JP2006348088A - Fluorescent material composition and use thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fluorescent material for white light emitting element to use blue to ultraviolet rays as a light source. <P>SOLUTION: The composition contains one or more substances selected from nitride fluorescent material and oxynitride fluorescent material and a fluorine-containing resin. Preferably, the fluorine-containing resin is an alloy containing one or more resins selected from ETFE, PTFE, FEP, PFA, PVDF, PVF and PCTFE. The invention further relates to a fluorescent sheet composed of the composition and a white light emitting element produced by combining the composition with a blue light emitting element. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

The present invention relates to a phosphor composition that can be used for a light source including a short wavelength light emitting element such as a blue light emitting diode (blue LED), an ultraviolet light emitting diode (ultraviolet LED), or a laser diode (LD) that emits blue light or ultraviolet light. , A sheet using the same, and a light-emitting element.

In recent years, white LEDs have been widely used, and in particular, white LEDs combining blue LEDs and yellow phosphors are used as light sources for mobile phone liquid crystal displays, auxiliary lights for cameras, and the like. A typical white LED has a structure in which a blue LED is sealed with a mixture of phosphor powder and resin (see Patent Document 1).
Japanese National Patent Publication No. 11-500584

In the white LED, a part of the blue light emitted from the blue LED hits the phosphor and is absorbed, emits yellow fluorescence, and emits white light by a mixed color of blue and yellow having a complementary color relationship. However, this white light does not contain much red component and also lacks green color, so it has poor color reproducibility and does not look like a beautiful red color even if it is illuminated as an illumination light on a red object. Has the disadvantages. Therefore, this white light is sometimes called pseudo white.

On the other hand, a combination of a blue LED and a green phosphor, a red phosphor, a combination of an ultraviolet LED and three primary color phosphors of blue, green and red light, and further mixing a yellow phosphor with three colors, Trial manufacture of white LED which mixed four colors and improved color reproducibility is also performed. However, there are various problems and industrially produced products are mostly pseudo white LEDs that are a combination of blue LEDs and yellow phosphors.

If white LEDs with improved color reproducibility can be used for lighting, it is said that fluorescent lamps inevitably use mercury that is unavoidably used, and it is long-life and energy-saving, so it is said to be environmentally friendly. However, at this stage, it cannot be said that it contributes to energy saving because the luminous efficiency does not reach that of fluorescent lamps. If LEDs with the current output are arranged, a large number of LEDs are used. There is a problem that it cannot be beaten. Solving these problems is an important industrial issue.

In order to improve the luminous efficiency, it is most important to increase the luminous efficiency of blue and ultraviolet LEDs, but besides this, a sufficiently efficient phosphor suitable for this application has not been obtained, It is also an important issue that the sealing resin is deteriorated by ultraviolet rays and the life of the light source is shortened, that the amount of light per LED chip is small.

As for phosphors, recently discovered nitride phosphors and oxynitride phosphors are well excited by blue light and ultraviolet light, and are suitable for light sources combining blue to ultraviolet light emitting elements and phosphors. (Patent Documents 2 to 6, Non-Patent Document 1).
JP 2002-363554 A JP 2003-336059 A JP 2003-124527 A JP 2003-206481 A JP 2004-186278 A J. et al. W. H. van Krebel, "On new rare-earth doped M-Si-Al-O-N materials", TU Eindhoven, The Netherlands, p. 145-161 (1998)

Further, it has been found that CaSiAlN ₃ and Ca ₂ (Si, Al) ₅ N ₈ activated with rare earth elements also have similar fluorescent characteristics (see Patent Document 7 and Non-Patent Documents 2 to 3).
JP 2004-244560 A Proceedings of the 52nd Joint Conference on Applied Physics (March 2005, Saitama University) p. 1614-1615 Proceedings of the 65th JSAP Academic Lecture Meeting (September 2004, Tohoku Gakuin University) p. 1282-1284

In addition, nitride and oxynitride phosphors such as aluminum nitride, magnesium magnesium nitride, calcium calcium nitride, barium silicon nitride, gallium nitride, and silicon zinc nitride (hereinafter referred to as nitride phosphor and oxynitride fluorescence in order) (Also called the body) is being studied.

In addition, an epoxy resin has been widely used as a sealing resin (see Patent Document 1). However, the epoxy resin has a drawback that the resin is colored when exposed to ultraviolet rays for a long time, and the light transmittance is lowered to shorten the life of the light source. To solve this disadvantage, recently, a silicone resin has been used as a sealing resin. (Patent Document 8).
JP 2005-136379 A

However, it has been found that silicon resin also deteriorates when exposed to a large amount of ultraviolet rays. Recently, development of high-power LEDs has been promoted, and the power consumption and light energy density per chip have increased. Because of this tendency, resin degradation due to heat and ultraviolet rays tends to be significant.

Since white LEDs obtained up to now have a luminous efficiency that does not reach that of fluorescent lamps, there is a strong demand for white LEDs that have higher luminous efficiency than fluorescent lamps. White LEDs using oxynitride phosphors and nitride phosphors such as sialon phosphors are more efficient than incandescent lamps. Therefore, high output, high luminous efficiency and improvement of lighting characteristics must be achieved.

On the other hand, in the case of an oxynitride phosphor or a nitride phosphor, the excitation spectrum of the phosphor has a skirt extending to about 250 nm on the shortest wavelength side, and in order to absorb the excitation light to the maximum, to about 250 nm. Although it is desirable to use a highly light-transmitting resin, many resins have low light transmittance on the short wavelength side.

In view of the state of the prior art, the present inventors have studied for the purpose of providing a long-life light source excellent in luminous efficiency, in particular, a white light source. As a result, the oxynitride phosphor and nitride phosphor and fluorine-containing The knowledge that the object can be achieved by using a resin in combination is obtained, and the present invention has been achieved.

As described above, in a white light source using a blue, purple light emitting element, or ultraviolet light emitting element, the resin used is exposed to the blue to ultraviolet light emitted by the light emitting element, so that the resin deteriorates and has sufficient durability. There was a problem that the light source had not been obtained. In particular, studies on high-power light-emitting elements that take out more light by increasing the amount of current injected per piece have been underway recently, and the unit area is exposed to stronger light. Further, since the amount of heat generated per element increases, the element temperature rises, and deterioration due to both heat and light progresses.

Further, due to the increase in power consumption accompanying the increase in output, further improvement in light emission efficiency is required, and countermeasures are also required for the structure and constituent materials of the light emitting element. For example, when light passes through the interface between two media, the greater the difference in refractive index between the media, the greater the reflectivity, and thus the lower the light transmittance. Therefore, the design of the refractive index of the material constituting the light path of the light emitting element affects the light extraction efficiency from the light emitting element, and thus the light emission efficiency.

Furthermore, some light-emitting elements include phosphors that emit visible light when excited by blue or ultraviolet light. Therefore, the light that should be transmitted by the resin used is not only visible light but also light with a shorter wavelength. Must be transparent. Even if the light transmittance on the short wavelength side is a resin having a high visible light transmittance, it is not always high, and it is necessary to study the light transmittance.

In addition, the resin is often mixed with a phosphor and used as a sealing resin, but the sealing resin must transmit light, and impurities such as bubbles that scatter light must be eliminated as much as possible. . In particular, air bubbles must be minimized. For this purpose, it is necessary to improve the familiarity between the phosphor and the resin interface, and it is also necessary that the dispersion state of the phosphor in the resin is maintained in an appropriate state.

The object of the present invention is to solve the above-mentioned problems of the prior art and to provide a light emitting device excellent in luminous efficiency, for example, a white LED, particularly a white LED using a blue LED or an ultraviolet LED as a light source, and is suitable for use therein. It is to provide a resin composition and, more specifically, a sealing resin or sheet as a specific embodiment stably on an industrial scale.

The present inventor has conducted various experimental studies on resin-encapsulated white light sources using nitride phosphors and oxynitride phosphors. The phosphor emission characteristics, resin composition, light transmittance, and UV resistance The inventors have obtained the knowledge that characteristics such as the luminous efficiency and lifetime of a white light source are greatly influenced by appropriately combining various factors such as the dispersion state of the phosphor and the resin.

That is, the present invention is a composition comprising at least one selected from the group consisting of a nitride phosphor and an oxynitride phosphor and a resin containing fluorine. Preferably, it is selected that the resin containing fluorine is an alloy containing at least one resin selected from the group consisting of ETFE, PTFE, FEP, PFA, PVDF, PVF, and PCTFE.

Moreover, this invention is a sealing material characterized by consisting of the said composition, and is a fluorescent substance sheet. In addition, the phosphor composite sheet is characterized in that the phosphor sheet is used as a part of the constituent parts.

Furthermore, the present invention is a light emitting device comprising the above composition, a sealant, a phosphor sheet, or a phosphor composite sheet, and a blue to ultraviolet light emitting device.

The composition of the present invention has a feature that the oxynitride phosphor and the nitride phosphor have a small temperature change in emission intensity and a long life, and a fluorine-containing high transmittance of excitation light of the phosphor. Since it contains a resin, it is excellent in luminous efficiency, and is suitable for providing, for example, a white LED, particularly a white LED using a blue LED or an ultraviolet LED as a light source.

Reflecting the characteristics of the composition, the sealing material, the phosphor sheet, the phosphor composite sheet of the present invention, and the light emitting element containing these and the blue light emitting element or the ultraviolet light emitting element are excellent in emission characteristics and long. It is a lifetime.

As the phosphor used in the present invention, a nitride phosphor or an oxynitride phosphor is selected.

Among phosphors that emit visible light when excited by blue, purple, or ultraviolet light, nitride and oxynitride phosphors are superior in luminous efficiency, lifetime, and temperature characteristics compared to other phosphors. Has characteristics. For example, many phosphors have been proposed in recent years, such as α sialon and β sialon as mother crystals, doped with rare earth elements Eu and Yb, CaSiAlN ₃ , Ca ₂ (Si, Al) ₅ N ₈ . ing. The characteristics of these nitride and oxynitride phosphors are that the temperature change of the emission intensity is small, the stability of the crystal is long, and the life is long compared to oxide phosphors and sulfide phosphors.

Of the nitride phosphor and oxynitride phosphor, the α sialon phosphor will be described in detail. General formula: (M1) _X (M2) _Y (Si) _{12− (m + n)} (Al) _{m + n} (O) _n ( N) _16-n (where M1 is one or more elements selected from the group consisting of Li, Mg, Ca, Y and lanthanide metals (excluding La and Ce), and M2 is Ce, Pr, Eu, Tb. One or more elements selected from Yb, Er, 0.3 ≦ X + Y ≦ 1.5, 0 <Y ≦ 0.7, 0.6 ≦ m ≦ 3.0, 0 ≦ n ≦ 1.5, X + Y = m / 2), which is a phosphor composed of an α sialon type compound (hereinafter simply referred to as α type sialon). Preferably, the amount of oxygen contained in the α-sialon powder is preferably 0.4 mass% or less than the value calculated based on the general formula, M1 is Ca, and M2 is Eu. A phosphor is preferred.

The α sialon phosphor may be a calcium compound that does not contain oxygen in at least a portion of the calcium material. In addition, after the phosphor is manufactured, it is preferable that the phosphor is further acid-treated, since the emission intensity may increase.

When the present inventors measured the fluorescence characteristics of the α-sialon phosphor using a fluorescence spectrophotometer manufactured by Hitachi, the excitation spectrum had peaks at 300 nm and 400 nm, and an emission spectrum measured at a wavelength of 400 nm. The peak wavelength of 580 nm is 580 nm.

For nitride phosphors and oxynitride phosphors, if a coating film of a material having a refractive index between the phosphor and the resin is attached to the surface, both the nitride phosphor and the oxynitride phosphor The luminous efficiency is increased, which is preferable. In this case, the thickness (10 to 180) / n (unit: nanometer) (where n is the refractive index of the transparent film, 1.2 to 2.5), preferably at least partially on the surface of the phosphor particles. Is preferably a phosphor with a surface coat whose transparent film has a refractive index of 1.5 to 2.0.

These nitride phosphors and oxynitride phosphors can fully exhibit their characteristics only when used together with a resin that is resistant to ultraviolet rays and has a long lifetime.

Therefore, in the present invention, the resin used is a resin containing fluorine, and examples thereof include ETFE, PTFE, FEP, PFA, PVDF, PVF, and PCTFE.

As described above, in order to increase the luminous efficiency of the nitride phosphor or the oxynitride phosphor, the visible light transmittance of the resin used in the present invention is high, and the transmittance of the excitation light of the phosphor used is also high. It is preferable. A resin containing fluorine is selected as the resin having such characteristics. However, a fluorine-containing resin typified by a fluororesin has a small surface energy and is generally difficult to mix with other materials. However, according to the study of the present inventor, a nitride phosphor or an oxynitride fluorescence It was found that the body can be easily mixed with a resin melted in a heat-melted resin or a solvent by a kneader such as a stirring tank with a stirring blade or a three-roller. Furthermore, effects such as shortening of the mixing time and vacuum defoaming time can be obtained by treating the phosphor powder with a silane coupling agent and surface coating with silica or alumina.

The composition of the present invention was able to achieve mixing of a fluorine-containing resin, which is generally considered difficult to mix with other materials, with a phosphor having a specific composition such as a nitride phosphor or an oxynitride phosphor. Therefore, the light source combined with blue, violet and ultraviolet light emitting elements has a characteristic that it can exhibit the characteristics of long life and high efficiency. In particular, in a light source combined with a light emitting element of purple or ultraviolet light, the difference is significant from the case where a conventional epoxy resin or silicon resin is used.

For example, in the case of an α sialon phosphor, the excitation spectrum of a nitride phosphor or an oxynitride phosphor has two peaks near 400 nm and near 300 nm, and the short wavelength side has a small absorption at about 250 nm. Similarly, the phosphor also has a small absorption near 250 nm. Therefore, when the thickness of the fluorine-containing resin is 50 μm, the light transmittance at 250 nm is preferably 60% or more.

The light transmittance of the resin is the crystallinity, symmetry of the polymer structure that affects the crystallinity, regularity of the three-dimensional structure, use of a nucleating agent, addition of a compatibilizing agent, density distribution, refractive index, refractive index distribution, etc. Depends on. Of the fluorine-containing resins, fluororesin, especially PTFE, is a crystalline polymer and has low transparency. However, the transparency can be improved by devising the form of the monomer, copolymerization, processing method, and the like. For example, FEP, ETFE, and PFA improve the processability of PTFE, which is a typical fluororesin homopolymer, by copolymerization, and at the same time, improve the translucency. In addition, perfluorodioxole polymer (DuPont, trade name: Teflon RF) and perfluorobutenyl vinyl ether polymer (Asahi Glass Co., trade name: Cytop) have an amorphous structure because they have a cyclic structure in the main chain. And is highly transparent.

FEP, ETFE, PFA, Teflon FR (registered trademark), and Cytop (registered trademark) were each processed into a film with a thickness of 50 μm, and the light transmission spectrum was measured with an ultraviolet-visible light spectrophotometer. A transmittance of about 60 to 90% was exhibited. The transparency of the film can be improved by increasing the cooling rate and reducing the surface roughness of the roll surface during film production.

Preferably, the fluorine-containing resin is an alloy containing at least one resin selected from the group consisting of ETFE, PTFE, FEP, PFA, PVDF, PVF, and PCTFE. By alloying, it becomes easy to become amorphous and the transparency can be improved. In particular, an alloy of PVDF and PMMA is suitable for the purpose of the present invention because it is made of a relatively inexpensive material and is excellent in transparency and workability. The alloy of 80 parts by mass of PVDF and 20 parts by mass of PMMA is particularly excellent in transparency, and the light transmittance at a wavelength of 250 nm of the film (trade name: DX film, manufactured by Denki Kagaku Kogyo Co., Ltd.) is 80 as measured above. Since it shows ˜90% or more, it is particularly suitable for the purpose of the present invention.

These fluorine-containing resins have the highest weather resistance among the resins, and are known as resins having the least deterioration under an environment exposed to sunlight outdoors. Therefore, it is the most excellent resin as a resin used for a white light source having a blue or violet light source or an ultraviolet light source, and the life of the white light source can be greatly extended compared to the conventional one.

Furthermore, most of the fluorine-containing resins belong to the smallest group with a refractive index of 1.4 or less among many resins, and since the difference from the refractive index of gas is small, the efficiency of taking out light into the gas is high. There is a feature. In addition, there is an advantage that the Abbe number is large and the chromatic aberration is small.

The composition of the present invention is suitably used as a sealing material in the following exemplified applications. That is, in the case of a surface-mounted LED, an ink for screen printing mainly composed of the composition of the present invention is prepared by diluting with a solvent, screen-printed, dried, and vacuum-heated to form the LED element of the present invention. It can be embedded with a composition. In the case of a bullet-type LED, an LED element is fixed to a lead frame and wire-bonded, and then the composition of the present invention heated and melted is potted thereon and heated and cured in a vacuum to form the LED element. Can be covered. In some cases, the LED element may be filled with another resin layer, and a layer of the composition of the present invention may be formed thereon. At this time, it is preferable to use a resin having a high refractive index as the resin for filling the LED element because the light extraction efficiency is increased.

Moreover, it is preferable to process the composition of the present invention into a sheet and use it as a phosphor sheet. The advantage in this case is that, in the case of the above-mentioned method by potting or screen printing, since the resin undergoes a process of softening or melting, there is a possibility that the phosphor moves in the resin and the distribution becomes non-uniform. There is a drawback that the color tone and color distribution of the light source may change. When the sheet of the present invention is used, the phosphor does not change its position in the assembly process, and if the phosphor is evenly dispersed in the sheet, the phosphor will be unevenly distributed later to emit light. It is possible to prevent color deviation and color change.

The above-mentioned sheet in which the phosphor powder is dispersed can be produced by a melt T-die extrusion method or by applying a mixture of a phosphor and a resin to the surface of a previously prepared sheet.

Furthermore, the phosphor sheet may be formed into a plurality of layers, or the phosphor sheet surface may be covered with another sheet to form a plurality of layers, or a phosphor composite sheet.

The light emitting device of the present invention includes a blue light emitting device or an ultraviolet light emitting device, a nitride phosphor or an oxynitride phosphor having a characteristic of emitting light at, for example, 580 nm, and the nitride phosphor or oxynitride phosphor. Since it contains a fluorine-containing resin that easily transmits the excitation light, it is a light-emitting element having excellent light emission characteristics and a long lifetime.

Example 1
The α sialon phosphor was synthesized as follows. As the composition of the raw material powder, 83.0 parts by mass of silicon nitride powder (manufactured by Denki Kagaku Kogyo Co., Ltd., 9 FW grade) and 10.5 parts by mass of aluminum nitride powder (F grade made by Tokuyama Co., Ltd.) Europium oxide powder (manufactured by Shin-Etsu Chemical Co., Ltd., RU grade) was 1.5 parts by mass, and calcium sulfide powder (manufactured by Wako Pure Chemical Industries, Ltd.) was 5.5 parts by mass.

Next, the raw material powder was wet ball mill mixed with a silicon nitride pot and balls in an ethanol solvent for 3 hours, filtered and dried to obtain a mixed powder. It was 1.2 mass% when the oxygen content of mixed powder was measured with the oxygen analyzer by LECO. 100 g of the mixed powder was filled in a boron nitride crucible having an inner diameter of 100 mm and a height of 60 mm, and was subjected to heat treatment at 1750 ° C. for 12 hours in a nitrogen atmosphere at atmospheric pressure using an electric furnace of a carbon heater. The obtained product was crushed in an agate mortar and passed through a sieve having an opening of 45 μm. By these operations, a synthetic powder which is a phosphor of α-sialon was obtained.

The composition of the α-type sialon powder obtained by calculation from the metal component analysis value of the obtained powder is Ca _0.48 Eu _0.05 Si _10.4 Al _1.6 O _0.5 N _15.5. X + Y = 0.53, Y / (X + Y) = 0.09. The amount of oxygen calculated from the composition was 1.36% by mass. It was 1.40 mass% when the oxygen amount of the obtained sialon fluorescent substance was measured with the oxygen analyzer made from LECO. Moreover, when the fluorescence characteristic was measured using a fluorescence spectrophotometer manufactured by Hitachi, the peak wavelength of the emission spectrum measured at an excitation wavelength of 400 nm was 580 nm.

30 g of the obtained α sialon phosphor was added to 100 g of water together with 0.3 g of an epoxy silane coupling agent (KBE402, manufactured by Shin-Etsu Silicone Co., Ltd.), left overnight with stirring, filtered and dried, An α sialon phosphor treated with a ring agent was obtained. 1 part by mass of the obtained silane coupling agent-treated α-sialon phosphor powder and 100 parts by mass of CYTOP (CTX-809A, fluorine-based solvent solution of perfluorobutenyl vinyl ether polymer) manufactured by Asahi Glass Co., Ltd. The beaker was well stirred and mixed to obtain a phosphor and resin composition.

The composition was dropped on an LED having an emission peak wavelength of 450 nm mounted on a surface mount package, and heated at 180 ° C. for 1 hour in a vacuum dryer. As a result, a white light-emitting element including an LED emitting blue light of 450 nm, an oxynitride phosphor that absorbs blue light and emits yellow light, and a fluororesin was formed. This element was put into a thermostat of 85 ° C., and a current of 20 mA was continuously supplied, and the total amount of light at the beginning and after one year was measured. If the initial value is 100, it was 95 after one year.

(Comparative Example 1) 0.5 parts by mass of the silane coupling agent-treated α-sialon phosphor synthesized in Example 1 and 5.0 parts by mass of an epoxy resin (NLD-SL-2101 manufactured by Sanyu Rec) were kneaded, and the emission wavelength was 450 nm. A blue LED was potted, vacuum degassed, and heat-cured at 110 ° C. to produce a surface-mounted LED. This surface-mounted LED was placed in a constant temperature bath at 85 ° C., and a current of 20 mA was kept flowing, and the total amount of light at the initial stage and after one year was measured. Assuming that the initial value of Example 1 is 100, the initial value of Comparative Example 1 was 96 and 62 after one year.

(Example 2) The composition of Example 1 was placed in a flat quartz container at the bottom and heated to volatilize the solvent to prepare a sheet in which a phosphor having a thickness of 100 µm was dispersed. This sheet was placed in an eye super UV tester for durability test and allowed to stand for 300 hours. In order to evaluate the fluorescence characteristics of the sheet, the peak intensity of fluorescence emitted by applying excitation light of 300 nm using a fluorescence spectrophotometer manufactured by Hitachi, Ltd. was compared. Met.

(Comparative Example 2) 20 parts by mass of α-sialon phosphor powder synthesized in Example 1, 100 parts by mass of hydrogenated bisphenol A type epoxy resin (XY8000, manufactured by Japan Epoxy Resin Co., Ltd.), 80 parts by mass of acid anhydride (MeHHP) Then, 1 part by mass of a curing accelerator was mixed with a self-revolving stirrer, defoamed, and then sandwiched between glass plates to be cured to prepare a sheet having a thickness of 100 μm. This sheet was subjected to a durability test and fluorescence measurement in the same manner as in Example 2. The initial value of the durability test was 51, and 22 after the durability test (assuming the initial value of Example 2 was 100).

(Example 3)
As composition of the raw material powder, 33.5 parts by mass of silicon nitride powder (manufactured by Denki Kagaku Kogyo Co., Ltd., 9 FW grade) and 29.5 parts by mass of aluminum nitride powder (F grade made by Tokuyama Co., Ltd.) Europium oxide powder (manufactured by Shin-Etsu Chemical Co., Ltd., RU grade) was 2.5 parts by mass, and calcium nitride (manufactured by Wako Pure Chemical Industries, Ltd.) was 35.0 parts by mass.

Next, the raw material powder was subjected to wet ball mill mixing with a silicon nitride pot and balls in a xylene solvent for 3 hours, filtered and dried to obtain a mixed powder. 100 g of the mixed powder was filled in a boron nitride crucible having an inner diameter of 100 mm and a height of 60 mm, and heat treatment was performed at 1800 ° C. for 12 hours in a nitrogen atmosphere at a pressure of 0.9 MPa in a carbon heater electric furnace. The obtained product was crushed in an agate mortar and passed through a sieve having an opening of 45 μm to obtain a CaAlSiN ₃ : Eu phosphor powder.

With respect to the phosphor powder, the peak wavelength of the emission spectrum measured at an excitation wavelength of 400 nm is 650 nm.

The obtained CaAlSiN ₃ : Eu phosphor powder (5.0 g) was well dispersed in 50 ml of isopropanol in which 0.5 g of magnesium ethoxide (chemical formula: Mg (OC ₂ H ₅ ) ₂ ) was dissolved. While stirring the dispersion well, 50 ml of a 15% aqueous ammonia solution was added dropwise. The obtained slurry was filtered, washed and dried, and fired at 1100 ° C. in a nitrogen atmosphere for 1 hour to obtain a phosphor with a magnesia film.

As a result of observing the obtained phosphor with a transmission electron microscope, the thickness of the magnesia film was approximately 60 nm. As a result of measuring the fluorescence spectrum, the emission spectrum intensity was 115.

10 parts by mass of this phosphor powder, 72 parts by mass of commercially available PVDF (manufactured by Arkema Co., Ltd., trade name: Kyner PVDF, 1000HD), and commercially available PMMA (manufactured by Mitsubishi Rayon Co., Ltd., trade name: Acripet, MF001) 8 parts by mass were heated, melted, and mixed, and a sheet having a thickness of 200 μm was prepared by an extrusion molding machine with a T-die. This sheet was subjected to a durability test using an eye super UV tester in the same manner as in Example 2. The emission intensity at the peak wavelength of the emission spectrum measured at an excitation wavelength of 400 nm was 95 after the durability test, assuming that 100 before the durability test.

(Example 4) 90.1 parts by mass of silicon nitride powder (manufactured by Denki Kagaku Kogyo Co., Ltd., 9FW grade), 9.0 parts by mass of aluminum nitride powder (manufactured by Tokuyama Co., Ltd., F grade), europium oxide powder (Shin-Etsu) 0.9 part by mass of Chemical Industry Co., Ltd., RU grade) was mixed in an ethanol solvent for 2 hours using a silicon nitride pot and ball, filtered and dried to obtain a mixed powder. A boron nitride crucible with an inner diameter of 100 mm and a height of 60 mm is filled with 100 g of the mixed powder, and a heat treatment is performed at 1900 ° C. for 12 hours in a nitrogen atmosphere of 0.9 MPa in an electric furnace of a carbon heater. The mixture was crushed in an agate mortar and passed through a sieve having an opening of 45 μm. By these operations, a synthetic powder which is a phosphor of β-sialon was obtained. When the fluorescence characteristics were measured using a fluorescence spectrophotometer manufactured by Hitachi, the peak wavelength of the emission spectrum measured at an excitation wavelength of 400 nm was 540 nm.

10 g of the obtained phosphor was added to 50 g of water together with 0.1 g of an epoxy-based silane coupling agent (KBE402, manufactured by Shin-Etsu Silicone Co., Ltd.), left overnight with stirring, filtered and dried, and a silane coupling agent. A treated oxynitride phosphor was obtained. 1 part by mass of the obtained silane coupling agent-treated β sialon phosphor powder and 100 parts by mass of Cytop (CTX-809A, fluorine-based solvent solution of perfluorobutenyl vinyl ether polymer) manufactured by Asahi Glass Co., Ltd. The mixture of the phosphor and the resin was obtained by stirring and mixing well. This composition was placed in a flat quartz container at the bottom and heated to volatilize the solvent to prepare a sheet in which a phosphor having a thickness of 100 μm was dispersed.

This sheet was placed in an eye super UV tester for durability test and allowed to stand for 300 hours. When the fluorescence intensity of the sheet was compared with the peak intensity of fluorescence emitted by applying excitation light of 400 nm using a fluorescence spectrophotometer manufactured by Hitachi, assuming that the initial durability test was 100, it was 94 after the durability test. .

(Comparative Example 3) 20 parts by mass of β sialon phosphor powder synthesized in Example 4, 100 parts by mass of hydrogenated bisphenol A type epoxy resin (XY8000, manufactured by Japan Epoxy Resins Co., Ltd.), 80 acid anhydride (MeHHP) Mass parts and 1 part by mass of a curing accelerator were mixed with a self-revolving stirrer, defoamed, and then sandwiched between glass plates to be cured, thereby forming a sheet having a thickness of 200 μm. This sheet was subjected to a durability test and fluorescence measurement in the same manner as in Example 4. The initial durability test was 92, and 51 after the durability test.

Since the composition of the present invention has high luminous efficiency and remarkably superior durability compared to conventional products, a light emitting element with high luminous efficiency, particularly a white light emitting element combining a light emitting element emitting blue to ultraviolet light and a phosphor. Is extremely useful in industry. In particular, since the lifetime of white light-emitting LEDs that use ultraviolet light-emitting LEDs as an excitation light source and the light emission efficiency are improved, there is a possibility of being used as next-generation lighting that replaces the current mainstream fluorescent lamps as mercury-free lighting, It is very useful from the viewpoint of industrial and global environmental conservation.

The sealing material, the fluorescent sheet, and the fluorescent composite sheet, which are embodiments of the composition of the present invention, can be suitably used for each application when the composition is put to practical use, and increase the work efficiency in the assembly of the light emitting device. Since an effect can be exhibited, it is industrially useful.

Since the light-emitting device of the present invention contains the composition and a device that emits blue to ultraviolet light, it may be used as mercury-free lighting, as next-generation lighting that replaces the current mainstream fluorescent lamps. Yes, it is very useful from the viewpoint of industrial and global environmental conservation.

Claims (9)

A composition comprising at least one selected from the group consisting of a nitride phosphor and an oxynitride phosphor and a resin containing fluorine. 2. The composition according to claim 1, wherein the fluorine-containing resin is an alloy containing one or more resins selected from the group consisting of ETFE, PTFE, FEP, PFA, PVDF, PVF, and PCTFE. A sealing material comprising the composition according to claim 1. A phosphor sheet comprising the composition according to claim 1. A phosphor composite sheet, wherein the phosphor sheet according to claim 4 is used as a part of a constituent part. A light emitting device comprising the composition according to claim 1 or 2 and a blue to ultraviolet light emitting device. A light emitting device comprising the sealing material according to claim 3 and a blue to ultraviolet light emitting device. A phosphor sheet comprising the phosphor sheet according to claim 4 and a blue to ultraviolet light emitting element. 6. A light emitting device comprising the phosphor composite sheet according to claim 5 and a blue to ultraviolet light emitting device.