JP5884717B2 - Cured silicone resin containing sulfide phosphor particles with coating film and method for producing the same - Google Patents

Description

  The present invention relates to a cured product of a silicone resin containing coated phosphor sulfide particles, which has excellent light-emitting properties, has extremely high water resistance and moisture resistance, and is suitable as a light-emitting diode (LED) device, and production thereof Regarding the method.

Oxide phosphors and sulfide phosphors well known as light-emitting materials are composed of a compound phase represented by a composition formula of Sr ₃ SiO ₅ : Eu, SrS: Eu, SrGa ₂ S ₄ : Eu. There is. Among them, sulfide phosphors such as SrS: Eu and SrGa ₂ S ₄ : Eu are used for phosphors for high color rendering white LEDs, and emit red light by absorbing blue excitation light from the blue LEDs and the blue light. White light with high color rendering can be obtained by mixing light and green light.

  However, these sulfide phosphors have low water resistance and moisture resistance, and are deteriorated by the formation of hydrates, sulfates or carbonates on the surface by water vapor or water in the air, resulting in a decrease in luminance and a change in color tone. There is a problem that it is easy to wake up. Further, when it is deteriorated by water vapor or water in the air, there is a problem that a toxic and corrosive gas such as hydrogen sulfide is generated due to a reaction between the sulfide phosphor and moisture.

  In particular, in an LED light emitting device in which a phosphor and a sealing resin are combined with an LED element, when a corrosive gas is generated, a silver electrode provided on the device is likely to be discolored. Since the silver electrode also plays a role of efficiently reflecting the light from the LED element and the phosphor, the reflectance decreases due to the discoloration, and further causes a great problem that the brightness of the LED light emitting device itself is decreased. End up.

  In order to solve such a problem, a method for preventing contact between the sulfide phosphor and moisture has been proposed. For example, Patent Document 1 describes a method in which a discontinuous glass film having a thickness of 20 nm or more is provided on the surface of sulfide phosphor particles using alkoxysilane, a silane organometallic compound. However, in this method, since water for hydrolysis is simultaneously added to the sulfide phosphor particles together with alkoxysilane, the sulfide phosphor particles themselves deteriorate due to the influence of moisture, and the deterioration becomes more severe when the heating temperature is increased. In a severe case, there is a drawback that the phosphor particles are dissolved.

  In Patent Document 2, an organic polymer film containing silicone is formed on the surface of sulfide phosphor powder using an organosilane compound, and the organic polymer film is heat-treated to obtain a silicone oxide film. A method has been proposed. However, in this method, ammonia added as a reaction catalyst promotes the hydrolysis reaction of the organic silane compound. On the other hand, the organic silane compounds undergo a condensation reaction before coating the phosphor particle surface, and the organic silane Condensate fine particles of the compound are produced. Even if the sulfide phosphor powder on which the fine particles are deposited is heat-treated, the formed film does not become dense, and improvement in water resistance and moisture resistance cannot be obtained.

  On the other hand, there is an attempt to completely block reaction with moisture by providing a thick coating film on the surface of the phosphor particles. For example, Patent Document 3 proposes a method of providing a coating film on the surface of phosphor particles using a coating material such as silicone resin, tetraethoxysilane, silica, zinc silicate, aluminum silicate, silicone oil, silicone grease, and the like. Has been. Although this method is a simple method, it is not easy to uniformly cover the entire surface of the fine phosphor particles with the coating material or to control the thickness of the coating film.

  In the case of sulfide phosphor particles using the moisture resistance and water resistance improvement measures described in Patent Documents 1 to 3 above, it is not sufficient to evaluate the moisture resistance and water resistance of the obtained sulfide phosphor particles with a coating film. I found out. For example, if the above-mentioned sulfide phosphor with a coating film is placed in a high-temperature humidified atmosphere, the surface of the phosphor particles is affected by the influence of humidity, and hydrates, sulfates or carbonates are generated, resulting in a significant decrease in light emission characteristics. did. Furthermore, when the above-mentioned sulfide phosphor particles with a coating film were kneaded with a silicone resin and put into high-temperature water after heat curing, a significant amount of gas was generated due to the reaction between moisture and sulfide. When the generated gas was evaluated by the discoloration of the silver plate, the discoloration of the silver plate started immediately after the phosphor kneaded in the resin was put into water, and the reflectance on the surface of the silver plate decreased drastically in a short time.

  Further, Patent Document 4 proposes a curable silicone resin composition in which a sulfide phosphor is surface-treated with hydroalkoxysilane or an oligomer thereof and then mixed with an addition-curable silicone resin made of an organopolysiloxane. According to this method, it is said that the LED chip sealed with the cured product of the silicone resin composition has improved long-term moisture resistance.

  However, in the method described in Patent Document 4, it has been found that when the sulfide phosphor and the hydroalkoxysilane or oligomer thereof are brought into direct contact and then heat-treated, the light emission characteristics are significantly reduced. In addition, when the moisture resistance was evaluated over a long period of time, a decrease in the light emission characteristics was observed, and the humidity countermeasures were incomplete. Furthermore, in LED chips sealed with a cured product of the above silicone resin composition, there is a difference in moisture resistance even with a thermosetting silicone resin. Therefore, when a discoloration evaluation of a silver plate is performed using a sulfide phosphor, the resin It turned out that a big difference arises by.

JP 2005-187797 A JP 2007-308537 A JP 2006-188700 A JP 2010-248411 A

  In view of the above-mentioned conventional problems, the present invention forms a coating film on the surface of sulfide phosphor particles without deteriorating the light emission characteristics, and then mixes with a sealing resin and cures to form a sulfide. Cured silicone resin containing sulfide phosphor particles with a coating film and its production capable of maintaining the original light emission characteristics of the phosphor and maintaining high moisture resistance and water resistance over a long period of time It aims to provide a method.

  In order to achieve the above object, as a result of intensive investigations, the present inventors first bonded or adsorbed a coating material prepared from a mercapto group-containing silane organometallic compound on the surface of the sulfide phosphor particles in the coating treatment. Forming a base layer, bonding or adsorbing a coating material prepared from a silane organometallic compound thereon to form a coating film, and then heat-treating the laminated coating film in the atmosphere to form an amorphous layer By using a coating film of an inorganic oxide, sulfide phosphor particles having a coating film having excellent moisture resistance and water resistance and high adhesion can be obtained without reducing the emission intensity. It was confirmed.

Furthermore, in order to eliminate the discoloration of the silver electrode by suppressing the generation of hydrogen sulfide gas due to the reaction with moisture when the sulfide phosphor particles provided with this coating film are resin-sealed and used in LED light-emitting devices. Is a blend of a resin component dimethylphenylsiloxane and polymethylhydroxysiloxane and a curing catalyst containing a fatty acid group, and the oxygen permeability after curing is 600 cm ³ · cm / m ² · 24 hr · atm or less, Obtaining knowledge that it is effective to use a thermosetting silicone resin having a tensile strength of 1 MPa to 10 MPa, the present invention has been completed.

That is, the coating film with sulphide phosphor particle-containing silicone resin cured product according to the present invention, a silicone resin formulation is cured with a curing catalyst comprising a mixture and a fatty acid radical of two-liquid type thermosetting silicone resin , contained therein, organometallic hydrolytic condensate derived from Si, Al, coating with a sulfide whose surface is coated with a coating film of two layers of amorphous inorganic oxide composed mainly of O a cured product of the silicone resin containing the phosphor particles, the cured oxygen permeability of the silicone resin is 600cm ³ · ^cm / m and the tensile strength at 2 · 24hr · atm or less is 1MPa～10MPa, the sulfide phosphor mercapto-containing silane organometallic hydrolysis condensation of the first layer of the coating film weight average molecular weight of 1,000 to 10,000 of the coating film of the particle surface to be coated two-layer Amorphous inorganic acid derived from products A product, homogeneous silane organic of said sulfide phosphor second layer of the coating film of the coating film of the particle surface to be coated two-layer heavy weight average molecular weight 5,000 to 20,000 It is an amorphous inorganic oxide derived from a metal hydrolysis condensate.

Moreover, the manufacturing method of the sulfide fluorescent substance particle containing silicone resin hardening body with a coating film by this invention includes each process of following (1)-(4), It is characterized by the above-mentioned. (1) Coating a mercapto group-containing silane organometallic compound having a weight average molecular weight of 1,000 to 10,000 by hydrolyzing a mercapto group-containing silane organometallic compound with an aluminum organometallic compound as a catalyst, an organic solvent and water. A first step of preparing a first coating film on the surface of the sulfide phosphor particles by preparing a material and stirring and mixing the coating material and the sulfide phosphor particles in a container;
(2) A silane organometallic compound is hydrolyzed with an aluminum organometallic compound as a catalyst, an organic solvent and water to prepare a coating material for a silane organometallic hydrolyzed condensate having a weight average molecular weight of 5,000 to 20,000. Uniform coating of the second layer on the surface of the sulfide phosphor particles by stirring and mixing the coating material and the sulfide phosphor particles having the coating film of the first layer obtained in the first step in a container Second step of forming a film.
(3) The sulfide phosphor particles having the first layer and the second layer coating film obtained in the second step are heat-treated in the atmosphere, and Si, Al, A third step of obtaining sulfide phosphor particles with a coating film having a coating film of an amorphous inorganic oxide mainly containing O.
(4) The sulfide phosphor particles with a coating film obtained in the third step are blended with a curing catalyst containing a fatty acid group in a mixture of two-component thermosetting silicone resin , and the oxygen permeability after curing There ^{600cm 3 · cm / m 2 ·} 24hr · atm or less and a tensile strength kneading was admixed with the thermosetting silicone resin of 1MPa～10MPa, by heat curing at 110 to 150 ° C. in air, the A fourth step of obtaining a cured silicone resin-containing sulfide phosphor particle-containing film.

  In the cured silicone resin containing sulfide phosphor particles having a coating film according to the present invention and the method for producing the same, the mercapto group-containing silane organometallic compound is selected from 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane. It is preferable that at least one selected. The silane organometallic compound is preferably at least one selected from methyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, and n-propyltrimethoxysilane. Further, the aluminum organometallic compound is at least one selected from ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), octyl acetoacetate aluminum diisopropylate, and aluminum monoacetylacetonate bis (ethyl acetoacetate). Preferably it is a seed.

  According to the present invention, the first coating film as a base layer provides high coverage and excellent adhesion, and a second coating film is further laminated thereon to heat treatment. By doing so, it is possible to form a dense and uniform coating film having almost no defects and having high adhesion with an amorphous inorganic oxide mainly composed of Si, Al and O. It is possible to obtain a coated phosphor sulfide particle having excellent moisture resistance and water resistance while maintaining the light emission characteristics.

  In addition, the coated phosphor sulfide particles with high moisture resistance and water resistance and excellent light emitting properties are obtained by adding and mixing the sulfide phosphor particles with a coating film in a silicone resin and curing by heating. A cured product of a silicone resin containing can be provided. In addition, the cured silicone resin containing a sulfide phosphor with a coating film can not only maintain excellent moisture resistance and light emission characteristics over a long period of time, but also has a high translucency of the resin, so the emission intensity of the sulfide phosphor is high. There is no decline.

  Accordingly, the cured silicone resin containing sulfide phosphor particles with a coating film according to the present invention has extremely high moisture resistance and water resistance, can maintain the original emission intensity of the phosphor, and is corrosive due to reaction with water vapor and moisture. Since generation of hydrogen sulfide gas can be suppressed, it is extremely excellent as a cured silicone resin containing a sulfide phosphor used in LED light emitting devices. In addition, the method for producing a cured silicone resin containing a sulfide phosphor particle with a coating film according to the present invention has no special operation in each step and equipment to be used, and can be produced easily and efficiently. It is also very good.

  The cured silicone resin containing sulfide phosphor particles with a coating film according to the present invention is a silicone resin in which a curing catalyst containing a fatty acid group is blended with a mixture of resin components dimethylphenylsiloxane and polymethylhydroxysiloxane and cured. In addition, the first and second layer organometallic hydrolyzed condensate coating films formed on the particle surface are heat-treated in the atmosphere to form amorphous inorganic oxides mainly composed of Si, Al, and O. This is a cured body of a silicone resin containing sulfide phosphor particles with a coating film provided with a coating film of the product.

The sulfide phosphor particles used as the core material of the sulfide phosphor particles with a coating film are composed of sulfur (S), calcium (Ca), strontium (Sr), gallium (Ga) and europium (Eu) as constituent elements. Any compound may be used as long as it contains at least one selected element. Preferably, the compound is represented by a composition formula of CaS: Eu, SrS: Eu, (Ca, Sr) S: Eu, SrGa ₂ S ₄ : Eu. At least one selected from phosphor particles containing a phase can be used. The average particle diameter (D50) of the sulfide phosphor particles is preferably in the range of 1 μm to 50 μm.

  The coating film of the first layer formed on the surface of the sulfide phosphor particles is a weight average obtained by hydrolyzing a mercapto group-containing silane organometallic compound with an aluminum organometallic compound as a catalyst, an organic solvent and water. It is a mercapto group-containing silane organometallic hydrolysis condensate having a molecular weight of 1,000 to 10,000. The coating film of the second layer is a silane organometallic hydrolyzate having a weight average molecular weight of 5,000 to 20,000 obtained by hydrolyzing a silane organometallic compound with an aluminum organometallic compound as a catalyst, an organic solvent and water. It is a decomposition condensate.

  Amorphous inorganic oxide coating film comprising Si, Al, and O as main components obtained by heat-treating the coating films of the first layer and the second layer organometallic hydrolysis condensate in the air Is preferably in the range of 50 to 200 nm. This is because it is difficult to obtain sufficient moisture resistance and water resistance when the film thickness of the amorphous inorganic oxide coating film is less than 50 nm. In addition, when the film thickness exceeds 200 nm, not only is it disadvantageous in terms of cost, but also light emission of LED light-emitting devices produced with the phosphor particles tends to occur, which is not preferable.

On the other hand, silicone resin containing dispersed phosphor phosphor particles with a coating film is a thermosetting silicone resin in which a curing catalyst containing a fatty acid group is blended with a mixture of resin components dimethylphenylsiloxane and polymethylhydroxysiloxane. Thus, it is necessary that the oxygen permeability after the curing is 600 cm ³ · cm / m ² · 24 hr · atm or less and the tensile strength is 1 MPa to 10 MPa. The low oxygen permeability of the cured silicone resin is effective in suppressing moisture intrusion from the outside air, and the tensile strength of 1 MPa to 10 MPa indicates appropriate adhesion and flexibility with the phosphor particles. ing. Therefore, by adopting the silicone resin having the above characteristics, it is possible to dramatically improve the moisture resistance and water resistance of the cured silicone resin containing sulfide phosphor particles with a coating film as compared with the conventional one.

  The above-described sulfide phosphor particle-containing silicone resin cured body with a coating film of the present invention can be produced by a method comprising the following steps (1) to (4).

  (1) Mercapto group-containing silane organometallic compound is hydrolyzed with a catalyst aluminum organometallic compound, an organic solvent, and water to hydrolyze a mercapto group-containing silane organometallic compound having a weight average molecular weight (Mw) of 1,000 to 10,000. A first step of preparing a condensate coating material, and stirring and mixing the coating material and sulfide phosphor particles in a container to form a first layer coating film on the surface of the sulfide phosphor particles.

  (2) A coating material of a silane organometallic hydrolysis condensate having a weight average molecular weight (Mw) of 5,000 to 20,000 by hydrolyzing a silane organometallic compound with an aluminum organometallic compound as a catalyst, an organic solvent and water. By adjusting and mixing the covering phosphor and the sulfide phosphor particles having the first layer coating film obtained in the first step in the container, the second layer is formed on the surface of the sulfide phosphor particles. Second step of forming a coating film.

  (3) The sulfide phosphor particles having the first layer and the second layer coating film obtained in the second step are heat-treated in the atmosphere, and Si, Al, A third step of obtaining sulfide phosphor particles with a coating film having a coating film of an amorphous inorganic oxide mainly containing O.

(4) The coating-coated sulfide phosphor particles obtained in the third step are blended with a curing catalyst containing a fatty acid group in a mixture of resin components dimethylphenylsiloxane and polymethylhydroxysiloxane, and oxygen after curing. By adding and kneading to a thermosetting silicone resin having a transmittance of 600 cm ³ · cm / m ² · 24 hr · atm or less and a tensile strength of 1 MPa to 10 MPa, and heat-curing at 110 to 150 ° C. in the atmosphere. And a fourth step of obtaining a cured silicone resin containing sulfide phosphor particles with a coating film.

  Next, the method for producing the above-described coated phosphor-containing sulfide phosphor particle-containing cured silicone resin will be described in more detail for each step.

  (1) In the first step, a mercapto group-containing silane organometallic compound having a weight average molecular weight of 1,000 to 10,000 is hydrolyzed with an aluminum organometallic compound, an organic solvent, and water. A coating material of the decomposition condensate is prepared, and this coating material and sulfide phosphor particles are stirred and mixed in a container to form a first layer coating film on the surface of the sulfide phosphor particles.

  First, a mercapto group-containing silane organometallic compound, an aluminum organometallic compound that acts as a catalyst, and water for hydrolysis are added to an organic solvent and hydrolyzed to obtain a weight average molecular weight of 1,000 to 10,000. The coating material of the mercapto group-containing silane organometallic hydrolysis condensate is prepared.

  Mercapto group-containing silane organometallic compounds have a molecular weight gradually increasing with the progress of hydrolysis and condensation over time due to the action of aluminum organometallic compound acting as a catalyst and water for hydrolysis. The weight average molecular weight is adjusted and controlled to reach 1,000 to 10,000. If the weight average molecular weight of the coating material is less than 1,000, the adsorptivity to the particle surface is lowered and an undercoat layer cannot be obtained. Conversely, even if the weight average molecular weight exceeds 10,000, the adsorptivity decreases. End up. When the formation of the underlayer is insufficient, the covering properties of the coating film to be laminated are lowered and the moisture resistance and water resistance are not improved. Therefore, it is important to set the weight average molecular weight to 1,000 to 10,000. It is.

  As the mercapto group-containing silane organometallic compound, those having compatibility with the organic solvent to be used and having a high adsorptive power to the surface of the sulfide phosphor particles are desirable. As a specific mercapto group-containing silane organometallic compound, it is preferable to use at least one selected from 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane. Moreover, as an organic solvent, alcohol solvents, such as ethanol and isopropyl alcohol, are preferable. Toluene, heptane, or the like can be mixed with 1 part of the alcohol solvent.

  As the aluminum organometallic compound, an aluminum chelate compound having an alkyl group is preferable. Specifically, ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), octyl acetoacetate aluminum diisopropylate, aluminum monoacetylacetate There is at least one selected from bis (ethyl acetoacetate). In particular, ethyl acetoacetate aluminum diisopropylate having high compatibility with an organic solvent is more preferable.

  The compounding ratio of the mercapto group-containing silane organometallic compound, aluminum organometallic compound, organic solvent and water is 0.2 to 1 part by mass of organic solvent and aluminum organometallic with respect to 1 part by mass of mercapto group-containing silane organometallic compound. It is preferable that the compound is 0.0125 to 0.05 parts by mass and the water is 0.005 to 0.2 parts by mass. When the amount of the organic solvent is more than 1 part by mass, the concentration time becomes longer, and when the amount is less than 0.2 part by mass, the mixing becomes uneven. Further, when the amount of the aluminum organometallic compound is less than 0.0125 parts by mass, the catalytic action tends to be insufficient. It is not preferable because it tends to aggregate and form a coarse precipitate in the solvent. If the amount of water is less than 0.005 parts by mass, the hydrolysis reaction hardly proceeds, and if it exceeds 0.2 parts by mass, phosphor particles may be deteriorated, which is not preferable.

  As a specific operation, a mercapto group silane organometallic compound, an aluminum organometallic compound, an organic solvent and water are blended, and a hydrolysis condensate is produced by stirring for 1 to 6 hours in a sealed state. As conditions for stirring and mixing, the temperature is preferably 18 to 80 ° C, more preferably 18 to 60 ° C, and particularly preferably 20 to 40 ° C. If the temperature is lower than 18 ° C., the reaction becomes insufficient. If the temperature is higher than 80 ° C., the reaction becomes too vigorous and white turbidity or precipitate is formed. In addition, there is no restriction | limiting in particular in the means of stirring mixing, It can carry out by the method using stirring machines, such as a stirring blade and a stirrer, or the method using an ultrasonic homogenizer.

  The coating material for forming the underlayer obtained in the first step is a mercapto group-containing silane organometallic hydrolysis condensate having a weight average molecular weight (Mw) of 1,000 to 10,000. The weight average molecular weight can be measured by gel permeation chromatography analysis (GPC analysis). Specifically, 2 cc of a covering material was collected as a measurement sample, 18 cc of tetrahydrofuran was added to the sample, and the mixture was stirred and filtered, and then evaluated by measuring the weight average molecular weight.

  Next, the coating material of the mercapto group-containing silane organometallic hydrolysis condensate having a weight average molecular weight of 1,000 to 10,000 prepared as described above is agitated and mixed with sulfide phosphor particles in a container, thereby sulfiding. A first coating layer is formed on the surface of the phosphor particles.

  In general, a mercapto group-containing silane organometallic compound and a hydrolysis-condensation product thereof have a mercapto group and an alkoxy group at the molecular ends. By combining the mercapto group with the sulfur component on the surface of the sulfide phosphor particle, a first layer of a mercapto group-containing silane organometallic hydrolysis condensate of the first layer is formed. At this time, mercapto groups are arranged on the inner side (particle surface side) of the underlayer, and alkoxy groups are oriented on the outer side. Then, a second layer coating film is laminated on the first layer, which is the first layer. At this time, the second layer coating film is bonded to the hydroxyl group of the silane organometallic hydrolysis condensate. Therefore, the bonding is easily performed due to the presence of an alkoxy group on the surface of the base layer.

  The blending ratio of the sulfide phosphor particles and the mercapto group-containing silane organometallic hydrolysis condensate is not particularly limited, but is 0.01 to 1 part by mass of mercapto with respect to 1 part by mass of the sulfide phosphor particles. It is preferable to mix a group-containing silane organometallic hydrolysis condensate. When the amount of the mercapto group-containing silane organometallic compound exceeds 1 part by mass, aggregation of the phosphor particles tends to occur during the separation of the organic solvent, which is not preferable. On the other hand, if the mercapto group-containing silane organometallic hydrolysis condensate is less than 0.01 parts by mass, the effect as the underlayer becomes insufficient, such being undesirable.

  As a specific operation, a coating material of a mercapto group-containing silane organometallic hydrolysis condensate having a weight average molecular weight of 1,000 to 10,000 prepared as described above, ethanol, isopropyl alcohol, 1-butanol alcohol solvent, Alternatively, the mixture is mixed with an organic solvent such as a hydrocarbon solvent such as heptane or toluene, and further, sulfide phosphor particles are added, and 28 to 48 kHz ultrasonic vibration is added for 5 to 30 minutes to disperse. Subsequently, the mixture is stirred and mixed at a temperature of 18 to 80 ° C. for 0.5 to 24 hours in a sealed state. Thereafter, the organic solvent is separated by vacuum filtration to obtain sulfide phosphor particles on which a first layer coating film as a base layer is formed.

  (2) In the second step, a silane organometallic compound is hydrolyzed with an aluminum organometallic compound, an organic solvent, and water to obtain a coating material of a silane organometallic compound hydrolyzed condensate having a weight average molecular weight of 5,000 to 20,000. The second layer coating film is formed on the surface of the sulfide phosphor particle having the first layer coating film by using this coating material.

  First, a silane organometallic compound, an aluminum organometallic compound that acts as a catalyst, and water for hydrolysis are blended in an organic solvent and hydrolyzed to give a silane organic compound having a weight average molecular weight of 5,000 to 20,000. A metal hydrolysis condensate is obtained.

  Silane organometallic compounds undergo hydrolysis and condensation reactions with the action of aluminum organometallic compounds and water, and condensation gradually progresses over time, and the molecular weight gradually increases. The range is from 5,000 to 20,000, preferably from 7,000 to 12,000. When the weight average molecular weight is less than 5,000, the amount of scattering during the heat treatment increases, and thus a dense coating film cannot be obtained. On the other hand, when the weight average molecular weight exceeds 20,000, the coating property on the surface of the phosphor particles is lowered, and the moisture resistance and water resistance are not improved.

  As the silane organometallic compound used for the preparation of the coating material for the second layer, trialkoxysilane can be suitably used from the viewpoints of stability of the hydrolyzed condensate, coating properties and film quality. Specific examples include trialkoxysilanes such as methyl-, ethyl-, i-propyl-, i-butyl-, n-propyl-, n-butyl-. Among these, methyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, and n-propyltrimethoxysilane are preferable, and methyltrimethoxysilane or methyltriethoxysilane is particularly preferable. Since methyltrimethoxysilane and methyltriethoxysilane have an appropriate reaction rate, the viscosity does not increase suddenly even in the production of hydrolysis condensates over a long period of time, and instability such as the formation of precipitates or clouding occurs. This is because it is easy to control the molecular weight to a desired level.

  As the aluminum organometallic compound used for the preparation of the coating material for the second layer, the aluminum organometallic compound mentioned in the first step can be preferably used, and among them, ethyl acetoacetate aluminum dihydrate having high compatibility with the organic solvent. Isopropylate is particularly preferred. Moreover, as an organic solvent, alcohol solvents, such as ethanol and isopropyl alcohol, are preferable.

  The mixing ratio of the silane organometallic compound, the aluminum organometallic compound, the organic solvent and water is 0.5 to 1 part by mass for the organic solvent and 0.0125 for the aluminum organometallic compound with respect to 1 part by mass of the silane organometallic compound. It is preferable that 0.05 mass part and water are 0.2-0.5 mass part. When the amount of the organic solvent is more than 1 part by mass, the concentration time becomes longer, and when the amount is less than 0.5 part by mass, the mixing becomes uneven. Further, when the aluminum organometallic compound is less than 0.0125 parts by mass, the catalytic action tends to be insufficient. Conversely, when the aluminum organometallic compound exceeds 0.05 parts by mass, the reaction becomes too active, and the produced silane organometallic hydrolyzed condensates are in contact with each other. Aggregates and tends to form coarse precipitates in the solvent. If the water content is less than 0.2 parts by mass or exceeds 0.5 parts by mass, the hydrolysis reaction becomes unstable, which is not preferable.

  As a specific operation method, a silane organometallic compound, an aluminum organometallic compound, an organic solvent and water are blended and stirred for 18 to 96 hours in a sealed state to produce a silane organometallic hydrolysis condensate. The solution of the obtained silane organometallic hydrolysis condensate is put into an opened container, and the amount of liquid is 80% of the original mass by vigorous evaporation of excess solvent, moisture and unreacted substances. Concentrate to ~ 60%. After the concentration is completed, vacuum filtration is performed at a vacuum degree of 0.05 to 0.1 MPa to obtain a coating material for the second layer of the silane organometallic hydrolysis condensate.

  Although it does not specifically limit as stirring and mixing conditions in the case of the said hydrolysis condensation, Temperature is preferably 18-40 degreeC under a sealing state. If the temperature is lower than 18 ° C., the reaction becomes insufficient. If the temperature is higher than 40 ° C., the reaction becomes too vigorous and white turbidity or precipitate is formed.

  The stirring time is preferably 18 to 96 hours. If the stirring time is less than 18 hours, the hydrolysis condensation reaction is insufficient, and the hydrolysis condensate contains many low molecules, so the resistance to heat or water is poor and it functions as a good coating film. May not. On the other hand, when the stirring time exceeds 96 hours, the adsorptivity at the time of forming the coating film is inferior, and an uncoated portion tends to be locally generated. As a means for stirring and mixing, a method using a stirring machine such as a stirring blade or a stirrer, or a known method such as an ultrasonic homogenizer can be used.

  Next, the second layer coating material that is the silane organometallic hydrolysis condensate prepared as described above is used as the sulfide phosphor in which the first layer coating film that is the base layer is formed in the first step. By stirring and mixing the particles in the container, a second coating film is laminated on the first coating film on the surface of the sulfide phosphor particles.

  The blending ratio of the sulfide phosphor particles and the coating material of the second layer is preferably 1 to 6 parts by mass of the coating material of the silane organometallic hydrolysis condensate with respect to 1 part by mass of the phosphor particles. If the coating material of the silane organometallic hydrolysis-condensation product is less than 1 part by mass, the amount of filtration increases and waste is increased. On the contrary, when the coating material of the silane organometallic hydrolysis condensate is more than 6 parts by mass, the agitation tends to be insufficient and it becomes difficult to form a good coating film, which is not preferable.

  Specifically, the second layer coating material, which is a silane organometallic hydrolysis condensate, and the sulfide phosphor particles on which the first layer coating film was formed were mixed in a container and obtained. The mixture is subjected to ultrasonic vibration and redispersed, and then stirred and mixed at a temperature of 18 to 100 ° C. for 0.2 to 24 hours. Thereafter, vacuum filtration and drying at 100 to 120 ° C. in the atmosphere allows the sulfide phosphor particles having the second coating film on the first coating film as the underlayer. can get.

  (3) In the third step, the sulfide phosphor particles having the first layer and the second layer coating film obtained in the second step are heat-treated in the atmosphere, thereby producing sulfide fluorescence. A sulfide phosphor particle with a coating film having a coating film of an amorphous inorganic oxide mainly containing Si, Al, and O on the body particle surface is obtained.

  That is, the first layer of the mercapto group-containing silane organometallic hydrolysis condensate laminated on the surface of the sulfide phosphor particles by heat-treating the sulfide phosphor particles obtained in the second step in the air. The coating film of the eye and the second coating film of the silane organometallic hydrolysis condensate are mainly composed of Si, Al, and O when the organic matter contained therein is thermally decomposed to become inorganic. Thus, the denseness of the resulting amorphous inorganic oxide coating film can be improved.

  The atmosphere for the heat treatment is not particularly limited, and may be an air atmosphere, an inert gas, a vacuum, or a combination of these. As the temperature of the heat treatment, the higher the heating temperature, the denser and stronger the coating film of the amorphous inorganic oxide tends to improve the moisture resistance, but it also affects the heat resistance of the sulfide phosphor particles. Therefore, the range of 200 to 300 ° C. is preferable. The heating time is preferably 0.5 to 2 hours.

  Through the above first to third steps, the coated phosphor-coated sulfide phosphor particles according to the present invention can be produced. The film thickness of the coating film made of an amorphous inorganic oxide is preferably 50 to 200 nm. If the film thickness of the coating film is less than 50 nm, it is difficult to obtain sufficient moisture resistance and water resistance. Moreover, when the film thickness of the coating film exceeds 200 nm, not only is it disadvantageous in cost, but also the light emission of the LED light-emitting device produced from the obtained sulfide phosphor particles with a coating film tends to vary. Therefore, it is not preferable.

  (4) In the final fourth step, the coated phosphor-coated sulfide phosphor particles obtained in the third step are added and mixed into a thermosetting silicone resin, kneaded, and heated and cured in the atmosphere. Then, a cured silicone resin containing sulfide phosphor particles with a coating film is obtained.

As already described, the thermosetting silicone resin used in the fourth step is a thermosetting silicone in which a mixture of dimethylphenylsiloxane and polymethylhydroxysiloxane, which are resin components, is blended with a curing catalyst containing a fatty acid group. The resin is required to have an oxygen permeability after curing of 600 cm ³ · cm / m ² · 24 hr · atm or less and a tensile strength of 1 MPa to 10 MPa. In addition, as a curing catalyst containing a fatty acid group, for example, fatty acid zinc or fatty acid tin can be used.

Examples of the thermosetting silicone resin that can be suitably used in the fourth step include OE-6665 (oxygen permeability: 500 cm ³ · cm / m ² · 24 hr · atm, manufactured by Toray Dow Corning Co., Ltd., tensile strength: 8.9 MPa), ASP-1010 manufactured by Shin-Etsu Chemical Co., Ltd. (oxygen permeability: 200 cm ³ · cm / m ² · 24 hr · atm, tensile strength: 6.2 MPa) and ASP-1020 A / B (oxygen permeability 320 cm) ³ · cm / m ² · 24 hr · atm: tensile strength: 2.5 MPa).

  Further, the blending ratio of the sulfide phosphor particles with a coating film and the thermosetting silicone resin is 5 to 50 parts by mass of the sulfide phosphor particles with a coating film with respect to 100 parts by mass of the thermosetting silicone resin. It is preferable to do. If the blending amount of the sulfide phosphor particles with a coating film is less than 5 parts by mass, the blending ratio of the phosphor particles in the resin is low. , Since the effect of moisture resistance and water resistance by the resin is lowered, it is not preferable.

  As a specific operation, first, the sulfide fluorescent substance with a coating film obtained in the third step is blended at a ratio of 5 to 50 parts by mass with respect to 100 parts by mass of the thermosetting silicone resin, and then vacuum desorption is performed. Mix and knead while foaming. The mixing and kneading of the sulfide phosphor particles with a coating film and the silicone resin are performed by stirring for 1 to 10 minutes using an ordinary resin mixer such as ARV-3101ED manufactured by Shinky Corporation.

  The liquid viscosity of the silicone resin when mixed with the sulfide phosphor particles with a coating film is preferably in the range of 400 to 5,000 mPa · s. When the viscosity is less than 400 Pa · s, sedimentation of the sulfide phosphor particles with a coating film occurs immediately after kneading the resin. Further, when the viscosity exceeds 5,000 mPa · s, it takes a long time for kneading or an excessive force needs to be applied at the time of kneading. When the viscosity of the silicone resin is out of the above range, it is desirable to adjust the viscosity by adding a viscosity adjusting agent.

  After mixing and kneading the sulfide phosphor with a coating film and the thermosetting silicone resin, an appropriate amount of the kneaded resin obtained was cast into a glass or metal mold and 110 to 150 in the atmosphere. Heat cure at ℃. When the heat curing temperature is less than 110 ° C., the resin strength is lowered due to insufficient curing of the resin. On the other hand, if it exceeds 150 ° C., the resin is degraded and deteriorated, which is not preferable.

  By the first to fourth steps described above, the cured silicone resin-containing sulfide phosphor particles with a coating film of the present invention can be obtained. In the cured silicone resin containing a sulfide phosphor particle with a coating film of the present invention thus obtained, the sulfide phosphor particle with a coating film excellent in moisture resistance and water resistance and a carefully selected silicone resin are used. The combination suppresses moisture intrusion from the outside air, and at the same time, provides appropriate adhesion and flexibility between the sulfide phosphor particles and the silicone resin, and can drastically improve the overall moisture resistance and water resistance. .

  In the cured silicone resin containing sulfide phosphor particles with a coating film according to the present invention, it is necessary to pay attention to the following points in order to sufficiently exhibit the effect. (A) If the formation of the first coating film as the underlayer is not uniform, the formation of the second coating film laminated thereon is insufficient and the water resistance is not improved. (B) If the coating film is not densified by heat treatment, the coating film is peeled off when kneaded into the resin, and the phosphor particles undergo a reaction when the resin is heat-cured to deteriorate the light emission characteristics. (C) Some silicone resin components have Si-H groups, but highly reactive Si-H groups may react with phosphor particles during heat curing, and the particle surface is analyzed. It can be confirmed as a different phase. Further, when sulfide phosphor particles are kneaded into a silicone resin and heated without forming an underlayer or a coating film, the resin may not be cured.

The following examples and comparative examples illustrate the present invention in more detail. In each of the examples and comparative examples, SrGa ₂ S ₄ : Eu particles (manufactured by High-Purity Chemical Co., Ltd., average particle size D50 = 5.6 μm) were used as sulfide phosphor particles serving as a core material. . In Examples and Comparative Examples, the film thickness, adhesion, and light emission characteristics (change in emission intensity before and after coating) of the phosphor particles with coating film, and moisture resistance of the phosphor particles with coating film The water resistance (change in silver plate reflectivity) of the cured resin containing phosphor particles with a coating film (change in emission intensity before and after the moisture resistance test) was evaluated by the following method.

<Evaluation of coating film thickness>
A part of the phosphor particles with a coating film is taken out and embedded in an epoxy resin, the cross section is processed after curing, and the cross section is observed by SEM or TEM. The dimension of the coating film (n = 5) was measured from the obtained image, and the average film thickness was obtained. At that time, since the contrast of the coating film can be changed due to the difference in composition, it can be clearly observed in the secondary electron image and the reflected electron image. In addition, since Si and O are detected when the coating film is analyzed by SEM-EDX, it can be confirmed that the film observed by shading is due to the coating.

<Evaluation of coating film adhesion>
10 g of phosphor particles with a coating film are added to 20 to 90 g of silicone resin (differs depending on examples or comparative examples), and 1200 rpm × 10 minutes while performing vacuum defoaming with a stirring mixer (ARV310-LED, manufactured by Sinky Corporation) Was vacuum stirred. The obtained kneaded resin was weighed by 1 g and cast into 20 glass molds having a diameter of 40 mm. Curing is performed at 150 ° C. for 2 hours, and a part of the obtained coated resin-coated phosphor particle-containing resin cured product is subjected to cross-sectional processing and cross-sectional observation with TEM is performed, film cracking or peeling of the coating film Those with no mark are indicated with “◯”, and those with film cracking or peeling are indicated with “x”.

<Emission characteristic evaluation of phosphor particles with coating film>
PL (Photo Luminescence) emission intensity before and after the formation of the coating film of phosphor particles was measured, and the change in PL emission intensity before and after the formation of the coating film (PL emission intensity after coating / PL emission intensity before coating) It was confirmed. By comparing the PL emission intensity before and after the coating process, you can see changes such as a decrease in PL emission intensity due to the influence of moisture during the coating process, and an increase in PL emission intensity due to film formation or particle surface purification effects, etc. Can do. In addition, PL emission intensity was calculated | required from the intensity | strength of the emission spectrum with the excitation light of 450 nm with the spectrofluorimeter FP6500 by JASCO Corporation.

<Moisture resistance evaluation of phosphor particles with coating film>
The PL emission intensity before and after the moisture resistance test of the phosphor particles with the coating film was measured, and the change (PL emission intensity after the moisture resistance test / initial PL emission intensity) was determined. The moisture resistance test was carried out by using a phosphor-containing resin-cured resin particle with a coating film produced in the same manner as in the evaluation of the adhesiveness of the coating film, and holding it in an atmosphere of 85 ° C. × 85% RH for 250 hours. In addition, PL emission intensity was calculated | required from the intensity | strength of the emission spectrum with the excitation light of 450 nm with the spectrofluorimeter FP6500 by JASCO Corporation.

<Water resistance evaluation of the cured resin containing phosphor particles with coating film>
Evaluation was carried out using a coated resin-coated phosphor particle-containing resin cured body prepared in the same manner as the evaluation of the adhesion of the coating film. The cured resin containing phosphor particles with a coating film was placed in a bottle with an opening diameter of 8 cm together with 100 ml of water, sealed with a lid with a 3 cm square pure silver plate on the inside, and heated to 80 ° C. After 40 minutes, the reflectance of the silver plate surface was measured to evaluate the degree of generation of hydrogen sulfide gas due to the reaction between the phosphor particles and moisture. For the change in reflectance, the reflectance of the silver plate before the heat treatment was taken as 1, and the reflectance after the heat treatment was evaluated as a relative value. In addition, the reflectance calculated | required the diffuse reflectance with Shimadzu Corporation spectrophotometer UV2450, and compared the numerical value at the time of the measurement in wavelength 450nm.

[Example 1]
According to the following 1st process-4th process, the sulfide fluorescent substance particle containing resin hardening body with a coating film was produced.

(First step)
To 180 g of isopropyl alcohol (IPA; manufactured by Kanto Chemical Co., Ltd., reagent special grade), 200 g of 3-mercaptopropyltrimethoxysilane (M189, A189) was added and mixed. Furthermore, 5 g of ethyl acetoacetate aluminum diisopropylate (manufactured by Kawaken Fine Chemicals Co., Ltd., ALCH S75P: concentration 75% by mass) was added and stirred with a stirrer while maintaining the temperature at 30 ° C. Separately, 20 g of IPA (manufactured by Kanto Chemical Co., Ltd., special grade reagent) and 20 g of ion-exchanged water were added dropwise, and the mixture was stirred and mixed for 2 hours to hydrolyze. A covering material for the first layer of the product (Mw 7,600) was obtained.

Next, the total amount of the mercapto group-containing silane organometallic hydrolysis condensate coating material was added to and mixed with 200 g of isopropyl alcohol (IPA; manufactured by Kanto Chemical Co., Inc., reagent special grade). To this solution, 200 g of sulfide phosphor particles (SrGa ₂ S ₄ : Eu, manufactured by High Purity Chemical Co., Ltd., average particle diameter D50 = 5.6 μm) was added, and the treatment with ultrasonic waves at 28 kHz for 5 minutes was performed 3 Dispersed once. The dispersion was stirred and mixed at 60 ° C. for 3 hours, then returned to room temperature and allowed to stand for 14 hours. The dispersion was vacuum filtered to obtain sulfide phosphor particles adsorbing the first layer mercapto group-containing silane organometallic hydrolysis condensate as an underlayer.

(Second step)
1000 g of methyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd., Z-6366), 680 g of ethanol (manufactured by Kanto Chemical Co., Ltd., special grade reagent), and ethyl acetoacetate aluminum diisopropylate (manufactured by Kawaken Fine Chemical Co., Ltd.) , ALCH S75P (concentration: 75% by mass)) and 320 g of ion-exchanged water were added and stirred with a stirrer while maintaining the temperature at 23 ° C. This stirring and mixing was continued for 72 hours to obtain an organic solution (viscosity of 6 mPa · S) of the silane organometallic hydrolysis condensate. 500 g of an organic solution of silane organometallic hydrolysis condensate is taken out, stirred with a stirrer in an opened state and concentrated until the liquid volume becomes 70% of the original mass, and silane organometallic hydrolysis condensate (Mw 12,000) ) Of the second layer was obtained.

  Next, 350 g of this silane organometallic hydrolysis condensate coating material and sulfide phosphor particles adsorbing the first layer mercapto group-containing silane organometallic hydrolysis condensate as the underlayer obtained in the first step 100 g was mixed, and the mixture was redispersed by applying 48 kHz ultrasonic vibration for 5 minutes. The redispersed liquid was stirred and mixed at 60 ° C. for 3 hours, then returned to room temperature and allowed to stand for 14 hours. The re-dispersed liquid was vacuum filtered, and then heated and dried at a temperature of 110 ° C. for 1 hour to obtain sulfide phosphor particles in which a first layer and a second layer coating film were laminated.

(Third step)
The sulfide phosphor particles obtained by laminating the first layer and the second layer coating film obtained in the second step are heat-treated in the atmosphere at a temperature of 250 ° C. for 1 hour to obtain Si, Al Thus, a sulfide phosphor particle with a coating film having a coating film of an amorphous inorganic oxide mainly containing O was obtained.

(4th process)
10 g of sulfide phosphor particles with coating film obtained in the third step and 90 g of silicone resin (ASP-1020, manufactured by Shin-Etsu Chemical Co., Ltd.) were mixed with a mixer (ARV-310LED, manufactured by Shinky Corporation). Kneaded for 3 minutes. The obtained kneaded resin was weighed in units of 1 g and cast into 10 glass molds. Each obtained cast material was cured under the conditions of 150 ° C. × 2 hours to prepare a cured silicone resin containing sulfide phosphor particles with a coating film.

  Regarding the obtained sulfide phosphor particles with a coating film of Example 1, the film thickness and adhesion of the coating film, the change in emission intensity before and after coating, and before and after the moisture resistance test of the phosphor particles with coating film The moisture resistance due to the change in the emission intensity and the water resistance due to the reflectance of the silver plate of the coated resin-coated phosphor particle-containing resin cured body were evaluated, and the results are shown in Table 1 below.

[Example 2]
In the first step, in the same manner as in Example 1 except that the conditions for stirring and mixing the first layer coating material for forming the underlayer and the sulfide phosphor particles were set at 85 ° C. for 2 hours, A cured cured silicone resin containing sulfide phosphor particles with a coating film was prepared.

  The obtained sulfide phosphor particles with a coating film of Example 2 were evaluated in the same manner as in Example 1, and the results are shown in Table 1 below.

[Example 3]
In the second step, sulfide phosphor particles adsorbing the first layer of mercapto group-containing silane organometallic hydrolysis condensate as the underlayer obtained in the first step, and a coating material for the silane organometallic hydrolysis condensate A cured silicone resin containing sulfide phosphor particles with a coating film was prepared in the same manner as in Example 1 except that the stirring and mixing conditions for redispersing were changed to 85 ° C. for 2 hours.

  The obtained sulfide phosphor particles with a coating film of Example 3 were evaluated in the same manner as in Example 1, and the results are shown in Table 1 below.

[Example 4]
In the fourth step, the sulfide phosphor particles with coating film and the silicone resin are kneaded with 10 g of the sulfide phosphor particles with coating film, and OE-6665 made by Toray Dow Corning Co., Ltd. A cured cured silicone resin containing sulfide phosphor particles with a coating film was prepared in the same manner as in Example 1 except that the amount was 90 g.

  The obtained sulfide phosphor particles with a coating film of Example 4 were evaluated in the same manner as in Example 1 above, and the results are shown in Table 1 below.

[Example 5]
In the fourth step, the same procedure as in Example 1 was performed except that 20 g of ASP-1020 manufactured by Shin-Etsu Chemical Co., Ltd. was used when kneading the sulfide phosphor particles with a coating film and the silicone resin. A cured cured silicone resin containing sulfide phosphor particles with a coating film was prepared.

  The obtained sulfide phosphor particles with a coating film of Example 5 were evaluated in the same manner as in Example 1, and the results are shown in Table 1 below.

[Comparative Example 1]
200 g of 3-mercaptopropyltrimethoxysilane (A189, manufactured by Momentive Co., Ltd.) and 1 cc of aqueous ammonia are added to 180 g of IPA (manufactured by Kanto Chemical Co., Ltd., reagent special grade) and mixed for 2 hours with stirring to contain a mercapto group. A coating material of silane organometallic hydrolysis condensate was obtained.

  This mercapto group-containing silane organometallic hydrolyzed condensate is added to and mixed in total 200 g of IPA (Kanto Chemical Co., Ltd., reagent grade), and then 200 g of sulfide phosphor particles are added, and an ultrasonic vibration of 28 kHz is applied. The treatment for 5 minutes was performed 3 times to disperse. After this dispersion was stirred and mixed at 23 ° C. for 1 hour, the dispersion was vacuum filtered to collect phosphor particles adsorbed with a mercapto group-containing silane organometallic hydrolysis condensate.

  The resulting sulfide phosphor particles adsorbed with the mercapto group-containing silane organometallic hydrolysis condensate are heat-treated in the atmosphere at a temperature of 250 ° C. for 1 hour, whereby a coating film of amorphous inorganic oxide is obtained. A sulfide-coated phosphor particle with a coating film was prepared.

  The obtained sulfide phosphor particles with a coating film having a coating film of an amorphous inorganic oxide were kneaded into a silicone resin (ASP-1020, manufactured by Shin-Etsu Chemical Co., Ltd.) in the same manner as in Example 1 above. 1 g each of the kneaded resin was weighed and cast into 10 glass molds. Each obtained cast material was cured under the conditions of 250 ° C. × 2 hours to prepare a cured silicone resin containing sulfide phosphor particles with a coating film.

  The obtained coated phosphor-coated sulfide phosphor particles of Comparative Example 1 were evaluated in the same manner as in Example 1, and the results are shown in Table 1 below.

[Comparative Example 2]
To 1000 g of methyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd., Z-6366), 680 g of ethanol (manufactured by Kanto Chemical Co., Ltd., special grade reagent), 6 cc of ammonia water, and 320 g of ion-exchanged water were added. The mixture was vigorously stirred with a stirrer for 2 hours while maintaining a temperature of 0 ° C. to obtain a coating material for an organic solution containing a silane organometallic hydrolysis condensate.

  100 g of sulfide phosphor particles were mixed with 350 g of the obtained coating material, and dispersed by applying 48 kHz ultrasonic vibration for 5 minutes. The dispersion is stirred and mixed at 23 ° C. for 1 hour, the re-dispersion is vacuum filtered, heated and dried at a temperature of 110 ° C. for 1 hour, and further heat-treated at 250 ° C. for 1 hour in the atmosphere to produce an amorphous material. Coated sulfide phosphor particles having a porous inorganic oxide coating film were prepared.

  The obtained sulfide phosphor particles with a coating film having a coating film of an amorphous inorganic oxide were kneaded into a silicone resin (ASP-1020, manufactured by Shin-Etsu Chemical Co., Ltd.) in the same manner as in Example 1 above. 1 g each of the kneaded resin was weighed and cast into 10 glass molds. Each obtained cast material was cured under the conditions of 250 ° C. × 2 hours to prepare a cured silicone resin containing sulfide phosphor particles with a coating film.

  The obtained coated phosphor-coated sulfide phosphor particles of Comparative Example 2 were evaluated in the same manner as in Example 1, and the results are shown in Table 1 below.

[Comparative Example 3]
By adding 200 g of 3-mercaptopropyltrimethoxysilane (A189, manufactured by Momentive Co., Ltd.) and 1 cc of aqueous ammonia to 180 g of IPA (manufactured by Kanto Chemical Co., Ltd., reagent special grade) and continuing stirring and mixing for 2 hours A mercapto group-containing silane organometallic hydrolysis condensate was obtained.

The total amount of the resulting mercapto group-containing silane organometallic hydrolysis condensate was added to and mixed with 200 g of IPA (manufactured by Kanto Chemical Co., Ltd., reagent special grade). In this solution, 200 g of SrGa ₂ S ₄ : Eu particles (average particle diameter D50 = 5.6 μm) was added, and a treatment of applying 28 kHz ultrasonic vibration for 5 minutes was performed three times to be dispersed. This dispersion was stirred and mixed at 23 ° C. for 1 hour and then vacuum filtered to recover sulfide phosphor particles adsorbed with a mercapto group-containing silane organometallic hydrolysis condensate as an underlayer.

  Separately, 680 g of ethanol (manufactured by Kanto Chemical Co., Ltd., reagent grade), 6 cc of ammonia water, and 320 g of ion-exchanged water were added to 1000 g of methyltrimethoxysilane (manufactured by Toray Dow Corning Co., Ltd., Z-6366). While stirring at a temperature of 23 ° C., the mixture was vigorously stirred with a stirrer. This stirring and mixing was continued for 2 hours to obtain a coating material of a silane organometallic hydrolysis condensate.

  This coating material 350g was mixed with 100g of sulfide phosphor particles adsorbed with the mercapto group-containing silane organometallic hydrolysis condensate as described above, and dispersed by applying 48kHz ultrasonic vibration for 5 minutes. And stirred for 1 hour. The dispersion is vacuum filtered, heat-dried at a temperature of 110 ° C. for 1 hour, and then heat-treated in the atmosphere at a temperature of 250 ° C. for 1 hour to provide a coating film having an amorphous inorganic oxide coating film Sulfide phosphor particles were prepared.

  The obtained sulfide phosphor particles with a coating film having a coating film of an amorphous inorganic oxide were kneaded into a silicone resin (ASP-1020, manufactured by Shin-Etsu Chemical Co., Ltd.) in the same manner as in Example 1 above. 1 g each of the kneaded resin was weighed and cast into 10 glass molds. Each obtained cast material was cured under the conditions of 250 ° C. × 2 hours to prepare a cured silicone resin containing sulfide phosphor particles with a coating film.

  The obtained sulfide phosphor particles with a coating film of Comparative Example 3 were evaluated in the same manner as in Example 1, and the results are shown in Table 1 below.

[Comparative Example 4]
In the same manner as in Example 1, sulfide phosphor particles with a coating film were obtained. 10 g of the obtained sulfide phosphor particles with a coating film and 90 g of a silicone resin (manufactured by Toray Dow Corning Co., Ltd., JCR6122) were kneaded with a mixer for 3 minutes. The silicone resin JCR6122 has an oxygen permeability of 20,000 cm ³ · cm / m ² · 24 hr · atm, and a tensile strength of 0.8 MPa.

  The obtained kneaded resin was weighed in units of 1 g and cast into 10 glass molds. Each obtained cast material was cured under the conditions of 150 ° C. × 2 hours to prepare a cured silicone resin containing sulfide phosphor particles with a coating film.

  The obtained sulfide phosphor particles with a coating film of Comparative Example 4 were evaluated in the same manner as in Example 1, and the results are shown in Table 1 below.

[Comparative Example 5]
In the same manner as in Example 1, sulfide phosphor particles with a coating film were obtained. 10 g of the obtained sulfide phosphor particles with a coating film and 90 g of silicone resin (manufactured by Toray Dow Corning Co., Ltd., JCR6175) were kneaded with a mixer for 3 minutes. The oxygen permeability of the silicone resin JCR6175 is 1,000 cm ³ · cm / m ² · 24 hr · atm, and the tensile strength is 0.3 MPa.

  The obtained kneaded resin was weighed in units of 1 g and cast into 10 glass molds. Each obtained cast material was cured under the conditions of 150 ° C. × 2 hours to prepare a cured silicone resin containing sulfide phosphor particles with a coating film.

  The obtained sulfide phosphor particles with a coating film of Comparative Example 5 were evaluated in the same manner as in Example 1, and the results are shown in Table 1 below.

[Comparative Example 6]
In the same manner as in Example 1, sulfide phosphor particles with a coating film were obtained. 100 g of the obtained sulfide phosphor particles with a coating film and 90 g of a silicone resin (manufactured by Toray Dow Corning Co., Ltd., OE6630) were kneaded with a mixer for 3 minutes. The silicone resin OE6630 has an oxygen permeability of 800 cm ³ · cm / m ² · 24 hr · atm, and a tensile strength of 0.7 MPa.

  The obtained kneaded resin was weighed in units of 1 g and cast into 10 glass molds. Each cast material was cured under conditions of 150 ° C. × 2 hours to prepare a cured silicone resin containing sulfide phosphor particles with a coating film.

The obtained sulfide phosphor particles with a coating film of Comparative Example 6 were evaluated in the same manner as in Example 1, and the results are shown in Table 1 below.
Table 1 below also shows the types of silicone resins used in each of the above Examples and Comparative Examples, and the blending ratio (resin: particles) of the silicone resin and sulfide phosphor particles with a coating film. .

  As can be seen from the results in Table 1 above, in Examples 1 to 5 according to the present invention, good results were obtained for all the evaluation items. In particular, a dense, uniform and defect-free coating film can be formed on the surface of the sulfide phosphor particles, and the emission intensity of the sulfide phosphor particles slightly increases after the coating film is formed. And it turns out that the sulfide fluorescent substance particle with a coating film and its sulfide fluorescent substance containing silicone resin hardening body have the outstanding water resistance, and are excellent for LED light emitting devices.

  On the other hand, in Comparative Examples 1 to 6 that are not treated according to the conditions of the first step to the fourth step of the present invention, the adhesion of the coating film may be poor or the light emission characteristics before and after the coating may be deteriorated. It is recognized that the moisture resistance test by the change in water resistance and the evaluation of the moisture resistance and water resistance of the phosphor particle-containing resin cured body by the silver plate reflectance are clearly inferior to the examples of the present invention.

Claims (7)

A silicone resin blend of a curing catalyst is cured containing mixture with a fatty acid group having 2 liquid type thermosetting silicone resin, contained therein, Si derived from the organic metal hydrolytic condensate, Al, and O a cured product of the silicone resin whose surface a two-layer coating film of amorphous inorganic oxide as a main component containing a coated coating film with sulfide phosphor particles,
The cured oxygen permeability of the silicone resin is ^{600cm 3 · cm / m 2 ·} 24hr · atm and below the tensile strength is 1MPa～10MPa, coating of two layers coated on the sulfide phosphor particle surface a first layer of the coating film is amorphous inorganic oxide from the mercapto group-containing silane organometallic hydrolytic condensate of weight-average molecular weight of 1,000 to 10,000 of the film, the sulfide the second layer of the coating film weight average molecular weight 5,000 to 20,000 of uniform silane organometallic hydrolytic condensate from a non-of of the coating film of two layers coated on the surfaces of phosphor particles A cured cured silicone resin containing sulfide phosphor particles with a coating film , which is a crystalline inorganic oxide . 2. The coating film according to claim 1, wherein a film thickness of the two-layer coating film of the amorphous inorganic oxide mainly containing Si, Al, and O is 50 to 200 nm. A cured silicone resin containing sulfide phosphor particles. The manufacturing method of the silicone resin hardening body containing a sulfide fluorescent substance particle with a coating film characterized by including each process of following (1)-(4).
(1) Coating a mercapto group-containing silane organometallic compound having a weight average molecular weight of 1,000 to 10,000 by hydrolyzing a mercapto group-containing silane organometallic compound with an aluminum organometallic compound as a catalyst, an organic solvent and water. A first step of preparing a first coating film on the surface of the sulfide phosphor particles by preparing a material and stirring and mixing the coating material and the sulfide phosphor particles in a container;
(2) A silane organometallic compound is hydrolyzed with an aluminum organometallic compound as a catalyst, an organic solvent and water to prepare a coating material for a silane organometallic hydrolyzed condensate having a weight average molecular weight of 5,000 to 20,000. Uniform coating of the second layer on the surface of the sulfide phosphor particles by stirring and mixing the coating material and the sulfide phosphor particles having the coating film of the first layer obtained in the first step in a container Second step of forming a film.
(3) The sulfide phosphor particles having the first layer and the second layer coating film obtained in the second step are heat-treated in the atmosphere, and Si, Al, A third step of obtaining sulfide phosphor particles with a coating film having a coating film of an amorphous inorganic oxide mainly containing O.
(4) The sulfide phosphor particles with a coating film obtained in the third step are blended with a curing catalyst containing a fatty acid group in a mixture of two-component thermosetting silicone resin , and the oxygen permeability after curing There ^{600cm 3 · cm / m 2 ·} 24hr · atm or less and a tensile strength kneading was admixed with the thermosetting silicone resin of 1MPa～10MPa, by heat curing at 110 to 150 ° C. in air, the A fourth step of obtaining a cured silicone resin-containing sulfide phosphor particle-containing film.   The mercapto group-containing silane organometallic compound in the first step is at least one selected from 3-mercaptopropyltrimethoxysilane and 3-mercaptopropyltriethoxysilane. A method for producing a cured cured silicone resin containing sulfide phosphor particles with a coating film.   The silane organometallic compound in the second step is at least one selected from methyltriethoxysilane, methyltrimethoxysilane, ethyltrimethoxysilane, ethyltriethoxysilane, and n-propyltrimethoxysilane. The manufacturing method of the cured silicone resin containing sulfide phosphor particles with a coating film according to claim 3 or 4.   The aluminum organometallic compound in the first step and the second step is ethyl acetoacetate aluminum diisopropylate, aluminum tris (ethyl acetoacetate), octyl acetoacetate aluminum diisopropylate, aluminum monoacetylacetonate bis (ethyl acetoacetate) The method for producing a cured silicone resin-containing sulfide phosphor particle with a coating film according to any one of claims 3 to 5, which is at least one selected from the group consisting of:   The viscosity of the thermosetting silicone resin when adding and mixing the sulfide phosphor particles with a coating film in the fourth step is 400 to 5,000 mPa · s. The manufacturing method of the sulfide fluorescent substance particle containing silicone resin hardening body with a coating film in any one of these.