TWI424977B - 製造含縮醛化聚乙烯醇之陶瓷生膜之方法 - Google Patents

製造含縮醛化聚乙烯醇之陶瓷生膜之方法 Download PDF

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TWI424977B
TWI424977B TW096116404A TW96116404A TWI424977B TW I424977 B TWI424977 B TW I424977B TW 096116404 A TW096116404 A TW 096116404A TW 96116404 A TW96116404 A TW 96116404A TW I424977 B TWI424977 B TW I424977B
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polyvinyl alcohol
weight
acetalized polyvinyl
alcohol
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TW200812933A (en
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Michael Frank
Robert Fuss
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Kuraray Europe Gmbh
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Description

製造含縮醛化聚乙烯醇之陶瓷生膜之方法 說明
本發明係關於縮醛化聚乙烯醇用於製造陶瓷生膜之用途及/或關於一種用於製造此等陶瓷生膜之方法。
 技術領域
用於電子工業之陶瓷材料時常係經由所謂生膜(即包含陶瓷材料之相似於膜，薄之塑造物體)之燒結而製造。對於此等生膜之製造，首先使用塑化劑及分散劑以製造金屬氧化物與有機溶劑之懸浮液。隨後經由適合之方法(即刮刀片方法)而將此種懸浮液以需要之厚度塗敷於載體膜上，及移除溶劑。如此獲得之生膜必須不含裂縫、顯示平滑之表面並且仍然具有某些彈性。
技藝之技術發展水準
時常使用魚油、聚丙烯酸酯或某些聚乙烯縮醛諸如聚乙烯丁醛作為用於製造陶瓷生膜之黏合劑及/或分散劑。因此德國專利4 003 198 A1敘述用於陶瓷生膜之澆注用泥漿之製造，其中使用具有0至2重量%之殘餘聚醋酸乙烯酯含量之聚乙烯丁醛作為黏合劑。以相似之方法，德國專利3 724 108 A1揭示聚乙烯丁醛之使用，殘餘醋酸乙烯酯含量係0.5至3.0重量%。
然而，於此處敘述之聚乙烯丁醛顯示低之分散性，及充當暫時之黏合劑以保證需要之生膜之撓性。以此種方法獲得之懸浮液顯示僅相對地低之固體之比例。
自不同之技術領域，即印刷墨水及油漆之製造，具有較高之殘餘醋酸酯含量之聚乙烯丁醛之使用係已為吾人所知的(德國專利198 16 722 A1)。此外，德國專利1545135 A1揭示具有8%之殘餘醋酸酯含量之聚乙烯丁醛用於製造分散液之用途。
前述之文獻係關於分散有機顏料及/或其本身之分散液之方法，及不是關於陶瓷粉末之懸浮液或陶瓷生膜之製造。
於美國專利6,211,289中，敘述於懸浮液中之乙烯醇與1－烷基乙烯醇之縮醛化之共聚物用於製造生膜之用途。可能為了調節懸浮液之適合之黏度，此等化合物顯示<5重量%之殘餘醋酸酯含量。此外，來自乙烯醇與1－烷基乙烯醇之共聚物之製造係複雜的。
 目的
於是，本發明之目的係由提供用於製造陶瓷生膜之懸浮液之黏合劑或分散劑構成，該等黏合劑或分散劑顯示高之分散效應及保證該懸浮液之高之固體含量同時具有低黏度。
充分令人驚訝地，已發現，對於陶瓷懸浮液之製造及因此對於陶瓷生膜之製造，具有高之殘餘聚醋酸乙烯酯含量之聚乙烯縮醛係很適合於作為黏合劑或分散劑。
本發明之目的
於是本發明之目的係由提供用於製造陶瓷生膜或陶瓷塑造物體之縮醛化聚乙烯醇之用途構成，該縮醛化聚乙烯醇顯示8至50重量%之聚醋酸乙烯酯含量及100至1200之聚合度。
根據本發明使用之縮醛化聚乙烯醇完全係由乙烯醇單位組成，不含1－烷基乙烯醇單位。較佳地，彼等顯示10至50重量%，特別較佳地10至30重量%，特定言之10至20重量%或14至18重量%之聚醋酸乙烯酯含量。
此外，縮醛化聚乙烯醇可顯示10至35重量%，較佳地11至27重量%及特定言之16至21重量%之聚乙烯醇含量。
縮醛化聚乙烯醇之聚合度較佳地係於100與1000之間，特別較佳地於100與800之間及特定言之於100與500之間。
較佳地，使用之縮醛化聚乙烯醇顯示2至500毫帕秒(mPas)，特別較佳地2至200毫帕秒，特定言之2至125毫帕秒或2至75毫帕秒之根據DIN 53015(於乙醇中之10%溶液，於20℃，於Hoeppler黏度計中)測定之黏度。
根據本發明使用之縮醛化聚乙烯醇可係以完全或部分縮醛化之狀態使用，具有15至80重量%(特定言之20至60重量%)之縮醛化作用程度之部分縮醛化之聚乙烯醇之使用係較佳的。根據本發明使用之縮醛化聚乙烯醇之縮醛化作用程度亦係自100%與聚醋酸乙烯酯含量加上聚乙烯醇含量比較之差異測定(於每種情況中以重量%表示)。
對於聚乙烯醇之縮醛化作用，可使用一種或數種來自甲醛、乙醛、丙醛、丁醛、異丁醛、戊醛、己醛、庚醛、辛醛、壬醛、異壬醛或癸醛之族群之醛。較佳地，使用丁醛以用於縮醛化作用，致使較佳地轉而使用聚乙烯丁醛以用於製造生膜。
理論上，專家熟諳縮醛化聚乙烯醇之製造，及其係經由對應之聚乙烯醇之以酸催化之縮醛化作用而進行。於德國專利19 816 722 A1中揭示之聚乙烯丁醛及/或彼等之製造方法係特別適合的。對於適合於根據本發明之用途之聚乙烯乙醛(polyvinyl acetals)及/或聚乙烯丁醛之製造，特定地參考此文件。
此外，本發明之目的係由用於經由塑製及乾燥包含無機顏料、有機溶劑、黏合劑、塑化劑及分散劑之懸浮液而製造陶瓷生膜或陶瓷塑造物體之方法構成，其中使用具有8至50重量%之聚醋酸乙烯酯含量或其他前述之聚醋酸乙烯酯含量及100至1200之聚合度之縮醛化聚乙烯醇作為分散劑。
較佳地，根據本發明製造之懸浮液包含0.1至10重量%，較佳地1至8重量%，特別較佳地2至6重量%，特定言之0.1至2重量%之所謂縮醛化聚乙烯醇。
關於陶瓷生體之製造，應參考前述之文獻。通常，首先以有機溶劑(諸如例如甲醇、甲苯、甲基乙基酮(MEK)、石蠟或異丙醇或此等之混合物)將一種或數種無機顏料(諸如例如Al2 O3 、BaTiO3 、鎢氧化物、ZrO2 、TiO2 或氮化鋁)懸浮。將分散劑諸如魚油及/或前述之縮醛化聚乙烯醇加入此種懸浮液中。隨後，將一種或數種塑化劑加入該懸浮液中，及於數小時之過程中均質化。
較佳地，使用酞酸酯(諸如酞酸二辛酯、酞酸二丁酯或酞酸苄基丁基酯)、己二酸酯、聚乙二醇、磷酸酯、檸檬酸酯或經酯化之聚乙二醇諸如3G7或3G8作為塑化劑。
用於懸浮液之製造，根據本發明之方法因此可包含下列階段：－將無機材料(顏料)懸浮於有機溶劑中－分散劑之添加－視需要：使無機材料於溶劑與分散劑之混合物中之發泡－懸浮液之均質化－塑化劑之添加－黏合劑之添加，視需要，該黏合劑係與分散劑完全相同－懸浮液之均質化。
根據本發明之使用及/或根據本發明之方法致使，以所謂縮醛化聚乙烯醇大量地或完全地取代通常作為分散劑使用之材料變成可能。較佳地，使用以至少50重量%(特定言之75%及特別地100%)之比例包含上述之縮醛化聚乙烯醇之分散劑混合物。
組合入懸浮液中之聚合之黏合劑係，例如，由標準聚乙烯丁醛、聚丙烯酸酯及/或上述之縮醛化聚乙烯醇(本身或於混合物中)組成。適合作為標準聚乙烯丁醛者係，例如，來自Kuraray Europe GmbH之種類Mowital B20H、B45H、B45M、B60、B60H或B75。此等標準聚乙烯丁醛之聚醋酸乙烯酯含量係1至4重量%。
特定言之，使用一種或數種標準聚乙烯丁醛與一種或數種上述之縮醛化聚乙烯醇之混合物係可能的，標準聚乙烯丁醛之比例係低於50重量%(即於0與50重量%之間)，較佳地低於25重量%(即於0與25重量%之間)及特定言之於0與10重量%之間。
於本發明之一種變異形式中，使用僅上述之縮醛化聚乙烯醇作為黏合劑，而且無其他之聚合之黏合劑。
於本發明之另一種變異形式中，使用僅上述之縮醛化聚乙烯醇作為分散劑及作為黏合劑，而且無另外之聚合之黏合劑或分散劑。
如此獲得之懸浮液係於適合之混合機諸如例如球磨粉機中均質化。已經由使用縮醛化聚乙烯醇而製造之懸浮液係以特別低之黏度連同分散劑之同樣地低之濃度為特徵。對應地，懸浮液可具有高比例之固體連同低之黏度，其巨量地促成於連續製造設施中該懸浮液之加工成為陶瓷生膜。
 實例
測定之方法a)聚醋酸乙烯酯含量之測定 應瞭解，聚醋酸乙烯酯含量意表以重量%表示之乙醯基之比例，該乙醯基係自對於1克物質之皂化作用所必需之氫氧化鉀溶液之消耗所生成。
測定之方法(以EN ISO 3681為基礎)將精確地稱重至1毫克之約2克之受研究之物質加入500毫升圓底燒瓶中，及於回流下溶解於90毫升之乙醇與10毫升之苄醇中。於冷卻後，對照於酚酞，以0.01 N之NaOH中和該溶液。隨後，將25.0毫升之0.1 N之KOH加入，及於回流下進行加熱歷時1.5小時。然後容許該燒瓶於密閉之狀態中冷卻，及於酚酞作為指示劑之對照下，以0.1 N之氫氯酸滴定過量之液體，直到獲得永久之變色為止。以相同之方法處理對照樣本。聚醋酸乙烯酯含量係如下計算：以[%]表示之聚醋酸乙烯酯含量＝(b－a)* 86/E，其中a＝以毫升表示之用於樣本之0.1 N之KOH之消耗量，b＝以毫升表示之用於對照樣本試驗之0.1 N之KOH之消耗量及E＝以克表示之受檢查之物質於乾燥狀態中稱重加入之數量。
b)聚乙烯醇基之含量之測定 聚乙烯醇基之含量(聚乙烯醇含量)係羥基之比例，其係經由以乙酐之隨後縮醛化作用而可檢測出。
測定之方法(以DIN 53240為基礎)將精確地稱重至1毫克之約1克之Mowital加入300毫升圓底錐形燒瓶中，將10.0毫升之乙酐吡啶混合物(23：7體積/體積)加入，及加熱此至50℃歷時15－20小時。於冷卻之後，將17毫升之1,2－二氯乙烷加入，及短暫地旋轉。隨後，於攪拌下將8毫升之水加入，以塞子封閉該燒瓶，及進行攪拌歷時10分鐘。以50毫升之去離子水清洗燒瓶之頸部及塞子，以5毫升之正丁醇覆蓋，及對照於酚酞，以1 N之燒鹼溶液滴定自由態醋酸。以相同之方法處理對照樣本。聚乙烯醇含量係如下計算：聚乙烯醇含量[%]＝(b－a)* 440/E，其中a＝以毫升表示之用於樣本之1 N之NaOH之消耗量，b＝以毫升表示之用於對照樣本之1 N之NaOH之消耗量及E＝以克表示之受檢查之物質於乾燥狀態中稱重加入之數量。
c)黏度之測定 使用之聚乙烯縮醛之黏度係根據DIN 53015對於乙醇中之10%溶液於20℃於Hoeppler黏度計中測定。
d)聚合度之測定 聚合度可係對於聚乙烯醇較容易地測定，及於縮醛化作用中不改變。使用聚乙烯丁醛作為實例，聚合度係根據下列式計算
係經由與靜止光散射(絕對方法)結合之對於經再縮醛化樣本之膠透層析術(GPC)而進行。對於之值之精確度係測定為±15%。
水解度(DH[莫耳%])係根據下列式計算：
酯值(EV)係如下列及使用下列式測定： 其中a＝0.1 N之KOH之消耗量[毫升]，b＝用於對照樣本之0.1 N之KOH之消耗量[毫升]，E＝稱重加入之聚乙烯醇之精確數量。
將約1克之聚乙烯醇引進入250毫升圓底燒瓶中，及將70毫升之蒸餾水及30毫升之經中和之醇加入，及於回流下加熱直到聚乙烯醇已完全溶解為止。於冷卻後，對照於酚酞，以0.1 N之KOH進行滴定直到中性。當已完成中和作用時，將50毫升之0.1 N之KOH加入，及於回流下加熱此混合物歷時1小時。對照於作為指示劑之酚酞，於加熱中以0.1 N之HCl逆滴定過量之液體，直到溶液之顏色不再回復為止。同時，以對照樣本進行該試驗。
比較實例(根據技藝之技術發展水準之黏合劑，所有皆來自Kuraray Europe GmbH)1)具有約600之聚合度之Mowital B45H 2)具有約800之聚合度之Mowital B60H 3)具有約400之聚合度之Mowital B20H。
實例1使用之黏合劑：根據德國專利19 816 722 A1具有約800之聚合度、具有20.2重量%之聚乙烯醇含量、16.1%之聚醋酸乙烯酯含量及122.5毫帕秒之於乙醇中之10%溶液於20℃根據DIN 53015之於Hoeppler黏度計中測定之黏度之聚乙烯丁醛。
實例2使用之黏合劑：根據德國專利19 816 722 A1具有約1100之聚合度、具有20.7重量%之聚乙烯醇含量、16.2%之聚醋酸乙烯酯含量及275毫帕秒之於乙醇中之10%溶液於20℃根據DIN 53015之於Hoeppler黏度計中測定之黏度之聚乙烯丁醛。
實例3使用之黏合劑：根據德國專利19 816 722 A1具有約350之聚合度、具有19.6重量%之聚乙烯醇含量、19.4%之聚醋酸乙烯酯含量及20.8毫帕秒之於乙醇中之10%溶液於20℃根據DIN 53015之於Hoeppler黏度計中測定之黏度之聚乙烯丁醛。
使用之另外材料
懸浮液性質之評估
a)黏合劑溶液之流變學之行為 測量方法：對於流變學性質之測定，分別地製造聚乙烯丁醛(PVB)於乙醇/甲苯之溶劑混合物中之10質量%之溶液，及於滾轉混合機中均質化該等溶液歷時24小時。
根據測量之錐與板原理(錐直徑50毫米，開口角2度)使用來自Anton Paar(澳洲)之旋轉流變計UDS 200而進行流變學之描述。旋轉錐之控制係經由剪應力控制而進行，測量溫度係20℃。黏度係對於剪應力繪圖。
結果及評估：圖1、4及6顯示，與20帕＊ 秒之剪應力相關之黏合劑溶液之平均黏度，於整個測量範圍內該等黏合劑溶液顯示固定之黏度(牛頓型行為)。下列之表表示，相關於以上數值之測量數據。
具有根據本發明具有根據實例1、2及3之高聚醋酸乙烯酯含量之聚乙烯丁醛(PVB)之溶液顯示比該等比較之物質B20H、B45H及B60H較高之溶液黏度。
b)PVB－Al 2 O 3 懸浮液之流變學 測量之方法：為了評估聚乙烯丁醛(PVB)黏合劑之分散效果，製備不同之Al2 O3 懸浮液(40重量%之乙醇/甲苯，60重量%之Al2 O3 )。逐步地將相關之聚乙烯丁醛黏合劑及/或分散劑加入此等懸浮液中，及均質化歷時若干小時。用於膜之製造，首先將分散劑(於此案例中聚乙烯丁醛)預溶解於溶劑中，然後將粉末加入。相關之懸浮液係藉旋轉黏度計而描述。對於此目的，使用於100磅/秒(l/s)之剪切速率之懸浮液黏度作為比較值。
結果及評估：圖2、3、5及7顯示不同之懸浮液之黏度，如懸浮液之固體含量之函數。於與時常作為分散劑使用之魚油比較中，使用之聚乙烯丁醛黏合劑具有降低之黏度。此外，由於對應地製備之懸浮液之黏度值係低於以Mowital類型製備之懸浮液者，因此於與比較之物質Mowital B20H、B45H及B60H比較中，獲得較佳之分散效果。
受研究之分散劑之分散性質之比較係於圖3、5及7中表示。分散效果愈佳，則相關之Al2 O3 懸浮液之黏度愈低。當使用具有高之聚醋酸乙烯酯含量之聚乙烯丁醛類型以替代B45H或魚油時，達成明確地較多之液體及因此較佳地分散之懸浮液。
生膜之製造
將如此獲得之懸浮液(澆注用泥漿(casting slip)除氣、及於具有固定之雙室塑製器具之4米長度之膜塑製設施中根據刮刀片方法塑製。使用已以矽處理之聚對酞酸乙二酯(PET)膜(厚度100微米)作為塑製支座。於塑製之後，膜係於空氣中乾燥歷時48小時(溫度＝22℃；大氣之濕度＝65%)及隨後抽出。
獲得之膜具有200微米之厚度及於光學評估中不顯示裂縫、起泡或瑕疵。
塑製之Al2 O3 膜之密度係經由根據阿幾米德原理(Archimedes)之浮力測量而測定。生膜密度皆係於對於在60與70%之間之理論厚度之膜塑製係標準之範圍之內。
自相關之生膜，鑽孔出於所謂〝狗骨頭(dog bones)〞形式之適合之拉伸試樣。每種種類之膜，於橫過於塑製之方向鑽孔出10個拉伸試樣及於平行於於塑製之方向鑽孔出10個拉伸試樣，俾能測定生體之可能之各向異性之行為。使用纖維拉伸試驗設備(Fafegraph ME,Textecho)作為試驗機器。測量之最大範圍係100牛頓，負荷之速率係10毫米/分鐘。測量係於室溫於周圍空氣中進行。
測定出與根據技藝之技術發展水準之生膜可比較之數值，此等數值表示於特性中，於根據本發明製造之膜與根據技藝之技術發展水準者之間無重大之差異。
於是，對於陶瓷生膜之製造，新穎之聚乙烯丁醛(PVB)類型係適合於作為分散劑及同時作為黏合劑。有利地，於懸浮液之製造之期間達成改良之分散效果及較高之固體含量，及因此達成值得注意之應用技術之利益。
圖1顯示與剪應力相關之黏合劑溶液之平均黏度。
圖2顯示懸浮液之黏度與固體含量之函數。
圖3顯示懸浮液之黏度與固體含量之函數。
圖4顯示與剪應力相關之黏合劑溶液之平均黏度。
圖5顯示懸浮液之黏度與固體含量之函數。
圖6顯示與剪應力相關之黏合劑溶液之平均黏度。
圖7顯示懸浮液之黏度與固體含量之函數。

Claims (14)

  1. 一種用於製造陶瓷生膜或陶瓷塑造物體之方法，該方法包括塑製及乾燥包含一或多種無機顏料、一或多種有機溶劑、一或多種黏合劑、一或多種塑化劑及一或多種分散劑之懸浮液，其中具有8至50重量%之醋酸乙烯酯含量及100至1200之聚合度w之縮醛化聚乙烯醇作為分散劑，其中該縮醛化聚乙烯醇不包含1-烷基乙烯基醇單元，其中該縮醛化聚乙烯醇具有10至35重量%之乙烯醇含量。
  2. 如請求項1之方法，其中該懸浮液包含0.1至10重量%之該縮醛化聚乙烯醇。
  3. 如請求項1之方法，其中該縮醛化聚乙烯醇具有100至1000之聚合度。
  4. 如請求項1之方法，其中該縮醛化聚乙烯醇具有2至500毫帕秒之根據DIN 53015測定之黏度。
  5. 如請求項1之方法，其中使用甲醛、乙醛、丙醛、丁醛、異丁醛、戊醛、己醛、庚醛、辛醛、壬醛、異壬醛或癸醛中之一種或數種醛以用於該聚乙烯醇之縮醛化作用。
  6. 如請求項1之方法，其中使用聚乙烯丁醛作為該縮醛化聚乙烯醇。
  7. 如請求項1之方法，其中該縮醛化聚乙烯醇具有10至50重量%之乙烯醇含量。
  8. 如請求項1之方法，其中該縮醛化聚乙烯醇具有10至30重量%之乙烯醇含量。
  9. 如請求項1之方法，其中該縮醛化聚乙烯醇具有11至27重量%之乙烯醇含量。
  10. 如請求項1之方法，其中該縮醛化聚乙烯醇具有100至1000之聚合度。
  11. 如請求項1之方法，其中該縮醛化聚乙烯醇具有2至200毫帕秒之黏度，係在20℃下於乙醇中之10%溶液測量。
  12. 如請求項1之方法，其中該縮醛化聚乙烯醇具有10至50重量%之醋酸乙烯酯含量，及10至35重量%之乙烯醇含量。
  13. 如請求項1之方法，其中該縮醛化聚乙烯醇有20至60重量%之縮醛化程度。
  14. 一種用於製造陶瓷生膜或陶瓷塑造物體之方法，該方法包括塑製及乾燥懸浮液，其中改善為該懸浮液包含作為分散劑之具有8至50重量%之醋酸乙烯酯含量及100至1200之聚合度w之縮醛化聚乙烯醇作為分散劑，其中該縮醛化聚乙烯醇不包含1-烷基乙烯基醇單元。
TW096116404A 2006-05-10 2007-05-09 製造含縮醛化聚乙烯醇之陶瓷生膜之方法 TWI424977B (zh)

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EP07106006A EP1854772B1 (de) 2006-05-10 2007-04-12 Verfahren zur Herstellung von keramischen Grünfolien mit acetalisierten Polyvinylalkoholen

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Families Citing this family (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2010113628A1 (ja) * 2009-03-31 2010-10-07 積水化学工業株式会社 スラリー組成物の製造方法
JP5698750B2 (ja) * 2010-08-19 2015-04-08 株式会社クラレ ポリビニルアセタール樹脂、そのスラリー組成物、セラミックグリーンシート及び積層セラミックコンデンサ
KR101886458B1 (ko) 2010-09-29 2018-08-07 세키스이가가쿠 고교가부시키가이샤 슬러리 조성물의 제조 방법
TWI557096B (zh) * 2011-09-28 2016-11-11 可樂麗股份有限公司 漿料組成物、陶瓷坯片及積層陶瓷電容器
EP2851355A1 (de) * 2013-09-18 2015-03-25 Kuraray Europe GmbH Verwendung von Polyvinylisoacetalen für Keramikformulierungen
JP2019178389A (ja) * 2018-03-30 2019-10-17 株式会社フジミインコーポレーテッド 溶射用スラリー
EP4183761A1 (en) * 2021-11-18 2023-05-24 Kuraray Europe GmbH Use of compacted polyvinyl acetals as binder in ceramic green sheets

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW492985B (en) * 1996-10-04 2002-07-01 Wacker Chemie Gmbh Modified polyvinyl acetals
JP2003192449A (ja) * 2001-12-27 2003-07-09 Tdk Corp 水系セラミックグリーンシート用塗料組成物、セラミックグリーンシートの製造方法およびセラミック電子部品の製造方法
US20060014049A1 (en) * 2003-05-19 2006-01-19 Matsushita Electric Industrial Co., Ltd Ceramic green sheet, laminated ceramic article, and process for producing the same

Family Cites Families (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE4003198A1 (de) * 1990-02-03 1991-08-08 Hoechst Ceram Tec Ag Giessmasse zur herstellung keramischer gruenfolien und ihre verwendung
JP3306112B2 (ja) * 1992-09-11 2002-07-24 株式会社日立製作所 ポリビニルアセタール系樹脂、その製法及びこれを用いたセラミックシート
JP3320615B2 (ja) * 1996-08-26 2002-09-03 積水化学工業株式会社 セラミックグリーンシート用スラリー組成物
DE19816722A1 (de) * 1998-04-16 1999-10-21 Clariant Gmbh Druckfarben und Lacke enthaltend Polyvinylbutyrale basierend auf teilverseiften Polyvinylalkoholen
JP2005082437A (ja) * 2003-09-08 2005-03-31 Matsushita Electric Ind Co Ltd セラミックグリーンシートおよびそれを用いた積層セラミック電子部品

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
TW492985B (en) * 1996-10-04 2002-07-01 Wacker Chemie Gmbh Modified polyvinyl acetals
JP2003192449A (ja) * 2001-12-27 2003-07-09 Tdk Corp 水系セラミックグリーンシート用塗料組成物、セラミックグリーンシートの製造方法およびセラミック電子部品の製造方法
US20060014049A1 (en) * 2003-05-19 2006-01-19 Matsushita Electric Industrial Co., Ltd Ceramic green sheet, laminated ceramic article, and process for producing the same

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