1351710 九、發明說明： 【發明所屬之技術領域】 電 螢 省 體 端 放 部 接 於 左 電 薄 質 金 極 本發明係關k例如作為液晶的背光使用之螢光放 管、其電極及電極用合金。 【先前技術】 於液晶裝置中係使用小型的螢光放電管作為背光。此 光放電管係如圖 3所示，於内壁面形成有螢光膜（圊示 略），具備有：在内部封入放電用氣體（氬氣等之稀有氣 及汞蒸氣）之玻璃管11、與構成設置於該玻璃管11的兩 部之一對冷陰極之電極1 2。前述電極1 2係由一端為開 之筒狀的管部 13與將此管部 13 的另一端封閉的端板 14，一體形成為有底筒狀（杯狀）。於前述端板部14，炫 著貫穿前述玻璃管11的端部並密封的棒狀導電體15之 端，此導電體1 5之另一端則連接著導線1 7。 前述電極12，向來係由純鎳（Ni)形成，關於其尺寸， 背光等之小型的螢光放電管用者，例如為内徑 1.5mm 右、全長5mm左右、管部13的厚度0.1mm左右。此筒狀 極通常係由具有與前述管部的壁厚相同之厚度的純 Ni 板藉由深拉引成形而一體成形。 如上述般，螢光放電管電極向來係以成形性良好且材 安定的純N i形成，惟，燈管壽命較短，是問題所在。亦即 螢光放電管於點燈時，會發生離子等衝擊電極而自電極 屬放出原子的現象（即，濺射）。藉由此濺射所放出的電 金屬之原子會與封入於玻璃管内的汞鍵結，而消耗玻璃管 6 1351710 内之汞蒸氣。向來，形成電極金屬的Ni，於濺射時之原子 放出量多，亦即藏射率高，汞之消耗量大，致放電管的壽 命容易降低，是問題所在。 因此，近年來，如日本專利特開2002-110085號公報（專 利文獻1)中所記載般，嘗試將電極以濺射率低之鈮（Nb)、 鈦（Ti)、钽（Ta)或此等之合金來形成。 專利文獻1 :日本專利特開2 0 0 2 - 1 1 0 0 8 5號公報（申請專利 範圍） 【發明内容】 (發明所欲解決之問題） 然而，此等金屬元素與 N i相比較為昂貴，且為高熔點 之容易氧化的材料，故於製造時，必須藉由電漿電弧熔解 法或粉末冶金法等之與通常的熔解-鑄造法不同之特殊方 法來製造粗塊（bulk)材。又，於Nb方面，雖可對其薄板施 行深拉引加工，惟，必須於粗塊材之軋製時反覆進行真空 退火等之無氧化環境下之退火與軋製，以作成薄板。如此， 關於Nb、Ta等，整體而言，於製造小型筒狀電極方面，成 形加工性差，製造成本非常高，是問題所在。 本發明係有鑑於上述問題而提出者，目的在於提供：與 Ni電極相比，燈管壽命較長、且成形加工性優異之螢光放 電管電極用合金，由該合金所形成的螢光放電管電極，以 及具有該電極之螢光放電管。 (解決問題之手段） 本發明之發明者，針對相應於鎳-鈮（Ni-Nb)合金之 Nb 7 1351710 添加量之濺射率的變化詳細地觀察，發現：少量的Nb之添 加會使藏射率減少’另一方面’若添加過多 Nb，則於Ni_Nb 合金中會生成金屬間化合物，濺射率上升，同時 其加工性會變差，本發明於焉得以完成。 亦即，本發明之螢光放電管電極用合金，係由含有以質 量％(以下僅以「％」表示）計為Nb2.0%以上、未滿6.0%，殘 餘部分為Ni及不可避免之雜質所構成之Ni-Nb合金形成。 由於此電極用合金係為含有 Nb2.0%以上、未滿 6.0%， 殘餘部分為Ni及不可避免之雜質所構成之Ni-Nb合金，雖 與只由濺射率低的 Nb來形成電極的情況相比，濺射率稍 高，但Nb添加量為2.0%以上、未滿6.0%之少量，故於Ni-Nb 合金中不會生成Ni與Nb之金屬間化合物，Ni與Nb成為 固溶狀態。因此，與以往之以純N i形成電極的情況相比， 可降低濺射率，並可提高燈管之壽命。另一方面，若為6.0% 以上，Ni-Nb合金中會生成 NbNi8之金屬間化合物，濺射 率會上昇，且成形性會變差。而且，於Nb量為2.0%以上、 未滿6.0 %的程度，於實用上，與純Ni的情況可同樣地熔 解與鑄造，不須使用電漿電弧熔解或真空退火即可製造。 而且，由於有良好的成形加工性，可容易地進行深拉引成 形或冷閉塞鍛造（衝壓成形）為小型的筒狀電極，生產性優。 又，本發明之螢光放電管用電極具備：一端為開放之管 部、與將該管部之另一端封閉之端板部，該管部與端板部 係用前述Ni-Nb合金一體成形。使用此電極，可具有以前 述Ni-Nb合金形成所帶來之優點 8 1351710 於前述電極中，該端板部以形成為較管部之管壁厚更厚 為佳。藉由如此形成，即使於管部的管壁厚度較薄的情況， 由於給電用導電體所熔接之端板部的厚度係形成為較管部 之管壁厚度更厚，故於將前述導電體的端部抵住端板部而 熔接時，可不須精確地控制熔接輸出等之熔接輸出，即可 容易地將導電體的端部熔接至端板部，可防止兩者之熔接 不良。因此，導電體與電極可確實地電性接合、熱接合， 放電狀態、放熱狀態安定，可防止螢光放電管的燈管壽命 降低，且可提高螢光放電管之製造良率。 於前述電極中，以於該端板部之外側設置配置成與該管 部為同心狀之導電體定位用凹部為佳。藉由設置此導電體 定位用凹部，只須將導電體的端部插入前述凹部並熔接， 即可將導電體確實地熔接於電極的端板部並成同心狀。因 此，藉由使導電體密封於玻璃管端部成同心狀，使電極與 玻璃管配置成同心狀，可提高玻璃管内放電狀態之均一 性、安定性，而可更加提高燈管壽命。 又，本發明之螢光放電管具備：内壁面形成有螢光膜， 且於其内部封入放電用氣體之玻璃管；於該玻璃管之兩端 部密封成與玻璃管為同心狀且貫穿著玻璃管的内外之給電 用導電體；與配置於該玻璃管内部，並連接至該給電用導 電體之端部的一對電極；該電極係用上述本發明之螢光放 電管用電極，於該電極的端板部之外側熔接著該給電用導 電體並成同心狀。使用此螢光放電管，可具備得自上述本 發明之電極之各種效果 9 1351710 如上述說明般，本發明之螢光放電管電極用合金 Ni中少量含有 Nb2.0%以上、未滿6.0%，故於Ni-中不易生成NiNb金屬間化合物，Ni與Nb為固溶壯 在無損於深拉引成形或衝壓成形等成形加工之下， 降低與純N i相比之濺射率，致使燈管壽命得以改4 本發明之電極，為以前述電極用合金形成者。於前 中，藉由使端板部的厚度形成為較管部的管壁厚更 給電用導電體容易熔接，與電極可確實地電性接合 合，放電狀態、放熱狀態安定，可防止螢光放電管 壽命的降低，且可提高螢光放電管之製造良率。 【實施方式】 本發明之螢光放電管電極用合金為含有作為合 之Nb2.0%以上、未滿6.0%，殘餘部分為Ni及不可 雜質所構成之 Ni-Nb合金。由於 2.0%以上、未滿 Mb添加量，不易生成NiNb金屬間化合物，Ni與Nb 狀態，故成形性、加工性不會變差，濺射率隨著添 比例而有效地降低》亦即，若未滿 2. 0 %，則 N b量 另一方面，若為 6.0%以上，會於Ni-Nb合金中生4 金屬間化合物，致滅射率反而上昇，且成形性、加 差。因此，Nb量的下限定為 2.0%，以超過3.0%為 上限定為未滿6.0%，以5. 5%為佳。 前述電極用合金雖含有高熔點之難加工性元素， Ni同樣地成形性、加工性優異，故於大氣下鑄造之 其鑄造片於大氣下進行熱軋製，於需要時在鈍氣環 -，由於 Nb合金 .態，可 有效地 f。又， 述電極 厚，使 、熱接 的燈管 金元素 避免之 6. 0% 之 為固溶 加量的 過少， (,NbN i 8 工性變 佳，其 但與純 後，將 境下退 10 1351710 火後，再進行冷軋製，藉此，可加工成0.1mm左右之每 而且，視需要，於加工退火（軟化退火）後，藉由對前 材進行深拉引成形，可製造筒狀電極"深拉引成形與 衝壓成形相比，量產性優異是其優點。 又，藉由對鑄造片進行熱軋製或熱鍛造加工成棒材 其進行拉線加工，將得到的線材切斷成適當的長度而 短軸狀材料（稱為碎料（slug))，視需要，於加工退火 藉由對其進行衝壓成形（冷閉塞鍛造）可得到筒狀電極 衝壓成形的情況，可較容易使筒狀電極的端板部之板 成為較筒狀部厚，而且，可容易在端板部一體成形成 體定位用凹部，生產性優異。 又，加工退火可於800〜950 °C左右保持3分鐘至3 /J 由於Nb易氧化及氮化，故退火環境以在真空環境或氬 等惰性氣體環境_進行為佳。前述「8 0 0〜9 5 0 °C」，係指 。(：以上、950 °C以下。以下，「N1(數字）~N2(數字）」， N 1以上、N 2以下。 其次，就本發明之實施形態之螢光放電管及其電極 說明。圖1為實施形態的螢光放電管之重要部分截面 此螢光放電管具備：於内壁面形成有螢光膜 8，並封 電用氣體（氬氣等之稀有氣體及汞蒸氣）之玻璃管 1; 置於該玻璃管1的兩端部之一對構成冷陰極的電極2 前述電極2係由一端為開放之管部3、與將此管部 一端封閉之端板部 4所一體形成。於前述端板部 4， 給電用之棒狀導電體 5與前述管部 3排列成同心狀 片° 述片 上述 ，對 得到 後， 。於 厚作 導電 、時。 (Ar) 800 係指 加以 圖， 入放 與設 〇 3之 以使 之方 π 1351710 式，形成有前述導電體5的一端可嵌合之導電體定位 部6。前述導電體5，係以將玻璃管1的端部内外貫穿 式而密封，於玻璃管1之内側端部係嵌合於前述凹部 於與端板部4的境界外周部，藉由雷射熔接、電阻熔 焊等而熔接。於位於前述玻璃管1的外側之前述導電 的另一端連接有給電用導線7。 前述端板部4的厚度（導電體5熔接的部位之厚度 須形成為較前述管部3的管壁厚度更厚，俾便形成前 部6，並使導電體5可充分地熔接於端板部4。於小型 光放電管，電極2的長度為4〜10mm左右、管部3的壁 形成為0.08~0. 2mm左右，前述端板部4的厚度係形成 述管部3的壁厚之3〜10倍左右。又，於端板部4之凹 的深度宜為管部3的管壁厚以上，以管壁厚的2倍以 佳，又，凹部6之底面與管部側内面之壁厚須為管壁 厚程度以上。 前述電極2係以前述Ni-Nb電極用合金形成。藉由 前述Ni-Nb合金，具有良好的冷成形性，同時其濺射 可較純Ni降低，可提高燈管壽命。此筒狀電極可藉由 成形而一體成形。 於上述實施形態中，係以導電體定位用凹部6 —體 於端板部4的例子來表示，惟，前述凹部6並非一定必 其本意在於，藉由形成前述凹部6，可使導電體5與電 的管部3配置成同心狀，故藉由使前述導電體5密封 璃管1成同心狀，可使電極2與玻璃管1容易地配置 用凹 之方 6， 接銅 體5 t)， 述凹 的螢 厚係 為前 部6 上為 的壁 使用 率亦 衝壓 成形 要。 極2 於玻 成同 12 1351710 心狀，可防止放電狀態的不均一化，而可期放電 並提高燈管壽命。當然，螢光放電管電極並不限 形，亦可為圖3所示般之藉由深拉引成形而成形 狀者。 以下，舉出實施例就本發明更具體地加以說明 發明並非限定於此等實施例者。 (實施例） 將表1所示之各種Nb量的Ni-Nb合金（4kg)以 爐於1500 °C熔解，將用各熔液所鑄造之鑄造片於 1 1 0 0 °C下進行熱鍛造後，以1 1 0 0 °C之軋製開始溫 軋製，得到各Ni-Nb合金之熱軋製板及熱軋線材 熱軋材於氮及氫之混合氣體（大氣）中進行退火（ 保持2小時）。然後，對前述熱軋製板進行冷軋製 板厚為0.15mm的薄板。並對前述熱軋線材進行冷 工成外徑1.7ιηιηφ的線材。用如此製作之試料進行 評估，並測定濺射率。加工性係藉由衝壓成形試 引成形試驗（艾里克森試驗）進行評估。 衝壓成形試驗係將前述線材切斷成1.8mm之碎 加工退火（真空環境下，於9 0 0 °C保持2小時）後 實際進行成形為圖 2所示之内徑 外徑 全長 5.4mm、導電體定位用凹部深度0.2mm的筒 進行。使用之成形模具之衝頭（punch)為外徑 1. 端部之張開角度為150°，材質為模具鋼（JIS規格 另一方面，模頭為内徑材質為超硬合金 安定化、 於衝壓成 為有底筒 ，惟，本 真空感應 大氣中在 度進行熱 。將此等 於 9 0 0 °C ，加工成 拉線，加 加工性之 驗、深拉 料，進行 ，使用其 1 . 7 m m φ ' 狀電極而 5 m m φ ' 前 SKD 1 1 ) ° (D種第6 13 1351710 號）。 衝壓成形性評估係依據下述基準：於成形次數達到1000 次時，模頭未破損，衝頭未變形，可繼續進行成形者，評 定為 A A ;可成形5 0 0次以上，惟，於達到1 0 0 0次之前， 模頭已破損或衝頭已變形，致無法進行成形者，評定為A; 於達到500次之前，模頭已破損或衝頭已變形，致無法進 行成形者，評定為B。較佳者為實用上可成形500次以上， 亦即前述AA或A。 深拉引成形試驗係將前述薄板切斷成100mm見方，進行 加工退火（於真空環境下，於9 0 0 °C保持2小時）後，使用 其依循JISB7729、7777進行艾里克森試驗。艾里克森試 驗係對退火試料板以直徑2 0 m m的球狀衝頭，以5〜2 0 m m / m i η 的擠壓速度對試料表面進行擠壓直到產生裂痕為止，測出 於試料表面產生裂痕時為止之衝頭前端的移動距離（稱為 艾里克森值。單位mm)，艾里克森值若為10以上，則’拉 引性良好，為實用上無問題之水準。 又，濺射率係藉由下述要領測定。自前述N i - N b合金薄 板採取試驗片（lOmmxlOmm)，對試驗面進行鏡面研磨。用離 子束裝置（Veeco公司製，型式：VE-747)，以前述試驗片 為靶，於靶與基板間施加電壓（500V)，以氬離子（1·3χ 10_6Torr)對試驗面進行一定時間（120min)之加速衝壓，進 行濺射。於試驗面將鏡面的一部分遮蓋形成非濺射部，於 濺射後，藉由濺射而將試驗片的鏡面部削除形成之濺射部 與遮蓋住之非濺射部之間形成高度差。對此高度差用接觸 14 1351710 式粗度計（Sloan 公司製，型式：DEKTAK2A)測定，由下式 求出濺射率（A/min)。又，將各試料的濺射率除以純Ni(試 料No. 1)，求出相對藏射率。此等測定值一併示於表1。又， 將Mb量與相對濺射率的關係整理成的曲線圖示如圖4。 濺射率=高度差（A) /濺射時間（120min) [表1] 試料N 〇. Nb量 % 南度差 A 濺射率 A/m i η 相對濺射率 % 衝壓 成形性 艾里克森值 mm 備註 1 0.0 29443 245. 4 100 ΑΑ 11.3 習知例 2 2. 0 28267 235.6 96. 0 ΑΑ 10.3 發明例 3 3. 1 27928 232. 7 94. 9 A 10.4 發明例 4 5. 0 2781 6 231.8 94. 5 A 10.6 發明例 5 7. 0 28822 240. 2 97. 9 B 6.8 比較例 6 9. 0 28928 241. 1 98. 3 B 6. 7 比較例 7 11.0 28951 241.3 98. 3 B 6. 6 比較例 由表1、圖4可知，發明例之試料N 〇. 2至N 〇. 4，相對激 射率為9 6 %以下，N b造成之良好的降低濺射之效果得以確 認，衝壓成形性、深拉引成形性皆達實用之水準亦得以確 認。另一方面，由圖4可知，Nb量超過6%之試料No. 5至 N 〇. 9 *因Nb之添加，原經抑制之減射率再度轉而上昇，反 而使濺射率變差，且成形性亦變差。 15 1351710 【圖式簡單說明】 圖1為具備本發明之實施形態之螢光放電管電極的螢光 放電管之重要部分截面圖。 圖2為本發明之實施例中衝壓成形之螢光放電管電極之 截面圖。 圖3為具備習知的螢光放電管電極之螢光放電管之重要 部分截面圖。 圖 4為表示實施例中Nb添加量與相對濺射率的關係之 曲線圖。 【主要元件符號說明】 1 玻璃管 2 電極 3 管部 4 端板部 5 導電體 6 導電體定位用凹部 7 給電用導線 8 螢光膜 11 玻璃管 12 電極 13 管部 14 端板部 15 導電體 17 導線 161351710 IX. Description of the invention: [Technical field of the invention] The electroluminescence body end portion is connected to the left electric thin gold electrode. The invention is used for the fluorescent tube, which is used as a liquid crystal backlight, and the electrode and the electrode thereof. alloy. [Prior Art] A small fluorescent discharge tube is used as a backlight in a liquid crystal device. As shown in FIG. 3, the photo-discharge tube is formed with a fluorescent film (not shown) on the inner wall surface, and a glass tube 11 in which a discharge gas (rare gas such as argon gas or mercury vapor) is sealed inside, And an electrode 12 which is formed on one of the two portions of the glass tube 11 and which is a pair of cold cathodes. The electrode 12 is integrally formed into a bottomed cylindrical shape (cup shape) by a tubular portion 13 having an open cylindrical shape and an end plate 14 closed to the other end of the tubular portion 13. In the end plate portion 14, the end of the rod-shaped electric conductor 15 which penetrates the end portion of the glass tube 11 and is sealed is slid, and the other end of the electric conductor 15 is connected to the lead wire 17. The electrode 12 is formed of pure nickel (Ni), and the small-sized fluorescent discharge tube of the size or the like is, for example, an inner diameter of 1.5 mm, a right length of about 5 mm, and a tube portion 13 having a thickness of about 0.1 mm. The cylindrical pole is usually integrally formed by deep drawing by a pure Ni plate having the same thickness as the wall thickness of the tube portion. As described above, the fluorescent discharge tube electrode has been conventionally formed of pure Ni which is excellent in formability and stable in material, but the life of the tube is short, which is a problem. That is, when the fluorescent discharge tube is lit, a phenomenon in which an electrode such as an ion strikes an atom and emits atoms from the electrode (i.e., sputtering) occurs. The atoms of the electric metal released by the sputtering are bonded to the mercury enclosed in the glass tube, and the mercury vapor in the glass tube 6 1351710 is consumed. In the past, Ni which forms the electrode metal has a large amount of atomic emission during sputtering, that is, a high storage rate, a large consumption of mercury, and a low life of the discharge tube, which is a problem. Therefore, in recent years, as described in Japanese Laid-Open Patent Publication No. 2002-110085 (Patent Document 1), attempts have been made to reduce the electrode (Nb), titanium (Ti), tantalum (Ta) or the like with a low sputtering rate. The alloy is formed. Patent Document 1: Japanese Patent Laid-Open Publication No. Hei 2 0 0 2 - 1 0 0 8 5 (Application Patent Field) [Disclosure] (The problem to be solved by the invention) However, these metal elements are more compared with N i It is expensive and is a material that is easily oxidized at a high melting point. Therefore, it is necessary to manufacture a bulk material by a special method different from the usual melting-casting method, such as plasma arc melting or powder metallurgy. . Further, in the case of Nb, deep drawing may be performed on the thin plate, but it is necessary to perform annealing and rolling in an oxidizing-free environment such as vacuum annealing in the rolling of the coarse block to form a thin plate. As described above, Nb, Ta, and the like are generally poor in the formability of the small cylindrical electrode, and the manufacturing cost is extremely high, which is a problem. The present invention has been made in view of the above-mentioned problems, and an object of the invention is to provide an alloy for a fluorescent discharge tube electrode having a longer lamp life and excellent moldability than a Ni electrode, and a fluorescent discharge formed by the alloy. a tube electrode, and a fluorescent discharge tube having the electrode. (Means for Solving the Problem) The inventors of the present invention observed in detail the change in the sputtering rate of the amount of addition of Nb 7 1351710 corresponding to the nickel-niobium (Ni-Nb) alloy, and found that the addition of a small amount of Nb would cause hiding. When the amount of radiation is reduced, on the other hand, if too much Nb is added, an intermetallic compound is formed in the Ni_Nb alloy, the sputtering rate is increased, and the workability is deteriorated, and the present invention is completed. In other words, the alloy for a fluorescent discharge tube electrode of the present invention contains Nb of 2.0% or more and less than 6.0% by mass% (hereinafter referred to as "%"), and the residual portion is Ni and inevitable. A Ni-Nb alloy composed of impurities is formed. The alloy for the electrode is a Ni-Nb alloy containing Nb of 2.0% or more and less than 6.0%, and the remaining part is Ni and unavoidable impurities, and the electrode is formed only by Nb having a low sputtering rate. In contrast, the sputtering rate is slightly higher, but the amount of Nb added is 2.0% or more and less than 6.0%. Therefore, an intermetallic compound of Ni and Nb is not formed in the Ni-Nb alloy, and Ni and Nb become solid solution. status. Therefore, the sputtering rate can be lowered and the life of the lamp can be improved as compared with the case where the electrode is conventionally formed of pure Ni. On the other hand, when it is 6.0% or more, an intermetallic compound of NbNi8 is formed in the Ni-Nb alloy, and the sputtering rate is increased, and the formability is deteriorated. Further, in the case where the amount of Nb is 2.0% or more and less than 6.0%, it can be practically melted and cast in the same manner as in the case of pure Ni, and it can be produced without using plasma arc melting or vacuum annealing. Further, since it has good moldability, it can be easily subjected to deep drawing forming or cold blocking forging (press forming) into a small cylindrical electrode, and is excellent in productivity. Further, the electrode for a fluorescent discharge tube according to the present invention comprises an end plate portion having an open end and a closed end portion of the tube portion, and the tube portion and the end plate portion are integrally molded by the Ni-Nb alloy. The use of this electrode can have the advantages of the formation of the Ni-Nb alloy described above. 8 1351710 In the above electrode, the end plate portion is preferably formed thicker than the tube wall of the tube portion. By forming in this manner, even when the thickness of the tube wall of the tube portion is thin, the thickness of the end plate portion to which the electric conductor for electric conduction is welded is formed to be thicker than the thickness of the tube wall of the tube portion, so that the electric conductor is formed When the end portion is welded against the end plate portion, the end portion of the conductor can be easily welded to the end plate portion without precisely controlling the welding output such as the welding output, and the welding failure between the two can be prevented. Therefore, the conductor and the electrode can be reliably electrically and thermally bonded, and the discharge state and the heat release state are stabilized, whereby the life of the lamp of the fluorescent discharge tube can be prevented from being lowered, and the manufacturing yield of the fluorescent discharge tube can be improved. In the above electrode, it is preferable to provide a recess for positioning a conductor which is disposed concentrically with the tube portion on the outer side of the end plate portion. By providing the recess for positioning the conductor, the conductor can be surely welded to the end plate portion of the electrode and concentrically formed by inserting the end portion of the conductor into the recess and welding it. Therefore, by sealing the conductor to the end portion of the glass tube so as to be concentric with the glass tube, the uniformity and stability of the discharge state in the glass tube can be improved, and the life of the tube can be further improved. Further, the fluorescent discharge tube of the present invention includes a glass tube in which a fluorescent film is formed on the inner wall surface and a discharge gas is sealed in the inside, and the both ends of the glass tube are sealed so as to be concentric with the glass tube and penetrate therethrough. a conductor for supplying electricity inside and outside the glass tube; and a pair of electrodes disposed inside the glass tube and connected to an end portion of the power supply conductor; wherein the electrode is the electrode for a fluorescent discharge tube of the present invention The outer side of the end plate portion of the electrode is welded to the electric conductor for electric conduction and is concentric. The fluorescent discharge tube can be provided with various effects of the electrode of the present invention. 9 1351710 As described above, the alloy Ni for a fluorescent discharge tube electrode of the present invention contains a small amount of Nb of 2.0% or more and less than 6.0%. Therefore, it is difficult to form NiNb intermetallic compound in Ni-, and Ni and Nb are solid solution and strong under the forming process such as deep drawing or stamping, which reduces the sputtering rate compared with pure N i, resulting in lamp The tube life is changed. The electrode of the present invention is formed of the alloy for the electrode. In the prior art, the thickness of the end plate portion is formed to be more easily welded to the electrical conductor than the tube wall thickness of the tube portion, and the electrode can be reliably electrically joined to each other, and the discharge state and the heat release state are stabilized, thereby preventing fluorescence. The life of the discharge tube is reduced, and the manufacturing yield of the fluorescent discharge tube can be improved. [Embodiment] The alloy for a fluorescent discharge tube electrode of the present invention contains a Ni-Nb alloy containing 2.0% or more of Nb, less than 6.0%, and a residual portion of Ni and no impurities. When the amount of addition of Mb is less than 2.0%, the NiNb intermetallic compound is not easily formed, and the Ni and Nb states are not deteriorated, and the moldability and workability are not deteriorated, and the sputtering rate is effectively lowered as the ratio is increased. When the amount is less than 2.0%, the amount of Nb is on the other hand, and if it is 6.0% or more, the intermetallic compound is formed in the Ni-Nb alloy, and the rate of incineration is increased, and the formability and the difference are increased. 5%。 Preferably, the amount of Nb is limited to 2.0%, more than 3.0% is limited to less than 6.0%, preferably 5.5%. The alloy for an electrode contains a difficult-to-process element having a high melting point, and Ni is excellent in formability and workability in the same manner. Therefore, the cast piece cast in the atmosphere is hot-rolled in the air, and if necessary, in an obligate gas ring - Due to the Nb alloy state, it can be effectively f. In addition, the thickness of the electrode is such that the gold element of the heat-exchanged lamp tube is avoided. 6. 0% is too small for the solid solution addition amount. (NbN i 8 workability is good, but after pure, it will fall back 10 1351710 After the fire, cold rolling is carried out, whereby it can be processed into about 0.1 mm and, if necessary, after processing annealing (softening annealing), by deep drawing the front material, the cylinder can be manufactured. "Electrode" "Deep pull forming is superior to press forming in terms of mass productivity. Further, the cast wire is subjected to hot rolling or hot forging to form a bar and subjected to wire drawing, and the obtained wire is obtained. A short-axis material (referred to as a slug) cut into an appropriate length, and if necessary, can be formed by press forming (cold clogging forging) in the processing annealing, and the cylindrical electrode can be formed by press forming. It is easier to make the plate of the end plate portion of the tubular electrode thicker than the tubular portion, and it is easy to integrally form the concave portion for positioning the body in the end plate portion, which is excellent in productivity. Further, the processing annealing can be performed at 800 to 950 ° C. Keep left and right for 3 minutes to 3 /J Since Nb is easily oxidized and nitrided, The annealing environment is preferably carried out in a vacuum atmosphere or an inert gas atmosphere such as argon. The above-mentioned "800 to 950 °C" means (: above, below 950 °C. Below, "N1 (number) ~ N2 (number)", N 1 or more and N 2 or less. Next, a description will be given of a fluorescent discharge tube and an electrode thereof according to an embodiment of the present invention. Fig. 1 is a view showing a portion of the fluorescent discharge tube of the embodiment. The tube includes a glass tube 1 in which a fluorescent film 8 is formed on the inner wall surface, and a gas for gas (a rare gas such as argon gas or mercury vapor) is sealed; and one pair of the opposite ends of the glass tube 1 constitutes a cold cathode Electrode 2 The electrode 2 is integrally formed of a tube portion 3 whose one end is open, and an end plate portion 4 which is closed at one end of the tube portion. The end plate portion 4, the rod-shaped electric conductor 5 for power supply and the tube The portions 3 are arranged in a concentric sheet. The above-mentioned sheets are obtained as described above, and when they are obtained, the thickness is made conductive. (Ar) 800 is referred to as a figure, and is placed and placed so that the square π 1351710 is formed. The conductor positioning portion 6 to which one end of the conductor 5 can be fitted. The conductor 5 is The end portion of the glass tube 1 is sealed inside and outside, and is sealed at the inner end portion of the glass tube 1 at the outer peripheral portion of the concave portion at the boundary with the end plate portion 4, and is welded by laser welding, electric resistance welding or the like. The other end of the conductive material located outside the glass tube 1 is connected to the power supply lead 7. The thickness of the end plate portion 4 (the thickness of the portion where the electric conductor 5 is welded must be formed to be thicker than the tube wall thickness of the tube portion 3). Thicker, the front portion 6 is formed, and the conductor 5 can be sufficiently welded to the end plate portion 4. In the small photodischarge tube, the length of the electrode 2 is about 4 to 10 mm, and the wall of the tube portion 3 is formed to be 0.08~ 0. 2 mm or so, the thickness of the end plate portion 4 is about 3 to 10 times the thickness of the pipe portion 3. Further, the depth of the concave portion of the end plate portion 4 is preferably equal to or greater than the wall thickness of the tube portion 3, preferably twice the tube wall thickness, and the wall thickness of the bottom surface of the concave portion 6 and the inner surface of the tube portion side is the wall of the tube. More than the thickness. The electrode 2 is formed of the above-described alloy for a Ni-Nb electrode. With the aforementioned Ni-Nb alloy, it has good cold formability, and its sputtering can be reduced compared with pure Ni, which can improve the life of the lamp. This cylindrical electrode can be integrally formed by molding. In the above embodiment, the conductor positioning recessed portion 6 is shown as an example of the end plate portion 4. However, the recessed portion 6 is not necessarily intended to be formed by forming the recessed portion 6 to allow the conductor 5 to be formed. Since the electric tube portion 3 is arranged concentrically, the electrode 2 and the glass tube 1 can be easily disposed with the concave side 6 and the copper body 5 t) by sealing the glass tube 1 into a concentric shape. The concave thickness is the wall usage rate of the front part 6 and is also formed by press forming. The pole 2 is in the shape of a heart with 12 1351710, which prevents the non-uniformity of the discharge state, and can discharge and improve the life of the lamp. Of course, the fluorescent discharge tube electrode is not limited, and may be formed by deep drawing as shown in Fig. 3. Hereinafter, the present invention will be more specifically described by way of examples, and the invention is not limited thereto. (Example) Various Nb amounts of Ni-Nb alloys (4 kg) shown in Table 1 were melted at 1500 ° C, and cast pieces cast with each melt were hot forged at 1100 ° C. After that, the hot rolling is started at a rolling temperature of 110 ° C, and the hot rolled sheet of each Ni-Nb alloy and the hot rolled material of the hot rolled wire are annealed in a mixed gas of nitrogen and hydrogen (atmosphere). 2 hours). Then, the hot rolled sheet was cold rolled into a sheet having a sheet thickness of 0.15 mm. The hot rolled wire was cold-worked into a wire having an outer diameter of 1.7 ηηιηφ. The sample thus prepared was evaluated, and the sputtering rate was measured. The processability was evaluated by a press forming test forming test (Eriksson test). In the press forming test, the wire was cut into a 1.8 mm process annealing (in a vacuum environment, held at 900 ° C for 2 hours), and then actually formed into a diameter of 5.4 mm and an outer diameter of 5.4 mm as shown in FIG. The body positioning was performed with a cylinder having a recess depth of 0.2 mm. The punch used for the forming die is the outer diameter 1. The opening angle of the end is 150°, and the material is the die steel (JIS specification, on the other hand, the inner diameter of the die is stabilized by the super hard alloy, Stamping becomes a bottomed cylinder, but this vacuum induces heat in the atmosphere. This is equal to 90 ° C, processed into a wire, processed, and deep drawn, using 1. 7 mm φ '-electrode and 5 mm φ ' front SKD 1 1 ) ° (D type 6 13 1351710). The stamping formability evaluation is based on the following criteria: when the number of forming times reaches 1000 times, the die is not broken, the punch is not deformed, and the mold can be continuously formed, and it is rated as AA; it can be formed more than 500 times, but it is achieved. Before 1000 times, the die has been damaged or the punch has been deformed, so that it can not be formed, it is rated as A; before the 500 times, the die has been damaged or the punch has been deformed, so that it cannot be formed. For B. Preferably, it is practically possible to form more than 500 times, that is, the aforementioned AA or A. In the deep drawing forming test, the sheet was cut into 100 mm squares and subjected to work annealing (under a vacuum atmosphere at 900 ° C for 2 hours), and then subjected to an Eriksson test in accordance with JIS B7729 and 7777. In the Erikson test, the surface of the sample was pressed by a spherical punch with a diameter of 20 mm at an extrusion speed of 5 to 20 mm / mi η until the crack was generated, and the surface of the sample was measured. The moving distance of the front end of the punch until the crack occurs (called the Erickson value. Unit: mm). If the Erickson value is 10 or more, the pull-in property is good, and it is a practically problem-free level. Further, the sputtering rate was measured by the following procedure. A test piece (10 mm x 10 mm) was taken from the aforementioned N i - N b alloy sheet, and the test surface was mirror-polished. An ion beam apparatus (Veeco Co., Ltd., model: VE-747) was used to apply a voltage (500 V) between the target and the substrate, and the test surface was subjected to argon ions (1·3 χ 10_6 Torr) for a certain period of time ( 120min) accelerated stamping and sputtering. A part of the mirror surface was covered on the test surface to form a non-sputtering portion, and after sputtering, a height difference was formed between the sputtering portion formed by cutting off the mirror surface portion of the test piece and the non-sputtering portion covered by the sputtering. The height difference was measured by a contact 14 1351710 type roughness meter (manufactured by Sloan Co., Ltd., type: DEKTAK2A), and the sputtering rate (A/min) was determined by the following formula. Further, the sputtering rate of each sample was divided by pure Ni (sample No. 1), and the relative storage ratio was determined. These measured values are shown together in Table 1. Further, a graph in which the relationship between the amount of Mb and the relative sputtering rate is plotted is shown in Fig. 4 . Sputtering rate = height difference (A) / sputtering time (120 min) [Table 1] Sample N 〇. Nb amount % South difference A sputtering rate A/mi η relative sputtering rate % press forming Erikson Value mm Remark 1 0.0 29443 245. 4 100 ΑΑ 11.3 Convention 2 2. 0 28267 235.6 96. 0 ΑΑ 10.3 Invention Example 3 3. 1 27928 232. 7 94. 9 A 10.4 Invention Example 4 5. 0 2781 6 231.8 94. 5 A 10.6 Inventive Example 5 7. 0 28822 240. 2 97. 9 B 6.8 Comparative Example 6 9. 0 28928 241. 1 98. 3 B 6. 7 Comparative Example 7 11.0 28951 241.3 98. 3 B 6. 6 Comparative Example It can be seen from Tables 1 and 4 that the sample of the invention example N 〇. 2 to N 〇. 4 has a relative irradiance of 96% or less, and the effect of reducing the sputtering by N b is confirmed, and the press forming is confirmed. The level of practicality of deep and deep drawability is also confirmed. On the other hand, as shown in Fig. 4, the sample No. 5 to N 〇. 9* in which the amount of Nb exceeds 6% is increased by the addition of Nb, and the sputtering rate is deteriorated, and the sputtering rate is deteriorated. And the formability is also deteriorated. 15 1351710 BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a cross-sectional view of an essential part of a fluorescent discharge tube including a fluorescent discharge tube electrode according to an embodiment of the present invention. Fig. 2 is a cross-sectional view showing the electrode of the fluorescent discharge tube which is press-formed in the embodiment of the present invention. Fig. 3 is a cross-sectional view showing an essential part of a fluorescent discharge tube having a conventional fluorescent discharge tube electrode. Fig. 4 is a graph showing the relationship between the amount of Nb added and the relative sputtering rate in the examples. [Description of main components] 1 Glass tube 2 Electrode 3 Tube part 4 End plate part 5 Conductor 6 Conductor positioning recess 7 Power supply lead 8 Fluorescent film 11 Glass tube 12 Electrode 13 Tube part 14 End plate part 15 Conductor 17 wire 16