JP3988615B2 - Plasma display device - Google Patents

Description

【０１００】
サンプル１〜４は、赤色蛍光体に（Ｙ，Ｇｄ）_1-xＢＯ₃：Ｅｕ_x、緑色蛍光体に（Ｚｎ_2-xＳｉＯ₄：Ｍｎ_x）、青色蛍光体に〔Ｍｅ_1-xＭｇＳｉ₂Ｏ₆：Ｅｕ_x（Ｍｅは、Ｃａ，Ｓｒ，Ｂａの組み合わせ）〕を用いた組み合わせのものであり、蛍光体の製造方法および発光中心となるＥｕ，Ｍｎの置換比率、すなわちＹ，Ｍｅ元素に対するＥｕの置換比率、およびＺｎ元素に対するＭｎの置換比率及びＭｅの組み合わせを表１のように変化させたものである。
【０１０１】
サンプル５〜９は、赤色蛍光体に（Ｙ_2-xＯ₃：Ｅｕ_x）、緑色蛍光体に（Ｂａ_1-xＡｌ₁₂Ｏ₁₉：Ｍｎ_x）、青色蛍光体に〔Ｍｅ_1-xＭｇＳｉ₂Ｏ₆：Ｅｕ_x（Ｍｅは、Ｃａ，Ｓｒ，Ｂａの組み合わせ）〕を用いた組み合わせのものであり、上記と同様、水熱合成方法、噴霧合成方法、加水分解方法でそれぞれの蛍光体を作製した。また、発光中心の置換比率及びＭｅの組み合わせを表１のように変化させたものである。また、蛍光体層の形成に使用した蛍光体インキは、表１に示す各蛍光体粒子を使用して上述した例で示すような混合比で蛍光体、樹脂、溶剤、分散剤を混合して作製した。
【０１０２】
さらに、サンプル１０，１１は比較例で、赤色蛍光体に（Ｙ，Ｇｄ）_1-xＢＯ₃：Ｅｕ₂，緑色蛍光体に（Ｚｎ₂ＳｉＯ₄：Ｍｎ_x）をそれぞれ水熱合成法で作製し、青色蛍光体はＣａＭｇＳｉ₂Ｏ₆：Ｅｕ（サンプル１０）とＢａＭｇＡｌ₁₀Ｏ₁₇：Ｅｕ（サンプル１１）を固相反応法で作製したものを用いた組み合わせのものであり、上記サンプル１〜９と同様の条件で蛍光体層を作製したものである。
【０１０３】
そのときの蛍光体インキの粘度（２５℃）について測定した結果、いずれも粘度が１５００ＣＰ〜３００００ＣＰの範囲に保たれている。形成された蛍光体層を観察したところ、いずれも隔壁壁面に均一に蛍光体インキが塗布されていた。また、各色における蛍光体層に使用される蛍光体粒子については、表１に示すような組成、製造方法が各サンプルに使用されている。
【０１０４】
次に、比較サンプル１０，１１の青色蛍光体粒子には、従来から行われている焼結工程を用い、固相反応を行った蛍光体粒子をボールミルで粉砕した後、ふるいわけにより得られるものを用いた。赤色蛍光体には、サンプル９と同じ水熱合成方法で作製した粒径２．０μｍの球状のＹ₂Ｏ₃：Ｅｕ（表３参照）を使用し、膜厚は２０μｍとした。緑色蛍光体には、同じくサンプル９と同じ水熱合成方法で作製した粒子径２．２μｍの不定形のＢａ_1-xＡｌ₁₂Ｏ₁₉：Ｍｎ_xを使用し、膜厚は２０μｍとした。青色蛍光体には、従来例の焼結法で作製したＣａＭｇＳｉ₂Ｏ₆：ＥｕをＨ₂−Ｎ₂ガス中において１４００℃、５時間焼成した後、粉砕しふるいわけによって、得られる粒子径はそれぞれ４．０μｍとした。
【０１０５】
また、蛍光体層の形成に使用した蛍光体インキは、表１に示す各蛍光体粒子を使用して、蛍光体、樹脂、溶剤、分散剤を混合して作製した。
【０１０６】
このように作製されたサンプル１〜９および比較サンプル１０，１１について、ＰＤＰを作製する工程において、背面パネル工程での蛍光体焼成（条件は５２０℃、空気中）での各蛍光体の輝度劣化率、パネル封着工程（温度４５０℃で加熱）での蛍光体の輝度劣化率、パネルの加速寿命時の輝度劣化率、アドレス放電時のアドレスミスの有無及び青色全面点燈時の輝度等を計測した。
【０１０７】
ＰＤＰの輝度の測定については、パネルに電圧１５０Ｖ、周波数３０ｋＨｚの放電維持パルスを印加した状態で行った。
【０１０８】
輝度劣化変化率の測定は、ＰＤＰに電圧２００Ｖ、周波数１００ｋＨｚの放電維持パルスを１００時間連続して印加する場合に、その前後におけるパネル輝度を測定し、そこから輝度劣化変化率（＜〔印加後の輝度−印加前の輝度〕／印加前の輝度＞×１００）を求めた。
【０１０９】
また、アドレス放電時のアドレスミスについては画像を見てちらつきがあるかないかで判断し、１個所でもあれば、ありとしている。パネルの輝度分布については、白表示時の輝度を輝度計で測定して、その全面の分布を示した。
【０１１０】
これらの輝度および輝度劣化変化率についての結果を表２に示す。なお、実験においては、各色蛍光体層に均等に放電を行っており、白表示したときの色温度を調整するために赤、緑色のセルの輝度を抑えるという制御は行っていない。
【０１１１】
【表２】

【０１１２】
表２に示すように、比較サンプル１０，１１においては、従来の青色の蛍光体焼成時（５２０℃）の、輝度劣化変化率がそれぞれ−４．６％、−５．６％、パネル封着工程（４５０℃）の輝度の劣化率がそれぞれ−１４．５％、−２１．８％で、放電維持パルス１００時間印加後の輝度変化がそれぞれ−１１．０％、−３４．６％で、アドレス放電ミスあり、パネルの青色輝度がそれぞれ６１，４６ｃｄ／ｃｍ²の値を示した。
【０１１３】
一方、青色蛍光体にＭｅ_1-xＭｇＳｉ₂Ｏ₆：Ｅｕ_x構造の蛍光体を使用したサンプル１〜９については、青色全面点燈の輝度が軒並み８０ｃｄ／ｃｍ²を超える値を示した。また、蛍光体焼成時（５２０℃）の輝度劣化変化率は、−０．２〜−２．８％、パネル封着工程時（４５０℃）の輝度変化率は−０．３〜−５．０％で、放電維持パルス１００時間印加後の輝度変化率が、−０．２〜−０．９％で、アドレスミスもなかった。
【０１１４】
すなわち、本発明品は、比較サンプル１０，１１に比べ、パネル輝度、各種工程の輝度劣化及びアドレス放電ミスについても優れた特性を示す。
【０１１５】
これは、本発明による青色蛍光体粒子が、水溶液中合成法、水熱合成法、噴霧合成法、加水分解法を用いたＭｅ_1-xＭｇＳｉ₂Ｏ₆：Ｅｕ_x（ただしＭｅは、Ｃａ，Ｓｒ，Ｂａの内のいずれか一種以上）の結晶構造を有する蛍光体であることにより、比較的小さな（０．１μｍ〜３．０μｍ）略球状の蛍光体粒子が合成されるので、粒子の粉砕が不要となり酸素欠陥の発生が抑制されるうえ、蛍光体層における蛍光体粒子の充填度が向上し、発光に寄与する蛍光体粒子の表面が増加したためと考えられる。特に、Ｃａ単独よりもその一部または全部をＣａ，Ｂａで置換したパネルの方が輝度や各種特性が向上する。
【０１１６】
つまり、この青色蛍光体粒子において酸素欠陥発生が抑制されることにより、酸素欠陥を起点とした結晶性の低下が進行しにくくなり、特に青色の色温度の劣化及び輝度劣化が抑制されるとともに、酸素欠陥に吸収される紫外線量が少なくなることから、発光中心の励起が行われやすくなるために従来に比べて輝度が向上すると考えられる。
【０１１７】
（評価実験２）
上記評価実験１においては、本発明に係る蛍光体をＰＤＰに用いたが、同じく紫外線により励起されることにより発光する蛍光灯に本発明に係る蛍光体を用いた蛍光灯サンプルを作製した。
【０１１８】
公知の蛍光灯において、ガラス管内壁に形成される蛍光体層として、上記表１に示すサンプル４の条件下で作製した各色の蛍光体を混合したものを塗布することによって得られる蛍光体層を用い、蛍光灯サンプル１２を作製した。比較例として、従来の固相反応で反応するサンプル１１（表１）の条件下で作製した各色蛍光体を混合したものを塗布した比較蛍光灯サンプル１３も同様に作製した。
【０１１９】
この評価実験２の蛍光灯サンプル１２、および比較蛍光灯サンプル１３に対して、１００Ｖ，６０Ｈｚのパルス電圧を５０００時間印加する前後における輝度を測定し、その輝度から輝度変化率（＜〔印加後の輝度−印加前の輝度〕／印加前の輝度＞×１００）を算出した。その結果を表３に示す。
【０１２０】
【表３】

【０１２１】
この表３の結果から、水溶液中で球状の前駆体を作製し、次にこれを用いて噴霧合成法、水熱合成法、加水分解法等で作製したＭｅ_1-xＭｇＳｉ₂Ｏ₆：Ｅｕ_x構造を有する青色蛍光体粒子を使用した蛍光灯サンプル１２は、蛍光灯サンプル１３と比較すると、輝度が約４％向上し、輝度変化率においては大幅に優れていることがわかる。
【０１２２】
（評価実験３）
次に、Ｍｅ_3(1-x)ＭｇＳｉ₂Ｏ₈：Ｅｕ_x構造の蛍光体を用いたプラズマディスプレイ装置の性能を評価するために、上記評価実験１と同様に、サンプルを作製し、そのサンプルについて性能評価実験を行った実験結果を表４に示す。
【０１２３】
【表４】

【０１２４】
サンプル１〜４は、赤色蛍光体に（Ｙ，Ｇｄ）_1-xＢＯ₃：Ｅｕ_x、緑色蛍光体に（Ｚｎ_2-xＳｉＯ₄：Ｍｎ_x）、青色蛍光体に〔Ｍｅ_3(1-x)ＭｇＳｉ₂Ｏ₈：Ｅｕ_x（Ｍｅは、Ｃａ，Ｓｒ，Ｂａの組み合わせ）〕を用いた組み合わせのものであり、蛍光体の製造方法および発光中心となるＥｕ，Ｍｎの置換比率、すなわちＹ，Ｍｅ元素に対するＥｕの置換比率、およびＺｎ元素に対するＭｎの置換比率及びＭｅの組み合わせを表４のように変化させたものである。
【０１２５】
サンプル５〜９は、赤色蛍光体に（Ｙ_2-xＯ₃：Ｅｕ_x）、緑色蛍光体に（Ｂａ_1-xＡｌ₁₂Ｏ₁₉：Ｍｎ_x）、青色蛍光体に〔〔Ｍｅ_3(1-x)ＭｇＳｉ₂Ｏ₈：Ｅｕ_x（Ｍｅは、Ｃａ，Ｓｒ，Ｂａの組み合わせ）〕を用いた組み合わせのものであり、上記と同様、水熱合成方法、噴霧合成方法、加水分解方法で合成された前駆体を用いて作製した蛍光体である。また、発光中心の置換比率及びＭｅの組み合わせを表４のように変化させたものである。また、蛍光体層の形成に使用した蛍光体インキは、表４に示す各蛍光体粒子を使用して上述した例で示すような混合比で蛍光体、樹脂、溶剤、分散剤を混合して作製した。
【０１２６】
さらに、サンプル１０，１１，１２は比較例で、赤色蛍光体に〔（Ｙ_1-x）₂Ｏ₃：Ｅｕ₂，緑色蛍光体に（Ｂａ_1-xＡｌ₁₂Ｏ₁₉：Ｍｎ_x）をそれぞれ水熱合成法で作製し、青色蛍光体はＢａ₃ＭｇＳｉ₂Ｏ₈：Ｅｕ（サンプル１０），ＢａＭｇＡｌ₁₀Ｏ₁₇：Ｅｕ（サンプル１１），ＣａＭｇＳｉ₂Ｏ₆：Ｅｕ（サンプル１２）を固相反応法で作製したものを用いた組み合わせのものであり、上記サンプル１〜９と同様の条件で蛍光体層を作製したものである。
【０１２７】
そのときの蛍光体インキの粘度（２５℃）について測定した結果、いずれも粘度が１５００ＣＰ〜３００００ＣＰの範囲に保たれている。形成された蛍光体層を観察したところ、いずれも隔壁壁面に均一に蛍光体インキが塗布されていた。また、各色における蛍光体層に使用される蛍光体粒子については、表４に示すような組成、製造方法が各サンプルに使用されている。
【０１２８】
次に、比較サンプル１０，１１，１２の青色蛍光体粒子には、従来から行われている焼結工程を用い、固相反応を行った蛍光体粒子をボールミルで粉砕した後、ふるいわけにより得られるものを用いた。赤色蛍光体には、サンプル９と同じ水熱合成方法で作製した粒径２．０μｍの球状のＹ₂Ｏ₃：Ｅｕを使用し、膜厚は２０μｍとした。緑色蛍光体には、同じくサンプル９と同じ水熱合成方法で作製した粒子径２．２μｍの不定形のＢａ_1-xＡｌ₁₂Ｏ₁₉：Ｍｎ_xを使用し、膜厚は２０μｍとした。青色蛍光体には、従来例の焼結法で作製したＢａ₃ＭｇＳｉ₂Ｏ₈：Ｅｕ（サンプル１０），ＢａＭｇＡｌ₁₀Ｏ₁₇：Ｅｕ（サンプル１１），ＣａＭｇＳｉ₂Ｏ₆：Ｅｕ（サンプル１２）をＨ₂−Ｎ₂ガス中において１４００℃、５時間焼成した後、粉砕しふるいわけによって、得られる粒子径はそれぞれ４．０μｍとした。
【０１２９】
また、蛍光体層の形成に使用した蛍光体インキは、表４に示す各蛍光体粒子を使用して、蛍光体、樹脂、溶剤、分散剤を混合して作製した。
【０１３０】
このように作製されたサンプル１〜９および比較サンプル１０，１１，１２について、評価実験１と同様に、背面パネル工程での蛍光体焼成（条件は５２０℃、空気中）での各蛍光体の輝度劣化率、パネル封着工程（温度４５０℃で加熱）での蛍光体の輝度劣化率、パネルの加速寿命時の輝度劣化率、アドレス放電時のアドレスミスの有無及び青色全面点燈時の輝度等を計測した。
【０１３１】
これらの輝度および輝度劣化変化率についての結果を表５に示す。なお、実験においては、各色蛍光体層に均等に放電を行っており、白表示したときの色温度の調整をするために赤、緑色のセルの輝度を抑えるという制御は行っていない。
【０１３２】
【表５】

【０１３３】
表５に示すように、比較サンプル１０，１１，１２においては、従来の青色の蛍光体焼成時（５２０℃）の、輝度劣化変化率がそれぞれ−３．６％、−５．６％、−４．６％、パネル封着工程（４５０℃）の輝度の劣化率がそれぞれ−１２．５％、−２１．８％、−１４．５％で、放電維持パルス１００時間印加後の輝度変化がそれぞれ−１０．５％、−３４．６％、−１１．０％で、アドレス放電ミスあり、パネルの青色輝度がそれぞれ６５，４６，６１ｃｄ／ｃｍ²の値を示した。
【０１３４】
一方、青色蛍光体にＭｅ_3(1-x)ＭｇＳｉ₂Ｏ₈：Ｅｕ_x構造の蛍光体を使用したサンプル１〜９については、青色全面点燈の輝度が軒並み８３ｃｄ／ｃｍ²を超える値を示した。また、青色蛍光体焼成時（５２０℃）の輝度劣化変化率は、−０．２〜−１．８％、パネル封着工程時（４５０℃）の輝度変化率は−０．２〜−３．０％で、放電維持パルス１００時間印加後の輝度変化率が、−０．２〜−０．５％で、アドレスミスもなかった。
【０１３５】
すなわち、本発明品は、比較サンプル１０，１１，１２に比べ、パネル輝度、各種工程の輝度劣化及びアドレス放電ミスについても優れた特性を示す。
【０１３６】
これは、本発明による青色蛍光体粒子が、水溶液中合成法、水熱合成法、噴霧合成法、加水分解法を用いて合成した前駆体で作製したＭｅ_3(1-x)ＭｇＳｉ₂Ｏ₈：Ｅｕ_x（ただしＭｅは、Ｃａ，Ｓｒ，Ｂａの内のいずれか一種以上）の結晶構造を有する蛍光体であることにより、比較的小さな（０．１μｍ〜３．０μｍ）略球状の蛍光体粒子が合成されるので、粒子の粉砕が不要となり酸素欠陥の発生が抑制されるうえ、蛍光体層における蛍光体粒子の充填度が向上し、発光に寄与する蛍光体粒子の表面が増加したためと考えられる。特に、Ｂａ単独よりもその一部または全部をＣａ，Ｓｒで置換したパネルの方が輝度や各種特性が向上する。
【０１３７】
つまり、この青色蛍光体粒子において酸素欠陥発生が抑制されることにより、酸素欠陥を起点とした結晶性の低下が進行しにくくなり、特に青色の色温度の劣化及び輝度劣化が抑制されるとともに、酸素欠陥に吸収される紫外線量が少なくなることから、発光中心の励起が行われやすくなるために従来に比べて輝度が向上すると考えられる。
【０１３８】
（評価実験４）
上記評価実験３の蛍光体について、同じく紫外線により励起されることにより発光する蛍光灯に用いた蛍光灯サンプルを作製した。評価実験２と同様に、公知の蛍光灯において、ガラス管内壁に形成される蛍光体層として、上記表４に示すサンプル４の条件下で作製した各色の蛍光体を混合したものを塗布することによって得られる蛍光体層を用い、蛍光灯サンプル１２を作製した。比較例として、従来の固相反応で反応するサンプル１１（表４）の条件下で作製した各色蛍光体を混合したものを塗布した比較蛍光灯サンプル１３も同様に作製した。
【０１３９】
この評価実験４の蛍光灯サンプル１２、および比較蛍光灯サンプル１３に対して、１００Ｖ，６０Ｈｚのパルス電圧を５０００時間印加する前後における輝度を測定し、その輝度から輝度変化率（＜〔印加後の輝度−印加前の輝度〕／印加前の輝度＞×１００）を算出した。その結果を表６に示す。
【０１４０】
【表６】

【０１４１】
この表６の結果から、水溶液中で球状の前駆体を作製し、次にこれを用いて噴霧合成法、水熱合成法、加水分解法等で作製したＭｅ_3(1-x)ＭｇＳｉ₂Ｏ₈：Ｅｕ_x構造を有する青色蛍光体粒子を使用した蛍光灯サンプル１２は、蛍光灯サンプル１３と比較すると、輝度が約４％向上し、輝度変化率においては大幅に優れていることがわかる。
【０１４２】
【発明の効果】
以上述べたように本発明によれば、水溶液中合成法、水熱合成法、噴霧合成法で作製されたＭｅ_1-xＭｇＳｉ₂Ｏ₆：Ｅｕ_x構造またはＭｅ_3(1-x)ＭｇＳｉ₂Ｏ₈：Ｅｕ_x構造（Ｍｅは、Ｃａ，Ｓｒ，Ｂａの内のいずれか一種以上）を有する青色蛍光体粒子で蛍光体層を構成することによって、蛍光体層の紫外線を吸収する効率の向上を図り、プラズマディスプレイ装置やランプなどの照明装置の輝度、寿命及び信頼性を向上させることができる。
【図面の簡単な説明】
【図１】本発明の一実施の形態によるプラズマディスプレイパネルの前面ガラス基板を除いた状態を示す平面図
【図２】同じく画像表示領域の構造を示す斜視図
【図３】本発明の一実施の形態によるプラズマディスプレイ装置のブロック図
【図４】同じくプラズマディスプレイパネルの画像表示領域の構造を示す断面図
【図５】本発明において蛍光体層を形成する際に用いるインキ塗布装置の概略構成図
【符号の説明】
１００ ＰＤＰ
１０１ 前面ガラス基板
１０３ 表示電極
１０４ 表示スキャン電極
１０５ 誘電体ガラス層
１０６ ＭｇＯ保護層
１０７ アドレス電極
１０８ 誘電体ガラス層
１０９ 隔壁
１１０ 蛍光体層[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a plasma display device used for image display such as a television.
[0002]
[Prior art]
2. Description of the Related Art In recent years, color display devices using plasma display panels (hereinafter referred to as “PDP”) in color display devices used for image display such as computers and televisions are color displays that can be large, thin, and lightweight. It is attracting attention as a device.
[0003]
The PDP performs full color display by additively mixing so-called three primary colors (red, green, and blue). In order to perform this full-color display, the PDP is provided with a phosphor layer that emits each of the three primary colors red (R), green (G), and blue (B), and the phosphor constituting the phosphor layer. The particles are excited by ultraviolet rays generated in the discharge cell of the PDP, and generate visible light of each color.
[0004]
As a compound used for the phosphors of the above colors, for example, (Y, Gd) BO emitting red light_Three: Eu³⁺, Y₂O_Three: Eu³⁺Zn that emits green light₂SiO_Four: Mn²⁺BaMgAl emitting blue light_TenO₁₇: Eu²⁺Or CaMgSi₂O₆: Eu etc. are known. Each of these phosphors is produced by mixing a predetermined raw material and then performing a solid phase reaction by firing at a high temperature of 1000 ° C. or higher (see, for example, Non-Patent Document 1). Since the phosphor particles obtained by this firing are sintered by firing, they are crushed and sieved (red and green average particle size: 2 μm to 5 μm, blue average particle size: 3 μm to 10 μm). It has been used since then.
[0005]
[Non-Patent Document 1]
Phosphor Handbook P219, 225 Ohmsha
[0006]
[Problems to be solved by the invention]
However, BaMgAl, which is a conventional phosphor, especially a blue phosphor_TenO₁₇: Eu has a problem in that the phosphor brightness decreases when heating in the phosphor layer forming step or when driving the panel. CaMgSi₂O₆: Blue phosphor with Eu-based crystal structure has a slight decrease in luminance when heated in the phosphor formation process or when the panel is driven, but the luminance is low in the synthesis method and crystal composition by the conventional solid-phase reaction method. In addition, there is a problem that the luminance is greatly deteriorated when the panel is driven. This is CaMgSi₂O₆: When the blue phosphor having the Eu crystal structure has a low melting point, sintering is more likely to proceed, and if particles of 8 μm or less are to be produced by the solid phase reaction method, it is necessary to pulverize them. CaMgSi₂O₆: The optimum firing temperature in the solid phase reaction of Eu crystal is around 1400 ° C. as a phosphor, but at this temperature, the grain growth is intense and the grain size becomes several tens of μm. Sintered CaMgSi₂O₆: When Eu is pulverized and the particle size is reduced to 3 μm or less, defects in the crystal increase and the luminance is greatly reduced. Therefore, an actual panel with high luminance and less luminance deterioration during operation is obtained. It is not done. In addition, the deterioration of the life characteristics of the panel is severe.
[0007]
In view of the above-described problems, the present invention aims to improve the luminance of a blue phosphor and reduce luminance deterioration.
[0008]
[Means for Solving the Problems]
  In order to achieve this object, in the present invention, in the plasma display device, the blue phosphor in the phosphor layer is synthesized by any one of an aqueous solution synthesis method, a spray synthesis method, a hydrothermal synthesis method, and a hydrolysis method. MeMgSi prepared using different precursors₂O₆: Eu or Me_ThreeMgSi₂O₈: Eu (where Me is one or more of Ca, Sr, and Ba), and has an average particle size of 0.1 μm to 3.0 μm. In hydrothermal synthesis,It is characterized in that the temperature is 100 ° C. to 300 ° C. and the pressure is 0.2 MPa to 10 MPa. In the synthesis method in an aqueous solution, a mixed solution preparation step of preparing a mixed solution by mixing a raw material and an aqueous medium, the mixed solution and a basic aqueous solution are applied to a vibrating container with ultrasonic waves, and oxygen or ozone is applied. A precursor forming step of forming a hydrate by mixing with bubbling, a step of drying the hydrate in air at 800 ° C. to 1450 ° C., and 1000 ° C. to 1400 ° C. in a reducing atmosphere. And a step of firing.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
That is, MeMgSi that emits visible light when excited by ultraviolet rays.₂O₆: Eu or Me_ThreeMgSi₂O₈: Eu-based blue phosphor (Me is one or more of Ca, Sr, and Ba), which is not a conventional solid-phase reaction method, but a part of Ca in an aqueous solution or gas phase MeMgSi with all replaced with Sr, Ba₂O₆: Eu, or Me in which Ba is partially or entirely replaced with Sr, Ca in aqueous solution or gas phase_ThreeMgSi₂O₈: A precursor (in particular, a spherical precursor) of Eu (where Me is any one or more of Ca, Sr, and Ba) is prepared, and this is heat-treated to prepare a phosphor.
[0010]
That is, in the mixed solution preparation step of preparing a mixed solution by mixing the raw material and the aqueous medium, and in the step of preparing the mixed solution, oxygen (O₂) Or ozone (O_Three) To form a spherical hydrate (hydrate precursor) by mixing with a basic aqueous solution while bubbling), the hydrate (phosphor precursor) and water. A process in which phosphor is obtained by heat treatment (hydrothermal synthesis or firing in a reducing atmosphere) or a solution in which the hydrate and water are mixed is sprayed into a heated furnace to form a spherical shape. The method includes a step of obtaining a phosphor precursor, a step of annealing the obtained phosphor precursor, and a step of classifying the phosphor.
[0011]
Conventional CaMgSi used in PDP₂O₆: Eu or Ba_ThreeMgSi₂O₈: Since Eu-based blue phosphor particles are produced by pulverization after solid-phase reaction, the surface of the phosphor particles is distorted by stress and many defects such as oxygen defects are generated. appear. This defect such as oxygen adsorbs water in the atmosphere in the panel manufacturing process, and this water and the phosphor react in the panel at the time of temperature rise when sealing the panel to lower the luminance of the phosphor. Moreover, this water reacts with MgO in the panel to cause an address discharge error. In addition, this defect absorbs ultraviolet light having a wavelength of 147 nm generated by discharge in the cell of the PDP and inhibits excitation of the emission center, resulting in a decrease in luminance.
[0012]
Therefore, the more the phosphor particles are pulverized, the more the absolute number of oxygen defects in the entire phosphor layer increases. Therefore, luminance deterioration and address discharge errors are likely to occur, and sufficiently high luminance cannot be obtained.
[0013]
The present invention is MeMgSi₂O₆: Eu or Me_ThreeMgSi₂O₈: Eu structure phosphor (wherein Me is one or more of Ca, Sr, and Ba), an aqueous solution synthesis method, a hydrothermal synthesis method, a spray method or a hydrolysis method in which spherical particles can be easily obtained. Even if heat treatment is performed to make this phosphor spherical precursor into a phosphor at a high temperature of 1000 ° C. to 1400 ° C., since the precursor is spherical, particles are difficult to stick together during sintering, A phosphor can be obtained while maintaining the spherical shape. Accordingly, since the phosphor is less pulverized, it is possible to obtain a blue phosphor with few defects and good luminance and lifetime characteristics. In addition, by replacing a part of Ca with Sr and Ba or a part of Ba with Sr and Ca, the luminance and life characteristics can be further improved.
[0014]
On the other hand, since the phosphor formed by the manufacturing method according to the present invention has a sufficiently small particle size, a uniform and narrow particle size distribution, and a good crystallinity, the phosphor particles that form the phosphor layer are filled. The density is improved over the conventional method, and the light emission area of the phosphor particles that substantially contribute to light emission increases. Moreover, there is little deterioration by discharge. Therefore, even if the discharge space is narrower than before, the brightness equal to or higher than that of the conventional PDP can be obtained. When this blue phosphor is used for the phosphor layer of the PDP, ultraviolet rays are absorbed in oxygen defects. In addition, the excitation of the luminescent center is likely to occur, the luminance is improved, and the phosphor has good crystallinity, so that oxygen defects are less likely to occur in the phosphor. It becomes difficult for the temperature to deteriorate.
[0015]
Here, as a specific manufacturing method of the blue phosphor, Ba (NO_Three)₂, Ca (NO_Three)₂, Sr (NO_Three)₂, SiO₂(Colloidal silica) and ethyl silicate [Si (O · C₂H_Five)_Four] And Eu (NO_Three)₂In the precursor synthesis step in an alkaline aqueous solution, while applying ultrasonic waves, O₂Or O_ThreeAre mixed to produce a spherical phosphor precursor, which is then fired in air at 1000 ° C. to 1400 ° C. and then fired in a reducing atmosphere at 1000 ° C. to 1400 ° C. There is a synthesis method in an aqueous solution for producing a body.
[0016]
In addition, a spherical phosphor precursor is produced by spraying droplets of this solution in a furnace heated to 1000 ° C. to 1500 ° C. with an alkaline aqueous solution containing the phosphor raw material, and this is then subjected to 1000 ° C. in a reducing atmosphere. There is a spray synthesis method in which a spherical phosphor is produced by firing at ˜1400 ° C.
[0017]
Moreover, the alkaline solution containing the phosphor raw material is put in a high-pressure vessel and synthesized by applying a pressure of 0.2 MPa to 10 MPa at a temperature of 100 ° C. to 300 ° C., and then synthesized in a reducing atmosphere at 1000 ° C. to 1400 ° C. There is a hydrolytic synthesis method in which a phosphor is produced by heat treatment.
[0018]
Further, a phosphor spherical precursor using a hydrolysis reaction from a mixture of an organic compound (metal acetylacetone, metal alkoxide) containing an element of Ca, Sr, Ba, Si, Eu as a phosphor raw material with alcohol and water. Then, the precursor is heated at 1000 ° C. to 1400 ° C., and then calcined at 1000 ° C. to 1400 ° C. in a reducing atmosphere to produce a spherical phosphor.
[0019]
As a specific method for producing the green phosphor, for example, Zn (NO_Three), Mn (NO_Three)₂, And colloidal silica (SiO₂), And a spherical precursor is prepared from an aqueous solution of these raw materials in the same manner as in the synthesis of the blue phosphor. In the hydrothermal synthesis process using this, a temperature of 100 ° C. to 300 ° C., 0.2 MPa to 10 MPa is used. A hydrothermal synthesis reaction is performed in a state where pressure is applied, and then the obtained powder is heat-treated in air and then classified. As another method, Ba (NO_Three)₂, Mn (NO_Three)₂, And Al (NO_Three)₂In the hydrothermal synthesis step, the hydrothermal synthesis reaction may be performed in a state where a temperature of 100 ° C. to 300 ° C. and a pressure of 0.2 MPa to 10 MPa are applied.
[0020]
Moreover, as a specific manufacturing method of the red phosphor,₂(NO_Three)_ThreeAnd Eu (NO_Three)_ThreeOr Y₂(OH)_ThreeAnd H_ThreeBO_Three, Gd₂(OH)_ThreeAnd Eu₂(OH)_ThreeIn the hydrothermal synthesis step, a hydrothermal synthesis reaction is performed in a state where a temperature of 100 ° C. to 300 ° C. and a pressure of 0.2 MPa to 10 MPa is applied, and then the obtained powder is heat-treated in air, After that, classification is sufficient.
[0021]
Thus, phosphor particles produced using a spherical precursor rather than the conventional solid-phase reaction synthesis have a uniform particle size distribution in order to suppress fusion of the phosphor particles in the firing step.
[0022]
In the present invention, nitric acid compounds and hydroxide compounds are used as starting materials, but other compounds such as metal alkoxides M (O · R) are used.₂And acetylacetone M (C_FiveH₇O)₂However, it can also be produced using M (wherein M is a metal).
[0023]
As described above, in the plasma display device according to the present invention, a plurality of discharge cells of one color or a plurality of colors are arranged, and a phosphor layer of a color corresponding to each discharge cell is disposed. A PDP that emits light when excited, and a drive circuit that drives the PDP. The phosphor layer includes an aqueous solution synthesis method, a hydrothermal synthesis method, and a spray synthesis with a uniform particle size distribution. It is composed of phosphor particles prepared using precursors synthesized by the method, hydrolysis method, etc., and hydrothermal synthesis method, spray synthesis method, or hydrolysis method using spherical precursors Phosphor particles, especially blue phosphors, are formed in a spherical shape immediately after synthesis, have a small particle size of 0.05 μm to 3 μm, and have a good particle size distribution. Forming a layer The packing density of the phosphor particles is improved, and the light emitting area of the phosphor particles that substantially contributes to light emission is increased. Therefore, even if the discharge space of the PDP is 1/3 of the conventional one and the film thickness of the phosphor is 1/3 of the conventional one, the luminance of the PDP is improved and the luminance deterioration is suppressed and the PDP having excellent luminance characteristics is obtained. be able to. In particular, BaMgAl, which has been greatly deteriorated in luminance._TenO₁₇: MeMgSi instead of blue phosphor with Eu structure₂O₆: Eu structure or Me_ThreeMgSi₂O₈: By using a blue phosphor having an Eu structure (Me is one or more of Ca, Ba and Sr), various deteriorations can be greatly improved.
[0024]
Here, the average particle size of the phosphor particles is preferably in the range of 0.1 μm to 3.0 μm, and the particle size distribution preferably has a maximum particle size of 8 μm or less and a minimum value of 1/4 or more of the average value. The region where the ultraviolet rays reach in the phosphor particles is as shallow as about several hundred nm from the particle surface, and only the surface emits light. If the particle size of such phosphor particles is 3.0 μm or less, it contributes to light emission. The surface area of the particles is increased and the luminous efficiency of the phosphor layer is kept high. On the other hand, when the thickness is 3.0 μm or more, the thickness of the phosphor is required to be 20 μm or more, and a sufficient discharge space cannot be ensured.
[0025]
Moreover, if the thickness of the phosphor layer is within a range of 8 to 25 times the average particle diameter of the phosphor particles, a sufficient discharge space can be secured while maintaining a high luminous efficiency of the phosphor layer. The brightness in the PDP can be increased. In particular, when the average particle size of the phosphor is 3 μm or less, the effect is large (Image Information Society of Japan IDY2000-317.PP32).
[0026]
Here, specific phosphor particles used for the blue phosphor layer in the PDP are Ca_1-xMgSi₂O₆: Eu_x, Sr_1-xMgSi₂O₆: Eu_x, Ba_1-xMgSi₂O₆: Eu_x, (Ca, Sr)_1-xMgSi₂O₆: Eu_xOr (Ca, Ba)_1-xMgSi₂O₆: Eu_x, (Ca, Sr, Ba)_1-xMgSi₂O₆: Eu_xThe compound represented by these can be used. Here, the value of X in the compound is preferably 0.03 ≦ X ≦ 0.20.
[0027]
Specific phosphor particles used for the red phosphor layer in the PDP include Y_2xO_Three: Eu_xOr (Y, Gd)_1-xBO_Three: Eu_xThe compound represented by these can be used. If the value of X in this red phosphor compound is 0.05 ≦ X ≦ 0.20, it is excellent in luminance and luminance deterioration, and is preferable.
[0028]
Specific phosphor particles used for the green phosphor layer in the PDP include Ba._1-xAl₁₂O₁₉: Mn_xOr Zn_2-xSiO_Four: Mn_xThe compound represented by these can be used. The value of X in this green phosphor compound is preferably 0.01 ≦ X ≦ 0.10 because it is excellent in luminance and luminance degradation.
[0029]
In addition, the method for producing a PDP according to the present invention includes a phosphor prepared on a first panel substrate using a precursor obtained by an aqueous synthesis method, a hydrothermal synthesis method, a spray synthesis method, a hydrolysis method, or the like. A disposing step of disposing a paste composed of particles and a binder; a firing step of burning out the binder contained in the paste disposed on the first panel; and the phosphor particles being disposed on the substrate by the firing step. A step of superimposing and sealing the first panel and the second panel provided, and thereby a PDP excellent in luminance and luminance degradation can be obtained.
[0030]
The fluorescent lamp to which the present invention is applied is a fluorescent lamp having a phosphor layer that emits visible light when excited by ultraviolet rays, and the phosphor layer is spherical and is synthesized in an aqueous solution, a hydrothermal synthesis method, It is characterized by including phosphor particles produced using precursors synthesized by spray synthesis method and hydrolysis method, and phosphor particles themselves have excellent light emission characteristics by being configured in this way. Thus, a fluorescent lamp excellent in luminance and luminance deterioration can be obtained.
[0031]
Hereinafter, an embodiment of a plasma display device according to the present invention will be described with reference to the drawings.
[0032]
FIG. 1 is a schematic plan view of the PDP with the front glass substrate removed, and FIG. 2 is a perspective view showing a part of the image display area of the PDP in cross section. In FIG. 1, the number of display electrode groups, display scan electrode groups, address electrode groups, and the like are not illustrated in order to facilitate understanding.
[0033]
In FIG. 1, a PDP 100 has a front glass substrate 101 (not shown), a back glass substrate 102, N display electrodes 103, and N display scan electrodes 104 (when the Nth is shown, the numerals are given. ), A group of M address electrodes 107 (indicated by the number when the M-th is shown), an airtight seal layer 121, and the like, and an electrode matrix having a three-electrode structure is formed by the electrodes 103, 104, and 107. A cell is formed at the intersection of the display scan electrode 104 and the address electrode 107. Reference numeral 123 denotes an image display area.
[0034]
As shown in FIG. 2, the PDP 100 includes a front panel in which a display electrode 103, a display scan electrode 104, a dielectric glass layer 105, and an MgO protective layer 106 are disposed on one main surface of a front glass substrate 101; A front panel and a rear panel are arranged opposite to each other on one main surface of the glass substrate 102 with an address electrode 107, a dielectric glass layer 108, barrier ribs 109, and a rear panel on which R, G, and B phosphor layers 110 are disposed. A discharge gas is enclosed in a discharge space 122 formed between and a plasma display device is configured by connecting a drive circuit to the PDP.
[0035]
In this plasma display device, as shown in FIG. 3, a display driver circuit 153, a display scan driver circuit 154, and an address driver circuit 155 that constitute the drive circuit 150 are connected to the PDP 100, and the PDP 100 is lit under the control of the controller 152. By applying a voltage to the display scan electrode 104 and the address electrode 107 for the cell to be subjected to address discharge between them, a pulse voltage is applied between the display electrode 103 and the display scan electrode 104 to cause a sustain discharge. Do. Due to this sustain discharge, ultraviolet light is generated in the cell of the PDP, the phosphor layer excited by the ultraviolet light emits light, and the cell is turned on, and an image is displayed by a combination of lighting and non-lighting of each color cell.
[0036]
Next, a manufacturing method of the above-described PDP will be described with reference to FIGS.
[0037]
After the front panel is formed on the front glass substrate 101, first, each of the N display electrodes 103 and the display scan electrodes 104 (only two are displayed in FIG. 2) are alternately and parallelly formed in stripes. The dielectric glass layer 105 is covered with the dielectric glass layer 105, and the MgO protective layer 106 is formed on the surface of the dielectric glass layer 105.
[0038]
The display electrode 103 and the display scan electrode 104 are electrodes made of silver, and are formed by applying a silver paste for electrodes by screen printing and then baking.
[0039]
The dielectric glass layer 105 is formed by applying a paste containing a lead-based glass material by screen printing, and then baking it at a predetermined temperature for a predetermined time, for example, 560 ° C. for 20 minutes to obtain a predetermined layer thickness (about 20 μm). It forms so that it may become. Examples of the paste containing the lead-based glass material include PbO (70 wt%), B₂O_Three(15 wt%), SiO₂(10 wt%), and Al₂O_ThreeA mixture of (5 wt%) and an organic binder (10% ethyl cellulose dissolved in α-terpineol) is used. Here, the organic binder is obtained by dissolving a resin in an organic solvent. In addition to ethyl cellulose, an acrylic resin can be used as the resin, and butyl carbitol can be used as the organic solvent. Further, a dispersant such as glyceryl trioleate may be mixed in such an organic binder.
[0040]
The MgO protective layer 106 is made of magnesium oxide (MgO), and is formed to have a predetermined thickness (about 0.5 μm) by, for example, a sputtering method or a CVD method (chemical vapor deposition method).
[0041]
The rear panel is formed in such a manner that M address electrodes 107 are arranged on the rear glass substrate 102 by screen printing a silver paste for electrodes and then firing the paste. After that, a dielectric glass layer 108 is formed by applying a paste containing a lead-based glass material by a screen printing method, and a paste containing the lead-based glass material is repeatedly applied at a predetermined pitch by a screen printing method. The partition wall 109 is formed by firing. By the barrier ribs 109, the discharge space 122 is partitioned for each cell (unit light emitting region) in the line direction.
[0042]
FIG. 4 is a partial cross-sectional view of the PDP 100. As shown in FIG. 4, the gap dimension W of the partition wall 109 is defined to be about 130 μm to 240 μm according to the HD-TV having a constant value of 32 inches to 50 inches.
[0043]
And in the groove | channel between the partition 109, the red (R) obtained by the hydrothermal synthesis method, green (G), the hydrothermal synthesis method, the spray synthesis method, and the blue (B) obtained by the hydrolysis method Each phosphor particle is bound by applying a paste-like phosphor ink composed of each phosphor particle and an organic binder, and baking this at a temperature of 400 ° C. to 590 ° C. to burn off the organic binder. A phosphor layer 110 is formed. The thickness L in the stacking direction of the phosphor layer 110 on the address electrode 107 is preferably about 8 to 25 times the average particle diameter of each color phosphor particle. That is, in order to ensure the brightness (luminous efficiency) when a certain ultraviolet ray is irradiated to the phosphor layer, the phosphor layer needs to absorb the ultraviolet ray generated in the discharge space without transmitting it. It is desirable to maintain a thickness in which at least 8 layers, preferably about 20 layers, are laminated, and if the thickness is larger than that, the luminous efficiency of the phosphor layer is almost saturated and about 20 layers are laminated. This is because if the thickness exceeds the predetermined thickness, the discharge space 122 cannot be sufficiently secured. In addition, when non-spherical particles are used as long as the particle diameter is sufficiently small and nearly spherical, such as phosphor particles obtained by hydrothermal synthesis, spray synthesis, hydrolysis, etc. Even when the number of stacked layers is the same, the phosphor layer filling degree is increased and the total surface area of the phosphor particles is increased, so that the surface area of the phosphor particles contributing to the actual light emission in the phosphor layer is increased. Luminous efficiency increases. A method for synthesizing the phosphor layer 110 and phosphor particles used in the phosphor layer will be described later.
[0044]
The front panel and the back panel produced in this way are stacked so that each electrode of the front panel and the address electrode of the back panel are arranged to be orthogonal to each other, and the sealing glass is inserted around the periphery of the panel, It seals by baking this at about 450 degreeC for 10 to 20 minutes, and forming the airtight seal layer 121, for example. Then, once the inside of the discharge space 122 is high vacuum, for example, 1.1 × 10^-FourAfter evacuating to Pa, the PDP 100 is manufactured by enclosing a discharge gas, for example, a He—Xe-based or Ne—Xe-based inert gas at a predetermined pressure.
[0045]
FIG. 5 is a schematic configuration diagram of an ink coating apparatus used when the phosphor layer 110 is formed. As shown in FIG. 5, the ink coating apparatus 200 includes a server 210, a pressure pump 220, a header 230, and the like, and the phosphor ink supplied from the server 210 that stores the phosphor ink is sent from the header 230 by the pressure pump 220. Is supplied under pressure. The header 230 is provided with an ink chamber 230 a and a nozzle 240, and the phosphor ink pressurized and supplied to the ink chamber 230 a is continuously discharged from the nozzle 240. The diameter D of the nozzle 240 is desirably 30 μm or more for preventing clogging of the nozzle, and preferably not more than the interval W (about 130 μm to 200 μm) between the partition walls 109 for preventing protrusion from the partition wall during coating. It is set to 30 μm to 130 μm.
[0046]
The header 230 is configured to be linearly driven by a header scanning mechanism (not shown). By scanning the header 230 and continuously ejecting the phosphor ink 250 from the nozzle 240, the header 230 is placed on the rear glass substrate 102. The phosphor ink is uniformly applied to the grooves between the barrier ribs 109. Here, the viscosity of the phosphor ink used is maintained in the range of 1500 CP to 30000 CP at 25 ° C.
[0047]
The server 210 is provided with a stirring device (not shown), and the stirring prevents the precipitation of particles in the phosphor ink. The header 230 is integrally formed including the ink chamber 230a and the nozzle 240, and is manufactured by machine processing and electric discharge processing of a metal material.
[0048]
Further, the method for forming the phosphor layer is not limited to the above method, and various methods such as a photolithography method, a screen printing method, and a method of disposing a film in which phosphor particles are mixed may be used. Can be used.
[0049]
The phosphor ink is prepared by mixing phosphor particles of various colors, a binder, and a solvent so as to be 1500 to 30000 centipoise (CP). If necessary, a surfactant, silica, a dispersant ( 0.1 wt% to 5 wt%) or the like may be added.
[0050]
As the red phosphor to be prepared in this phosphor ink, (Y, Gd)_1-xBO_Three: Eu_xOr Y_2-xO_Three: Eu_xThe compound represented by these is used. These are compounds in which part of the Y element constituting the base material is substituted with Eu. Here, the substitution amount X of the Eu element with respect to the Y element is preferably in the range of 0.05 ≦ X ≦ 0.20. If the substitution amount is larger than this, the luminance is increased, but the luminance is significantly deteriorated. On the other hand, when the amount is less than this substitution amount, the composition ratio of Eu, which is the emission center, is lowered, the luminance is lowered, and the phosphor cannot be used.
[0051]
As the green phosphor, Ba_1-xAl₁₂O₁₉: Mn_xOr Zn_2-xSiO_Four: Mn_xThe compound represented by these is used. Ba_1-xAl₁₂O₁₉: Mn_xIs a compound in which a part of the Ba element constituting the base material is substituted with Mn, and Zn_2-xSiO_Four: Mn_xIs a compound in which a part of Zn element constituting the base material is substituted with Mn. Here, the substitution amount X of Mn element with respect to Ba element and Zn element is preferably in the range of 0.01 ≦ X ≦ 0.10 for the same reason as described for the red phosphor.
[0052]
As the blue phosphor, Me_1-xMgSi₂O₆: Eu_xOr Me_{3 (1-x)}MgSi₂O₈: Eu_xA compound represented by (Me is any one or more of Ca, Sr, and Ba) is used. These phosphors are compounds in which a part of the Me (Ca, Sr, Ba) element constituting the host material is substituted with Eu. Here, the substitution amount X of the Eu element with respect to the Me element is preferably in the range of 0.03 ≦ X ≦ 0.2 for the blue phosphor for the same reason as described above.
[0053]
For each of these color phosphors, phosphors (not subjected to a pulverization step) prepared using precursors obtained by an aqueous solution synthesis method, a hydrothermal synthesis method, a spray synthesis method, or a hydrolysis method are used. A method for synthesizing this phosphor will be described later.
[0054]
Ethyl cellulose or acrylic resin can be used as the binder to be prepared for the phosphor ink (mixed with 0.1 wt% to 10 wt% of the ink), and α-terpineol or butyl carbitol can be used as the solvent. A polymer such as PMA or PVA can be used as the binder, and water of an organic solvent such as diethylene glycol or methyl ether can be used as the solvent.
[0055]
In the present embodiment, a phosphor precursor is synthesized in an aqueous solution on the phosphor particles, and a product produced by hydrothermal synthesis, spray synthesis, or hydrolysis using the phosphor is used. It is manufactured as follows. The synthesis method is a synthesis method and a crystal growth method for obtaining phosphor particles having a nearly spherical shape.
[0056]
(1) Blue phosphor
Ca_1-xMgSi₂O₆: Eu_xWill be described.
[0057]
First, in the mixed liquid preparation step, barium nitrate Ca (NO which is a raw material)_Three)₂, Magnesium nitrate Mg (NO_Three)_Three, Silicon oxide SiO₂(Colloidal silica), Europium nitrate Eu (NO_Three)₂Are mixed so that the molar ratio is 1-X: 1: 2: X (0.03 ≦ X ≦ 0.20), and this is dissolved in an aqueous medium to prepare a mixed solution. In this aqueous medium, ion-exchanged water and pure water are preferable in that they do not contain impurities, but they can be used even if they contain a non-aqueous solvent (such as methanol or ethanol).
[0058]
Next, an alkaline (basic) solution (for example, potassium hydroxide) is added to the hydrated mixed solution to form a spherical hydrate (precursor), which has corrosion resistance and heat resistance such as gold or platinum. For example, using a device that can be heated while being pressurized, such as an autoclave, in a container made of an object, in a high-pressure container under a predetermined temperature (100 ° C. to 300 ° C.) and a predetermined pressure (0.2 MPa to 10 MPa) In the case of blue, aluminum or graphite powder is added as a reducing agent and hydrothermal synthesis (12 to 20 hours) is performed to produce a spherical precursor.
[0059]
Here, the hydration mixture is sprayed into a furnace heated to 1000 ° C. to 1500 ° C. while applying ultrasonic waves directly from a pressure nozzle without using an autoclave, thereby producing a spherical precursor. The method may be used.
[0060]
Next, these precursor powders are fired in a reducing atmosphere (for example, an atmosphere containing 5% hydrogen and 95% nitrogen) at a predetermined temperature for a predetermined time, for example, 800 ° C. to 1400 ° C. for 2 hours, By classifying this, the desired blue phosphor Ca_1-xMgSi₂O₆: Eu_xCan be obtained.
[0061]
The phosphor particles obtained by hydrothermal synthesis or spray synthesis have a substantially spherical shape and an average particle size of 0.05 μm to 3 μm compared to those prepared from a conventional solid phase reaction. As small as about 0.0 μm is formed. The term “spherical” used herein is defined so that the axial diameter ratio (short axis diameter / major axis diameter) of most fluorescent particles is, for example, 0.9 or more and 1.0 or less. However, not all of the phosphor particles need be within this range.
[0062]
Next, (Sr, Ca)_1-xMgSi₂O₆: Eu_xWill be described.
[0063]
This phosphor is composed of the Ca described above._1-xMgSi₂O₆: Eu_xAnd the raw material is only a part of Ca replaced with Sr (Sr / Ca ratio of 0.1 / 1/0 to 1). Hereinafter, the raw materials used will be described.
[0064]
As raw material, strontium nitrate Sr (NO_Three)₂, Magnesium nitrate Mg (NO_Three)_Three, Silicon oxide SiO₂(Colloidal silica), Europium nitrate Eu (NO_Three)₂Is mixed with water so that the molar ratio is 1-X: 1: 2: X (0.03 ≦ X ≦ 0.20), then this and the basic (alkaline) solution are placed in a container, While applying sound waves to the container, O₂Or O_ThreeWere mixed while bubbling to produce a spherical hydrate (precursor hydrate), and then the hydrate was calcined in air at 800 ° C. to 1450 ° C. and then in a reducing atmosphere at 1000 ° C. to It is produced by a synthesis method in an aqueous solution that is baked at 1400 ° C., and then classified to obtain a blue phosphor.
[0065]
Next, (Ca, Ba)_1-xMgSi₂O₆: Eu_xOther manufacturing methods will be described.
[0066]
As raw material, calcium alkoxide Ca (O ・ R)₂, Barium alkoxide Ba (O ・ R)₂, [(Ca / Ba ratio) 0/1 / 0.1-1], silicon alkoxide Si (O · R)_Four, Europium alkoxide Eu (OR)_Three, Where R is an alkyl group, the molar ratio is 1-X: 1: 2: X (0.03<X<0.2), and the spherical precursor hydrolyzed by adding water or alcohol was calcined at 1000 ° C. to 1400 ° C., and then this was reduced in a reducing atmosphere, for example, 5% hydrogen, A blue phosphor can also be obtained by a hydrolysis method in which nitrogen is baked in a 95% atmosphere at a predetermined temperature (1000 ° C. to 1400 ° C. for 2 hours) and then classified by an air classifier.
[0067]
Next, Ba_{3 (1-x)}MgSi₂O₈: Eu_xWill be described.
[0068]
First, barium nitrate Ba (NO, which is a raw material in the mixed liquid preparation step)_Three)₂, Magnesium nitrate Mg (NO_Three)_Three, Silicon oxide SiO₂(Colloidal silica), Europium nitrate Eu (NO_Three)₂Are mixed so that the molar ratio is 3 (1-X): 1: 2: X (0.003 ≦ X ≦ 0.20), and this is dissolved in an aqueous medium to prepare a mixed solution. In this aqueous medium, ion-exchanged water and pure water are preferable in that they do not contain impurities, but they can be used even if they contain a non-aqueous solvent (such as methanol or ethanol).
[0069]
Next, an alkaline (basic) solution (for example, potassium hydroxide) is added to the hydrated mixture to form a spherical hydrate (precursor), which has corrosion resistance and heat resistance such as gold or platinum. For example, using a device that can be heated while being pressurized, such as an autoclave, the container is made of blue under a predetermined temperature (100 ° C. to 300 ° C.) and a predetermined pressure (0.2 MPa to 10 MPa) in a high pressure vessel. In this case, aluminum or graphite powder is added as a reducing agent, and hydrothermal synthesis (12 to 20 hours) is performed to produce a spherical precursor.
[0070]
Here, the hydration mixture is sprayed into a furnace heated to 1000 ° C. to 1500 ° C. while applying ultrasonic waves directly from a pressure nozzle without using an autoclave, thereby producing a spherical precursor. The method may be used.
[0071]
Next, these precursor powders are fired in a reducing atmosphere (for example, an atmosphere containing 5% hydrogen and 95% nitrogen) at a predetermined temperature for a predetermined time, for example, 800 ° C. to 1400 ° C. for 2 hours, By classifying this, the desired blue phosphor Ba_{3 (1-x)}MgSi₂O_Three: Eu can be obtained.
[0072]
The phosphor particles obtained by hydrothermal synthesis or spray synthesis have a substantially spherical shape and an average particle size of 0.05 μm to 3 μm compared to those prepared from a conventional solid phase reaction. As small as about 0.0 μm is formed. The term “spherical” used herein is defined so that the axial diameter ratio (short axis diameter / major axis diameter) of most fluorescent particles is, for example, 0.9 or more and 1.0 or less. However, not all of the phosphor particles need be within this range.
[0073]
Next, (Ba, Sr)_{3 (1-x)}MgSi₂O₈: Eu_xWill be described.
[0074]
This phosphor is the Ba described above._{3 (1-x)}MgSi₂O₈: Eu_xAnd the raw material is only a part of Ba replaced with Sr (Ba / Sr ratio of 0.1 / 1/0 to 1). Hereinafter, the raw materials used will be described.
[0075]
As raw material, strontium nitrate Sr (NO_Three)₂, Barium nitrate Ba (NO_Three)₂, Magnesium nitrate Mg (NO_Three)_Three, Silicon oxide SiO₂(Colloidal silica), Europium nitrate Eu (NO_Three)₂Is mixed with water so that the molar ratio is 3 (1-X): 1: 2: X (0.003 ≦ X ≦ 0.20), and then this is put into a container with a basic (alkaline) solution. While applying ultrasonic waves to the container,₂Or O_ThreeWere mixed while bubbling to produce a spherical hydrate (precursor hydrate), and then the hydrate was calcined in air at 800 ° C. to 1450 ° C. and then in a reducing atmosphere at 1000 ° C. to It is produced by a synthesis method in an aqueous solution that is baked at 1400 ° C., and then classified to obtain a blue phosphor.
[0076]
Next, (Ca, Ba)_{3 (1-x)}MgSi₂O₈: Eu_xOther manufacturing methods will be described.
[0077]
As raw material, calcium alkoxide Ca (O ・ R)₂, Barium alkoxide Ba (O ・ R)₂, [(Ca / Ba ratio) 0/1 / 0.1-1], silicon alkoxide Si (O · R)_Four, Europium alkoxide Eu (OR)_Three, Where R is an alkyl group, the molar ratio is 3 (1-X): 1: 2: X (0.003<X<0.2), and the spherical precursor hydrolyzed by adding water or alcohol was calcined at 1000 ° C. to 1400 ° C., and then this was reduced in a reducing atmosphere, for example, 5% hydrogen, A blue phosphor can also be obtained by a hydrolysis method in which nitrogen is baked in a 95% atmosphere at a predetermined temperature (1000 ° C. to 1400 ° C. for 2 hours) and then classified by an air classifier.
[0078]
(2) Green phosphor
Zn_{2 (1-x)}SiO_Four: Mn_xWill be described.
[0079]
First, in the mixed liquid preparation step, zinc nitrate Zn (NO, which is a raw material)_Three), Colloidal silica SiO₂, Manganese nitrate Mn (NO_Three)₂In a molar ratio of 2-X: 1: X (0.01 ≦ X ≦ 0.10) and dissolved in ion-exchanged water to prepare a mixed solution. Next, in the hydration step, a basic aqueous solution (for example, an aqueous ammonia solution) is added to this mixed solution to prepare a hydrate.
[0080]
Thereafter, in the hydrothermal synthesis step, the hydrate and ion-exchanged water are placed in a capsule made of corrosion-resistant or heat-resistant material such as platinum or gold, and are used at a predetermined temperature in a high-pressure vessel using an autoclave, for example. Hydrothermal synthesis is performed for a predetermined time, for example, 2 to 10 hours, under pressure, for example, a temperature of 100 ° C. to 300 ° C. and a pressure of 0.2 MPa to 10 MPa. Then, by drying the particles subjected to hydrothermal synthesis, desired Zn_2-xSiO_Four: Mn_xIs obtained. The phosphor particles obtained by this hydrothermal synthesis step have a particle size of about 0.1 μm to 2.0 μm and a spherical shape. Next, this powder is annealed in air at 800 ° C. to 1100 ° C. to obtain a green phosphor powder.
[0081]
Next, Ba_1-xAl₁₂O₁₉: Mn_xWill be described.
[0082]
First, in the mixed liquid preparation process, the raw material, barium nitrate Ba (NO_Three)₂, Aluminum nitrate Al (NO_Three)₂, Manganese nitrate Mn (NO_Three)₂Are mixed so that the molar ratio is 1-X: 12: X (0.01 ≦ X ≦ 0.10), and this is dissolved in ion-exchanged water to prepare a mixed solution.
[0083]
Next, in the hydration step, a basic aqueous solution, for example, an aqueous ammonia solution is dropped into this mixed solution to form a hydrate. Thereafter, in the hydrothermal synthesis step, the hydrate and ion-exchanged water are placed in a capsule made of a material having corrosion resistance and heat resistance, such as platinum or gold, and predetermined at a predetermined temperature in a high-pressure vessel using an autoclave, for example. Hydrothermal synthesis is performed for a predetermined time, for example, 2 to 20 hours, under pressure, for example, a temperature of 100 ° C. to 300 ° C. and a pressure of 0.2 MPa to 10 MPa.
[0084]
Then, by drying, the desired Ba_1-xAl₁₂O₁₉: Mn_xIs obtained. By this hydrothermal synthesis step, the phosphor obtained has a particle size of about 0.1 μm to 2.0 μm and a spherical shape. Next, this powder is annealed in air at 800 ° C. to 1100 ° C. and then classified to obtain a green phosphor.
[0085]
(3) Red phosphor
(Y, Gd)_1-xBO_Three: Eu_xWill be described.
[0086]
Yttrium hydroxide Y, which is a raw material in the mixed liquid preparation process₂(OH)_ThreeAnd gadolinium hydroxide Gd₂(OH)_ThreeAnd boric acid H_ThreeBO_ThreeAnd europium hydroxide Eu₂(OH)_ThreeAre mixed in ion-exchanged water so that the molar ratio is 1-X: 2: X (0.05 ≦ X ≦ 0.20) (the ratio of Y and Gd is 65:35). Make it. Next, in the hydration step, a basic aqueous solution (for example, an aqueous ammonia solution) is added to the mixed solution to form a hydrate.
[0087]
Thereafter, in the hydrothermal synthesis process, the hydrate and ion-exchanged water are placed in a container having corrosion resistance and heat resistance such as platinum or gold, and for example at a predetermined temperature in a high pressure container using an autoclave for a predetermined time. For example, hydrothermal synthesis is performed for a predetermined time, for example, 3 to 12 hours, under conditions of a temperature of 100 ° C. to 300 ° C. and a pressure of 0.2 MPa to 10 MPa. By this hydrothermal synthesis step, the phosphor obtained has a particle size of about 0.1 μm to 2.0 μm and a spherical shape. Next, this is heat-treated in the air at 800 ° C. to 1200 ° C. for 2 hours and then classified to obtain a red phosphor.
[0088]
Next, Y_2-xO_Three: Eu_xWill be described.
[0089]
Yttrium nitrate Y, which is a raw material in the mixed liquid preparation process₂(NO_Three)₂And europium nitrate Eu (NO_Three)₂Are mixed in ion-exchanged water so as to have a molar ratio of 2-X: X (0.05 ≦ X ≦ 0.30) to prepare a mixed solution. Next, in the hydration step, a basic aqueous solution (for example, an aqueous ammonia solution) is added to this aqueous solution to form a hydrate.
[0090]
Thereafter, in the hydrothermal synthesis step, the hydrate and ion-exchanged water are placed in a container having corrosion resistance and heat resistance such as platinum or gold, and the temperature is set to 100 ° C. to 300 ° C. in a high pressure container using, for example, an autoclave. Hydrothermal synthesis is performed for 3 to 12 hours under the conditions of ° C and pressure of 0.2 MPa to 10 MPa. Thereafter, the obtained compound is dried to obtain the desired Y_2-xO_Three: Eu_xIs obtained.
[0091]
Next, this phosphor is annealed in air at 800 ° C. to 1200 ° C. for 2 hours and then classified to obtain a red phosphor. The phosphor obtained by this hydrothermal synthesis step has a particle size of about 0.1 μm to 2.0 μm and a spherical shape. The particle size and shape are suitable for forming a phosphor layer having excellent light emission characteristics.
[0092]
Each of the above phosphor particles is produced by a hydrothermal synthesis method, a spray synthesis method, and a hydrolysis method using a spherical precursor synthesized in an aqueous solution. It is formed into small particles (average particle size is about 0.1 μm to 2.0 μm). Therefore, oxygen defects are not formed on the surface of the phosphor particles obtained by these synthesis methods, and the luminance and luminance degradation of the phosphor are remarkably improved. In addition, the region where the ultraviolet rays reach in the phosphor particles is as shallow as about several hundred nm from the particle surface, and only the surface emits light. If the particle size of such phosphor particles is 2.0 μm or less, it contributes to light emission. Since the surface area of the particles to be increased increases, the luminance is kept high when the phosphor layer is formed.
[0093]
In addition, the phosphor particles produced by the synthesis of these particles grow in a spherical shape, so that defects such as oxygen defects are reduced. For this reason, ultraviolet rays absorbed by oxygen vacancies are reduced, and excitation of the emission center is likely to occur. In addition, since the phosphor has a spherical shape, the particles are less likely to stick to each other even when fired at a high temperature. Therefore, the phosphor particles can be easily pulverized, have few defects, increase in luminance, and suppress luminance degradation derived from oxygen defects. In addition, since the phosphor of the present invention has a particle size of up to submicron order, coating unevenness when the phosphor is applied is reduced, and the degree of filling of the phosphor in the phosphor layer is improved. The brightness of the PDP is also higher than before.
[0094]
Note that phosphor particles obtained by hydrothermal synthesis of all the phosphor layers were used for the R and G phosphor layers of the PDP described above. However, water can also be produced by an aqueous synthesis method or a spray synthesis method. It is possible to produce R and G phosphor layers substantially equivalent to the thermal synthesis method.
[0095]
Of the three colors R, G, B, especially the conventional CaMgSi₂O₆: The blue phosphor having the Eu structure had lower luminance than the other phosphors, and the luminance was greatly deteriorated by discharge. Therefore, the color temperature of white when the three colors emitted simultaneously tended to decrease. For this reason, in the PDP, the color temperature of white display is improved by reducing the luminance of cells of phosphors other than blue (red, green) in terms of circuit, but the MeMgSi manufactured according to the present invention.₂O₆: Eu or Me_ThreeMgSi₂O₈: If a blue phosphor having a crystal structure of Eu (Me is one or more of Ca, Sr, and Ba) is used, the luminance of blue cells is increased and the luminance of cells of other colors is intentionally decreased. Is no longer necessary. Therefore, it is not necessary to intentionally lower the brightness of all the color cells, and the brightness of all the color cells can be fully used. Therefore, while maintaining a high color temperature for white display, Brightness can be increased. The blue phosphor according to the present invention can also be applied to fluorescent lamps that are excited and emitted by the same ultraviolet rays. In that case, the conventional blue phosphor portion applied to the inner wall of the fluorescent tube may be replaced with a phosphor portion made of a blue phosphor obtained by an aqueous synthesis method, a hydrothermal synthesis method or a spray synthesis method. . As described above, when the phosphor according to the present invention is applied to a fluorescent lamp, it is possible to obtain a lamp that is superior in luminance and luminance degradation than a conventional fluorescent lamp.
[0096]
(Evaluation Experiment 1)
Hereinafter, in order to evaluate the performance of the plasma display device of the present invention, a sample based on the above embodiment is manufactured, a performance evaluation experiment is performed on the sample, and the experimental result is examined.
[0097]
The produced plasma display device has a size of 42 inches (HD-TV specification with a rib pitch of 150 μm), the thickness of the dielectric glass layer is 20 μm, the thickness of the MgO protective layer is 0.5 μm, and between the display electrode and the display scan electrode The PDP was produced so that the distance of 0.08 mm. The discharge gas sealed in the discharge space is a gas in which 5% xenon gas is mixed mainly with neon, and is sealed at a predetermined discharge gas pressure, for example, 73 kPa.
[0098]
For each phosphor particle used in the PDPs of Samples 1 to 9, spherical precursors prepared in an aqueous solution, a spherical precursor prepared by an aqueous solution synthesis method, a hydrothermal synthesis method, a spray synthesis method, and a hydrolysis method are used. Each phosphor was prepared using the precursors. The respective synthesis conditions are shown in Table 1.
[0099]
[Table 1]

[0100]
Samples 1-4 are red phosphor (Y, Gd)_1-xBO_Three: Eu_x, Green phosphor (Zn_2-xSiO_Four: Mn_x), Blue phosphor [Me_1-xMgSi₂O₆: Eu_x(Me is a combination of Ca, Sr, and Ba)], and a method for producing a phosphor and a substitution ratio of Eu and Mn serving as emission centers, that is, a substitution ratio of Eu with respect to Y and Me elements, Table 1 shows the combinations of Mn substitution ratios and Me with respect to Zn elements.
[0101]
Samples 5 to 9 are red phosphors (Y_2-xO_Three: Eu_x), Green phosphor (Ba_1-xAl₁₂O₁₉: Mn_x), Blue phosphor [Me_1-xMgSi₂O₆: Eu_x(Me is a combination of Ca, Sr, and Ba)], and each phosphor was produced by a hydrothermal synthesis method, a spray synthesis method, and a hydrolysis method in the same manner as described above. Further, the substitution ratio of the light emission center and the combination of Me are changed as shown in Table 1. In addition, the phosphor ink used for forming the phosphor layer is prepared by mixing phosphor, resin, solvent, and dispersant in the mixing ratio as shown in the above example using each phosphor particle shown in Table 1. Produced.
[0102]
Further, samples 10 and 11 are comparative examples, and the red phosphors are (Y, Gd)._1-xBO_Three: Eu₂, Green phosphor (Zn₂SiO_Four: Mn_x) By hydrothermal synthesis, and the blue phosphor is CaMgSi₂O₆: Eu (sample 10) and BaMgAl_TenO₁₇: A combination using Eu (sample 11) prepared by a solid-phase reaction method, and a phosphor layer prepared under the same conditions as in samples 1 to 9 above.
[0103]
As a result of measuring about the viscosity (25 degreeC) of the phosphor ink at that time, as for all, the viscosity is kept in the range of 1500CP-30000CP. When the formed phosphor layer was observed, the phosphor ink was uniformly applied to the partition wall surface. Moreover, about the fluorescent substance particle used for the fluorescent substance layer in each color, a composition and a manufacturing method as shown in Table 1 are used for each sample.
[0104]
Next, the blue phosphor particles of Comparative Samples 10 and 11 are obtained by sieving after phosphor particles subjected to solid phase reaction are pulverized with a ball mill using a conventional sintering process. Was used. For the red phosphor, a spherical Y having a particle diameter of 2.0 μm prepared by the same hydrothermal synthesis method as Sample 9 was used.₂O_Three: Eu (see Table 3) was used, and the film thickness was 20 μm. For the green phosphor, an amorphous Ba having a particle diameter of 2.2 μm, which was also produced by the same hydrothermal synthesis method as Sample 9, was used._1-xAl₁₂O₁₉: Mn_xThe film thickness was 20 μm. For the blue phosphor, CaMgSi produced by the conventional sintering method₂O₆: Eu to H₂-N₂After calcination in gas at 1400 ° C. for 5 hours, the particle diameter obtained was 4.0 μm by grinding and sieving.
[0105]
The phosphor ink used for forming the phosphor layer was prepared by mixing phosphor, resin, solvent and dispersant using each phosphor particle shown in Table 1.
[0106]
With respect to Samples 1 to 9 and Comparative Samples 10 and 11 manufactured in this way, in the process of manufacturing PDP, the luminance deterioration of each phosphor in the phosphor firing in the back panel process (conditions are 520 ° C. and in the air) Rate, luminance degradation rate of the phosphor in the panel sealing process (heating at 450 ° C), luminance degradation rate during accelerated panel life, presence / absence of address miss during address discharge, and luminance when blue all over Measured.
[0107]
The brightness of the PDP was measured in a state where a discharge sustain pulse having a voltage of 150 V and a frequency of 30 kHz was applied to the panel.
[0108]
The rate of change in luminance deterioration is measured by measuring the panel luminance before and after applying a discharge sustain pulse having a voltage of 200 V and a frequency of 100 kHz to the PDP for 100 hours, and from that, the rate of change in luminance deterioration (<[after application] Brightness-luminance before application] / luminance before application> x 100).
[0109]
Further, an address miss at the time of address discharge is determined by checking whether there is flicker by looking at the image, and if there is even one place, it is determined. Regarding the luminance distribution of the panel, the luminance at the time of white display was measured with a luminance meter to show the distribution of the entire surface.
[0110]
Table 2 shows the results of the luminance and the luminance deterioration change rate. In the experiment, the respective color phosphor layers are discharged uniformly, and control for suppressing the luminance of the red and green cells is not performed in order to adjust the color temperature when displaying white.
[0111]
[Table 2]

[0112]
As shown in Table 2, in Comparative Samples 10 and 11, the luminance deterioration change rates during the conventional blue phosphor firing (520 ° C.) were −4.6% and −5.6%, respectively, and panel sealing The luminance deterioration rate in the process (450 ° C.) is −14.5% and −21.8%, respectively, and the luminance change after applying the sustaining pulse for 100 hours is −11.0% and −34.6%, respectively. There is an address discharge error, and the blue luminance of the panel is 61, 46 cd / cm, respectively.²The value of was shown.
[0113]
On the other hand, the blue phosphor Me_1-xMgSi₂O₆: Eu_xFor samples 1 to 9 using a phosphor having a structure, the brightness of the blue all-over spot light is 80 cd / cm across the board.²A value exceeding. Further, the luminance deterioration change rate during phosphor firing (520 ° C.) is −0.2 to −2.8%, and the luminance change rate during panel sealing step (450 ° C.) is −0.3 to −5. At 0%, the luminance change rate after applying the sustaining pulse for 100 hours was -0.2 to -0.9%, and there was no address miss.
[0114]
That is, the product of the present invention exhibits superior characteristics with respect to panel luminance, luminance deterioration in various processes, and address discharge errors, as compared with Comparative Samples 10 and 11.
[0115]
This is because the blue phosphor particles according to the present invention are prepared by using a synthesis method in an aqueous solution, a hydrothermal synthesis method, a spray synthesis method, or a hydrolysis method._1-xMgSi₂O₆: Eu_xA phosphor having a crystal structure (where Me is one or more of Ca, Sr, and Ba) can synthesize relatively small (0.1 μm to 3.0 μm) substantially spherical phosphor particles. Therefore, it is considered that the pulverization of the particles is not required and the generation of oxygen defects is suppressed, and the filling degree of the phosphor particles in the phosphor layer is improved, and the surface of the phosphor particles contributing to light emission is increased. In particular, a panel in which part or all of Ca is replaced with Ca and Ba is improved in luminance and various characteristics as compared with Ca alone.
[0116]
In other words, by suppressing the occurrence of oxygen defects in the blue phosphor particles, it becomes difficult for the crystallinity to decrease starting from the oxygen defects, and particularly the blue color temperature deterioration and luminance deterioration are suppressed, Since the amount of ultraviolet rays absorbed by oxygen vacancies is reduced, it is considered that the luminance is improved as compared with the conventional case because the emission center is easily excited.
[0117]
(Evaluation Experiment 2)
In the evaluation experiment 1, the phosphor according to the present invention was used for the PDP. Similarly, a fluorescent lamp sample using the phosphor according to the present invention was manufactured as a fluorescent lamp that emits light when excited by ultraviolet rays.
[0118]
In a known fluorescent lamp, as a phosphor layer formed on the inner wall of a glass tube, a phosphor layer obtained by applying a mixture of phosphors of each color produced under the conditions of sample 4 shown in Table 1 above is used. Using, a fluorescent lamp sample 12 was produced. As a comparative example, a comparative fluorescent lamp sample 13 coated with a mixture of phosphors of various colors prepared under the conditions of sample 11 (Table 1) that reacts by a conventional solid-phase reaction was similarly prepared.
[0119]
The luminance before and after applying a pulse voltage of 100 V, 60 Hz for 5000 hours was measured for the fluorescent lamp sample 12 and the comparative fluorescent lamp sample 13 of this evaluation experiment 2, and the luminance change rate (<[post-applied Luminance-luminance before application] / luminance before application> x 100). The results are shown in Table 3.
[0120]
[Table 3]

[0121]
From the results shown in Table 3, a spherical precursor was prepared in an aqueous solution, and then Me was prepared by spray synthesis, hydrothermal synthesis, hydrolysis, and the like using the precursor._1-xMgSi₂O₆: Eu_xCompared with the fluorescent lamp sample 13, the fluorescent lamp sample 12 using the blue phosphor particles having the structure is improved in luminance by about 4%, and the luminance change rate is greatly improved.
[0122]
(Evaluation Experiment 3)
Next, Me_{3 (1-x)}MgSi₂O₈: Eu_xIn order to evaluate the performance of the plasma display device using the phosphor having the structure, similarly to the above-described evaluation experiment 1, a sample is produced, and the results of an experiment in which the performance evaluation experiment was performed on the sample are shown in Table 4.
[0123]
[Table 4]

[0124]
Samples 1-4 are red phosphor (Y, Gd)_1-xBO_Three: Eu_x, Green phosphor (Zn_2-xSiO_Four: Mn_x), Blue phosphor [Me_{3 (1-x)}MgSi₂O₈: Eu_x(Me is a combination of Ca, Sr, and Ba)], and a method for producing a phosphor and a substitution ratio of Eu and Mn serving as emission centers, that is, a substitution ratio of Eu with respect to Y and Me elements, Table 4 shows combinations of Mn substitution ratios with respect to Zn elements and combinations of Me.
[0125]
Samples 5 to 9 are red phosphors (Y_2-xO_Three: Eu_x), Green phosphor (Ba_1-xAl₁₂O₁₉: Mn_x), Blue phosphor [[Me_{3 (1-x)}MgSi₂O₈: Eu_x(Me is a combination of Ca, Sr, and Ba)], and similarly to the above, fluorescence produced using a precursor synthesized by a hydrothermal synthesis method, a spray synthesis method, and a hydrolysis method. Is the body. In addition, the substitution ratio of the emission center and the combination of Me are changed as shown in Table 4. In addition, the phosphor ink used for forming the phosphor layer is prepared by mixing phosphor, resin, solvent, and dispersant in the mixing ratio as shown in the above-described example using each phosphor particle shown in Table 4. Produced.
[0126]
Furthermore, samples 10, 11, and 12 are comparative examples, and the red phosphor [[Y_1-x)₂O_Three: Eu₂, Green phosphor (Ba_1-xAl₁₂O₁₉: Mn_x) By hydrothermal synthesis, and the blue phosphor is Ba_ThreeMgSi₂O₈: Eu (sample 10), BaMgAl_TenO₁₇: Eu (sample 11), CaMgSi₂O₆: A combination using Eu (sample 12) prepared by a solid-phase reaction method, and a phosphor layer prepared under the same conditions as in samples 1 to 9 above.
[0127]
As a result of measuring about the viscosity (25 degreeC) of the phosphor ink at that time, as for all, the viscosity is kept in the range of 1500CP-30000CP. When the formed phosphor layer was observed, the phosphor ink was uniformly applied to the partition wall surface. Moreover, about the fluorescent substance particle used for the fluorescent substance layer in each color, a composition and a manufacturing method as shown in Table 4 are used for each sample.
[0128]
Next, the blue phosphor particles of Comparative Samples 10, 11, and 12 are obtained by sieving after phosphor particles subjected to solid phase reaction are pulverized by a ball mill using a conventional sintering process. Used. For the red phosphor, a spherical Y having a particle diameter of 2.0 μm prepared by the same hydrothermal synthesis method as Sample 9 was used.₂O_Three: Eu was used, and the film thickness was 20 μm. For the green phosphor, an amorphous Ba having a particle diameter of 2.2 μm, which was also produced by the same hydrothermal synthesis method as Sample 9, was used._1-xAl₁₂O₁₉: Mn_xThe film thickness was 20 μm. For the blue phosphor, Ba produced by the conventional sintering method is used._ThreeMgSi₂O₈: Eu (sample 10), BaMgAl_TenO₁₇: Eu (sample 11), CaMgSi₂O₆: Eu (sample 12) is H₂-N₂After calcination in gas at 1400 ° C. for 5 hours, the particle diameter obtained was 4.0 μm by grinding and sieving.
[0129]
The phosphor ink used for forming the phosphor layer was prepared by mixing phosphor, resin, solvent and dispersant using each phosphor particle shown in Table 4.
[0130]
For Samples 1 to 9 and Comparative Samples 10, 11, and 12 produced in this way, as in Evaluation Experiment 1, the phosphors were fired in the back panel process (conditions were 520 ° C. in air). Luminance deterioration rate, phosphor luminance deterioration rate in the panel sealing process (heating at 450 ° C), brightness deterioration rate during accelerated panel life, presence / absence of address miss during address discharge, and luminance when blue all over Etc. were measured.
[0131]
Table 5 shows the results of the luminance and the luminance deterioration change rate. In the experiment, the respective color phosphor layers are discharged uniformly, and control for suppressing the luminance of the red and green cells is not performed in order to adjust the color temperature when displaying white.
[0132]
[Table 5]

[0133]
As shown in Table 5, in Comparative Samples 10, 11, and 12, when the conventional blue phosphor was fired (520 ° C.), the luminance deterioration change rates were −3.6%, −5.6%, and −, respectively. The deterioration rate of luminance in the panel sealing process (450 ° C.) is 4.6%, −12.5%, −21.8%, and −14.5%, respectively. -10.5%, -34.6% and -11.0%, respectively, address discharge error, and the blue brightness of the panel is 65, 46 and 61 cd / cm, respectively.²The value of was shown.
[0134]
On the other hand, the blue phosphor Me_{3 (1-x)}MgSi₂O₈: Eu_xFor samples 1 to 9 using the phosphors of the structure, the brightness of the blue all-over light is 83 cd / cm across the board.²A value exceeding. Further, the luminance deterioration change rate at the time of firing the blue phosphor (520 ° C.) is −0.2 to −1.8%, and the luminance change rate at the panel sealing step (450 ° C.) is −0.2 to −3. At 0.0%, the luminance change rate after applying the sustaining pulse for 100 hours was -0.2 to -0.5%, and there was no address miss.
[0135]
That is, the product of the present invention exhibits superior characteristics with respect to panel luminance, luminance deterioration in various processes, and address discharge mistakes, as compared with the comparative samples 10, 11, and 12.
[0136]
This is because the blue phosphor particles according to the present invention were prepared from a precursor synthesized using an aqueous solution synthesis method, a hydrothermal synthesis method, a spray synthesis method, and a hydrolysis method._{3 (1-x)}MgSi₂O₈: Eu_xA phosphor having a crystal structure (where Me is one or more of Ca, Sr, and Ba) can synthesize relatively small (0.1 μm to 3.0 μm) substantially spherical phosphor particles. Therefore, it is considered that the pulverization of the particles is not required and the generation of oxygen defects is suppressed, and the filling degree of the phosphor particles in the phosphor layer is improved, and the surface of the phosphor particles contributing to light emission is increased. In particular, the brightness and various characteristics are improved in a panel in which a part or all of it is replaced with Ca and Sr rather than Ba alone.
[0137]
In other words, by suppressing the occurrence of oxygen defects in the blue phosphor particles, it becomes difficult for the crystallinity to decrease starting from the oxygen defects, and particularly the blue color temperature deterioration and luminance deterioration are suppressed, Since the amount of ultraviolet rays absorbed by oxygen vacancies is reduced, it is considered that the luminance is improved as compared with the conventional case because the emission center is easily excited.
[0138]
(Evaluation Experiment 4)
About the fluorescent substance of the said evaluation experiment 3, the fluorescent lamp sample used for the fluorescent lamp which similarly light-emits by being excited by an ultraviolet-ray was produced. As in Evaluation Experiment 2, in a known fluorescent lamp, a phosphor layer formed on the inner wall of the glass tube is coated with a mixture of phosphors of each color produced under the conditions of Sample 4 shown in Table 4 above. Using the phosphor layer obtained by the above, a fluorescent lamp sample 12 was produced. As a comparative example, a comparative fluorescent lamp sample 13 coated with a mixture of phosphors of various colors prepared under the conditions of sample 11 (Table 4) that reacts by a conventional solid-phase reaction was similarly prepared.
[0139]
The luminance before and after applying a pulse voltage of 100 V, 60 Hz for 5000 hours was measured for the fluorescent lamp sample 12 and the comparative fluorescent lamp sample 13 of this evaluation experiment 4, and the luminance change rate (<[post-applied Luminance-luminance before application] / luminance before application> × 100). The results are shown in Table 6.
[0140]
[Table 6]

[0141]
From the results shown in Table 6, a spherical precursor was prepared in an aqueous solution, and then used to produce a Me that was prepared by spray synthesis, hydrothermal synthesis, hydrolysis, or the like._{3 (1-x)}MgSi₂O₈: Eu_xCompared with the fluorescent lamp sample 13, the fluorescent lamp sample 12 using the blue phosphor particles having the structure is improved in luminance by about 4%, and the luminance change rate is greatly improved.
[0142]
【The invention's effect】
As described above, according to the present invention, Me produced by an aqueous solution synthesis method, a hydrothermal synthesis method, or a spray synthesis method is used._1-xMgSi₂O₆: Eu_xStructure or Me_{3 (1-x)}MgSi₂O₈: Eu_xBy forming the phosphor layer with blue phosphor particles having a structure (Me is one or more of Ca, Sr and Ba), the efficiency of absorbing the ultraviolet rays of the phosphor layer is improved, and the plasma display Luminance, lifetime and reliability of lighting devices such as devices and lamps can be improved.
[Brief description of the drawings]
FIG. 1 is a plan view showing a state in which a front glass substrate of a plasma display panel according to an embodiment of the present invention is removed.
FIG. 2 is a perspective view showing the structure of the image display area.
FIG. 3 is a block diagram of a plasma display device according to an embodiment of the present invention.
FIG. 4 is a sectional view showing the structure of the image display area of the plasma display panel.
FIG. 5 is a schematic configuration diagram of an ink coating apparatus used when forming a phosphor layer in the present invention.
[Explanation of symbols]
100 PDP
101 Front glass substrate
103 Display electrode
104 Display scan electrode
105 Dielectric glass layer
106 MgO protective layer
107 Address electrode
108 Dielectric glass layer
109 Bulkhead
110 phosphor layer

Claims (5)

A plasma display comprising a plasma display panel in which a plurality of discharge cells of one color or a plurality of colors are arranged, a phosphor layer of a color corresponding to each discharge cell is disposed, and the phosphor layer is excited by ultraviolet rays to emit light The blue phosphor in the phosphor layer is MeMgSi ₂ O ₆ : Eu or Me ₃ MgSi ₂ O ₈ : Eu (where Me is prepared using a precursor synthesized in an aqueous solution). Is composed of a phosphor having a crystal structure of any one of Ca, Sr, and Ba), having an average particle size of 0.1 μm to 3.0 μm and a maximum particle size of 8 μm or less. A plasma display device. A plasma display comprising a plasma display panel in which a plurality of discharge cells of one color or a plurality of colors are arranged, a phosphor layer of a color corresponding to each discharge cell is disposed, and the phosphor layer is excited by ultraviolet rays to emit light The blue phosphor in the phosphor layer is Me ₃ MgSi ₂ O ₈ synthesized by a hydrothermal synthesis method at a temperature of 100 ° C. to 300 ° C. and a pressure of 0.2 MPa to 10 MPa : It is composed of a phosphor having a crystal structure of Eu (where Me is one or more of Ca, Sr, and Ba) , its average particle size is 0.1 μm to 3.0 μm, and its film thickness is 3 μm to 20 μm. A plasma display device characterized by that. A method for producing a blue phosphor that emits visible light when excited by ultraviolet light, wherein the blue phosphor is made of MeMgSi ₂ O ₆ : Eu (where Me is one or more of Ca, Sr, and Ba). A mixed solution preparation step of preparing a mixed solution by mixing a raw material and an aqueous medium, and applying the mixed solution and a basic aqueous solution to a vibrating container with ultrasonic waves to generate oxygen or ozone. A precursor forming step of forming a hydrate by mixing while bubbling, a step of drying the hydrate in air at 800 ° C. to 1250 ° C., and 1000 ° C. to 1400 ° C. in a reducing atmosphere. And a step of firing. A method of manufacturing a phosphor . A method for producing a blue phosphor that emits visible light when excited by ultraviolet rays, wherein the blue phosphor is Me _Three MgSi ₂ O ₈ : Having a crystal structure composed of Eu (where Me is one or more of Ca, Sr, and Ba), and a mixed liquid preparing step of preparing a mixed liquid by mixing a raw material and an aqueous medium; A precursor forming step of forming a hydrate by applying a mixed solution and a basic aqueous solution ultrasonically to a vibrating vessel and mixing while bubbling oxygen or ozone, and after drying the hydrate in air A method for producing a phosphor, comprising a step of firing at 800 ° C. to 1450 ° C. and a step of firing at 1000 ° C. to 1400 ° C. in a reducing atmosphere. A method for producing a blue phosphor that emits visible light when excited by ultraviolet rays, wherein the blue phosphor is Me _Three MgSi ₂ O ₈ : A mixed liquid preparation step in which a mixed liquid is prepared by mixing a raw material and an aqueous medium, and having a crystal structure composed of Eu (where Me is one or more of Ca, Sr, and Ba), and the mixing The temperature during hydrothermal synthesis is 100 ° C. to 300 ° C. for a hydration step in which a hydrate is formed by mixing a liquid and a basic aqueous solution, and a solution in which the hydrate and water are mixed. And a hydrothermal synthesis step of performing a hydrothermal synthesis reaction in a state where the pressure is 0.2 MPa to 10 MPa.

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