JP3801261B2 - Ba-Eu coprecipitated carbonate fine powder for blue phosphor material for three-wavelength fluorescent lamp and method for producing the same - Google Patents
Ba-Eu coprecipitated carbonate fine powder for blue phosphor material for three-wavelength fluorescent lamp and method for producing the same Download PDFInfo
- Publication number
- JP3801261B2 JP3801261B2 JP14260996A JP14260996A JP3801261B2 JP 3801261 B2 JP3801261 B2 JP 3801261B2 JP 14260996 A JP14260996 A JP 14260996A JP 14260996 A JP14260996 A JP 14260996A JP 3801261 B2 JP3801261 B2 JP 3801261B2
- Authority
- JP
- Japan
- Prior art keywords
- ions
- liquid
- carbonate
- fine powder
- fluorescent lamp
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
Landscapes
- Compounds Of Alkaline-Earth Elements, Aluminum Or Rare-Earth Metals (AREA)
Description
【０００１】
【発明の属する技術分野】
本発明は、３波長型蛍光灯用の青色蛍光体の原料として有用なＢa-Ｅu 共沈炭酸塩微粉およびその製造方法に関するものである。
【０００２】
【従来の技術】
３波長型蛍光灯の青色蛍光体の原料としては、Ｅu2+ 付活のアルミン酸塩が知られており、その組成の一例としてＢa Ｍg2Ａl16 Ｏ27：Ｅu2+ を挙げることができる。ここで、Ｅu2+ はＢa のサイトに置換されていることが確認されている。
Ｂa Ｍg2Ａl16 Ｏ27：Ｅu2+ 蛍光体の製造方法は、蛍光体ハンドブック（蛍光体同学会編、オーム社、p.226 ）によれば、「原料としてＢa ＣＯ3 、Ｂa(ＮＯ3)2 やＭg4( ＣＯ3)3 ＯＨ・３Ｈ2 Ｏなどのアルカリ土類金属炭酸塩、α−Ａl2Ｏ3 、Ｅu2Ｏ3 と適量のフラックスを用いて、これらをボールミルなどで混合し、1200℃で２時間弱還元性気流中（２％Ｈ2/Ｎ2 ）で焼成し、同気流中で冷却し、これを粉砕、篩分け後、1200℃で２時間弱還元性気流中で再度焼成することによって目的とする蛍光体を得る。」と記載されている。
しかしながら、このような粉体混合法では各原料を均一に混合することは非常に困難なために、局部的な不均一状態が生じ易く、最終的に得られる蛍光体の個々の粒子間の組成にバラツキをもたらし、特にＥu2+ の組成のバラツキは蛍光体の特性に悪影響を及ぼすことになる。
【０００３】
【発明が解決しようとする課題】
本発明は、上記の問題点に鑑み、発光成分であるＥu2+ の組成の均一性を高めることを目的としながら、かつＥu2+ 付活のアルミン酸塩青色蛍光体の原料に適した粒径を有するＢa-Ｅu 共沈炭酸塩とその製造方法を提供しようとするものである。
【０００４】
【課題を解決するための手段】
本発明者は、上記課題を解決するために、ＢａとＥｕの共沈条件を種々検討し本発明を完成したもので、その要旨は、
平均粒径が１μｍ以上５μｍ以下であることを特徴とするＢａ−Ｅｕ共沈炭酸塩微粉、およびＢａイオンとＥｕイオンを含む水溶液（Ａ液とする）と炭酸イオンを含む水溶液（Ｂ液とする）を混合してＢａ−Ｅｕ共沈炭酸塩を析出するに際し、Ａ液に対してＢ液を投入する場合、Ｂ液に対してＡ液を投入する場合、或はＡ液とＢ液を同時に投入する場合のいずれにおいても、投入時間を５秒以上５分以下とすることを特徴とし、かつＢａイオンとＥｕイオンに対する炭酸イオンの比率が、Ｂａイオンの全てをＢａＣＯ 3 として、およびＥｕイオンの全てをＥｕＣＯ 3 として沈澱させるのに必要な化学量論比の１．０〜１．１倍である３波長型蛍光灯用の青色蛍光体の原料用Ｂａ−Ｅｕ共沈炭酸塩微粉およびその製造方法である。
【０００５】
【発明の実施の形態】
以下、本発明を詳細に説明する。
Ｂa-Ｅu 共沈炭酸塩はＢa イオンとＥu イオンを含む水溶液（Ａ液とする）と炭酸イオンを含む水溶液（Ｂ液とする）を混合することにより沈澱生成する。その混合方法には、Ａ液に対してＢ液を投入する方法、Ｂ液にＡ液を投入する方法、Ａ液とＢ液を同時に投入する方法があるが、Ｂa-Ｅu 共沈炭酸塩の粒径に影響する主要因は液の投入時間であり、投入時間を制御すれば混合方法は前記３種のいずれでもよい。
液の投入時間を短くすれば粒径は小さく、長くすれば粒成長により粒径は大きくなるが、本発明の目的である平均粒径１μm 以上５μm 以下のＢa-Ｅu 共沈炭酸塩粒子を製造するためには、液の投入時間は５秒以上５分以内であることが必要である。５秒未満（以下は５秒も含む）では１次粒子が小さくなって凝集が起こり、５分を超えると粒子の成長により平均粒径が大きくなる。
【０００６】
液の投入時間に次いで重要な因子はＢa イオンとＥu イオンに対する炭酸イオンの比率である。Ｂa イオンとＥu イオンに対する炭酸イオンの比率は、Ｂa イオンとＥu イオンの全てを炭酸塩として沈澱させるのに必要な化学量論比の1.0 〜1.1 倍であることが必要である。ここで、Ｂa イオンとＥu イオンに対する炭酸イオンの化学量論比とは、Ｂa イオンはＢa ＣＯ3 として、Ｅu イオンはＥu 2(ＣＯ3)3 として沈澱するとして計算したＡ液中のＢa イオンとＥu イオンに対するＢ液中の炭酸イオンのモル比をいう。比率が1.0 未満ではＢa-Ｅu 共沈炭酸塩の収率が低下し、1.1 を超えるとＢa の再溶解が起こり収率が低下する。
【０００７】
液中Ｂa 、Ｅu および炭酸イオン濃度は、粒径および収率に対して支配的な因子ではないが、生産性の観点から0.05mol/L 以上が好ましい。上限については特に制限はなく、飽和濃度でも実施可能である。
温度についても特に制限はなく、加熱や冷却のためのエネルギーを要しない室温で行うのが最も経済的であるが、Ｂa 塩として硝酸バリウムを使用したときには溶解度を上げるために、50〜80℃程度に加熱した方が生産性が上がり有利となる。
【０００８】
Ｂa イオンとＥu イオンを含む水溶液と炭酸イオンを含む水溶液を混合して得られた沈澱物であるＢa ＣＯ3-Ｅu2( ＣＯ3)3 は公知の方法で濾過、洗浄、乾燥して乾燥粉末として蛍光体製造工程に供給される。
【０００９】
【実施例】
以下、本発明の実施形態を実施例と比較例を挙げて具体的に説明するが、本発明はこれらに何等限定されるものではない。
（実施例１）
30L のジャケット付きステンレス製反応容器に、0.291mol/Lの炭酸アンモニウム水溶液10L を張り込み50℃に加温した。この溶液に予め50℃に加温した0.25mol/L の硝酸バリウムと0.0268mol/L の硝酸ユウロピウムの混合水溶液10L を３分間で投入した。この時のＢa イオンとＥu イオンに対する炭酸イオンの化学量論比は1.0 であった。
次に、ブッフナー漏斗で沈澱物を濾別し、脱イオン水で洗浄した。さらに、該沈澱物を80℃で16時間乾燥し、531gのＢa-Ｅu 共沈炭酸塩を得た。この時の収率は96％であった。
マイクロトラック社のレーザー回折法による粒度分布測定装置（型番SPA ）で測定した平均粒径は3.76μm であった。
組成の均一性については、ＥＰＭＡ（電子線マイクロアナライザー）を使用してＢa とＥu の特性をＸ線の面分析により確認した。共沈炭酸塩を金型プレスでペレットにして分析試料とした。分析の結果、Ｂa およびＥu の偏析は観察されず、両元素が均一に分布していることが判った。
【００１０】
（実施例２）
30L のジャケット付きステンレス製反応容器に、0.25mol/L の硝酸バリウムと0.0268mol/L の硝酸ユウロピウムの混合水溶液10L を張り込み50℃に加温した。この溶液に、予め50℃に加温した0.291mol/Lの炭酸アンモニウム水溶液10L を３分間で投入した。この時のＢa イオンとＥu イオンに対する炭酸イオンの化学量論比は1.0 であった。
次に、ブッフナー漏斗で沈澱物を濾別し、脱イオン水で洗浄した。さらに、該沈澱物を80℃で16時間乾燥し、534gのＢa-Ｅu 共沈炭酸塩を得た。この時の収率は96％であり、平均粒径は3.24μm であった。
ＥＰＭＡによる面分析の結果、Ｂa およびＥu の偏析は観察されず、両元素が均一に分布していることが判った。
【００１１】
（実施例３）
30L のジャケット付きステンレス製反応容器に、８L の脱イオン水を張り込み、50℃に加温した。この温水に、予め50℃に加温した0.25mol/L の硝酸バリウムと0.0268mol/L の硝酸ユウロピウムの混合水溶液10L と、同じく予め50℃に加温した0.291mol/Lの炭酸アンモニウム水溶液10L とを３分間で同時に投入した。この時のＢa イオンとＥu イオンに対する炭酸イオンの化学量論比は1.0 であった。
次に、ブッフナー漏斗で沈澱物を濾別し、脱イオン水で洗浄した。さらに、該沈澱物を80℃で16時間乾燥し、533gのＢa-Ｅu 共沈炭酸塩を得た。この時の収率は96％であり、平均粒径は3.15μm であった。
ＥＰＭＡによる面分析の結果、Ｂa およびＥu の偏析は観察されず、両元素が均一に分布していることが判った。
【００１２】
（比較例１）
硝酸バリウムと硝酸ユウロピウムの混合溶液の投入時間を10分間としたこと以外は実施例１と同様の方法で531gのＢa-Ｅu 共沈炭酸塩を得た。この時の収率は95％であり、平均粒径は6.31μm であった。
【００１３】
（比較例２）
硝酸バリウムと硝酸ユウロピウムの混合溶液の投入時間を３秒間としたこと以外は実施例１と同様の方法で533gのＢa-Ｅu 共沈炭酸塩を得た。この時の収率は95％であった。乾燥物は固く凝集していたので平均粒径の測定は行わなかった。
【００１４】
（比較例３）
予め反応容器に張り込んでおく炭酸アンモニウムの濃度を0.35mol/L （即ち、Ｂa イオンとＥu イオンに対する炭酸イオンの化学量論比を1.2 とした）としたこと以外は実施例１と同様の方法で484gのＢa-Ｅu 共沈炭酸塩を得た。この時の収率は87％であった。平均粒径は4.02μm と目標範囲内であったが、収率が悪く、工業的実現性に乏しい。
【００１５】
【発明の効果】
本発明によれば、３波長型蛍光灯用の青色蛍光体の原料として有用な平均粒径が１μm 以上５μm 以下のＢa-Ｅu 共沈炭酸塩微粉が高収率で製造でき、産業上その利用価値は極めて高い。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a Ba-Eu coprecipitated carbonate fine powder useful as a raw material for a blue phosphor for a three-wavelength fluorescent lamp and a method for producing the same.
[0002]
[Prior art]
Eu 2+ -activated aluminate is known as a raw material for the blue phosphor of the three-wavelength fluorescent lamp, and Ba Mg 2 Al 16 O 27 : Eu 2+ can be cited as an example of the composition. . Here, it has been confirmed that Eu 2+ is substituted at the site of Ba.
The production method of Ba Mg 2 Al 16 O 27 : Eu 2+ phosphor is described as “Ba CO 3 as a raw material, Ba (NO 3 ) 2 and Mg 4 (CO 3 ) 3 OH 3H 2 O and other alkaline earth metal carbonates, α-Al 2 O 3 , Eu 2 O 3 and a suitable amount of flux are mixed in a ball mill or the like. Baked in a slightly reducing airflow (2% H 2 / N 2 ) at 1200 ° C for 2 hours, cooled in the same airflow, crushed and sieved, and then in 1200 ° C for 2 hours in a slightly reducing airflow The target phosphor is obtained by firing again. "
However, since it is very difficult to uniformly mix the raw materials in such a powder mixing method, a local non-uniform state is likely to occur, and the composition between the individual particles of the finally obtained phosphor In particular, the variation in the composition of Eu 2+ will adversely affect the characteristics of the phosphor.
[0003]
[Problems to be solved by the invention]
In view of the above problems, the present invention aims to improve the uniformity of the composition of Eu 2+ , which is a luminescent component, and is suitable for a raw material of Eu 2+ activated aluminate blue phosphor. It is an object of the present invention to provide a Ba-Eu coprecipitated carbonate having a diameter and a method for producing the same.
[0004]
[Means for Solving the Problems]
In order to solve the above problems, the present inventor has studied the coprecipitation conditions of Ba and Eu in various ways, and has completed the present invention.
Ba-Eu coprecipitated carbonate fine powder having an average particle size of 1 μm or more and 5 μm or less, an aqueous solution containing Ba ions and Eu ions (referred to as liquid A), and an aqueous solution including carbonate ions (referred to as liquid B) ) To precipitate Ba-Eu coprecipitated carbonate, when B liquid is added to A liquid, A liquid is added to B liquid, or A liquid and B liquid are simultaneously mixed. in any of the cases to be introduced also characterized by the on time more than 5 minutes or 5 seconds, and the proportion of carbonate ions relative to Ba and Eu ions, all Ba ions as BaCO 3, and Eu Io feedstock Ba -Eu co沈炭salt of the blue phosphor of the three band fluorescent lamp Ru 1.0 to 1.1 Baidea stoichiometry required to precipitation lees all as EuCO 3 of emissions a fine powder and a manufacturing method thereof.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in detail.
Ba-Eu coprecipitated carbonate is precipitated by mixing an aqueous solution containing Ba ions and Eu ions (referred to as solution A) and an aqueous solution containing carbonate ions (referred to as solution B). The mixing method includes a method in which the B solution is added to the A solution, a method in which the A solution is introduced into the B solution, and a method in which the A solution and the B solution are added simultaneously. The main factor that influences the particle size is the liquid charging time, and the mixing method may be any of the above three methods as long as the charging time is controlled.
The particle size is reduced if the liquid charging time is shortened, and the particle size is increased by grain growth if it is lengthened. However, Ba-Eu coprecipitated carbonate particles having an average particle diameter of 1 μm to 5 μm, which is the object of the present invention, are produced. In order to achieve this, it is necessary that the charging time of the liquid is 5 seconds or more and 5 minutes or less. If it is less than 5 seconds (including 5 seconds below), the primary particles become small and agglomerate, and if it exceeds 5 minutes, the average particle size increases due to particle growth.
[0006]
The next most important factor after the charging time is the ratio of carbonate ions to Ba ions and Eu ions. The ratio of carbonate ions to Ba ions and Eu ions should be 1.0 to 1.1 times the stoichiometric ratio required to precipitate all of the Ba ions and Eu ions as carbonates. Here, the stoichiometric ratio of carbonate ions to Ba ions and Eu ions is calculated as follows: Ba ions calculated as Ba CO 3 and Eu ions precipitated as Eu 2 (CO 3 ) 3. This refers to the molar ratio of carbonate ions in solution B to Eu ions. If the ratio is less than 1.0, the yield of Ba-Eu coprecipitated carbonate decreases, and if it exceeds 1.1, Ba re-dissolves and the yield decreases.
[0007]
The concentration of Ba, Eu and carbonate ions in the liquid is not a dominant factor for the particle size and yield, but is preferably 0.05 mol / L or more from the viewpoint of productivity. The upper limit is not particularly limited, and can be carried out even at a saturated concentration.
There is no particular restriction on the temperature, and it is most economical to carry out at room temperature that does not require energy for heating and cooling. However, when barium nitrate is used as the Ba salt, it is about 50 to 80 ° C. in order to increase the solubility. Heating is more advantageous because it increases productivity.
[0008]
Ba CO 3 -Eu 2 (CO 3 ) 3 , which is a precipitate obtained by mixing an aqueous solution containing Ba ions and Eu ions and an aqueous solution containing carbonate ions, is filtered, washed and dried by a known method to obtain a dry powder. Is supplied to the phosphor manufacturing process.
[0009]
【Example】
Hereinafter, although an embodiment and a comparative example are given and an embodiment of the present invention is explained concretely, the present invention is not limited to these at all.
Example 1
A 30 L jacketed stainless steel reaction vessel was charged with 10 L of 0.291 mol / L ammonium carbonate aqueous solution and heated to 50 ° C. To this solution, 10 L of a mixed aqueous solution of 0.25 mol / L barium nitrate and 0.0268 mol / L europium nitrate previously heated to 50 ° C. was added in 3 minutes. At this time, the stoichiometric ratio of carbonate ions to Ba ions and Eu ions was 1.0.
The precipitate was then filtered off with a Buchner funnel and washed with deionized water. Further, the precipitate was dried at 80 ° C. for 16 hours to obtain 531 g of Ba-Eu coprecipitated carbonate. The yield at this time was 96%.
The average particle diameter measured by a particle size distribution measuring apparatus (model number SPA) by Microtrac's laser diffraction method was 3.76 μm.
Regarding the uniformity of composition, the characteristics of Ba and Eu were confirmed by X-ray surface analysis using EPMA (electron beam microanalyzer). The coprecipitated carbonate was pelleted with a mold press to prepare an analytical sample. As a result of analysis, no segregation of Ba and Eu was observed, and it was found that both elements were uniformly distributed.
[0010]
(Example 2)
A 30 L jacketed stainless steel reaction vessel was charged with 10 L of a mixed aqueous solution of 0.25 mol / L barium nitrate and 0.0268 mol / L europium nitrate and heated to 50 ° C. To this solution, 10 L of a 0.291 mol / L aqueous ammonium carbonate solution preheated to 50 ° C. was added in 3 minutes. At this time, the stoichiometric ratio of carbonate ions to Ba ions and Eu ions was 1.0.
The precipitate was then filtered off with a Buchner funnel and washed with deionized water. Further, the precipitate was dried at 80 ° C. for 16 hours to obtain 534 g of Ba-Eu coprecipitated carbonate. The yield at this time was 96%, and the average particle size was 3.24 μm.
As a result of surface analysis by EPMA, no segregation of Ba and Eu was observed, and it was found that both elements were uniformly distributed.
[0011]
Example 3
A 30 L jacketed stainless steel reaction vessel was filled with 8 L deionized water and heated to 50 ° C. To this warm water, 10 L of a mixed aqueous solution of 0.25 mol / L barium nitrate and 0.0268 mol / L europium nitrate previously heated to 50 ° C., and 10 L of a 0.291 mol / L ammonium carbonate aqueous solution previously heated to 50 ° C. Were simultaneously added in 3 minutes. At this time, the stoichiometric ratio of carbonate ions to Ba ions and Eu ions was 1.0.
The precipitate was then filtered off with a Buchner funnel and washed with deionized water. Further, the precipitate was dried at 80 ° C. for 16 hours to obtain 533 g of Ba-Eu coprecipitated carbonate. The yield at this time was 96%, and the average particle size was 3.15 μm.
As a result of surface analysis by EPMA, no segregation of Ba and Eu was observed, and it was found that both elements were uniformly distributed.
[0012]
(Comparative Example 1)
531 g of Ba-Eu coprecipitated carbonate was obtained in the same manner as in Example 1 except that the charging time of the mixed solution of barium nitrate and europium nitrate was 10 minutes. The yield at this time was 95%, and the average particle size was 6.31 μm.
[0013]
(Comparative Example 2)
533 g of Ba-Eu coprecipitated carbonate was obtained in the same manner as in Example 1 except that the charging time of the mixed solution of barium nitrate and europium nitrate was 3 seconds. The yield at this time was 95%. Since the dried product was hard agglomerated, the average particle size was not measured.
[0014]
(Comparative Example 3)
The same method as in Example 1 except that the concentration of ammonium carbonate previously placed in the reaction vessel was 0.35 mol / L (that is, the stoichiometric ratio of carbonate ion to Ba ion and Eu ion was 1.2). Yielded 484 g of Ba-Eu coprecipitated carbonate. The yield at this time was 87%. The average particle size was 4.02 μm, which was within the target range, but the yield was poor and industrial feasibility was poor.
[0015]
【The invention's effect】
According to the present invention, Ba-Eu coprecipitated carbonate fine powder having an average particle diameter of 1 μm or more and 5 μm or less that is useful as a raw material for a blue phosphor for a three-wavelength fluorescent lamp can be produced in high yield, and its industrial use. The value is extremely high.
Claims (3)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14260996A JP3801261B2 (en) | 1996-06-05 | 1996-06-05 | Ba-Eu coprecipitated carbonate fine powder for blue phosphor material for three-wavelength fluorescent lamp and method for producing the same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP14260996A JP3801261B2 (en) | 1996-06-05 | 1996-06-05 | Ba-Eu coprecipitated carbonate fine powder for blue phosphor material for three-wavelength fluorescent lamp and method for producing the same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH09328314A JPH09328314A (en) | 1997-12-22 |
| JP3801261B2 true JP3801261B2 (en) | 2006-07-26 |
Family
ID=15319315
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP14260996A Expired - Fee Related JP3801261B2 (en) | 1996-06-05 | 1996-06-05 | Ba-Eu coprecipitated carbonate fine powder for blue phosphor material for three-wavelength fluorescent lamp and method for producing the same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3801261B2 (en) |
-
1996
- 1996-06-05 JP JP14260996A patent/JP3801261B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPH09328314A (en) | 1997-12-22 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JP4018974B2 (en) | Tin oxide powder, method for producing the same, and method for producing high-density indium tin oxide target using the same | |
| JPH08277118A (en) | Preparation of lithium interlayer compound | |
| JPH07315816A (en) | Rare earth element salt particle of phosphoric acid and its production | |
| US20030178752A1 (en) | Indium oxide powder, method for preparing the same, and method for manufacturing high-density indium tin oxide target | |
| JPH06510272A (en) | Improved mixed metal oxide crystal powder and its synthesis method | |
| WO2002044303A1 (en) | Process for producing fluorescent metal oxide material | |
| CN109082272A (en) | A kind of red light fluorescent powder and preparation method thereof | |
| EP0068117A1 (en) | Zinc silicate phosphors and methods for making them | |
| JP2003500516A (en) | Method for preparing coated phosphor particles, phosphor prepared by the method, and plastic material incorporating the same | |
| WO2012127771A1 (en) | Process for producing sintered magnesium oxide material | |
| JP3801261B2 (en) | Ba-Eu coprecipitated carbonate fine powder for blue phosphor material for three-wavelength fluorescent lamp and method for producing the same | |
| JP2843909B2 (en) | Method for producing yttrium oxide transparent sintered body | |
| CN106433641B (en) | A kind of method that low heat temperature solid state reaction prepares rear-earth-doped calcium stannate fluorescent material | |
| JP2000080363A (en) | Preparation of green light-emitting phosphor | |
| JP2005179399A (en) | Manufacturing method of aluminate salt fine particle light-accumulating powder | |
| JPWO2013051576A1 (en) | Conductive mayenite compound sintered body, sputtering target, and method for producing conductive mayenite compound sintered body | |
| JPS5913625A (en) | Manufacture of oxysulfide of rare earth element | |
| JP2002321921A (en) | Method for manufacturing lithium cobalt oxide | |
| JP3320762B2 (en) | Method for producing blue pigment and blue light-emitting phosphor with pigment | |
| KR100420276B1 (en) | Preparation of ZnO Powder by Pyrophoric Synthesis Method | |
| JPS62191423A (en) | Production of easily sintering lead-containing oxide powder | |
| KR100425382B1 (en) | Method of low temperature synthesis of Zn2SiO4 powder having a narrow size-distribution via hydrothermal technique | |
| JPH09255950A (en) | Preparation of light-storing luminescent pigment | |
| CA1096158A (en) | Yitrium indium phosphate x-ray phosphors | |
| JPH1179742A (en) | Production of yttria/gadolinia/europia coprecipitated single-dispersed spherical particles and yttria/gadolinia/ europia coprecipitated single-dispersed spherical particles obtained by same |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20050502 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20060118 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20060314 |
|
| TRDD | Decision of grant or rejection written | ||
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20060424 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20060425 |
|
| R150 | Certificate of patent or registration of utility model |
Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20120512 Year of fee payment: 6 |
|
| LAPS | Cancellation because of no payment of annual fees |