiently unwind the wavelength conversion member into a flat shape at a relatively low temperature (for example, 45° C. or lower) without being supplied to a high temperature.

In view of the above circumstances, an object of the present disclosure is to provide a wavelength conversion member that is easily unrolled after being formed into a roll, and a backlight unit and an image display device using the wavelength conversion member. [Means to solve the problem]

The means for solving the above-mentioned problems include the following aspects. <1> A wavelength conversion member having a wavelength conversion layer containing a phosphor, and when measured with a dynamic viscoelasticity measuring device at a frequency of 10 Hz and a temperature of 30°C, the storage elastic coefficient of the wavelength conversion member Below 4.1 GPa. <2> The wavelength conversion member according to <1>, wherein the value measured by the following method is 6.0 mm or more: On a test bench, the wavelength conversion member processed into a rectangle with a width of 20 mm is selected from the The test stand was arranged to protrude 10 cm to the outside, and the distance between the height of the tip portion of the wavelength conversion member that sags due to its own weight and the height of the reference surface of the test stand was measured. <3> The wavelength conversion member according to <1> or <2>, wherein the phosphor includes a quantum dot phosphor. <4> The wavelength conversion member according to <3>, wherein the quantum dot phosphor contains at least one of Cd and In. <5> The wavelength conversion member according to any one of <1> to <4>, wherein the wavelength conversion layer includes a cured product of a resin composition containing: the phosphor; sulfur Alcohol compound; at least one selected from the group consisting of (meth)acrylic compound and (meth)allyl compound; and photopolymerization initiator. <6> The wavelength conversion member according to any one of <1> to <5>, which is formed in a roll shape. <7> A backlight unit including the wavelength conversion member and light source according to any one of <1> to <5>. <8> An image display device including the backlight unit as described in <7>. [Effects of the invention]

According to the present disclosure, there are provided a wavelength conversion member that is easy to unwind after being formed into a roll, and a backlight unit and an image display device using the wavelength conversion member.

Hereinafter, an embodiment of the present disclosure will be described in detail. However, the embodiment of this disclosure is not limited to the following embodiment. In the following embodiments, the constituent elements (including element steps, etc.) are not essential unless otherwise specified. The same is true for the numerical value and its range, and does not limit the embodiment of the present disclosure.

In this disclosure, the numerical values described before and after the "～" included in the numerical range indicated by "~" are used as the minimum and maximum values, respectively. In the numerical ranges described stepwise in this disclosure, the upper limit or lower limit described in one numerical range may be replaced with the upper limit or lower limit of other numerical ranges described stepwise. In addition, in the numerical range described in the present disclosure, the upper limit or lower limit of the numerical range may be replaced with the values shown in the examples. In the present disclosure, each component may also include a plurality of corresponding substances. When there are multiple types of substances corresponding to each component in the composition, unless otherwise specified, the content rate or content of each component refers to the total content rate or content of the multiple types of substances present in the composition. In the present disclosure, a plurality of particles consistent with each component can also be included. When there are a plurality of types of particles corresponding to each component in the composition, unless otherwise specified, the particle size of each component refers to a value with respect to a mixture of the plurality of types of particles present in the composition. In the present disclosure, the term "layer" or "film" includes not only the case formed in the entire area when the layer or film is observed, but also the case formed only in a part of the area. In the present disclosure, the term "layered" means to superimpose layers, so that two or more layers can be combined, or two or more layers can be assembled and disassembled. In this disclosure, the so-called "(meth)acrylate" refers to at least one of acrylate and methacrylate, and the so-called "(meth)allyl" refers to the combination of allyl and methallyl At least one, "(meth)acrylic acid" means at least one of acrylic acid and methacrylic acid, and "(meth)acrylic acid group" means at least one of acrylic acid group and methacrylic acid group. In this disclosure, when the embodiment is described with reference to the drawings, the configuration of the embodiment is not limited to the configuration shown in the drawings. In addition, the size of the components in each figure is conceptual, and the relative size of the components is not limited to this. In addition, in each of the drawings, members having substantially the same function are given the same reference numerals in all the drawings, and repeated descriptions are sometimes omitted.

"Wavelength Conversion Components" The wavelength conversion member of the present disclosure has a wavelength conversion layer including a phosphor, and has a storage elastic coefficient of 4.1 GPa or less when measured with a dynamic viscoelasticity measuring device under the conditions of a frequency of 10 Hz and a temperature of 30°C.

According to the wavelength conversion member of the present disclosure, it is possible to efficiently perform unwinding after being formed into a roll. The reason is not necessarily clear, but it is considered that since the wavelength conversion member of the present disclosure has the storage elastic coefficient, curling (warpage) is easy to recover, even if the solution is performed at a relatively low temperature (for example, 45°C or less). It can also be unrolled efficiently.

The unwinding of the wavelength conversion member formed as a roll is performed by the following method, for example. The wavelength conversion member formed into a roll is unrolled, and after press processing, the wavelength conversion member stacked in a single sheet shape is clamped in a glass plate, etc., and placed in a constant temperature bath under the condition of 60°C or less set time. For example, when 50 wavelength conversion members that are stamped into a rectangle of 1470 mm × 850 mm are stacked and clamped in a glass plate, and left standing at 45°C for 24 hours, the amount of curl (warpage) is relatively high. It is preferably within 8.0 mm, more preferably within 5.0 mm, and still more preferably within 3.0 mm. The amount of curl (amount of warpage) was set to the maximum value when measured at 6 points at the arbitrary end of the wavelength conversion member after press processing.

The wavelength conversion member may be formed in a roll shape. The wavelength conversion member of the present disclosure is suitable for being formed as a roll. By forming the wavelength conversion member into a roll, transportation efficiency and storage efficiency can be improved. Furthermore, compared with the case where the wavelength conversion member is processed into a single piece for transportation or storage, the end portion of the wavelength conversion member can be reduced, and therefore, the deterioration of the end portion can be suppressed.

The storage elastic coefficient of the wavelength conversion member measured under the conditions of a frequency of 10 Hz and a temperature of 30°C is 4.1 GPa or less, and from the viewpoint of ease of unwinding after being formed into a roll, it is preferably 3.9 GPa or less, and more preferably It is 3.7 GPa or less, more preferably 3.6 GPa or less, particularly preferably 3.0 GPa or less, and extremely preferably 2.5 GPa or less. From the viewpoint of handling properties, the storage elastic coefficient is preferably 1.0 GPa or more, more preferably 1.5 GPa or more, and still more preferably 1.8 GPa or more. The storage elastic coefficient of the wavelength conversion member can be measured using a dynamic viscoelastic measuring device (for example, Rheometric Scientific, Solid Analyzer RSA-III).

The method of adjusting the storage elastic coefficient of the wavelength conversion member is not particularly limited. For example, a method of adjusting the material, thickness, laminated structure, etc. of the wavelength conversion layer and the cladding material used as needed later may be mentioned. For example, if the thickness of the wavelength conversion member is reduced, the storage elastic coefficient tends to decrease. In addition, in the case of using a covering material, if the thickness of the covering material is reduced, the storage elastic coefficient tends to decrease. The storage elasticity coefficient can also be adjusted by setting the coating material into a multilayer structure and including an adhesive layer in the base material layer.

The shape of the wavelength conversion member is preferably a film shape. Since the wavelength conversion member is in the shape of a film, it can be preferably used in a backlight unit, and in addition, it can be preferably formed as a roll.

The width and length of the wavelength conversion member are not particularly limited. For example, they can be appropriately set according to the size of the image display device to be applied, and the like.

In the case of the wavelength conversion member formed as a roll, the width of the wavelength conversion member can be appropriately adjusted according to the application, and may be, for example, 10 mm to 5000 mm. In the case of the wavelength conversion member formed as a roll, the length of the wavelength conversion member can be appropriately adjusted according to the application, and may be, for example, 0.5 m to 1000 m. In the case of the wavelength conversion member formed as a roll, the length of the wavelength conversion member refers to the length along the winding direction, and the length orthogonal to the length is the width of the wavelength conversion member.

In the case of the wavelength conversion member after the wavelength conversion member formed as a roll is unrolled and subjected to press processing, the width of the wavelength conversion member can be appropriately adjusted according to the application, and may be, for example, 10 mm to 5000 mm. In the case of the wavelength conversion member after the wavelength conversion member formed as a roll is unrolled and subjected to press processing, the length of the wavelength conversion member can be appropriately adjusted according to the use, and may be, for example, 10 mm to 5000 mm.

In the case of the wavelength conversion member after press processing, the length of the wavelength conversion member refers to the length in the long side direction, and the width of the wavelength conversion member refers to the length in the short side direction. When the wavelength conversion member is a square, the length of one side of the square is preferably included in the range of either the width or the length of the wavelength conversion member.

The average thickness of the wavelength conversion member is, for example, preferably 100 μm to 500 μm, more preferably 120 μm to 400 μm, and still more preferably 150 μm to 300 μm. If the average thickness of the wavelength conversion member is 100 μm or more, the wavelength conversion efficiency tends to be further improved. If the average thickness of the wavelength conversion member is 500 μm or less, it may be useful when the wavelength conversion member is applied to the backlight unit. The backlight unit tends to be thinner. The average thickness of the wavelength conversion member can be obtained, for example, as an arithmetic average of the thicknesses of any three locations measured with a micrometer.

One or both surfaces of the wavelength conversion member may be roughened. The surface roughness Ra may be 0.5 μm or more, for example. If the wavelength conversion member is roughened, it is excellent in handleability, and interference fringes generated due to the close contact between the adjacent member and the wavelength conversion member can be suppressed.

The surface roughness Ra refers to a value measured using a three dimensional (3D) microscope (for example, Olympus Co., Ltd., model OLS4100, magnification 10 times). The measurement range is set to the line roughness at a length of 1289 μm. The analysis method is to set the analysis parameter as the roughness parameter, and the cut-off as λC; none, λS; none, λf; none. Here, λC, λS, and λf are calculation methods for calculating the profile curve of Ra. The profile curve includes profile curve, roughness curve and waviness curve. The profile curve is a curve obtained by applying a low-pass filter with a cut-off value of λS in the measurement profile curve. The roughness curve is a profile curve obtained by cutting off the long-wavelength component from the profile curve by a high-pass filter with a cut-off value of λC. The waviness curve is a profile curve obtained by applying a cut-off value λf and a cut-off value λC to the profile curve filter in sequence. The long-wavelength component is cut by the λf profile filter, and the short-wavelength component is cut by the λC profile filter.

From the viewpoint of further improving light utilization efficiency, the total light transmittance of the wavelength conversion member is preferably 55% or more, more preferably 60% or more, and still more preferably 65% or more. The total light transmittance of the wavelength conversion member can be measured in accordance with the measurement method of Japanese Industrial Standards (JIS) K 7361-1:1997.

In addition, from the viewpoint of further improving light utilization efficiency, the haze of the wavelength conversion member is preferably 10% to 60%, more preferably 10% to 55%, and still more preferably 10% to 50%. The haze of the wavelength conversion member can be measured in accordance with the measuring method of JIS K 7136:2000.

In the wavelength conversion member, the value measured by the following method (hereinafter may be referred to as a specific value) can also be adjusted. On a test stand with a height of 10 cm or more, the wavelength conversion member processed into a rectangle with a width of 20 mm was arranged so as to protrude 10 cm from the test stand to the outside, and the wavelength conversion drooping due to its own weight was measured. The distance between the height of the front end of the component and the height of the reference surface of the test bench. Here, the height of the reference surface refers to the height on the test bench where the processed wavelength conversion member is disposed, and the remaining part other than the protruding part. The test stand is not particularly limited in shape and size as long as it can fix the remaining part of the wavelength conversion member processed into a rectangle with a width of 20 mm except for the part protruding from the test stand. From the viewpoint of ease of unwinding after being formed into a roll, the specific value of the wavelength conversion member measured by the method is preferably 6.0 mm or more, more preferably 8.0 mm or more, and still more preferably 10.0 mm or more . From the viewpoint of handleability, the specific value of the wavelength conversion member measured by the method is preferably 35.0 mm or less, more preferably 25.0 mm or less, and still more preferably 15.0 mm or less.

The method of adjusting the specific value of the wavelength conversion member measured by the method described above is not particularly limited. For example, the material, thickness, elastic modulus, and layered structure of the wavelength conversion layer and the coating material used as needed later can be mentioned. Wait for the adjustment method. For example, by reducing the thickness of the wavelength conversion member, the specific value measured by the method tends to increase. In addition, in the case of using a covering material, by reducing the thickness of the covering material, there is a tendency that the specific value measured by the method described above becomes larger. There is also a tendency for the specific value measured by the method to become larger by making the covering material into a multilayer structure and including the adhesive layer in the base layer.

In the wavelength conversion member of the present disclosure, it is preferable to use a thermomechanical analysis (TMA) device under the conditions of a load of 0.05 N and a heating rate of 10° C./min. The coefficient of thermal expansion below the glass transition temperature is 30 ppm. /°C or higher, or the thermal expansion coefficient above the glass transition temperature is 0 ppm/°C or lower. The wavelength conversion member of the present disclosure can satisfy the two requirements at the same time. Hereinafter, the coefficient of thermal expansion when the member is measured under the conditions described above will also be referred to simply as the "coefficient of thermal expansion". The coefficient of thermal expansion below the glass transition temperature of the member is measured in a temperature range of any 20°C from the glass transition temperature of -100°C to the glass transition temperature. The coefficient of thermal expansion above the glass transition temperature of the member is measured in a temperature range of any 20°C in the range from the glass transition temperature to the glass transition temperature +100°C. Specifically, the thermal expansion coefficient of the member can be measured, for example, by the method described in the examples. Although the clear reason is not known, it is estimated that the thermal expansion coefficient below the glass transition temperature is large, or the thermal expansion coefficient above the glass transition temperature is 0 ppm/℃ or below, which means that the free volume in the resin material is large, and after the roll is formed It is easy to return to its original shape when unrolling.

When the coefficient of thermal expansion below the glass transition temperature of the wavelength conversion member is 30 ppm/°C or higher, the coefficient of thermal expansion may be 32 ppm/°C or higher, or 35 ppm/°C or higher. From the viewpoint of shape stability, the thermal expansion coefficient below the glass transition temperature of the wavelength conversion member may be 60 ppm/°C or lower, 50 ppm/°C or lower, or 45 ppm/°C or lower. When the thermal expansion coefficient above the glass transition temperature of the wavelength conversion member is 0 ppm/℃ or below, the thermal expansion coefficient may be -10 ppm/℃ or below, -20 ppm/℃ or below, or -30 ppm /℃ below. From the viewpoint of shape stability, the coefficient of thermal expansion above the glass transition temperature of the wavelength conversion member may be -60 ppm/°C or higher, may be -50 ppm/°C or higher, or may be -45 ppm/°C or higher.

When the wavelength conversion member includes a coating material, the coefficient of thermal expansion above the glass transition temperature of the coating material is preferably 0 ppm/°C or less. If the coefficient of thermal expansion of the covering material is in the above range, it is found that there is a tendency that the amount of curl when unwinding after being formed into a roll is smaller. The reason is not certain, but it is presumed that the softening of the covering material makes it easy to follow the wavelength conversion layer, and the amount of curl is suppressed. The coefficient of thermal expansion above the glass transition temperature of the coating material can be -10 ppm/℃ or less, -20 ppm/℃ or below, -50 ppm/℃ or below, or -70 ppm/℃ or below. In addition, from the viewpoint of shape stability, the coefficient of thermal expansion above the glass transition temperature of the coating material may be -100 ppm/°C or more.

In the case where the wavelength conversion member includes a coating material, if the coefficient of thermal expansion below the glass transition temperature of the coating material is subtracted from the coefficient of thermal expansion below the glass transition temperature of the wavelength conversion member (also referred to as the difference in coefficient of thermal expansion) ) Is 10 ppm/°C or more, it is found that there is a tendency that the amount of curl when unwinding after being formed into a roll is smaller. The reason is not certain, but it is presumed that a large difference in thermal expansion means that the coating material follows the wavelength conversion layer, and the amount of curl is suppressed by the coating material following the wavelength conversion layer. The difference in the thermal expansion coefficient may be 12 ppm/°C or more, or 14 ppm/°C or more. From the viewpoint of shape stability, the difference in the thermal expansion coefficient may be 120 ppm/°C or less, or 110 ppm/°C or less.

As a method of adjusting the coefficient of thermal expansion, for example, a method of adjusting the material, thickness, coefficient of elasticity, layered structure, etc. of the wavelength conversion layer and the cladding material to be used as needed later.

＜Covering material＞ The wavelength conversion member may have a covering material arranged on one side or both sides of the wavelength conversion layer.

The average thickness of the coating material is preferably 8 μm or more, may also be 15 μm or more, or may be 20 μm or more. If the average thickness of the covering material is 8 μm or more, the handleability of the wavelength conversion member is improved, and functions such as barrier properties tend to become sufficient. In addition, the average thickness of the coating material is preferably 150 μm or less, more preferably 100 μm or less, and still more preferably 80 μm or less. If the average thickness of the covering material is 150 μm or less, the decrease in light transmittance tends to be suppressed. In addition, there is a tendency that unwinding after being formed into a roll becomes easy. From the above viewpoints, the average thickness of the coating material is preferably 8 μm to 150 μm, more preferably 15 μm to 100 μm, and still more preferably 20 μm to 80 μm. The average thickness of the coating material is calculated|required as an arithmetic mean value of the thickness of arbitrary three places measured using a micrometer, for example.

The coating material can be roughened. In this case, the surface of the cladding material arranged on one side of the wavelength conversion layer that does not face the wavelength conversion layer, or the cladding material arranged on both sides of the wavelength conversion layer does not face the wavelength conversion layer At least one of the surfaces on the side may be roughened. For example, the surface roughness Ra may be 0.5 μm or more. When the wavelength conversion member has a coating material, if the coating material is roughened, the image conversion member has excellent handleability and tends to suppress interference fringes caused by the close contact between the adjacent member and the wavelength conversion member.

The material of the covering material is not particularly limited, and it can be polyester such as polyethylene terephthalate (PET), polyethylene naphthalate (PEN), etc.; polyethylene (PE), polypropylene (PP) And other polyolefins; nylon and other polyamides; ethylene-vinyl alcohol copolymer (EVOH), etc. From the viewpoint of easy availability, the material of the covering material is preferably polyethylene terephthalate. The coating material may also include a barrier layer (barrier film) to improve the barrier function. As the barrier layer, an inorganic layer containing an inorganic substance such as aluminum oxide and silicon dioxide can be cited.

From the viewpoint of suppressing the decrease in the luminous efficiency of the phosphor, the coating material preferably has barrier properties to at least one of oxygen and water, and more preferably has barrier properties to both oxygen and water. There are no particular restrictions on the coating material having barrier properties for at least one of oxygen and water, and a barrier film having an inorganic layer or the like can be used.

The oxygen permeability of the coating material is, for example, preferably 0.5 mL/(m ² ·24 h·atm) or less, more preferably 0.3 mL/(m ² ·24 h·atm) or less, and still more preferably 0.1 mL/( m ² ·24 h·atm) or less. The oxygen transmission rate of the coating material can be measured using an oxygen transmission rate measuring device (for example, MOCON company, OX-TRAN) at a temperature of 23° C. and a relative humidity of 65%.

In addition, the water vapor transmission rate of the coating material is, for example, preferably 5×10 ^-2 g/(m ² ·24 h·Pa) or less, and more preferably 1×10 ^-2 g/(m ² ·24 h·Pa) ) Or less, more preferably 5×10 ^-3 g/(m ² ·24 h·Pa) or less. The water vapor transmission rate of the coating material can be measured using a water vapor transmission rate measuring device (for example, MOCON, AQUATRAN) at a temperature of 40° C. and a relative humidity of 90%.

The covering material can be laminated in multiple layers. For example, the covering material may be laminated with a substrate layer, a barrier layer, an undercoat layer, and the like.

＜Wavelength conversion layer＞ The wavelength conversion member of the present disclosure includes a wavelength conversion layer. The wavelength conversion layer contains a phosphor. The wavelength conversion layer may further include a cured resin, and the phosphor may be contained in the cured resin. In addition, the wavelength conversion layer may further include a light diffusing material.

[Phosphor] The wavelength conversion layer includes a phosphor that emits light by being irradiated with light from a light source. The type of phosphor is not particularly limited, and examples thereof include organic phosphors and inorganic phosphors. Examples of organic phosphors include naphthalimide compounds and perylene compounds. Examples of inorganic phosphors include: Y ₃ O ₃ :Eu, YVO ₄ :Eu, Y ₂ O ₂ :Eu, 3.5MgO·0.5 MgF ₂ , GeO ₂ :Mn, (Y·Cd)BO ₂ :Eu, etc. Red light-emitting inorganic phosphor, ZnS: Cu·Al, (Zn·Cd)S: Cu·Al, ZnS: Cu·Au·Al, Zn ₂ SiO ₄ : Mn, ZnSiO ₄ : Mn, ZnS: Ag·Cu, (Zn·Cd)S: Cu, ZnS: Cu, GdOS: Tb, LaOS: Tb, YSiO ₄ : Ce·Tb, ZnGeO ₄ : Mn, GeMgAlO: Tb, SrGaS: Eu ²⁺ , ZnS: Cu·Co, MgO ·NB ₂ O ₃ :Ge·Tb, LaOBr:Tb·Tm, La ₂ O ₂ S:Tb and other green light-emitting inorganic phosphors, ZnS:Ag, GaWO ₄ , Y ₂ SiO ₆ :Ce, ZnS:Ag·Ga ·Cl, Ca ₂ B ₄ OCl:Eu ²⁺ , BaMgAl ₄ O ₃ :Eu ²⁺ and other blue-emitting inorganic phosphors, quantum dot phosphors, etc.

As the phosphor, a quantum dot phosphor is preferred from the viewpoint of excellent color reproducibility of an image display device. The quantum dot phosphor is not particularly limited, and examples thereof include particles containing at least one selected from the group consisting of group II-VI compounds, group III-V compounds, group IV-VI compounds, and group IV compounds. From the viewpoint of luminous efficiency, the quantum dot phosphor preferably contains a compound containing at least one of Cd and In.

Specific examples of II-VI group compounds include: CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, HgSeTe, HgSTe , CdZnS, CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHSegSTe, HgZnSeS, HgZnSeS, HgZnSe, etc. Specific examples of III-V compounds include: GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, GaNP, GaNAS, GaNSb, GaPAs, GaPSb, AlNP, AlNAs , AlNSb, AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInPSb, InAlNP, InAlNAs, InAlPAs, InAlNP, InAlNAs, InAlPA, InAlNP, InAlPS, etc. Specific examples of Group IV-VI compounds include SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbSe, SnPbSSe, SnPbSeTe, SnPbSeTe, SnPbSte, SnPbSte, and the like. Specific examples of group IV compounds include Si, Ge, SiC, SiGe, and the like.

As the quantum dot phosphor, it may also have a core-shell structure. By making the band gap of the compound constituting the shell wider than the band gap of the compound constituting the core, the quantum efficiency of the quantum dot phosphor can be further improved. Examples of the combination of core and shell (core/shell) include CdSe/ZnS, InP/ZnS, PbSe/PbS, CdSe/CdS, CdTe/CdS, CdTe/ZnS, and the like.

In addition, as the quantum dot phosphor, one having a so-called core multi-shell structure in which the shell is a multilayer structure may also be used. Laminating one or more layers of shells with a narrow band gap on the core with a wide band gap, and then laminating a shell with a wide band gap on the shell, can further improve the quantum efficiency of the quantum dot phosphor.

In the case where the wavelength conversion layer contains quantum dot phosphors, the wavelength conversion layer may contain one kind of quantum dot phosphors alone, or a combination of two or more kinds of quantum dot phosphors. As an aspect that contains two or more quantum dot phosphors in combination, for example, an aspect that contains two or more quantum dot phosphors with different components but the same average particle size, and an aspect that contains two or more kinds of quantum dot phosphors with the same average particle size can be cited. The aspect of quantum dot phosphors with different diameters but the same composition, and the aspect of quantum dot phosphors containing two or more kinds of components and different average particle diameters. By changing at least one of the composition and average particle diameter of the quantum dot phosphor, the emission center wavelength of the quantum dot phosphor can be changed.

For example, the wavelength conversion layer may contain a quantum dot phosphor G having a central emission wavelength in the green wavelength region of 520 nm to 560 nm, and a quantum dot phosphor having a central emission wavelength in the red wavelength region of 600 nm to 680 nm. Light body R. If the wavelength conversion layer containing the quantum dot phosphor G and the quantum dot phosphor R is irradiated with excitation light in the blue wavelength region of 430 nm to 480 nm, the excitation light is emitted from the quantum dot phosphor G and the quantum dot phosphor, respectively R emits green light and red light. As a result, white light can be obtained by the green light and red light emitted from the quantum dot phosphor G and the quantum dot phosphor R, and the blue light transmitted through the hardened object.

With respect to the entire wavelength conversion layer, the content of the phosphor in the wavelength conversion layer is, for example, preferably 0.01% by mass to 1.0% by mass, more preferably 0.05% by mass to 0.5% by mass, and still more preferably 0.1% by mass to 0.5. quality%. If the content of the phosphor is 0.01% by mass or more relative to the entire wavelength conversion layer, there is a tendency to obtain a sufficient wavelength conversion function. If the content of the phosphor is 1.0% by mass or less, there is a tendency for the phosphor to be The tendency to suppress aggregation.

[Resin Cured Material] The wavelength conversion layer may further include a resin cured product. The wavelength conversion layer may be a layer in a state where the phosphor is contained in a cured resin material.

From the viewpoints of the adhesion of the resin cured product to other members (covering materials, etc.) and the suppression of the generation of wrinkles due to volume shrinkage during curing, the resin cured product preferably contains a sulfide structure. The cured resin containing a thioether structure can be obtained by curing, for example, a resin composition containing a thiol compound described later, and carbon having an enethiol reaction with the thiol group of the thiol compound. Polymeric compound with carbon double bond.

From the viewpoints of the heat resistance and moisture and heat resistance of the wavelength conversion layer, the cured resin preferably contains an alicyclic structure or an aromatic ring structure. The cured resin having an alicyclic structure or an aromatic ring structure can be obtained by curing, for example, a resin composition containing an alicyclic structure or an aromatic ring structure as a polymerizable compound described later.

From the viewpoint of suppressing the contact between the phosphor and oxygen, the cured resin preferably contains an alkoxy group. If the cured resin contains an alkoxy group, the polarity of the cured resin increases, and non-polar oxygen tends to be difficult to dissolve in the components in the cured product. In addition, there is a tendency for the flexibility of the cured resin to increase and the adhesion to the covering material to improve.

The cured resin containing an alkoxyl group can be obtained by curing, for example, a resin composition containing an alkoxyl group as a polymerizable compound described later.

-Resin composition- The wavelength conversion layer may be a cured product of a composition containing a phosphor, a polymerizable compound, and a photopolymerization initiator (hereinafter, also simply referred to as a resin composition). The resin composition preferably contains a phosphor, a thiol compound, at least one selected from the group consisting of a (meth)acrylic compound and a (meth)allyl compound, and a photopolymerization initiator. The resin composition may optionally contain other components. Hereinafter, each component of the resin composition will be described in detail.

(Fluorescent body) The resin composition contains a phosphor. The details of the phosphor are as described above.

In the case of using a quantum dot phosphor as the phosphor, the quantum dot phosphor can also be used in the state of a quantum dot phosphor dispersion liquid that is dispersed in a dispersion medium. As the dispersion medium in which the quantum dot phosphor is dispersed, various organic solvents, silicone compounds, and monofunctional (meth)acrylate compounds can be cited. The quantum dot phosphor can be used in the state of a quantum dot phosphor dispersion liquid by using a dispersant as necessary.

As an organic solvent that can be used as a dispersion medium, if sedimentation and aggregation of the quantum dot phosphor is not confirmed, it is not particularly limited. Examples include acetonitrile, methanol, ethanol, acetone, 1-propanol, ethyl acetate, and acetic acid. Butyl ester, toluene, hexane, etc.

The silicone compound that can be used as a dispersion medium includes straight silicone oils such as dimethyl silicone oil, methyl phenyl silicone oil, methyl hydrogen silicone oil, etc.; Silicone oil, epoxy modified silicone oil, carboxy modified silicone oil, methanol modified silicone oil, mercapto modified silicone oil, heterofunctional group modified silicone oil, polyether modified silicone oil Modification of oil, methylstyrene-based modified silicone oil, hydrophilic special modified silicone oil, high-grade alkoxy modified silicone oil, high-grade fatty acid modified silicone oil, fluorine-modified silicone oil, etc. Silicone oil, etc.

The monofunctional (meth)acrylate compound that can be used as a dispersion medium is not particularly limited as long as it is liquid at room temperature (25°C), and includes monofunctional (meth)acrylic acid having an alicyclic structure Ester compounds (preferably isobornyl (meth)acrylate and dicyclopentyl (meth)acrylate), methoxy polyethylene glycol (meth) acrylate, phenoxy polyethylene glycol (methyl) ) Acrylate, ethoxylated o-phenylphenol (meth)acrylate, etc.

As a dispersing agent used as needed, polyetheramine (JEFFAMINE M-1000, Huntsman) etc. can be mentioned.

The mass-based ratio of the quantum dot phosphor in the quantum dot phosphor dispersion is preferably 1% by mass to 20% by mass, more preferably 1% by mass to 10% by mass.

In the case where the mass-based ratio of the quantum dot phosphor in the quantum dot phosphor dispersion is 1% by mass to 20% by mass, the quantum dots in the resin composition are relative to the total amount of the resin composition The content rate of the phosphor dispersion liquid is preferably, for example, 1% by mass to 10% by mass. In addition, relative to the total amount of the resin composition, the content of the quantum dot phosphor in the resin composition is, for example, preferably 0.01% by mass to 1.0% by mass, more preferably 0.05% by mass to 0.5% by mass, and still more preferably It is 0.1% by mass to 0.5% by mass. If the content of the quantum dot phosphor is 0.01% by mass or more, there is a tendency that sufficient luminous intensity can be obtained when the cured product is irradiated with excitation light. If the content of the quantum dot phosphor is 1.0% by mass or less, then There is a tendency for the aggregation of quantum dot phosphors to be suppressed.

(Polymerizable compound) The resin composition contains a polymerizable compound. The polymerizable compound contained in the resin composition is not particularly limited, and examples thereof include thiol compounds, (meth)acrylic compounds, and (meth)allyl compounds. In addition, a (meth)allyl compound refers to a compound having a (meth)allyl group in the molecule, and a (meth)acrylic compound refers to a compound having a (meth)acryloyl group in the molecule. For convenience, compounds having both (meth)allyl and (meth)acrylic groups in the molecule are classified as (meth)allyl compounds.

From the viewpoint of the adhesiveness of the wavelength conversion layer with respect to other members (covering materials, etc.), the resin composition preferably contains a thiol compound and a compound selected from the group consisting of (meth)acrylic compounds and (meth)allyl groups. At least one of the group consisting of compounds is used as a polymerizable compound.

The cured product obtained by curing a resin composition containing a thiol compound and at least one selected from the group consisting of a (meth)acrylic compound and a (meth)allyl compound as a polymerizable compound contains The thioether structure formed by the enthiol reaction between the thiol group and the carbon-carbon double bond of the (meth)acryloyl group or (meth)allyl group (RS-R', R and R'represent organic base). This tends to improve the adhesion between the wavelength conversion layer and the coating material. In addition, the optical properties of the wavelength conversion layer tend to be further improved. Hereinafter, the thiol compound, the (meth)acrylic compound, and the (meth)allyl compound will be described in detail.

A. Thiol compounds The thiol compound may be a monofunctional thiol compound having one thiol group in one molecule, or a multifunctional thiol compound having two or more thiol groups in one molecule. The thiol compound contained in the resin composition may be only one type or two or more types.

The thiol compound may have a polymerizable group other than a thiol group (for example, a (meth)acryloyl group and a (meth)allyl group) in the molecule, or may not have it. In the present disclosure, a compound containing a thiol group and a polymerizable group other than the thiol group in the molecule is classified as a "thiol compound".

Specific examples of monofunctional thiol compounds include: hexyl mercaptan, 1-heptane mercaptan, 1-octyl mercaptan, 1-nonane mercaptan, 1-decane mercaptan, 3-mercaptopropionic acid, mercaptopropionic acid Methyl ester, methoxybutyl mercaptopropionate, octyl mercaptopropionate, tridecyl mercaptopropionate, 2-ethylhexyl-3-mercaptopropionate, n-octyl-3-mercaptopropionate, etc. .

Specific examples of polyfunctional thiol compounds include: ethylene glycol bis(3-mercaptopropionate), diethylene glycol bis(3-mercaptopropionate), tetraethylene glycol bis(3-mercaptopropionate) Acid ester), 1,2-propanediol bis(3-mercaptopropionate), diethylene glycol bis(3-mercaptobutyrate), 1,4-butanediol bis(3-mercaptopropionate), 1,4-Butanediol bis(3-mercaptobutyrate), 1,8-octanediol bis(3-mercaptopropionate), 1,8-octanediol bis(3-mercaptobutyrate) , Hexanediol dithioglycolate, trimethylolpropane tris (3-mercaptopropionate), trimethylolpropane tris (3-mercaptobutyrate), trimethylolpropane tris (3- Mercapto isobutyrate), trimethylolpropane tris (2-mercaptoisobutyrate), trimethylolpropane trithioglycolate, tris-[(3-mercaptopropionyloxy)-ethyl ]-Isocyanurate, trimethylolethane tris(3-mercaptobutyrate), pentaerythritol tetra(3-mercaptopropionate), pentaerythritol tetra(3-mercaptobutyrate), pentaerythritol tetra(3-mercaptobutyrate) 3-mercaptoisobutyrate), pentaerythritol tetra(2-mercaptoisobutyrate), dipentaerythritol hexa(3-mercaptopropionate), dipentaerythritol hexa(2-mercaptopropionate), dipentaerythritol hexa(3 -Mercaptobutyrate), dipentaerythritol hexa(3-mercaptoisobutyrate), dipentaerythritol hexa(2-mercaptoisobutyrate), pentaerythritol tetrathioglycolate, dipentaerythritol hexathioglycolate, etc. .

From the viewpoint of further improving the adhesion between the wavelength conversion layer and the coating material, heat resistance, and moisture and heat resistance, the thiol compound preferably contains a multifunctional thiol compound. The ratio of the polyfunctional thiol compound to the total amount of the thiol compound is, for example, preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 100% by mass.

The thiol compound may be in the form of a thioether oligomer formed by reacting with a (meth)acrylic compound. The thioether oligomer can be obtained by addition polymerization of a thiol compound and a (meth)acrylic compound in the presence of a polymerization initiator.

When the resin composition contains a thiol compound, relative to the total amount of the resin composition, the content of the thiol compound in the resin composition is, for example, preferably 5 mass% to 80 mass%, more preferably 15 mass% ~70% by mass, more preferably 18% by mass to 60% by mass. If the content of the thiol compound is 5% by mass or more, the adhesion between the wavelength conversion layer and the coating material tends to be further improved, and if the content of the thiol compound is 80% by mass or less, the wavelength conversion layer is heat-resistant Tendency to further increase in performance and resistance to heat and humidity.

B. (Meth) acrylic compound The (meth)acrylic compound may be a monofunctional (meth)acrylic compound having one (meth)acrylic acid group in one molecule, or it may have two or more (meth)acrylic acid groups in one molecule The multifunctional (meth)acrylic compound. The (meth)acrylic compound contained in the resin composition may be one type or two or more types.

Specific examples of the monofunctional (meth)acrylic compound include: (meth)acrylic acid; methyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, (meth)acrylic acid; Base) 2-ethylhexyl acrylate, isononyl (meth)acrylate, n-octyl (meth)acrylate, lauryl (meth)acrylate, stearyl (meth)acrylate, etc. Alkyl (meth)acrylates of 1 to 18; (meth)acrylate compounds having aromatic rings such as benzyl (meth)acrylate and phenoxyethyl (meth)acrylate; (methyl) ) Alkoxyalkyl (meth)acrylates such as butoxyethyl acrylate; Aminoalkyl (meth)acrylates such as N,N-dimethylaminoethyl (meth)acrylate; Diethylene glycol monoethyl ether (meth) acrylate, triethylene glycol monobutyl ether (meth) acrylate, tetraethylene glycol monomethyl ether (meth) acrylate, hexaethylene glycol monomethyl ether (meth) Base) acrylate, octaethylene glycol monomethyl ether (meth)acrylate, nonaethylene glycol monomethyl ether (meth)acrylate, dipropylene glycol monomethyl ether (meth)acrylate, heptapropylene glycol monomethyl ether Polyalkylene glycol monoalkyl ether (meth)acrylate such as (meth)acrylate and tetraethylene glycol monoethyl ether (meth)acrylate; hexaethylene glycol monophenyl ether (meth)acrylate Polyalkylene glycol monoaryl ether (meth)acrylate; cyclohexyl (meth)acrylate, dicyclopentyl (meth)acrylate, isobornyl (meth)acrylate, formaldehyde addition cyclodecyl (Meth)acrylate compounds having an alicyclic structure such as triene (meth)acrylate; (meth)acrylate compounds having a heterocyclic ring such as (meth)acryloylmorpholine and tetrahydrofurfuryl (meth)acrylate Yl)acrylate compound; fluorinated alkyl (meth)acrylate such as heptafluorodecyl (meth)acrylate; 2-hydroxyethyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate , 4-hydroxybutyl (meth)acrylate, triethylene glycol mono(meth)acrylate, tetraethylene glycol mono(meth)acrylate, hexaethylene glycol mono(meth)acrylate, octapropylene glycol (Meth)acrylate compounds having hydroxyl groups such as mono(meth)acrylate; (meth)acrylate compounds having glycidyl groups such as glycidyl (meth)acrylate; isocyanate 2-(2 -(Meth)acrylate compounds having isocyanate groups such as (meth)acryloxyethoxy) ethyl and 2-(meth)acryloxyethyl isocyanate; tetraethylene glycol mono (Meth)acrylate, hexaethylene glycol mono(meth)acrylate, octapropylene glycol mono(meth)acrylate and other polyalkylene glycol mono(meth)acrylates; (meth)acrylamide, N,N-dimethyl(meth)acrylamide, N-isopropyl(meth)acrylamide, N,N-dimethylaminopropyl(meth)acrylamide, N,N -(Meth)acrylamide compounds such as diethyl (meth)acrylamide and 2-hydroxyethyl (meth)acrylamide.

Specific examples of the polyfunctional (meth)acrylic compound include 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9- Alkylene glycol di(meth)acrylate such as nonanediol di(meth)acrylate; Polyalkylene glycol such as polyethylene glycol di(meth)acrylate and polypropylene glycol di(meth)acrylate Di(meth)acrylate; trimethylolpropane tri(meth)acrylate, ethylene oxide addition trimethylolpropane tri(meth)acrylate, isocyanuric acid tris(2-propylene) Tri(meth)acrylate compounds such as oxyethyl) ester; ethylene oxide addition pentaerythritol tetra(meth)acrylate, trimethylolpropane tetra(meth)acrylate, pentaerythritol tetra(meth)acrylate Tetra(meth)acrylate compounds such as acrylate; tricyclodecane dimethanol di(meth)acrylate, cyclohexane dimethanol di(meth)acrylate, 1,3-adamantane dimethanol Di (meth) acrylate, hydrogenated bisphenol A (poly) ethoxy bis (meth) acrylate, hydrogenated bisphenol A (poly) propoxy bis (meth) acrylate, hydrogenated bisphenol F (poly) ) Ethoxy bis (meth) acrylate, hydrogenated bisphenol F (poly) propoxy bis (meth) acrylate, hydrogenated bisphenol S (poly) ethoxy bis (meth) acrylate, hydrogenated bisphenol (Meth)acrylate compounds having an alicyclic structure such as phenol S (poly)propoxydi(meth)acrylate.

From the viewpoint of further improving the heat resistance and moisture and heat resistance of the cured product, the (meth)acrylic compound is preferably a (meth)acrylate compound having an alicyclic structure or an aromatic ring structure. As an alicyclic structure or an aromatic ring structure, an isobornyl skeleton, a tricyclodecane skeleton, a bisphenol skeleton, etc. are mentioned.

The (meth)acrylic compound may be one having an alkoxyl group, or a difunctional (meth)acrylic compound having an alkoxyl group.

As the alkoxyl group, for example, an alkoxyl group having 2 to 4 carbon atoms is preferred, an alkoxyl group having 2 or 3 carbon atoms is more preferred, and an alkoxyl group having 2 carbon atoms is more preferred. . The alkoxylate group contained in the (meth)acrylic compound may be one type or two or more types.

The alkoxyl group-containing compound may also be a polyalkyleneoxy group-containing compound having a polyalkoxyl group containing a plurality of alkoxyl groups.

In the case where the (meth)acrylic compound has alkoxylate groups, the number of alkoxylate groups in one molecule is preferably 2 to 30, more preferably 2 to 20, and still more preferably 3. Pieces to 10 pieces, particularly preferably 3 to 5 pieces.

When the (meth)acrylic compound has an alkoxyl group, it preferably has a bisphenol structure. This tends to be more excellent in heat resistance of the cured product. Examples of the bisphenol structure include a bisphenol A structure and a bisphenol F structure, and among them, a bisphenol A structure is preferred.

Specific examples of the (meth)acrylic compound having an alkoxy group include: alkoxyalkyl (meth)acrylate such as butoxyethyl (meth)acrylate; diethylene glycol monoethyl ether (Meth) acrylate, triethylene glycol monobutyl ether (meth)acrylate, tetraethylene glycol monomethyl ether (meth)acrylate, hexaethylene glycol monomethyl ether (meth)acrylate, eight Ethylene glycol monomethyl ether (meth)acrylate, nonaethylene glycol monomethyl ether (meth)acrylate, dipropylene glycol monomethyl ether (meth)acrylate, heptapropylene glycol monomethyl ether (meth)acrylate , Polyalkylene glycol monoalkyl ether (meth)acrylate such as tetraethylene glycol monoethyl ether (meth)acrylate; Polyalkylene glycol such as hexaethylene glycol monophenyl ether (meth)acrylate Monoaryl ether (meth)acrylate; (meth)acrylate compounds having heterocycles such as tetrahydrofurfuryl (meth)acrylate; triethylene glycol mono(meth)acrylate, tetraethylene glycol (Meth)acrylate compounds having hydroxyl groups such as mono(meth)acrylate, hexaethylene glycol mono(meth)acrylate, and octapropylene glycol mono(meth)acrylate; glycidyl (meth)acrylate (Meth)acrylate compounds having glycidyl groups; polyalkylene glycol di(meth)acrylates such as polyethylene glycol di(meth)acrylate and polypropylene glycol di(meth)acrylate; Addition of ethylene oxide to trimethylolpropane tri(meth)acrylate and other tri(meth)acrylate compounds; addition of ethylene oxide to pentaerythritol tetra(meth)acrylate and other tetra(meth)acrylate compounds Acrylate compound; ethoxylated bisphenol A type di(meth)acrylate, propoxylated bisphenol A type di(meth)acrylate, propoxylated ethoxylated bisphenol A type bis( Bisphenol-type di(meth)acrylate compounds such as meth)acrylate. As the alkoxy-containing compound, among them, ethoxylated bisphenol A type di(meth)acrylate, propoxylated bisphenol A type di(meth)acrylate and propoxylated ethyl acrylate are preferred. The oxylated bisphenol A type di(meth)acrylate is more preferably the ethoxylated bisphenol A type di(meth)acrylate.

When the resin composition contains a (meth)acrylic compound, the content of the (meth)acrylic compound in the resin composition may be, for example, 40% by mass to 90% by mass relative to the total amount of the resin composition. It can be 50% to 80% by mass.

C. (Methyl) allyl compound The (meth)allyl compound may be a monofunctional (meth)allyl compound having one (meth)allyl group in one molecule, or it may be a monofunctional (meth)allyl compound having two or more (methyl) allyl groups in one molecule. ) Allyl polyfunctional (meth)allyl compounds. The (meth)allyl compound contained in the resin composition may be only one type or two or more types.

The (meth)allyl compound may or may not have a polymerizable group other than the (meth)allyl group (for example, a (meth)acryloyl group) in the molecule. In the present disclosure, (meth)allyl compounds having a polymerizable group other than (meth)allyl in the molecule (excluding thiol compounds) are classified as "(meth)allyl compounds ".

Specific examples of monofunctional (meth)allyl compounds include (meth)allyl acetate, (meth)allyl n-propionic acid, (meth)allyl benzoate, and acetic acid ( (Meth)allyl phenyl ester, (meth)allyl phenoxy acetate, (meth)allyl methyl ether, (meth)allyl glycidyl ether, etc.

Specific examples of polyfunctional (meth)allyl compounds include di(meth)allyl benzenedicarboxylate, di(meth)allyl cyclohexanedicarboxylate, and maleic Di(meth)allyl acid, di(meth)allyl adipate, di(meth)allyl phthalate, di(meth)allyl isophthalate, p-benzene Di(meth)allyl dicarboxylate, glycerol bis(meth)allyl ether, trimethylolpropane bis(meth)allyl ether, pentaerythritol bis(meth)allyl ether, isotrimethyl 1,3-bis(meth)allyl-5-glycidyl cyanurate, tri(meth)allyl cyanurate, tri(meth)allyl isocyanurate, partial Tris(meth)allyl trimellitate, pyromellitic tetra(meth)allyl ester, 1,3,4,6-tetra(meth)allyl glycoluril, 1,3,4, 6-Tetra(meth)allyl-3a-methyl glycoluril, 1,3,4,6-tetra(meth)allyl-3a,6a-dimethyl glycoluril, etc.

From the viewpoints of the heat resistance and heat resistance of the cured product, the (meth)allyl compound is preferably selected from the group consisting of isocyanuric acid tri(meth)allyl isocyanurate and the like. The group consisting of backbone compounds, tris(meth)allyl cyanurate, bis(meth)allyl benzenedicarboxylate, and bis(meth)allyl cyclohexanedicarboxylate At least one of them is more preferably a compound having an isocyanurate skeleton, and still more preferably tri(meth)allyl isocyanurate.

When the resin composition contains a (meth)allyl compound, the content rate of the (meth)allyl compound in the resin composition may be, for example, 10% by mass to 50% relative to the total amount of the resin composition. The mass% may be 15% to 45% by mass.

In one embodiment, the polymerizable compound may include a thioether oligomer as a thiol compound and a (meth)allyl compound (preferably a polyfunctional (meth)allyl compound).

In the case where the polymerizable compound contains a thioether oligomer as a thiol compound and a (meth)allyl compound, and a quantum dot phosphor is used as the phosphor, the quantum dot phosphor is preferably dispersed in The state of a dispersion in a silicone compound as a dispersion medium.

In one embodiment, the polymerizable compound may also include a thiol compound other than a thioether oligomer, and a (meth)acrylic compound (preferably a polyfunctional (meth)acrylic compound, more preferably a polyfunctional (meth)acrylic compound). It is a bifunctional (meth)acrylic compound).

In the case where the polymerizable compound contains a thiol compound other than a thioether oligomer and a (meth)acrylic compound, and a quantum dot phosphor is used as the phosphor, the quantum dot phosphor is preferably The state of a dispersion liquid dispersed in a (meth)acrylic compound as a dispersion medium, preferably a monofunctional (meth)acrylic compound, more preferably isobornyl (meth)acrylate.

(Photopolymerization initiator) The type of the photopolymerization initiator contained in the resin composition is not particularly limited, and examples thereof include compounds that generate radicals by irradiation with active energy rays such as ultraviolet rays.

Specific examples of the photopolymerization initiator include benzophenone, N,N'-tetraalkyl-4,4'-diaminobenzophenone, 2-benzyl-2-dimethyl Amino-1-(4-morpholinylphenyl)-butanone-1, 2-methyl-1-[4-(methylthio)phenyl]-2-morpholinyl-acetone-1, 4 ,4'-bis(dimethylamino)benzophenone (also known as "Michler's ketone"), 4,4'-bis(diethylamino)benzophenone, 4-methoxy-4'-dimethylamino benzophenone, 1-hydroxycyclohexyl phenyl ketone, 1-(4-isopropylphenyl)-2-hydroxy-2-methylpropane- 1-ketone, 1-(4-(2-hydroxyethoxy)-phenyl)-2-hydroxy-2-methyl-1-propan-1-one, 2-hydroxy-2-methyl-1- Aromatic ketone compounds such as phenylpropane-1-one; quinone compounds such as alkylanthraquinone and phenanthrenequinone; benzoin compounds such as benzoin and alkylbenzoin; benzoin ether compounds such as benzoin alkyl ether and benzoin phenyl ether ; Benzyl derivatives such as benzyl dimethyl ketal; 2-(o-chlorophenyl)-4,5-diphenylimidazole dimer, 2-(o-chlorophenyl)-4,5-di (M-methoxyphenyl) imidazole dimer, 2-(o-fluorophenyl)-4,5-diphenylimidazole dimer, 2-(o-methoxyphenyl)-4,5-di Phenylimidazole dimer, 2,4-bis(p-methoxyphenyl)-5-phenylimidazole dimer, 2-(2,4-dimethoxyphenyl)-4,5-di 2,4,5-triarylimidazole dimer such as phenylimidazole dimer; acridine derivatives such as 9-phenylacridine, 1,7-(9,9'-acridinyl)heptane, etc. ; 1,2-octanedione 1-[4-(phenylthio)-2-(O-benzyl oxime)], ethyl ketone 1-[9-ethyl-6-(2-methylbenzene (Formyl)-9H-carbazol-3-yl]-1-(O-acetyloxime) and other oxime ester compounds; 7-diethylamino-4-methylcoumarin and other coumarins Thioxanthone compounds; 2,4-diethylthioxanthone and other thioxanthone compounds; 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, 2,4,6-trimethylthioxanthone Phosphine oxide compounds such as methylbenzyl-phenyl-ethoxy-phosphine oxide and the like. The resin composition may contain one kind of photopolymerization initiator alone, or may contain two or more kinds of photopolymerization initiators in combination.

From the standpoint of curability, the photopolymerization initiator is preferably at least one selected from the group consisting of oxyphosphine oxide compounds, aromatic ketone compounds, and oxime ester compounds, and more preferably selected from the group consisting of oxyphosphine oxide compounds, aromatic ketone compounds, and oxime ester compounds. At least one of the group consisting of a phosphine oxide compound and an aromatic ketone compound is more preferably an acyl phosphine oxide compound.

Relative to the total amount of the resin composition, the content of the photopolymerization initiator in the resin composition is, for example, preferably 0.1% by mass to 5% by mass, more preferably 0.1% by mass to 3% by mass, and still more preferably 0.1 Mass% to 1.5% by mass. If the content of the photopolymerization initiator is 0.1% by mass or more, the sensitivity of the resin composition tends to become sufficient. If the content of the photopolymerization initiator is 5% by mass or less, there is a tendency for the resin composition The influence of hue and the decrease in storage stability tend to be suppressed.

(Light diffusion material) From the viewpoint of improving the light conversion efficiency, the resin composition may further contain a light diffusing material. As a specific example of a light diffusion material, titanium oxide, barium sulfate, zinc oxide, calcium carbonate, etc. are mentioned. Among these, from the viewpoint of light scattering efficiency, the light diffusion material is preferably titanium oxide. The titanium oxide may be rutile-type titanium oxide or anatase-type titanium oxide, and is preferably rutile-type titanium oxide.

The average particle diameter of the light diffusion material is preferably 0.1 μm to 1 μm, more preferably 0.2 μm to 0.8 μm, and still more preferably 0.2 μm to 0.5 μm. In the present disclosure, the average particle size of the light diffusion material can be measured as follows. When the light diffusion material is contained in the resin composition, the extracted light diffusion material is dispersed in purified water containing a surfactant to obtain a dispersion liquid. When using this dispersion liquid to measure the volume-based particle size distribution by a laser diffraction particle size distribution measuring device (for example, Shimadzu Corporation, SALD-3000J), when the cumulative amount from the small diameter side reaches 50% The value of (median particle diameter (D50)) is the average particle diameter of the light diffusion material. As a method of extracting the light diffusing material from the resin composition, for example, it can be obtained by diluting the resin composition with a liquid medium, and separating and recovering the light diffusing material by precipitation by centrifugal separation treatment or the like. The average particle diameter of the light diffusion material in the cured product obtained by curing the resin composition containing the light diffusion material can be calculated by observing the particles using a scanning electron microscope to calculate the circle-equivalent diameter (the long diameter and the long diameter) of 50 particles The geometric mean of the short diameter) is calculated as the arithmetic mean.

From the viewpoint of suppressing aggregation of the light diffusing material in the resin composition, the light diffusing material preferably has an organic layer containing an organic material on at least a part of the surface. Examples of the organic substances contained in the organic substance layer include organosilanes, organosiloxanes, fluorosilanes, organophosphates, organophosphate compounds, organophosphinates, organosulfonic acid compounds, carboxylic acids, carboxylic acid esters, and carboxylates. Acid derivatives, amides, hydrocarbon waxes, polyolefins, polyolefin oligomers, polyols, polyol derivatives, alkanolamines, alkanolamine derivatives, organic dispersants, etc. The organic substance contained in the organic substance layer preferably contains polyol, organosilane, etc., and more preferably contains at least one of polyol or organosilane. Specific examples of organosilanes include: octyltriethoxysilane, nonyltriethoxysilane, decyltriethoxysilane, dodecyltriethoxysilane, and tridecyltriethoxysilane. Oxysilane, tetradecyl triethoxy silane, pentadecyl triethoxy silane, hexadecyl triethoxy silane, heptadecyl triethoxy silane, octadecyl triethyl Oxysilane and so on. Specific examples of organosiloxanes include: polydimethyl siloxane (PDMS), polymethyl hydrosiloxane (PMHS), PMHS terminated with trimethylsilyl groups Polysiloxanes derived from functionalization (hydrosilation) of olefins, etc. Specific examples of organic phosphates include, for example, n-octyl phosphonic acid and its esters, n-decyl phosphonic acid and its esters, 2-ethylhexyl phosphonic acid and its esters, and camphor group (camphyl) phosphonic acid and its ester. As a specific example of an organic phosphoric acid compound, an organic acidic phosphoric acid ester, an organic pyrophosphate, an organic polyphosphate, an organic metaphosphate, these salts, etc. are mentioned. Specific examples of organic phosphinic acid esters include, for example, n-hexyl phosphinic acid and its esters, n-octyl phosphinic acid and its esters, di-n-hexyl phosphinic acid and its esters, and di-n-octyl phosphinic acid. Phosphonic acid and its esters. Specific examples of organic sulfonic acid compounds include alkyl sulfonic acids such as hexyl sulfonic acid, octyl sulfonic acid and 2-ethylhexyl sulfonic acid, these alkyl sulfonic acids and sodium, calcium, magnesium, aluminum, Salts such as metal ions such as titanium, ammonium ions, and organic ammonium ions such as triethanolamine. Specific examples of carboxylic acids include maleic acid, malonic acid, fumaric acid, benzoic acid, phthalic acid, stearic acid, oleic acid, linoleic acid, and the like. Specific examples of carboxylic acid esters include the combination of the carboxylic acid and ethylene glycol, propylene glycol, trimethylolpropane, diethanolamine, triethanolamine, glycerin, hexanetriol, erythritol, and mannitol. , Sorbitol, pentaerythritol, bisphenol A, hydroquinone, phloroglucinol and other hydroxyl compounds generated by the reaction of esters and partial esters. Specific examples of amides include amide stearate, amide oleate, and erucamide. Specific examples of polyolefins and their oligomers include polyethylene, polypropylene, ethylene and one or two or more compounds selected from propylene, butene, vinyl acetate, acrylate, acrylamide, etc. Copolymers and so on. As a specific example of a polyhydric alcohol, glycerol, trimethylolethane, trimethylolpropane, etc. are mentioned. As a specific example of alkanolamine, diethanolamine, triethanolamine, etc. are mentioned. Specific examples of the organic dispersant include citric acid, polyacrylic acid, polymethacrylic acid, and polymer organic dispersants having functional groups such as anionic, cationic, amphoteric, and nonionic. If the aggregation of the light diffusion material in the resin composition is suppressed, the dispersibility of the light diffusion material in the cured product tends to improve.

The light diffusion material may have a metal oxide layer containing a metal oxide on at least a part of the surface. Examples of the metal oxide contained in the metal oxide layer include silicon dioxide, aluminum oxide, zirconium oxide, phosphoria, boria, and the like. The metal oxide layer may be one layer or two or more layers. When the light diffusion material has two metal oxide layers, it is preferably one containing a first metal oxide layer containing silicon dioxide and a second metal oxide layer containing aluminum oxide. Since the light diffusion material has a metal oxide layer, the dispersibility of the light diffusion material in the cured product tends to be improved.

When the light diffusing material has an organic layer and a metal oxide layer containing organics, the metal oxide layer and the organic layer are preferably provided on the surface of the light diffusing material in the order of the metal oxide layer and the organic layer. In the case where the light diffusion material has an organic layer and two metal oxide layers, on the surface of the light diffusion material, a first metal oxide layer including silicon dioxide, a second metal oxide layer including aluminum oxide, and The organic layer is preferably provided in the order of the first metal oxide layer, the second metal oxide layer, and the organic layer (the organic layer becomes the outermost layer).

When the resin composition contains a light diffusing material, the content of the light diffusing material in the wavelength conversion layer formed by curing the resin composition is preferably, for example, 0.1% by mass to 1.0 relative to the total amount of the wavelength conversion layer. % By mass, more preferably 0.2% by mass to 1.0% by mass, and still more preferably 0.3% by mass to 1.0% by mass.

(Liquid medium) The resin composition may further contain a liquid medium. The so-called liquid medium refers to a medium that is in a liquid state at room temperature (25°C).

Specific examples of the liquid medium include: acetone, methyl ethyl ketone, methyl-n-propyl ketone, methyl isopropyl ketone, methyl-n-butyl ketone, methyl isobutyl ketone, methyl Base-n-pentyl ketone, methyl-n-hexyl ketone, diethyl ketone, dipropyl ketone, diisobutyl ketone, trimethylnonanone, cyclohexanone, cyclopentanone, methylcyclohexanone, Ketone solvents such as 2,4-pentanedione and acetonylacetone; diethyl ether, methyl ethyl ether, methyl-n-propyl ether, diisopropyl ether, tetrahydrofuran, methyltetrahydrofuran, dioxane , Dimethyl dioxane, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, ethylene glycol di-n-propyl ether, ethylene glycol di-n-butyl ether, diethylene glycol dimethyl ether Base ether, diethylene glycol diethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol methyl-n-propyl ether, diethylene glycol methyl-n-butyl ether, diethylene glycol Di-n-propyl ether, diethylene glycol di-n-butyl ether, diethylene glycol methyl-n-hexyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene two Alcohol methyl ethyl ether, triethylene glycol methyl-n-butyl ether, triethylene glycol di-n-butyl ether, triethylene glycol methyl-n-hexyl ether, tetraethylene glycol dimethyl ether, Tetraethylene glycol diethyl ether, tetraethylene glycol methyl ethyl ether, tetraethylene glycol methyl-n-butyl ether, tetraethylene glycol di-n-butyl ether, tetraethylene glycol methyl-n-hexyl Base ether, propylene glycol dimethyl ether, propylene glycol diethyl ether, propylene glycol di-n-propyl ether, propylene glycol di-n-butyl ether, dipropylene glycol dimethyl ether, dipropylene glycol diethyl ether, dipropylene glycol methyl ethyl Base ether, dipropylene glycol methyl-n-butyl ether, dipropylene glycol di-n-propyl ether, dipropylene glycol di-n-butyl ether, dipropylene glycol methyl-n-hexyl ether, tripropylene glycol dimethyl ether, tripropylene glycol two Ethyl ether, tripropylene glycol methyl ethyl ether, tripropylene glycol methyl-n-butyl ether, tripropylene glycol di-n-butyl ether, tripropylene glycol methyl-n-hexyl ether, tetrapropylene glycol dimethyl ether, tetrapropylene glycol two Ethyl ether, tetrapropylene glycol methyl ethyl ether, tetrapropylene glycol methyl-n-butyl ether, tetrapropylene glycol di-n-butyl ether, tetrapropylene glycol methyl-n-hexyl ether and other ether solvents; propylene carbonate, carbonic acid Carbonate solvents such as ethylene and diethyl carbonate; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, second butyl acetate, n-propyl acetate Amyl ester, second amyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, 2-(2-butoxyethyl acetate) Oxy) ethyl ester, benzyl acetate, cyclohexyl acetate, methyl cyclohexyl acetate, nonyl acetate, methyl acetyl acetate, ethyl acetyl acetate, diethylene glycol methyl ether acetate, diethyl acetate Glycol monoethyl ether, dipropylene glycol methyl ether acetate, dipropylene glycol ethyl ether acetate, glycol diacetate, methoxytriethylene glycol acetate, ethyl propionate, n-butyl propionate, propionic acid Isoamyl ester, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-pentyl lactate, ethylene glycol methyl ether propionate, ethylene glycol ethyl ether Propionate, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetic acid Ester, propylene glycol propyl ether acetate, γ-butyrolactone, γ-valerolactone and other ester solvents; acetonitrile, N-methylpyrrolidone, N-ethylpyrrolidone, N-propylpyrrolidine Ketone, N-butylpyrrolidone, N-hexylpyrrolidone, N-cyclohexylpyrrolidone, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl Aprotic polar solvents such as sulfite; methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, second butanol, tertiary butanol, n-pentanol, isoamyl alcohol, 2- Methyl butanol, second pentanol, third pentanol, 3-methoxybutanol, n-hexanol, 2-methylpentanol, second hexanol, 2-ethylbutanol, second heptanol, N-octanol, 2-ethylhexanol, sec-octanol, n-nonanol, n-decyl alcohol, sec-undecyl alcohol, trimethylnonanol, sec-tetradecanol, sec-heptadecanol , Cyclohexanol, methylcyclohexanol, benzyl alcohol, ethylene glycol, 1,2-propanediol, 1,3-butanediol, diethylene glycol, dipropylene glycol, triethylene glycol, tripropylene glycol and other alcohols Solvent; ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monophenyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono- N-butyl ether, diethylene glycol mono-n-hexyl ether, triethylene glycol monoethyl ether, tetraethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol Glycol monoether solvents such as monoethyl ether and tripropylene glycol monomethyl ether; terpinene, terpineol, myrcene, allo-ocylene, limonene, dipentene, pinene, parvellone, basil Terpene solvents such as ene and phellandrene; pure silicone oils such as dimethyl silicone oil, methyl phenyl silicone oil, methyl hydrogen silicone oil, etc.; amino modified silicone oil, epoxy modified silicone oil, carboxy modified silicone oil, methanol Modified silicone oil, sulfhydryl modified silicone oil, heterogeneous functional group modified silicone oil, polyether modified silicone oil, methylstyrene modified silicone oil, hydrophilic special modified silicone oil, high-grade alkoxy modified silicone oil, high-grade fatty acid modification Modified silicone oil such as silicone oil, fluorine-modified silicone oil; butyric acid, valeric acid, caproic acid, heptanoic acid, caprylic acid, nonanoic acid, capric acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, etc. Saturated aliphatic monocarboxylic acids with 4 or more carbons such as hexadecanoic acid, heptadecanoic acid, octadecanoic acid, nonadecosic acid, eicosanoic acid, and eicosenoic acid; oleic acid, elaidic acid, linoleic acid , Palmitoleic acid and other unsaturated aliphatic monocarboxylic acids with 8 or more carbon atoms. When the resin composition contains a liquid medium, the resin composition may contain one kind of liquid medium alone, or may contain two or more kinds of liquid media in combination.

When the resin composition contains a liquid medium, the content of the liquid medium in the resin composition is preferably, for example, 1% by mass to 10% by mass, and more preferably 4% by mass relative to the total amount of the resin composition. ~10% by mass, more preferably 4% by mass to 7% by mass.

(Other ingredients) The resin composition may further contain components other than the above-mentioned components. For example, the resin composition may further contain components such as a polymerization inhibitor, a silane coupling agent, a surfactant, an adhesion imparting agent, an antioxidant, and a carboxylic acid such as acetic acid. Each component may be used individually by 1 type, and may use 2 or more types together.

(Preparation method of resin composition) The resin composition can be prepared by mixing a phosphor, a polymerizable compound, a photopolymerization initiator, and other components as necessary by a conventional method.

The wavelength conversion layer may be formed by curing one type of resin composition, or may be formed by curing two or more types of resin composition. For example, in the case where the wavelength conversion member is in the form of a film, the wavelength conversion layer may be laminated with a first cured layer formed by curing a resin composition containing a first phosphor, and a first cured layer formed by curing a resin composition containing a first phosphor, A second cured layer formed by curing a resin composition of a second phosphor with a different light body.

The average thickness of the wavelength conversion layer is not particularly limited. For example, it is preferably 50 μm to 200 μm, more preferably 50 μm to 150 μm, and still more preferably 70 μm to 120 μm. If the average thickness of the wavelength conversion layer is 50 μm or more, the wavelength conversion efficiency tends to be further improved. If the average thickness of the wavelength conversion layer is 200 μm or less, the backlight unit tends to be thinner when the wavelength conversion member is applied to the backlight unit described later. The average thickness of the wavelength conversion layer can be obtained, for example, as an arithmetic average of the thicknesses of any three locations measured with a micrometer.

From the viewpoint of further improving the adhesiveness, the loss tangent (tanδ) of the wavelength conversion layer measured under the conditions of a frequency of 10 Hz and a temperature of 25° C. measured by dynamic viscoelasticity is preferably 0.4 to 1.5, more preferably 0.4 to 1.2, more preferably 0.4 to 0.6. The loss tangent (tanδ) of the wavelength conversion layer can be measured using a dynamic viscoelasticity measuring device (for example, Rheometric Scientific, Solid Analyzer RSA-III).

From the viewpoint of further improving adhesion, heat resistance, and moisture and heat resistance, the glass transition temperature (Tg) of the wavelength conversion layer is preferably 85°C or higher, more preferably 85°C to 160°C, and still more preferably 90°C ～120℃. The glass transition temperature (Tg) of the wavelength conversion layer can be measured using a dynamic viscoelasticity measuring device (for example, Rheometric Scientific, Solid Analyzer RSA-III) at a frequency of 10 Hz.

In addition, from the viewpoint of further improving adhesion, heat resistance, and moisture and heat resistance, the storage elastic coefficient of the wavelength conversion layer measured under the conditions of a frequency of 10 Hz and a temperature of 25° C. is preferably 1×10 ⁷ Pa~ 1×10 ¹⁰ Pa, more preferably 5×10 ⁷ Pa to 1×10 ¹⁰ Pa, still more preferably 5×10 ⁷ Pa to 5×10 ⁹ Pa. The storage elastic coefficient of the cured resin can be measured using a dynamic viscoelasticity measuring device (for example, Rheometric Scientific, Solid Analyzer RSA-III).

The wavelength conversion layer can be obtained, for example, by forming a coating film, a molded body, etc. of the resin composition, and drying treatment as necessary, and then irradiating active energy rays such as ultraviolet rays. The wavelength and irradiation amount of the active energy rays can be appropriately set according to the composition of the resin composition. In one aspect, ultraviolet rays with a wavelength of 280 nm to 400 nm are irradiated with an irradiation amount of ^{100 mJ/cm 2} to 5000 mJ/cm ^2. Examples of ultraviolet sources include low-pressure mercury lamps, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, carbon arc lamps, metal halide lamps, xenon lamps, chemical lamps, black light lamps, microwave-excited mercury lamps, and the like.

An example of the schematic configuration of the wavelength conversion member is shown in FIG. 1. However, the wavelength conversion member of the present disclosure is not limited to the configuration of FIG. 1.

The wavelength conversion member 10 shown in FIG. 1 has a wavelength conversion layer 11 that is a film-shaped cured product, and film-shaped cladding materials 12A and cladding materials 12B provided on both surfaces of the wavelength conversion layer 11. The type and average thickness of the covering material 12A and the covering material 12B may be the same or different. The covering material 12A and the covering material 12B may be roughened.

The wavelength conversion member of the structure shown in FIG. 1 can be manufactured by the following manufacturing method, for example.

First, a resin composition for forming a wavelength conversion layer is applied to the surface of a film-like covering material (hereinafter, also referred to as a “first covering material”) that is continuously conveyed to form a coating film. The method of applying the resin composition is not particularly limited, and examples thereof include die coating, curtain coating, extrusion coating, bar coating, and roll coating.

Then, a film-like covering material (hereinafter, also referred to as a “second covering material”) that is continuously conveyed is bonded to the coating film of the resin composition.

Then, the active energy rays are irradiated from the side of the covering material through which the active energy rays of the first covering material and the second covering material are permeable, thereby curing the coating film to form a cured product layer. Thereafter, by cutting out a predetermined size, the wavelength conversion member having the configuration shown in FIG. 1 can be obtained.

Furthermore, in the case that neither the first coating material nor the second coating material can transmit the active energy rays, the active energy rays can also be irradiated to the coating film before the second coating material is laminated, and A hardened layer is formed, and then the second covering material is attached.

"Backlight Unit" The backlight unit of the present disclosure has a light source and the wavelength conversion member of the present disclosure.

From the viewpoint of improving color reproducibility, the backlight unit is preferably one that has been light sourced with multiple wavelengths. As a preferable aspect, a backlight unit that emits blue light, green light, and red light can be cited. The blue light has a central emission wavelength in the wavelength region of 430 nm to 480 nm, and has a half-value width. Is a luminous intensity peak below 100 nm, the green light has a luminous center wavelength in the wavelength region from 520 nm to 560 nm, and has a luminous intensity peak with a half-value width of 100 nm or less, and the red light has a luminous intensity peak at 600 nm to 560 nm. The 680 nm wavelength region has an emission center wavelength and a luminous intensity peak with a half-value width of 100 nm or less. In addition, the half-value width of the luminous intensity peak refers to the peak width at 1/2 height of the peak height.

From the viewpoint of further improving color reproducibility, the emission center wavelength of the blue light emitted by the backlight unit is preferably in the range of 440 nm to 475 nm. From the same viewpoint, the emission center wavelength of the green light emitted by the backlight unit is preferably in the range of 520 nm to 545 nm. In addition, from the same viewpoint, the emission center wavelength of the red light emitted by the backlight unit is preferably in the range of 610 nm to 640 nm.

In addition, from the viewpoint of further improving color reproducibility, the half-value width of each luminous intensity peak of the blue light, green light, and red light emitted by the backlight unit is preferably 80 nm or less, and more preferably 50 nm Hereinafter, it is more preferably 40 nm or less, particularly preferably 30 nm or less, and extremely preferably 25 nm or less.

As the light source of the backlight unit, for example, a light source that emits blue light having an emission center wavelength in a wavelength region of 430 nm to 480 nm can be used. As the light source, for example, a light emitting diode (LED) and a laser can be cited. In the case of using a light source emitting blue light, the wavelength conversion member preferably includes at least a quantum dot phosphor R emitting red light and a quantum dot phosphor G emitting green light. Thereby, white light can be obtained from the red light and green light emitted from the wavelength conversion member and the blue light transmitted through the wavelength conversion member.

In addition, as the light source of the backlight unit, for example, a light source that emits ultraviolet light having an emission center wavelength in a wavelength region of 300 nm to 430 nm may be used. Examples of light sources include LEDs and lasers. In the case of using a light source that emits ultraviolet light, the wavelength conversion member preferably includes a quantum dot phosphor R and a quantum dot phosphor G, and includes a quantum dot phosphor B that is excited by excitation light and emits blue light. Thereby, white light can be obtained by the red light, green light, and blue light emitted from the wavelength conversion member.

The backlight unit of the present disclosure may be an edge light method or a direct type method.

An example of a schematic configuration of a backlight unit of the edge light method is shown in FIG. 2.

The backlight unit 20 shown in Figure 2 includes: a light source 21 emits blue light L _B; light guide plate 22, after the light source 21 emitted from the blue light L _B for emitting light guide; wavelength converting member 10, the light guide plate 22 disposed facing The retroreflective member 23 is arranged to face the light guide plate 22 with the wavelength conversion member 10 interposed therebetween; and the reflective plate 24 is arranged to face the wavelength conversion member 10 with the light guide plate 22 therebetween. The wavelength conversion member 10 of the blue light L _B as part of the excitation light and emits red light L _R and the green light L _G, and L _R emits red light and the green light L _G and the blue excitation light does not become light L _B. With the red light L _R , green light L _G , and blue light L _{B , white light L W is} emitted from the retroreflective member 23.

"Image Display Device" The image display device of the present disclosure includes the backlight unit of the present disclosure. The image display device is not particularly limited, and for example, a liquid crystal display device can be cited.

An example of the schematic configuration of the liquid crystal display device is shown in FIG. 3.

The liquid crystal display device 30 shown in FIG. 3 includes a backlight unit 20 and a liquid crystal cell unit 31 arranged opposite to the backlight unit 20. The liquid crystal cell cell 31 has a configuration in which the liquid crystal cell 32 is arranged between the polarizing plate 33A and the polarizing plate 33B.

The driving method of the liquid crystal cell 32 is not particularly limited. Examples include: Twisted Nematic (TN) method, Super Twisted Nematic (STN) method, Vertical Alignment (VA) method, and in-plane Switching (In-Plane-Switching, IPS) method, optically compensated birefringence (Optically Compensated Birefringence, OCB) method, etc. [Example]

Hereinafter, the present invention will be described in detail through examples, but the present invention is not limited to these examples.

<Examples and Comparative Examples> (Preparation of curable composition) Each component shown in Table 1 was mixed in the compounding amount (unit: mass part) shown in this table, and the curable composition of an Example and a comparative example were prepared, respectively.

In addition, as the (meth)acrylic compound, tricyclodecane dimethanol diacrylate (Shin Nakamura Chemical Industry Co., Ltd., A-DCP) and ethoxylated bisphenol A diacrylate (Shin Nakamura Chemical Industry Co., Ltd.) were used as the (meth)acrylic compound. Co., Ltd., ABE-300; compounds containing alkoxy groups).

As the thiol compound, pentaerythritol tetrakis (3-mercaptopropionate) (SC Organic Chemical Co., Ltd., PEMP) was used.

As the photopolymerization initiator, 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide (BASF, IRGACURE TPO) was used.

As the quantum dot phosphor dispersion, a CdSe/ZnS (core/shell) dispersion (Nanosys, Gen3.5 QD Concentrate) was used. As a dispersion medium of this CdSe/ZnS (core/shell) dispersion liquid, isobornyl acrylate (IBOA) is used. The CdSe/ZnS (core/shell) dispersion contains more than 86% by mass of isobornyl acrylate.

As the carboxylic acid, acetic acid is used.

As the light diffusing material, titanium oxide (Ti-Pure R-706 from Chemours, particle size 0.36 μm) was used. On the surface of the titanium oxide, the first metal oxide layer containing silicon oxide, the second metal oxide layer containing aluminum oxide, and the organic layer containing polyol compounds follow the first metal oxide layer, the second metal oxide layer and the The order of the organic layer is arranged.

[Table 1] Wavelength conversion layer A Wavelength conversion layer B (Meth) acrylic compound A-DCP 77.35 0.00 (Meth) acrylic compound (contains alkoxy group) ABE-300 0.00 67.68 Thiol compound PEMP 19.34 29.01 Photopolymerization initiator TPO 0.50 0.50 Quantum dot phosphor IBOA dispersion Gen3.5 QD Concentrate 1.61 1.61 carboxylic acid Acetic acid 0.50 0.50 Light diffuser Titanium Oxide 0.70 0.70

(Manufacturing of wavelength conversion components) Each curable composition obtained in the above is applied to any one of the following three different barrier films in a thickness of 70 μm to 90 μm to form a coating film. Table 2 shows the thickness of the curable composition and wavelength conversion layer used, and the type of barrier film. Barrier film 1: Barrier film with an average thickness of 75 μm (with barrier components vapor-deposited on one side of the PET film) Barrier film 2: Barrier film with an average thickness of 25 μm (with barrier components sputtered on one side of the PET film) Barrier film 3: Barrier film with an average thickness of 103 μm (with a barrier component coated on one side of the PET film)

On the coating film, the same barrier film as the barrier film on which the coating film was formed was attached, and ultraviolet radiation was irradiated using an ultraviolet irradiation device (Eye Graphics Co., Ltd.) (irradiation amount: 1000 mJ) /cm ² ), thereby respectively obtaining wavelength conversion members in which coating materials are arranged on both sides of the wavelength conversion layer including the cured resin.

(Storage elasticity coefficient) Each wavelength conversion member obtained in the above was cut into a size of 5 mm in width and 40 mm in length to obtain a wavelength conversion member for evaluation. Then, use a dynamic viscoelasticity measuring device (Rheometric Scientific, Solid Analyzer RSA-III) in the "tension mode; distance between chucks: 25 mm; frequency: 10 Hz; measurement Temperature range: -20°C to 180°C; temperature rise rate: 10°C/min" The measurement was performed, and the storage elastic coefficient (E') at 30°C of the wavelength conversion member for evaluation was obtained. Table 2 shows the measured storage elasticity coefficient.

(Specific value) Each wavelength conversion member obtained in the above was cut into a size of 20 mm in width and 20 cm in length to obtain a wavelength conversion member for evaluation. On a table with a height of 10 cm or more, fix it so that one end of the processed wavelength conversion member protrudes 10 cm from the table to the outside, and measure how many mm the tip of the protruding wavelength conversion member is relative to the horizontal plane of the table. Below. The measured specific values are shown in Table 2.

[Evaluation] (Curl amount) Wrap each wavelength conversion member obtained above on a 6-inch diameter roll core, and after standing for 1000 hours at 25°C, it is punched into a rectangle of 1470 mm×850 mm, and 50 sheets are stacked and clamped. In the glass plate, it was allowed to stand at 45°C for 24 hours, at 60°C for 4 hours, at 60°C for 10 hours, or at 85°C for 4 hours to obtain a wavelength conversion member for evaluation. The amount of curl (amount of warpage) was set to the maximum value when measured at 6 points at the end of the wavelength conversion member after press processing. The results are shown in Table 2.

(Optical characteristics) The wavelength conversion members obtained above were wound on a 6-inch diameter core, and after standing for 1000 hours at 25°C, they were punched into a rectangle of 1470 mm × 850 mm, and a spectroradiometer was used (photo study ( PHOTO RESEARCH) company, PR-655) measure the brightness. After measuring the brightness, stack 50 pieces of the press-processed wavelength conversion members and clamp them in a glass plate, and let stand at 45°C for 24 hours, at 60°C for 4 hours, and at 60°C for 10 hours. Or let stand at 85°C for 4 hours, use a spectroradiometer (Photo Research, PR-655) to measure the brightness again, and compare the brightness obtained in the first measurement and the brightness obtained in the second measurement The difference of the white point (White Point) was evaluated. The results are shown in Table 2. In Table 2, when the white point difference is within ±0.001 and the brightness reduction is 3% or less, it is expressed as A, and in other cases, it is expressed as B.

[Table 2] unit Example 1 Example 2 Example 3 Example 4 Example 5 Comparative example 1 Comparative example 2 Comparative example 3 Coating material (barrier film) - 1 1 1 1 2 3 3 3 Wavelength conversion layer - A B A A A A A A The thickness of the wavelength conversion layer μm 80 80 70 90 80 80 70 90 Specific value mm 11.1 10.5 10.1 10.5 26.3 4.2 4.0 4.3 Storage elasticity coefficient (30℃) GPa 3.6 2.1 3.6 3.5 3.0 4.3 4.3 4.2 Curl 45°C/24 hours mm 1.4 1.3 1.3 1.6 2.2 10.2 8.1 8.5 60℃/4 hours mm 2.2 1.9 0.9 1.1 2.3 9.9 10.1 9.2 60℃/10 hours mm 0 0.5 0.5 0.8 1.7 5.2 6.1 4.9 85℃/4 hours mm 0 0 0 0 0 1.1 1.0 0.3 Optical properties 45°C/24 hours - A A A A A A A A 60℃/4 hours - A A A A A A A A 60℃/10 hours - A A A A A A A A 85℃/4 hours - B B B B B B B B

As can be seen from Table 2, in the examples with a storage elasticity coefficient of 4.1 GPa or less, the amount of curling was suppressed under any of the conditions of 45°C for 24 hours, 60°C for 4 hours, and 60°C for 10 hours, and Changes in optical characteristics are also suppressed. In addition, under the condition of 85°C for 4 hours, although the amount of curl was small in the Examples and Comparative Examples, a change in optical characteristics was observed.

All the documents, patent applications, and technical specifications described in this specification are to the same extent as the case where each document, patent application, and technical specifications are specifically and separately described and incorporated by reference, and are incorporated into this specification by reference middle.

10: Wavelength conversion member 11: Wavelength conversion layer 12A, 12B: Cladding material 20: Backlight unit 21: Light source 22: Light guide plate 23: Retroreflective member 24: Reflective plate 30: Liquid crystal display device 31: Liquid crystal cell unit 32 : Liquid crystal cell 33A, 33B: Polarizing plate L _B : Blue light L _G : Green light L _R : Red light L _W : White light

Fig. 1 is a schematic cross-sectional view showing an example of a schematic configuration of a wavelength conversion member. Fig. 2 is a diagram showing an example of a schematic configuration of a backlight unit. Fig. 3 is a diagram showing an example of a schematic configuration of a liquid crystal display device.

10: Wavelength conversion component

11: Wavelength conversion layer

12A, 12B: Cladding material

Claims (8)

A wavelength conversion member having a wavelength conversion layer containing a phosphor, and when measured with a dynamic viscoelasticity measuring device under the conditions of a frequency of 10 Hz and a temperature of 30°C, the storage elastic coefficient of the wavelength conversion member is 4.1 GPa the following. The wavelength conversion member according to claim 1, wherein the value measured by the following method is 6.0 mm or more: On a test bench, the wavelength conversion member processed into a rectangle with a width of 20 mm was arranged so as to protrude from the test bench to the outside by 10 cm in length, and the tip portion of the wavelength conversion member drooping due to its own weight was measured. The distance between the height and the height of the reference surface of the test bench. The wavelength conversion member according to claim 1 or 2, wherein the phosphor includes a quantum dot phosphor. The wavelength conversion member according to claim 3, wherein the quantum dot phosphor includes at least one of Cd and In. The wavelength conversion member according to any one of claims 1 to 4, wherein the wavelength conversion layer includes a cured product of a resin composition, The resin composition contains: The phosphor; Thiol compound At least one selected from the group consisting of (meth)acrylic compounds and (meth)allyl compounds; and Photopolymerization initiator. The wavelength conversion member according to any one of claims 1 to 5, which is formed in a roll shape. A backlight unit includes the wavelength conversion member according to any one of claim 1 to claim 5, and a light source. An image display device including the backlight unit according to claim 7.

Images