JP3761915B2 - Ceramic molding composition - Google Patents

Description

【００１２】
前記アセチレンアルコールとしては、ｎ＝１の時、ジメチルヘキシノール〔ＣＨ≡Ｃ−Ｃ（ＣＨ₃ ）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）₂ 〕、ジメチルプロパルギルアルコール〔ＣＨ≡Ｃ−Ｃ（ＣＨ₃ ）₂ （ＯＨ）〕、エチルメチルプロパルギルアルコール〔ＣＨ≡Ｃ−Ｃ（ＣＨ₃ ）（ＯＨ）Ｃ₂ Ｈ₅ 〕、メチルプロピルプロパルギルアルコール〔ＣＨ≡Ｃ−Ｃ（ＣＨ₃ ）（ＯＨ）Ｃ₃ Ｈ₇ 〕、イソブチルメチルプロパルギルアルコール〔ＣＨ≡Ｃ−Ｃ（ＣＨ₃ ）（ＯＨ）ＣＨ₂ ＣＨ−（ＣＨ₃ ）₂ 〕等が挙げられる。
【００１３】
また、ｎ＝２の時は、メチルエチルヘキシノール〔ＣＨ≡Ｃ−Ｃ（Ｃ₂ Ｈ₅ ）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）ＣＨ₃ 〕が、ｎ＝３の時は、メチルプロピルヘキシノール〔ＣＨ≡Ｃ−Ｃ（Ｃ₃ Ｈ₇ ）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）ＣＨ₃ 〕が、ｎ＝４の時は、メチルブチルヘキシノール〔ＣＨ≡Ｃ−Ｃ（Ｃ₄ Ｈ₉ ）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）ＣＨ₃ 〕が、ｎ＝５の時は、メチルペンチルデシノール〔ＣＨ≡Ｃ−Ｃ（Ｃ₅ Ｈ₁₁）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）Ｃ₅ Ｈ₁₁〕が、ｎ＝６の時は、メチルヘキシルデシノール〔ＣＨ≡Ｃ−Ｃ（Ｃ₆ Ｈ₁₃）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）Ｃ₅ Ｈ₁₁〕が、ｎ＝７の時は、メチルヘプチルデシノール〔ＣＨ≡Ｃ−Ｃ（Ｃ₇ Ｈ₁₅）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）Ｃ₅ Ｈ₁₁〕が、ｎ＝８の時は、メチルオクチルデシノール〔ＣＨ≡Ｃ−Ｃ（Ｃ₈ Ｈ₁₇）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）Ｃ₅ Ｈ₁₁〕等が挙げられる。
【００１４】
また、アセチレングリコールとは、アセチレン結合と、アルキンの三重結合に隣接する２個の炭素原子に各々１個の水酸基を有する次式で表される化合物である。
【００１５】
【数２】

【００１６】
前記アセチレングリコールとしては、ｎ＝１の時、ヘキシンジオール〔ＣＨ₃ ＣＨ（ＯＨ）−Ｃ≡Ｃ−ＣＨ（ＯＨ）ＣＨ₃ 〕、ジメチルヘキシンジオール〔ＣＨ₃ Ｃ（ＣＨ₃ ）（ＯＨ）−Ｃ≡Ｃ−Ｃ（ＣＨ₃ ）（ＯＨ）ＣＨ₃ 〕、ジメチルオクチンジオール〔Ｃ₂ Ｈ₅ Ｃ（ＣＨ₃ ）（ＯＨ）−Ｃ≡Ｃ−Ｃ（ＣＨ₃ ）（ＯＨ）Ｃ₂ Ｈ₅ 〕、ジメチルデシンジオール〔Ｃ₃ Ｈ₇ Ｃ（ＣＨ₃ ）（ＯＨ）−Ｃ≡Ｃ−Ｃ（ＣＨ₃ ）（ＯＨ）Ｃ₃ Ｈ₇ 〕、ジメチルドデシンジオール〔Ｃ₄ Ｈ₉ Ｃ（ＣＨ₃ ）（ＯＨ）−Ｃ≡Ｃ−Ｃ（ＣＨ₃ ）（ＯＨ）Ｃ₄ Ｈ₉ 〕、ジメチルテトラデシンジオール〔Ｃ₅ Ｈ₁₁Ｃ（ＣＨ₃ ）（ＯＨ）−Ｃ≡Ｃ−Ｃ（ＣＨ₃ ）（ＯＨ）Ｃ₅ Ｈ₁₁〕、テトラメチルデシンジオール〔ＣＨ₃ ＣＨ（ＣＨ₃ ）ＣＨ₂ Ｃ（ＣＨ₃ ）（ＯＨ）−Ｃ≡Ｃ−Ｃ（ＣＨ₃ ）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）ＣＨ₃ 〕が、ｎ＝２の時、ジメチルジエチルデシンジオール〔ＣＨ₃ ＣＨ（ＣＨ₃ ）ＣＨ₂ Ｃ（Ｃ₂ Ｈ₅ ）（ＯＨ）−Ｃ≡Ｃ−Ｃ（Ｃ₂ Ｈ₅ ）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）ＣＨ₃ 〕が、ｎ＝３の時、ジメチルジプロピルデシンジオール〔ＣＨ₃ ＣＨ（ＣＨ₃ ）ＣＨ₂ Ｃ（Ｃ₃ Ｈ₇ ）（ＯＨ）−Ｃ≡Ｃ−Ｃ（Ｃ₃ Ｈ₇ ）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）ＣＨ₃ 〕が、ｎ＝４の時、ジメチルジブチルデシンジオール〔ＣＨ₃ ＣＨ（ＣＨ₃ ）ＣＨ₂ Ｃ（Ｃ₄ Ｈ₉ ）（ＯＨ）−Ｃ≡Ｃ−Ｃ（Ｃ₄ Ｈ₉ ）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）ＣＨ₃ 〕が、ｎ＝５の時、ジメチルジベンチルオクタデシンジオール〔Ｃ₅ Ｈ₁₁ＣＨ（ＣＨ₃ ）ＣＨ₂ Ｃ（Ｃ₅ Ｈ₁₁）（ＯＨ）−Ｃ≡Ｃ−Ｃ（Ｃ₅ Ｈ₁₁）（ＯＨ）ＣＨ₂ ＣＨ（ＣＨ₃ ）Ｃ₅ Ｈ₁₁〕等が挙げられる。
【００１７】
更に、アセチレングリコールのアルキレンオキサイド付加物とは、次式で表されるものである。
【００１８】
【数３】

【００１９】
前記アセチレングリコールのアルキレンオキサイド付加物としては、−（ＯＡ）_n 、−（ＯＡ）_m がＯＥ、ＯＰの単重合体、またはＯＥ、ＯＰの共重合体が好ましく、各種アルキレンオキシドの付加物は公知の方法で合成することができるものである。
【００２０】
また、本発明では、セラミック原料粉末としてチタン酸バリウム（ＢａＴｉＯ_３ ）に適用でき、前記セラミック原料粉末には各種焼結助剤を所望量添加させることもできる。
【００２１】
尚、これらセラミック原料粉末の粒径は、数十μｍ乃至サブミクロンのものが好適に用いることができる。
【００２２】
また、セラミック原料粉末の分散性の向上のために、前記原料粉末にはシランカップリング剤、チタネートカップリング剤、アルミネートカップリング剤等のカップリング剤を用いて表面改質したものを使用することもできる。
【００２３】
一方、セラミックグリーンシートは十分な強度と柔軟性を保持しなければならないため、有機性添加物として、バインダーとしての各種樹脂や分散剤等が種々組み合わせて使用される。
【００２４】
前記樹脂としては、マレイン酸系樹脂、セルロース系樹脂、ロジン系樹脂、石油系樹脂、ポリビニール系樹脂、ブチラール樹脂、ポリエステル樹脂、アクリル樹脂、エポキシ樹脂、ポリアミド樹脂、ポリウレタン系樹脂、アルキッド樹脂、ポリアマイド樹脂等があり、該樹脂を単独もしくは複数で用いられる。
【００２５】
また、分散剤は、一般にセラミックスの調合に用いられる任意の界面活性剤をもちいることができるが、とりわけポリオキシアルキルカルボン酸アンモニウム塩や、ポリオキシアルキル燐酸エステル塩、ナフタレンスルホン酸塩ホルマリン縮合体等が挙げられる。
【００２６】
また、溶媒は用いる有機性添加物と相溶するものであれば、特に限定するものではなく、例えば、トルエン、キシレン、ベンゼン、ヘキサノール、デカノール、酢酸エステル、グリセライド等のアルコール類，炭化水素類，エステル類，エーテルアルコール類，ケトン類，塩化炭化水素類等が使用できる。
【００２７】
更に、所定量の有機性添加物と溶媒の均一溶液を調製する際、必要に応じて助剤として界面活性剤、可塑剤、静電気防止剤、消泡剤、酸化防止剤、滑剤、硬化剤等を適宜用いることができる。
【００２８】
また、前記均一溶液にする攪拌手段は特に限定するものではないが、一般のボールミル、攪拌機、ヘンシェルミキサー等を用いることができる。
【００２９】
得られた溶液にセラミック原料粉末を添加混合して調製するが、セラミック原料粉末の添加方法は特に限定するものではなく、均一な混合物に最終的になれば良く、十分に攪拌した後、脱泡処理をすることが肝要である。
【００３０】
【作用】
本発明のセラミック成形用組成物によれば、分子内に一個の三重結合を有するアセチレンアルコール、アセチレングリコール、アセチレングリコールのアルキレンオキサイド付加物の少なくとも一種を含有することから、セラミック泥漿の表面張力が低くなり、帯状のキャリアフィルムへのセラミック泥漿の濡れ性が良好となり、ドクターブレード法では、膜厚が１０μｍ以上の塗膜欠陥のない均一なセラミックグリーンシートを得ることができ、特にアセチレングリコールのエチレンオキサイド付加物は動的表面張力が低いので、高速印刷が可能なグラビア印刷や、スクリーン印刷、フレキソ印刷、オフセット印刷等にも適合でき、厚さが数μｍの均一な薄膜を得ることが可能となる。
【００３１】
【実施例】
以下、本発明のセラミック成形用組成物を実施例に基づき詳細に説明する。
【００３２】
セラミック原料粉末としてチタン酸バリウム（ＢａＴｉＯ₃ ）１００重量部と、分散剤としてノニオン系界面活性剤を１．０重量部、可塑剤としてフタル酸ジオクチルを０．３重量部、溶媒としてセロソルブを３５重量部とを、ジルコニア製の直径約１ｍｍのボールと共にボールミル内に投入し、約６０時間にわたって湿式混合して泥漿を得た。尚、前記泥漿の平均粒径を測定したところ、約０．１μｍの超微粒子が得られた。
【００３３】
更に、前記泥漿１００重量部に、バインダーをセラミック原料粉末に対して６重量部と、表１及び表２に示す添加剤とを２重量部加えてヘンシェルミキサーにて約１時間撹拌して評価用のセラミック成形用組成物を調製した。
【００３４】
尚、前記添加剤の量が０．１重量部未満では、均一な濡れ性の効果が発揮されず、一方、１０重量部を越えると動的表面張力が高くなり、良好な印刷適性を付与させることが困難となる。
【００３５】
従って、前記添加剤の量は、０．１〜１０重量部、とりわけ２〜４重量部が好ましい。
【００３６】
かくして得られた評価用のセラミック成形用組成物を用いて、グラビア印刷により厚さ約２０μｍのセラミックグリーンシートを作製した。尚、印刷速度は４０ｍ／ｍｉｎとし、キャリアフィルムにはポリエステルフィルムを用いた。
【００３７】
以上の手順に従って作製したセラミックグリーンシートの表面状態を実体顕微鏡及び走査型電子顕微鏡で観察して、それぞれ塗布性及び平滑性を評価した。
【００３８】
塗布性の評価は、実体顕微鏡で前記セラミックグリーンシートの下から照射光を当て、反対側から８０倍の倍率でセラミックグリーンシート１ｍｍ² 当たりのピンホール等の塗膜欠陥の個数を読み取り、塗膜欠陥が全く認められないものを○、塗膜欠陥が１個以上認められるものを×で評価した。
【００３９】
一方、平滑性の評価は、走査型電子顕微鏡によりセラミックグリーンシートの破断面から膜厚の寸法精度を測定し、膜厚の精度が１１％未満のものを●、１１％以上〜２１％未満のものを○、２１％以上のものを×で評価した。
【００４０】
次に、前記セラミックグリーンシートにスクリーン印刷法で内部電極を形成し、該セラミックグリーンシートを５０枚積層して圧着し、該圧着体を約４００℃の温度で大気雰囲気中、脱バインダー処理した後、約１３００℃の温度で約２時間焼成した。
【００４１】
続いて、前記焼成体に外部電極を形成し、２．００mm×１．２５mm角で静電容量が１μＦである評価用の積層セラミックコンデンサを得た。
【００４２】
前記評価用の積層セラミックコンデンサに１００Ｖの直流電圧を印加してショート不良の発生数を調査し、ショート不良数が測定試料３００個中が１０個未満のものを●、１０個以上〜１６個未満のものを○、１６個以上のものを×で評価した。
【００４３】
尚、比較例として前記実施例と同一条件で、添加剤を使用しないもの及び添加剤として脂肪酸のエチレンオキシド付加物を用いたもので作製した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について、同様に評価した。
【００４４】
【表１】

【００４５】
【表２】

【００４６】
以上の結果から明らかなように、添加剤を用いない試料番号１では、ピンホール等のシート欠陥が認められ、かつ平滑性を損ない、ショート不良を発生し、また、脂肪酸のエチレンオキシド付加物を添加物とした試料番号２２は、塗布性は良いものの、平滑性が悪く、ショート不良を発生している。
【００４７】
それに対して、本発明のものは、いずれも満足すべき結果が得られているが、とりわけアセチレングリコールのアルキルオキシド付加物を含有するものが、塗布性及び平滑性が良好で、ショート不良数も激減していることが分かる。
【００４８】
尚、本実施例では、本発明のセラミック成形用組成物を積層セラミックコンデンサに適用した場合について詳述したが、何らこれに限定されるものではなく、セラミック多層配線基板等の他の電子部品についても適用可能である。
【００４９】
【発明の効果】
叙上の如く、本発明のセラミック成形用組成物は、分子内に一個の三重結合を有するアセチレンアルコール、アセチレングリコール、アセチレングリコールのアルキレンオキサイド付加物の少なくとも一種を含有することから、厚さが５０μｍ以下の極めて薄いセラミックグリーンシートを、ピンホール等のシート欠陥がなく、均質で優れた平滑性を有するものとすることができ、積層セラミックコンデンサ等に適用した場合には、ショート不良発生率を大幅に低減することができる[0001]
[Industrial application fields]
The present invention relates to a ceramic molding composition used for molding a thin-film ceramic green sheet applied to an electronic component such as a multilayer ceramic capacitor or a ceramic multilayer wiring board.
[0002]
[Prior art]
Conventionally, electronic components such as multilayer ceramic capacitors and ceramic multilayer wiring boards are all coated with a conductive paste on a ceramic green sheet by screen printing or the like to form a wiring layer, and a plurality of the ceramic green sheets are laminated. The sheet lamination method was used to sinter.
[0003]
The ceramic green sheet is generally made of alumina (Al ₂ O ₃ ), mullite (3Al ₂ O ₃ .2SiO ₂ ), nitriding according to the electrical and thermal characteristics required as a substrate material. A ceramic slurry is prepared by adding a binder comprising an organic additive and a solvent to various ceramic raw material powders such as aluminum (AlN) or barium titanate (BaTiO ₃ ), and the ceramic slurry is formed into a belt-like carrier film by a doctor blade method. It is prepared by continuously coating on the top and then drying.
[0004]
In recent years, various electronic components have become more and more demanding for light weight and downsizing. In order to satisfy these requirements, the sheet thickness per layer has been reduced, the number of layers has been further increased, and multilayer ceramic capacitors have been used. For this reason, in order to realize a smaller size and a larger capacity, a dielectric material having a high dielectric constant is used to further reduce the sheet thickness.
[0005]
However, with a conventional ceramic slurry, when trying to obtain a green sheet with a thin sheet thickness, sheet defects such as pinholes are likely to occur due to poor wettability with the carrier film of the support, and a uniform coating film can be formed. There was a limit to reducing the thickness of the ceramic green sheet.
[0006]
Therefore, a composition containing a monomer and a copolymer having an average molecular weight in the range of 40,000 to 150,000 in the binder as a ceramic slurry capable of reducing the thickness of the ceramic green sheet by solving the above problem. Has been proposed in Japanese Patent Laid-Open No. 6-206761.
[0007]
[Problems to be solved by the invention]
However, with the above composition, sheet defects such as pinholes are unlikely to occur until the thickness of the ceramic green sheet is about 50 μm, and although a uniform coating film can be formed, a thin film-like ceramic green having a thickness of less than 50 μm When a sheet is molded, it becomes difficult to obtain a molded body without any defects. For example, when a multilayer ceramic capacitor is produced using such a ceramic green sheet, there is a problem that the incidence of short-circuit defects is extremely high. It was.
[0008]
OBJECT OF THE INVENTION
The present invention has been made to solve the above-mentioned problems, and its purpose is to provide an extremely thin ceramic green sheet having a thickness of 50 μm or less and excellent in smoothness without causing sheet defects such as pinholes. Another object of the present invention is to provide a ceramic molding composition that can produce a ceramic green sheet and can reduce the incidence of short-circuit defects when applied to a multilayer ceramic capacitor.
[0009]
[Means for Solving the Problems]
The ceramic molding composition of the present invention contains at least one kind of acetylene alcohol having one triple bond in the molecule, acetylene glycol, and an alkylene oxide adduct of acetylene glycol, and has a thickness of 50 μm or less. the green sheet forming a composition obtained by mixing a ceramic raw material powder and an organic additive solvent.
[0010]
In the ceramic molding composition of the present invention, the acetylene alcohol having one triple bond in the molecule is a compound represented by the following formula having an unsaturated alcohol having a carbon-carbon triple bond acetylene bond in the molecule: It is.
[0011]
[Expression 1]

[0012]
As the acetylene alcohol, when n = 1, dimethylhexinol [CH≡C—C (CH ₃ ) (OH) CH ₂ CH (CH ₃ ) ₂ ], dimethylpropargyl alcohol [CH≡C—C (CH ₃ ) ₂ (OH)], ethyl methyl propargyl alcohol [CH≡C—C (CH ₃ ) (OH) C ₂ H ₅ ], methyl propyl propargyl alcohol [CH≡C—C (CH ₃ ) (OH) C ₃ H ₇ ], isobutyl methyl propargyl alcohol [CH≡C—C (CH ₃ ) (OH) CH ₂ CH— (CH ₃ ) ₂ ] and the like.
[0013]
When n = 2, methylethylhexinol [CH≡C—C (C ₂ H ₅ ) (OH) CH ₂ CH (CH ₃ ) CH ₃ ] is methylpropyl, and when n = 3, methylpropyl When hexynol [CH≡C—C (C ₃ H ₇ ) (OH) CH ₂ CH (CH ₃ ) CH ₃ ] is n = 4, methylbutylhexynol [CH≡C—C (C ₄ H ₉ ) (OH) CH ₂ CH (CH ₃ ) CH ₃ ], when n = 5, methylpentyldecinol [CH≡C—C (C ₅ H ₁₁ ) (OH) CH ₂ CH (CH ₃ ) When C ₅ H ₁₁ ] is n = 6, methylhexyldecinol [CH≡C—C (C ₆ H ₁₃ ) (OH) CH ₂ CH (CH ₃ ) C ₅ H ₁₁ ] is n = 7 when the methyl heptyl deci Nord _{[CH≡C-C (C 7 H 15} ) (OH) CH 2 CH (CH 3) C 5 H 11 ] is, when n = 8 is Mechiruoku Rudeshinoru _{[CH≡C-C (C 8 H 17} ) (OH) CH 2 CH (CH 3) C 5 H 11 ], and the like.
[0014]
In addition, acetylene glycol is a compound represented by the following formula having one hydroxyl group on each of two carbon atoms adjacent to the acetylene bond and the triple bond of alkyne.
[0015]
[Expression 2]

[0016]
As the acetylene glycol, when n = 1, hexynediol [CH ₃ CH (OH) —C≡C—CH (OH) CH ₃ ], dimethylhexynediol [CH ₃ C (CH ₃ ) (OH) -C≡C-C (CH ₃ ) (OH) CH ₃ ], dimethyloctynediol [C ₂ H ₅ C (CH ₃ ) (OH) -C≡C—C (CH ₃ ) (OH) C ₂ H ₅ ], dimethyl decynediol _{[C 3 H 7 C (CH 3} ) (OH) -C≡C-C (CH 3) (OH) C 3 H 7 ], dimethyl de decynediol [C ₄ H ₉ C (CH ₃ ) (OH) -C≡C—C (CH ₃ ) (OH) C ₄ H ₉ ], dimethyltetradecinediol [C ₅ H ₁₁ C (CH ₃ ) (OH) —C≡C—C (CH ₃ ) (OH) C ₅ H _11], tetramethyldecynediol _{[CH 3 CH (CH 3) CH} 2 C (CH 3) (OH _{-C≡C-C (CH 3) (} OH) CH 2 CH (CH 3) CH 3 ] is, when n = 2, the dimethyl diethyl decynediol _{[CH 3 CH (CH 3) CH} 2 C (C 2 H ₅ ) (OH) —C≡C—C (C ₂ H ₅ ) (OH) CH ₂ CH (CH ₃ ) CH ₃ ], when n = 3, dimethyldipropyldecynediol [CH ₃ CH (CH ₃ ) CH ₂ C (C ₃ H ₇ ) (OH) —C≡C—C (C ₃ H ₇ ) (OH) CH ₂ CH (CH ₃ ) CH ₃ ], when n = 4, dimethyldibutyldecynediol [CH ₃ CH (CH ₃ ) CH ₂ C (C ₄ H ₉ ) (OH) —C≡C—C (C ₄ H ₉ ) (OH) CH ₂ CH (CH ₃ ) CH ₃ ] is n = 5 Dimethyldipentyloctadecindiol [C ₅ H ₁₁ CH (CH ₃ ) CH ₂ C (C ₅ H ₁₁ ) (OH) -C≡C—C (C ₅ H ₁₁ ) (OH ) CH ₂ CH (CH ₃ ) C ₅ H ₁₁ ] and the like.
[0017]
Furthermore, the alkylene oxide adduct of acetylene glycol is represented by the following formula.
[0018]
[Equation 3]

[0019]
As the alkylene oxide adduct of acetylene glycol,-(OA) _n and-(OA) _m are preferably OE and OP homopolymers or OE and OP copolymers, and various alkylene oxide adducts are known. It can be synthesized by the method.
[0020]
Further, in the present invention, as a ceramic raw material powder can apply to the barium titanium acid (BaTiO _3), before the xenon ceramic raw material powder various sintering aids can also be added a desired amount.
[0021]
The ceramic raw material powder having a particle size of several tens of μm to submicron can be suitably used.
[0022]
In addition, in order to improve the dispersibility of the ceramic raw material powder, the raw material powder that has been surface-modified using a coupling agent such as a silane coupling agent, a titanate coupling agent, or an aluminate coupling agent is used. You can also.
[0023]
On the other hand, since ceramic green sheets must maintain sufficient strength and flexibility , various resins, dispersants and the like as binders are used in various combinations as organic additives.
[0024]
Examples of the resin include maleic resin, cellulose resin, rosin resin, petroleum resin, polyvinyl resin, butyral resin, polyester resin, acrylic resin, epoxy resin, polyamide resin, polyurethane resin, alkyd resin, and polyamide. There are resins and the like, and these resins are used alone or in plural.
[0025]
In addition, as the dispersant, any surfactant generally used for the preparation of ceramics can be used, and in particular, polyoxyalkyl carboxylic acid ammonium salt, polyoxyalkyl phosphate ester salt, naphthalene sulfonate formalin condensate. Etc.
[0026]
The solvent is not particularly limited as long as it is compatible with the organic additive to be used. For example, alcohols such as toluene, xylene, benzene, hexanol, decanol, acetate, glyceride, hydrocarbons, Esters, ether alcohols, ketones, chlorinated hydrocarbons, etc. can be used.
[0027]
Furthermore, when preparing a uniform solution of a predetermined amount of organic additive and solvent, as necessary, surfactants, plasticizers, antistatic agents, antifoaming agents, antioxidants, lubricants, curing agents, etc. Can be used as appropriate.
[0028]
Further, the stirring means for making the homogeneous solution is not particularly limited, but a general ball mill, a stirrer, a Henschel mixer or the like can be used.
[0029]
The resulting solution to the ceramic raw material powder Seisuru added and mixed tone, but the addition method of a ceramic raw material powder is not particularly limited, well if the final uniform mixture, after stirring sufficiently, leaving It is important to apply foam treatment.
[0030]
[Action]
According to the ceramic molding composition of the present invention, since it contains at least one kind of acetylene alcohol having one triple bond in the molecule, acetylene glycol, and an alkylene oxide adduct of acetylene glycol, the surface tension of the ceramic slurry is low. Therefore, the wetness of the ceramic slurry to the belt-like carrier film is improved, and the doctor blade method can obtain a uniform ceramic green sheet having a film thickness of 10 μm or more, and particularly ethylene oxide of acetylene glycol Since the adduct has a low dynamic surface tension, it can be applied to gravure printing capable of high-speed printing, screen printing, flexographic printing, offset printing, and the like, and a uniform thin film having a thickness of several μm can be obtained. .
[0031]
【Example】
Hereinafter, the ceramic molding composition of the present invention will be described in detail based on examples.
[0032]
100 parts by weight of barium titanate (BaTiO ₃ ) as a ceramic raw material powder, 1.0 part by weight of a nonionic surfactant as a dispersant, 0.3 part by weight of dioctyl phthalate as a plasticizer, and 35 parts of cellosolve as a solvent Were placed in a ball mill together with a zirconia ball having a diameter of about 1 mm and wet-mixed for about 60 hours to obtain a slurry. When the average particle size of the slurry was measured, ultrafine particles of about 0.1 μm were obtained.
[0033]
Furthermore, the on slip 100 parts by weight, and 6 parts by weight of Ba Indah the ceramic raw material powder, and stirred for about 1 hour in a Henschel mixer by adding the additives shown in Table 1 and Table 2, 2 parts by weight Evaluation A ceramic molding composition was prepared.
[0034]
When the amount of the additive is less than 0.1 parts by weight, the effect of uniform wettability is not exhibited. On the other hand, when the amount exceeds 10 parts by weight, the dynamic surface tension is increased and good printability is imparted. It becomes difficult.
[0035]
Therefore, the amount of the additive is preferably 0.1 to 10 parts by weight, particularly 2 to 4 parts by weight.
[0036]
A ceramic green sheet having a thickness of about 20 μm was produced by gravure printing using the ceramic molding composition for evaluation thus obtained. The printing speed was 40 m / min, and a polyester film was used as the carrier film.
[0037]
The surface state of the ceramic green sheet produced according to the above procedure was observed with a stereomicroscope and a scanning electron microscope to evaluate the coatability and smoothness, respectively.
[0038]
Evaluation of coatability is performed by irradiating irradiation light from under the ceramic green sheet with a stereomicroscope, and reading the number of coating film defects such as pinholes per 1 mm ² of the ceramic green sheet at a magnification of 80 times from the opposite side. The case where no defects were observed was evaluated as “◯”, and the case where one or more coating film defects were observed was evaluated as “×”.
[0039]
On the other hand, the smoothness was evaluated by measuring the dimensional accuracy of the film thickness from the fracture surface of the ceramic green sheet with a scanning electron microscope, and the film thickness accuracy of less than 11% ●, 11% to less than 21% A thing was evaluated as ○, and a thing of 21% or more was evaluated as ×.
[0040]
Next, an internal electrode is formed on the ceramic green sheet by a screen printing method, 50 ceramic green sheets are laminated and pressure-bonded, and the pressure-bonded body is debindered at about 400 ° C. in an air atmosphere. Baked at a temperature of about 1300 ° C. for about 2 hours.
[0041]
Subsequently, an external electrode was formed on the fired body to obtain a multilayer ceramic capacitor for evaluation having a 2.00 mm × 1.25 mm square and a capacitance of 1 μF.
[0042]
A DC voltage of 100 V is applied to the evaluation multilayer ceramic capacitor to investigate the number of short-circuit defects, and the number of short-circuit defects is less than 10 out of 300 measurement samples ● 10 or more to less than 16 Were evaluated with ○, and 16 or more were evaluated with ×.
[0043]
As a comparative example, a ceramic green sheet and a multilayer ceramic capacitor produced using the same conditions as in the above example without using an additive and using an ethylene oxide adduct of a fatty acid as an additive were evaluated in the same manner.
[0044]
[Table 1]

[0045]
[Table 2]

[0046]
As is clear from the above results, in Sample No. 1 which does not use an additive, sheet defects such as pinholes are recognized, smoothness is impaired, short-circuit failure occurs, and an ethylene oxide adduct of fatty acid is added. Sample No. 22, which is a product, has good coatability, but has poor smoothness and a short circuit defect.
[0047]
On the other hand, all the results of the present invention have obtained satisfactory results, but especially those containing an acetylene glycol alkyl oxide adduct have good coatability and smoothness, and the number of short-circuit defects. You can see that it is drastically decreasing.
[0048]
In this example, the case where the ceramic molding composition of the present invention was applied to a multilayer ceramic capacitor was described in detail. However, the present invention is not limited to this, and other electronic components such as a ceramic multilayer wiring board are not limited thereto. Is also applicable.
[0049]
【The invention's effect】
As described above, the ceramic molding composition of the present invention contains at least one kind of acetylene alcohol having one triple bond in the molecule, acetylene glycol, and an alkylene oxide adduct of acetylene glycol, and thus has a thickness of 50 μm. The following extremely thin ceramic green sheets have no sheet defects such as pinholes and can be made uniform and have excellent smoothness. When applied to multilayer ceramic capacitors, the occurrence rate of short-circuit defects is greatly increased. Can be reduced to

Claims (1)

A composition obtained by mixing a solvent barium titanate powder and an organic additive used to mold the thin-film ceramic green sheet, acetylene alcohol having one triple bond in the molecular, acetylene glycol or acetylene A ceramic molding composition comprising at least one of alkylene oxide adducts of glycol.