WO2022014653A1

WO2022014653A1 - Wavelength conversion member, backlight unit, image display device, production method for wavelength conversion member, and inorganic phosphor processing liquid

Info

Publication number: WO2022014653A1
Application number: PCT/JP2021/026524
Authority: WO
Inventors: 紀一福原; 重昭舟生
Original assignee: 昭和電工マテリアルズ株式会社
Priority date: 2020-07-15
Filing date: 2021-07-14
Publication date: 2022-01-20
Also published as: WO2022013983A1

Abstract

This wavelength conversion member contains inorganic phosphors and a resin cured product containing the organic phosphors. When peak wavelengths of fluorescence spectrums are measured by time-resolved fluorescence spectroscopy for the wavelength conversion member, the absolute value (| λ0–λτ |) of the difference between the peak wavelength λ0 of a fluorescence spectrum of an initial period for at least one type of the organic phosphor and the peak wavelength λτ of a fluorescence spectrum observed after only a fluorescence life τ has elapsed from the observed time point of the fluorescence spectrum of the initial period is 6 nm or less.

Description

Wavelength conversion member, backlight unit, image display device, manufacturing method of wavelength conversion member, and inorganic phosphor processing liquid

The present disclosure relates to a wavelength conversion member, a backlight unit, an image display device, a method for manufacturing the wavelength conversion member, and an inorganic phosphor processing liquid.

In recent years, in the field of image display devices such as liquid crystal displays, it is required to improve the color reproducibility of displays. As a means for improving color reproducibility, a wavelength conversion member containing a quantum dot phosphor is attracting attention as described in Japanese Patent Publication No. 2013-544018 and International Publication No. 2016/0526225.

The wavelength conversion member including the quantum dot phosphor is arranged in the backlight unit of the image display device, for example. When a wavelength conversion member including a quantum dot phosphor that emits red light and a quantum dot phosphor that emits green light is used, when the wavelength conversion member is irradiated with blue light as excitation light, the quantum dot phosphor emits light. White light can be obtained from the red light and green light produced and the blue light transmitted through the wavelength conversion member. With the development of the wavelength conversion member including the quantum dot phosphor, the color reproducibility of the display has been expanded from the conventional NTSC (National Television System Committee) ratio of 72% to the NTSC ratio of 100%.

The wavelength conversion member containing the quantum dot phosphor usually has a cured product obtained by curing the curable composition containing the quantum dot phosphor. The curable composition includes a thermosetting type and a photocurable type, and a photocurable type curable composition is preferably used from the viewpoint of productivity.

Quantum dot phosphors are prone to deterioration due to the effects of water vapor or oxygen. Therefore, when the wavelength conversion member containing the quantum dot phosphor is left in a high temperature and high humidity environment, the quantum dot phosphor may be deteriorated and the emission intensity may be lowered.

In particular, the cured product of the photocurable curable composition containing the quantum dot phosphor has insufficient moisture and heat resistance and heat resistance in a high temperature and high humidity environment, and the quantum dot phosphor deteriorates and the emission intensity decreases. It tends to be easy to do.

In order to suppress a decrease in the emission intensity of the quantum dot phosphor, at least a part of the cured product containing the quantum dot phosphor may be covered with a coating material in the wavelength conversion member containing the quantum dot phosphor. For example, in the case of a film-shaped wavelength conversion member, a barrier film having a barrier property against at least one of oxygen and water may be provided on one side or both sides of a cured product layer containing a quantum dot phosphor. However, even if a covering material such as a barrier film is provided, it may not be possible to sufficiently suppress the decrease in emission intensity.

Further, even when an inorganic phosphor is used in the wavelength conversion member, it is required to suppress a decrease in emission intensity.

The present disclosure has been made in view of the above circumstances, and is a method for manufacturing a wavelength conversion member and a wavelength conversion member, which contains an inorganic phosphor which may be a quantum dot phosphor and has excellent moisture resistance and heat resistance. It is an object of the present invention to provide a backlight unit and an image display device using the above, and an inorganic phosphor processing liquid used for the backlight unit and the image display device.

Specific means for achieving the above-mentioned problems are as follows.
<1> A wavelength conversion member containing a quantum dot phosphor and a cured resin product containing the quantum dot phosphor.
When the peak wavelength of the fluorescence spectrum of the wavelength conversion member was measured by time-resolved fluorescence spectroscopy, the peak wavelength λ0 of the initial fluorescence spectrum and the initial fluorescence spectrum were observed in at least one of the quantum dot phosphors. A wavelength conversion member in which the absolute value (| λ0-λτ |) of the difference between the peak wavelength λτ and the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time point is 6 nm or less.
<2> The wavelength conversion member according to <1>, wherein the quantum dot phosphor contains a compound containing at least one of Cd and In.
<3> A wavelength conversion member containing an inorganic fluorescent substance and a cured resin product containing the inorganic fluorescent substance.
When the peak wavelength of the fluorescence spectrum of the wavelength conversion member was measured by time-resolved fluorescence spectroscopy, the peak wavelength λ0 of the initial fluorescence spectrum and the time point when the initial fluorescence spectrum was observed in at least one of the inorganic phosphors. A wavelength conversion member in which the absolute value (| λ0-λτ |) of the difference between the peak wavelength λτ and the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed is 6 nm or less.
<4> The wavelength conversion member according to any one of <1> to <3>, which is in the form of a film.
<5> The wavelength conversion member according to any one of <1> to <4> for displaying an image.
<6> The wavelength conversion member according to any one of <1> to <5>, which has a covering material that covers at least a part of the cured resin product.
<7> The wavelength conversion member according to <6>, wherein the covering material has a barrier property against at least one of oxygen and water.
<8> A backlight unit including the wavelength conversion member according to any one of <1> to <7> and a light source.
<9> An image display device including the backlight unit according to <8>.
<10> A quantum dot phosphor processing solution A containing a quantum dot phosphor and a curable compound or a curing agent, and the peak wavelength of the fluorescence spectrum of the quantum dot phosphor processing solution A is measured by time-resolved fluorescence spectroscopy. Then, in at least one of the quantum dot phosphors, the peak wavelength λ0 of the initial fluorescence spectrum and the peak wavelength of the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed. The step of preparing the quantum dot phosphor processing liquid A in which the absolute value (| λ0-λτ |) of the difference from λτ is 6 nm or less, and
A step of adding a curable compound and a curing agent to the quantum dot phosphor processing liquid A to prepare a resin composition for wavelength conversion, and a step of preparing the resin composition.
The method for manufacturing a wavelength conversion member according to <1> or <2>.
<11> The step of preparing the quantum dot phosphor processing liquid A is
A step of preparing a plurality of quantum dot phosphor processing solutions containing the quantum dot phosphor and the curable compound or a curing agent and having different concentrations of the quantum dot phosphor.
The step of obtaining | λ0-λτ | for the plurality of quantum dot phosphor processing liquids, and
From the relationship between the concentration of the quantum dot phosphor in the quantum dot phosphor processing liquid and the | λ0-λτ |, the step of obtaining the concentration A of the quantum dot phosphor having | λ0-λτ | of 6 nm or less. When,
A step of preparing a quantum dot phosphor processing liquid A having a concentration A containing the quantum dot phosphor and the curable compound or a curing agent.
The method for manufacturing a wavelength conversion member according to <10>.
<12> An inorganic phosphor processing liquid A containing an inorganic phosphor and a curable compound or a curing agent, and when the peak wavelength of the fluorescence spectrum of the inorganic phosphor processing liquid A is measured by time-resolved fluorescence spectroscopy. , The difference between the peak wavelength λ0 of the initial fluorescence spectrum and the peak wavelength λτ of the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed in at least one of the inorganic phosphors. The step of preparing the inorganic fluorescent material processing liquid A having an absolute value (| λ0-λτ |) of 6 nm or less, and
A step of adding a curable compound and a curing agent to the inorganic phosphor processing liquid A to prepare a resin composition for wavelength conversion, and a step of preparing the resin composition.
The method for manufacturing a wavelength conversion member according to <3>.
<13> The step of preparing the inorganic phosphor processing liquid A is
A step of preparing a plurality of inorganic phosphor processing solutions containing the inorganic phosphor and the curable compound or a curing agent and having different concentrations of the inorganic phosphor.
The step of obtaining | λ0-λτ | for the plurality of inorganic phosphor processing liquids, and
From the relationship between the concentration of the inorganic fluorescent substance in the inorganic phosphor processing liquid and the | λ0-λτ |, the step of obtaining the concentration A of the inorganic fluorescent substance having | λ0-λτ | of 6 nm or less.
A step of preparing the inorganic fluorescent substance processing liquid A having the concentration A containing the inorganic fluorescent substance and the curable compound or the curing agent, and
The method for manufacturing a wavelength conversion member according to <12>.
<14> An inorganic phosphor processing liquid containing an inorganic phosphor and a curable compound or a curing agent, and when the peak wavelength of the fluorescence spectrum of the inorganic phosphor processing liquid is measured by time-resolved fluorescence spectroscopy, the above-mentioned Absolute difference between the peak wavelength λ0 of the initial fluorescence spectrum and the peak wavelength λτ of the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed in at least one of the inorganic phosphors. An inorganic fluorescent substance processing liquid used for preparing a resin composition for wavelength conversion having a value (| λ0-λτ |) of 6 nm or less.

According to the present disclosure, a wavelength conversion member and a method for manufacturing a wavelength conversion member, which contains an inorganic phosphor which may be a quantum dot phosphor and is excellent in moisture and heat resistance and heat resistance, a backlight unit using the same, and an image display. An apparatus and an inorganic fluorescent substance processing liquid used for the apparatus are provided.

It is a figure for demonstrating the fluorescence lifetime τ. It is a schematic cross-sectional view which shows an example of the schematic structure of the wavelength conversion member. It is a figure which shows an example of the schematic structure of the backlight unit. It is a figure which shows an example of the schematic structure of the liquid crystal display device.

Hereinafter, the mode for implementing the present disclosure will be described in detail. However, the present disclosure is not limited to the following embodiments. In the following embodiments, the components (including element steps and the like) are not essential unless otherwise specified. The same applies to the numerical values and their ranges, and does not limit this disclosure.

In the present disclosure, the term "process" includes, in addition to a process independent of other processes, the process as long as the purpose of the process is achieved even if it cannot be clearly distinguished from the other process. ..
In the present disclosure, the numerical range indicated by using "-" includes the numerical values before and after "-" as the minimum value and the maximum value, respectively.
In the numerical range described stepwise in the present disclosure, the upper limit value or the lower limit value described in one numerical range may be replaced with the upper limit value or the lower limit value of the numerical range described in another stepwise description. .. Further, in the numerical range described in the present disclosure, the upper limit value or the lower limit value of the numerical range may be replaced with the value shown in the examples.
In the present disclosure, each component may contain a plurality of applicable substances. When a plurality of substances corresponding to each component are present in the composition, the content or content of each component is the total content or content of the plurality of substances present in the composition unless otherwise specified. Means quantity.
In the present disclosure, the particles corresponding to each component may contain a plurality of types of particles. When a plurality of particles corresponding to each component are present in the composition, the particle size of each component means a value for a mixture of the plurality of particles present in the composition unless otherwise specified.
In the present disclosure, the term "layer" or "membrane" is used only in a part of the region, in addition to the case where the layer or the membrane is formed in the entire region when the region is observed. The case where it is formed is also included.
In the present disclosure, the term "laminated" refers to stacking layers, and two or more layers may be bonded or the two or more layers may be removable.
In the present disclosure, "(meth) acryloyl group" means at least one of an acryloyl group and a methacryloyl group, "(meth) acrylate" means at least one of acrylate and methacrylate, and "(meth) allyl" means allyl. And at least one of metallicyl.

<Wavelength conversion member>
The wavelength conversion member of the present disclosure is a wavelength conversion member containing a quantum dot phosphor and a cured resin containing the quantum dot phosphor, and the fluorescence spectrum of the wavelength conversion member is measured by time-resolved fluorescence spectroscopy. When the peak wavelength is measured, in at least one of the quantum dot phosphors, the peak wavelength λ0 of the initial fluorescence spectrum and the fluorescence observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed. It is a wavelength conversion member having an absolute value (| λ0-λτ |) of the difference from the peak wavelength λτ of the spectrum of 6 nm or less.
Further, the wavelength conversion member of the present disclosure is a wavelength conversion member containing an inorganic phosphor and a cured resin product containing the inorganic phosphor, and the fluorescence spectrum of the wavelength conversion member is measured by time-resolved fluorescence spectroscopy. When the peak wavelength was measured, the peak wavelength λ0 of the initial fluorescence spectrum and the fluorescence spectrum observed after the fluorescence lifetime τ had elapsed from the time when the initial fluorescence spectrum was observed in at least one of the inorganic phosphors. This is a wavelength conversion member having an absolute value (| λ0-λτ |) of difference from the peak wavelength λτ of 6 nm or less.

In the present disclosure, the form in which the cured resin product "includes" a certain component includes a form in which a part of the component is not included in the cured resin product, and when a plurality of the components are present. , Including a form in which some of the components are not included in the cured resin product.

The wavelength conversion member of the present disclosure may be composed of a wavelength conversion layer, or may include other components such as a covering material described later, if necessary.
The wavelength conversion layer according to the present disclosure may be a cured product (cured product of a wavelength conversion resin) of a resin composition for wavelength conversion described later.
As a result of diligent studies, the present inventors have improved the moist heat resistance and heat resistance of the wavelength conversion member when | λ0-λτ | is 6 nm or less in at least one kind of inorganic phosphor which may be a quantum dot phosphor. I found out what to do and completed the present invention. Hereinafter, in the present disclosure, the place described as "quantum dot fluorescent substance" can be read as "inorganic fluorescent substance".
The wavelength conversion member of the present disclosure is suitably used for displaying an image.

In the present disclosure, the peak wavelength λ0 of the initial fluorescence spectrum and the peak wavelength λτ of the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed are both time-resolved fluorescence spectroscopy. Measured by.
In the present disclosure, the "initial fluorescence spectrum" is defined as 0 seconds (reference) at the time when the fluorescence spectrum observed by irradiating the measurement target sample with a pulsed laser used as excitation light has the highest fluorescence intensity. It is defined as the fluorescence spectrum obtained by integrating the fluorescence spectrum intensities up to the elapse of 5 ns.
In the present disclosure, the "fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed" is obtained by integrating the fluorescence spectrum intensities from the time when τ seconds have elapsed from the reference to τ + 5ns. It is defined as the fluorescence spectrum.

In the present disclosure, the "fluorescence lifetime τ" refers to the time required for the intensity of the fluorescence spectrum at 0 seconds to decay to 1 / e. Note that e is the base of the natural logarithm. The time change F (t) of the intensity of the fluorescence spectrum is given by the equation (1).

Here, F ₀ is the intensity of the fluorescence spectrum at t = 0, and τ is the fluorescence lifetime. As shown in FIG. 1, when approximated by a linear equation, the elapsed time T when the number of fluorescent molecules in the excited state becomes 1 / e (about 37%) is the fluorescence lifetime τ. The fluorescence lifetime τ tends to be short when the dielectric constant around the fluorescent molecule is high (hydrophilic), when an energy receptor is present in the vicinity, and the like.

The fluorescence lifetime τ is preferably 6 ns or more, more preferably 10 ns or more, further preferably 15 ns or more, and particularly preferably 20 ns or more. The upper limit of the fluorescence lifetime τ is not particularly limited, and may be 500 ns or less, 200 ns or less, or 100 ns or less.

The "initial fluorescence spectrum", "fluorescence lifetime" and "fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed" are all values measured by time-resolved fluorescence spectroscopy. Say. The measurement by the time-resolved fluorescence spectroscopy can be carried out by, for example, a fluorescence lifetime photometer DeltaFlex manufactured by HORIBA, Ltd. The measurement condition is 25 ° C. The measurement range of the fluorescence spectrum is 450 nm to 750 nm.

Depending on the measuring device, the number of measurements (number of measurement points) may be fixed uniformly and the number of measurement points cannot be changed even if the measurement time is changed. In this case, if the measurement time is made longer than necessary, the number of measurement points per unit time may be reduced and the measurement accuracy of the fluorescence lifetime τ may be lowered. Therefore, the measurement time is preferably set appropriately according to the fluorescence lifetime τ of the fluorescence spectrum, and it is more preferable that the end point of the measurement time is when the peak height of the fluorescence spectrum is attenuated to 10%.
Further, from the viewpoint of measurement accuracy, the number of measurement points is preferably 6 points / ns or more, more preferably 10 points / ns or more, and further preferably 19 points / ns or more.
It is preferable to increase the number of measurement points per unit time as the fluorescence lifetime τ becomes shorter. Specifically, when the fluorescence lifetime τ is about several ns to 20 ns, it is preferably 19 points / ns or more, and when the fluorescence lifetime τ exceeds 20 ns, it is preferably 6 points / ns or more.

In the wavelength conversion member of the present disclosure, | λ0-λτ | of at least one kind of quantum dot phosphor is 6 nm or less, preferably 5 nm or less, and more preferably 4 nm or less. | Λ0-λτ | may be 2 nm or more.
It suffices if | λ0-λτ | | is 6 nm or less in at least one of the quantum dot phosphors contained in the wavelength conversion member, and | λ0-λτ | of all the quantum dot phosphors contained in the wavelength conversion member is 6 nm or less. It is preferable to have.

The cured resin contained in the wavelength conversion member is not particularly limited as long as it includes a quantum dot phosphor. The cured resin may contain an open ring structure, a urethane structure, or a sulfide structure of an epoxy ring, and preferably contains a sulfide structure. The cured resin product containing a sulfide structure may be formed, for example, by a polymerization reaction of a thiol group in a compound containing a thiol group and a carbon-carbon double bond in a compound containing a carbon-carbon double bond. The cured resin product may contain an ester structure.

Examples of the compound containing a carbon-carbon double bond include a (meth) allyl compound containing a (meth) allyl group and a (meth) acrylate compound containing a (meth) acryloyl group. The (meth) acrylate compound tends to have higher polymerization reaction activity than the (meth) allyl compound. The inclusion of the ester structure in the cured resin suggests that the (meth) acrylate compound was used as the compound containing the carbon-carbon double bond. The cured resin product formed by using the (meth) acrylate compound tends to have a higher glass transition temperature than the cured resin product formed by using the (meth) allyl compound.

The ratio (V1) of the peak area (V1) attributed to the SH expansion and contraction vibration to the peak area (V2) attributed to the CH expansion and contraction vibration in the cured resin material measured by the Fourier transform infrared spectrophotometer. / V2) is preferably 0.005 or less, more preferably 0.004 or less, and even more preferably 0.002 or less.
When the cured resin is formed by a polymerization reaction of a thiol group in a compound containing a thiol group and a carbon-carbon double bond in a compound containing a carbon-carbon double bond, the ratio (V1 / V2) is small. That is, it suggests that there are few thiol groups that do not contribute to the polymerization reaction. If the number of thiol groups that do not contribute to the polymerization reaction is small, the glass transition temperature of the cured resin product tends to increase.
The peak area (V1) attributable to SH expansion and contraction vibration and the peak area (V2) attributed to CH expansion and contraction vibration in the cured resin product are measured by the following method using a Fourier transform infrared spectrophotometer. The value that has been set.
Using an FT-IR Spectrometer (PerkinElmer), the surface of the wavelength conversion member to be measured is ATR (Attenuated Total Reflection) analysis. The background measurement is performed with air, and the FT-IR measurement is performed under the condition that the total number of times is 16 times. When the wavelength conversion member has a coating material, the cured product layer of the wavelength conversion member in a state where the coating material is peeled off is subjected to FT-IR measurement.

The cured resin product may include an alicyclic structure. The alicyclic structure contained in the cured resin may be derived from the structure contained in the compound containing a carbon-carbon double bond.
The alicyclic structure contained in the cured resin is not particularly limited, and may be a monocyclic structure or a polycyclic structure such as a bicyclic structure or a tricyclic structure. Specific examples of the alicyclic structure include monocyclic structures such as cyclobutane skeleton, cyclopentane skeleton, and cyclohexane skeleton, tricyclodecane skeleton, cyclohexane skeleton, 1,3-adamantan skeleton, hydrogenated bisphenol A skeleton, and hydrogenated bisphenol. Examples thereof include polycyclic structures such as an F skeleton, a hydrogenated bisphenol S skeleton, and an isobornyl skeleton. Among these, a polycyclic structure is preferable, a tricyclodecane skeleton or an isobornyl skeleton is more preferable, and a tricyclodecane skeleton is further preferable.

The alicyclic structure contained in the cured resin may be one type alone or at least two types, and preferably at least two types.
When at least two types of alicyclic structures are contained in the cured resin, examples of the combination of the alicyclic structures include a combination of a tricyclodecane skeleton and an isobornyl skeleton, a combination of a hydrogenated bisphenol A skeleton and an isobornyl skeleton, and the like. .. Among these, a combination of a tricyclodecane skeleton and an isobornyl skeleton is preferable from the viewpoint of luminous efficiency, brightness and moisture resistance.

The ratio of the polycyclic structure to the alicyclic structure contained in the cured resin is not particularly limited, and the molar standard ratio of the polycyclic structure is preferably 70 mol% to 100 mol%. , 80 mol% to 100 mol%, more preferably 90 mol% to 100 mol%.
When a combination of a tricyclodecane skeleton and an isobornyl skeleton is used as the alicyclic structure, the molar content ratio of the tricyclodecane skeleton and the isobornyl skeleton (tricyclodecane skeleton / isobornyl skeleton) is determined from the viewpoint of moisture and heat resistance. It is preferably 5 to 20, more preferably 5 to 18, and even more preferably 5 to 15.
The ratio of the polycyclic structure to the alicyclic structure and the molar-based content ratio of the tricyclodecane skeleton and the isobornyl skeleton are the contents of the components contained in the wavelength conversion resin composition used for producing the cured resin product. It may be calculated from. For example, the molar-based content ratio of the compound having a tricyclodecane skeleton and the compound having an isobornyl skeleton is consistent with the molar-based content ratio of the tricyclodecane skeleton and the isobornyl skeleton.

When at least two types of alicyclic structures are contained in the cured resin, the SP value of the alicyclic structure having the highest SP value and the SP value of the alicyclic structure having the lowest SP value in the alicyclic structure are used. The difference is preferably 0 to 1.5, more preferably 0 to 1.2, and even more preferably 0 to 1.0 from the viewpoint of emission efficiency and brightness.

The method of calculating the SP value in the present disclosure is described below.
The SP value can be calculated from the formula of ^{δ 2} = ΣE / ΣV based on the Fedors method. Here, δ means the SP value, E means the evaporation energy, and V means the molar volume (references: RT Fedors, Polymer Engineering and Science, 14, 147 (1974), Journal of the Japan Adhesive Society). Vol.22 No.10 (1986)).
Further, the SP value of the alicyclic structure in the present disclosure means an SP value calculated from the atoms or atomic groups constituting the alicyclic structure.
Further, the SP value of the polyfunctional (meth) acrylate compound and the monofunctional (meth) acrylate compound described later means the SP value calculated from the atoms or atomic groups constituting these compounds.

The cured resin product may include a white pigment and other components. Details of the white pigment and other components included in the cured resin product are as described in the section of the resin composition for wavelength conversion described later.
Further, the details of the quantum dot phosphor included in the cured resin product are also described in the section of the resin composition for wavelength conversion described later.

The shape of the wavelength conversion member is not particularly limited, and examples thereof include a film shape and a lens shape. When the wavelength conversion member is applied to a backlight unit described later, the wavelength conversion member is preferably in the form of a film.

When the wavelength conversion member is in the form of a film, the average thickness of the wavelength conversion member is, for example, preferably 50 μm to 400 μm, more preferably 50 μm to 350 μm, and even more preferably 80 μm to 300 μm. When the average thickness of the wavelength conversion member is 50 μm or more, the wavelength conversion efficiency tends to be further improved, and when the average thickness is 400 μm or less, the backlight is applied to the backlight unit described later. There is a tendency for the unit to be thinner.
The average thickness of the film-shaped wavelength conversion member is obtained, for example, as an arithmetic mean value of the thicknesses of any three points measured using a micrometer.

The wavelength conversion member may be one obtained by curing one kind of wavelength conversion resin composition, or may be one obtained by curing two or more kinds of wavelength conversion resin compositions. For example, when the wavelength conversion member is in the form of a film, the wavelength conversion member includes a first cured product layer obtained by curing a wavelength conversion resin composition containing a first quantum dot phosphor and a first quantum dot fluorescence. A second cured product layer obtained by curing a wavelength conversion resin composition containing a second quantum dot phosphor having different emission characteristics from the body may be laminated.
The wavelength conversion resin composition used for manufacturing the wavelength conversion member may be prepared by using a quantum dot phosphor processing liquid described later. By using the quantum dot phosphor processing liquid, the | λ0-λτ | value of the wavelength conversion member tends to be 6 nm or less.

The wavelength conversion member can be obtained by forming a coating film, a molded body, or the like of a wavelength conversion resin composition, performing a drying treatment as necessary, and then irradiating with 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 wavelength conversion resin composition. In one aspect, it is irradiated with ultraviolet rays having a wavelength of 280 nm ~ 400 nm at an irradiation amount of ^{100mJ / cm 2 ~ 5000mJ / cm} 2. Examples of the ultraviolet source 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.

From the viewpoint of further improving the adhesion, the cured resin contained in the wavelength conversion member has a loss tangent (tan δ) of 0.4 to 1. measured under the conditions of a frequency of 10 Hz and a temperature of 25 ° C. by dynamic viscoelasticity measurement. It is preferably 5, more preferably 0.4 to 1.2, and even more preferably 0.4 to 0.6. The loss tangent (tan δ) of the cured resin can be measured using a dynamic viscoelasticity measuring device (for example, Rheometric Scientific, Solid Analyzer RSA-III).

Further, the cured resin product preferably has a glass transition temperature (Tg) of 85 ° C. or higher, more preferably 85 ° C. to 160 ° C., from the viewpoint of further improving adhesion, heat resistance, and moisture heat resistance. , 90 ° C to 120 ° C, more preferably. The glass transition temperature (Tg) of the cured resin product can be measured under the condition of a frequency of 10 Hz using a dynamic viscoelasticity measuring device (for example, Rheometric Scientific, Solid Analyzer RSA-III).

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

The wavelength conversion member of the present disclosure may have a covering material that covers at least a part of the cured resin product. For example, when the cured resin product is in the form of a film, one side or both sides of the cured resin product may be covered with a film-shaped coating material.

The coating material preferably has a barrier property against at least one of oxygen and water, and more preferably has a barrier property against both oxygen and water, from the viewpoint of suppressing a decrease in the luminous efficiency of the quantum dot phosphor. The coating material having a barrier property against at least one of oxygen and water is not particularly limited, and a known coating material such as a barrier film having an inorganic layer can be used.

When the covering material is in the form of a film, the average thickness of the covering material is, for example, preferably 10 μm to 150 μm, more preferably 30 μm to 140 μm, and even more preferably 50 μm to 135 μm. When the average thickness is 10 μm or more, the functions such as barrier property tend to be sufficient, and when the average thickness is 150 μm or less, the decrease in light transmittance tends to be suppressed.
The average thickness of the film-shaped covering material is obtained in the same manner as in the film-shaped wavelength conversion member.

Oxygen permeability of the dressing, for example, is preferably ^{0.5mL / (m 2 · 24h ·} atm) or less, more preferably ^{0.3mL / (m 2 · 24h ·} atm) or less, 0 and more preferably ^{.1mL / (m 2 · 24h ·} atm) or less. The oxygen permeability of the coating material can be measured using an oxygen permeability measuring device (for example, MOCON, OX-TRAN) under the conditions of a temperature of 23 ° C. and a relative humidity of 65%.
Further, the water vapor permeability of the dressing, for example, 5 × ¹⁰ -2 ^g / is preferably (m 2 · 24h · Pa) or ^{^{less, 1 × 10 -2 g / (}} m 2 · 24h · Pa) or less more preferably, even more preferably ^{^{5 × 10 -3 g / (m}} 2 · 24h · Pa) or less. The water vapor permeability of the coating material can be measured using a water vapor permeability measuring device (for example, MOCON, AQUATRAN) under the conditions of a temperature of 40 ° C. and a relative humidity of 90%.

From the viewpoint of further improving the efficiency of light utilization, the wavelength conversion member of the present disclosure preferably has a total light transmittance of 55% or more, more preferably 60% or more, and more preferably 65% or more. More preferred. The total light transmittance of the wavelength conversion member can be measured according to the measurement method of JIS K7361-1: 1997.

Further, the wavelength conversion member of the present disclosure preferably has a haze of 95% or more, more preferably 97% or more, and further preferably 99% or more, from the viewpoint of further improving the efficiency of light utilization. preferable. The haze of the wavelength conversion member can be measured according to the measurement method of JIS K 7136: 2000.

FIG. 2 shows an example of the schematic configuration of the wavelength conversion member. However, the wavelength conversion member of the present disclosure is not limited to the configuration shown in FIG. Further, the sizes of the cured product layer and the covering material in FIG. 2 are conceptual, and the relative relationship between the sizes is not limited to this. In each drawing, the same member may be designated by the same reference numeral, and duplicate description may be omitted.

The wavelength conversion member 10 shown in FIG. 2 has a cured product layer 11 which is a film-shaped cured resin product, and film-shaped coating materials 12A and 12B provided on both sides of the cured product layer 11. The types and average thicknesses of the covering material 12A and the covering material 12B may be the same or different.

The wavelength conversion member having the configuration shown in FIG. 2 can be manufactured by, for example, a known manufacturing method as follows.

First, the wavelength conversion resin composition described later is applied to the surface of a film-like coating material (hereinafter, also referred to as "first coating material") that is continuously conveyed to form a coating film. The method for applying the wavelength conversion resin composition is not particularly limited, and examples thereof include a die coating method, a curtain coating method, an extrusion coating method, a rod coating method, and a roll coating method. The wavelength conversion resin composition may be prepared by using a quantum dot phosphor processing liquid described later.

Next, a film-like covering material (hereinafter, also referred to as "second covering material") that is continuously conveyed is bonded onto the coating film of the wavelength conversion resin composition.

Next, the coating film is cured and a cured product layer is formed by irradiating the active energy rays from the side of the coating material that can transmit the active energy rays among the first coating material and the second coating material. Then, by cutting out to a specified size, a wavelength conversion member having the configuration shown in FIG. 2 can be obtained.

If neither the first coating material nor the second coating material can transmit the active energy ray, the coating film is irradiated with the active energy ray before the second coating material is bonded, and the cured product layer is formed. May be formed.

<Backlight unit>
The backlight unit of the present disclosure includes the wavelength conversion member of the present disclosure described above and a light source.

The backlight unit is preferably a multi-wavelength light source from the viewpoint of improving color reproducibility. In a preferred embodiment, blue light having a emission center wavelength in the wavelength range of 430 nm to 480 nm and having an emission intensity peak having a half width of 100 nm or less, and emission center wavelength in the wavelength range of 520 nm to 560 nm. Back that emits green light having an emission intensity peak having a half-value width of 100 nm or less and red light having an emission center wavelength in the wavelength range of 600 nm to 680 nm and having an emission intensity peak having a half-value width of 100 nm or less. The light unit can be mentioned. In the present disclosure, the full width at half maximum of the emission intensity peak means the full width at half maximum.

From the viewpoint of further improving the 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. 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.

Further, from the viewpoint of further improving the color reproducibility, the half width of each emission intensity peak of the blue light, green light, and red light emitted by the backlight unit is preferably 80 nm or less, preferably 50 nm or less. 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 a emission center wavelength in the wavelength range of 430 nm to 480 nm can be used. Examples of the light source include an LED (Light Emitting Diode) and a laser. When a light source that emits blue light is used, it is preferable that the wavelength conversion member includes at least a quantum dot phosphor R that emits red light and a quantum dot phosphor G that emits green light. Thereby, white light can be obtained by the red light and green light emitted from the wavelength conversion member and the blue light transmitted through the wavelength conversion member.

Further, as the light source of the backlight unit, for example, a light source that emits ultraviolet light having a emission center wavelength in the wavelength range of 300 nm to 430 nm can also be used. Examples of the light source include LEDs and lasers. When a light source that emits ultraviolet light is used, the wavelength conversion member preferably includes a quantum dot phosphor B that is excited by excitation light and emits blue light, together with the quantum dot phosphor R and the quantum dot phosphor G. As a result, white light can be obtained from 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 type or a direct type. The edge light type backlight unit is exemplified by mounting on a monitor such as a personal computer. The direct type backlight unit is exemplified by mounting on a television.

FIG. 3 shows an example of the schematic configuration of the edge light type backlight unit. However, the backlight unit of the present disclosure is not limited to the configuration shown in FIG. Further, the size of the members in FIG. 3 is conceptual, and the relative relationship between the sizes of the members is not limited to this.

The backlight unit 20 shown in FIG. 3 includes a light source 21 for emitting the blue light L _B, a light guide plate 22 to be emitted guiding the blue light L _B emitted from the light source 21, the light guide plate 22 and disposed to face The wavelength conversion member 10 is provided with a retroreflective member 23 arranged to face the light source plate 22 via the wavelength conversion member 10, and a reflector 24 arranged to face the wavelength conversion member 10 via the light guide plate 22. .. Wavelength conversion member 10 emits the red light L _R and the green light L _G part of the blue light L _B as the excitation light, the red light L and _R and the green light L _G, the blue light was not the excitation light L _B is emitted. The red light _{L R,} the green light _{L G,} and the blue light _{L B,} the white light _{L W} is emitted from the retroreflective member 23.

The direct type backlight unit may have a point light source and a diffuser plate for diffusing the light from the point light source and converting it into a surface light source. The wavelength conversion member may be arranged to face the diffuser plate.

<Image display device>
The image display device of the present disclosure includes the backlight unit of the present disclosure described above. The image display device is not particularly limited, and examples thereof include a liquid crystal display device.

FIG. 4 shows an example of the schematic configuration of the liquid crystal display device. However, the liquid crystal display device of the present disclosure is not limited to the configuration shown in FIG. Further, the size of the members in FIG. 4 is conceptual, and the relative relationship between the sizes of the members is not limited to this.

The liquid crystal display device 30 shown in FIG. 4 includes a backlight unit 20 and a liquid crystal cell unit 31 arranged to face the backlight unit 20. The liquid crystal cell unit 31 has a configuration in which the liquid crystal cell 32 is arranged between the polarizing plate 33A and the polarizing plate 33B.

The drive method of the liquid crystal cell 32 is not particularly limited, and is a TN (Twisted Nematic) method, an STN (Super Twisted Nematic) method, a VA (Vertical Birefringence) method, an IPS (In-Plane-Switching) method, an OCB (Optical Birefringence) method. The method and the like can be mentioned.

<Resin composition for wavelength conversion>
The wavelength conversion resin composition of the present disclosure contains a quantum dot phosphor, a curable compound and a curing agent, and may further contain other components, if necessary. Examples of the curable compound include compounds containing two or more carbon-carbon double bonds, epoxy compounds, isocyanate compounds and the like.

When the curable compound contains a compound containing two or more carbon-carbon double bonds, a polyfunctional thiol compound is preferable as the curing agent. In this case, it is preferable that the wavelength conversion resin composition further contains a photopolymerization initiator. Therefore, one aspect of the wavelength conversion resin composition of the present disclosure may include a compound containing two or more carbon-carbon double bonds, a polyfunctional thiol compound, a photopolymerization initiator and a quantum dot phosphor, if necessary. It may further contain other components. The wavelength conversion resin composition of this embodiment is excellent in moisture and heat resistance of the cured product.

When the curable compound contains an epoxy compound, examples of the curing agent include a phenol curing agent, an amine curing agent, an acid anhydride curing agent, and a thiol curing agent.
The wavelength conversion resin composition may be a curable compound in which a compound containing two or more carbon-carbon double bonds and another curable compound other than the compound containing two or more carbon-carbon double bonds are used in combination. good.

Hereinafter, the components that can be contained in the wavelength conversion resin composition of the present disclosure will be described in detail.

(Compound containing two or more carbon-carbon double bonds)
The wavelength conversion resin composition of the present disclosure may contain a compound containing two or more carbon-carbon double bonds. The compound containing two or more carbon-carbon double bonds may contain a polyfunctional (meth) acrylate compound, or may contain a polyfunctional (meth) acrylate compound having an alicyclic structure. The polyfunctional (meth) acrylate compound having an alicyclic structure is a polyfunctional (meth) acrylate compound having an alicyclic structure in the skeleton and having two or more (meth) acryloyl groups in one molecule. When a polyfunctional (meth) acrylate compound having an alicyclic structure is used, the storage stability is excellent, and even when a polyfunctional thiol compound which is said to have a relatively low storage stability is used, the storage stability is excellent. There is a tendency.

The alicyclic structure contained in the polyfunctional (meth) acrylate compound having an alicyclic structure is not particularly limited, and even if it is a monocyclic structure, it may be a bicyclic structure, a tricyclic structure or the like. It may have a polycyclic structure.
Specific examples of the polyfunctional (meth) acrylate compound having an alicyclic structure include tricyclodecanedimethanol di (meth) acrylate, cyclohexanedimethanol di (meth) acrylate, and 1,3-adamantan dimethanol di (meth). Acrylate, hydrogenated bisphenol A (poly) ethoxydi (meth) acrylate, hydrogenated bisphenol A (poly) propoxydi (meth) acrylate, hydrogenated bisphenol F (poly) ethoxydi (meth) acrylate, hydrogenated bisphenol F (poly) propoxide ( Examples thereof include alicyclic (meth) acrylates such as meth) acrylates, hydrogenated bisphenol S (poly) ethoxydi (meth) acrylates, and hydrogenated bisphenol S (poly) propoxydi (meth) acrylates.
From the viewpoint of moisture and heat resistance of the wavelength conversion resin composition, the alicyclic structure contained in the polyfunctional (meth) acrylate compound having an alicyclic structure preferably contains a polycyclic structure, and a tricyclodecane skeleton is formed. It is more preferable to include it. The polyfunctional (meth) acrylate compound having a tricyclodecane skeleton in the alicyclic structure is preferably tricyclodecanedimethanol di (meth) acrylate.

The content of the compound containing two or more carbon-carbon double bonds in the wavelength conversion resin composition is preferably, for example, 40% by mass to 90% by mass with respect to the total amount of the wavelength conversion resin composition. , 50% by mass to 90% by mass, more preferably 60% by mass to 85% by mass. When the content of the compound containing two or more carbon-carbon double bonds is in the above range, the moisture and heat resistance of the cured product tends to be further improved.

The resin composition for wavelength conversion may contain one kind of compound containing two or more carbon-carbon double bonds alone, or may contain two or more kinds of compounds containing two or more carbon-carbon double bonds in combination. May be.

(Thiol compound)
The wavelength conversion resin composition may contain a polyfunctional thiol compound. When the wavelength conversion resin composition contains a polyfunctional thiol compound, an enthiol reaction occurs between the compound containing two or more carbon-carbon double bonds and the polyfunctional thiol compound when the wavelength conversion resin composition is cured. , And the moisture and heat resistance of the cured product tends to be further improved. Further, when the wavelength conversion resin composition contains a polyfunctional thiol compound, the optical properties of the cured product tend to be further improved.

Specific examples of the polyfunctional thiol compound include ethylene glycol bis (3-mercaptopropionate), diethylene glycol bis (3-mercaptopropionate), tetraethylene glycol bis (3-mercaptopropionate), 1,2-. Propropylene glycol bis (3-mercaptopropionate), diethylene glycol bis (3-mercaptobutyrate), 1,4-butanediol bis (3-mercaptopropionate), 1,4-butanediol bis (3-mercaptobutyrate) Rate), 1,8-octanediol bis (3-mercaptopropionate), 1,8-octanediol bis (3-mercaptobutyrate), hexanediol bisthioglycolate, trimethylolpropanetris (3-mercaptopro) Pionate), trimethylolpropanetris (3-mercaptobutyrate), trimethylolpropanetris (3-mercaptoisobutyrate), trimethylolpropanetris (2-mercaptoisobutyrate), trimethylolpropanetristhioglycolate, Tris-[(3-mercaptopropionyloxy) -ethyl] -isocyanurate, trimethylolethanetris (3-mercaptobutyrate), pentaerythritol tetrakis (3-mercaptopropionate), pentaerythritol tetrakis (3-mercaptobutyrate) ), Pentaerythritol tetrakis (3-mercaptoisobutyrate), pentaerythritol tetrakis (2-mercaptoisobutyrate), dipentaerythritol hexakiss (3-mercaptopropionate), dipentaerythritol hexakis (2-mercaptopro) Pionate), Dipentaerythritol Hexakis (3-mercaptobutyrate), Dipentaerythritol Hexakis (3-Mercaptoisobutyrate), Dipentaerythritol Hexakis (2-Mercaptoisobutyrate), Pentaerythritol Tetrakissthioglycolate Examples thereof include rate, dipentaerythritol hexakissthioglycolate and the like.

Further, the polyfunctional thiol compound may be in the state of a thioether oligomer previously reacted with the polyfunctional (meth) acrylate compound.

The thioether oligomer can be obtained by addition polymerization of a polyfunctional thiol compound and a polyfunctional (meth) acrylate compound in the presence of a polymerization initiator. When the thioether oligomer is obtained by addition polymerization, the ratio of the equivalent number of thiol groups of the polyfunctional thiol compound to the equivalent number of (meth) acryloyl groups of the polyfunctional (meth) acrylate compound as a raw material (the number of equivalents of thiol groups / (meth). ) The equivalent number of acryloyl groups) is, for example, preferably 3.0 to 3.3, more preferably 3.0 to 3.2, and further preferably 3.05 to 3.15. preferable.

The weight average molecular weight of the thioether oligomer is, for example, preferably 3000 to 10000, more preferably 3000 to 8000, and even more preferably 4000 to 6000.
The weight average molecular weight of the thioether oligomer is obtained by converting the molecular weight distribution measured by gel permeation chromatography (GPC) using a standard polystyrene calibration curve.

The thiol equivalent of the thioether oligomer is, for example, preferably 200 g / eq to 400 g / eq, more preferably 250 g / eq to 350 g / eq, and further preferably 250 g / eq to 270 g / eq. preferable.

The thiol equivalent of the thioether oligomer can be measured by the following iodine titration method.
Weigh accurately 0.2 g of the measurement sample, and add 20 mL of chloroform to make a sample solution. As a starch indicator, 0.275 g of soluble starch dissolved in 30 g of pure water is used, 20 mL of pure water, 10 mL of isopropyl alcohol, and 1 mL of starch indicator are added, and the mixture is stirred with a stirrer. The iodine solution is added dropwise, and the point at which the chloroform layer turns green is defined as the end point. At this time, the value given by the following formula is taken as the thiol equivalent of the measurement sample.
Equivalent thiol (g / eq) = mass of measurement sample (g) x 10000 / titration of iodine solution (mL) x factor of iodine solution

The wavelength conversion resin composition may contain a monofunctional thiol compound having one thiol group in one molecule.

Specific examples of the monofunctional thiol compound include hexanethiol, 1-heptanethiol, 1-octanethiol, 1-nonanthiol, 1-decanethiol, 3-mercaptopropionic acid, methyl mercaptopropionate, methoxybutyl mercaptopropionate, and the like. Examples thereof include octyl mercaptopropionate, tridecyl mercaptopropionate, 2-ethylhexyl-3-mercaptopropionate, n-octyl-3-mercaptopropionate and the like.

The content of the thiol compound (total of the polyfunctional thiol compound and the monofunctional thiol compound used as needed) in the wavelength conversion resin composition is, for example, 5% by mass with respect to the total amount of the wavelength conversion resin composition. It is preferably% to 50% by mass, more preferably 5% by mass to 40% by mass, further preferably 10% by mass to 30% by mass, and further preferably 15% by mass to 27% by mass. Especially preferable. In this case, due to the enthiol reaction with the polyfunctional (meth) acrylate compound, the cured product tends to form a more dense crosslinked structure, and the moisture resistance and heat resistance tend to be further improved.
The mass-based ratio of the polyfunctional thiol compound to the total of the polyfunctional thiol compound and the monofunctional thiol compound used as needed is preferably 60% by mass to 100% by mass, preferably 70% by mass to 100% by mass. Is more preferable, and 80% by mass to 100% by mass is further preferable.

The mass-based content ratio of the polyfunctional (meth) acrylate compound to the polyfunctional thiol compound (polyfunctional (meth) acrylate compound / polyfunctional thiol compound) is preferably 0.5 to 10, preferably 0.5 to 10. It is more preferably 8.0, and even more preferably 0.5 to 6.0.

(Photopolymerization initiator)
The wavelength conversion resin composition may contain a photopolymerization initiator. The photopolymerization initiator is not particularly limited, and specific 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-dimethylamino-1- (4-morpholinophenyl) -butanone-1, and so on. 2-Methyl-1- [4- (Methylthio) Phenyl] -2-morpholino-propanone-1, 4,4'-bis (dimethylamino) benzophenone (also referred to as "Michler ketone"), 4,4'-bis (Diethylamino) benzophenone, 4-methoxy-4'-dimethylaminobenzophenone, 1-hydroxycyclohexylphenylketone, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropane-1-one, 1- (4- (4-) (2-Hydroxyethoxy) -phenyl) -2-hydroxy-2-methyl-1-propane-1-one, 2-hydroxy-2-methyl-1-phenylpropan-1-one and other aromatic ketone compounds; alkyl Kinone compounds such as anthraquinone and phenanthrenquinone; 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-Phenylphenyl) -4,5-diphenylimidazole dimer, 2,4-di (p-methoxyphenyl) -5-phenylimidazole dimer, 2- (2,4-dimethoxyphenyl)- 2,4,5-Triarylimidazole dimer such as 4,5-diphenylimidazole dimer; aclysine derivative such as 9-phenylaclydin, 1,7- (9,9'-acrydinyl) heptane; 1,2 -Octanedione 1- [4- (Phenylthio) -2- (O-benzoyloxime)], Etanone 1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazole-3-yl] -1- Oxyme ester compounds such as (O-acetyloxime); coumarin compounds such as 7-diethylamino-4-methylcoumarin; thioxanthone compounds such as 2,4-diethylthioxanthone; 2,4,6-trimethylbenzoyldiphenylphosphenyl oxide, 2, 4,6-trimethylbenzoylphenyl Acylphosphine oxide compounds such as luethoxyphosphine oxide; and the like. The wavelength conversion resin composition may contain one kind of photopolymerization initiator alone, or may contain two or more kinds of photopolymerization initiators in combination.

As the photopolymerization initiator, at least one selected from the group consisting of an acylphosphine oxide compound, an aromatic ketone compound, and an oxime ester compound is preferable from the viewpoint of curability, and the acylphosphine oxide compound and the aromatic ketone compound are selected. At least one selected from the above group is more preferable, and an acylphosphine oxide compound is further preferable.

The content of the photopolymerization initiator in the wavelength conversion resin composition is preferably, for example, 0.1% by mass to 5% by mass, preferably 0.1% by mass, based on the total amount of the wavelength conversion resin composition. It is more preferably% to 3% by mass, and even more preferably 0.5% by mass to 1.5% by mass. When the content of the photopolymerization initiator is 0.1% by mass or more, the sensitivity of the resin composition for wavelength conversion tends to be sufficient, and the content of the photopolymerization initiator is 5% by mass or less. In addition, the influence of the cured product of the wavelength conversion resin composition on the hue and the deterioration of the storage stability tend to be suppressed.

(Inorganic phosphor)
The wavelength conversion resin composition may contain an inorganic phosphor. The inorganic phosphor is not particularly limited, and Y ₃ O ₃ : Eu, YVO ₄ : Eu, Y ₂ O ₂ : Eu, 3.5 MgO / 0.5 MgF ₂ , GeO ₂ : Mn, (Y · Cd) BO ₂ : Eu, K ₂ SiF ₆ : ^{Red light emitting inorganic phosphor such as Mn 4+} , 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, SiAlON and other green light emitting inorganic phosphors, ZnS: Ag, GaWO ₄ , Examples thereof include blue light emitting inorganic phosphors such as Y ₂ SiO ₆ : Ce, ZnS: Ag · Ga · Cl, Ca ₂ B ₄ OCl: Eu ²⁺ , BaMgAl ₄ O ₃ : Eu ^2+.

(Quantum dot phosphor)
The wavelength conversion resin composition may contain a quantum dot phosphor. The quantum dot phosphor is not particularly limited, and examples thereof include particles containing at least one selected from the group consisting of II-VI group compounds, III-V group compounds, IV-VI group compounds, and IV group compounds. Examples of the quantum dot phosphor include particles of a compound having a perovskite-type crystal structure, but may be other than a compound having a perovskite-type crystal structure, and from the viewpoint of emission efficiency, include at least one of Cd and In. It preferably contains a compound.

Specific examples of the II-VI group compounds include CdSe, CdTe, CdS, ZnS, ZnSe, ZnTe, ZnO, HgS, HgSe, HgTe, CdSeS, CdSeTe, CdSTe, ZnSeS, ZnSeTe, ZnSTe, HgSeS, ZnS. , CdZnSe, CdZnTe, CdHgS, CdHgSe, CdHgTe, HgZnS, HgZnSe, HgZnTe, CdZnSeS, CdZnSeTe, CdZnSTe, CdHgSeS, CdHgSeTe, CdHgSne
Specific examples of the III-V group compounds include GaN, GaP, GaAs, GaSb, AlN, AlP, AlAs, AlSb, InN, InP, InAs, InSb, PLCAP, PLGAs, VMwareSb, GaPAs, GaPSb, AlNP, AlNAs, AlNSb. , AlPAs, AlPSb, InNP, InNAs, InNSb, InPAs, InPSb, GaAlNP, GaAlNAs, GaAlNSb, GaAlPAs, GaAlPSb, GaInNP, GaInNAs, GaInNSb, GaInPAs, GaInNSb, GaInPAs, GaInPSb, In
Specific examples of the IV-VI group compounds include SnS, SnSe, SnTe, PbS, PbSe, PbTe, SnSeS, SnSeTe, SnSTe, PbSeS, PbSeTe, PbSTe, SnPbS, SnPbSe, SnPbSne, SnPbSe, SnPbSn ..
Specific examples of the Group IV compound include Si, Ge, SiC, SiGe and the like.

The quantum dot phosphor preferably has 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, it is possible to further improve the quantum efficiency of the quantum dot phosphor. 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.

Further, the quantum dot phosphor may have a so-called core multi-shell structure in which the shell has a multi-layer structure. By stacking one layer or two or more shells with a narrow bandgap on a core with a wide bandgap, and further stacking a shell with a wide bandgap on this shell, the quantum efficiency of the quantum dot phosphor can be further improved. Is possible.

The wavelength conversion resin composition may contain one type of quantum dot phosphor alone, or may contain two or more types of quantum dot phosphors in combination. Examples of a mode in which two or more types of quantum dot phosphors are contained in combination include a mode in which two or more types of quantum dot phosphors having different components but the same average particle size are contained, and a mode in which components having different average particle sizes are the same. Examples thereof include an embodiment containing two or more types of quantum dot phosphors, and an embodiment containing two or more types of quantum dot phosphors having different components and average particle diameters. The emission center wavelength of the quantum dot phosphor can be changed by changing at least one of the component and the average particle diameter of the quantum dot phosphor.

For example, the wavelength conversion resin composition includes a quantum dot phosphor G having a emission center wavelength in the green wavelength range of 520 nm to 560 nm and a quantum dot phosphor R having a emission center wavelength in the red wavelength range of 600 nm to 680 nm. And may be contained. When the cured product of the wavelength conversion resin composition containing the quantum dot phosphor G and the quantum dot phosphor R is irradiated with excitation light in the blue wavelength range of 430 nm to 480 nm, the quantum dot phosphor G and the quantum dots are irradiated. Green light and red light are emitted from the phosphor R, respectively. 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 cured product.

The quantum dot phosphor may be used in the state of a quantum dot phosphor dispersion liquid dispersed in a dispersion medium. Examples of the dispersion medium for dispersing the quantum dot phosphor include various solvents and monofunctional (meth) acrylate compounds.
Examples of the solvent that can be used as the dispersion medium include water, acetone, ethyl acetate, toluene, n-hexane and the like.
The monofunctional (meth) acrylate compound that can be used as a dispersion medium is not particularly limited as long as it is a liquid at room temperature (25 ° C.), and examples thereof include a monofunctional (meth) acrylate compound having an alicyclic structure. It may be a monofunctional (meth) acrylate compound having. The alicyclic structure contained in the monofunctional (meth) acrylate compound is not particularly limited, and even if it is a monocyclic structure, it is a polycyclic structure such as a bicyclic structure or a tricyclic structure. You may. Specific examples of the monofunctional (meth) acrylate compound include isobornyl (meth) acrylate and dicyclopentanyl (meth) acrylate.
Among these, the dispersion medium is preferably a monofunctional (meth) acrylate compound, and has an alicyclic structure, from the viewpoint of eliminating the need for a step of volatilizing the dispersion medium when curing the wavelength conversion resin composition. It is more preferably a monofunctional (meth) acrylate compound having a polycyclic structure, further preferably a monofunctional (meth) acrylate compound having a polycyclic structure, and isobornyl (meth) acrylate and dicyclopentanyl (meth) acrylate. Is particularly preferable, and isobornyl (meth) acrylate is extremely preferable.

When a monofunctional (meth) acrylate compound is used as the dispersion medium, the SP value of the compound having the highest SP value and the compound having the lowest SP value among the polyfunctional (meth) acrylate compound and the monofunctional (meth) acrylate compound are used. The difference from the SP value is preferably 0 to 1.5, more preferably 0 to 1.3, and even more preferably 0 to 1.1 from the viewpoint of luminous efficiency and brightness.
The method for calculating the SP value of the polyfunctional (meth) acrylate compound and the monofunctional (meth) acrylate compound is as described above.

When a monofunctional (meth) acrylate compound is used as the dispersion medium, the content ratio based on the mass of the monofunctional (meth) acrylate compound and the polyfunctional (meth) acrylate compound (monofunctional (meth) acrylate compound / polyfunctional (meth)). The acrylate compound) is preferably 0.01 to 0.30, more preferably 0.02 to 0.20, and even more preferably 0.05 to 0.20.

When a monofunctional (meth) acrylate compound is used as the dispersion medium, the polyfunctional (meth) acrylate compound is tricyclo as a combination of the monofunctional (meth) acrylate compound and the polyfunctional (meth) acrylate compound from the viewpoint of moisture and heat resistance. It is preferable that the compound having a decane skeleton is contained and the monofunctional (meth) acrylate compound contains a compound having an isobornyl skeleton.
The molar content ratio of the compound having a tricyclodecane skeleton and the compound having an isobornyl skeleton (compound having a tricyclodecane skeleton / compound having an isobornyl skeleton) may be 5 to 20 from the viewpoint of moisture and heat resistance. It is preferably 5 to 18, more preferably 5 to 15, and even more preferably 5 to 15.

The mass-based ratio of the quantum dot phosphor to the quantum dot phosphor dispersion is preferably 1% by mass to 30% by mass, more preferably 1% by mass to 20% by mass, and 1% by mass to. It is more preferably 10% by mass.

The content of the quantum dot phosphor dispersion liquid in the resin composition for wavelength conversion is wavelength conversion when the mass-based ratio of the quantum dot phosphor to the quantum dot phosphor dispersion liquid is 1% by mass to 20% by mass. For example, it is preferably 1% by mass to 10% by mass, more preferably 4% by mass to 10% by mass, and 4% by mass to 7% by mass with respect to the total amount of the resin composition for use. More preferred.
Further, the content of the quantum dot phosphor in the wavelength conversion resin composition is preferably, for example, 0.01% by mass to 1.0% by mass, based on the total amount of the wavelength conversion resin composition. It is more preferably 0.05% by mass to 0.5% by mass, and further preferably 0.1% by mass to 0.5% by mass. When the content of the quantum dot phosphor is 0.01% by mass or more, sufficient emission intensity tends to be obtained when the cured product is irradiated with the excitation light, and the content of the quantum dot phosphor is 1.0. When it is mass% or less, the aggregation of the quantum dot phosphor tends to be suppressed.

(Liquid medium)
The wavelength conversion resin composition preferably does not contain a liquid medium or has a liquid medium content of 0.5% by mass or less. The liquid medium means a medium 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-n-pentyl ketone, methyl-n-hexyl ketone, diethyl ketone, and the like. Ketone solvents such as dipropylketone, diisobutylketone, trimethylnonanone, cyclohexanone, cyclopentanone, methylcyclohexanone, 2,4-pentandione, acetonylacetone; diethyl ether, methyl ethyl ether, methyl-n-propyl ether, diisopropyl Ether, tetrahydrofuran, methyl tetrahydrofuran, 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, 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, tri Ethylene glycol 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 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 ether, dipropylene glycol methyl-n-butyl ether, dipropi Lenglycol di-n-propyl ether, dipropylene glycol di-n-butyl ether, dipropylene glycol methyl-n-hexyl ether, tripropylene glycol dimethyl ether, tripropylene glycol diethyl 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 diethyl ether, tetrapropylene glycol methyl ethyl ether, tetrapropylene glycol methyl-n-butyl ether , Ether solvent such as tetrapropylene glycol methyl-n-hexyl ether; carbonate solvent such as propylene carbonate, ethylene carbonate, diethyl carbonate; methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, Sec-butyl acetate, n-pentyl acetate, sec-pentyl acetate, 3-methoxybutyl acetate, methylpentyl acetate, 2-ethylbutyl acetate, 2-ethylhexyl acetate, 2- (2-butoxyethoxy) ethyl acetate, benzyl acetate, acetate Cyclohexyl, methyl cyclohexyl acetate, nonyl acetate, methyl acetoacetate, ethyl acetoacetate, diethylene glycol methyl ether acetate, diethylene glycol monoethyl ether acetate, dipropylene glycol methyl ether acetate, dipropylene glycol ethyl acetate ether, glycol diacetate, methoxytriethylene acetate Glycol, ethyl propionate, n-butyl propionate, isoamyl propionate, diethyl oxalate, di-n-butyl oxalate, methyl lactate, ethyl lactate, n-butyl lactate, n-amyl lactate, ethylene glycol methyl ether propio Nate, ethylene glycol ethyl ether propionate, ethylene glycol methyl ether acetate, ethylene glycol ethyl ether acetate, propylene glycol methyl ether acetate, propylene glycol ethyl ether acetate, propylene glycol propyl ether acetate, γ-butyrolactone, γ-valerolactone, etc. Ester solvent; acetonitrile, N-methylpyrrolidinone, N-ethylpyrrolidinone, N-p Aprotonic polar solvents such as ropylpyrrolidinone, N-butylpyrrolidinone, N-hexylpyrrolidinone, N-cyclohexylpyrrolidinone, N, N-dimethylformamide, N, N-dimethylacetamide, dimethylsulfoxide; methanol, ethanol, n-propanol , Isopropanol, n-butanol, isobutanol, sec-butanol, t-butanol, n-pentanol, isopentanol, 2-methylbutanol, sec-pentanol, t-pentanol, 3-methoxybutanol, n-hexanol , 2-Methylpentanol, sec-hexanol, 2-ethylbutanol, sec-heptanol, n-octanol, 2-ethylhexanol, sec-octanol, n-nonyl alcohol, n-decanol, sec-undecyl alcohol, trimethylnonyl Alcohol, sec-tetradecyl alcohol, sec-heptadecyl alcohol, cyclohexanol, methylcyclohexanol, benzyl alcohol, ethylene glycol, 1,2-propylene glycol, 1,3-butylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol , Alcohol solvents such as tripropylene glycol; 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, Glycol monoether solvents such as triethylene glycol monoethyl ether, tetraethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, tripropylene glycol monomethyl ether; terpinene, terpineol, Telpen solvents such as Milsen, Aloocimen, Limonen, Dipentene, Pinen, Carvone, Osimen, Ferrandrene; Straight silicone oils such as dimethyl silicone oil, Methylphenyl silicone oil, Methylhydrogen silicone oil; Amino-modified silicone oil, Epylene-modified silicone oil , Propylene glycol modified silicone oil, Carbinol modified silicone Acid oil, mercapto-modified silicone oil, heterogeneous functional group-modified silicone oil, polyether-modified silicone oil, methylstyryl-modified silicone oil, hydrophilic special-modified silicone oil, higher alkoxy-modified silicone oil, higher fatty acid-modified silicone oil, fluorine-modified silicone oil, etc. Modified silicone oils; butanoic acid, pentanoic acid, hexanoic acid, heptanic acid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid, dodecanoic acid, tridecanoic acid, tetradecanoic acid, pentadecanoic acid, hexadecanoic acid, heptadecanoic acid, octadecanoic acid, Saturated aliphatic monocarboxylic acids having 4 or more carbon atoms such as nonadecanic acid, icosanoic acid, and eicosenoic acid; unsaturated aliphatic monocarboxylic acids having 8 or more carbon atoms such as oleic acid, elladic acid, linoleic acid, and palmitoleic acid; Can be mentioned. When the wavelength conversion resin composition contains a liquid medium, one type of liquid medium may be contained alone, or two or more types of liquid media may be contained in combination.

(White pigment)
The wavelength conversion resin composition may further contain a white pigment.
Specific examples of the white pigment include titanium oxide, barium sulfate, zinc oxide, calcium carbonate and the like. Among these, titanium oxide is preferable from the viewpoint of light scattering efficiency.
When the wavelength conversion resin composition contains titanium oxide as a white pigment, the titanium oxide may be rutile-type titanium oxide or anatase-type titanium oxide, and rutile-type titanium oxide is preferable.

The average particle size of the white pigment is preferably 0.1 μm to 1 μm, more preferably 0.2 μm to 0.8 μm, and even more preferably 0.2 μm to 0.5 μm.
In the present disclosure, the average particle size of the white pigment can be measured as follows.
The white pigment extracted from the wavelength conversion resin composition is dispersed in purified water containing a surfactant to obtain a dispersion liquid. In the volume-based particle size distribution measured by a laser diffraction type particle size distribution measuring device (for example, Shimadzu Corporation, SALD-3000J) using this dispersion, the value when the integration from the small diameter side is 50% (for example). The median diameter (D50)) is defined as the average particle size of the white pigment. Examples of the method of extracting the white pigment from the wavelength conversion resin composition include a method of diluting the wavelength conversion resin composition with a liquid medium and precipitating the white pigment by centrifugation or the like to distribute the white pigment.
For the average particle size of the white pigment contained in the cured resin product, the equivalent circle diameter (geometric mean of major axis and minor axis) was calculated for 50 particles by observing the particles using a scanning electron microscope. It can be calculated as the arithmetic mean value.

When the wavelength conversion resin composition contains a white pigment, the white pigment has an organic material layer containing an organic substance on at least a part of the surface thereof from the viewpoint of suppressing the aggregation of the white pigment in the wavelength conversion resin composition. It is preferable to have. The organic substances contained in the organic substance layer include organic silane, organosiloxane, fluorosilane, organic phosphonate, organic phosphoric acid compound, organic phosphinate, organic sulfonic acid compound, carboxylic acid, carboxylic acid ester, carboxylic acid derivative, amide, and hydrocarbon. Examples thereof include waxes, polyolefins, copolymers of polyolefins, polyols, derivatives of polyols, alkanolamines, derivatives of alkanolamines, organic dispersants and the like.
The organic substance contained in the organic substance layer preferably contains a polyol, an organic silane, or the like, and more preferably contains at least one of the polyol or the organic silane.
Specific examples of the organic silane include octyltriethoxysilane, nonyltriethoxysilane, decyltriethoxysilane, dodecyltriethoxysilane, tridecyltriethoxysilane, tetradecyltriethoxysilane, pentadecyltriethoxysilane, and hexadecyltriethoxysilane. Examples thereof include silane, heptadecyltriethoxysilane, and octadecyltriethoxysilane.
Specific examples of the organosiloxane include polydimethylsiloxane (PDMS) terminated with a trimethylsilyl functional group, polymethylhydrosiloxane (PMHS), polysiloxane induced by functionalization of PMHS with an olefin (by hydrosilylation), and the like. Be done.
Specific examples of organic phosphonates include n-octylphosphonic acid and its esters, n-decylphosphonic acid and its esters, 2-ethylhexylphosphonic acid and its esters, and camphyl phosphonic acid and its esters.
Specific examples of the organic phosphoric acid compound include organic acidic phosphate, organic pyrophosphate, organic polyphosphate, organic metaphosphate, salts thereof and the like.
Specific examples of the organic phosphinate include, for example, n-hexylphosphinic acid and its ester, n-octylphosphinic acid and its ester, di-n-hexylphosphinic acid and its ester, and di-n-octylphosphinic acid and its ester. Can be mentioned.
Specific examples of the organic sulfonic acid compound include alkyl sulfonic acids such as hexyl sulfonic acid, octyl sulfonic acid, and 2-ethylhexyl sulfonic acid, these alkyl sulfonic acids, metal ions such as sodium, calcium, magnesium, aluminum, and titanium, and ammonium. Examples thereof include salts with ions, organic ammonium ions such as triethanolamine, and the like.
Specific examples of the carboxylic acid include maleic acid, malonic acid, fumaric acid, benzoic acid, phthalic acid, stearic acid, oleic acid, linoleic acid and the like.
Specific examples of the carboxylic acid ester include the above carboxylic acid, ethylene glycol, propylene glycol, trimethylolpropane, diethanolamine, triethanolamine, glycerol, hexanetriol, erythritol, mannitol, sorbitol, pentaerythritol, bisphenol A, hydroquinone, and flo. Examples thereof include esters and partial esters produced by reaction with a hydroxy compound such as loglucinol.
Specific examples of the amide include stearic acid amide, oleic acid amide, erucic acid amide and the like.
Specific examples of the polyolefin and its copolymer include a copolymer of polyethylene, polypropylene, ethylene and one or more compounds selected from propylene, butylene, vinyl acetate, acrylate, acrylamide and the like.
Specific examples of the polyol include glycerol, trimethylolethane, trimethylolpropane and the like.
Specific examples of the alkanolamine include diethanolamine and triethanolamine.
Specific examples of the organic dispersant include high molecular weight organic dispersants having functional groups such as citric acid, polyacrylic acid, polymethacrylic acid, anionic, cationic, bipolar and nonionic functional groups.
When the aggregation of the white pigment in the wavelength conversion resin composition is suppressed, the dispersibility of the white pigment in the cured resin tends to be improved.

The white pigment may have an oxide layer containing a metal oxide or the like on at least a part of the surface thereof. Examples of the metal oxide contained in the oxide layer include silicon dioxide, aluminum oxide, zirconia, phosphoria, and boria. The oxide layer may be one layer or two or more layers. When the white pigment has two oxide layers, it preferably contains a first oxide layer containing silicon dioxide and a second oxide layer containing aluminum oxide.
When the white pigment has an oxide layer, the dispersibility of the white pigment in the cured resin product containing the alicyclic structure and the sulfide structure tends to be improved.

The white pigment may have an organic substance layer and an oxide layer. In this case, it is preferable that the oxide layer and the organic substance layer are provided on the surface of the white pigment in the order of the oxide layer and the organic substance layer. When the white pigment has an organic layer and two oxide layers, the first oxide layer containing silicon dioxide, the second oxide layer containing aluminum oxide and the organic layer are placed on the surface of the white pigment. It is preferable that the monooxide layer, the second oxide layer and the organic substance layer are provided in this order.

When the wavelength conversion resin composition contains a white pigment, the content of the white pigment in the wavelength conversion resin composition is, for example, 0.1% by mass to 1 with respect to the total amount of the wavelength conversion resin composition. It is preferably 0.0% by mass, more preferably 0.2% by mass to 1.0% by mass, and even more preferably 0.3% by mass to 1.0% by mass.

(Other ingredients)
The wavelength conversion resin composition may further contain other components such as a polymerization inhibitor, a silane coupling agent, a surfactant, a adhesion-imparting agent, and an antioxidant. The wavelength conversion resin composition may contain one kind individually or a combination of two or more kinds for each of the other components.
Further, the wavelength conversion resin composition may contain a (meth) allyl compound, if necessary.

(Use of resin composition for wavelength conversion)
The wavelength conversion resin composition can be suitably used for film formation. Further, the wavelength conversion resin composition can be suitably used for forming a wavelength conversion member.

(Method for preparing resin composition for wavelength conversion)
The wavelength conversion resin composition can be prepared by mixing a quantum dot phosphor, a curable compound and a curing agent for forming a cured resin product, and if necessary, other components by a conventional method. The quantum dot phosphor may be mixed in the state of the quantum dot phosphor dispersion liquid.
When preparing the wavelength conversion resin composition, the quantum dot phosphor processing liquid of the present disclosure described later may be used instead of the quantum dot phosphor dispersion liquid.
When preparing a resin composition for wavelength conversion using a quantum dot phosphor processing liquid, a curable compound and a curing agent may be separately added to the quantum dot phosphor processing liquid to prepare a wavelength conversion resin composition. .. For example, a quantum dot phosphor processing solution containing a quantum dot phosphor and a thiol compound is prepared, and a thiol compound is additionally added to the quantum dot phosphor processing solution to prepare a resin composition for wavelength conversion. May be good.

<Quantum dot phosphor processing liquid>
The quantum dot phosphor processing liquid of the present disclosure contains a quantum dot phosphor and a curable compound or a curing agent, and may contain other components as necessary. The "curable compound or curing agent" in the quantum dot phosphor processing liquid is also referred to as a "processing liquid resin component". The processing liquid resin component of the quantum dot phosphor processing liquid is preferably at least a part of the curable compound contained in the wavelength conversion resin composition or at least a part of the curing agent.
When a curable compound, a compound containing two or more carbon-carbon double bonds and a thiol compound are used as the curing agent in the wavelength conversion resin composition, the quantum dot phosphor processing liquid contains the quantum dot phosphor and the thiol compound. It is preferable to do so. The thiol compound may be a monofunctional thiol compound or a polyfunctional thiol compound, and a polyfunctional thiol compound is preferable.

The ratio of the quantum dot phosphor to the processing liquid resin component in the quantum dot phosphor processing liquid is not particularly limited. For example, the quantum dot phosphor dispersion liquid is preferably contained in an amount of 300 parts by mass or less, more preferably 250 parts by mass or less, based on 100 parts by mass of the processing liquid resin component in the quantum dot phosphor processing liquid. It is more preferably contained in an amount of 200 parts by mass or less.
Further, in the quantum dot phosphor processing liquid, it is preferable that the quantum dot phosphor dispersion liquid is contained in an amount of 10 parts by mass or more, and more preferably 50 parts by mass or more, based on 100 parts by mass of the processing liquid resin component. It is more preferably contained in an amount of 80 parts by mass or more.
In the quantum dot phosphor processing liquid, it is preferable to contain 10 parts by mass to 300 parts by mass, and more preferably 50 parts by mass to 250 parts by mass, with respect to 100 parts by mass of the processing liquid resin component. It is preferably contained in an amount of 80 parts by mass to 200 parts by mass, more preferably.
When two or more types of quantum dot phosphor dispersion liquids are used in combination, the ratio of the quantum dot phosphor dispersion liquid to 100 parts by mass of the processing liquid resin component is such that the ratio of the quantum dot phosphor dispersion liquid to 100 parts by mass of the processing liquid resin component is two or more types of quantum dot phosphors. The ratio of the total amount of the dispersion liquid is preferably in the above range.

When the quantum dot phosphor processing liquid contains a thiol compound, the ratio of the quantum dot phosphor to the thiol compound in the quantum dot phosphor processing liquid is not particularly limited. For example, in the quantum dot phosphor processing liquid, the quantum dot phosphor dispersion liquid is preferably contained in an amount of 300 parts by mass or less, more preferably 250 parts by mass or less, and 200 parts by mass with respect to 100 parts by mass of the thiol compound. It is more preferable that the content is less than or equal to a portion.
Further, in the quantum dot phosphor processing liquid, it is preferable that the quantum dot phosphor dispersion liquid is contained in an amount of 10 parts by mass or more, more preferably 50 parts by mass or more, and 80 parts by mass with respect to 100 parts by mass of the thiol compound. It is more preferable to contain it in parts or more.
The quantum dot phosphor processing liquid preferably contains 10 parts by mass to 300 parts by mass, more preferably 50 parts by mass to 250 parts by mass, with respect to 100 parts by mass of the thiol compound. It is more preferable to contain 80 parts by mass to 200 parts by mass.
When two or more types of quantum dot phosphor dispersions are used in combination, the ratio of the quantum dot phosphor dispersion to 100 parts by mass of the thiol compound is the sum of the two or more types of quantum dot phosphor dispersions to 100 parts by mass of the thiol compound. The amount ratio is preferably in the above range.

Further, in the quantum dot phosphor processing liquid, the total amount of the quantum dot phosphor is preferably contained in an amount of 50 parts by mass or less, more preferably 40 parts by mass or less, based on 100 parts by mass of the resin component of the processing liquid. It is more preferably contained in an amount of 20 parts by mass or less. Further, in the quantum dot phosphor processing liquid, the total amount of the quantum dot phosphor is preferably contained in an amount of 1 part by mass or more, more preferably 5 parts by mass or more, based on 100 parts by mass of the resin component of the processing liquid. It is more preferably contained in an amount of 10 parts by mass or more.
The total amount of the quantum dot phosphor is preferably contained in an amount of 1 part by mass to 50 parts by mass, more preferably 5 parts by mass to 40 parts by mass, based on 100 parts by mass of the resin component of the processing liquid in the quantum dot phosphor processing liquid. It is preferably contained in an amount of 10 parts by mass to 20 parts by mass, more preferably 10 parts by mass.

When the quantum dot phosphor processing liquid contains a thiol compound, the total amount of the quantum dot phosphor is preferably 100 parts by mass or less, preferably 50 parts by mass, based on 100 parts by mass of the thiol compound in the quantum dot phosphor processing liquid. It is more preferably contained in an amount of 20 parts by mass or less, and further preferably contained in an amount of 20 parts by mass or less. Further, the total amount of the quantum dot phosphor is preferably contained in an amount of 5 parts by mass or more, and more preferably 10 parts by mass or more, based on 100 parts by mass of the thiol compound in the quantum dot phosphor processing liquid.
The total amount of the quantum dot phosphor is preferably contained in an amount of 5 parts by mass to 100 parts by mass, more preferably 10 parts by mass to 50 parts by mass, based on 100 parts by mass of the thiol compound in the quantum dot phosphor processing liquid. It is more preferably contained in an amount of 10 parts by mass to 20 parts by mass.

The quantum dot phosphor processing liquid may be one in which the above-mentioned quantum dot phosphor dispersion liquid contains a thiol compound and is allowed to elapse for a predetermined period as necessary.

The peak wavelength λ0 of the initial fluorescence spectrum measured by time-resolved fluorescence spectroscopy for the quantum dot phosphor processing solution, and the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed. The absolute value (| λ0-λτ |) of the difference from the peak wavelength λτ of is preferably 6 nm or less, more preferably 5 nm or less, and further preferably 4 nm or less. When the quantum dot phosphor processing liquid contains two or more types of quantum dot phosphors, it is preferable that | λ0-λτ | of at least one of the quantum dot phosphors is 6 nm or less, and the quantum dot phosphor processing liquid is used. It is more preferable that | λ0-λτ | of all the contained quantum dot phosphors is 6 nm or less.

The method for preparing the wavelength conversion resin composition using the quantum dot phosphor processing liquid may include the following steps.
A quantum dot phosphor processing solution A containing a quantum dot phosphor and a curable compound or a curing agent, when the peak wavelength of the fluorescence spectrum of the quantum dot phosphor processing solution A is measured by time-resolved fluorescence spectroscopy. In at least one of the quantum dot phosphors, the peak wavelength λ0 of the initial fluorescence spectrum and the peak wavelength λτ of the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed. A step of preparing a quantum dot phosphor processing liquid A having an absolute difference (| λ0-λτ |) of 6 nm or less.
A step of adding a curable compound and a curing agent to the quantum dot phosphor processing liquid A to prepare a resin composition for wavelength conversion.

In the step of preparing the wavelength conversion resin composition, other components as optional components may be added.

The step of preparing the quantum dot phosphor processing liquid A may include the following steps.
A step of preparing a plurality of quantum dot phosphor processing solutions containing the quantum dot phosphor and the curable compound or a curing agent and having different concentrations of the quantum dot phosphor.
A step of obtaining | λ0-λτ | for the plurality of quantum dot phosphor processing liquids.
From the relationship between the concentration of the quantum dot phosphor in the quantum dot phosphor processing liquid and the | λ0-λτ |, the step of obtaining the concentration A of the quantum dot phosphor having | λ0-λτ | of 6 nm or less. ..
A step of preparing a quantum dot phosphor processing liquid A having a concentration A containing the quantum dot phosphor and the curable compound or a curing agent.

The type of the quantum dot phosphor contained in the quantum dot phosphor processing liquid is not particularly limited, and is preferably a compound containing at least one of Cd and In, and more preferably InP.

<Cursed resin for wavelength conversion>
The wavelength conversion resin cured product of the present disclosure is a cured product of the wavelength conversion resin composition of the present disclosure. Curing conditions for wavelength conversion the resin composition is not particularly limited, in one embodiment, it is irradiated with ultraviolet rays having a wavelength of 280 nm ~ 400 nm at an irradiation amount of ^{100mJ / cm 2 ~ 5000mJ / cm} 2. Examples of the ultraviolet source 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.
The glass transition temperature measured by dynamic viscoelasticity measurement of the cured resin for wavelength conversion is preferably 85 ° C. or higher, more preferably 85 ° C. to 160 ° C., and 90 ° C. to 120 ° C. Is even more preferable.
The cured resin for wavelength conversion of the present disclosure can be applied as a component of a wavelength conversion member.

Hereinafter, the present disclosure will be specifically described with reference to Examples, but the present disclosure is not limited to these Examples.

<Example 1>
[Preparation of Quantum Dot Fluorescent Material Processing Liquid 1]
Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by EVANS) to 100 parts by mass with a quantum dot phosphor dispersion (green, manufactured by Nanosys, Inc., quantum dot phosphor content: 15% by mass). 20 parts by mass and 20 parts by mass of a quantum dot phosphor dispersion liquid (red, manufactured by Nanosys, Inc., quantum dot phosphor content: 6% by mass) are mixed, and a mix rotor (manufactured by AS ONE, MR-5) is mixed. ) Was continued for 24 hours to prepare the quantum dot phosphor processing solution 1.

[Manufacturing of wavelength conversion member]
The materials shown below were mixed to prepare a wavelength conversion resin composition 1.
-Tricyclodecanedimethanol diacrylate (manufactured by Sartmer): 64 parts by mass-Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by EVANS): 2.2 parts by mass-Titanium oxide powder R-706 (Kemers Co., Ltd.) , Average particle size 0.36 μm): 0.5 part by mass · 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (LA-7RD, manufactured by Adeca Co., Ltd.): 0.008 Parts by mass: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO H, IGM Resins VV): 0.5 parts by mass: Quantum dot phosphor processing liquid 1:21 parts by mass

The obtained wavelength conversion resin composition 1 was applied as a coating material to a non-matte surface of a barrier film (manufactured by Dai Nippon Printing Co., Ltd.) having an average thickness of 125 μm to form a coating film. The same coating material as above was placed on this coating film. Next, ultraviolet rays were irradiated using an ultraviolet irradiation device (Igraphics Co., Ltd.) (irradiation amount: 1000 mJ / cm ² ) to cure the wavelength conversion resin composition 1, and coating materials were formed on both sides of the wavelength conversion layer. A wavelength conversion member in an arranged state was manufactured.

<Example 2>
[Preparation of Quantum Dot Fluorescent Material Processing Liquid 2]
Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by EVANS) to 100 parts by mass with a quantum dot phosphor dispersion (green, manufactured by Nanosys, Inc., quantum dot phosphor content: 15% by mass). 50 parts by mass and 50 parts by mass of a quantum dot phosphor dispersion liquid (red, manufactured by Nanosys, Inc., quantum dot phosphor content: 6% by mass) are mixed, and a mix rotor (manufactured by AS ONE, MR-5) is mixed. ) Was continued for 24 hours to prepare the quantum dot phosphor processing liquid 2.

[Manufacturing of wavelength conversion member]
The materials shown below were mixed to prepare a wavelength conversion resin composition 2.
-Tricyclodecanedimethanol diacrylate (manufactured by Sartmer): 64 parts by mass-Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by EVANS): 17.4 parts by mass-Titanium oxide powder R-706 (Kemers Co., Ltd.) , Average particle size 0.36 μm): 0.5 part by mass · 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (LA-7RD, manufactured by Adeca Co., Ltd.): 0.008 Parts by mass: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO H, IGM Resins VV): 0.5 parts by mass: Quantum dot phosphor processing liquid 2: 12 parts by mass

The obtained wavelength conversion resin composition 2 was applied as a coating material to the anti-matte surface of a barrier film (manufactured by Dai Nippon Printing Co., Ltd.) having an average thickness of 125 μm to form a coating film. The same coating material as above was placed on this coating film. Next, ultraviolet rays were irradiated using an ultraviolet irradiation device (Igraphics Co., Ltd.) (irradiation amount: 1000 mJ / cm ² ) to cure the wavelength conversion resin composition 2, and coating materials were formed on both sides of the wavelength conversion layer. A wavelength conversion member in an arranged state was manufactured.

<Example 3>
[Preparation of Quantum Dot Fluorescent Material Processing Liquid 3]
Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by EVANS) to 100 parts by mass with a quantum dot phosphor dispersion (green, manufactured by Nanosys, Inc., quantum dot phosphor content: 15% by mass). 100 parts by mass and 100 parts by mass of a quantum dot phosphor dispersion liquid (red, manufactured by Nanosys, Inc., quantum dot phosphor content: 6% by mass) are mixed, and a mix rotor (manufactured by AS ONE, MR-5) is mixed. ) Was continued for 24 hours to prepare the quantum dot phosphor processing liquid 3.

[Manufacturing of wavelength conversion member]
The materials shown below were mixed to prepare a wavelength conversion resin composition 3.
-Tricyclodecanedimethanol diacrylate (manufactured by Sartmer): 64 parts by mass-Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by EVANS): 22.4 parts by mass-Titanium oxide powder R-706 (Kemers Co., Ltd.) , Average particle size 0.36 μm): 0.5 part by mass · 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (LA-7RD, manufactured by Adeca Co., Ltd.): 0.008 Parts by mass: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO H, IGM Resins VV): 0.5 parts by mass: Quantum dot phosphor processing liquid 3: 9 parts by mass

The obtained wavelength conversion resin composition 3 was applied as a coating material to the anti-matte surface of a barrier film (manufactured by Dai Nippon Printing Co., Ltd.) having an average thickness of 125 μm to form a coating film. The same coating material as above was placed on this coating film. Next, ultraviolet rays were irradiated using an ultraviolet irradiation device (Igraphics Co., Ltd.) (irradiation amount: 1000 mJ / cm ² ) to cure the wavelength conversion resin composition 3, and coating materials were formed on both sides of the wavelength conversion layer. A wavelength conversion member in an arranged state was manufactured.

<Comparative Example 1>
[Preparation of quantum dot phosphor processing liquid C1]
Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by EVANS) to 100 parts by mass with a quantum dot phosphor dispersion (green, manufactured by Nanosys, Inc., quantum dot phosphor content: 15% by mass). 200 parts by mass and 200 parts by mass of a quantum dot phosphor dispersion liquid (red, manufactured by Nanosys, Inc., quantum dot phosphor content: 6% by mass) are mixed, and a mix rotor (manufactured by AS ONE, MR-5) is mixed. ) Was continued for 24 hours to prepare a quantum dot phosphor processing liquid C1.

[Manufacturing of wavelength conversion member]
The materials shown below were mixed to prepare a wavelength conversion resin composition C1.
-Tricyclodecanedimethanol diacrylate (manufactured by Sartmer): 64 parts by mass-Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by EVANS): 25 parts by mass-Titanium oxide powder R-706 (manufactured by Chemers Co., Ltd., Average particle size 0.36 μm): 0.5 parts by mass ・ 4-hydroxy-2,2,6,6-tetramethylpiperidin-N-oxyl (LA-7RD, manufactured by Adeca Co., Ltd.): 0.008 parts by mass -2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO H, IGM Resins B.V.): 0.5 parts by mass-Quantum dot phosphor processing liquid C1: 7.5 parts by mass

The obtained wavelength conversion resin composition C1 was applied as a coating material to the anti-matte surface of a barrier film (manufactured by Dai Nippon Printing Co., Ltd.) having an average thickness of 125 μm to form a coating film. The same coating material as above was placed on this coating film. Next, ultraviolet rays were irradiated using an ultraviolet irradiation device (Igraphics Co., Ltd.) (irradiation amount: 1000 mJ / cm ² ) to cure the wavelength conversion resin composition C1, and coating materials were formed on both sides of the wavelength conversion layer. A wavelength conversion member in an arranged state was manufactured.

<Comparative Example 2>
[Preparation of quantum dot phosphor processing liquid C2]
Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by EVANS) to 100 parts by mass with a quantum dot phosphor dispersion (green, manufactured by Nanosys, Inc., quantum dot phosphor content: 15% by mass). 330 parts by mass and 330 parts by mass of a quantum dot phosphor dispersion liquid (red, manufactured by Nanosys, Inc., quantum dot phosphor content: 6% by mass) are mixed, and a mix rotor (manufactured by AS ONE, MR-5) is mixed. ) Was continued for 24 hours to prepare a quantum dot phosphor processing liquid C2.

[Manufacturing of wavelength conversion member]
The materials shown below were mixed to prepare a wavelength conversion resin composition C2.
-Tricyclodecanedimethanol diacrylate (manufactured by Sartmer): 64 parts by mass-Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by EVANS): 26 parts by mass-Titanium oxide powder R-706 (manufactured by Chemers Co., Ltd., Average particle size 0.36 μm): 0.5 parts by mass ・ 4-hydroxy-2,2,6,6-tetramethylpiperidin-N-oxyl (LA-7RD, manufactured by Adeca Co., Ltd.): 0.008 parts by mass -2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO H, IGM Resins B.V.): 0.5 parts by mass-Quantum dot phosphor processing liquid C2: 6.9 parts by mass

The obtained wavelength conversion resin composition C2 was applied as a coating material to the anti-matte surface of a barrier film (manufactured by Dai Nippon Printing Co., Ltd.) having an average thickness of 125 μm to form a coating film. The same coating material as above was placed on this coating film. Next, ultraviolet rays were irradiated using an ultraviolet irradiation device (Igraphics Co., Ltd.) (irradiation amount: 1000 mJ / cm ² ) to cure the wavelength conversion resin composition C2, and coating materials were formed on both sides of the wavelength conversion layer. A wavelength conversion member in an arranged state was manufactured.

<Comparative Example 3>
[Preparation of quantum dot phosphor processing liquid C3]
Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by EVANS) to 100 parts by mass with a quantum dot phosphor dispersion (green, manufactured by Nanosys, Inc., quantum dot phosphor content: 15% by mass). 500 parts by mass and 500 parts by mass of a quantum dot phosphor dispersion liquid (red, manufactured by Nanosys, Inc., quantum dot phosphor content: 6% by mass) are mixed, and a mix rotor (manufactured by AS ONE, MR-5) is mixed. ) Was continued for 24 hours to prepare a quantum dot phosphor processing solution C3.

[Manufacturing of wavelength conversion member]
The materials shown below were mixed to prepare a wavelength conversion resin composition C3.
-Tricyclodecanedimethanol diacrylate (manufactured by Sartmer): 64 parts by mass-Pentaerythritol tetrakis (3-mercaptopropionate) (manufactured by EVANS): 26.5 parts by mass-Titanium oxide powder R-706 (Kemers Co., Ltd.) , Average particle size 0.36 μm): 0.5 part by mass · 4-Hydroxy-2,2,6,6-tetramethylpiperidine-N-oxyl (LA-7RD, manufactured by Adeca Co., Ltd.): 0.008 Parts by mass: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO H, IGM Resins B.V.): 0.5 parts by mass: Quantum dot phosphor processing liquid C3: 6.6 parts by mass

The obtained wavelength conversion resin composition C3 was applied as a coating material to the anti-matte surface of a barrier film (manufactured by Dai Nippon Printing Co., Ltd.) having an average thickness of 125 μm to form a coating film. The same coating material as above was placed on this coating film. Next, ultraviolet rays were irradiated using an ultraviolet irradiation device (Igraphics Co., Ltd.) (irradiation amount: 1000 mJ / cm ² ) to cure the wavelength conversion resin composition C3, and coating materials were formed on both sides of the wavelength conversion layer. A wavelength conversion member in an arranged state was manufactured.

[Measurement of | λ0-λτ |]
A wavelength conversion member was fixed to a solid sample holder of a fluorescence lifetime photometer DeltaFlex manufactured by HORIBA, Ltd. The measurement temperature was 25 ° C., and the excitation wavelength was set to 365 nm. The measurement range of the fluorescence spectrum was 450 nm to 750 nm, and the wavelength step width was set to 1 nm. The measurement time was set to 200 ns, and the number of measurement points within this measurement time range was 4096 points (number of measurement points per 1 ns: 20).
Under the above-mentioned measurement conditions, the fluorescence lifetime τ of the wavelength conversion member, the “initial fluorescence spectrum” and the “fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed” were obtained. The fluorescence lifetime τ was 30.5 ns for the green quantum dot phosphor and 31.2 ns for the red quantum dot phosphor.
Next, λ0 and λτ are obtained from the “initial fluorescence spectrum” and the “fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed”, respectively, and | λ0−λτ | Asked.
Table 1 shows | λ0-λτ | in the green quantum dot phosphor.

[Reliability test: Heat resistance test]
The obtained wavelength conversion member was cut into a circle having a diameter of 20 mm and left in a constant temperature bath at 85 ° C. The initial brightness of the wavelength conversion member before being left unattended and the brightness after being left unattended for 300 hours were measured using a fiber multi-channel spectroscope (Ocean Photonics Co., Ltd., Ocean View). A when the change in brightness after 300 hours is less than ± 5% compared to the initial brightness, B when the change is ± 5% or more and less than ± 10%, and ± 10% or more ± 20. A change of less than% was rated as C.

[Reliability test: Moisture resistance test]
The obtained wavelength conversion member was cut into a circle having a diameter of 20 mm and left in a constant temperature bath set at 65 ° C. and a relative humidity of 95%. The initial brightness of the wavelength conversion member before being left unattended and the brightness after being left unattended for 300 hours were measured using a fiber multi-channel spectroscope (Ocean Photonics Co., Ltd., Ocean View). A when the change in brightness after 300 hours is less than ± 5% compared to the initial brightness, B when the change is ± 5% or more and less than ± 10%, and ± 10% or more ± 20. A change of less than% was rated as C.

The disclosure of international patent application PCT / JP2020 / 027553 is incorporated herein by reference in its entirety.
All documents, patent applications, and technical standards described herein are to the same extent as if the individual documents, patent applications, and technical standards were specifically and individually stated to be incorporated by reference. Incorporated by reference herein.

Claims

It is a wavelength conversion member containing a quantum dot phosphor and a cured resin product containing the quantum dot phosphor.
When the peak wavelength of the fluorescence spectrum of the wavelength conversion member was measured by time-resolved fluorescence spectroscopy, the peak wavelength λ0 of the initial fluorescence spectrum and the initial fluorescence spectrum were observed in at least one of the quantum dot phosphors. A wavelength conversion member in which the absolute value (| λ0-λτ |) of the difference between the peak wavelength λτ and the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time point is 6 nm or less.
The wavelength conversion member according to claim 1, wherein the quantum dot phosphor contains a compound containing at least one of Cd and In.
It is a wavelength conversion member containing an inorganic fluorescent substance and a cured resin product containing the inorganic fluorescent substance.
When the peak wavelength of the fluorescence spectrum of the wavelength conversion member was measured by time-resolved fluorescence spectroscopy, the peak wavelength λ0 of the initial fluorescence spectrum and the time point when the initial fluorescence spectrum was observed in at least one of the inorganic phosphors. A wavelength conversion member in which the absolute value (| λ0-λτ |) of the difference between the peak wavelength λτ and the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed is 6 nm or less.
The wavelength conversion member according to any one of claims 1 to 3, which is in the form of a film.
The wavelength conversion member according to any one of claims 1 to 4, which is for displaying an image.
The wavelength conversion member according to any one of claims 1 to 5, which has a coating material that covers at least a part of the cured resin product.
The wavelength conversion member according to claim 6, wherein the covering material has a barrier property against at least one of oxygen and water.
A backlight unit including the wavelength conversion member according to any one of claims 1 to 7, and a light source.
An image display device including the backlight unit according to claim 8.
A quantum dot phosphor processing solution A containing a quantum dot phosphor and a curable compound or a curing agent, when the peak wavelength of the fluorescence spectrum of the quantum dot phosphor processing solution A is measured by time-resolved fluorescence spectroscopy. In at least one of the quantum dot phosphors, the peak wavelength λ0 of the initial fluorescence spectrum and the peak wavelength λτ of the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed. The step of preparing the quantum dot phosphor processing liquid A having an absolute difference (| λ0-λτ |) of 6 nm or less, and
A step of adding a curable compound and a curing agent to the quantum dot phosphor processing liquid A to prepare a resin composition for wavelength conversion, and a step of preparing the resin composition.
The method for manufacturing a wavelength conversion member according to claim 1 or 2, wherein the wavelength conversion member according to claim 1 or 2.
The step of preparing the quantum dot phosphor processing liquid A is
A step of preparing a plurality of quantum dot phosphor processing solutions containing the quantum dot phosphor and the curable compound or a curing agent and having different concentrations of the quantum dot phosphor.
The step of obtaining | λ0-λτ | for the plurality of quantum dot phosphor processing liquids, and
From the relationship between the concentration of the quantum dot phosphor in the quantum dot phosphor processing liquid and the | λ0-λτ |, the step of obtaining the concentration A of the quantum dot phosphor having | λ0-λτ | of 6 nm or less. When,
A step of preparing a quantum dot phosphor processing liquid A having a concentration A containing the quantum dot phosphor and the curable compound or a curing agent.
The method for manufacturing a wavelength conversion member according to claim 10.
It is an inorganic phosphor processing liquid A containing an inorganic phosphor and a curable compound or a curing agent, and when the peak wavelength of the fluorescence spectrum of the inorganic phosphor processing liquid A is measured by time-resolved fluorescence spectroscopy, the inorganic. Absolute value of the difference between the peak wavelength λ0 of the initial fluorescence spectrum and the peak wavelength λτ of the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed in at least one kind of phosphor. The step of preparing the inorganic fluorescent material processing liquid A having (| λ0-λτ |) of 6 nm or less, and
A step of adding a curable compound and a curing agent to the inorganic phosphor processing liquid A to prepare a resin composition for wavelength conversion, and a step of preparing the resin composition.
The method for manufacturing a wavelength conversion member according to claim 3.
The step of preparing the inorganic phosphor processing liquid A is
A step of preparing a plurality of inorganic phosphor processing solutions containing the inorganic phosphor and the curable compound or a curing agent and having different concentrations of the inorganic phosphor.
The step of obtaining | λ0-λτ | for the plurality of inorganic phosphor processing liquids, and
From the relationship between the concentration of the inorganic fluorescent substance in the inorganic phosphor processing liquid and the | λ0-λτ |, the step of obtaining the concentration A of the inorganic fluorescent substance having | λ0-λτ | of 6 nm or less.
A step of preparing the inorganic fluorescent substance processing liquid A having the concentration A containing the inorganic fluorescent substance and the curable compound or the curing agent, and
The method for manufacturing a wavelength conversion member according to claim 12.
It is an inorganic phosphor processing liquid containing an inorganic phosphor and a curable compound or a curing agent, and when the peak wavelength of the fluorescence spectrum of the inorganic phosphor processing liquid is measured by time-resolved fluorescence spectroscopy, the inorganic phosphor In at least one of the above, the absolute value of the difference between the peak wavelength λ0 of the initial fluorescence spectrum and the peak wavelength λτ of the fluorescence spectrum observed after the fluorescence lifetime τ has elapsed from the time when the initial fluorescence spectrum was observed (| An inorganic fluorescent material processing liquid used for preparing a resin composition for wavelength conversion having λ0−λτ |) of 6 nm or less.