1360526 九、發明說明 【發明所屬之技術領域】 本發明係關於板玻璃之製造方法，板玻璃之緩衝層形 成裝置及板玻璃之製造設備，尤其關於使用浮式法之板玻 芳二i ?乏爽隽 SAM 造設—_______________ 【先前技術】 於依據浮式法之板玻璃之製造方法中，首先連續地供 應熔融玻璃至收納有熔融金屬之浴槽的水平浴面而形成玻 璃帶，接著將玻璃帶從熔融金屬浴槽出口予以上拉而往熔 融金屬浴槽外拉出。藉由從浴槽的出口將玻璃帶予以上拉 之延伸力，而成形爲目標的厚度。接下來，於移出滾輪上 搬運玻璃帶並搬入至徐冷爐，於徐冷爐內一邊搬運一邊進 行徐冷。之後將玻璃帶裁切爲特定長度而藉此製造出板玻 璃。 上述浮式法，係藉由熔融金屬的浴面而形成板玻璃的 一面，並且使熔融玻璃於熔融金屬上擴展而藉此形成另一 面之自由面，因此，板玻璃的平坦度極高，並且亦成爲適 用於大量生產之方法。因而適用於汽車用玻璃、建築用玻 璃、電漿顯示器用玻璃及液晶顯示用玻璃等之生產。 於浮式法中，爲了防止因玻璃的急遽收縮所造成之破 裂或平坦度的降低，必須將移出滾輪上所搬運之高溫的玻 璃帶，於後段的徐冷爐內一邊控制冷卻速度一邊進行徐冷 。因此，徐冷爐的長度有時會達到數百公尺之規模。此外 -4- !360526 ’於徐冷爐中’玻璃帶係一邊於搬運滾輪等的上方被搬運 —邊進行徐冷，但有時因玻璃帶與搬運滾輪等的接觸，而 具有在玻璃表面上產生疵點之疑慮。 爲了防止此疵點的產生，以往係將二氧化硫（so2) 導入至徐冷爐內部，於高溫的玻璃表面上使玻璃與S〇2反 應’而在玻璃表面上形成例如由硫酸鈉（Sodium Sulfate ;Na2S04 )或亞硫酸鈉（Sodium Sulfite ; Na2S03 )等所 形成之緩衝層，並藉由此緩衝層來抑制因玻璃與搬運滾輪 等的接觸所造成之疵點的產生（參照專利文獻1 )。 專利文獻1:日本特開平2-14841號公報 【發明內容】 (發明所欲解決之課題） 然而，由於S02爲腐蝕性極高之氣體，若將S02導入 至徐冷爐內部，則會導致徐冷爐內部的設備被腐蝕，而產 生徐冷爐的耐久性大幅降低之問題。 此外，液晶顯示用的板玻璃，由於必須在表面形成液 晶顯示元件的電路，因此係採用幾乎不包含在電路形成時 會造成不良影響之鹼金屬之組成的無鹼玻璃。於以浮式法 製造無鹼玻璃時，即使於徐冷爐內與3 02氣體接觸，由於 幾乎不包含鹼金屬，因此難以形成由硫酸鈉或亞硫酸鈉等 所形成之緩衝層，而導致無法防止因與搬運滾輪等的接觸 所造成之疵點的產生之問題。 再者，爲了進行玻璃板的生產管理，係於玻璃製造裝 [S3 -5- 1360526 置的下游設置有缺失檢測器，因此，乃要求〜種^#弓丨 此缺失檢測器的錯誤動作之緩衝層。 本發明係鑒於上述情況而創作出之發明，目 供一種可抑制疵點的產生之板玻璃之製造方法，板玻璃 寧_衝-辱形成裝置及板玻璃之製填s受備，來取代以往使 S〇2之緩衝層的形成手段。 (用以解決課題之手段） 爲了達成上述目的，本發明係採用以下構成。 本發明之板玻璃之製造方法，爲具備：連續地供應 融玻璃至收納有熔融金屬之溶融金屬浴槽的水平浴面而 成玻璃帶之成形製程；及將前述玻璃帶搬運至徐冷爐而 行徐冷之徐冷製程之板玻璃之製造方法，其特徵爲：於 述成形製程後的製程中，係於前述玻璃帶的下表面，使 點產生防止劑帶電而形成由疵點產生防止劑所形成之緩 層。 此外，於本發明之板玻璃之製造方法中，前述緩衝 較理想係由靜電塗裝法所形成。 再者，於本發明之板玻璃之製造方法中，較理想爲 前述成形製程後的製程中，配置有於前述玻璃帶的下表 側形成前述緩衝層之形成手段；前述形成手段係由：配 於前述玻璃帶的下表面側之帶電電極；及收納有前述帶 電極且以流動狀態保持前述疵點產生防止劑，並且於前 玻璃帶側具有開口部之帶電化保持容器所構成；係藉由 起 提 之 用 熔 形 進 前 疵 衝 層 於 面 置 電 述 刖 [S3 -6- 1360526 述帶電電極使前述疵點產生防止劑帶電，並且使前述疵點 產生防止劑從前述帶電化保持容器的開口部往前述玻璃帶 的方向流動。 此外，於本發明之板玻璃之製造方法中，較理想爲於 前述成形製程後的製程中，配置有於前述玻璃帶的下表面 側形成前述緩衝層之形成手段；前述形成手段係由：配置 於前述玻璃帶的下表面側，保持帶電狀態與流動狀態的前 述疵點產生防止劑，並且於前述玻璃帶側具有開口部之保 持容器；具有帶電電極與收納有前述帶電電極且以流動狀 態保持前述疵點產生防止劑之帶電化保持容器之帶電化裝 置；及從前述帶電化裝置將帶電狀態的前述疵點產生防止 劑供應至前述保持容器之供應管所構成；係藉由前述帶電 電極使前述疵點產生防止劑帶電，且經由前述供應管將帶 電狀態的前述疵點產生防止劑供應至前述保持容器，並且 使前述疵點產生防止劑從前述保持容器的開口部往前述玻 璃帶的方向流動。 此外，於本發明之板玻璃之製造方法中，較理想爲於 隔著前述玻璃帶與前述形成手段相對向之位置上，配置拉 出電極；藉由前述拉出電極，將帶電狀態的前述疵點產生 防止劑朝向前述玻璃帶的下表面導引，藉此使前述疵點產 生防止劑附著於前述下表面，而形成前述緩衝層。 再者，於本發明之板玻璃之製造方法中，較理想爲前 述疵點產生防止劑，爲從由鹼金屬或鹼土類金屬的硫酸鹽 、鹼金屬或鹼土類金屬的氯化物鹽、鹼金屬或鹼土類金屬 IS] -7- 1360526 的碳酸鹽、氧化物陶瓷、氮化物陶瓷、及金屬硫化物所組 成之群組中所選擇之1種以上的粉體。 * 接著，本發明之板玻璃之緩衝層形成裝置’爲設置於 • 板玻璃之製造設備中之板玻璃之緩衝層形成裝置’此板玻 • 璃_多製造_設備係具備：收納有熔融金屬，且於前述熔融金 . 屬的水平浴面連續地供應有熔融玻璃而形成玻璃帶之熔融 金屬浴槽；及對前述玻璃帶進行徐冷之徐冷爐，其特徵爲 Φ :於前述熔融金屬浴槽後的製程中，係於前述玻璃帶的下 表面，使疵點產生防止劑帶電而形成由疵點產生防止劑所 形成之緩衝層。. 接著，本發明之板玻璃之製造設備，爲具備：收納有 熔融金屬，且於前述熔融金屬的水平浴面連續地供應有熔 融玻璃而形成玻璃帶之熔融金屬浴槽；及對前述玻璃帶進 行徐冷之徐冷爐之板玻璃之製造設備，其特徵爲：係具備 先前所記載之板玻璃之緩衝層形成裝置而成。 發明之效果： 根據本發明，係能夠提供一種可抑制疵點的產生之板 • 玻璃之製造方法，板玻璃之緩衝層形成裝置及板玻璃之製 . 造設備’來取代以往使用so2之緩衝層的形成手段。 亦即’根據本發明之板玻璃之製造方法，於成形製程 後的製程中’係於玻璃帶的下表面形成有由疵點產生防止 劑所形成之緩衝層，因此不會產生疵點產生防止劑擴散至 徐冷爐內部之疑慮，且即使產生擴散，由於未使用腐蝕性 -8- 1360526 的氣體，因此可防止徐冷爐內之設備的劣化。再者，即使 玻璃帶的下表面接觸於搬運滾輪等，亦可藉由玻璃帶的下 表面所形成之緩衝層，來防止疵點的產生。 此外，於本發明之板玻璃之製造方法中，於以靜電塗 _參_竺赉座_緩__-_層_時二—可_不_1到！璃」袓成之左右來形成緩衝 層，即使如液晶顯示用的板玻璃般之無鹼玻璃，亦可形成 緩衝層而防止疵點的產生。再者，爲了進行玻璃板的生產 管理，係於玻璃製造設備的下游裝設有缺失檢測器，但由 於可在玻璃帶的下表面大致呈一致地形成緩衝層，因此可 防止此缺失檢測器的錯誤動作。 緩衝層的形成方法並不限定於靜電塗裝法，只要爲可 有效率地使疵點產生防止劑帶電而於玻璃帶的下表面形成 緩衝層之方法即可，例如亦可使用靜電噴霧法。 再者，於本發明之板玻璃之製造方法中，於使用由配 置於玻璃帶的下表面側之帶電電極；及收納有帶電電極且 以流動狀態保持疵點產生防止劑，並且於玻璃帶側具有開 口部之帶電化保持容器所構成之形成手段時，由於使疵點 產生防止劑成爲流動狀態而使該疵點產生防止劑於玻璃帶 的下表面側帶電，因此，可有效率地使疵點產生防止劑帶 電，並迅速地使帶電的疵點產生防止劑附著於玻璃帶而形 成緩衝層，提升緩衝層的形成效率並完整地於下表面全面 形成緩衝層。 此外，於本發明之板玻璃之製造方法中，於使用由保 持帶電狀態的疵點產生防止劑之保持容器；具有帶電電極 ί S3 -9- 1360526 與帶電化保持容器之帶電化裝置：及供應管所構成之形成 手段時，係由帶電化裝置使疵點產生防止劑成爲流動狀態 且有效率地帶電，並將此供應至供應管，藉此，可提升緩 衝層的形成效率並完整地於下表面全面形成緩衝層。此外 1 將帶電化裝置配置於徐冷爐的外部，此時，係使疵點 產生防止劑於徐冷爐的外部帶電，並將帶電狀態的疵點產 生防止劑供應至玻璃帶的下表面，因此可容易進行疵點產 生防止劑的補給並提高生產性。 此外，於本發明之板玻璃之製造方法中，於隔著玻璃 帶與形成手段相對向之位置上配置拉出電極時，係藉由拉 出電極1 2將帶電狀態的疵點產生防止劑朝玻璃帶的下表 面導引，因此，可使緩衝層一致地形成於下表面的全面， 即使玻璃帶的下表面接觸於徐冷爐的搬運滾輪，亦可藉由 緩衝層來防止疵點的產生。 再者，於本發明之板玻璃之製造方法中，由於前述疵 點產生防止劑，爲從由鹼金屬或鹼土類金屬的硫酸鹽、鹼 金屬或鹼土類金屬的氯化物鹽、鹼金屬或鹼土類金屬的碳 酸鹽、氧化物陶瓷、氮化物陶瓷、及金屬硫化物所組成之 群組中所選擇之1種以上的粉體，因此不會腐蝕徐冷爐內 部的設備。 接著，根據本發明之板玻璃之緩衝層形成裝置，於成 形製程後的製程中，係於玻璃帶的下表面形成有由疵點產 生防止劑所形成之緩衝層，因此不會產生疵點產生防止劑 擴散至徐冷爐內部之疑慮，且即使產生擴散，由於未使用 [S3 -10- 1360526 腐蝕性的氣體，因此可防止徐冷爐內之設備的劣化。 此外，由於可不受到玻璃組成之左右來形成緩衝層， 因此，即使如液晶顯示用的板玻璃般之無鹼玻璃，亦可形 成緩衝層而防止疵點的產生。 再者，爲了進行玻璃板的生產管理，係於玻璃製造設 備的下游裝設有缺失檢測器，但亦可防止此缺失檢測器的 錯誤動作。 此外，根據本發明之扳玻璃之製造設備，由於具備上 述緩衝裝置，因此，不僅可防止徐冷爐內之設備的劣化， 並且可不受到玻璃組成之左右來形成緩衝層，而防止疵點 的產生。再者，爲了進行玻璃板的生產管理，係於玻璃製 造設備的下游裝設有缺失檢測器，但亦可防止此缺失檢測 器的錯誤動作。 【實施方式】 以下係參照圖式，說明本發明的實施型態。於以下說 明中所參照之圖式，爲用以說明本實施型態之板玻璃之緩 衝層形成裝置及板玻璃之製造設備的構成，圖式中所表示 之各部的大小、厚度及尺寸等，係與實際的緩衝層形成裝 置及製造設備之尺寸關係有所不同。 「第1實施型態」 以下係說明本發明的第1實施型態。第1圖係顯示本 實施型態之板玻璃之製造設備的一部分之剖面模式圖，第 -11 - 1360526 2圖係顯示板玻璃之製造設備中所具備之緩衝層形成裝置 之立體圖，第3圖係顯示板玻璃之製造設備中所具備之緩 衝層形成裝置之側視圖，第4圖係顯示緩衝層形成裝置的 特取部分之立體圖，第5圖係顯示緩衝層形成裝置的特取 部兮夸正視.圖。 第1圖所示之板玻璃之製造設備，係設置於用以調製 熔融玻璃且予以清澄化之熔解清澄槽（圖式中省略）的後 段，且大致由：收納有熔融金屬la之熔融金屬槽1;設置 於熔融金屬槽1的後段之搬運室2;及設置於搬運室2的 後段之徐冷爐3所構成。於徐冷爐3的入口 3 a附近，設 置有本發明之緩衝層形成裝置4。此外，於徐冷爐3的後 段，具備用以檢察玻璃帶的表面之圖式中省略的缺失檢測 器，以及將冷卻後的予以裁切之圖式中省略的裁切機。 於熔融金屬槽1中，係注滿由金屬錫等所構成之熔融 金屬1 a，且熔融玻璃5連續地從熔解清澄槽（圖式中省略 ，以下亦同）供應至此熔融金屬la的浴面1B上而構成。 於搬運室2中具有移出滾輪2a，並藉由移出滾輪2a 的牽引力，從熔融金屬槽1當中將成形爲板狀之玻璃帶6 予以拉出而構成。 此外，於徐冷爐3中具有層滾輪3b，並且於徐冷爐3 內，藉由層滾輪3b將從搬運室2所搬運來之玻璃帶6予 以搬運而構成。 於熔解清澄槽中所熔融之溶融玻璃5，係連續地從熔 解清澄槽供應至熔融金屬槽1之熔融金屬la的浴面1B上 rsi -12- 1360526 . ，將熔融玻璃5成形爲期望的厚度及寬度後’藉由移出滾 輪2a的牽引力，從熔融金屬槽1的出口予以拉出。此時 ' ，熔融玻璃5係調整至可進行塑性變形之溫度而成爲玻璃 • 帶6。成形後的玻璃帶6’係通過搬運室2且被搬運至徐 • 冷爐3，於通過徐冷爐3內部時，進行緩慢的冷卻。此時 ________ _— - — — -·- - - - - — · ~ - - . ，係藉由徐冷爐3的入口 3a上所設置之緩衝層形成裝置4 ，於玻璃帶6的下表面6a形成疵點產生防止用的緩衝層 於本實施型態中，係說明將緩衝層形成裝置設置於徐 冷爐的入口 3a之情況，但只要位於熔融金屬浴槽1之後 的製程即可，例如可設置於搬運室2。就玻璃帶的疵點防 止之觀點來看，較理想爲盡可能設置於熔融金屬浴槽1的 直接下游，但較理想爲設置於玻璃狀態較爲安定之徐冷爐 3的入口（以下，於實施型態2中亦相同）。 φ (緩衝層形成裝置） 接著參照第2圖~第5圖，說明本發明之緩衝層形成 裝置4的一例。第2圖及第3圖所示之緩衝層形成裝置4 • ，係由：配置於玻璃帶6的下表面6a側，且以帶電狀態 . 與流動狀態保持疵點產生防止劑之疵點產生防止劑的形成 裝置1 1 (形成手段）；及隔著玻璃帶6而配置於與形成裝 置11相對向之位置之拉出電極12所構成。第2圖〜第5 圖所示之形成裝置11 (形成手段），係於玻璃帶6的下表 面6a側，使疵點產生防止劑帶電。 { S] -13- 1360526 拉出電極12係形成爲俯視大致呈矩形狀之板狀的電 極’且以該長度方向與玻璃帶6的寬度方向Η呈一致之方 式地配置。此外，拉出電極12之沿著長度方向的長度， 係設定爲與玻璃帶6的寬度相同或是較玻璃帶6的寬度還 兔二贽出—里®jm由__配線—12上二連接於垮冷琴—」的外帮 上所設置之圖中未顯示的高電壓電源裝置，或者是接地。 此外’疵點產生防止劑的形成裝置11，係由：配置於 玻璃帶6的下表面6a側之帶電電極13;及收納有帶電電 極1 3且以流動狀態保持疵點產生防止劑μ，並且於玻璃 帶6側具有開口部1 4e之帶電化保持容器〗4所構成。 如第2圖、第3圖及第5圖所示，帶電電極13係由 :沿著玻璃帶6的寬度方向延伸之電極本體13a;及從電 極本體1 3 a朝上側（玻璃帶6側）突出之複數個針狀電極 1 3 b所構成。針狀電極1 3 b互相形成等間隔而配置。帶電 電極13的材質，較理想以於700 °C不會產生變形且不會氧 化之耐熱材料所形成，例如較理想爲不銹鋼合金、鎳或鎳 合金等。此外，針狀電極1 3 b之相互的間隔，例如可於玻 璃帶6的寬度之每l〇cm的寬度具有1個之比例來設置。 帶電電極13的形狀並不需爲本實施型態之形狀，只要能 夠有效率地使疵點產生防止劑Μ帶電，則形狀並無特別限 定。 於電極本體13a的一端側連接有配線13c，帶電電極 1 3係經由此配線1 3 c，連接於徐冷爐3的外部上所設置之 圖中未顯示的高電壓電源裝置。 ^ -14- 1360526 接著如第2圖〜第4圖所示，帶電化保持容器14係由 :容器本體14a;及豎設於容器本體14a的內部之一對的 間隔壁部Mb所構成。容器本體14a的內部空間，係由一 對的間隔壁部1 4 b而區隔爲3個空間。亦即，於容器本體 14a二係形成有位於間隔壁部彼此之間之帶電化室14C;及 夾介間隔壁部1 4 b而配置於帶電化室1 4 c的兩側之回收室 I4d。帶電化室l4c及回收室Md，係以沿著玻璃帶6的移 動方向 L依序排列回收室 Md、帶電化室14c、回收室 14d之方式地配置。此外，於容器本體Ma之與玻璃帶6 相對向的位置，設置有開口部1 4e，且成爲帶電電極1 3仰 望玻璃帶6的下表面6a之形式。 此外，於帶電化室14c中，係具備設置有僅可讓氣體 通過之程度的細孔而成之整流構件1 4 f，位於較整流構件 1 4f上側之部分，係構成以帶電狀態與流動狀態保持疵點 產生防止劑Μ之帶電•流動部14cl，位於較整流構件I4f 下側之部分，係構成爲了使疵點產生防止劑Μ成爲流動狀 態而使氣體朝帶電·流動部1 4 c 1噴出之氣體導入部1 4 c 2 。於帶電·流動部14cl中，帶電電極13係配置於整流構 件14f的上方。此外，於氣體導入部14c2係裝設有氣體 導入配管1 4g。再者，於帶電·流動部1 4c 1係裝設有供應 疵點產生防止劑Μ之供應裝置（圖式中省略）。供應裝置 例如有螺旋輸送機。 供應至帶電·流動部1 4c 1之疵點產生防止劑Μ，較 理想爲可附著於玻璃帶6而產生緩衝作用，於高溫下容易 [S] -15- 1360526 形成流動狀態，容易帶電且不會凝聚成粗大的粒子，不會 與玻璃引起化學反應並容易洗去，並且不會腐蝕徐冷爐3 內部的設備者，較理想例如爲從由鹼金屬或鹼土類金屬的 硫酸鹽、驗金屬或驗土類金屬的氯化物鹽、鹼金屬或驗土 類金！的碳酸鹽、氧化物陶瓷、氮^化物陶瓷、及金屬硫化 物所組成之群組中所選擇之1種以上的粉體，更理想爲芒 硝（硫酸鈉的十水合物）或是碳酸鈉的粉體。疵點產生防 止劑Μ的平均粒徑，較理想例如爲20μιη以下，只要可讓 疵點產生防止劑Μ —致地附著於玻璃帶6，則粒度並無特 別限制。 此外，藉由容器本體14a中所設置之開口部14e，使 帶電.流動部1 4c 1及回收室1 4d於玻璃帶6的下表面6a 側開放。此外’於各個回收室1 分別具有氣體導出配管 14h，並構成爲將從帶電·流動部14c 1噴出且回收至回收 室14d之包含疵點產生防止劑Μ之導入氣體，排出至容器 本體1 4 a的外部。 由於帶電化保持容器14係設置在環境溫度爲700 °C左 右之徐冷爐3的入口附近’因此，構成帶電化保持容器14 之容器本體14a、間隔壁部14b及整流構件14f等構件， 較理想均以具有耐熱性之材料所構成。此外，由於在帶電 化保持容器14中收納有連接於高電壓電源裝置之帶電電 極13，因此，容器本體14a、間隔壁部14b及整流構件 1 4 f等構件，較理想均以具有絕緣性之材料所構成。滿足 耐熱性及絕緣性之材料’例如有以石英玻璃或二氧化鋁系 1360526 陶瓷所代表之各種耐熱性陶瓷。 帶電電極13及帶電電極用的配線13c，較理想爲對帶 電化保持容器14的構件或徐冷爐3內部的設備形成絕緣 。於帶電電極13及其配線13c未充分絕緣時，會於未絕 轉之處_產_生放電，尹於設置有帶電化保1夸器1 4之環境 爲數百°C之高溫環境，因此，即使僅爲些許絕緣不良，亦 容易引起放電。關於絕緣對策，較理想爲盡可能不使金屬 構件接近於徐冷爐3內部的配線13c。此外，配線13c較 理想係以耐熱•耐絕緣性材料所被覆。再者，爲了防止來 自配線1 3 c與帶電電極1 3的接觸處之放電，如第1圖、 第4圖或第5圖所示，較理想於帶電化保持容器14的側 壁部設置由絕緣材料所構成之管筒1 4i，將帶電電極用的 配線13c插入於此管筒14i，於容器本體14a內予以連接 ，並以不會產生放電之方式，部分地以滿足耐熱性及絕緣 性之材質予以被覆。管筒14i的材質，與帶電化保持容器 1 4的構成材料相同，可使用滿足耐熱性及絕緣性之材料。 接下來詳細說明回收室1 4d »回收室1 4d係藉由間隔 壁部14b與帶電化室14c區隔。此間隔壁部14b的上端部 14bl，係位於較容器本體14a的上端部14al更下側。藉 此，於從帶電化室1 4 c所供應之疵點產生防止劑Μ的一部 分未附著於玻璃帶6而飛散至周圍時，可藉由容器本體 14a的上端部14a 1將飛散的疵點產生防止劑Μ予以擋住 ，而成爲可回收至回收室14d之形式。 此外，於回收室14d，係裝設有用以吸引回收室I4d [Si! -17- 1360526 內的環境氣而取出之氣體導出管14h。藉此，可將回收至 回收室14d之疵點產生防止劑Μ，排出至帶電化保持容器 14及徐冷爐3的外部。藉由將上述構成的回收室14d設置 於帶電化室14c的兩側，可防止疵點產生防止劑Μ飛散至 t余冷爐3的內部，而防止疵點產生防止劑Μ對徐冷爐3內 造成污染，此外並可再生利用取出至外部的疵點產生防止 劑Μ。 若帶電化保持容器1 4的開口部1 4e與玻璃帶6之間 的距離太近，則會產生於玻璃帶6撓曲時，玻璃帶6可能 接觸於帶電化保持容器14之疑慮，此外，若開口部14e 與玻璃帶6之間的距離太遠，則會產生疵點產生防止劑Μ 可能從開口部1 4e與玻璃帶6之間飛散出，而污染徐冷爐 3內部之疑慮。因此，帶電化保持容器14可在不會接觸於 玻璃帶6之程度下接近於玻璃帶6而設置，例如可將帶電 化保持容器14的開口部1 4 e與玻璃帶6之間的距離設定 爲2〜5 c m。 接著參照第6圖，說明於玻璃帶6形成緩衝層之方法 〇 首先，將疵點產生防止劑Μ供應至帶電化保持容器 1 4的帶電•流動部1 4c 1。之後，從氣體導入配管1 4g例 如將乾燥空氣或氮氣等（以下亦稱爲乾燥空氣等）供應至 氣體導入部14c2。亦可以不會對徐冷爐3內部的溫度造成 影響之方式’加熱乾燥空氣等之後再導入。供應至氣體導 入部14c2之乾燥空氣等，係通過整流構件14f而從整流 [S] -18- 1360526 構件14f的上面全面一致地噴出至帶電·流動部Mcl。藉 由此噴出後的乾燥空氣等，使由粉體所構成之疵點產生防 止劑飛舞，而使疵點產生防止劑Μ成爲流動狀態》 此時，藉由將電力供應至帶電電極13，使疵點產生防 止^劑^ Μ例_如帶負電。_帶電條件係因疵點產生防止劑Μ的 種類、欲形成之緩衝層的厚度、及每單位時間的塗佈量而 有所改變，但較理想例如設定爲10kV以上、ΙΟΟμΑ以上 〇 帶電後的疵點產生防止劑Μ，係藉由針狀電極1 3b朝 玻璃帶6的下表面6a導引。此外，帶電後的疵點產生防 止劑Μ，亦可藉由拉出電極12朝玻璃帶6的下表面6a導 引。此外，玻璃帶6本身大致爲帶正電。藉由上述方式， 可使疵點產生防止劑Μ —致地附著於玻璃帶6的下表面 6a，如第6圖所示，而在玻璃帶6的下表面6a形成緩衝 層B。 於藉由乾燥空氣等而在帶電·流動部1 4c 1內成爲流 動狀態後，未帶電而未附著於玻璃帶6之疵點產生防止劑 Μ，以及雖然帶電但未附著於玻璃帶6之疵點產生防止劑 Μ，係落下至回收室i4d，並經由氣體導出配管14h與乾 燥空氣等一同取出至帶電化保持容器14的外部。藉此可 降低徐冷爐3內部的污染。此外，取出至外部之疵點產生 防止劑Μ，可藉由過濾器予以捕集而進行再利用。 藉由形成於玻璃帶6的下表面6a之緩衝層Β，即使 用以搬運玻璃帶6之層滾輪3b接觸於玻璃帶6的下表面 -19- 1360526 6a，亦可因緩衝層B的存在而防止玻璃帶6之疵點的產生 。此外，由於緩衝層B本身僅藉由靜電效果而附著，因此 容易藉由水洗等而予以洗淨。因此，並不會產生緩衝層B 對板玻璃的品質造成影響之疑慮。 如以上所說明般，根據本實施型態，由於係藉由靜電 塗裝法將由疵點產生防止劑Μ所構成之緩衝層B形成於 玻璃帶6的下表面6a，因此，並無疵點產生防止劑Μ於 徐冷爐3內部飛散之疑慮，因此可防止徐冷爐3內之設備 的劣化。此外，由於係藉由所謂的靜電塗裝法，使帶負電 的疵點產生防止劑Μ附著於帶正電的玻璃帶6而形成緩衝 層Β，因此不會受到玻璃組成的限制而能夠形成緩衝層Β ，藉此，即使如液晶顯示用的板玻璃般之無鹼玻璃，亦可 形成緩衝層Β而防止疵點的產生。 此外，係將帶電化保持容器14配置於玻璃帶6的下 表面6a側，且將拉出電極12配置於與帶電化保持容器14 相對向之位置，並藉由拉出電極1 2將帶電狀態的疵點產 生防止劑Μ朝玻璃帶6的下表面6a導引，並使疵點產生 防止劑Μ附著於下表面6a而形成緩衝層B，因此，可使 緩衝層B —致地形成於下表面6a的全面，即使玻璃帶6 的下表面6a接觸於徐冷爐3的層滾輪3b，亦可藉由一致 地形成於下表面6a的全面之緩衝層B，防止玻璃帶6之 疵點的產生。此外，由於玻璃帶6本身爲帶正電，因此， 雖然在不具備拉出電極12時，亦可藉由乾燥空氣等的流 動將帶負電的疵點產生防止劑Μ導引至玻璃帶側而能夠形 ί S] -20- 1360526 成緩衝層B，但具備拉出電極12者，可更有效率地形成 緩衝層B。 再者，由於係在玻璃帶6的下表面6a側使疵點產生 防止劑Μ帶電，因此可迅速地使帶電的疵點產生防止劑μ 附著於玻璃帶6而形成緩衝層Β，提升緩衝層Β的形成效 率並完整地於下表面6a全面形成緩衝層Β。 此外，根據本實施型態，由於可藉由回收室14d及氣 體導出配管14h將未附著的疵點產生防止劑Μ排出至徐冷 爐3的外部，因此，徐冷爐3的內部不會受到疵點產生防 止劑Μ的污染，此外，亦可將疵點產生防止劑μ予以再 利用。 「第2實施型態」 接著參照第7圖及第8圖，說明第2實施型態之緩衝 層形成裝置24。於第7圖及第8圖所示之構成要素當中， 對於與第1圖〜第6圖中所說明之構成要素爲同一構成要 素，係附加同一圖號並省略或簡化該說明。 第7圖所示之緩衝層形成裝置24，係由：於玻璃帶6 的下表面6a側以帶電狀態保持疵點產生防止劑Μ之疵點 產生防止劑Μ的形成裝置3 1 (形成手段）；及隔著玻璃 帶6而配置於與形成裝置31相對向之位置之拉出電極12 所構成。第7圖所示之形成裝置31 (形成手段），爲使疵 點產生防止劑Μ帶電，且將帶電狀態的疵點產生防止劑形 成於玻璃帶6的下表面6 a側。 [S3 -21 - 1360526 拉出電極12，與第1實施型態的拉出電極相同，係形 成爲俯視大致呈矩形狀之板狀的電極，並經由配線12a， 連接於徐冷爐3的外部上所設置之圖中未顯示的高電壓電 源裝置，或者是接地。 此外，疵點產生防止劑Μ的形成裝置31，大致係由 :配置於玻璃帶6的下表面6a側且保持帶電狀態的疵點 產生防止劑Μ之保持容器41;設置於徐冷爐3的外部之 帶電化裝置51;及從帶電化裝置51將帶電狀態的疵點產 生防止劑Μ供應至保持容器4 1之供應管6 1。於本實施例 中，係說明將帶電化裝置51設置於徐冷爐3的外部之形 成裝置3 1，但設置場所並無特別限定。於將帶電化裝置 5 1設置於徐冷爐的外部時，由於係在徐冷爐的外部使疵點 產生防止劑Μ帶電，並將帶電狀態的疵點產生防止劑Μ 供應至玻璃帶6的下表面側，因此容易進行疵點產生防止 劑Μ的補給並提高生產性，因而較爲理想。 如第7圖及第8圖所示，帶電化裝置5 1係由：中空 的容器本體53a;及配置於容器本體53a的內部之整流構 件5 3 b所構成。整流構件5 3 b爲設置有僅可讓氣體通過之 程度的細孔而成之構件。此外，容器本體5 3 a的內部空間 ，係由整流構件5 3 b而區隔爲2個空間。亦即，於容器本 體5 3 a，係區隔形成有位於整流構件5 3 b的上游側之帶電 •流動部5 1 c 1，及位於整流構件5 3 b的下游側之氣體導入 部 5 1 c 2。 帶電·流動部5 1 c 1，爲以帶電狀態與流動狀態保持疵 i S] -22- 1360526 點產生防止劑Μ者，氣體導入部51c2’爲使庇點產生防 止劑Μ成爲流動狀態而使氣體朝帶電·流動部5 k 1噴出 者。 於氣體導入部51 c2係裝設有氣體導入配管53d。此外 ，於帶電·流動部51cl中，係於整流構件53b的上方設 置有帶電電極52，且連接有將帶電狀態的疵點產生防止劑 Μ供應至保持容器41之供應管61。如第7圖及第8圖所 示，帶電電極52係由：幾乎於水平方向延伸存在之電極 本體52a;及從電極本體52a朝垂直方向豎設之針狀電極 5 2b所構成之大致呈L字狀成形之線狀電極。於第7圖及 第8圖中，針狀電極5 2b的前端部分係插入於供應管61 的內部。藉由此構成，可有效率地使疵點產生防止劑Μ帶 電。此外，並不需一定爲針狀電極52有效率地使疵點產 生防止劑Μ帶電’則並不限定於本構成及形狀。此外，帶 電電極52的材質’由於設置於徐冷爐3的外部，因此對 耐熱性並無特別要求，只要爲具有良好的帶電效率之材料 ，則並無特別限定。 於電極本體52a的一端側連接有配線52c，帶電電極 5 2係經由此配線52c，連接於圖中未顯示的高電壓電源裝 置》 再者，於帶電·流動部5 1 c 1係裝設有供應疵點產生 防止劑Μ之供應裝置（圖式中省略）。供應裝置例如有螺 旋輸送機。 供應至帶電·流動部5 1 c 1之疵點產生防止劑Μ，與 { S3 -23- 1360526 第1實施型態相同，較理想例如爲從由鹼金屬或鹼土類金 屬的硫酸鹽、鹼金屬或鹼土類金屬的氯化物鹽、鹼金屬或 鹸土類金屬的碳酸鹽、氧化物陶瓷、氮化物陶瓷、及金屬 硫化物所組成之群組中所選擇之1種以上的粉體，更理想 爲年J肖（硫酸鈉的十水合物）或是碳酸鈉的粉體。疵點產 — ' - - - - - - - . - _ -- 生防止劑Μ的平均粒徑，較理想例如爲2 0 μιη以下，只要 可讓疵點產生防止劑Μ —致地附著於玻璃帶6，則粒度並 無特別限制。 接著如第7圖所示，保持容器41係由：容器本體41a ;及豎設於容器本體4 1 a的內部之一對的間隔壁部4 1 b所 構成。容器本體41 a的內部空間，係由一對的間隔壁部 41b而區隔爲3個空間。亦即，於容器本體41a，係形成 有位於間隔壁部彼此之間之保持室4 1 c ;及夾介間隔壁部 4lb而配置於保持室41c的兩側之回收室41d。保持室41c 及回收室41d，係以沿著玻璃帶6的移動方向L依序排列 回收室41d、保持室41c、回收室41d之方式地配置。此 外，於容器本體41a之與玻璃帶6相對向的位置，設置有 開口部41e，藉由此開口部41e，使保持室41c及回收室 4 1 d開放。此外’於保持室4 1 c裝設有供應管6 1，並供應 有藉由帶電化裝置51予以帶電之疵點產生防止劑μ。 此外，於回收室4 1 d係裝設有氣體導出管4 1 h，藉此 ’可將從保持室41c回收至回收室41d之包含疵點產生防 止劑Μ之導入氣體，排出至徐冷爐3的外部。 亦即，回收室4 1 d係藉由間隔壁部4 1 b與帶電化室 [S3 -24- 1360526 41c區隔’此間隔壁部41b的上端部41bl，係位於較容器 本體41a的上端部41al更下側。藉此，於從保持室41c 所供應之疵點產生防止劑Μ的一部分未附著於玻璃帶6而 飛散至周圍時，可藉由容器本體41a的上端部41al將飛 馭的疵點產生防止劑Μ予以擋住，而成爲可回收奪回收笔_ 4 1 d之形式。 此外，於回收室41d，係裝設有用以吸引回收室41d 內的環境氣而取出之氣體導出管41h。藉此，可將回收至 回收室41d之疵點產生防止劑Μ，排出至保持容器41及 徐冷爐3的外部。藉由將上述構成的回收室41d設置於保 持室4 1 c的兩側，可防止疵點產生防止劑Μ飛散至徐冷爐 3的內部，而防止疵點產生防止劑Μ對徐冷爐3內造成污 染，此外並可再生利用取出至外部的疵點產生防止劑Μ。 由於保持容器41係設置在環境溫度爲700 °C左右之徐 冷爐3的入口附近，因此，構成保持容器41之容器本體 4 1 a及間隔壁部4 1 b等構件，較理想均以具有耐熱性之材 料所構成。此外，由於在保持容器41中收納有帶電的疵 點產生防止劑Μ，因此，容器本體41a、間隔壁部41b及 整流構件5 3 b等構件，較理想均以具有絕緣性之材料所構 成。滿足耐熱性及絕緣性之材料，例如有以石英玻璃或二 氧化鋁系陶瓷所代表之各種耐熱性陶瓷。 接著，供應管6 1爲用以將帶電的疵點產生防止劑Μ 供應至保持容器4 1之配管，一部分係配設於徐冷爐3的 外部，其餘部分則配設於徐冷爐內部。此外，於供應管6 1 iS] -25- 1360526 的內部，搬運有帶電的疵點產生防止劑Μ。因此，關於供 應管61，較理想以具有耐熱性之材料所構成。滿足耐熱性 及絕緣性之材料，例如有以石英玻璃或二氧化鋁系陶瓷所 代表之各種耐熱性陶瓷。 一此外，於ί共_里管6 1的中途丄較理想爲設置可圓滑地 輸送疵點產生防止劑且可予以重新帶電之感應電極61a。 如第7圖所示，感應電極61 a爲沿著供應管61之疵點產 生防止劑的流動方向而突出形成之棒狀電極。此感應電極 61a可連接於連接有帶電電極52之電源裝置，或是連接於 其他電源裝置。 接著說明於玻璃帶6形成緩衝層之方法。 首先，將疵點產生防止劑Μ供應至帶電化裝置51的 帶電·流動部5 1 c 1。之後，從氣體導入配管5 3 d例如將乾 燥空氣或氮氣等供應至氣體導入部51c2。亦可以不會對徐 冷爐3內部的溫度造成影響之方式，加熱乾燥空氣等之後 再導入。供應至氣體導入部51c2之乾燥空氣等，係通過 整流構件53b而從整流構件53b的上面全面一致地噴出至 帶電·流動部51cl。藉由此噴出後的乾燥空氣等，使由粉 體所構成之疵點產生防止劑飛舞，而使疵點產生防止劑Μ 成爲流動狀態。 此時’藉由將電力供應至帶電電極52，使疵點產生防 止劑Μ例如帶負電。帶電條件係因疵點產生防止劑μ的 種類、欲形成之緩衝層的厚度、及每單位時間的塗佈量而 有所改變，但較理想例如設定爲1 〇 kv以上、1 〇 〇 μ Α以上 I S1 -26- 1360526 帶電後的庇點產生防止劑Μ，係與乾燥空氣等一同送 出至供應管61。 送出至供應管61之疵點產生防止劑Μ，係隨著乾燥 空氣等巧流動而被輸送。此外，於通過感應電極61a的附 近時’可加速輸送速度並將一部分的疵點產生防止劑予以 重新帶電。亦可以不會對徐冷爐3內部的溫度造成影響之 方式，加熱乾燥空氣等之後再導入。 之後，經由供應管61供應至保持容器41的保持室 4 1 c之疵點產生防止劑Μ，係隨著乾燥空氣的流動，並藉 由拉出電極12朝玻璃帶6的下表面6a導引。此外，玻璃 帶6本身大致爲帶正電。因此，可使疵點產生防止劑μ 一 致地附著於玻璃帶6的下表面6a而形成緩衝層Β。此外 ，由於玻璃帶6本身爲帶正電，因此，雖然在不具備拉出 電極12時，亦可藉由乾燥空氣等的流動使帶負電的疵點 產生防止劑Μ形成緩衝層B，但具備拉出電極者，可更有 效率地形成緩衝層。 未帶電而未附著於玻璃帶6之疵點產生防止劑Μ，以 及雖然帶電但未附著於玻璃帶6之疵點產生防止劑Μ，係 藉由乾燥空氣等，經由保持室41c落下至回收室41d，並 經由氣體導出管41h與乾燥空氣等一同取出至帶電化保持 容器41的外部。藉此，可降低徐冷爐3內部的污染，並 且可將取出至外部之疵點產生防止劑Μ予以再利用。 藉由形成於玻璃帶6的下表面6a之緩衝層Β，即使 [S] -27- 1360526 層滾輪3b接觸於玻璃帶6的下表面6a’亦可因緩衝層的 存在而防止玻璃帶6之疵點的產生。此外’由於緩衝層B 本身僅藉由靜電效果而附著，因此容易藉由水洗等而予以 洗淨。因此，並不會產生緩衝層B對板玻璃的品質造成影 。― ________________ ______ ____________________________________ 如以上所說明般，根據本實施型態，與第1實施型態 相同，由於係藉由靜電塗裝法將由疵點產生防止劑Μ所構 成之緩衝層Β形成於玻璃帶6的下表面6a，因此，並無 疵點產生防止劑Μ於徐冷爐3內部飛散之疑慮，因此可防 止徐冷爐3內之設備的劣化。此外，由於係藉由所謂的靜 電塗裝法，使帶負電的疵點產生防止劑Μ附著於帶正電的 玻璃帶6而形成緩衝層Β，因此不會受到玻璃組成的限制 而能夠形成緩衝層Β，藉此，即使如液晶顯示用的板玻璃 般之無鹼玻璃，亦可形成緩衝層Β而防止疵點的產生。 此外，係使用由保持帶電的疵點產生防止劑Μ之保持 容器41;具有帶電電極52與帶電化保持容器53而成之帶 電化裝置5 1 ;及供應管6 1所構成之形成裝置3 1，因此， 可藉由帶電化裝置51，使疵點產生防止劑Μ成爲流動狀 態並有效率地予以帶電，並藉由將此供應至供應管6 1，可 提升緩衝層Β的形成效率並完整地於玻璃帶6的下表面 6a全面形成緩衝層Β。此外，由於帶電化裝置5 1設置於 徐冷爐3的外部，因此可容易進行疵點產生防止劑Μ的補 給並提高生產性。 再者，根據本實施型態，由於可藉由回收室41d及氣 m -28- 1360526 體導出管41h將未附著的疵點產生防止劑μ排出至徐冷爐 3的外部’因此，徐冷爐3的內部不會受到疵點產生防止 劑Μ的污染’此外’亦可將疵點產生防止劑μ予以再利 用。 ______本發明之技術性範圍並不限定於上述實施型態，可在 不脫離本發明的主旨之範圍內進行種種的變更。例如，於 上述各實施型態中，係藉由靜電塗裝法形成緩衝層，但本 發明並不限定於此，只要爲可使疵點產生防止劑Μ帶電且 朝玻璃帶6的下表面6a流動之方法均可，例如可使用靜 電噴霧法。此外’由於玻璃帶6本身爲帶正電，因此，即 使不具備拉出電極12，亦可藉由乾燥空氣等的流動將帶負 電的疵點產生防止劑Μ導引至玻璃帶側而能夠形成緩衝層 ’因此亦可省略拉出電極12。 實施例 以下係藉由實施例而更詳細說明本發明》 本實施例之評估方法，係使用：（i )疵點產生防止 劑之附著量的評估（每單位面積（1mm2)的附著量）；（ U)依據摩擦係數測定器之玻璃帶的常溫摩擦係數的變化 ：(iii )於實際的玻璃板之每單位面積的疵點產生數（個 )的變化之3個項目，作爲評估項目。（Π )係使用新 東科學株式會社（日本）製的TRIBOSTATION(TYPE32 )進行測定，而測定出在玻璃樣本的上方，以直徑8mm 的球型接觸件增加50g並進行摩擦時之摩擦係數。 i S1 -29- 1360526 「實驗1 j 將第1圖〜第5圖所示的構成之緩衝層形成裝置（第1 實施型態。以下稱爲裝置1)組裝於板玻璃之製造設備並 進行評估。疵點產生防止劑係使用平均粒徑ΙΟμπι (最大 ^ ~ ~ _ — - — - - - — — - - _ _ . 一 _ 粒徑50μηι )之硫酸鈉（粉碎品），玻璃帶使用鈉鈣玻璃 ’玻璃帶的搬運速度設定爲400m/小時。帶電化保持容器 的設置溫度爲55 0°C。此外，帶電條件（實施例1 )爲 3〇kV、10mA (針狀電極的數目：50根，每1根爲200μΑ )，帶電化保持容器的大小係設定爲長度5m，寬度20cm 。此外，帶電化保持容器的開口部與玻璃帶的下表面之間 的距離，係設定爲5 0mm。於此條件下，進行緩衝層的形 成。 其結果爲，疵點產生防止劑的附著量爲150個/ mm2 。此外，玻璃帶之常溫摩擦係數的變化，於未形成時爲 0.6 2 0，於形成緩衝層時爲0.1 6 8，摩擦係數係減少0.4 5 2 。再者，實際的玻璃板之每單位面積（個/m2)的疵點產 生數的變化，於未形成緩衝層時爲1〇〇〜200個/m2，相對 於此，於形成緩衝層時爲5個/m2。 從以上內容當中可得知，藉由形成緩衝層，可大幅減 少疵點的產生。 「實驗2」 將裝置1以及第7圖〜第8圖所示的構成之緩衝層形1360526 IX. Description of the Invention [Technical Fields of the Invention] The present invention relates to a method for manufacturing a sheet glass, a buffer layer forming device for a sheet glass, and a manufacturing apparatus for sheet glass, and more particularly to a board using a floating method.隽 隽 SAM 造 _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Pulling up from the outlet of the molten metal bath and pulling it out of the molten metal bath. The thickness of the target is formed by pulling the glass ribbon from the outlet of the bath. Next, the glass ribbon was conveyed on the removal roller and carried into the cold furnace, and the inside of the cold furnace was transported while being cold. The glass ribbon is then cut to a specific length to thereby produce a panel glass. In the above floating method, one side of the plate glass is formed by the bath surface of the molten metal, and the molten glass is spread on the molten metal to thereby form a free surface of the other side, and therefore, the flatness of the plate glass is extremely high, and It has also become a method suitable for mass production. Therefore, it is suitable for the production of glass for automobiles, glass for construction, glass for plasma display, and glass for liquid crystal display. In the floating method, in order to prevent cracking or flatness reduction due to rapid shrinkage of the glass, it is necessary to remove the high-temperature glass ribbon conveyed from the roller and to cool the glass while controlling the cooling rate in the subsequent cold furnace. Therefore, the length of the Xu cold furnace sometimes reaches the scale of hundreds of meters. In addition, -4-360362 'in the cold furnace, the glass ribbon is conveyed while being conveyed above the conveyance roller, etc., but the glass ribbon is in contact with the conveyance roller, etc., and there is a defect on the glass surface. Doubt. In order to prevent this defect, in the past, sulfur dioxide (so2) was introduced into the interior of the quench furnace, and the glass was reacted with S〇2 on the high-temperature glass surface to form, for example, sodium sulfate (Sodium Sulfate; Na2S04) or A buffer layer formed of sodium sulfite (Sodium Sulfite; Na2S03) or the like is used to suppress the occurrence of defects due to contact between the glass and the conveyance roller or the like by the buffer layer (see Patent Document 1). Patent Document 1: Japanese Laid-Open Patent Publication No. Hei No. Hei. No. 2-14841. SUMMARY OF THE INVENTION PROBLEMS TO BE SOLVED BY THE INVENTION However, since S02 is a highly corrosive gas, when S02 is introduced into a quench furnace, the inside of the quench furnace is caused. The equipment is corroded, and the durability of the quenching furnace is greatly reduced. Further, since the plate glass for liquid crystal display must have a circuit for forming a liquid crystal display element on the surface, an alkali-free glass containing almost no composition of an alkali metal which causes an adverse effect at the time of circuit formation is used. When the alkali-free glass is produced by the floating method, even if it is in contact with the 303 gas in the quenching furnace, since the alkali metal is hardly contained, it is difficult to form a buffer layer formed of sodium sulfate or sodium sulfite, and it is impossible to prevent the handling and handling. The problem of the occurrence of defects caused by the contact of the roller or the like. Furthermore, in order to carry out the production management of the glass plate, a missing detector is provided downstream of the glass manufacturing device [S3 - 5 - 1360526. Therefore, it is required to buffer the malfunction of the missing detector. Floor. The present invention has been made in view of the above circumstances, and an object of the invention is to provide a method for manufacturing a sheet glass which can suppress the occurrence of defects, and the sheet glass lining-punching-insulting device and the sheet glass filling s are prepared to replace the past. The means for forming the buffer layer of S〇2. (Means for Solving the Problem) In order to achieve the above object, the present invention adopts the following configuration. The method for producing a sheet glass according to the present invention comprises: forming a glass ribbon by continuously supplying molten glass to a horizontal bath surface of a molten metal bath containing molten metal; and transporting the glass ribbon to a cold furnace to be cold A method for producing a sheet glass of a cold-rolling process, characterized in that in the process after the forming process, the lower surface of the glass ribbon is charged to form a point-preventing agent to form a depression formed by a defect preventing agent. Floor. Further, in the method for producing a sheet glass of the present invention, the cushioning is preferably formed by an electrostatic coating method. Further, in the method for producing a sheet glass according to the present invention, it is preferable that a forming means for forming the buffer layer on a lower surface side of the glass ribbon is disposed in a process after the molding process; and the forming means is: a charged electrode on a lower surface side of the glass ribbon; and a charged holding container that houses the electrode with the electrode and holds the defect generating agent in a flowing state, and has an opening on the front glass ribbon side; The fuse is introduced into the front buffer layer and the surface is electrically charged. [S3 -6 - 1360526 The charged electrode is used to charge the antimony generating agent, and the antimony generating agent is prevented from the opening of the electrification holding container. The direction of the glass ribbon flows. Further, in the method for producing a sheet glass according to the present invention, it is preferable that a forming means for forming the buffer layer on a lower surface side of the glass ribbon is disposed in a process after the molding process; and the forming means is configured by: a holding container having an opening in a charged state and a flowing state on the lower surface side of the glass ribbon, and having an opening on the glass ribbon side; and a charging electrode and a charging electrode; a charging device for charging a holding container of a defect generating agent; and a supply tube for supplying the aforementioned defect generating preventing agent in a charged state to the holding container from the charging device; and generating the aforementioned defect by the charging electrode The prevention agent is charged, and the aforementioned defect generation preventing agent in a charged state is supplied to the holding container via the supply pipe, and the defect generation preventing agent flows from the opening of the holding container to the direction of the glass ribbon. Further, in the method for producing a sheet glass according to the present invention, it is preferable that a drawing electrode is disposed at a position facing the forming means via the glass ribbon; and the drawing of the electrode is performed by the drawing electrode The generation preventing agent is guided toward the lower surface of the glass ribbon, whereby the defect generation preventing agent adheres to the lower surface to form the buffer layer. Further, in the method for producing a sheet glass of the present invention, it is preferable that the antimony generating agent is an alkali metal or an alkaline earth metal chloride, an alkali metal or an alkaline earth metal chloride salt, an alkali metal or One or more powders selected from the group consisting of carbonates, oxide ceramics, nitride ceramics, and metal sulfides of the alkaline earth metal IS]-7- 1360526. * Next, the buffer layer forming device for sheet glass of the present invention is a buffer layer forming device for sheet glass provided in a manufacturing apparatus for a sheet glass. This sheet glass is provided with a molten metal. And in the aforementioned molten gold. a molten metal bath in which a horizontal bath surface is continuously supplied with molten glass to form a glass ribbon; and a cold-cold furnace for quenching the glass ribbon, characterized in that Φ: in the process after the molten metal bath, is in the glass The lower surface of the belt is charged to form a buffer layer formed of a defect generation preventing agent. . Next, the apparatus for manufacturing a sheet glass according to the present invention includes: a molten metal bath in which molten metal is accommodated, and molten glass is continuously supplied to a horizontal bath surface of the molten metal to form a glass ribbon; and the glass ribbon is subjected to The apparatus for manufacturing a sheet glass of a cold-cold furnace is characterized in that it is provided with a buffer layer forming device for sheet glass described above. EFFECTS OF THE INVENTION According to the present invention, it is possible to provide a panel which can suppress the generation of defects, a method for producing glass, a buffer layer forming device for sheet glass, and a sheet glass. The device is replaced by a conventional means for forming a buffer layer using so2. That is, according to the method for producing a sheet glass according to the present invention, a buffer layer formed of a defect preventing agent is formed on the lower surface of the glass ribbon in the process after the forming process, so that no defect generation preventing agent is diffused. As far as the inside of the cold furnace is concerned, even if the diffusion occurs, the gas in the corrosive-80-1360526 is not used, so that the deterioration of the equipment in the cold furnace can be prevented. Further, even if the lower surface of the glass ribbon is in contact with the transport roller or the like, the buffer layer formed on the lower surface of the glass ribbon can be used to prevent the occurrence of defects. In addition, in the method for manufacturing the sheet glass of the present invention, the coating is performed by electrostatic _ _ _ _ _ _ _ _ _ layer _ when the second - can not _! The glass layer is formed to form a buffer layer, and even if it is an alkali-free glass such as a plate glass for liquid crystal display, a buffer layer can be formed to prevent the occurrence of defects. Further, in order to perform production management of the glass sheet, a missing detector is installed downstream of the glass manufacturing apparatus, but since the buffer layer can be formed substantially uniformly on the lower surface of the glass ribbon, the missing detector can be prevented. Wrong action. The method of forming the buffer layer is not limited to the electrostatic coating method, and a method of forming a buffer layer on the lower surface of the glass ribbon by charging the defect generation preventing agent efficiently may be used. For example, an electrostatic spray method may be used. Further, in the method for producing a sheet glass of the present invention, a charging electrode disposed on a lower surface side of the glass ribbon is used, and a charging electrode is housed and a defect generating agent is maintained in a flowing state, and has a glass ribbon side In the case where the formation means for the electrification holding container of the opening portion is formed, the defect occurrence preventing agent is charged in the flow state, and the defect occurrence preventing agent is charged on the lower surface side of the glass ribbon. Therefore, the defect generation preventing agent can be efficiently generated. The charging is performed, and the charged defect generating agent is quickly attached to the glass ribbon to form a buffer layer, which improves the formation efficiency of the buffer layer and completely forms a buffer layer on the lower surface. Further, in the method for producing a sheet glass of the present invention, a holding container for generating an anti-cavitation agent by a defect in a charged state is used; a charging device having a charged electrode ί S3 -9-1360526 and a charged holding container: and a supply tube In the formation means, the deuterium generation preventing agent is brought into a flowing state and efficiently charged by the charging device, and is supplied to the supply pipe, whereby the formation efficiency of the buffer layer can be improved and the entire surface can be improved. Fully form the buffer layer. In addition, the electrification device is disposed outside the quenching furnace, and at this time, the deuterium generation preventing agent is charged to the outside of the quenching furnace, and the deuterium generation preventing agent in a charged state is supplied to the lower surface of the glass ribbon, so that the defect can be easily generated. Prevents replenishment and improves productivity. Further, in the method for producing a sheet glass according to the present invention, when the drawing electrode is disposed at a position facing the forming means via the glass ribbon, the electrode 2 is prevented from being charged toward the glass by the drawing electrode 1 2 The lower surface of the belt is guided, so that the buffer layer can be uniformly formed on the entire surface of the lower surface. Even if the lower surface of the glass ribbon contacts the transport roller of the quenching furnace, the buffer layer can be used to prevent the occurrence of defects. Further, in the method for producing a sheet glass according to the present invention, the antimony generating agent is an alkali metal or an alkaline earth metal chloride, an alkali metal or an alkaline earth metal chloride, an alkali metal or an alkaline earth. Since one or more types of powders selected from the group consisting of metal carbonates, oxide ceramics, nitride ceramics, and metal sulfides do not corrode equipment inside the furnace. According to the buffer layer forming apparatus for sheet glass of the present invention, in the process after the forming process, a buffer layer formed of a defect preventing agent is formed on the lower surface of the glass ribbon, so that no defect generating agent is generated. Dissipation to the inside of the cold furnace, and even if the diffusion occurs, the [S3 -10- 1360526 corrosive gas is not used, so the deterioration of equipment in the cold furnace can be prevented. Further, since the buffer layer can be formed without being affected by the composition of the glass, even if it is an alkali-free glass such as a plate glass for liquid crystal display, a buffer layer can be formed to prevent the occurrence of defects. Further, in order to perform production management of the glass sheet, a missing detector is attached downstream of the glass manufacturing apparatus, but the malfunction of the missing detector can also be prevented. Further, according to the apparatus for manufacturing a glass of the present invention, since the cushioning device is provided, it is possible to prevent not only deterioration of the equipment in the quenching furnace, but also to form a buffer layer without being affected by the glass composition, thereby preventing generation of defects. Further, in order to carry out the production management of the glass sheet, a missing detector is installed downstream of the glass manufacturing apparatus, but the malfunction of the missing detector can also be prevented. [Embodiment] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The drawings referred to in the following description are for explaining the configuration of the buffer layer forming apparatus of the plate glass of the present embodiment and the manufacturing apparatus of the sheet glass, and the size, thickness, and size of each part shown in the drawings. The dimensional relationship between the actual buffer layer forming device and the manufacturing equipment is different. "First embodiment" Hereinafter, a first embodiment of the present invention will be described. Fig. 1 is a schematic cross-sectional view showing a part of a manufacturing apparatus for a sheet glass of the present embodiment, and Fig. -11 - 1360526 2 is a perspective view showing a buffer layer forming apparatus provided in a manufacturing apparatus for a sheet glass, Fig. 3 A side view of a buffer layer forming apparatus provided in a manufacturing apparatus for a display panel glass, a fourth perspective view showing a special portion of the buffer layer forming apparatus, and a fifth drawing showing a special portion of the buffer layer forming apparatus face. Figure. The apparatus for manufacturing the sheet glass shown in Fig. 1 is provided in a subsequent stage of a melting and clearing tank (not shown in the drawings) for modulating the molten glass, and is substantially composed of a molten metal tank containing the molten metal la 1; a transfer chamber 2 installed in the rear stage of the molten metal tank 1; and a cold furnace 3 installed in the rear stage of the transfer chamber 2. In the vicinity of the inlet 3a of the cold furnace 3, the buffer layer forming device 4 of the present invention is provided. Further, in the latter stage of the cold furnace 3, a missing detector which is omitted in the drawing for inspecting the surface of the glass ribbon and a cutting machine which is omitted in the drawing after cooling are provided. The molten metal tank 1 is filled with a molten metal 1 a made of metal tin or the like, and the molten glass 5 is continuously supplied from the melting and clearing tank (not shown in the drawings, the same applies hereinafter) to the bath surface of the molten metal la 1B is constructed. The transfer chamber 2 has a removal roller 2a, and the glass ribbon 6 formed into a plate shape is pulled out from the molten metal tank 1 by the pulling force of the removal roller 2a. Further, the layered roller 3b is provided in the cold furnace 3, and the glass ribbon 6 conveyed from the transfer chamber 2 is conveyed by the layer roller 3b in the quenching furnace 3. The molten glass 5 melted in the melted clearing tank is continuously supplied from the melted clear tank to the bath surface 1B of the molten metal la of the molten metal tank 1 rsi -12 - 1360526 . After the molten glass 5 is formed into a desired thickness and width, it is pulled out from the outlet of the molten metal tank 1 by the pulling force of the removal roller 2a. At this time, the molten glass 5 is adjusted to a temperature at which plastic deformation is possible to become a glass/belt 6. The formed glass ribbon 6' passes through the transport chamber 2 and is transported to the cold furnace 3, and is slowly cooled as it passes through the interior of the quench oven 3. At this time ________ _- - - - - - - - - - - - - ~ ~ - . The buffer layer forming device 4 provided on the inlet 3a of the cold furnace 3 is used to form a buffer layer for preventing the occurrence of defects on the lower surface 6a of the glass ribbon 6. In the present embodiment, the buffer layer forming device is described. In the case of the inlet 3a of the cold furnace, it may be a process after the molten metal bath 1, and may be provided, for example, in the transfer chamber 2. In view of the prevention of flaws in the glass ribbon, it is preferable to be disposed as far as possible downstream of the molten metal bath 1, but it is preferably provided at the inlet of the quench furnace 3 which is relatively stable in the glass state (hereinafter, in the embodiment 2) The same is true). φ (buffer layer forming apparatus) Next, an example of the buffer layer forming apparatus 4 of the present invention will be described with reference to Figs. 2 to 5 . The buffer layer forming device 4 shown in Figs. 2 and 3 is disposed on the lower surface 6a side of the glass ribbon 6 and is in a charged state. The apparatus 1 1 (forming means) for forming a defect prevention agent which maintains a defect generation preventing agent in a flow state, and the drawing electrode 12 which is disposed at a position facing the forming device 11 via the glass ribbon 6 is formed. The forming device 11 (forming means) shown in Figs. 2 to 5 is attached to the lower surface 6a side of the glass ribbon 6, and the defect generating agent is charged. {S] -13 - 1360526 The drawing electrode 12 is formed in a plate shape of a substantially rectangular plate in plan view, and is disposed such that the longitudinal direction thereof coincides with the width direction Η of the glass ribbon 6. In addition, the length of the pull-out electrode 12 along the length direction is set to be the same as the width of the glass ribbon 6 or the width of the glass ribbon 6 is also the same as the width of the glass ribbon 6 - the inner - jm is connected by the __ wiring - 12 The high-voltage power supply unit not shown in the figure set on the outside of the 垮 琴 - - - is grounded. Further, the apparatus 11 for forming a defect prevention agent is a charged electrode 13 disposed on the lower surface 6a side of the glass ribbon 6, and a charged electrode 13 is housed, and the defect generation preventing agent μ is maintained in a flowing state, and is in the glass. The electrified holding container 4 having the opening portion 14e on the side of the belt 6 is constituted. As shown in FIG. 2, FIG. 3, and FIG. 5, the charging electrode 13 is composed of an electrode main body 13a extending in the width direction of the glass ribbon 6, and an upper side (glass ribbon 6 side) from the electrode main body 1 3 a. A plurality of protruding needle electrodes 1 3 b are formed. The needle electrodes 1 3 b are arranged at equal intervals with each other. The material of the charging electrode 13 is preferably formed of a heat-resistant material which does not deform at 700 ° C and is not oxidized. For example, a stainless steel alloy, nickel or a nickel alloy is preferable. Further, the mutual spacing of the needle electrodes 1 3 b can be set, for example, at a ratio of one width per 1 〇 cm of the width of the glass ribbon 6. The shape of the charging electrode 13 does not need to be in the shape of the embodiment, and the shape is not particularly limited as long as the defect generating agent Μ can be charged efficiently. A wiring 13c is connected to one end side of the electrode main body 13a, and the charging electrode 13 is connected to a high-voltage power supply device (not shown) provided on the outside of the quenching furnace 3 via the wiring 1 3 c. ^ -14 - 1360526 Next, as shown in Figs. 2 to 4, the electrification holding container 14 is composed of a container body 14a and a partition wall portion Mb which is vertically disposed in a pair of the inside of the container body 14a. The internal space of the container body 14a is divided into three spaces by a pair of partition walls 1 4 b. That is, the charging chamber 14C between the partition walls is formed in the container main body 14a, and the recovery chamber I4d disposed on both sides of the electrification chamber 14c is interposed between the partition walls 1b. The electrification chamber 14c and the recovery chamber Md are arranged such that the recovery chamber Md, the electrification chamber 14c, and the recovery chamber 14d are arranged in this order along the movement direction L of the glass ribbon 6. Further, an opening portion 14e is provided at a position facing the glass ribbon 6 of the container body Ma, and the charging electrode 13 is in the form of looking down the lower surface 6a of the glass ribbon 6. Further, the electrification chamber 14c is provided with a rectifying member 14f which is provided with pores which allow only gas to pass therethrough, and is located on the upper side of the rectifying member 14f, and is configured to be in a charged state and a flowing state. The charging/flowing portion 14cl that maintains the defect generation preventing agent 位于 is located on the lower side of the rectifying member I4f, and is configured to cause the gas to be ejected toward the charging/flowing portion 1 4 c 1 in order to cause the defect generating agent Μ to be in a flowing state. The introduction unit 1 4 c 2 . In the charging/flowing portion 14cl, the charging electrode 13 is disposed above the rectifying member 14f. Further, a gas introduction pipe 14 g is attached to the gas introduction portion 14c2. Further, a supply device (not shown in the drawings) for supplying the defect generation preventing agent 装 is attached to the charging/flowing portion 14c 1 . The supply device is, for example, a screw conveyor. The anti-cavitation agent Μ is supplied to the charging/flowing portion 1 4c 1 , and it is preferable to be attached to the glass ribbon 6 to generate a buffering effect, and it is easy to form a flowing state at a high temperature [S] -15 - 1360526, which is easy to be charged and does not occur. Condensed into coarse particles, does not cause chemical reaction with the glass and is easy to wash away, and does not corrode the equipment inside the quenching furnace 3, and is preferably, for example, from alkali metal or alkaline earth metal sulfate, metal examination or soil testing. Metal-like chloride salts, alkali metals or soil-based gold! One or more powders selected from the group consisting of carbonates, oxide ceramics, nitrogen oxide ceramics, and metal sulfides, more preferably Glauber's salt (sodium sulfate decahydrate) or sodium carbonate Powder. The average particle diameter of the antimony agent is preferably 20 μm or less, and the particle size is not particularly limited as long as the antimony generating agent is allowed to adhere to the glass ribbon 6. In addition, the charging portion is provided by the opening portion 14e provided in the container body 14a. The flow portion 14c 1 and the recovery chamber 14d are open on the lower surface 6a side of the glass ribbon 6. In addition, each of the collection chambers 1 has a gas outlet pipe 14h, and is configured to discharge the introduction gas containing the defect generation agent 喷 which is discharged from the charging/flowing portion 14c1 and collected in the recovery chamber 14d, and discharge it to the container body 1 4 a. The outside. Since the electrification holding container 14 is disposed near the inlet of the quenching furnace 3 having an ambient temperature of about 700 °C, it is preferable that the container main body 14a, the partition wall portion 14b, and the rectifying member 14f which constitute the electrification holding container 14 are ideally formed. It is made of a material with heat resistance. Further, since the charging electrode 13 connected to the high-voltage power source device is housed in the electrification holding container 14, the members such as the container body 14a, the partition wall portion 14b, and the rectifying member 14f are preferably insulated. Made up of materials. The material satisfying the heat resistance and the insulating property is, for example, various heat-resistant ceramics represented by quartz glass or alumina-based 1360526 ceramics. The charging electrode 13 and the wiring 13c for the charging electrode are preferably insulated from the member of the electrification holding container 14 or the device inside the quenching furnace 3. When the charged electrode 13 and its wiring 13c are not sufficiently insulated, it will be discharged at a place where it is not turned off, and the environment in which the electrification is provided is a high temperature environment of several hundred ° C. Even if it is only a little insulation, it is easy to cause discharge. Regarding the insulation countermeasure, it is preferable that the metal member is not brought close to the wiring 13c inside the quenching furnace 3 as much as possible. Further, the wiring 13c is preferably covered with a heat-resistant and insulating material. Further, in order to prevent discharge from the contact portion of the wiring 1 3 c and the charging electrode 13 as shown in Fig. 1, Fig. 4 or Fig. 5, it is preferable that the side wall portion of the electrification holding container 14 is provided with insulation. A tube 14i composed of a material is inserted into the tube 14i of the charging electrode, and is connected in the container body 14a, and partially satisfies heat resistance and insulation so as not to cause discharge. The material is covered. The material of the tube 14i is the same as the constituent material of the electrification holding container 14, and a material that satisfies heat resistance and insulation can be used. Next, the recovery chamber 14d will be described in detail. The recovery chamber 14d is separated from the electrification chamber 14c by the partition wall portion 14b. The upper end portion 14b1 of the partition wall portion 14b is located lower than the upper end portion 14a1 of the container body 14a. Thereby, when a part of the defect preventing agent 从 which is supplied from the electrification chamber 1 4 c is not adhered to the glass ribbon 6 and is scattered to the surroundings, the scattered defect can be prevented by the upper end portion 14a 1 of the container body 14a. The agent is blocked and becomes recyclable to the recovery chamber 14d. Further, a gas outlet pipe 14h for taking out the ambient gas in the recovery chamber I4d [Si! -17-1360526) is attached to the recovery chamber 14d. Thereby, the preventive agent 回收 which is recovered in the recovery chamber 14d can be discharged to the outside of the electrification holding container 14 and the quenching furnace 3. By providing the recovery chamber 14d having the above-described configuration on both sides of the electrification chamber 14c, it is possible to prevent the defect occurrence preventing agent from scattering to the inside of the t-cooling furnace 3, and to prevent contamination of the inside of the quenching furnace 3 by the defect prevention agent. Further, it is possible to regenerate the defect generation agent 取出 which is taken out to the outside. If the distance between the opening portion 14e of the electrification holding container 14 and the glass ribbon 6 is too close, the glass ribbon 6 may be in contact with the electrification holding container 14 when the glass ribbon 6 is deflected, and further, If the distance between the opening portion 14e and the glass ribbon 6 is too far, there is a concern that the defect generation preventing agent 飞 may be scattered between the opening portion 14e and the glass ribbon 6, and the interior of the quenching furnace 3 is contaminated. Therefore, the electrification holding container 14 can be disposed close to the glass ribbon 6 to such an extent that it does not contact the glass ribbon 6, for example, the distance between the opening portion 1 4 e of the electrification holding container 14 and the glass ribbon 6 can be set. It is 2~5 cm. Next, a method of forming a buffer layer on the glass ribbon 6 will be described with reference to Fig. 6. First, the defect generation preventing agent Μ is supplied to the charging/flowing portion 1 4c 1 of the electrification holding container 14. After that, the gas introduction pipe 14 g is supplied to the gas introduction portion 14c2 by, for example, dry air or nitrogen gas (hereinafter also referred to as dry air). It is also possible to introduce the method of heating the dry air or the like without affecting the temperature inside the cold furnace 3. The dry air or the like supplied to the gas introduction portion 14c2 is uniformly discharged from the upper surface of the rectifying [S] -18-1360526 member 14f to the charging/flowing portion Mcl by the rectifying member 14f. By the dry air or the like after the discharge, the defect generation preventing agent composed of the powder is caused to fly, and the defect generation preventing agent becomes a flowing state. At this time, the electric power is supplied to the charging electrode 13 to cause the defect to be generated. Prevent ^^^ Example _If negatively charged. The charging condition is changed depending on the type of the anti-cavitation agent Μ, the thickness of the buffer layer to be formed, and the coating amount per unit time. However, it is preferable to set the defect to 10 kV or more and ΙΟΟμΑ or more. The prevention agent enthalpy is guided by the needle electrode 13b toward the lower surface 6a of the glass ribbon 6. Further, the charged defect causes the preventive agent Μ, and can also be guided toward the lower surface 6a of the glass ribbon 6 by the drawing electrode 12. Furthermore, the glass ribbon 6 itself is substantially positively charged. By the above manner, the defect generation preventing agent can be adhered to the lower surface 6a of the glass ribbon 6, as shown in Fig. 6, and the buffer layer B is formed on the lower surface 6a of the glass ribbon 6. After being in a flowing state in the charging/flowing portion 14c1 by dry air or the like, the anti-charge agent does not adhere to the glass ribbon 6, and the anti-cavitation agent is generated, and the crucible which is not attached to the glass ribbon 6 is generated. The agent sputum is dropped to the recovery chamber i4d, and taken out to the outside of the electrification holding container 14 together with the dry air or the like via the gas discharge pipe 14h. Thereby, the contamination inside the quenching furnace 3 can be reduced. Further, the defect is taken out to the outside to generate a preventive agent, which can be collected by a filter and reused. By the buffer layer 形成 formed on the lower surface 6a of the glass ribbon 6, even if the layer roller 3b for transporting the glass ribbon 6 contacts the lower surface -19-1360526 6a of the glass ribbon 6, it may be due to the presence of the buffer layer B. Prevent the occurrence of defects in the glass ribbon 6. Further, since the buffer layer B itself is adhered only by the electrostatic effect, it is easily washed by water washing or the like. Therefore, there is no doubt that the buffer layer B affects the quality of the sheet glass. As described above, according to the present embodiment, since the buffer layer B composed of the defect prevention agent Μ is formed on the lower surface 6a of the glass ribbon 6 by the electrostatic coating method, there is no defect prevention agent. The suspicion of scattering inside the cold furnace 3 prevents the deterioration of the equipment in the cold furnace 3. Further, since the negatively charged defect generation preventing agent Μ adheres to the positively charged glass ribbon 6 to form the buffer layer by the so-called electrostatic coating method, the buffer layer can be formed without being restricted by the glass composition. Β In this way, even if the alkali-free glass is used like a plate glass for liquid crystal display, a buffer layer can be formed to prevent the occurrence of defects. Further, the electrification holding container 14 is disposed on the lower surface 6a side of the glass ribbon 6, and the drawing electrode 12 is disposed at a position opposed to the electrification holding container 14, and is brought into a charged state by pulling out the electrode 12. The defect generation preventing agent 导引 is guided toward the lower surface 6a of the glass ribbon 6, and the defect generation preventing agent Μ is attached to the lower surface 6a to form the buffer layer B, so that the buffer layer B can be formed on the lower surface 6a. In all aspects, even if the lower surface 6a of the glass ribbon 6 is in contact with the layer roller 3b of the quenching furnace 3, the generation of the flaw of the glass ribbon 6 can be prevented by the buffer layer B which is uniformly formed on the lower surface 6a. In addition, since the glass ribbon 6 itself is positively charged, the negatively-charged defect generation preventing agent Μ can be guided to the glass ribbon side by the flow of dry air or the like when the extraction electrode 12 is not provided. Shape S S] -20- 1360526 becomes the buffer layer B, but with the pull-out electrode 12, the buffer layer B can be formed more efficiently. Further, since the defect generation preventing agent is charged on the lower surface 6a side of the glass ribbon 6, the charged defect generating agent μ can be quickly adhered to the glass ribbon 6 to form a buffer layer, and the buffer layer can be lifted. The formation efficiency and complete formation of the buffer layer 完整 on the lower surface 6a. Further, according to the present embodiment, since the unattached defect generation preventing agent Μ can be discharged to the outside of the quenching furnace 3 by the recovery chamber 14d and the gas discharge pipe 14h, the inside of the quenching furnace 3 is not subjected to the defect generation preventing agent. In addition, the antimony generating agent μ can be reused. "Second embodiment" Next, a buffer layer forming device 24 of the second embodiment will be described with reference to Figs. 7 and 8. Among the components shown in Figs. 7 and 8 , the same components as those described in Figs. 1 to 6 are denoted by the same reference numerals, and the description is omitted or simplified. The buffer layer forming device 24 shown in Fig. 7 is a forming device 3 1 (forming means) for holding the defect preventing agent 带 in a charged state on the lower surface 6a side of the glass ribbon 6; The glass ribbon 6 is disposed between the drawing electrodes 12 at positions facing the forming device 31. The forming device 31 (forming means) shown in Fig. 7 is for charging the defect generating agent Μ, and forms a burnt-in preventing agent in the charged state on the lower surface 6a side of the glass ribbon 6. [S3 - 21 - 1360526 The electrode 12 is pulled out, and is formed into a plate-like electrode having a substantially rectangular shape in plan view, similarly to the pull-out electrode of the first embodiment, and is connected to the outside of the quenching furnace 3 via the wiring 12a. A high voltage power supply unit not shown in the setup diagram, or grounded. In addition, the apparatus 31 for forming the defect preventing agent 大致 is substantially a holding container 41 which is disposed on the lower surface 6a side of the glass ribbon 6 and which is in a charged state, and is charged to the outside of the quenching furnace 3 The device 51; and the supply of the defect generation preventing agent 带 in the charged state from the charging device 51 to the supply pipe 61 of the holding container 41. In the present embodiment, the forming device 3 1 in which the electrification device 51 is disposed outside the quenching furnace 3 will be described, but the installation place is not particularly limited. When the electrification device 51 is installed outside the quenching furnace, the antimony generating agent Μ is charged outside the quenching furnace, and the deuterium generation preventing agent 带 in the charged state is supplied to the lower surface side of the glass ribbon 6, so that it is easy. It is preferable to carry out the replenishment of the antimony generating agent and improve the productivity. As shown in Figs. 7 and 8, the electrification device 51 is composed of a hollow container body 53a and a rectifying member 53b disposed inside the container body 53a. The rectifying member 533b is a member provided with pores to which only gas can pass. Further, the internal space of the container body 533a is divided into two spaces by the flow regulating member 533b. That is, in the container body 5 3 a, the charging/flowing portion 5 1 c 1 on the upstream side of the rectifying member 533b and the gas introducing portion 5 1 on the downstream side of the rectifying member 533b are formed. c 2. In the charging/flowing portion 5 1 c 1 , the gas introduction portion 51 c 2 ′ is held in a charged state and a flowing state, and the gas introduction portion 51 c 2 ′ is caused to cause the target generation preventing agent 流动 to flow. The gas is ejected toward the charging/flowing unit 5 k 1 . A gas introduction pipe 53d is attached to the gas introduction portion 51c2. Further, in the charging/flowing portion 51cl, the charging electrode 52 is provided above the rectifying member 53b, and the supply pipe 61 for supplying the deuterium generation preventing agent 带 in the charged state to the holding container 41 is connected. As shown in FIGS. 7 and 8, the charging electrode 52 is composed of an electrode body 52a extending almost in the horizontal direction, and a needle electrode 52b vertically extending from the electrode body 52a in the vertical direction. Linear shaped wire electrode. In Figs. 7 and 8, the front end portion of the needle electrode 52b is inserted into the inside of the supply tube 61. With this configuration, the defect generation preventing agent can be efficiently charged. Further, it is not necessary to necessarily charge the needle electrode 52 to prevent the charge from being generated. Therefore, the present invention is not limited to the configuration and shape. Further, since the material ' of the charging electrode 52 is provided outside the quenching furnace 3, it is not particularly limited in heat resistance, and is not particularly limited as long as it has a good charging efficiency. A wiring 52c is connected to one end side of the electrode main body 52a, and the charging electrode 52 is connected to a high-voltage power supply device (not shown) via the wiring 52c. Further, the charging/flowing portion 5 1 c 1 is mounted. A supply device for preventing the occurrence of defects (not shown in the drawings). The supply device has, for example, a screw conveyor. The anti-cavitation agent Μ is supplied to the charging/flowing portion 5 1 c 1 , which is the same as the first embodiment of S 3 -23- 1360526, and is preferably, for example, a sulfate or an alkali metal or an alkali metal or alkaline earth metal. More preferably, one or more powders selected from the group consisting of chloride salts of alkaline earth metals, carbonates of alkali metals or alumina metals, oxide ceramics, nitride ceramics, and metal sulfides are preferred. Year J Xiao (sodium sulfate decahydrate) or sodium carbonate powder.疵点产 — ' - - - - - - - . The average particle diameter of the anti-promoting agent , is preferably, for example, 20 μm or less, and the particle size is not particularly limited as long as the anti-cavitation preventing agent is allowed to adhere to the glass ribbon 6. Next, as shown in Fig. 7, the holding container 41 is composed of a container body 41a and a partition wall portion 4 1 b which is vertically disposed in a pair of the inside of the container body 4 1 a. The internal space of the container body 41a is divided into three spaces by a pair of partition walls 41b. In other words, the container body 41a is formed with a holding chamber 4 1 c located between the partition walls and a recovery chamber 41d disposed on both sides of the holding chamber 41c. The holding chamber 41c and the recovery chamber 41d are arranged such that the recovery chamber 41d, the holding chamber 41c, and the recovery chamber 41d are arranged in this order along the moving direction L of the glass ribbon 6. Further, an opening 41e is provided at a position facing the glass ribbon 6 of the container body 41a, and the holding chamber 41c and the recovery chamber 4 1d are opened by the opening 41e. Further, a supply pipe 161 is mounted in the holding chamber 4 1 c, and a defect generation preventing agent μ which is charged by the charging device 51 is supplied. Further, a gas outlet pipe 4 1 h is installed in the recovery chamber 4 1 d, whereby the introduction gas containing the defect generation agent 回收 from the holding chamber 41c to the recovery chamber 41d can be discharged to the outside of the quench furnace 3 . That is, the recovery chamber 4 1 d is located at the upper end portion 41a of the container body 41a by the partition wall portion 4 1 b and the electrification chamber [S3 - 24 - 1360526 41c partitioning the upper end portion 41 b1 of the partition wall portion 41 b. Lower side. Thereby, when a part of the anti-cavitation agent which is supplied from the holding chamber 41c is not adhered to the glass ribbon 6 and is scattered to the surroundings, the anti-defective agent of the cornice can be prevented by the upper end portion 41a1 of the container main body 41a. Blocked, and become a form of recyclable _ 4 1 d. Further, a gas outlet pipe 41h for taking out the ambient gas in the recovery chamber 41d and taking it out is provided in the recovery chamber 41d. Thereby, the preventive agent 回收 which is recovered in the recovery chamber 41d can be discharged to the outside of the holding container 41 and the quenching furnace 3. By providing the recovery chambers 41d having the above-described configuration on both sides of the holding chambers 4 1 c, it is possible to prevent the defect occurrence preventing agent from scattering to the inside of the quenching furnace 3, and to prevent the occurrence of the defect generating agent Μ from contaminating the inside of the quenching furnace 3, and Recycling can be carried out by removing the defects generated to the outside. Since the holding container 41 is provided in the vicinity of the inlet of the quenching furnace 3 having an ambient temperature of about 700 ° C, the container main body 4 1 a and the partition wall portion 4 1 b constituting the holding container 41 are preferably heat-resistant. Made up of materials. Further, since the charging target generation preventing agent 收纳 is accommodated in the holding container 41, members such as the container main body 41a, the partition wall portion 41b, and the rectifying member 533b are preferably made of an insulating material. Materials which satisfy heat resistance and insulation properties include, for example, various heat resistant ceramics represented by quartz glass or alumina ceramics. Next, the supply pipe 61 is a pipe for supplying the charged defect generation preventing agent 至 to the holding container 41, and a part is disposed outside the quenching furnace 3, and the rest is disposed inside the quenching furnace. Further, inside the supply pipe 6 1 iS] -25 - 1360526, a charged defect generating agent 搬运 is carried. Therefore, it is preferable that the supply pipe 61 is made of a material having heat resistance. Materials which satisfy heat resistance and insulation properties include, for example, various heat-resistant ceramics represented by quartz glass or alumina-based ceramics. In addition, it is preferable to provide the induction electrode 61a which can smoothly convey the defect generation preventing agent and can be recharged in the middle of the ___ tube 6 1 . As shown in Fig. 7, the induction electrode 61a is a rod-shaped electrode which is formed to protrude in the flow direction of the prevention agent along the supply line 61. The sensing electrode 61a can be connected to a power supply unit to which the charging electrode 52 is connected, or to another power supply unit. Next, a method of forming a buffer layer on the glass ribbon 6 will be described. First, the defect generation preventing agent Μ is supplied to the charging/flowing portion 5 1 c 1 of the charging device 51. Thereafter, dry gas, nitrogen gas or the like is supplied to the gas introduction portion 51c2 from the gas introduction pipe 5 3 d, for example. It is also possible to heat the dry air or the like without inhaling the temperature inside the cold furnace 3, and then introduce it. The dry air or the like supplied to the gas introduction portion 51c2 is uniformly discharged from the upper surface of the flow regulating member 53b to the charging/flowing portion 51cl by the flow regulating member 53b. By the dry air or the like which is ejected therefrom, the defect generating agent composed of the powder is caused to fly, and the defect generation preventing agent Μ is made to flow. At this time, by supplying electric power to the charging electrode 52, the defect generation agent Μ is negatively charged, for example. The charging condition is changed depending on the type of the anti-suppressing agent μ, the thickness of the buffer layer to be formed, and the coating amount per unit time, but it is preferably set to, for example, 1 〇kv or more and 1 〇〇μ Α or more. I S1 -26- 1360526 The seat generation prevention agent 带 after being charged is sent to the supply pipe 61 together with dry air or the like. The defect generation agent 送 which is sent out to the supply pipe 61 is conveyed as the dry air or the like flows. Further, at the vicinity of the sensing electrode 61a, the conveying speed can be accelerated and a part of the defect generating preventing agent can be recharged. It is also possible to introduce dry air or the like without affecting the temperature inside the cold furnace 3. Thereafter, the prevention agent Μ is supplied to the holding chamber 4 1 c of the holding container 41 via the supply pipe 61, and is guided by the drawing electrode 12 toward the lower surface 6a of the glass ribbon 6 by the flow of the dry air. In addition, the glass ribbon 6 itself is substantially positively charged. Therefore, the defect generation preventing agent μ can be uniformly adhered to the lower surface 6a of the glass ribbon 6 to form the buffer layer Β. In addition, since the glass ribbon 6 itself is positively charged, the buffer layer B may be formed by a negatively charged defect generating agent to form the buffer layer B by the flow of dry air or the like when the electrode 12 is not provided. The electrode can be formed more efficiently by the electrode. The anti-cavitation agent Μ which is not charged but not adhered to the glass ribbon 6 and the anti-cavitation agent Μ which is not attached to the glass ribbon 6 after being charged are dropped into the recovery chamber 41d via the holding chamber 41c by dry air or the like. The gas is taken out to the outside of the electrification holding container 41 together with the dry air or the like via the gas outlet pipe 41h. Thereby, the contamination inside the quenching furnace 3 can be reduced, and the antimony generating agent which is taken out to the outside can be reused. By the buffer layer 形成 formed on the lower surface 6a of the glass ribbon 6, even if the [S] -27-1360526 layer roller 3b contacts the lower surface 6a' of the glass ribbon 6, the glass ribbon 6 can be prevented by the presence of the buffer layer. The production of defects. Further, since the buffer layer B itself adheres only by the electrostatic effect, it is easily washed by water washing or the like. Therefore, the buffer layer B is not caused to affect the quality of the plate glass. ― ________________ ______ ____________________________________ As described above, according to the present embodiment, as in the first embodiment, the buffer layer 构成 composed of the defect preventing agent Μ is formed on the glass ribbon 6 by electrostatic coating. Since the lower surface 6a does not have any fear that the anti-cavitation agent is scattered inside the quenching furnace 3, deterioration of the equipment in the quenching furnace 3 can be prevented. Further, since the negatively charged defect generation preventing agent Μ adheres to the positively charged glass ribbon 6 to form the buffer layer by the so-called electrostatic coating method, the buffer layer can be formed without being restricted by the glass composition. Therefore, even if the alkali-free glass is used like a plate glass for liquid crystal display, a buffer layer can be formed to prevent the occurrence of defects. Further, a holding container 41 for generating a preventive agent 保持 by holding a charged defect; a charging device 51 having a charging electrode 52 and a charging holding container 53; and a forming device 3 1 composed of a supply tube 61 are used. Therefore, the antimony generating agent Μ can be made into a flowing state and charged efficiently by the charging device 51, and by supplying this to the supply pipe 61, the formation efficiency of the buffer layer can be improved and intact. The lower surface 6a of the glass ribbon 6 integrally forms a buffer layer. Further, since the electrification device 51 is disposed outside the quenching furnace 3, it is possible to easily supply the antimony generating agent Μ and improve productivity. Further, according to the present embodiment, since the unattached defect generation preventing agent μ can be discharged to the outside of the quenching furnace 3 by the recovery chamber 41d and the gas m-28-136026 body discharge pipe 41h, the inside of the cold furnace 3 is not It is also contaminated by the antimony generating agent 此外, and the antimony generating agent μ can be reused. The technical scope of the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit and scope of the invention. For example, in each of the above embodiments, the buffer layer is formed by an electrostatic coating method, but the present invention is not limited thereto, as long as the defect generating agent 疵 is charged and flows toward the lower surface 6a of the glass ribbon 6. Any method can be used, for example, an electrostatic spray method can be used. Further, since the glass ribbon 6 itself is positively charged, even if the drawing electrode 12 is not provided, the negatively charged defect generating agent Μ can be guided to the glass ribbon side by the flow of dry air or the like to form a buffer. The layer 'so the electrode 12 can also be omitted. EXAMPLES Hereinafter, the present invention will be described in more detail by way of examples. The evaluation method of the present embodiment uses: (i) evaluation of the adhesion amount of the antimony generating agent (adhesion amount per unit area (1 mm 2 )); U) Change in the coefficient of friction of the room temperature of the glass ribbon according to the friction coefficient measuring device: (iii) 3 items of the change in the number of defects per unit area of the actual glass plate as an evaluation item. (Π) The measurement was carried out by using TRIBOSTATION (TYPE 32) manufactured by Shinto Scientific Co., Ltd. (Japan), and the coefficient of friction when the spherical contact of 8 mm in diameter was increased by 50 g and friction was measured above the glass sample. i S1 -29- 1360526 "Experiment 1 j The buffer layer forming apparatus (the first embodiment, hereinafter referred to as the device 1) having the configuration shown in Figs. 1 to 5 is assembled to the manufacturing equipment of the sheet glass and evaluated. The anti-defective generation agent uses an average particle size ΙΟμπι (maximum ^ ~ ~ _ - - - - - - - - - - _ _ . A sodium sulfate (pulverized product) having a particle diameter of 50 μm) and a soda lime glass in the glass ribbon were used. The conveying speed of the glass ribbon was set to 400 m/hr. The set temperature of the electrified holding vessel is 55 °C. Further, the charging conditions (Example 1) were 3 〇 kV, 10 mA (the number of needle electrodes: 50, 200 μ Å per one), and the size of the electrification holding container was set to a length of 5 m and a width of 20 cm. Further, the distance between the opening of the electrification holding container and the lower surface of the glass ribbon was set to 50 mm. Under these conditions, the formation of a buffer layer is performed. As a result, the amount of adhesion preventing agent adhesion was 150 / mm 2 . In addition, the change in the coefficient of friction of the glass ribbon at room temperature is 0 when it is not formed. 6 2 0, 0 when forming the buffer layer. 1 6 8, the coefficient of friction is reduced by 0. 4 5 2 . In addition, the number of defects per unit area (number/m2) of the actual glass plate varies from 1 to 200/m2 when the buffer layer is not formed, and is 5 when the buffer layer is formed. /m2. As can be seen from the above, by forming the buffer layer, the occurrence of defects can be greatly reduced. "Experiment 2" The buffer layer of the device 1 and the structures shown in Figs. 7 to 8
-30- 1360526 成裝置（第2實施型態。以下稱爲裝置2)，分別組裝於 板玻璃之製造設備並進行評估。於實驗2中，係將帶電條 件改變爲如第1表（實施例2〜9 )所示之內容，除此之外 的實驗條件，係與實驗1相同而進行緩衝層的形成。 「實驗3」 爲了與先前技術進行比較，係將so2導入至玻璃製造 設備的徐冷爐內部，使玻璃與S〇2反應而形成由硫酸鈉所 構成之緩衝層（比較例1 )。 「評估」 對於實驗2及實驗3中所形成之緩衝層’係進行與實 驗1相同之評估項目的測定，並於第1表中顯示該結果。 對於未進行任何緩衝層的形成之玻璃樣本’亦進行同樣的 測定，並作爲比較例2而顯示於第1表中°-30- 1360526 The apparatus (the second embodiment, hereinafter referred to as the apparatus 2) was assembled and evaluated in the manufacturing equipment of the sheet glass. In Experiment 2, the charging conditions were changed to those shown in Table 1 (Examples 2 to 9), and the other experimental conditions were the same as in Experiment 1 to form a buffer layer. "Experiment 3" In order to compare with the prior art, so2 was introduced into a quench furnace of a glass manufacturing facility, and glass was reacted with S?2 to form a buffer layer composed of sodium sulfate (Comparative Example 1). "Evaluation" The evaluation of the same evaluation items as in Experiment 1 was carried out for the buffer layers formed in Experiments 2 and 3, and the results are shown in Table 1. The same measurement was carried out for the glass sample ' without any buffer layer formation, and is shown in the first table as Comparative Example 2.
[S3 -31 - 1360526 [第1表] 裝置種類 纖觀 電壓 (kV) 電流 (mA) 附著量 (個/mm2) 摩擦 係數 疵點頻率 (個/m2) 實施例1 裝置1 Na2S〇4 30 10 150 0.168 約5 實施例2 裝置1 Na2S〇4 50 10 160 0.168 約5 實施例3 裝置1 Na2S〇4 10 10 120 0.204 約5 …實施例4 裝置1 Na2S〇4 30 1 10 0.484 20-30 實施例5 裝置1 Na2S〇4 30 5 80 0.332 10-20 實施例6 裝置1 Na2S〇4 30 20 250 0.108 1~2 實施例7 裝置2 Na2S04 30 10 60 0.360 10-20 實施例8 裝置2 N&2S〇4 30 5 20 0.420 20-30 實施例9 裝置2 N3.2SO4 30 20 120 0.200 約5 比較例1 以往裝置 (硫酸鹽） — — — — 0.404 30 比較例2 均無 — — — — 0.620 100-200[S3 -31 - 1360526 [Table 1] Device type Mesoscopic voltage (kV) Current (mA) Attachment amount (pieces/mm2) Friction coefficient defect frequency (units/m2) Example 1 Device 1 Na2S〇4 30 10 150 0.168 About 5 Example 2 Apparatus 1 Na2S〇4 50 10 160 0.168 About 5 Example 3 Apparatus 1 Na2S〇4 10 10 120 0.204 About 5 Example 4 Apparatus 1 Na2S〇4 30 1 10 0.484 20-30 Example 5 Apparatus 1 Na2S〇4 30 5 80 0.332 10-20 Example 6 Apparatus 1 Na2S〇4 30 20 250 0.108 1~2 Example 7 Apparatus 2 Na2S04 30 10 60 0.360 10-20 Example 8 Apparatus 2 N& 2S〇4 30 5 20 0.420 20-30 Example 9 Device 2 N3.2SO4 30 20 120 0.200 Approx 5 Comparative Example 1 Conventional device (sulphate) — — — — 0.404 30 Comparative Example 2 None — — — — 0.620 100-200
如第1表所示，實施例1〜9係表示出較以往例之比較 例1爲同等程度或更少之疵點產生頻率，可得知具有良好 的疵點產生防止效果。 此外，關於實施例1〜9，可確認其摩擦係數及疵點產 生頻率與粒子的附著量呈反比而減少，尤其附著量與電流 量具有較高的相關性。 此外，於此次的緩衝層形成時，並未引起徐冷爐的後 段所設置之缺失檢測器的錯誤動作，且可藉由洗淨而簡單 地去除附著的緩衝層，此外，亦未確認到徐冷爐內的污染 因此，藉由本發明，可在不使用以往的S 02的情況下 形成緩衝層，所以並不會腐蝕設備且不會使設備下游之缺 I S1 -32- 1360526 失檢測器產生錯誤動作，而能夠抑制疵點的產生。此外， 於本發明中，並未特別選擇玻璃的組成，因此，可於無鹼 玻璃之液晶顯示用的板玻璃上形成緩衝層，而抑制疵點的 產生。再者，亦不會引起徐冷爐的後段所設置之缺失檢測 器的錯誤動作。 產業上之可利用性： 本發明可適用於使用浮式法之板玻璃之製造方法，尤 其適用於使用浮式法之高品質的板玻璃之製造方法。 在此，係引用於2007年4月3日所申請之日本特許 出願2007-097203號的說明書、申請專利範圍、圖式及發 明摘要的全部內容，作爲本發明的說明書予以揭示。 【圖式簡單說明】 第1圖係顯示本發明的第1實施型態之板玻璃之製造 設備的一部分之剖面模式圖。 第2圖係顯示本發明的第丨實施型態之板玻璃之製造 設備中所具備之緩衝層形成裝置之立體圖。 第3圖係顯示本發明的第1實施型態之板玻璃之製造 設備中所具備之緩衝層形成裝置之側視圖。 第4圖係顯示本發明的第1實施型態之緩衝層形成裝 置的特取部分之立體圖。 第5圖係顯示本發明的第1實施型態之緩衝層形成裝 置的特取部分之正視圖。 IS) -33- 1360526 第6圖係說明依據本發明的第1實施型態之緩衝層形 成裝置之緩衝層的形成方法之側視說明圖。 第7圖係顯示本發明的第2實施型態之板玻璃之製造 設備中所具備之緩衝層形成裝置之立體圖。 第8圖係顯示本發明的第2實施型態之緩衝層形成裝 置的特取部分之立體圖。 【主要元件符號說明】 1 :熔融金屬浴槽 1 b :浴面 3 :徐冷爐 3a:徐冷爐的入口 5 :熔融玻璃 6 :玻璃帶 6a :玻璃帶的下表面 1 1、3 1 :形成裝置（形成手段） 12 :拉出電極 1 3、52 :帶電電極 14、53:帶電化保持容器 41 :保持容器 5 1 :帶電化裝置 6 1 :供應管 B :緩衝層 Μ :疵點產生防止劑 ί S] -34-As shown in the first table, Examples 1 to 9 show that the frequency of occurrence of defects is equal to or less than that of Comparative Example 1 of the conventional example, and it is known that the defect generation prevention effect is good. Further, in Examples 1 to 9, it was confirmed that the friction coefficient and the frequency of occurrence of the defects were inversely proportional to the adhesion amount of the particles, and in particular, the adhesion amount and the current amount had a high correlation. Further, at the time of the formation of the buffer layer, the malfunction of the missing detector provided in the rear stage of the quenching furnace was not caused, and the attached buffer layer was simply removed by washing, and the inside of the quench furnace was not confirmed. Contamination, therefore, by the present invention, the buffer layer can be formed without using the conventional S 02, so that the device is not corroded and the malfunction of the detector is not caused by the missing device S I -32 - 1360526. Can suppress the occurrence of defects. Further, in the present invention, the composition of the glass is not particularly selected. Therefore, a buffer layer can be formed on the plate glass for liquid crystal display of the alkali-free glass, and generation of defects can be suppressed. Furthermore, it does not cause the malfunction of the missing detector set in the rear section of the cold furnace. Industrial Applicability: The present invention is applicable to a method for producing a sheet glass using a floating method, and is particularly suitable for a method for producing a high quality sheet glass using a floating method. The entire contents of the specification, the claims, the drawings and the abstract of the Japanese Patent Application No. 2007-097203, filed on Apr. 3, 2007, are hereby incorporated by reference. BRIEF DESCRIPTION OF THE DRAWINGS Fig. 1 is a schematic cross-sectional view showing a part of a manufacturing apparatus for a sheet glass according to a first embodiment of the present invention. Fig. 2 is a perspective view showing a buffer layer forming apparatus provided in a manufacturing apparatus for a sheet glass according to a third embodiment of the present invention. Fig. 3 is a side view showing a buffer layer forming apparatus provided in the apparatus for manufacturing a sheet glass according to the first embodiment of the present invention. Fig. 4 is a perspective view showing a specific portion of the buffer layer forming apparatus of the first embodiment of the present invention. Fig. 5 is a front elevational view showing a specific portion of the buffer layer forming apparatus of the first embodiment of the present invention. IS) -33 - 1360526 Fig. 6 is a side elevational view showing a method of forming a buffer layer of the buffer layer forming apparatus according to the first embodiment of the present invention. Fig. 7 is a perspective view showing a buffer layer forming apparatus provided in a manufacturing apparatus for a sheet glass according to a second embodiment of the present invention. Fig. 8 is a perspective view showing a specific portion of the buffer layer forming device of the second embodiment of the present invention. [Description of main components] 1 : Molten metal bath 1 b : Bath surface 3 : Xu cold furnace 3a : Entrance of Xu cold furnace 5 : Molten glass 6 : Glass ribbon 6a : Lower surface of glass ribbon 1 1 , 3 1 : Forming means (formation means 12: Pull-out electrode 1 3, 52: charged electrode 14, 53: electrification holding container 41: holding container 5 1 : charging device 6 1 : supply tube B: buffer layer Μ : 产生 point generation preventing agent ί S] - 34-