JP6852401B2 - A phosphor sheet, a light emitter using the phosphor sheet, a light source unit, a display, and a method for manufacturing the light emitter. - Google Patents

Description

The present invention relates to a phosphor sheet, a light emitting body using the same, a light source unit, a display, and a method for manufacturing the light emitting body.

Light emitting diodes (LEDs, Light Emitting Diodes) are characterized by low power consumption, long life, design, etc. against the background of remarkable improvement in luminous efficiency, for backlights of liquid crystal displays (LCD, Liquid Crystal Display), and for cars. The market is expanding rapidly in the in-vehicle field such as headlights. Since LEDs have a low environmental load, they are expected to form a huge market in the general lighting field in the future.

Since the emission spectrum of an LED depends on the semiconductor material forming the LED chip, its emission color is limited. Therefore, in order to obtain white light for LCD backlights and general lighting using LEDs, it is necessary to install a phosphor suitable for each chip on the LED chip and convert the emission wavelength. Specifically, a method of installing a yellow phosphor on an LED chip that emits blue light (hereinafter, appropriately referred to as a blue LED chip), a method of installing a red phosphor and a green phosphor on a blue LED chip, and ultraviolet rays. A method of installing a red phosphor, a green phosphor, a blue phosphor, and the like on the emitting LED chip has been proposed. Among these, from the viewpoint of luminous efficiency and cost of the LED chip, a method of installing a yellow phosphor on the blue LED chip and a method of installing a red phosphor and a green phosphor on the blue LED chip are currently used. Most widely adopted.

As a phosphor used for LEDs and the like for displays, it is desired that the half width of the emission peak is narrow from the viewpoint of expanding the color reproduction range. Patent Document 1 describes an Mn-activated compound fluoride phosphor, which is a red phosphor having a narrow half-value width of an emission peak, and an Eu ²⁺ activated alkaline earth silicate nitride phosphor, which is a yellow phosphor or a green phosphor. A method of obtaining white light emission by using it is described.

Japanese Unexamined Patent Publication No. 2012-178574

However, in a light emitter using a conventional phosphor as described in Patent Document 1, it is difficult to achieve both improvement in color reproducibility and high luminous flux. An object of the present invention is to solve such a problem.

In order to solve the above-mentioned problems and achieve the object, the phosphor sheet according to the present invention includes a phosphor layer containing a red phosphor, a β-type sialon phosphor, and a resin, and the red phosphor is generally used. It is characterized in that it is an Mn-activated compound fluoride represented by the formula (1).
(General formula)
A ₂ MF ₆ : Mn ・ ・ ・ (1)
(In the general formula (1), A is one or more alkali metals selected from the group consisting of Li, Na, K, Rb and Cs and containing at least one of Na and K, and M is Si. , Ti, Zr, Hf, Ge and Sn.) One or more tetravalent elements selected from the group.

Further, in the phosphor sheet according to the present invention, in the above invention, the phosphor layer is composed of a single layer or a plurality of layers including the red phosphor, the β-type sialon phosphor and the resin, and the red fluorescence. The body, the β-type sialon phosphor and the resin are contained in the same layer.

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the refractive index of the resin is 1.45 or more and 1.7 or less.

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the resin is a silicone resin.

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the ratio of the red phosphor to the total solid content in the phosphor layer is 20% by weight or more and 60% by weight or less. To do.

Further, in the phosphor sheet according to the present invention, in the above invention, the total of the ratio of the red phosphor to the total solid content in the phosphor layer and the ratio of the β-type sialon phosphor is 50% by weight or more. , 90% by weight or less.

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the D50 of the red phosphor is 10 μm or more and 40 μm or less.

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the D10 of the red phosphor is 3 μm or more.

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the (D90-D10) / D50 of the red phosphor is 0.5 or more and 1.5 or less.

Further, the fluorescent substance sheet according to the present invention is characterized in that, in the above invention, the porosity in the fluorescent substance layer is 0.1% or more and 3% or less.

Further, the fluorescent substance sheet according to the present invention is characterized in that, in the above invention, the fluorescent substance layer contains fine particles.

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the fine particles are silicone fine particles.

Further, the fluorescent material sheet according to the present invention is characterized in that, in the above invention, a transparent resin layer is further laminated on the fluorescent material layer.

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the refractive index of the resin contained in the transparent resin layer is 1.3 or more and 1.6 or less.

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the refractive index of the resin contained in the transparent resin layer is equal to or lower than the refractive index of the resin contained in the phosphor layer.

Further, the fluorescent material sheet according to the present invention is characterized in that, in the above invention, the transparent resin layer contains fine particles.

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the fine particles contained in the transparent resin layer are one or more selected from silica fine particles, alumina fine particles, and silicone fine particles.

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the minimum transmittance of the transparent resin layer at a wavelength of 400 nm to 800 nm is 80% or more.

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the ratio of fine particles to the total solid content in the transparent resin layer is 0.1% by weight or more and 30% by weight or less. ..

Further, the phosphor sheet according to the present invention is characterized in that, in the above invention, the average particle size of the fine particles contained in the transparent resin layer is 1 nm or more and 1000 nm or less.

Further, the method for producing a light emitting body according to the present invention includes a step of individualizing the fluorescent substance sheet according to any one of the above inventions, and picking up the individualized fluorescent substance sheet. It is characterized by including a pick-up step and a sticking step of sticking the individualized phosphor sheet to a light source.

Further, the light emitting body according to the present invention is characterized by including the phosphor sheet according to any one of the above inventions.

Further, the light source unit according to the present invention is characterized by including the phosphor sheet according to any one of the above inventions.

Further, the display according to the present invention is characterized by including the light source unit described in the above invention.

According to the present invention, it is possible to provide a phosphor sheet that achieves both improved color reproducibility and high luminous flux. The light emitter, the light source unit, and the display provided with the phosphor sheet according to the present invention have an effect that both improvement in color reproducibility and high brightness can be achieved at the same time.

FIG. 1A is a side view showing an example of a fluorescent material sheet according to an embodiment of the present invention. FIG. 1B is a side view showing another example of the phosphor sheet according to the embodiment of the present invention. FIG. 2 is a process diagram showing an example of a method for manufacturing a light emitter using a phosphor sheet according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the phosphor sheet according to the present invention, a light emitting body using the same, a light source unit, a display, and a method for manufacturing the light emitting body will be described in detail. However, the present invention is not limited to the following embodiments, and can be variously modified and implemented according to an object and an application.

<Fluorescent sheet>
The phosphor sheet according to the embodiment of the present invention contains a phosphor layer containing a red phosphor, a β-type sialone phosphor, and a resin. In this phosphor sheet, the red phosphor is a Mn-activated compound fluoride represented by the general formula (1).

A ₂ MF ₆ : Mn ・ ・ ・ (1)

In the general formula (1), A is selected from the group consisting of lithium (Li), sodium (Na), potassium (K), rubidium (Rb) and cesium (Cs), and contains at least one of Na and K. One or more alkali metals including. M is one or more tetravalent elements selected from the group consisting of silicon (Si), titanium (Ti), zirconium (Zr), hafnium (Hf), germanium (Ge) and tin (Sn).

FIG. 1A is a side view showing an example of a fluorescent material sheet according to an embodiment of the present invention. As shown in FIG. 1A, the phosphor sheet 4 according to the embodiment of the present invention includes a phosphor layer 2 containing a phosphor 1 and a resin 14 on a support 3. The phosphor layer 2 is a layer containing a plurality of phosphors 1 in the resin 14. The phosphor layer 2 contains, as the phosphor 1, a red phosphor represented by the general formula (1) and a β-type sialon phosphor. For example, as shown in FIG. 1A, the phosphor layer 2 is formed on the support 3 to form the phosphor sheet 4.

The phosphor layer 2 may be composed of a single layer containing a red phosphor as the phosphor 1 and a β-type sialon phosphor, and a resin 14. Alternatively, the phosphor layer 2 may be composed of a plurality of layers containing the phosphor 1 and the resin 14. When the phosphor layer 2 is composed of a plurality of layers, it contains a first phosphor layer containing a red phosphor and a resin 14 as the phosphor 1, and a β-type sialon phosphor and a resin 14 as the phosphor 1. One or more of the second phosphor layers to be formed may be laminated to form a plurality of layers of the phosphor layer 2. Preferably, in each of the single layer or the plurality of layers constituting the phosphor layer 2, the red phosphor as the phosphor 1 and the β-type sialon phosphor and the resin 14 are contained in the same layer. This is due to the following reasons.

Even if the phosphor layer 2 is a laminate of a layer containing a red phosphor (first phosphor layer) and a layer containing a β-type sialon phosphor (second phosphor layer), the color reproducibility is high. Although it is possible to achieve both improvement and high luminous flux, it is necessary to control the film thickness of each layer separately in the phosphor layer 2. Therefore, the chromaticity variation of the resulting phosphor sheet 4 becomes large. On the other hand, in the phosphor layer 2, the red phosphor as the phosphor 1 and the β-type sialon phosphor and the resin 14 are contained in the same layer, so that the chromaticity variation of the phosphor sheet 4 is improved.

FIG. 1B is a side view showing another example of the phosphor sheet according to the embodiment of the present invention. As shown in FIG. 1B, the phosphor sheet 4 may further include a transparent resin layer 5 on the phosphor layer 2 formed on the support 3. In the phosphor sheet 4 shown in FIG. 1B, the transparent resin layer 5 is formed on, for example, the upper surface (the surface opposite to the support 3) of the phosphor layer 2 composed of a single layer or a plurality of layers. The presence of the transparent resin layer 5 in this way improves the durability of the phosphor sheet 4.

In the present embodiment, the fluorescent material sheet 4 is provided with a single layer or a plurality of layers of the fluorescent material layer 2, or is provided with the fluorescent material layer 2 and the transparent resin layer 5. From the viewpoint of maintaining the shape and ease of handling, it is usually in a state of being supported by the support 3. That is, in the present embodiment, the phosphor sheet 4 and the support 3 may be collectively referred to as a "fluorescent sheet".

<Fluorescent layer>
The phosphor layer 2 is a layer mainly containing the phosphor 1 and the resin 14, as shown in FIGS. 1A and 1B, for example. Examples of the fluorescent substance 1 include at least a red fluorescent substance represented by the general formula (1) and a β-type sialone fluorescent substance.

(Red phosphor)
The red phosphor is a phosphor having an emission peak at a wavelength of 590 nm to 750 nm. In order to improve the color reproducibility of the fluorescent substance sheet 4 according to the embodiment of the present invention, the Mn-activated difluoride (A _{2) represented by the general formula (1) described above is contained in the fluorescent substance layer 2.} It is necessary to contain a red phosphor which is MF _{6: Mn).} The red phosphor which is the Mn-activated compound fluoride is referred to as "Mn-activated compound fluoride complex phosphor". Hereinafter, the Mn-activated difluoride complex phosphor is abbreviated as “red phosphor” as appropriate.

The Mn-activated compound fluoride complex phosphor is a phosphor having manganese (Mn) as an activator and a fluoride complex salt of an alkali metal or an alkaline earth metal as a parent crystal. In this Mn-activated compound fluoride complex phosphor, the coordination center of the fluoride complex forming the parent crystal is preferably a tetravalent metal (Si, Ti, Zr, Hf, Ge, Sn), and around it. The number of coordinating fluorine atoms is preferably 6. A preferred Mn-activated difluoride complex phosphor is one in which A is K (potassium) and M is Si (silicon) in the general formula (1), that is, K ₂ SiF ₆ : Mn. This is called a KSF phosphor.

The ratio of the red phosphor (that is, the Mn-activated difluoride complex phosphor) to the total solid content in the phosphor layer 2 is preferably 10% by weight or more, and more preferably 20% by weight or more. Further, this ratio is preferably 80% by weight or less, and more preferably 60% by weight or less. When this ratio is at least a preferable lower limit value, the color reproduction range of the phosphor sheet 4 is further improved. On the other hand, when this ratio is 80% by weight or less, the chromaticity variation of the phosphor sheet 4 is improved, and when this ratio is 60% by weight or less, the chromaticity variation of the phosphor sheet 4 is further improved. To.

The D50 of the red phosphor as the phosphor 1 (see FIG. 1A) is preferably 5 μm or more, and more preferably 10 μm or more. The D50 of this red phosphor is preferably 40 μm or less, and more preferably 30 μm or less. When the D50 of this red phosphor is 5 μm or more, a phosphor sheet 4 having a high luminous flux can be obtained. When the D50 of the red phosphor is 40 μm or less, the chromaticity variation of the phosphor sheet 4 is improved.

The D10 of the red phosphor as the phosphor 1 is preferably 3 μm or more, and more preferably 5 μm or more. This improves the durability of the phosphor sheet 4. The upper limit of D10 of this red phosphor is not particularly limited, but is preferably 15 μm or less, and more preferably 12 μm or less.

Further, in the red phosphor as the phosphor 1, the value x represented by the following formula (11) is preferably 0.5 or more and 1.8 or less, and more preferably 1.5 or less. preferable. Furthermore, the upper limit of this value x is preferably 1.50 or less, more preferably 1.4 or less, even more preferably 1.35 or less, and preferably 1 or less. More preferred.

x = (D90-D10) / D50 ... (11)

The value x is an index of the particle size distribution of the red phosphor. A small value x means that there are few red phosphors having a small particle size (for example, KSF phosphors) that cause a decrease in durability, and there are few red phosphors having a large particle size (for example, KSF) that cause chromaticity variation. It means that there are few (fluorescent substances). When the value x is 1.5 or less, the durability and chromaticity variation of the phosphor sheet 4 are further improved.

However, if the particle size distribution of the red phosphor in the phosphor layer 2 is too narrow, it becomes difficult for light to scatter in the phosphor sheet 4. In this case, when the light emitter is assembled using the phosphor sheet 4, a problem called a yellow ring occurs. The yellow ring is a phenomenon in which the colors look different when the light emitter is viewed from the front and when it is viewed from an oblique direction. This yellow ring is a phenomenon that is remarkably observed when the scattering of light in the phosphor layer 2 is small. From the viewpoint of suppressing yellow ring, the value x is preferably 0.5 or more.

The terms D10, D50, and D90 referred to here are particle sizes measured by the following methods. For example, the cross section of the phosphor layer 2 is observed by SEM, and in the obtained two-dimensional image, the maximum distance between the two intersections of the straight line intersecting the outer edge of the particles of the phosphor 1 at two points is the maximum. Is calculated and defined as the individual particle size of the particles. In the particle size distribution obtained from the individual particle sizes of all the observed particles, the particle size of 10% of the accumulated passages from the small particle size side is D10, and the particle size of 50% of the accumulated passages (average particle size) is D50. Let D90 be the particle size of 90% of the accumulated passage amount.

When the LED light emitter on which the phosphor sheet 4 is mounted is targeted, this fluorescence can be obtained by any of the mechanical polishing method, the microtome method, the CP method (Cross-section Polisher) and the focused ion beam (FIB) processing method. After polishing the body sheet 4 so that the cross section of the phosphor layer 2 can be observed, the above-mentioned particle size can be calculated from the two-dimensional image obtained by observing the obtained cross section with an SEM.

(Β-type sialone phosphor)
The β-type sialon phosphor is a solid solution of β-type silicon nitride, in which aluminum (Al) is substituted and solid-solved at the Si position of the β-type silicon nitride crystal, and oxygen (O) is substituted and solid-dissolved at the nitrogen (N) position. It was done. Since there are two types of atoms in the unit cell (unit cell) of β-type sialon used for β-type sialon phosphor, Si _6-z Al _{z Oz} N _8-z is used as a general formula for β-type sialon. Be done. In this general formula, z is a value greater than 0 and less than 4.2. In the β-type sialone phosphor in the present embodiment, the solid solution range of β-type sialon is very wide, and the molar ratio of (Si, Al) / (N, O) needs to be maintained at 3/4. is there. A general method for producing β-type sialon is a method in which silicon oxide and aluminum nitride, or aluminum oxide and aluminum nitride are added and heated in addition to silicon nitride.

β-type sialone is a β-type sialon that is excited by blue light from ultraviolet rays by incorporating luminescent elements such as rare earths (Eu, Sr, Mn, Ce, etc.) into the crystal structure and exhibits green light emission with a wavelength of 520 nm to 560 nm. It becomes a phosphor. This is preferably used as a green light emitting component of a light emitting body such as a white LED. In particular, ^{the Eu 2+} activated β-type sialone phosphor, which is a β-type sialone phosphor containing ^{europium (Eu 2+} ), has a very sharp emission spectrum, so that it emits narrow bands of blue, green, and red. It is a material suitable for a required image processing display device or a backlight source of a liquid crystal display panel.

The D50 of the β-type sialon phosphor as the phosphor 1 (see FIG. 1A) is preferably 1 μm or more, more preferably 10 μm or more. The D50 of this β-type sialon phosphor is preferably 100 μm or less, more preferably 50 μm or less. The shape of the β-type sialon phosphor is not particularly limited, and various shapes such as spherical and columnar can be used. The D50 referred to here is a particle size measured by the same method as in the case of the red phosphor described above.

The content of the β-type sialon phosphor as the phosphor 1 in the phosphor layer 2 is preferably 3% by weight or more of the entire phosphor layer 2 from the viewpoint of expanding the color reproduction range, and is preferably 3% by weight or more of the entire phosphor layer 2. More preferably, it is 5% by weight or more. The content of the β-type sialon phosphor is preferably 50% by weight or less of the entire phosphor layer 2, and more preferably 40% by weight or less of the entire phosphor layer 2.

Further, the total of the ratio of the red phosphor to the total solid content in the phosphor layer 2 and the ratio of the β-type sialon phosphor is preferably 50% by weight or more and 90% by weight or less. The lower limit of the total of these two ratios is more preferably 65% by weight or more, and further preferably 70% by weight or more. The upper limit of the total of these two ratios is more preferably 85% by weight or less, and further preferably 80% by weight or less. When the total of these two ratios is 50% by weight or more, the heat dissipation of the phosphor layer 2 is improved, so that the heat storage of the phosphor 1 contained in the phosphor layer 2 can be suppressed. As a result, the high luminous flux of the phosphor sheet 4 can be maintained. Further, when the total of these two ratios is 90% by weight or less, the chromaticity variation of the phosphor sheet 4 is improved.

In the phosphor sheet 4 having the red phosphor and the β-type sialon phosphor as the phosphor 1 in the phosphor layer 2 in the present invention, the porosity in the phosphor layer 2 is preferably 3% or less, 2 It is more preferably% or less, further preferably 1% or less, and further preferably 0.5% or less. This is because the smaller the porosity in the phosphor layer 2, the higher the efficiency of extracting light from the phosphor layer 2, so that the phosphor sheet 4 that gives a high luminous flux illuminant can be obtained. .. The porosity in the phosphor layer 2 is not particularly limited at the lower limit, but is preferably 0.1% or more.

The porosity here is the ratio of voids in the phosphor layer 2. This porosity can be measured by the following method. For example, the cross section of the phosphor layer 2 can be observed on the phosphor sheet 4 by any of the mechanical polishing method, the microtome method, the CP method (Cross-section Polisher) and the focused ion beam (FIB) processing method. Grind. Then, the area corresponding to the voids of the phosphor layer 2 is calculated from the two-dimensional image obtained by observing the obtained cross section with SEM, and the calculated area of the voids is the area of the entire phosphor layer 2 in the cross section. Divide by area. As a result, the porosity of the phosphor layer 2 can be obtained.

By setting D10 and D50 of the red phosphor contained in the phosphor layer 2 in the above-mentioned preferable range, and by setting the above-mentioned value x (see formula (11)), which is an index of the particle size distribution of the red phosphor, to be small. By doing so, the porosity of the phosphor layer 2 tends to be small.

(Other phosphors)
The phosphor layer 2 may further contain a fluorescent substance other than the above-mentioned fluorescent substance 1. Examples of the phosphor other than the above-mentioned phosphor 1 include other red phosphors, other green phosphors, yellow phosphors, blue phosphors and the like. In the present embodiment, the green phosphor is a phosphor having an emission peak at a wavelength of 500 nm to 560 nm. The yellow phosphor is a phosphor having an emission peak at a wavelength of 560 nm to 590 nm. The blue phosphor is a phosphor having an emission peak at a wavelength of 430 nm to 500 nm.

The other red phosphor is other than the red phosphor (Mn activated difluoride complex phosphor) represented by the general formula (1). Examples of such other red phosphors include Y ₂ O ₂ S: Eu, La ₂ O ₂ S: Eu, Y ₂ O ₃ : Eu, Gd ₂ O ₂ S: Eu and the like.

Other green phosphors are other than β-type sialone phosphors. Other such green phosphors include, for example, SrAl ₂ O ₄ : Eu, Y ₂ SiO ₅ : Ce, Tb, MgAl ₁₁ O ₁₉ : Ce, Tb, Sr ₇ Al ₁₂ O ₂₅ : Eu, (Mg, Ca). , Sr, Ba at least one element) Ga ₂ S ₄ : Eu and the like.

As the yellow phosphors, for example, at least a cerium-activated yttrium-aluminum oxide phosphor, at least a cerium-activated yttrium-gadolinium-aluminum oxide phosphor, and at least a cerium-activated yttrium-gallium. Examples include aluminum oxide phosphors.

Examples of the blue phosphor include Sr ₅ (PO ₄ ) ₃ Cl: Eu, (SrCaBa) ₅ (PO ₄ ) ₃ Cl: Eu, (BaCa) ₅ (PO ₄ ) ₃ Cl: Eu, (Mg, Ca, Sr). , At least one element of Ba) ₂ B ₅ O ₉ Cl: Eu, Mn, (at least one element of Mg, Ca, Sr, Ba) (PO ₄ ) ₆ Cl ₂ : Eu, Mn And so on.

Further, as a phosphor that emits light corresponding to the currently mainstream blue LED, for example, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, (Y, Gd) ₃ Al ₅ O ₁₂ : Ce, Lu ₃ Al ₅ O ₁₂ : Ce, Y ₃ Al ₅ O ₁₂ : YAG-based fluorescent material such as Ce, Tb ₃ Al ₅ O ₁₂ : TAG-based fluorescent material such as Ce, (Ba, Sr) ₂ SiO ₄ : Eu-based fluorescent material and Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce-based phosphor, (Sr, Ba, Mg) ₂ SiO ₄ : Silicate-based phosphor such as Eu, (Ca, Sr) ₂ Si ₅ N ₈ : Eu, (Ca, Sr) AlSiN ₃ : Eu, CaSiAlN ₃ : Nitride-based phosphors such as Eu, Ca _y (Si, Al) ₁₂ (O, N) ₁₆ : Oxynitride-based phosphors such as Eu, and further (Ba, Sr, Ca) ) Si ₂ O ₂ N ₂ : Eu-based phosphor, Ca ₈ MgSi ₄ O ₁₆ Cl ₂ : Eu-based phosphor, SrAl ₂ O ₄ : Eu, Sr ₄ Al ₁₄ O ₂₅ : Eu and the like.

(resin)
The refractive index of the resin 14 contained in the phosphor layer 2 is 1.45 or more and 1.7 or less. The refractive index of the resin 14 is more preferably 1.5 or more, and more preferably 1.65 or less. When the refractive index of the resin 14 is 1.45 or more, the refractive index with the Mn-activated compound fluoride complex phosphor (red phosphor as the phosphor 1) having an average refractive index of around 1.4. The difference becomes large, and light tends to be scattered in the phosphor layer 2. Therefore, the optical path length from when the light enters the phosphor layer 2 to when it exits becomes long. As the optical path length becomes longer, the blue light emitted from the LED chip is easily color-converted by the phosphor 1 in the phosphor layer 2, so that the amount of the phosphor for expressing the desired chromaticity should be reduced. Can be done.

On the other hand, when the refractive index of the resin 14 exceeds 1.7, the optical path length becomes longer than necessary due to excessive scattering of light in the phosphor layer 2. Therefore, the emitted light emitted from the phosphor 1 in the phosphor layer 2 is easily absorbed by the phosphor 1, and as a result, the intensity of the light emitted from the emitter is lowered.

The material of the resin 14 is not particularly limited as long as it can uniformly disperse a phosphor (such as the phosphor 1 shown in FIG. 1A) inside and can form the phosphor layer 2. Examples of such a resin 14 include silicone resin, epoxy resin, polyarylate resin, PET-modified polyarylate resin, polycarbonate resin, cyclic olefin resin, polyethylene terephthalate resin, polymethylmethacrylate resin, polypropylene resin, and modified acrylic resin. Examples thereof include polystyrene resin and acrylic nitrile / styrene copolymer resin. Of these, silicone resin and epoxy resin are preferable from the viewpoint of transparency. Further, a silicone resin is particularly preferable from the viewpoint of heat resistance.

As the silicone resin which is an example of the resin 14 used in the present invention, a curable silicone resin is preferable. The curable silicone resin used as the resin 14 may have either a one-component type or a two-component type (three-component type). The curable silicone resin includes a de-alcohol type, a de-oxime type, a deacetic acid type, a dehydroxylamine type and the like as a type that causes a condensation reaction by moisture in the air or a catalyst. Further, in this curable silicone resin, there is an addition reaction type as a type that causes a hydrosilylation reaction by a catalyst. As the resin 14, any of these types of curable silicone resin may be used. In particular, the addition reaction type silicone resin is more preferable because it has no by-products associated with the curing reaction, has a small curing shrinkage, and can be easily cured by heating.

The addition reaction type silicone resin as an example of the resin 14 is formed by, for example, a hydrosilylation reaction between a compound containing an alkenyl group bonded to a silicon atom and a compound having a hydrogen atom bonded to a silicon atom. Examples of the "compound containing an alkenyl group bonded to a silicon atom" include vinyltrimethoxysilane, vinyltriethoxysilane, allyltrimethoxysilane, propenyltrimethoxysilane, norbornenyltrimethoxysilane, and octenyltrimethoxysilane. And so on. Examples of the "compound having a hydrogen atom bonded to a silicon atom" include methylhydrogenpolysiloxane, dimethylpolysiloxane-CO-methylhydrogenpolysiloxane, ethylhydrogenpolysiloxane, and methylhydrogenpolysiloxane-CO-methyl. Examples include phenylpolysiloxane. Examples of the addition reaction type silicone resin include those formed by the hydrosilylation reaction of such a material. Further, as the resin 14, for example, known ones as described in JP-A-2010-159411 can be used.

As such a resin 14, it is also possible to use a commercially available resin 14, for example, a silicone encapsulant for general LED applications. Specific examples of this include OE-6630A / B and OE-6336A / B manufactured by Toray Dow Corning Co., Ltd. and SCR-1012A / B and SCR-1016A / B manufactured by Shin-Etsu Chemical Co., Ltd.

Further, the silicone resin as the resin 14 may have heat-sealing properties. This is because when the resin 14 of the phosphor layer 2 is a silicone resin having heat-sealing property, the phosphor sheet 4 provided with the phosphor layer 2 has heat-sealing property, and this heat-sealing property This is because the phosphor sheet 4 having the above can be heated and attached to the LED chip. The heat-sealing property referred to here is a property of being softened by heating. When the phosphor sheet 4 has heat-sealing properties, it is not necessary to use an adhesive for attaching the phosphor sheet 4 to the LED chip, so that the manufacturing process of the light emitter or the like can be simplified. In the phosphor layer 2 of the heat-sealing phosphor sheet 4, the storage elastic modulus at 25 ° C. is 0.1 MPa or more, and the storage elastic modulus at 100 ° C. is less than 0.1 MPa.

As an example of the heat-sealing silicone resin, a crosslinked product obtained by hydrosilylating a crosslinkable silicone composition containing the compositions of the components (A) to (D) shown below is particularly preferable. This crosslinked product has a storage elastic modulus decreased at 60 ° C. to 250 ° C. and a high adhesive strength can be obtained by heating, so that it can be preferably used as a matrix resin for a fluorescent material sheet 4 that does not require an adhesive.

The component (A) is an organopolysiloxane represented by the following average unit formula (21).

(R ¹ ₂ SiO _2/2 ) _a (R ¹ SiO _3/2 ) _b (R ² O _1/2 ) _c・ ・ ・ (21)

In the average unit formula (21), R ¹ is a phenyl group, an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group, or an alkenyl group having 2 to 6 carbon atoms. However, 65 mol% to 75 mol% of R ¹ is a phenyl group, 10 mol% to 20 mol% of R ¹ is an alkenyl group. R ² is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms. a, b, and c are numbers that satisfy 0.5 ≦ a ≦ 0.6, 0.4 ≦ b ≦ 0.5, 0 ≦ c ≦ 0.1, and a + b = 1.

The component (B) is an organopolysiloxane represented by the following general formula (2). This organopolysiloxane has a content in the range of 5 to 15 parts by weight with respect to 100 parts by weight of the component (A).

R ³ ₃ SiO (R ³ ₂ SiO) _m SiR ³ ₃ ... (2)

In the general formula (2), R ³ is a phenyl group, an alkyl group having 1 to 6 carbon atoms or a cycloalkyl group, or an alkenyl group having 2 to 6 carbon atoms. However, 40 mol% to 70 mol% of R ³ is a phenyl group, at least one R ³ is an alkenyl group. m is an integer in the range of 5 to 50.

The component (C) is an organotrisiloxane represented by the following general formula (3). In this organotrisiloxane, the molar ratio of the silicon atom-bonded hydrogen atom in the component (C) to the total of the alkenyl group in the component (A) and the alkenyl group in the component (B) is within the range of 0.5 to 2. It is the amount that becomes.

(HR ⁴ ₂ SiO) ₂ SiR ⁴ ₂ ... (3)

In the general formula (3), R ⁴ is a phenyl group, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group. However, 30 mol% to 70 mol% of ^{R 4 is a phenyl group.}

The component (D) is a catalyst for the hydrosilylation reaction. This hydrosilylation reaction catalyst is in an amount sufficient to promote the hydrosilylation reaction between the alkenyl group in the components (A) and (B) and the silicon atom-bonded hydrogen atom in the component (C). ..

When the values of a, b, and c in the average unit formula (21) of the component (A) satisfy the above conditions, sufficient hardness of the obtained crosslinked product at room temperature can be obtained, and at a high temperature of the crosslinked product. Softening is obtained. In the general formula (2) of the component (B), if the content of the phenyl group is less than the lower limit of the above range, the obtained crosslinked product is insufficiently softened at high temperature. On the other hand, when the content of the phenyl group exceeds the upper limit of the above range, the transparency of the obtained crosslinked product is lost and its mechanical strength is also lowered. Further, in the general formula (2), ^{at least one of R 3} is an alkenyl group. This is because if the component (B) does not have an alkenyl group, the component (B) is not incorporated into the cross-linking reaction, and the component (B) may bleed out from the obtained cross-linked product. Further, in the general formula (2), m is an integer in the range of 5 to 50. The numerical range of m is a range in which handling workability can be maintained while maintaining the mechanical strength of the obtained crosslinked product.

The content of the component (B) is in the range of 5 to 15 parts by weight with respect to 100 parts by weight of the component (A). The range of this content is the range for obtaining sufficient softening of the obtained crosslinked product at high temperature.

In the general formula (3) of the component (C), R ⁴ is a phenyl group, an alkyl group having 1 to 6 carbon atoms, or a cycloalkyl group. Examples of the alkyl group of R ⁴ include a methyl group, an ethyl group, a propyl group, a butyl group, a pentyl group, and a heptyl group. Examples of the cycloalkyl group of R ⁴ include a cyclopentyl group and a cycloheptyl group. The content of the phenyl group in R ⁴ is in the range of 30 mol% to 70 mol%. The range of this content is a range in which sufficient softening of the obtained crosslinked product at high temperature can be obtained, and the transparency and mechanical strength of the crosslinked product can be maintained.

Regarding the content of the component (C), the molar ratio of the silicon atom-bonded hydrogen atom in the component (C) to the total of the alkenyl group in the component (A) and the alkenyl group in the component (B) is 0. The amount is in the range of 5 to 2. The range of this content is the range in which sufficient hardness of the obtained crosslinked product at room temperature can be obtained.

The component (D) is a catalyst for a hydrosilylation reaction for promoting the hydrosilylation reaction between the alkenyl group in the components (A) and (B) and the silicon atom-bonded hydrogen atom in the component (C). Examples of the component (D) include a platinum-based catalyst, a rhodium-based catalyst, and a palladium-based catalyst. Of these, a platinum-based catalyst is preferable because it can remarkably accelerate the curing of the silicone composition. Examples of this platinum-based catalyst include platinum fine powder, platinum chloride acid, an alcohol solution of platinum chloride acid, a platinum-alkenylsiloxane complex, a platinum-olefin complex, and a platinum-carbonyl complex. In particular, the platinum-based catalyst is preferably a platinum-alkenylsiloxane complex. Examples of this alkenyl siloxane include 1,3-divinyl-1,1,3,3-tetramethyldisiloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane. Examples thereof include alkenylsiloxanes in which some of the methyl groups of these alkenylsiloxanes are substituted with ethyl groups, phenyl groups, etc., and alkenylsiloxanes in which the vinyl groups of these alkenylsiloxanes are substituted with allyl groups, hexenyl groups, etc. In particular, 1,3-divinyl-1,1,3,3-toteramethyldisiloxane is preferable because the stability of this platinum-alkenylsiloxane complex is good.

Further, since the stability of this platinum-alkenylsiloxane complex can be improved, 1,3-divinyl-1,1,3,3-tetramethyldisiloxane and 1,3-diallyl- 1,1,3,3-tetramethyldisiloxane, 1,3-divinyl-1,3-dimethyl-1,3-diphenyldisiloxane, 1,3-divinyl-1,1,3,3-tetraphenyldisiloxane It is preferable to add an alkenylsiloxane such as siloxane, 1,3,5,7-tetramethyl-1,3,5,7-tetravinylcyclotetrasiloxane or an organosiloxane oligomer such as dimethylsiloxane oligomer. In particular, it is preferable to add alkenylsiloxane to this complex.

The content of the component (D) is sufficient to promote the hydrosilylation reaction between the alkenyl group in the components (A) and (B) and the silicon atom-bonded hydrogen atom in the component (C). There is no particular limitation. Preferably, the content of the component (D) is such that the metal atoms in the component (D) are in the range of 0.01 ppm to 500 ppm in mass units with respect to the silicone composition. Further, the content of the component (D) is preferably an amount in which the metal atom is in the range of 0.01 ppm to 100 ppm, and particularly, the metal atom is in the range of 0.01 ppm to 50 ppm. The amount is preferable. The range of this content is a range in which the obtained silicone composition is sufficiently crosslinked and problems such as coloring do not occur.

On the other hand, the ratio of the resin 14 to the total solid content in the phosphor layer 2 is preferably 10% by weight or more and 60% by weight or less. This is because, by setting the ratio of the resin 14 in the above range, it is possible to achieve both improvement in color reproducibility and high durability of the phosphor sheet 4.

The refractive index of the resin 14 can be measured by measuring the refractive index of the refractive index measurement sample using a refractive index / film thickness measuring device “Prism Coupler MODEL2010 / M” (manufactured by Metricon). For the refractive index measurement sample, the resin 14 was stirred and defoamed at 1000 rpm for 10 minutes using a planetary stirring defoaming device "Mazelstar KK-400" (manufactured by Kurabo) to prepare a dispersion of the resin 14. This dispersion can be obtained by dropping 5 cc of this dispersion onto a PET film and then heating it in an oven at 150 ° C. for 1 hour.

(Fine particles)
The phosphor sheet 4 according to the embodiment of the present invention contains fine particles in the phosphor layer 2 for the purpose of improving the dispersion stability of the phosphor 1 in the phosphor layer 2 in the resin 14. May be good. Examples of these fine particles include fine particles composed of titania, silica, alumina, silicone, zirconia, ceria, aluminum nitride, silicon carbide, silicon nitride, barium titanate and the like. These may be used alone or in combination of two or more. As the fine particles contained in the phosphor layer 2, silica fine particles, alumina fine particles, and silicone fine particles are preferable from the viewpoint of easy availability, and silicone fine particles are particularly preferable from the viewpoint of low hardness. Since the hardness of the fine particles is low, there is an effect of suppressing the crushing of the red phosphor in the dispersion step of the phosphor 1, and as a result, it is possible to obtain the phosphor sheet 4 having higher emission intensity.

Examples of silicone fine particles include, in particular, hydrolyzing and then condensing organosilanes such as organotrialkoxysilane, organodialkoxysilane, organotriacetoxysilane, organodiacetoxysilane, organotrioxymsilane, and organodioxymsilane. Examples thereof include silicone fine particles obtained by the method.

Examples of the organotrialkoxysilane include methyltrimethoxysilane, methyltriethoxysilane, methyltri-n-proxysilane, methyltri-i-proxysilane, methyltri-n-butoxysilane, methyltri-i-butoxysilane, and methyltri-s. -Butoxysilane, methyltri-t-butoxysilane, ethyltrimethoxysilane, n-propyltrimethoxysilane, i-propyltrimethoxysilane, n-butyltributoxysilane, i-butyltributoxysilane, s-butyltrimethoxysilane , T-Butyltributoxysilane, N-β (aminoethyl) γ-aminopropyltrimethoxysilane, γ-glycidoxypropyltrimethoxysilane, vinyltrimethoxysilane, phenyltrimethoxysilane and the like.

Examples of the organodialkoxysilane include dimethyldimethoxysilane, dimethyldiethoxysilane, methylethyldimethoxysilane, methylethyldiethoxysilane, diethyldiethoxysilane, diethyldimethoxysilane, 3-aminopropylmethyldiethoxysilane, and N- (. 2-Aminoethyl) -3-aminopropylmethyldimethoxysilane, N- (2-aminoethyl) -3-aminoisobutylmethyldimethoxysilane, N-ethylaminoisobutylmethyldiethoxysilane, (phenylaminomethyl) methyldimethoxysilane, Examples thereof include vinyl methyl diethoxysilane.

Examples of the organotriacetoxysilane include methyltriacetoxysilane, ethyltriacetoxysilane, vinyltriacetoxysilane, and the like. Examples of the organodiacetoxysilane include dimethyldiacetoxysilane, methylethyldiacetoxysilane, vinylmethyldiacetoxysilane, and vinylethyldiacetoxysilane. Examples of the organotrioxymsilane include methyltrismethylethylketooximesilane and vinyltrismethylethylketooximesilane. Examples of the organodioxime silane include methyl ethyl bismethyl ethyl keto oxime silane.

Specific examples of such fine particles (fine particles contained in the phosphor layer 2) are the methods reported in JP-A-63-77940 and the methods reported in JP-A-6-248081. , Can be obtained by the method reported in JP-A-2003-342370, the method reported in JP-A-4-88022, and the like. Further, at least one of organosilanes such as organotrialkoxysilane, organodialkoxysilane, organotriacetoxysilane, organodiacetoxysilane, organotrioxymsilane, and organodioxymsilane and a partial hydrolyzate thereof is added to the alkaline aqueous solution. Then, hydrolyze and condense to obtain fine particles, or add at least one of organosilane and its partial hydrolyzate to water or an acidic solution, and hydrolyze at least one of the organosilane and its partial hydrolyzate. After obtaining a partial condensate, an alkali is added to proceed with the condensation reaction to obtain fine particles. At least one of organosilane and its hydrolyzate is placed in the upper layer, and an alkali or a mixed solution of alkali and an organic solvent is placed in the lower layer. Then, a method of hydrolyzing and polycondensing at least one of the organosilane and its hydrolyzate at these interfaces to obtain fine particles is also known. In any of these methods, the fine particles contained in the phosphor layer 2 can be obtained in the present invention.

Among these, in producing spherical organopolysilsesquioxane fine particles by hydrolyzing and condensing at least one of organosilane and its partial hydrolyzate, as reported in JP-A-2003-342370. It is preferable to use the silicone fine particles obtained by the method of adding the polymer dispersant into the reaction solution.

In the present invention, the average particle size of the silicone fine particles is represented by D50. The lower limit of the average particle size is preferably 0.05 μm or more, and more preferably 0.1 μm or more. The upper limit of the average particle size is preferably 2.0 μm or less, and more preferably 1.0 μm or less. By using such silicone fine particles, it is possible to obtain a phosphor layer 2 having excellent ejection properties and excellent film thickness uniformity when a slit die coater is used. Further, it is preferable to use monodisperse and spherical silicone fine particles. The average particle size (D50) of the silicone fine particles can be determined by the same method as the average particle size of the red phosphor as the phosphor 1 described above.

The ratio of the fine particles to the total solid content in the phosphor layer 2 is preferably 0.1% by weight or more and 10% by weight or less. When the proportion of the fine particles is within the above range, the dispersion stability of the phosphor 1 in the phosphor layer 2 (in the resin 14) can be improved, and as a result, the color reproducibility of the phosphor sheet 4 is improved. And high luminous flux and high durability can be achieved at the same time.

The contents of the phosphor 1, the resin 14, and the silicone fine particles in the phosphor layer 2 in the present invention can also be obtained from the produced phosphor layer 2 and the LED light emitter on which the phosphor layer 2 is mounted. For example, the phosphor layer 2 is embedded in a predetermined resin and cut to prepare a sample having a polished cross section, and the exposed cross section is observed with a scanning electron microscope (SEM) in the phosphor layer 2. It is possible to clearly distinguish the particle portion of the phosphor 1, the portion of the silicone fine particles, and the portion of the resin 14 in the above. From the area ratio of the cross-sectional image, it is possible to accurately measure each volume ratio of the phosphor 1 (fluorescent particle), the silicone fine particles, and the resin 14 in the entire phosphor layer 2. When the specific gravity of each component forming the phosphor layer 2 is clear, the weight ratio of the phosphor 1 to the phosphor layer 2 can be calculated by dividing each of these volume ratios by the respective specific gravity. .. When the composition of each component forming the phosphor layer 2 is not clear, the composition of each component can be determined by analyzing the cross section of the phosphor layer 2 by high-resolution micro-infrared spectroscopy or IPC emission analysis. .. If the composition of each of these components is clarified, the specific gravity peculiar to the substance of the resin 14 and the phosphor 1 can be estimated with considerable accuracy, and the above weight ratio can be obtained using this.

(Other ingredients)
It is preferable to add a hydrosilylation reaction retarder to the phosphor layer 2 as another component in order to suppress curing at room temperature and prolong the pot life. Examples of the hydrosilylation reaction retarder include 3-methyl-1-butyne-3-ol, 3,5-dimethyl-1-hexin-3-ol, phenylbutynol, 1-ethynyl-1-cyclohexanol and the like. Alkyne derivatives with carbon-carbon triple bonds, enein compounds such as 3-methyl-3-pentene-1-in, 3,5-dimethyl-3-hexene-1-in, tetramethyltetravinylcyclotetrasiloxane, tetramethyl Alkyne group-containing low molecular weight siloxane such as tetrahexenylcyclotetrasiloxane, methyl-tris (3-methyl-1-butyne-3-oxy) silane, vinyl-tris (3-methyl-1-butin-3-oxy) silane, etc. Alkyne-containing silane and the like.

Further, in the phosphor layer 2, as long as the effect of the present invention is not impaired, fine particles such as fumed silica, glass powder and quartz powder, inorganic fillers and pigments such as zinc oxide, and flame retardants can be added to the phosphor layer 2. A heat-resistant agent, an antioxidant, a dispersant, a solvent, an adhesive-imparting agent such as a silane coupling agent or a titanium coupling agent, or the like may be blended.

<Transparent resin layer>
The transparent resin layer 5 (see FIG. 1B) is a resin layer having a total light transmittance of 90% or more at a wavelength of 450 nm and does not contain the phosphor 1. The transparent resin layer 5 is laminated on the phosphor layer 2 as shown in FIG. 1B, for example. Further, the minimum transmittance of the transparent resin layer 5 at a wavelength of 400 nm to 800 nm is preferably 80% or more. The minimum transmittance referred to here is the smallest value among the light transmittances at wavelengths of 400 nm to 800 nm. When the minimum transmittance is 80% or more, the phosphor sheet 4 can easily achieve both high luminous flux and high durability. By having the transparent resin layer 5 on the phosphor layer 2, the durability of the phosphor 1 (for example, a red phosphor or the like) in the phosphor layer 2 is improved, and as a result, the durability as the phosphor sheet 4 is improved. Is improved.

Further, the transparent resin layer 5 may further contain fine particles. Since the transparent resin layer 5 contains fine particles, the film thickness uniformity of the transparent resin layer 5 is improved, so that the phosphor sheet 4 can be accurately picked up in the step of picking up the phosphor sheet 4 described later. .. One of the causes of the non-uniform film thickness of the transparent resin layer 5 is the flow of the resin in the drying step during the formation of the transparent resin layer 5. In this drying step, the resin contained in the transparent resin layer 5 is heated to reduce its viscosity, so that it becomes easy to flow. In particular, when the resin contained in the transparent resin layer 5 is a silicone resin having heat-sealing properties, the viscosity of the resin is significantly reduced, so that the film thickness of the transparent resin layer 5 tends to be non-uniform. When a heat-fusing silicone resin is used for the transparent resin layer 5, it is particularly important that the transparent resin layer 5 contains fine particles in order to maintain the uniformity of the film thickness of the transparent resin layer 5.

Improving the uniformity of the film thickness of the transparent resin layer 5 also has the effect of enhancing the function of the transparent resin layer 5 as a protective layer. When there is a locally thin portion of the transparent resin layer 5, this thin portion does not sufficiently function as a protective layer, so that the durability of the obtained illuminant is inferior. According to the present invention, such a situation can be suppressed.

(resin)
Examples of the resin used for the transparent resin layer 5 include silicone resin, fluororesin, epoxy resin, polyarylate resin, PET-modified polyarylate resin, polycarbonate resin, cyclic olefin resin, polyethylene terephthalate resin, polymethylmethacrylate resin, and polypropylene resin. It is preferably one or more kinds of resins selected from modified acrylic resin, polystyrene resin and acrylic nitrile / styrene copolymer resin. Among them, one or more kinds of resins selected from silicone resin, fluororesin, and epoxy resin are more preferable, and silicone resin is particularly preferable from the viewpoint of heat resistance.

When the resin used for the transparent resin layer 5 is a silicone resin, the silicone resin may have heat-sealing properties. Since this silicone resin has heat-sealing properties, when the transparent resin layer 5 is formed by the transparent resin sheet method described later, the phosphor layer 2 and the transparent resin layer 5 can be firmly adhered to each other.

(Fine particles)
The fine particles used in the transparent resin layer 5 preferably have low absorption or light emission in visible light. Examples of the fine particles include fine particles such as titania, silica, alumina, silicone, zirconia, ceria, aluminum nitride, silicon carbide, silicon nitride, and barium titanate. Of these, one or more fine particles selected from silica fine particles, alumina fine particles, and silicone fine particles are more preferable from the viewpoint of easy availability, and silicone fine particles are particularly preferable from the viewpoint of easy control of the refractive index and particle size. ..

By reducing the particle size of the fine particles in the transparent resin layer 5 and reducing the difference in refractive index between the resin and the fine particles in the transparent resin layer 5, the minimum transmittance of the transparent resin layer 5 at a wavelength of 400 nm to 800 nm can be reduced. It can be 80% or more.

The average particle size of the fine particles contained in the transparent resin layer 5 is preferably 1 nm or more, and more preferably 3 nm or more. The average particle size of the fine particles is preferably 1000 nm or less, more preferably 300 nm or less. When the average particle size of the fine particles is at least a preferable lower limit value, the fine particles can be stably dispersed in the transparent resin layer 5. When the average particle size of the fine particles is 1000 nm or less, the scattering of light in the transparent resin layer 5 can be suppressed, so that the high light transmittance of the transparent resin layer 5 can be maintained.

The average particle size of the fine particles (fine particles contained in the transparent resin layer 5) referred to here is the median diameter (D50). The average particle size of the fine particles can be determined by the same method as the average particle size of the red phosphor as the phosphor 1 described above.

The ratio of the fine particles to the total solid content in the transparent resin layer 5 is preferably 0.1% by weight or more, and more preferably 1% by weight or more. The proportion of the fine particles is preferably 30% by weight or less, and more preferably 10% by weight or more. When the proportion of the fine particles is at least a preferable lower limit value, it is possible to suppress variations in the film thickness of the transparent resin layer 5. When the proportion of the fine particles is not more than the preferable upper limit value, the high light transmittance of the transparent resin layer 5 can be maintained.

(Other features)
The light transmittance of the transparent resin layer 5 containing fine particles can be measured using a spectrophotometer. For example, when a U-4100 Spectrophotometer manufactured by Hitachi, Ltd. is used, the light transmittance of the sample of the transparent resin layer 5 can be measured with a basic configuration using an integrating sphere attached to this measuring device. Regarding the measurement conditions of this light transmittance, the slit is 2 nm and the scanning speed is 600 nm / min.

A sample for measuring the light transmittance of the transparent resin layer 5 (hereinafter, referred to as “transmittance measurement sample”) can be produced by the following method. For example, the resin and fine particles used in the transparent resin layer 5 are stirred and defoamed to prepare a dispersion, which is applied onto quartz glass with a blade coater and then heated in an oven at 150 ° C. for 1 hour. In this way, the transmittance measurement sample can be prepared.

The film thickness of the transmittance measurement sample can be measured by the following method. For example, the thickness of a predetermined position of quartz glass is measured in advance with a micrometer, and the measured position is marked. Then, after forming a transmittance measurement sample of the transparent resin layer 5 on the quartz glass by the above method, the thickness of the marking portion is measured again with a micrometer. The film thickness of this transmittance measurement sample can be obtained by subtracting the previously measured thickness of the quartz glass from the obtained thickness.

The difference in refractive index between the resin contained in the transparent resin layer 5 and the fine particles is preferably 0.5 or less, more preferably 0.3 or less, and particularly preferably 0.1 or less. The refractive index of the resin contained in the transparent resin layer 5 is preferably 1.3 or more, and preferably 1.6 or less. When the refractive index of this resin is 1.3 or more, the difference in refractive index between the transparent resin layer 5 and the phosphor layer 2 becomes relatively small, so that the light extraction efficiency from the phosphor layer 2 to the transparent resin layer 5 is relatively small. Can be improved. Further, since the refractive index of this resin is 1.6 or less, the difference in refractive index between the transparent resin layer 5 and the air layer becomes relatively small, so that the efficiency of light extraction from the transparent resin layer 5 to the air layer is improved. Can be made to. Further, from the viewpoint of further improving the light extraction efficiency, the refractive index of the resin contained in the transparent resin layer 5 is preferably equal to or lower than the refractive index of the resin contained in the phosphor layer 2.

The refractive index of the resin contained in the transparent resin layer 5 is measured by measuring the refractive index of the refractive index measurement sample using the refractive index / film thickness measuring device “Prism Coupler MODEL2010 / M” (manufactured by Metricon). can do. For the refractive index measurement sample, this resin was stirred and defoamed at 1000 rpm for 10 minutes using a planetary stirring defoaming device "Mazelstar KK-400" manufactured by Kurabou Co., Ltd. to prepare a dispersion, and this dispersion was used as PET. It can be obtained by dropping 5 cc onto the film and then heating it in an oven at 150 ° C. for 1 hour.

<Other layers>
The phosphor sheet 4 according to the embodiment of the present invention may be provided with a different phosphor layer or diffusion layer different from the phosphor layer 2 on at least one of the upper and lower sides of the phosphor layer 2. In this case, the transparent resin layer formed under the fluorescent layer 2 or another fluorescent layer (for example, between one of the fluorescent layers and the surface of the LED chip) does not use an adhesive on the LED chip. It is preferable to have heat-sealing properties so that it can be attached to. When the above transparent resin layer is attached to the surface of an LED chip such as GaN or sapphire having a high refractive index, the refractive index of the surface of the LED chip and the transparent resin layer located under any of the phosphor layers The smaller the difference in refractive index, the more efficient the light extraction from the surface of the LED chip to the transparent resin layer can be improved. Therefore, in this case, the refractive index of this transparent resin layer is preferably 1.56 or more.

The diffusion layer is a layer containing a predetermined resin and a diffusion material such as silica, titania, and zirconia. By forming the diffusion layer, the directivity of the emitted light can be weakened, and a more isotropic emitted light can be obtained. Therefore, the diffusion layer is preferably formed on the upper layer of the phosphor layer 2.

<Method of producing fluorescent sheet>
Next, the method for producing the fluorescent material sheet 4 according to the embodiment of the present invention will be described in detail. The production method described below is an example, and the production method of the phosphor sheet 4 is not limited to this.

As one method for producing the phosphor sheet 4, there is a method in which the phosphor layer 2 is directly applied onto the support 3. In this method, first, as a coating liquid for forming the fluorescent material layer 2, a solution in which the fluorescent material 1 is dispersed in the resin 14 (hereinafter, referred to as “resin liquid for producing the fluorescent material layer”) is prepared. The resin solution for producing a phosphor layer is obtained by mixing the phosphor 1 and the resin 14 in a solvent.

When it is necessary to add a solvent to adjust the viscosity, the type of the solvent is not particularly limited as long as the viscosity of the resin 14 in the fluid state can be adjusted. Examples of the solvent include toluene, methyl ethyl ketone, methyl isobutyl ketone, hexane, heptane, cyclohexane, acetone, terpineol, butyl carbitol, butyl carbitol acetate, glyme, jigglime, propylene glycol monomethyl ether, propylene glycol monomethyl ether acetate and the like. Can be mentioned.

After the components necessary for forming the phosphor layer 2 and the components such as a solvent added as necessary are prepared so as to have a predetermined composition, the mixture of these components is mixed with a homogenizer and a self-revolving stirrer. A resin solution for producing a phosphor layer can be obtained by uniformly mixing and dispersing with a stirring / kneading machine such as a three-roller, a ball mill, a planetary ball mill, or a bead mill. After this mixing and dispersion, or in the process of this mixing and dispersion, defoaming under vacuum or reduced pressure conditions is also preferably performed.

However, the Mn-activated double-fluoride complex phosphor as the phosphor 1 has the property of having lower hardness and brittleness as compared with a phosphor produced by firing at a high temperature such as a β-type sialon phosphor. Therefore, when the Mn-activated bifluoride complex phosphor is dispersed by a stirrer / kneader or the like, the Mn-activated compound by setting the dispersion conditions so that the impact applied to the Mn-activated compound fluoride complex phosphor is as small as possible. It is preferable to suppress the crushing of the fluoride complex phosphor. By suppressing the crushing of the Mn-activated difluoride complex phosphor, a phosphor sheet 4 having a strong emission intensity can be obtained.

Next, the resin solution for producing a phosphor layer prepared as described above is applied onto the support 3 and dried. The phosphor layer 2 thus obtained on the support 3 is heat-cured to produce it. The application of the resin solution for forming the phosphor layer on the support 3 is a reverse roll coater, a blade coater, a slit die coater, a direct gravure coater, an offset gravure coater, a kiss coater, screen printing, a natural roll coater, an air knife coater, and a roll. It can be performed by a blade coater, a toe stream coater, a rod coater, a wire bar coater, an applicator, a dip coater, a curtain coater, a spin coater, a knife coater, or the like. In order to obtain the uniformity of the film thickness of the phosphor layer 2, it is preferable to apply with a slit die coater. The phosphor layer 2 can also be produced by using a printing method such as screen printing, gravure printing, or lithographic printing. In particular, screen printing is preferably used.

The resin solution for producing the phosphor layer can be dried by using a general heating device such as a hot air dryer or an infrared dryer. A general heating device such as a hot air dryer or an infrared dryer is used for heat curing of the phosphor layer 2. In this case, the heat curing conditions are usually 40 ° C. to 250 ° C. for 1 minute to 5 hours, preferably 100 ° C. to 200 ° C. for 2 minutes to 3 hours.

By the method described above, the phosphor sheet 4 provided with at least the phosphor layer 2 can be produced. As illustrated in FIG. 1A, the phosphor sheet 4 is in a state of being supported by the support 3 by itself.

The support 3 used in the present invention is not particularly limited, and examples thereof include known metals, resin films, glass, ceramics, paper, and cellulose acetate. Of these, glass or a resin film is preferably used because of the ease of producing the fluorescent material sheet 4 and the ease of individualizing the fluorescent material sheet 4. In particular, the support 3 is preferably in the form of a flexible film from the viewpoint of adhesion when the phosphor sheet 4 is attached to the LED chip. Further, a film having high strength is preferable as the support 3 so that there is no risk of breakage when handling the film-shaped support 3. A resin film is preferable as the support 3 from the viewpoints of these required characteristics and economic efficiency. Among the resin films used as the support 3, a plastic film selected from the group consisting of polyethylene terephthalate, polyphenylene sulfide, polypropylene, and polyimide is preferable from the viewpoint of economy and handleability. Further, when a high temperature of 200 ° C. or higher is required when drying the resin solution for producing the phosphor layer or when attaching the phosphor sheet 4 to the LED chip, a polyimide film is preferable from the viewpoint of heat resistance. The surface of the support 3 may be mold-released in advance because the phosphor sheet 4 can be easily peeled off from the support 3.

Further, in the method for producing the fluorescent material sheet 4, when the transparent resin layer 5 is formed on the fluorescent material layer 2, there are a direct coating method and a transparent resin sheet method as a method for forming the transparent resin layer 5. In the direct coating method, for example, a resin solution whose viscosity has been adjusted with a transparent resin solvent for producing the transparent resin layer 5 (hereinafter, referred to as “resin solution for producing transparent resin layer”) is directly applied onto the phosphor layer 2. After that, it is a method of performing drying and heat curing treatment.

In the direct coating method, the same method as in the production of the phosphor layer 2 (application of the resin solution for producing the phosphor layer) can be used for coating the resin solution for producing the transparent resin layer, but the film of the transparent resin layer 5 is used. In order to obtain thickness uniformity, it is preferable to apply a resin solution for producing a transparent resin layer with a slit die coater. The resin liquid for producing the transparent resin layer can be dried by using a general heating device such as a hot air dryer or an infrared dryer. A general heating device such as a hot air dryer or an infrared dryer is used for heat curing of the transparent resin layer 5 formed by this drying. In this case, the heat curing conditions are usually 40 ° C. to 250 ° C. for 1 minute to 5 hours, preferably 100 ° C. to 200 ° C. for 2 minutes to 3 hours.

In the transparent resin sheet method, a transparent resin sheet is produced, and the phosphor layer 2 side of the phosphor sheet 4 and the transparent resin layer 5 side of the produced transparent resin sheet are bonded to each other on the phosphor layer 2. This is a method for forming the transparent resin layer 5. The transparent resin sheet can be produced by the same method as the fluorescent material sheet 4 provided with the fluorescent material layer 2 described above. That is, by using a "resin liquid for producing a transparent resin layer" instead of the "resin liquid for producing a fluorescent material layer", the same method as the above-mentioned method for producing a fluorescent material sheet 4 is performed, and a predetermined support (for example, a support) is performed. A transparent resin sheet can be produced by forming the transparent resin layer 5 on the body 3).

When the transparent resin layer 5 is formed on the phosphor layer 2 by the transparent resin sheet method, the resin of at least one of the phosphor layer 2 and the transparent resin layer 5 needs to be in a semi-cured state. When the resin of at least one layer is in a semi-cured state, the phosphor layer 2 and the transparent resin layer 5 can be adhered to each other. In this transparent resin sheet method, it is more preferable that at least the resin of the transparent resin layer 5 is semi-cured, and both the resin 14 of the phosphor layer 2 and the resin of the transparent resin layer 5 are in a semi-cured state. Especially preferable.

The phosphor layer 2 and the transparent resin layer 5 are preferably bonded by heating. By heating, the viscosities of the resins of the phosphor layer 2 and the transparent resin layer 5 are lowered, so that the phosphor layer 2 and the transparent resin layer 5 can be firmly bonded to each other. In order to sufficiently reduce the viscosity of each resin at the time of bonding, the heating conditions are preferably 40 ° C. or higher, more preferably 60 ° C. or higher, and particularly preferably 80 ° C. or higher. Further, if the temperature of each resin at the time of bonding is too high, the semi-cured resin (for example, the resin of the transparent resin layer 5) is cured before the phosphor layer 2 and the transparent resin layer 5 are adhered to each other. Therefore, it becomes difficult for the phosphor layer 2 and the transparent resin layer 5 to adhere to each other. From the viewpoint of suppressing thermosetting at the time of bonding, the heating conditions are preferably 200 ° C. or lower, more preferably 170 ° C. or lower, and particularly preferably 150 ° C. or lower.

Further, when the phosphor layer 2 and the transparent resin layer 5 bite air bubbles at the time of bonding, light is diffusely reflected at the interface between the air bubbles and the phosphor layer 2 and the interface between the air bubbles and the transparent resin layer 5. .. As a result, the efficiency of extracting light from the phosphor sheet 4 is lowered, and as a result, the brightness of the light emitting body manufactured by using the phosphor sheet 4 is lowered. From the viewpoint of preventing such bubble biting, the phosphor layer 2 and the transparent resin layer 5 are preferably bonded in a vacuum atmosphere. The vacuum atmosphere is an atmosphere in which the pressure is equal to or less than a predetermined value. The pressure in this vacuum atmosphere is 100 hPa or less, more preferably 10 hPa or less, further preferably 5 hPa or less, and particularly preferably 1 hPa or less.

(Manufacturing method of luminous body using phosphor sheet)
A method for producing a luminescent material according to an embodiment of the present invention (a method for producing a luminescent material using the phosphor sheet 4) will be described. FIG. 2 is a process diagram showing an example of a method for manufacturing a light emitter using a phosphor sheet according to an embodiment of the present invention. The following description is an example, and the method for producing a luminescent material according to the embodiment of the present invention is not limited to the one described below.

The method for producing a light emitting body using the phosphor sheet 4 includes roughly three steps. The first step is an individualization step of individualizing the phosphor sheet 4. The second step is a pick-up step of picking up the individualized phosphor sheet 4. The third step is a sticking step of sticking the picked-up phosphor sheet 4 (which has been individualized by the individualization step) to the light source. In addition, the method for producing the luminescent material may include other steps, if necessary.

Hereinafter, the phosphor sheet 4 is composed of a phosphor layer 2 formed on the support 3, and the phosphor layer 2 as the phosphor sheet 4 is separated into individual pieces to form an LED chip which is an example of a light source. A method for producing a light emitting body according to an embodiment of the present invention will be described with reference to FIG.

(Individualization process)
In the individualization step, the fluorescent material sheet 4 can be individualized by a method such as punching with a die, processing with a laser, dicing or cutting. At this time, the phosphor layer 2 as the phosphor sheet 4 may be in a semi-cured state or may be pre-cured. Since high energy is applied to the phosphor layer 2 in the laser processing, the resin of the phosphor layer 2 (for example, the resin 14 shown in FIG. 1A) is burnt or the phosphor (for example, the phosphor 1 shown in FIG. 1A) is deteriorated. Is very difficult to avoid. Therefore, as a method for individualizing the phosphor sheet 4, cutting or cutting with a cutting tool is desirable.

For example, as shown in FIG. 2, the phosphor layer 2 as the phosphor sheet 4 is in a state of being supported by the support 3. In the individualization step, the phosphor layer 2 on the support 3 is cut by the blade 6 (state S1). As a result, the phosphor layer 2 is fragmented into a plurality of pieces and processed into the fragmented phosphor layer 7 (state S2). At this time, the individualized phosphor layer 7 remains attached to the support 3.

The blade 6 is, for example, a rotary blade. As a device for cutting the phosphor layer 2 with a rotary blade, a device called a dicer, which is used for cutting (dicing) a semiconductor substrate into individual chips, can be preferably used. If a dicer is used, the width of the dividing line of the phosphor layer 2 can be precisely controlled by setting the thickness and conditions of the rotary blade, so that processing accuracy higher than that of cutting the phosphor layer 2 by pushing a simple blade can be obtained. .. In any of these cutting methods, the phosphor layer 2 may be individualized together with the support 3. Alternatively, the support 3 may not be cut while the phosphor layer 2 is individualized. At this time, it is preferable to perform a so-called half-cut on the support 3 so that a notch line that does not penetrate is inserted.

In the individualization step, the fluorescence layer 2 is preferably cut by dry cutting. Dry cutting is a cutting method that does not use a liquid such as water when cutting. The cutting of the phosphor layer 2 in the individualization step is not limited to this, and examples thereof include cutting with a Thomson blade. When the phosphor layer 2 contains a phosphor whose luminous efficiency is lowered by reacting with water, such as _{K 2} SiF _{6: Mn, dry cut is particularly effective.}

The phosphor sheet 4 may be subjected to perforation processing of the phosphor layer 2 before and after the individualization step or at the same time as the individualization step. As the drilling process, known methods such as laser processing and punching with a die can be preferably used. However, since laser processing causes burning of the resin of the phosphor layer 2 and deterioration of the phosphor, punching with a die is performed. Processing is more desirable.

(Pickup process)
The phosphor sheet 4 that has been individualized by the above-mentioned individualization step is picked up by a pickup step that is the next step of the individualization step. For example, as shown in FIG. 2, the individualized phosphor layer 7 is in a state of being attached on the support 3. In the pick-up step, the individualized phosphor layer 7 is peeled off from the support 3 and picked up by a pick-up device (not shown) provided with a suction device such as a collet 8 (state S3).

(Attachment process)
The individualized phosphor layer 7 (an example of the individualized phosphor sheet 4) picked up by the above-mentioned pickup step is attached to the light source by the attachment step which is the next step of the pickup step. For example, as shown in FIG. 2, the individualized phosphor layer 7 is in a state of being picked up by the collet 8. The collet 8 is conveyed together with the individualized phosphor layer 7 to the position of the LED chip 9 (an example of a light source) mounted on the substrate 11, whereby the light extraction surface of the LED chip 9 and the individualized phosphor layer 7 are conveyed. Is opposed to the adhesive surface (for example, the lower surface) of. Next, the collet 8 is attached by pressing the adhesive surface of the individualized phosphor layer 7 against the light extraction surface of the LED chip 9 (state S4). At this time, the reflector 10 may be formed around the LED chip 9 on the substrate 11.

It is preferable to use an adhesive (not shown) for sticking the individualized phosphor layer 7 and the LED chip 9 in the sticking step. As this adhesive, a known die bond agent or adhesive can be used. For example, acrylic resin-based, epoxy resin-based, urethane resin-based, silicone resin-based, modified silicone resin-based, phenol resin-based, polyimide-based, polyvinyl alcohol-based, polymethacrylate resin-based, melamine resin-based, and urea resin-based adhesives. Can be used. When the phosphor layer 2 has adhesiveness, the individualized phosphor layer 7 and the LED chip 9 may be attached by utilizing this adhesiveness.

Further, when the sticking step is a step of heating the individual phosphor layer 7 and sticking it to the LED chip 9, when this sticking step is performed in the air, between the LED chip 9 and the individual phosphor layer 7. May bite air bubbles into the LED. When a bubble is bitten, light is diffusely reflected at the interface between the bubble and the LED chip 9 and the interface between the bubble and the individualized phosphor layer 7. As a result, the efficiency of extracting light from the LED chip 9 is lowered, and as a result, the brightness of the light emitter (for example, the light emitter 13 shown in FIG. 2) manufactured by using the phosphor sheet 4 is lowered. From the viewpoint of preventing such bubble biting, it is preferable to perform this sticking step in a vacuum atmosphere.

(Other processes)
As another step, the above-described method for manufacturing a light emitter may further include a connection step of electrically connecting the LED chip 9 and the substrate 11 which is an example of a circuit board. In this connection step, the electrodes of the LED chip 9 and the wiring of the substrate 11 are electrically connected by a known method. Thereby, the light emitting body 13 can be obtained. When the LED chip 9 has an electrode on the light extraction surface side, the electrode on the upper surface of the LED chip 9 and the wiring of the substrate 11 are connected by wire bonding. When the LED chip 9 is a flip chip type having an electrode pad on the opposite surface of the light emitting surface, the electrode surface of the LED chip 9 is made to face the wiring of the substrate 11, and these are connected by batch joining. In this case, the connection between the substrate 11 and the LED chip 9 may be performed before the individualized phosphor sheet 4 (for example, the individualized fluorescent material layer 7) is attached.

When the individual phosphor layer 7 is attached to the LED chip 9 in a semi-cured state, the individual phosphor layer 7 can be cured at a suitable timing before or after the above-mentioned connection step. For example, when thermocompression bonding is performed so that the flip-chip type LED chip 9 is collectively bonded to the substrate 11, the individualized phosphor layer 7 may be cured at the same time by the heating. Further, when the package in which the LED chip 9 and the substrate 11 are connected is surface-mounted on a larger circuit board, the individualized phosphor layer 7 may be cured at the same time as soldering by solder reflow. ..

When the individualized fluorescent layer 7 is attached to the LED chip 9 in a cured state, after the individualized fluorescent layer 7 and the LED chip 9 are attached, the individualized fluorescent layer 7 is attached. There is no need to provide a curing process. The case where the individualized phosphor layer 7 is attached to the LED chip 9 in a cured state is, for example, the case where a separate adhesive layer is formed on the cured individualized phosphor layer 7, or the individualized fluorescence. This is the case where the body layer 7 has heat-sealing properties after curing.

In addition, the above-mentioned method for manufacturing a light emitting body may further include a sealing step for sealing the LED chip 9 after the sticking step is performed, as another step. For example, as shown in FIG. 2, in the sealing step, the transparent sealing material 12 is placed on the substrate 11 (specifically, the reflector) so as to cover the LED chip 9 after the individualized phosphor layer 7 is attached. It is injected into (inside 10). As a result, the LED chip 9 is sealed by the transparent sealing material 12 (state S5). In this way, the light emitting body 13 as shown in FIG. 2 is produced. As the transparent sealing material 12, a silicone resin is preferably used from the viewpoint of transparency and heat resistance.

As described above, in the method for producing a light emitter described with reference to FIG. 2, the case where the phosphor sheet 4 is composed of the phosphor layer 2 on the support 3 has been illustrated, but the method for producing this light emitter is the same. It is not limited to. That is, the phosphor sheet 4 used in the method for producing the luminescent material may be composed of the phosphor layer 2, or the phosphor layer 2 and the transparent resin layer 5 as illustrated in FIG. 1B. It may be made of a laminated body, or may be further provided with other layers such as the above-mentioned diffusion layer. For example, when the phosphor sheet 4 includes the phosphor layer 2 and the transparent resin layer 5, in the individualization step, both the fluorescent layer 2 and the transparent resin layer 5 on the support 3 are individualized. .. In the pick-up step, the individualized laminate of the phosphor layer 2 and the transparent resin layer 5 is picked up from the support 3. In the sticking step, the picked-up laminate (individualized) is stuck on the light extraction surface of the LED chip 9.

<Luminometer, light source unit, display>
The light emitting body according to the embodiment of the present invention includes the above-mentioned phosphor sheet 4. For example, the light emitter 13 shown in FIG. 2 includes an individualized phosphor layer 7 as a phosphor sheet 4 on the light extraction surface of the LED chip 9. Such a light emitter can be widely applied to in-vehicle headlights, backlights of televisions and smartphones, lighting and the like. In the present invention, the phosphor sheet 4 and the light emitter using the phosphor sheet 4 are excellent in improving color reproducibility, have high luminous flux, and have high durability, and therefore are preferably applied to a light source unit such as a backlight.

The light source unit according to the embodiment of the present invention includes the above-mentioned phosphor sheet 4. The light source unit also includes a light source having a phosphor sheet 4. Such a light source unit can be applied to displays for televisions, smartphones, tablet computers, and game machines.

The display according to the embodiment of the present invention includes a light source unit having the above-mentioned phosphor sheet 4. This display also includes a display provided with a light source unit having a light emitting body (a light emitting body produced by using the phosphor sheet 4) according to the present invention. Examples of such a display include a liquid crystal display and the like.

<Color reproduction range measurement>
The color reproduction range of the liquid crystal display when the light emitter produced by using the phosphor sheet 4 is used as the backlight of the liquid crystal display can be evaluated by the DCI ratio. The DCI ratio is an area ratio in the chromaticity region when the area of the DCI chromaticity region according to the DCI (Digital Cinema Initiative) standard is used as a reference (100%). The DCI ratio can be measured by the following procedure.

First, a color filter that transmits red light produced by a known method is placed on the produced illuminant, and 1 W of power is applied to the illuminant to light the illuminant to light the total luminous flux measurement system (HM). -Measure the chromaticity of the emitted light using (3000, manufactured by Otsuka Electronics Co., Ltd.). Similarly, the chromaticity of the emitted light is measured for each of the case where the color filter that transmits green light is placed on the illuminant and the case where the color filter that transmits blue light is placed. The DCI ratio can be calculated by dividing the area of the triangle having the obtained three chromaticities as the vertices by the area of the DCI chromaticity region.

Hereinafter, the present invention will be specifically described with reference to Examples. However, the present invention is not limited thereto.

<Silicone resin>
The silicone resin T11 is OE-6351A / B (manufactured by Toray Dow Corning Co., Ltd.). The refractive index of the silicone resin T11 is 1.41. The silicone resin T12 is KER6075LV A / B (manufactured by Shin-Etsu Chemical Co., Ltd.). The refractive index of the silicone resin T12 is 1.45. The silicone resin T13 is XE14-C2860 (manufactured by Momentive Performance Materials Inc.). The refractive index of the silicone resin T13 is 1.50. Silicone resin T14 is OE6630 A / B (manufactured by Toray Dow Corning Co., Ltd.). The refractive index of the silicone resin T14 is 1.53.

The silicone resin T15 contains 75 parts by weight of the following component (E), 10 parts by weight of the component (F), 25 parts by weight of the component (G), 0.025 parts by weight of the reaction inhibitor, and 0.01 parts by weight of the platinum catalyst. Obtained by mixing by weight. The transparent resin sheet produced using the silicone resin T15 had a storage elastic modulus of 1 MPa at 25 ° C. and a storage elastic modulus of 0.01 MPa at 100 ° C., and exhibited good heat-sealing properties. The refractive index of the silicone resin T15 is 1.56.

In the silicone resin T15, the component (E) is (MeViSiO _2/2 ) _0.25 (Ph ₂ SiO _2/2 ) _0.3 (PhSiO _3/2 ) _0.45 (HO _1/2 ) _0.03 . The component (F) is ViMe ₂ SiO (MePhSiO) _17.5 SiMe ₂ Vi. The component (G) is (HMe ₂ SiO) ₂ SiPh ₂ . However, Me is a methyl group, Vi is a vinyl group, and Ph is a phenyl group. The reaction inhibitor is 1-ethynylhexanol. The platinum catalyst is a 1,3-divinyl-1,1,3,3-tetramethyldisiloxane solution of platinum-1,3-divinyl-1,1,3,3-tetramethyldisiloxane complex. The platinum content of this solution is 5% by weight.

Silicone resin T16 was obtained by the following preparation method. The refractive index of the silicone resin T16 is 1.60.

In the method for preparing the silicone resin T16, 1-naphthyltrimethoxysilane (892.8 g) and 1,3-divinyl-1,3-diphenyldimethyldisiloxane (372.0 g) were added to the reaction vessel and mixed in advance. After that, trifluoromethanesulfonic acid (6.15 g) was added, water (213.84 g) was added under stirring, and heating and refluxing was performed for 2 hours. Then, atmospheric pressure distillation was performed until the temperature reached 85 ° C. Then, toluene (435.6 g) and potassium hydroxide (3.28 g) were added, and the mixture was distilled under normal pressure under heating until the reaction temperature reached 120 ° C., and the reaction was carried out at this temperature for 6 hours. Then, the mixture was cooled to room temperature, acetic acid (3.524 g) was added, and the mixture was neutralized. After the produced salt is filtered off, the low boiling point is distilled off from the obtained transparent solution by heating under reduced pressure, and the average unit formula: (MePhViSiO _1/2 ) _0.40 (NaphSiO _3/2 ) _0.60. 957.4 g of polysiloxane resin P1 was obtained.

Further, 1-naphthyltrimethoxysilane (50 g) was added to the reaction vessel, and the mixture was heated and melted, and then trifluoromethanesulfonic acid (0.06 g) was added. Then, acetic acid (9.3 g) was added dropwise while heating at 45 ° C. to 50 ° C. After completion of the dropping, the mixture was heated and stirred at 50 ° C. for 30 minutes. The low boiling point was distilled off under normal pressure under heating until the reaction temperature reached 80 ° C. Then, the mixture was cooled to room temperature, 1,3,3-tetramethyldisiloxane (4.4 g) was added dropwise, and the mixture was heated until the reaction temperature reached 45 ° C. Then, acetic acid (18 g) was added dropwise at 45 ° C to 50 ° C. After completion of the dropping, the mixture was heated and stirred at 50 ° C. for 30 minutes. Acetic anhydride (15.5 g) was added dropwise while maintaining the temperature at 60 ° C. or lower by air cooling or water cooling, and after completion of the addition, heating and stirring was performed at 50 ° C. for 30 minutes. Next, toluene and water were added, and stirring, standing, and extraction of the lower layer were repeated, and washing with water was performed. After confirming that the pH of the lower layer is 7, the low boiling point substance is distilled off under reduced pressure by heating from the toluene layer which is the upper layer, and the average unit formula: (HMe ₂ SiO _1/2 ) _0.60 (NaphSiO _3/2 ) _0.40 43 g of a colorless transparent liquid organopolysiloxane P2 represented by is obtained.

52.0 parts by mass of organopolysiloxane resin P1, 30.0 parts by mass of organopolysiloxane P2, 14.0 parts by mass of organotrisiloxane represented by _{the formula: HMe 2} SiOPh ₂ SiOSiMe _{2 H, and platinum-1.} , 3-Divinyl-1,1,3,3-Tetramethyldisiloxane Complex 1,3,5,7-Tetramethyl-1,3,5,7-Tetravinylcyclotetrasiloxane solution (0. as platinum). A solution containing 1% by mass) was mixed in an amount of 0.25 parts by mass to prepare a curable silicone composition.

Silicone resin T17 was obtained by the following preparation method. The refractive index of the silicone resin T17 is 1.65.

In the preparation method of the silicone resin T17, methyltrimethoxysilane (16.6 g), phenyltrimethoxysilane (56.2 g), and "Optreak TR-527" having a number average particle size of 15 nm (trade name, Catalytic Chemical Industry Co., Ltd.) Composition: 20% by weight of titanium oxide particles, 80% by weight of methanol) (194 g), propylene glycol monomethyl ether acetate (126.9 g) was placed in a reaction vessel, and water (21.9 g) and phosphoric acid (21.9 g) and phosphoric acid (21.9 g) were added to this solution. 0.36 g) was added dropwise with stirring so that the reaction temperature did not exceed 40 ° C. After the dropping, a distillation apparatus was attached to the flask, and the obtained solution was heated and stirred at a bath temperature of 105 ° C. for 2.5 hours to react while distilling off the methanol produced by hydrolysis. Then, this solution was heated and stirred at a bath temperature of 115 ° C. for another 2 hours, and then cooled to room temperature to obtain titanium oxide particles grafted with polysiloxane.

Next, the obtained titanium oxide particles (50.00 g) are mixed with the silicone resin T14 (8.00 g), and a planetary stirring / defoaming device "Mazelstar KK-400" (manufactured by Kurabo) is used at 1000 rpm. The mixture was stirred and defoamed for 20 minutes to prepare a silicone resin T17. As a result of measuring the refractive index, the average refractive index of the silicone resin T17 was 1.65.

Silicone resin T18 was obtained by the following preparation method. The refractive index of the silicone resin T18 is 1.70.

In the method for preparing the silicone resin T18, the silicone resin T14 (3.0 g) is mixed with the titanium oxide particles (60.0 g) grafted with polysiloxane in the same manner as in the method for preparing the silicone resin T17 described above, and a planetary type is used. Using a stirring / defoaming device "Mazelstar KK-400" (manufactured by Kurabo), stirring / defoaming was performed at 1000 rpm for 20 minutes. As a result, the silicone resin T18 was produced. As a result of measuring the refractive index, the refractive index of the silicone resin T18 was 1.70.

<Fluororesin>
The fluororesin T21 is AF2400S (manufactured by Mitsui / DuPont Fluorochemical Co., Ltd.). The refractive index of the fluororesin T21 is 1.30. The fluororesin T22 is CTX-800 (CT-solv 180 solution) (manufactured by Asahi Glass Co., Ltd.). The refractive index of the fluororesin T22 is 1.35.

<Fluorescent material>
The green phosphor is a β-type sialon phosphor called GR-MW540K (manufactured by Denka Corporation). The yellow phosphor is a Ce-doped YAG phosphor called NYAG-02 (manufactured by Intematics). The red phosphor T1 is a KSF phosphor sample A (manufactured by Nemoto Lumimaterial Co., Ltd.). The red phosphor T2 is a KSF phosphor sample B (manufactured by Nemoto Lumimaterial Co., Ltd.). The red phosphor T3 is KSF phosphor sample C (manufactured by Nemoto Lumimaterial Co., Ltd.). The red phosphor T4 is a KSF phosphor sample D (manufactured by Nemoto Lumimaterial Co., Ltd.). The red phosphor T5 is a KSF phosphor sample E (manufactured by Nemoto Lumimaterial Co., Ltd.). The red phosphor T6 is a KSF phosphor sample F (manufactured by Nemoto Lumimaterial Co., Ltd.).

The red phosphors T1 to T6 D10, D50 and D90 used in this example were measured by the following methods. The measurement results are shown in Table 1. Table 1 also shows the value x calculated based on the above-mentioned formula (11) based on the measured D10, D50 and D90.

In the method for measuring D10, D50 and D90 of the red phosphors T1 to T6, a fluorescent sheet (for example, the fluorescent sheet 4 shown in FIGS. 1A and 1B) is prepared as described later, and the cross section of the fluorescent layer is SEM. In the two-dimensional image obtained by observing in, calculate the maximum distance between the two intersections of the straight line that intersects the outer edge of the particle at two points, and define it as the individual particle size of the particle. did. In the particle size distribution obtained from the individual particle sizes of all the observed particles, the particle size of 10% of the accumulated passages from the small particle size side is defined as D10, the particle size of 50% of the integrated passages is D50, and the integrated number of passages The particle size of 90% was defined as D90.

<Base film>
The base film is an example of the support for the fluorescent material sheet in the present invention (for example, the support 3 shown in FIGS. 1A and 1B). In this example, the base film was a PET film. This PET film is "Therapeutic" BX9 (manufactured by Toray Film Processing Co., Ltd.), and its film thickness is 50 μm.

<Silicone fine particles>
Silicone fine particles were obtained by the following production method.

In the method for producing silicone fine particles, a stirrer, a thermometer, a recirculation tube, and a dropping funnel are attached to a 2L four-necked round bottom flask, and the flask contains 10000 ppm of a polyether-modified siloxane "BYK333" as a surfactant, 2.5%. Ammonia water (2 L) of the above was added, and the temperature was raised by an oil bath while stirring at 300 rpm. When the internal temperature reached 50 ° C., a mixture (22/78 mol%) (200 g) of methyltrimethoxysilane and phenyltrimethoxysilane was added dropwise from the dropping funnel over 30 minutes. After continuing stirring for another 60 minutes at the same temperature, acetic acid (special grade reagent) (about 5 g) was added, and the mixture was stirred and mixed, and then filtered. Water (600 mL) was added twice and methanol (200 mL) was added once to the produced particles on the filter, and the particles were filtered and washed. The cake on the filter was taken out, crushed, and freeze-dried for 10 hours to obtain a white powder (40 g) as silicone fine particles.

When the obtained silicone fine particles were observed by SEM, it was confirmed that they were monodisperse spherical fine particles. As a result of calculating the average particle size of the silicone fine particles from the obtained SEM image, it was 50 nm. The refractive index of the silicone fine particles was measured by the immersion method and found to be 1.54. As a result of observing the silicone fine particles with a cross-sectional TEM, it was confirmed that the inside of the particles was fine particles having a single structure.

<Silica fine particles>
The silica fine particles T31 are Aerosil 200 (manufactured by Nippon Aerosil Co., Ltd.). The average particle size of the silica fine particles T31 is 12 nm. The refractive index of the silica fine particles T31 is 1.46. The silica fine particle T32 is "Admanano" YA050C (manufactured by Admatex Co., Ltd.). The average particle size of the silica fine particles T32 is 50 nm. The refractive index of the silica fine particles T32 is 1.46. The silica fine particle T33 is "Admanano" YA100C (manufactured by Admatex Co., Ltd.). The average particle size of the silica fine particles T33 is 100 nm. The refractive index of the silica fine particles T33 is 1.46. The silica fine particle T34 is "Admafine" SO-E1 (manufactured by Admatex Co., Ltd.). The average particle size of the silica fine particles T34 is 250 nm. The refractive index of the silica fine particles T34 is 1.46. The silica fine particle T35 is HPS-1000 (manufactured by Toagosei Corporation). The average particle size of the silica fine particles T35 is 1000 nm. The refractive index of the silica fine particles T35 is 1.46. The silica fine particle T36 is "Admafine" SO-E5 (manufactured by Admatex Co., Ltd.). The average particle size of the silica fine particles T36 is 1500 nm. The refractive index of the silica fine particles T36 is 1.46.

<Alumina fine particles>
The alumina fine particles are Aeroxide AluC (manufactured by Nippon Aerosil Co., Ltd.). The average particle size of the alumina fine particles is 12 nm. The refractive index of the alumina fine particles is 1.77.

<Titania fine particles>
The titania fine particles are MT-01 (manufactured by TAYCA CORPORATION). The average particle size of the titania fine particles is 10 nm. The refractive index of the titania fine particles is 2.50.

<Preparation of fluorescent sheet>
In the preparation of the phosphor sheet in this example, a silicone resin, silicone fine particles, a red phosphor, and a green phosphor were mixed in a polyethylene container having a volume of 300 mL in a predetermined ratio. Further, 8 wt% of toluene was added as a solvent, and the mixture was stirred and defoamed at 1000 rpm using a planetary stirring and defoaming device "Mazelstar KK-400" (manufactured by Kurabo Industries) to obtain a resin solution for producing a phosphor layer. .. Then, a resin solution for producing a fluorescent substance layer was applied onto a PET film using a slit die coater, and dried at 130 ° C. for 30 minutes to prepare a fluorescent substance layer to obtain a fluorescent substance sheet.

<Measurement of film thickness of phosphor layer>
In the film thickness measurement of the phosphor layer in this example, the thickness of the PET film for producing the phosphor layer at a predetermined position was measured in advance with a micrometer and marked. Then, a phosphor layer was formed on this PET film, and then the thickness of the marking portion was measured again with a micrometer. The film thickness of this phosphor layer was obtained by subtracting the previously measured thickness of the PET film from the obtained thickness. In this example, the film thickness was measured at 25 points in a grid pattern at 10 mm intervals, and the average value of these was taken as the film thickness of the phosphor layer.

<Formation of transparent resin layer by direct coating method>
In the formation of the transparent resin layer by the direct coating method in this example, a silicone resin, a fluororesin, and fine particles were mixed in a predetermined ratio in a polyethylene container having a volume of 300 mL. Further, 5 wt% of toluene was added as a solvent, and then, using a planetary stirring / defoaming device "Mazelstar KK-400" (manufactured by Kurabo), stirring / defoaming was performed at 1000 rpm for 20 minutes to prepare a transparent resin layer resin. Obtained liquid. Then, a resin solution for producing a transparent resin layer was applied onto the fluorescent material layer using a slit die coater, and dried at 130 ° C. for 30 minutes to form a transparent resin layer on the fluorescent material layer. As a result, a phosphor sheet having a transparent resin layer on the phosphor layer was obtained. Hereinafter, the "fluorescent sheet having a transparent resin layer on the phosphor layer" is appropriately referred to as a "fluorescent sheet with a transparent resin layer".

<Formation of transparent resin layer by transparent resin sheet method>
In the formation of the transparent resin layer by the transparent resin sheet method in this example, the transparent resin sheet is formed by applying a resin solution for producing a transparent resin layer on a PET film using a slit die coater and drying at 130 ° C. for 30 minutes. Got Then, using a vacuum laminator V130 manufactured by Nikko Materials Co., Ltd., the phosphor layer of the phosphor sheet and the transparent resin layer of the transparent resin sheet are heat-bonded at 100 ° C. for 30 seconds in a vacuum atmosphere of 1 hPa. It was pasted together. Then, the PET film on the transparent resin sheet side was peeled off, thereby forming a transparent resin layer on the phosphor layer. As a result, a phosphor sheet with a transparent resin layer was obtained.

<Measurement of film thickness of transparent resin layer>
In the film thickness measurement of the transparent resin layer in this example, the thickness of the phosphor sheet for producing the transparent resin layer at a predetermined position was measured in advance with a micrometer and marked. Then, a transparent resin layer was formed on the phosphor sheet, and then the thickness of the marking portion was measured again with a micrometer. The film thickness of this transparent resin layer was obtained by subtracting the previously measured thickness from the obtained thickness. In this example, the film thickness was measured at 25 points in a grid pattern at 10 mm intervals. From this measurement result, the average value and the film thickness variation (= maximum film thickness-minimum film thickness) of each sample were calculated.

<Porosity measurement>
In the porosity measurement in this example, the phosphor sheet was cut by a focused ion beam (FIB) processing method, and the cross section of the phosphor layer was observed by SEM. Twenty cross sections were observed for one phosphor sheet, and the total cross-sectional area corresponding to the voids of the obtained 20 two-dimensional images was calculated. The porosity of the phosphor layer was obtained by dividing the total cross-sectional area corresponding to the voids by the total cross-sectional area of these 20 two-dimensional images.

<Manufacturing method of illuminant>
In the method for producing a light emitter in this embodiment, the phosphor sheet or the fluorescent sheet with a transparent resin layer (1 cm square) produced as described above is cut by a cutting device (GCUT manufactured by UHT), thereby 1 mm square. 100 pieces of individual sheets were prepared. In this embodiment, the individual sheet is a single piece of a fluorescent material sheet or a fluorescent material sheet with a transparent resin layer. Then, using a die bonding apparatus (manufactured by Toray Engineering), a 1 mm square individual sheet (fluorescent layer or the like) was vacuum-adsorbed with a collet and peeled from the base film. The phosphor layer of this individual sheet was aligned and attached to the surface of the blue LED chip of the LED package in which the flip-chip type blue LED chip was mounted and the reflector was formed around the blue LED chip. .. At this time, an adhesive was applied in advance on the blue LED chip, and the phosphor layer was attached via the adhesive. Silicone resin T15 was used for this adhesive. In this way, a light emitter provided with a phosphor sheet or a phosphor sheet with a transparent resin layer was produced.

<Saturation, total luminous flux measurement>
In the measurement of chromaticity and total luminous flux in this embodiment, 1 W of power is applied to the luminous flux produced as described above to light the LED chip of this luminous flux, and the total luminous flux measurement system (HM-3000, Otsuka). The chromaticity (Cx, Cy) and total luminous flux (lm) of the CIE1931 XYZ color system were measured using (manufactured by Electronics Co., Ltd.). In this embodiment, 10 light emitters (with LED chips) are produced for each phosphor sheet, and the average value of the chromaticity of these 10 light emitters and an index of chromaticity variation are used. The standard deviation (σ) of the chromaticity Cx was obtained.

<Measurement of total luminous flux retention>
In the measurement of the total luminous flux retention rate in this embodiment, 1 W of power is applied to the light emitting body in which each phosphor sheet is mounted on the blue LED chip to light the blue LED chip, and the light emitting body in this lighting state ( The blue LED chip) was left to stand under the conditions of a temperature of 85 ° C. and a humidity of 85%, and the total luminous flux after 300 hours had passed was measured. The durability of the light emitter and its phosphor sheet was evaluated by calculating the total luminous flux retention rate based on the following formula. The higher the total luminous flux retention rate, the better the durability.

Total luminous flux retention rate (%) = (total luminous flux after 300 hours / total luminous flux immediately after the start of the test) × 100

<Color reproduction range measurement>
In the measurement of the color reproduction range in this example, a color filter that transmits red light produced by a known method was placed on the illuminant produced as described above, and the chromaticity of the emitted light was measured. Similarly, the chromaticity of the emitted light was measured for each of the case where the color filter transmitting green light was placed on the illuminant and the case where the color filter transmitting blue light was placed. The DCI ratio was calculated by dividing the area of the triangle having the obtained three chromaticities as the vertices by the area of the DCI chromaticity region. The higher the DCI ratio, the better the color reproducibility.

<Measurement of refractive index>
In the measurement of the refractive index in this embodiment, the refractive index of the refractive index measurement sample is measured by using the refractive index / film thickness measuring device “Prism Coupler MODEL2010 / M” (manufactured by Metricon), whereby the silicone resin is measured. And the refractive index of the cured fluororesin was measured.

<Preparation of refractive index measurement sample>
In the preparation of the refractive index measurement sample in this example, the resin contained in the phosphor sheet is stirred at 1000 rpm for 10 minutes using a planetary stirring defoaming device "Mazelstar KK-400" (manufactured by Kurabo) to defoam. Then, a dispersion liquid of this resin was prepared. This dispersion was dropped on a PET film in an amount of 5 cc and then heated in an oven at 150 ° C. for 1 hour to prepare an average refractive index measurement sample as a refractive index measurement sample.

<Measurement of transmittance>
In the transmittance measurement in this example, the light transmittance of the transparent resin layer containing fine particles has a basic configuration using an integrating sphere attached to a spectrophotometer (U-4100 Spectrophotometer (manufactured by Hitachi, Ltd.)) and has a transmittance. It was obtained by measuring the light transmittance of the measurement sample. As the transmittance measurement sample, the one prepared in each example was used. Regarding the measurement conditions of this light transmittance, the slit was set to 2 nm and the scanning speed was set to 600 nm / min. Further, in the obtained measurement results, the smallest value among the light transmittances at wavelengths of 400 nm to 800 nm was defined as the minimum transmittance.

<Preparation of transmittance measurement sample>
In the preparation of the transmittance measurement sample in this example, the silicone resin and fine particles used for the transparent resin layer are mixed in a polyethylene container having a volume of 300 mL, and a planetary stirring and defoaming device "Mazelstar KK-400" (manufactured by Kurabo). Was stirred at 1000 rpm for 10 minutes and defoamed to prepare a dispersion. This dispersion is applied onto quartz glass with a blade coater and then heated in an oven at 150 ° C. for 1 hour. In this way, the transmittance measurement sample was prepared for each example.

<Measurement of film thickness of transmittance measurement sample>
In the film thickness measurement of the transmittance measurement sample in this example, the thickness of the quartz glass at a predetermined position was measured in advance with a micrometer, and the measured position was marked. Then, after forming a transmittance measurement sample of the transparent resin layer on the quartz glass, the thickness of the marking portion was measured again with a micrometer. The film thickness of this transmittance measurement sample was obtained by subtracting the previously measured thickness of the quartz glass from the obtained thickness. The film thickness was measured at 25 points in a grid pattern at 10 mm intervals, and the average value of these was taken as the film thickness of the transmittance measurement sample.

(Examples 1 to 6) -Effect of particle size of phosphor-
In Examples 1 to 6, a fluorescent material sheet provided with the fluorescent material layer having the composition shown in Table 2 was prepared, and the porosity was measured by the above method. Further, a light emitter (light emitting device) was produced using the phosphor sheets obtained in each of Examples 1 to 6, and the chromaticity, total luminous flux, total luminous flux retention rate, and color reproduction range were measured by the above method. did. The results of these measurements are shown in Table 3. As can be seen with reference to Tables 2 and 3, when the phosphor sheet according to the present invention was used, all of Examples 1 to 6 were able to obtain a light emitting body having excellent color reproducibility and a high luminous flux. .. Further, when the D50 of the red phosphor is 10 μm or more as in the D50 of the red phosphors T2 to T6 shown in Table 1, the total luminous flux is further improved, and the D10 of the red phosphors T3 to T6 shown in Table 1 is further improved. As described above, it was found that when the D10 of the red phosphor is 5 μm or more, the total luminous flux retention rate is further improved. Further, as in D10 and D50 of the red phosphors T1 to T6 shown in Table 1, the larger the D10 and D50 of the red phosphor, the smaller the porosity of the phosphor sheet tended to be.

(Examples 7 to 13) -Effect of phosphor concentration-
In Examples 7 to 13, a fluorescent material sheet provided with the fluorescent material layer having the composition shown in Table 4 was prepared, and the porosity was measured by the above method. Further, a luminescent material was produced using the phosphor sheets obtained in each of Examples 7 to 13, and the chromaticity, total luminous flux, total luminous flux retention rate, and color reproduction range were measured by the above-mentioned methods. The results of these measurements are shown in Table 5. Table 4 reprints the composition of Example 6, and Table 5 reprints the results of Example 6. From Tables 4 and 5, it was found that the higher the concentration of the phosphors such as the red phosphor T6 and the green phosphor, the higher the total luminous flux retention rate.

(Examples 14 to 17) -Effect of silicone fine particles-
In Examples 14 to 17, a fluorescent material sheet provided with the fluorescent material layer having the composition shown in Table 6 was prepared, and the porosity was measured by the above method. Further, a luminescent material was produced using the phosphor sheets obtained in each of Examples 14 to 17, and the chromaticity, total luminous flux, total luminous flux retention rate, and color reproduction range were measured by the above-mentioned methods. The results of these measurements are shown in Table 7. From Tables 6 and 7, it was found that the chromaticity variation (σ (Cx)) was further improved by containing the silicone fine particles.

(Example 18) -A two-layer product consisting of a red phosphor layer and a green phosphor layer-
In Example 18, a phosphor sheet was prepared with a composition in which the silicone resin T15 was 50 wt% and the red phosphor T6 was 50 wt%. Similarly, a phosphor sheet was prepared with a composition in which the silicone resin T15 was 50 wt% and the green phosphor was 50 wt%. The phosphor layer sides of these two obtained phosphor sheets were bonded together using a vacuum laminator V130 (manufactured by Nikko Materials Co., Ltd.), whereby the phosphor layer containing the red phosphor and the green fluorescence were laminated. A phosphor sheet in which a layer containing a body was laminated was prepared, and the void ratio was measured by the above method. Further, a light emitting body was produced using the obtained phosphor sheet, and the chromaticity, the total luminous flux, the total luminous flux retention rate, and the color reproduction range were measured by the above-mentioned method. The results of these measurements are shown in Table 8. From Table 8, it was found that in Example 18, both the improvement in color reproducibility and the high luminous flux can be achieved, but the chromaticity variation becomes large.

(Examples 19 to 25) -Effect of refractive index of resin in phosphor layer-
In Examples 19 to 25, a fluorescent material sheet provided with the fluorescent material layer having the composition shown in Table 9 was prepared. Moreover, the film thickness of the phosphor layer of the phosphor sheet produced in each of Examples 19 to 25 was measured by the above-mentioned method. In addition, the film thickness of the fluorescent material layer was also measured for the fluorescent material sheet of Example 10. Further, a luminescent material was prepared using the phosphor sheets prepared in each of Examples 19 to 25, and the chromaticity, the total luminous flux, and the color reproduction range were measured by the above-mentioned method. The results of these measurements are shown in Table 10. Table 9 reprints the composition of Example 10, and Table 10 reprints the measurement results of Example 10.

As can be seen with reference to Tables 9 and 10, the higher the refractive index of the resin in the phosphor layer, the lower the filling rate of the red phosphor T6 and the green phosphor, the more the illuminant having the same chromaticity can be obtained. It was. Further, when the refractive index of this resin was 1.56, the total luminous flux became the maximum value. It is considered that this is because the difference in refractive index between the resin of the phosphor layer and the air layer becomes large, so that the light extraction efficiency is lowered.

(Examples 26 to 36) -Effect of refractive index of transparent resin layer-
In Examples 26 to 32 and 34 to 36, a resin solution for producing a transparent resin layer was applied onto the phosphor sheet produced in Example 6 using a slit die coater, and the resin solution for producing the transparent resin layer was applied. Was dried at 130 ° C. for 30 minutes to prepare a phosphor sheet having a transparent resin layer on the phosphor layer. In Example 33, a transparent resin sheet is produced by the above method using the silicone resin T15, and the fluorescent material layer and the transparent resin layer are bonded to each other to obtain a fluorescent material sheet having a transparent resin layer on the fluorescent material layer. Made. The film thickness of the transparent resin layer of the fluorescent material sheets prepared in each of Examples 26 to 36 was measured by the above-mentioned method. Further, a light emitting body is produced by attaching the phosphor layer side of the phosphor sheet with a transparent resin layer produced in each of Examples 26 to 36 on the LED chip, and the chromaticity and total luminous flux are measured by the above method. , The total luminous flux retention rate and the color reproduction range were measured. Table 11 shows the types of resins used for producing the resin liquid for producing the transparent resin layer in each of Examples 26 to 36 and the measurement results in Examples 26 to 36.

From Table 11, it was found that the total luminous flux retention rate was improved by providing the transparent resin layer. It was also found that when the refractive index of the resin contained in the transparent resin layer is equal to or less than the refractive index of the resin contained in the phosphor layer, the total luminous flux is improved.

(Examples 37 to 42) -Refractive index of fine particles-
In Examples 37 to 42, a resin liquid for producing a transparent resin layer having the composition shown in Table 12 was prepared. Next, the resin solution for producing the transparent resin layer prepared in each of Examples 37 to 42 is applied onto the phosphor sheet prepared in Example 10, and the resin solution for producing the transparent resin layer is applied at 130 ° C. for 30 minutes. By drying, a fluorescent material sheet having a transparent resin layer on the fluorescent material layer was prepared.

The film thickness of the transparent resin layer of the phosphor sheet produced in each of Examples 37 to 42 was measured by the above-mentioned method. Next, a light emitting body is produced by attaching the phosphor layer side of the fluorescent material sheet with a transparent resin layer produced in each of Examples 37 to 42 on the LED chip, and the chromaticity and totality are adjusted by the above method. The luminous flux, the total luminous flux retention rate, and the color reproduction range were measured. Further, a transmittance measurement sample having a thickness of 100 μm was prepared using the resin liquid for producing the transparent resin layer prepared in each of Examples 37 to 42, and the light transmittance of the transparent resin layer was measured by the above method. .. The difference in refractive index between the resin of the transparent resin layer and the fine particles in each of Examples 37 to 42 and the measurement results thereof are shown in Table 13.

As can be seen with reference to Tables 12 and 13, the smaller the difference between the refractive index of the resin and the refractive index of the fine particles in the transparent resin layer, the higher the minimum transmittance of the transparent resin layer and the higher the total luminous flux. Was done. It was also found that the addition of fine particles to the transparent resin layer suppressed the variation in film thickness of the transparent resin layer. Furthermore, from the results of Examples 37 and 38, it was found that when the silicone resin T15 exhibiting good heat-sealing properties was used, the film thickness variation of the transparent resin layer became particularly large.

(Examples 43 to 47) -Amount of silica fine particles added-
In Examples 43 to 47, a resin liquid for producing a transparent resin layer having the composition shown in Table 14 was prepared. Next, the resin solution for producing the transparent resin layer prepared in each of Examples 43 to 47 is applied onto the phosphor sheet prepared in Example 10, and the resin solution for producing the transparent resin layer is applied at 130 ° C. for 30 minutes. By drying, a fluorescent material sheet having a transparent resin layer on the fluorescent material layer was prepared.

The film thickness of the transparent resin layer of the phosphor sheet produced in each of Examples 43 to 47 was measured by the above-mentioned method. Next, a light emitting body is produced by sticking the phosphor layer side of the fluorescent material sheet with a transparent resin layer produced in each of Examples 43 to 47 on the LED chip, and the chromaticity and totality are adjusted by the above method. The luminous flux, the total luminous flux retention rate, and the color reproduction range were measured. Further, a transmittance measurement sample having a thickness of 100 μm was prepared using the resin liquid for producing the transparent resin layer prepared in each of Examples 43 to 47, and the light transmittance of the transparent resin layer was measured by the above method. .. The difference in refractive index between the resin of the transparent resin layer and the fine particles in each of Examples 43 to 47 and the measurement results thereof are shown in Table 15. Table 14 reprints the compositions of Examples 38 and 39, and Table 15 reprints the results of Examples 38 and 39.

With reference to Tables 14 and 15, it was found that the content of the silica fine particles T31 is preferably 30% by weight or less, more preferably 10% by weight or less, from the viewpoint of the minimum transmittance. Further, from the viewpoint of suppressing the variation in the film thickness of the transparent resin layer, it was found that the content of the silica fine particles T31 is preferably 0.1% by weight or more, and more preferably 1% by weight or more. ..

(Examples 48 to 52) -Amount of alumina fine particles added-
In Examples 48 to 52, a resin liquid for producing a transparent resin layer having the composition shown in Table 16 was prepared. Next, the resin solution for producing the transparent resin layer prepared in each of Examples 48 to 52 is applied onto the phosphor sheet prepared in Example 10, and the resin solution for producing the transparent resin layer is applied at 130 ° C. for 30 minutes. By drying, a fluorescent material sheet having a transparent resin layer on the fluorescent material layer was prepared.

The film thickness of the transparent resin layer of the phosphor sheet produced in each of Examples 48 to 52 was measured by the above-mentioned method. Next, a light-emitting body was produced by attaching the phosphor layer side of the phosphor sheet with a transparent resin layer produced in each of Examples 48 to 52 onto the LED chip, and the chromaticity was adjusted by the above method. The luminous flux, the total luminous flux retention rate, and the color reproduction range were measured. Further, a transmittance measurement sample having a thickness of 100 μm was prepared using the resin liquid for producing the transparent resin layer prepared in each of Examples 48 to 52, and the light transmittance of the transparent resin layer was measured by the above method. .. The difference in refractive index between the resin of the transparent resin layer and the fine particles in each of Examples 48 to 52 and the measurement results thereof are shown in Table 17. Table 16 reprints the compositions of Examples 38 and 41, and Table 17 reprints the results of Examples 38 and 41.

With reference to Tables 16 and 17, it was found that the content of the alumina fine particles is preferably 30% by weight or less, more preferably 10% by weight or less, from the viewpoint of the minimum transmittance. Further, from the viewpoint of suppressing the variation in the film thickness of the transparent resin layer, it was found that the content of the alumina fine particles is preferably 0.1% by weight or more, and more preferably 1% by weight or more.

(Examples 53 to 57) -Amount of silicone fine particles added-
In Examples 53 to 57, a resin liquid for producing a transparent resin layer having the composition shown in Table 18 was prepared. Next, the resin solution for producing the transparent resin layer prepared in each of Examples 53 to 57 is applied onto the phosphor sheet prepared in Example 10, and the resin solution for producing the transparent resin layer is applied at 130 ° C. for 30 minutes. By drying, a fluorescent material sheet having a transparent resin layer on the fluorescent material layer was prepared.

The film thickness of the transparent resin layer of the phosphor sheet produced in each of Examples 53 to 57 was measured by the above-mentioned method. Next, a light-emitting body was produced by attaching the phosphor layer side of the phosphor sheet with a transparent resin layer produced in each of Examples 53 to 57 onto the LED chip, and the chromaticity was adjusted by the above method. The luminous flux, the total luminous flux retention rate, and the color reproduction range were measured. Further, a transmittance measurement sample having a thickness of 100 μm was prepared using the resin liquid for producing the transparent resin layer prepared in each of Examples 53 to 57, and the light transmittance of the transparent resin layer was measured by the above method. .. The difference in refractive index between the resin of the transparent resin layer and the fine particles in each of Examples 53 to 57 and the measurement results thereof are shown in Table 19. Table 18 reprints the compositions of Examples 38 and 40, and Table 19 reprints the results of Examples 38 and 40.

From Tables 18 and 19, it was found that the minimum transmittance can be maintained at 80% or more even when the content of the silicone fine particles is 50% by weight. Further, from the viewpoint of suppressing the variation in the film thickness of the transparent resin layer, it was found that the content of the silicone fine particles is preferably 0.1% by weight or more, and more preferably 1% by weight or more.

(Examples 58 to 62) -particle size of fine particles-
In Examples 58 to 62, a resin solution for producing a transparent resin layer having the composition shown in Table 20 was prepared. Next, the resin solution for producing the transparent resin layer prepared in each of Examples 58 to 62 is applied onto the phosphor sheet prepared in Example 10, and the resin solution for producing the transparent resin layer is applied at 130 ° C. for 30 minutes. By drying, a fluorescent material sheet having a transparent resin layer on the fluorescent material layer was prepared.

The film thickness of the transparent resin layer of the phosphor sheet produced in each of Examples 58 to 62 was measured by the above-mentioned method. Next, a light emitting body is produced by sticking the phosphor layer side of the fluorescent material sheet with a transparent resin layer produced in each of Examples 58 to 62 on the LED chip, and the chromaticity and totality are adjusted by the above method. The luminous flux, the total luminous flux retention rate, and the color reproduction range were measured. Further, a transmittance measurement sample having a thickness of 100 μm was prepared using the resin liquid for producing the transparent resin layer prepared in each of Examples 58 to 62, and the light transmittance of the transparent resin layer was measured by the above method. .. The difference in refractive index between the resin of the transparent resin layer and the fine particles in each of Examples 58 to 62 and the measurement results thereof are shown in Table 21. Table 20 reprints the compositions of Examples 38 and 39, and Table 21 reprints the results of Examples 38 and 39. From Tables 20 and 21, it was found that the smaller the particle size of the fine particles, the higher the minimum transmittance and the variation in the film thickness of the transparent resin layer was suppressed.

(Comparison example)
In the comparative example with respect to Examples 1 to 62, a phosphor sheet was prepared with a composition in which the silicone resin T15 was 40 wt% and the yellow phosphor (YAG-based yellow phosphor) was 60 wt%, and the porosity was increased by the above method. Was measured. Further, a light emitting body was produced using the obtained phosphor sheet, and the chromaticity, the total luminous flux, the total luminous flux retention rate, and the color reproduction range were measured by the above-mentioned methods. The results of these measurements are shown in Table 22. From Table 22, it was found that when a YAG-based yellow phosphor was used, the color reproduction range was 70%, which was unsuitable as a backlight for a liquid crystal display.

As described above, the phosphor sheet according to the present invention, the light emitting body using the same, the light source unit, the display, and the method for manufacturing the light emitting body are the phosphor sheet that achieves both improvement in color reproducibility and high luminous flux. It is suitable for manufacturing a light emitter, a light source unit, a display, and a light emitting body using the above.

1 Fluorescent material 2 Fluorescent material layer 3 Support 4 Fluorescent material sheet 5 Transparent resin layer 6 Cutlery 7 Single-sided fluorescent material layer 8 Collet 9 LED chip 10 Reflector 11 Substrate 12 Transparent encapsulant 13 Luminescent body 14 Resin

Claims (18)

A phosphor layer containing a red phosphor, a β-type sialone phosphor, and a resin ,
A transparent resin layer laminated on the phosphor layer and containing fine particles,
With
The red phosphor is a Mn-activated compound fluoride represented by the general formula (1).
The phosphor layer is composed of a single layer or a plurality of layers containing the red phosphor, the β-type sialone phosphor, and the resin.
The red fluorescent substance, the β-type sialon fluorescent substance, and the resin are contained in the same layer.
The (D90-D10) / D50 of the red phosphor is 0.5 or more and 1.5 or less.
The sum of the percentage proportions and the β-sialon phosphor of the red phosphor in the total solid content in the phosphor layer, 57 wt% or more state, and are 90 wt% or less,
A phosphor sheet characterized in that the average particle size of the fine particles contained in the transparent resin layer is 1 nm or more and 100 nm or less.
(General formula)
A ₂ MF ₆ : Mn ・ ・ ・ (1)
(In the general formula (1), A is one or more alkali metals selected from the group consisting of Li, Na, K, Rb and Cs and containing at least one of Na and K, and M is Si. , Ti, Zr, Hf, Ge and Sn.) One or more tetravalent elements selected from the group. The phosphor sheet according to claim 1, wherein the resin has a refractive index of 1.45 or more and 1.7 or less. The fluorescent material sheet according to claim 1 or 2, wherein the resin is a silicone resin. The fluorescent substance according to any one of claims 1 to 3, wherein the ratio of the red phosphor to the total solid content in the phosphor layer is 20% by weight or more and 60% by weight or less. Sheet. The phosphor sheet according to any one of claims 1 to 4, wherein the D50 of the red phosphor is 10 μm or more and 40 μm or less. The phosphor sheet according to any one of claims 1 to 5, wherein the D10 of the red phosphor is 3 μm or more. The phosphor sheet according to any one of claims 1 to 6, wherein the porosity in the phosphor layer is 0.1% or more and 3% or less. The fluorescent sheet according to any one of claims 1 to 7, wherein the fluorescent layer contains fine particles. The phosphor sheet according to claim 8, wherein the fine particles are silicone fine particles. The phosphor sheet according to any one of claims 1 to 9, wherein the refractive index of the resin contained in the transparent resin layer is 1.3 or more and 1.6 or less. The phosphor sheet according to claim 10 , wherein the refractive index of the resin contained in the transparent resin layer is equal to or less than the refractive index of the resin contained in the phosphor layer. The phosphor sheet according to any one of claims 1 to 11, wherein the fine particles contained in the transparent resin layer are one or more selected from silica fine particles, alumina fine particles, and silicone fine particles. .. The phosphor sheet according to any one of claims 1 to 12 , wherein the transparent resin layer has a minimum transmittance of 80% or more at a wavelength of 400 nm to 800 nm. The phosphor according to any one of claims 1 to 13 , wherein the ratio of the fine particles to the total solid content in the transparent resin layer is 0.1% by weight or more and 30% by weight or less. Sheet. The step of individualizing the fluorescent material sheet according to any one of claims 1 to 14 and the individualizing step.
A pickup process for picking up the individualized fluorescent material sheet and
The sticking process of sticking the individualized phosphor sheet to the light source, and
A method for producing a luminescent material, which comprises. A light emitting body comprising the phosphor sheet according to any one of claims 1 to 14. A light source unit comprising the phosphor sheet according to any one of claims 1 to 14. A display comprising the light source unit according to claim 17.

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