JP4045662B2 - Heat resistant glass composition and plasma display panel using the same - Google Patents
Heat resistant glass composition and plasma display panel using the same Download PDFInfo
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- JP4045662B2 JP4045662B2 JP23697198A JP23697198A JP4045662B2 JP 4045662 B2 JP4045662 B2 JP 4045662B2 JP 23697198 A JP23697198 A JP 23697198A JP 23697198 A JP23697198 A JP 23697198A JP 4045662 B2 JP4045662 B2 JP 4045662B2
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- C—CHEMISTRY; METALLURGY
- C03—GLASS; MINERAL OR SLAG WOOL
- C03C—CHEMICAL COMPOSITION OF GLASSES, GLAZES OR VITREOUS ENAMELS; SURFACE TREATMENT OF GLASS; SURFACE TREATMENT OF FIBRES OR FILAMENTS MADE FROM GLASS, MINERALS OR SLAGS; JOINING GLASS TO GLASS OR OTHER MATERIALS
- C03C3/00—Glass compositions
- C03C3/04—Glass compositions containing silica
- C03C3/076—Glass compositions containing silica with 40% to 90% silica, by weight
- C03C3/083—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound
- C03C3/085—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal
- C03C3/087—Glass compositions containing silica with 40% to 90% silica, by weight containing aluminium oxide or an iron compound containing an oxide of a divalent metal containing calcium oxide, e.g. common sheet or container glass
Description
【０００１】
【発明の属する技術分野】
本発明は、建築用の窓ガラスとして用いられるソーダライムシリカ組成のガラスと同程度の膨張率と、そのガラスが有する転移点より高い転移点を有する耐熱性のガラス組成物に関し、液晶ディスプレイパネル、エレクトロルミネッセンスディスプレイパネル、プラズマディスプレイパネル（以下ＰＤＰという）、フィールドエミッションディスプレイパネルおよび蛍光表示管等の表示装置等のガラス基板、特にＰＤＰ用の基板として好適に用いられるガラス組成物に関する。
【０００２】
【従来の技術】
表示装置に用いられるガラス基板の組成は、表示装置の形式に応じて種々の組成物が開示されている。ＰＤＰは大面積で直視型の壁掛けハイビジョンＴＶ用表示装置として注目されており、ＰＤＰ用のガラス基板は、従来一般建築用のソーダライムシリカ組成のガラス板が用いられてきた。ＰＤＰの製造工程では、ガラス基板上への電極の焼き付け、誘電体の形成、隔壁の形成および蛍光体の形成等を行う工程で、５００〜６００℃の範囲の高温の熱処理がなされる。
【０００３】
これらの熱処理工程で発生するガラス基板の熱収縮は、次工程で表示のパターンを合わせる際、また表側のガラス基板と裏側のガラス基板とを張り合わせる際の位置ずれの原因となる。このため、大型もしくは高精細のＰＤＰを製造するには、ガラス基板の熱収縮率の値、およびそのばらつきを管理することが必要である。さらに上記の熱処理には、絶縁ペースト、シーリングフリット等が用いられるので、ガラス基板はこれらと熱膨張率がマッチングすることが要求される。このため、ガラス基板の５０〜３５０℃の平均熱膨張率は、７５〜９５×１０-7／℃程度、好ましくは８０〜９０×１０-7／℃が要求される。熱処理によるガラスの寸法の収縮を小さくするには、転移点の高いガラスを使用する必要がある。
【０００４】
液晶表示装置に用いられる無アルカリガラス基板は、高い転移点を有するが膨張率が小さいため、ＰＤＰの用途には適さない。一方、従来用いられてきた上記ソーダライムシリカ組成のガラスは、大面積のガラス板を大量安価に製造できるフロート法（溶解ガラスを錫浴上に流し込んで板状に成形する方法）で製造されており、膨張率の値はＰＤＰ用の要求を満たすが、転移点は５５０℃程度であり、５００〜６００℃の熱処理を行うと大きな熱収縮を生じ、大型もしくは高精細のＰＤＰには必ずしも適しているとは言えない。ガラス転移点がＰＤＰ製造時の熱処理温度よりも５０℃以上高いことは、熱変形が起こりにくいからである。
【０００５】
上記の問題点を解決するために、特開平９−２５５３５５号公報、特開平９−２５５３５６号公報、特開平９−３０１７３２号公報および特開平９−３０１７３３号公報には、転移点が６６０℃以上で膨張率がＰＤＰの用途に適したガラス組成物が開示されている。
【０００６】
特開平９−２５５３５５号公報や特開平９−２５５３５６号公報に開示されているガラスは、ＳｉＯ2が少なくアルカリ土類酸化物が多いため、失透温度が作業温度よりもかなり高くフロート法による成形が難しく、かつ、比重が３．０を越えているためＰＤＰ用基板としては実用的ではない。また、特開平９−３０１７３２号公報や特開平９−３０１７３３号公報に開示のガラスは比重が軽く、失透温度は転移点より低いものの、溶融温度が１７００℃に近く、作業温度が１２００℃以上であるため、フロート法で溶融、成形するのは困難である。
【０００７】
【発明が解決しようとする課題】
本発明は、上記のガラス組成物が有する問題点を解決するために得られたものであり、フロート法による溶融、成形に適しかつ、とりわけＰＤＰ用に適した耐熱性と膨張率を有するガラス組成物を得ることを課題とする。
【０００８】
【課題を解決するための手段】
請求項１は、重量％で表示して下記の組成であり、
ＳｉＯ2：５０〜５４．９
Ａｌ2Ｏ3：１０．５〜１８
ＺｒＯ2：１〜６
Ｂ2Ｏ3：０〜３
Ｌｉ2Ｏ：０〜１
Ｎａ2Ｏ：０〜１０
Ｋ2Ｏ：０〜１５
ＭｇＯ：０〜８
ＣａＯ：４〜８
ＳｒＯ：０〜４
ＢａＯ：３〜１２
ＴｉＯ2：０〜３
ＺｎＯ：０〜２
ＳＯ3＋Ｓｂ2Ｏ3：０〜１
ＳｉＯ2＋Ａｌ2Ｏ3＋ＺｒＯ2：７０．１以上
Ｌｉ2Ｏ＋ＮａaＯ＋Ｋ2Ｏ：６〜１９
ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯ：１０〜１９
かつ、５０〜３５０℃の平均膨張率が７５〜９５×１０-7／℃、転移点が６５０℃以上である耐熱性ガラス組成物である。
【０００９】
請求項２は、請求項１において、ガラスの溶融温度が１６００℃以下、失透温度が１１３５℃以下、失透温度が作業温度よりも低いことを特徴とする。
【００１０】
請求項３は、請求項１または２において、重量％で表示して下記の組成であり、
ＳｉＯ2：５２．５〜５４．５
Ａｌ2Ｏ3：１１．０〜１５
ＺｒＯ2：２．５〜５．５
Ｂ2Ｏ3：０〜２
Ｌｉ2Ｏ：０〜０．５
Ｎａ2Ｏ：４〜７
Ｋ2Ｏ：４〜１０
ＭｇＯ：０〜６
ＣａＯ：４〜７
ＳｒＯ：０〜４
ＢａＯ：４〜９
ＴｉＯ2：０〜１
ＺｎＯ：０〜１
ＳＯ3＋Ｓｂ2Ｏ3：０〜１
ＳｉＯ2＋Ａｌ2Ｏ3＋ＺｒＯ2：７０．５以上
Ｌｉ2Ｏ＋Ｎａ2Ｏ＋Ｋ2Ｏ：９〜１５
ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯ：１２〜１９
かつ、５０〜３５０℃の平均膨張率が８０〜９０×１０-7／℃、転移点が６６０℃以上であることを特徴とする。
【００１１】
請求項４は、請求項１〜３のいずれかにおいて、比重を２．７５以下としたことを特徴としている。
【００１２】
【発明の実施の形態】
本発明における組成限定理由は以下の通りである。
ＳｉＯ2：
ＳｉＯ2はガラスのネットワークフォーマーである。５０重量％未満ではガラスの転移点が低くなる。一方、５５重量％以上では熔解性が悪くなりフロート法での成形が困難になる。従って５０〜５４．９重量％、さらには５２．５〜５４．５重量％の範囲が好適に用いられる。
【００１３】
Ａｌ2Ｏ3：
Ａｌ2Ｏ3はガラスの転移点を上げるのに有効な成分である。１０．５重量％未満ではガラスの転移点が低下し、一方１８重量％を越えると失透が起こりやすくなる。従って１０．５〜１８重量％、さらには１１〜１５重量％の範囲が好適に用いられる。
【００１４】
ＺｒＯ2：
ＺｒＯ2はＡｌ2Ｏ3と同様にガラスの転移点を上げるのに有効な成分である。
また、Ａｌ2Ｏ3に比べて失透の発生を抑える作用がある。１重量％未満ではガラスの転移点の向上の効果が見られず、一方６重量％を越えると溶融ガラス中に未溶解成分として残存する。従って１〜６重量％、さらには２．５〜５．５重量％の範囲が好適に用いられる。
【００１５】
ＳｉＯ2＋Ａｌ2Ｏ3＋ＺｒＯ2：
ＳｉＯ2＋Ａｌ2Ｏ3＋ＺｒＯ2の含有量を７０．１重量％以上とすることにより耐候性の向上をはかる。さらには７０．５重量％以上とするのが好ましい。
【００１６】
Ｂ2Ｏ3：
Ｂ2Ｏ3は必須成分ではないが、熔解性向上に有効である。しかし、５重量％を越えると熱膨張率が小さくなる。従って０〜５重量％、さらには０〜２重量％が好適に用いられる。
【００１７】
Ｌｉ2Ｏ：
Ｌｉ2Ｏは必須成分ではないが熔解性向上に有効である。しかし、１重量％を越えるとガラスの転移点が低下しすぎてしまう。また、Ａｌ2Ｏ3との相互作用で失透が起こりやすくなる。従って０〜１重量％、さらには０〜０.５重量％の範囲が好適に用いられる。
【００１８】
Ｎａ2Ｏ：
Ｎａ2Ｏは必須成分ではないが熔解性向上に有効なだけでなく、膨張率を増加させるのにも有効である。さらにＫ2Ｏとの相互作用によりガラスの体積抵抗を向上させる。また、Ｌｉ2Ｏとは異なりＡｌ2Ｏ3との相互作用により失透を起こし易くすることはない。しかし、１０重量％を越えると転移点が低下しすぎる。従って０〜１０重量％、さらには４〜７重量％の範囲が好適に用いられる。
【００１９】
Ｋ2Ｏ：
Ｋ2ＯはＮａ2Ｏと同様に必須成分ではないが熔解性向上に有効なだけでなく、膨張率を増加させるのにも有効である。さらにＮａ2Ｏとの相互作用によりガラスの体積抵抗を向上させる。また、Ｌｉ2Ｏとは異なり、Ａｌ2Ｏ3との相互作用により失透を起こし易くすることはない。しかし、１５重量％を越えると転移点が低下しすぎる。従って０〜１５重量％、さらには４〜１０重量％の範囲が好適に用いられる。
【００２０】
Ｌｉ2Ｏ＋Ｎａ2Ｏ＋Ｋ2Ｏ：
Ｌｉ2Ｏ＋Ｎａ2Ｏ＋Ｋ2Ｏは熔解性に関係し、その合計量は特に膨張率を増加させることと関係する。合計量が６重量％未満では、膨張率が小さくなり、失透が起こりやすくなる。一方１９重量％を越えると転移点が低下するか、もしくは失透が起こりやすくなる。従って６〜１９重量％、さらには９〜１５重量％の範囲が好適に用いられる。
【００２１】
ＭｇＯ：
ＭｇＯは必須成分ではないが熔解性向上に有効であるばかりでなく、転移点を上げるのに有効である。しかし、８重量％を越えると失透が起こりやすくなる。従って０〜８重量％、さらには０〜６重量％の範囲が好適に用いられる。
【００２２】
ＣａＯ：
ＣａＯはＭｇＯと同様に熔解性向上に有効であるばかりでなく、転移点を上げるのに有効である。４重量％未満ではその効果が十分ではない。一方、８重量％を越えると失透が起こりやすくなる。従って４〜８重量％、さらには４〜７重量％の範囲が好適に用いられる。
【００２３】
ＳｒＯ：
ＳｒＯは必須成分ではないが熔解性向上に有効であるばかりでなく、転移点を上げるのに有効である。しかし、４重量％を越えると失透が起こりやすくなるとともに比重が大きくなる。従って０〜４重量％の範囲が好適に用いられる。
【００２４】
ＢａＯ：
ＢａＯは熔解性向上に有効である。しかし、３重量％未満ではその効果は十分ではない。一方、１２重量％を越えると比重が大きくなる。従って０〜１２重量％、さらには４〜９重量％の範囲が好適に用いられる。
【００２５】
ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯ：
ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯはガラスの熔解性向上と関係する。合計量で１０重量％未満では所望の熔解性が得られない。一方、１９重量％を越えると失透し易くなる。従って１０〜１９重量％、さらには１２〜１９重量％の範囲が好適に用いられる。
【００２６】
ＴｉＯ2：
ＴｉＯ2は必須成分ではないが化学的耐久性向上に効果がある。３重量％を越えるとガラスが着色するので好ましくない。従って０〜３重量％、さらには０〜１重量％の範囲が好適に用いられる。
【００２７】
ＺｎＯ：
ＺｎＯは必須成分ではないが熔解性向上に有効である。しかし、２重量％を越えると、揮発が大きくガラス溶融炉の寿命を短くする。従って０〜２重量％、さらには０〜１重量％の範囲が好適に用いられる。
【００２８】
ＳＯ3＋Ｓｂ2Ｏ3：
ＳＯ3＋Ｓｂ2Ｏ3は必須成分ではないが清澄剤として用いられる。使用量としては１重量％以下が好ましい。
【００２９】
本発明においては、ガラスの透過率を調整し、ＰＤＰの表示コントラストを上げるために、Ｖ、Ｃｒ、Ｍｎ、Ｆｅ、Ｃｏ、Ｎｉ、Ｃｕ、Ｍｏ、Ｒｕ、Ｃｅ等の酸化物を着色成分として添加しても良い。
【００３０】
ＰＤＰを製造するときに用いるシーリングフリット等の膨張率とマッチングさせるために、５０〜３５０℃の平均膨張率が７５〜９５×１０-7／℃であることが必要である。さらには８０〜９０×１０-7／℃の範囲が好ましい。またＰＤＰの製造工程中の熱処理での熱収縮を許容範囲以下におさえるために、転移点は６５０℃以上が必要であり、６６０℃以上が好ましい。
【００３１】
次に、本発明を実施例と比較例により説明する。
実施例
ガラス成分を表１の目標組成となるようにガラス原料を調合した。このとき清澄剤としてボウ硝を用いた。調合したバッチをルツボに投入し、１６００℃で４時間溶融した後流し出して冷却した。このようにして得られたガラス試料の溶融温度（粘度１０2ポアズの温度）、作業温度（粘度１０4ポアズの温度）、失透温度、膨張率、転移点を測定した。
【００３２】
溶融温度および作業温度の測定は以下のようにした。７０ｃｃの白金ルツボにガラスを入れて１６００℃で溶融して測定サンプルとした。このサンプルを試料引き下げ式高温粘度測定装置にセットして、試料の溶融ガラス中に白金球をつるし、容器ごと試料を引き下げるときに白金球にかかる粘性抵抗を荷重として測定し、各温度での粘度を求めた。９００〜１６００℃の温度範囲で温度と粘度の関係を測定した。
【００３３】
失透温度の測定は以下のようにした。ガラスを粉砕して２８３０μｍのフルイを通り１０００μｍのフルイ上に留まったガラス粒２５ｇを計り取り、幅１２ｍｍ、長さ２００ｍｍ、深さ９ｍｍの白金製ボートに上記ガラス粒を敷き詰め、ボートの長さ方向に適当な温度勾配を持つように温度設定された炉内で２時間保持する。炉から取り出した白金ボートを自然放冷させた後に、白金ボート上のガラスを５０倍の望遠鏡を用いて観察し、失透が発生している最高温度を持って失透温度とした。
【００３４】
膨張率の測定は以下のようにした。直径５ｍｍ、高さ１５ｍｍの円柱状のロッドを作製し、２５℃からガラスの降伏点まで、温度とガラスの伸びの関係を測定し、５０℃から３５０℃の間の膨張率を測定した。
【００３５】
転移点の測定は以下のようにした。膨張率測定時の膨張曲線の最初の屈曲点の前後で接線を引き、２本の接線の交点に相当する温度を転移点とした。
【００３６】
各特性の測定結果を表１に示した。表１から分かるように、実施例１〜実施例６のガラス組成物はいずれも、溶融温度は１６００℃未満であり、作業温度（Ｔw）と失透温度（Ｔl）との関係は、Ｔw−Ｔl≧１５℃である。また、ガラスの転移点は６６０℃以上であり、５０〜３５０℃の平均膨張率は８０〜９０×１０-7／℃であった。すなわちこれらのガラス組成は、ＰＤＰの製造時に用いるシーリングフリット等の膨張率とのマッチングがよく、ＰＤＰ等の表示装置のガラス基板として適していることが判明した。
【００３７】
なお、表１および表２の略号は以下の通りである。
Ｎ.Ｗ.Ｆ（ネットワークフォーマー）＝ＳｉＯ2＋Ａｌ2Ｏ3＋ＺｒＯ2
Ｒ2Ｏ＝Ｌｉ2Ｏ＋Ｎａ2Ｏ＋Ｋ2Ｏ
Ｒ’Ｏ＝ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯ
【００３８】
【表１】
【表２】
比較例
表２に示した比較例１〜比較例４のガラス組成物を実施例と同様の方法で作製し、得られたガラス試料の溶融温度、作業温度、失透温度、転移点、熱膨張率を測定した。各特性は実施例と同じ方法で測定した。比較例１および比較例２のガラスは、それぞれ特開平９−２５５３５５号公報および特開平９−２５５３５６号公報に開示されている組成であり、作業温度に対して失透温度が２００℃以上も高く、失透しやすいガラスであり、フロート法で溶融、成形することが困難なガラスであることが分かった。また、比重が３．０を越えており、軽量化が要求されるＰＤＰ用のガラスとして好ましくないことが分かった。
【００４１】
一方比較例３および比較例４のガラスは、それぞれ特開平９−３０１７３２号公報および特開平９−３０１７３３号公報に開示されている組成で、作業温度に対して失透温度が低く比重も小さいものの、溶融温度が１７００℃近くで、作業温度が１２００℃以上のためフロート法の溶解窯では溶融が困難である。
【００４２】
【発明の効果】
本発明のガラス組成物は転移点が高いので、ＰＤＰ用のガラス基板として用いたとき、ＰＤＰ製造工程で受ける熱処理によって生じるガラスの熱収縮量を小さく抑制できる。このため大型あるいは高精細のＰＤＰの製造に必要なガラスの寸法の熱安定性を確保できる。また本発明のガラス組成物からなるガラス基板は、膨張率の値が所定範囲内であるため、ＰＤＰの製造にすでに用いられてるガラスフリット等の部材との熱的マッチングがよく、気密等で信頼性のあるＰＤＰを製造できる。
【００４３】
さらに、本発明のガラス組成物は、溶融温度、失透温度、作業温度が所定範囲に選ばれているので、フロート法で失透物生成などの溶融欠点を生ずることなく溶融でき、それを板状に成形することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a heat-resistant glass composition having an expansion coefficient comparable to that of a glass of soda lime silica composition used as a window glass for construction, and a transition point higher than the transition point of the glass, a liquid crystal display panel, The present invention relates to a glass composition that is suitably used as a glass substrate for a display device such as an electroluminescence display panel, a plasma display panel (hereinafter referred to as PDP), a field emission display panel, and a fluorescent display tube, particularly as a substrate for PDP.
[0002]
[Prior art]
As the composition of the glass substrate used in the display device, various compositions are disclosed depending on the type of the display device. PDP has attracted attention as a large-area, direct-view type wall-mounted high-definition TV display device, and a glass plate of soda lime silica composition for general construction has been used as a glass substrate for PDP. In the PDP manufacturing process, high-temperature heat treatment in the range of 500 to 600 ° C. is performed in a process of baking electrodes on a glass substrate, forming a dielectric, forming barrier ribs, and forming phosphors.
[0003]
The thermal contraction of the glass substrate generated in these heat treatment steps causes a positional shift when the display pattern is matched in the next step, and when the front side glass substrate and the back side glass substrate are pasted together. For this reason, in order to manufacture a large-sized or high-definition PDP, it is necessary to manage the thermal shrinkage value of the glass substrate and its variation. Furthermore, since an insulating paste, a sealing frit, or the like is used for the above heat treatment, the glass substrate is required to have a thermal expansion coefficient matching with these. For this reason, the average thermal expansion coefficient at 50 to 350 ° C. of the glass substrate is required to be about 75 to 95 × 10 −7 / ° C., preferably 80 to 90 × 10 −7 / ° C. In order to reduce the shrinkage of the glass dimensions due to the heat treatment, it is necessary to use a glass having a high transition point.
[0004]
An alkali-free glass substrate used for a liquid crystal display device has a high transition point but a low expansion coefficient, and is not suitable for PDP applications. On the other hand, the glass of the soda lime silica composition that has been conventionally used is manufactured by a float method (a method in which molten glass is poured into a tin bath and formed into a plate shape) that can manufacture a large area glass plate at a low cost in large quantities. The expansion coefficient satisfies the requirements for PDP, but the transition point is about 550 ° C., and heat treatment at 500 to 600 ° C. causes large thermal shrinkage and is not always suitable for large or high definition PDP. I can't say. This is because the glass transition point is higher by 50 ° C. or more than the heat treatment temperature at the time of manufacturing the PDP, because thermal deformation hardly occurs.
[0005]
In order to solve the above problems, JP-A-9-255355, JP-A-9-255356, JP-A-9-301732, and JP-A-9-301733 have a transition point of 660 ° C. or higher. In addition, a glass composition having an expansion coefficient suitable for applications of PDP is disclosed.
[0006]
Since the glass disclosed in JP-A-9-255355 and JP-A-9-255356 has a small amount of SiO 2 and a large amount of alkaline earth oxide, the devitrification temperature is considerably higher than the working temperature and is formed by the float process. Is difficult and the specific gravity exceeds 3.0, it is not practical as a substrate for PDP. Further, the glass disclosed in JP-A-9-301732 and JP-A-9-301733 has a low specific gravity and a devitrification temperature lower than the transition point, but the melting temperature is close to 1700 ° C and the working temperature is 1200 ° C or higher. Therefore, it is difficult to melt and mold by the float process.
[0007]
[Problems to be solved by the invention]
The present invention has been obtained in order to solve the problems of the glass composition described above, and is suitable for melting and forming by the float process, and particularly has a heat resistance and an expansion coefficient suitable for PDP. The task is to get things.
[0008]
[Means for Solving the Problems]
Claim 1 has the following composition expressed in weight%:
SiO 2: 50~54.9
Al 2 O 3 : 10.5-18
ZrO 2 : 1 to 6
B 2 O 3 : 0 to 3
Li 2 O: 0 to 1
Na 2 O: 0 to 10
K 2 O: 0~15
MgO: 0-8
CaO: 4-8
SrO: 0-4
BaO: 3-12
TiO 2 : 0 to 3
ZnO: 0 to 2
SO 3 + Sb 2 O 3 : 0 to 1
SiO 2 + Al 2 O 3 + ZrO 2 : 70.1 or more Li 2 O + Na a O + K 2 O: 6 to 19
MgO + CaO + SrO + BaO: 10-19
And it is a heat resistant glass composition whose average expansion coefficient of 50-350 degreeC is 75-95 * 10 < -7 > / degreeC, and a transition point is 650 degreeC or more.
[0009]
A second aspect is characterized in that, in the first aspect, the melting temperature of the glass is 1600 ° C. or lower, the devitrification temperature is 1135 ° C. or lower, and the devitrification temperature is lower than the working temperature.
[0010]
Claim 3 is the following composition expressed in weight% in claim 1 or 2,
SiO 2: 52.5~54.5
Al 2 O 3 : 11.0-15
ZrO 2 : 2.5 to 5.5
B 2 O 3 : 0 to 2
Li 2 O: 0 to 0.5
Na 2 O: 4~7
K 2 O: 4 to 10
MgO: 0-6
CaO: 4-7
SrO: 0-4
BaO: 4-9
TiO 2 : 0 to 1
ZnO: 0 to 1
SO 3 + Sb 2 O 3 : 0 to 1
SiO 2 + Al 2 O 3 + ZrO 2 : 70.5 or more Li 2 O + Na 2 O + K 2 O: 9 to 15
MgO + CaO + SrO + BaO: 12-19
And the average expansion coefficient of 50-350 degreeC is 80-90 * 10 < -7 > / degreeC, and a transition point is 660 degreeC or more, It is characterized by the above-mentioned.
[0011]
A fourth aspect is characterized in that in any one of the first to third aspects, the specific gravity is 2.75 or less.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
The reasons for limiting the composition in the present invention are as follows.
SiO 2 :
SiO 2 is a glass network former. If it is less than 50% by weight, the glass transition point becomes low. On the other hand, if it is 55% by weight or more, the meltability becomes poor and it becomes difficult to form by the float process. Therefore, the range of 50 to 54.9% by weight, and further 52.5 to 54.5% by weight is preferably used.
[0013]
Al 2 O 3 :
Al 2 O 3 is an effective component for raising the glass transition point. If it is less than 10.5% by weight, the glass transition point is lowered, whereas if it exceeds 18% by weight, devitrification tends to occur. Therefore, the range of 10.5 to 18% by weight, and further 11 to 15% by weight is preferably used.
[0014]
ZrO 2 :
ZrO 2 is an effective component for raising the transition point of glass like Al 2 O 3 .
Further, an effect of suppressing the occurrence of devitrification as compared with Al 2 O 3. If it is less than 1% by weight, the effect of improving the glass transition point is not observed, whereas if it exceeds 6% by weight, it remains as an undissolved component in the molten glass. Accordingly, a range of 1 to 6% by weight, and further 2.5 to 5.5% by weight is preferably used.
[0015]
SiO 2 + Al 2 O 3 + ZrO 2 :
The weather resistance is improved by setting the content of SiO 2 + Al 2 O 3 + ZrO 2 to 70.1% by weight or more. Furthermore, it is preferable to set it as 70.5 weight% or more.
[0016]
B 2 O 3 :
B 2 O 3 is not an essential component, but is effective for improving meltability. However, if it exceeds 5% by weight, the coefficient of thermal expansion becomes small. Therefore, 0 to 5% by weight, and further 0 to 2% by weight is preferably used.
[0017]
Li 2 O:
Li 2 O is not an essential component but is effective in improving meltability. However, if it exceeds 1% by weight, the transition point of the glass is too low. Further, devitrification is likely to occur due to the interaction with Al 2 O 3 . Therefore, the range of 0 to 1% by weight, and further 0 to 0.5% by weight is preferably used.
[0018]
Na 2 O:
Na 2 O is not an essential component but is effective not only for improving the meltability but also for increasing the expansion coefficient. Furthermore, the volume resistance of glass is improved by interaction with K 2 O. Further, unlike Li 2 O, devitrification is not easily caused by interaction with Al 2 O 3 . However, if it exceeds 10% by weight, the transition point is too low. Therefore, the range of 0 to 10% by weight, and further 4 to 7% by weight is preferably used.
[0019]
K 2 O:
Like Na 2 O, K 2 O is not an essential component but is effective not only for improving the meltability but also for increasing the expansion coefficient. Furthermore, the volume resistance of glass is improved by interaction with Na 2 O. Further, unlike Li 2 O, devitrification is not easily caused by interaction with Al 2 O 3 . However, if it exceeds 15% by weight, the transition point is too low. Accordingly, the range of 0 to 15% by weight, and further 4 to 10% by weight is preferably used.
[0020]
Li 2 O + Na 2 O + K 2 O:
Li 2 O + Na 2 O + K 2 O is related to meltability, and the total amount is particularly related to increasing the expansion rate. When the total amount is less than 6% by weight, the expansion coefficient becomes small, and devitrification easily occurs. On the other hand, if it exceeds 19% by weight, the transition point is lowered or devitrification tends to occur. Therefore, the range of 6 to 19% by weight, further 9 to 15% by weight is preferably used.
[0021]
MgO:
MgO is not an essential component but is effective not only for improving the meltability but also for raising the transition point. However, when it exceeds 8% by weight, devitrification tends to occur. Therefore, a range of 0 to 8% by weight, and further 0 to 6% by weight is preferably used.
[0022]
CaO:
Like MgO, CaO is not only effective for improving meltability, but also effective for raising the transition point. If it is less than 4% by weight, the effect is not sufficient. On the other hand, if it exceeds 8% by weight, devitrification tends to occur. Therefore, the range of 4 to 8% by weight, further 4 to 7% by weight is preferably used.
[0023]
SrO:
Although SrO is not an essential component, it is effective not only for improving the meltability but also for raising the transition point. However, if it exceeds 4% by weight, devitrification tends to occur and the specific gravity increases. Therefore, the range of 0 to 4% by weight is preferably used.
[0024]
BaO:
BaO is effective for improving the meltability. However, the effect is not sufficient if it is less than 3% by weight. On the other hand, if it exceeds 12% by weight, the specific gravity increases. Therefore, the range of 0 to 12% by weight, and further 4 to 9% by weight is preferably used.
[0025]
MgO + CaO + SrO + BaO:
MgO + CaO + SrO + BaO is related to the improvement of meltability of glass. If the total amount is less than 10% by weight, desired meltability cannot be obtained. On the other hand, when it exceeds 19% by weight, devitrification tends to occur. Therefore, the range of 10 to 19% by weight, and further 12 to 19% by weight is preferably used.
[0026]
TiO 2 :
TiO 2 is not an essential component but is effective in improving chemical durability. If it exceeds 3% by weight, the glass is colored, which is not preferable. Therefore, a range of 0 to 3% by weight, and further 0 to 1% by weight is preferably used.
[0027]
ZnO:
ZnO is not an essential component but is effective for improving the meltability. However, if it exceeds 2% by weight, the volatilization is large and the life of the glass melting furnace is shortened. Accordingly, a range of 0 to 2% by weight, and further 0 to 1% by weight is preferably used.
[0028]
SO 3 + Sb 2 O 3 :
SO 3 + Sb 2 O 3 is not an essential component but is used as a fining agent. The amount used is preferably 1% by weight or less.
[0029]
In the present invention, oxides such as V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Ru, and Ce are added as coloring components in order to adjust the transmittance of glass and increase the display contrast of PDP. You may do it.
[0030]
In order to match the expansion coefficient of a sealing frit or the like used when manufacturing a PDP, the average expansion coefficient of 50 to 350 ° C. needs to be 75 to 95 × 10 −7 / ° C. Furthermore, the range of 80-90 * 10 < -7 > / (degreeC) is preferable. Further, in order to keep the heat shrinkage in the heat treatment during the manufacturing process of the PDP below an allowable range, the transition point is required to be 650 ° C. or higher, and preferably 660 ° C. or higher.
[0031]
Next, the present invention will be described with reference to examples and comparative examples.
The glass raw material was prepared so that the glass component of the example had the target composition shown in Table 1. At this time, bow glass was used as a fining agent. The prepared batch was put into a crucible, melted at 1600 ° C. for 4 hours, then poured out and cooled. The melting temperature (viscosity of 10 2 poise), working temperature (viscosity of 10 4 poise), devitrification temperature, expansion coefficient, and transition point of the glass sample thus obtained were measured.
[0032]
Melting temperature and working temperature were measured as follows. A glass was put into a 70 cc platinum crucible and melted at 1600 ° C. to obtain a measurement sample. Set this sample in a sample pull-down high-temperature viscosity measuring device, hang a platinum ball in the molten glass of the sample, measure the viscosity resistance applied to the platinum ball when pulling down the sample with the container as a load, and measure the viscosity at each temperature. Asked. The relationship between temperature and viscosity was measured in the temperature range of 900 to 1600 ° C.
[0033]
The devitrification temperature was measured as follows. The glass particles are crushed and 25 g of glass particles passing through a 2830 μm sieve and remaining on a 1000 μm sieve are measured, and the glass particles are spread on a platinum boat having a width of 12 mm, a length of 200 mm, and a depth of 9 mm. And hold for 2 hours in a furnace set at a temperature so as to have an appropriate temperature gradient. After allowing the platinum boat taken out of the furnace to cool naturally, the glass on the platinum boat was observed using a 50 × telescope, and the devitrification temperature was set to the maximum temperature at which devitrification occurred.
[0034]
The expansion coefficient was measured as follows. A cylindrical rod having a diameter of 5 mm and a height of 15 mm was produced, the relationship between temperature and glass elongation was measured from 25 ° C. to the yield point of the glass, and the expansion coefficient between 50 ° C. and 350 ° C. was measured.
[0035]
The transition point was measured as follows. A tangent line was drawn before and after the first bending point of the expansion curve at the time of expansion coefficient measurement, and the temperature corresponding to the intersection of the two tangent lines was taken as the transition point.
[0036]
The measurement results of each characteristic are shown in Table 1. As can be seen from Table 1, the glass compositions of Examples 1 to 6 all have a melting temperature of less than 1600 ° C., and the relationship between the working temperature (Tw) and the devitrification temperature (Tl) is Tw− Tl ≧ 15 ° C. Moreover, the transition point of glass was 660 degreeC or more, and the average expansion coefficient of 50-350 degreeC was 80-90 * 10 < -7 > / degreeC. That is, these glass compositions have a good matching with the expansion coefficient of the sealing frit used at the time of manufacturing the PDP, and have been found to be suitable as a glass substrate for a display device such as a PDP.
[0037]
In addition, the symbol of Table 1 and Table 2 is as follows.
N.W.F (network former) = SiO 2 + Al 2 O 3 + ZrO 2
R 2 O = Li 2 O + Na 2 O + K 2 O
R′O = MgO + CaO + SrO + BaO
[0038]
[Table 1]
[Table 2]
Comparative Examples Glass compositions of Comparative Examples 1 to 4 shown in Table 2 were prepared in the same manner as in the Examples, and the melting temperature, working temperature, devitrification temperature, transition point, and thermal expansion of the obtained glass samples. The rate was measured. Each characteristic was measured by the same method as the Example. The glasses of Comparative Example 1 and Comparative Example 2 have compositions disclosed in JP-A-9-255355 and JP-A-9-255356, respectively, and the devitrification temperature is as high as 200 ° C. or more with respect to the working temperature. It was found that the glass is easily devitrified and is difficult to melt and mold by the float process. Moreover, it was found that the specific gravity exceeds 3.0, which is not preferable as a glass for PDP that requires a reduction in weight.
[0041]
On the other hand, the glasses of Comparative Example 3 and Comparative Example 4 have compositions disclosed in JP-A-9-301732 and JP-A-9-301733, respectively, and have low devitrification temperature and low specific gravity with respect to the working temperature. Since the melting temperature is close to 1700 ° C. and the working temperature is 1200 ° C. or higher, melting is difficult in the melting furnace of the float method.
[0042]
【The invention's effect】
Since the glass composition of the present invention has a high transition point, when it is used as a glass substrate for PDP, the amount of heat shrinkage of the glass caused by the heat treatment received in the PDP manufacturing process can be suppressed to be small. For this reason, the thermal stability of the dimension of glass required for manufacture of a large sized or high definition PDP is securable. In addition, since the glass substrate made of the glass composition of the present invention has a value of expansion coefficient within a predetermined range, it has good thermal matching with a member such as a glass frit already used in the manufacture of PDP, and is airtight and reliable. A compatible PDP can be manufactured.
[0043]
Furthermore, since the melting temperature, devitrification temperature, and working temperature are selected within the predetermined range, the glass composition of the present invention can be melted without causing melting defects such as devitrification by the float process. Can be formed into a shape.
Claims (5)
ＳｉＯ2：５０〜５４．９
Ａｌ2Ｏ3：１０．５〜１８
ＺｒＯ2：１〜６
Ｂ2Ｏ3：０〜３
Ｌｉ2Ｏ：０〜１
Ｎａ2Ｏ：０〜１０
Ｋ2Ｏ：０〜１５
ＭｇＯ：０〜８
ＣａＯ：４〜８
ＳｒＯ：０〜４
ＢａＯ：３〜１２
ＴｉＯ2：０〜３
ＺｎＯ：０〜２
ＳＯ3＋Ｓｂ2Ｏ3：０〜１
ＳｉＯ2＋Ａｌ2Ｏ3＋ＺｒＯ2：７０．１以上
Ｌｉ2Ｏ＋ＮａaＯ＋Ｋ2Ｏ：６〜１９
ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯ：１０〜１９
かつ、５０〜３５０℃の平均膨張率が７５〜９５×１０-7／℃、転移点が６５０℃以上である耐熱性ガラス組成物。The following composition expressed in weight%,
SiO 2: 50~54.9
Al 2 O 3 : 10.5-18
ZrO 2 : 1 to 6
B 2 O 3 : 0 to 3
Li 2 O: 0 to 1
Na 2 O: 0 to 10
K 2 O: 0~15
MgO: 0-8
CaO: 4-8
SrO: 0-4
BaO: 3-12
TiO 2 : 0 to 3
ZnO: 0 to 2
SO 3 + Sb 2 O 3 : 0 to 1
SiO 2 + Al 2 O 3 + ZrO 2 : 70.1 or more Li 2 O + Na a O + K 2 O: 6 to 19
MgO + CaO + SrO + BaO: 10-19
And the heat resistant glass composition whose average expansion coefficient of 50-350 degreeC is 75-95 * 10 < -7 > / degreeC, and a transition point is 650 degreeC or more.
ＳｉＯ2：５２．５〜５４．５
Ａｌ2Ｏ3：１１．０〜１５
ＺｒＯ2：２．５〜５．５
Ｂ2Ｏ3：０〜２
Ｌｉ2Ｏ：０〜０．５
Ｎａ2Ｏ：４〜７
Ｋ2Ｏ：４〜１０
ＭｇＯ：０〜６
ＣａＯ：４〜７
ＳｒＯ：０〜４
ＢａＯ：４〜９
ＴｉＯ2：０〜１
ＺｎＯ：０〜１
ＳＯ3＋Ｓｂ2Ｏ3：０〜１
ＳｉＯ2＋Ａｌ2Ｏ3＋ＺｒＯ2：７０．５以上
Ｌｉ2Ｏ＋Ｎａ2Ｏ＋Ｋ2Ｏ：９〜１５
ＭｇＯ＋ＣａＯ＋ＳｒＯ＋ＢａＯ：１２〜１９
かつ、５０〜３５０℃の平均膨張率が８０〜９０×１０-7／℃、転移点が６６０℃以上であることを特徴とする請求項１または２に記載の耐熱性ガラス組成物。The following composition expressed in weight%,
SiO 2: 52.5~54.5
Al 2 O 3 : 11.0-15
ZrO 2 : 2.5 to 5.5
B 2 O 3 : 0 to 2
Li 2 O: 0 to 0.5
Na 2 O: 4~7
K 2 O: 4 to 10
MgO: 0-6
CaO: 4-7
SrO: 0-4
BaO: 4-9
TiO 2 : 0 to 1
ZnO: 0 to 1
SO 3 + Sb 2 O 3 : 0 to 1
SiO 2 + Al 2 O 3 + ZrO 2 : 70.5 or more Li 2 O + Na 2 O + K 2 O: 9 to 15
MgO + CaO + SrO + BaO: 12-19
And the average expansion coefficient of 50-350 degreeC is 80-90 * 10 < -7 > / degreeC, and a transition point is 660 degreeC or more, The heat resistant glass composition of Claim 1 or 2 characterized by the above-mentioned.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23697198A JP4045662B2 (en) | 1998-08-24 | 1998-08-24 | Heat resistant glass composition and plasma display panel using the same |
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| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP23697198A JP4045662B2 (en) | 1998-08-24 | 1998-08-24 | Heat resistant glass composition and plasma display panel using the same |
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| JP4045662B2 true JP4045662B2 (en) | 2008-02-13 |
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| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2003112942A (en) * | 2001-10-03 | 2003-04-18 | Nippon Electric Glass Co Ltd | Glass substrate for field emission type display |
| AU2003281111A1 (en) * | 2002-07-16 | 2004-02-02 | Tdk Corporation | Flat panel display substrate and thin film el element |
| JP2006030486A (en) * | 2004-07-14 | 2006-02-02 | Osaka Tokushu Glass Kk | Reflecting mirror |
| KR100750990B1 (en) | 2005-06-22 | 2007-08-22 | 주식회사 케이씨씨 | High Strain-point Glass composition for substrate |
| KR100794200B1 (en) * | 2005-12-16 | 2008-01-11 | 한상교 | A manufacturing method of unrefined rice wine |
| JP4946310B2 (en) * | 2006-09-25 | 2012-06-06 | セントラル硝子株式会社 | Substrate glass for display devices |
| KR100846283B1 (en) | 2007-03-07 | 2008-07-16 | 샌트랄 글래스 컴퍼니 리미티드 | A substrate glass for a flat panel display device |
| DE202009018699U1 (en) | 2008-02-26 | 2012-11-20 | Corning Incorporated | Refining agent for silicate glasses |
| JP5915891B2 (en) * | 2011-05-10 | 2016-05-11 | 日本電気硝子株式会社 | Glass |
| JPWO2015076208A1 (en) * | 2013-11-19 | 2017-03-16 | 旭硝子株式会社 | Glass plate |
| CN105923995A (en) * | 2016-04-26 | 2016-09-07 | 东莞市银通玻璃有限公司 | Ultrathin toughened glass and preparation method thereof |
| CN115745398A (en) * | 2022-11-30 | 2023-03-07 | 成都光明光电股份有限公司 | Glass composition |
-
1998
- 1998-08-24 JP JP23697198A patent/JP4045662B2/en not_active Expired - Lifetime
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|---|---|
| JP2000072472A (en) | 2000-03-07 |
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