JP2006347808A

JP2006347808A - Functional ceramic

Info

Publication number: JP2006347808A
Application number: JP2005175869A
Authority: JP
Inventors: Toshihiko Akizuki; 俊彦秋月; Eiji Yamaguchi; 英次山口
Original assignee: Nagasaki Prefectural Government
Current assignee: Nagasaki Prefectural Government
Priority date: 2005-06-16
Filing date: 2005-06-16
Publication date: 2006-12-28
Anticipated expiration: 2025-06-16
Also published as: JP4820959B2

Abstract

<P>PROBLEM TO BE SOLVED: To provide an environmental-friendly ceramic product such as a pan and a bowl, wherein oil stain is easily removed with a small amount of detergent and flowing water, and the function is maintained over a long period even under the severe condition of a dish washer. <P>SOLUTION: The functional ceramic is characterized in that fused silica or quartz of microparticles with high purity as industrial waste is uniformly dispersed into a glaze, thus the hardness of the glaze is made high, further, fine ruggedness formed on the surface of the glaze exhibits hydrophilic properties or oil repellency, and oil stain stuck to tableware is easily removed with flowing water. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

本発明は一般家庭や給食用として用いられる、陶磁器製の食器や、建家の外壁やトンネルの内壁などに用いられる陶磁器製のタイルといった陶磁器製品の表面における耐摩耗性、アルカリ洗剤に対する耐食性、親水性と油汚れ除去性など機能の向上と、それら機能を長期にわたり持続させることを可能とした機能性陶磁器に関するものである。 The present invention is used for general households and school lunches, ceramic tableware such as ceramic tableware, ceramic tiles used for building outer walls and tunnel inner walls, etc., wear resistance on the surface of ceramic products, corrosion resistance to alkaline detergents, hydrophilic The present invention relates to functional ceramics capable of improving functions such as the performance of oil and oil stains and maintaining the functions for a long period of time.

陶磁器製の食器やタイルの表層部に、各種アルコキシドやゾルのシリカ原料を塗布し、1000℃以下の加熱によってシリカ膜を作製し、ナノサイズの凹凸を作り出すことで、親水性を付与すると共に、表面硬度を向上させる方法が多数報告されている。（例えば特許文献１、２，３参照）
また、釉薬中にミル粉砕した溶融シリカ、珪砂、長石を添加し、800℃〜1300℃で基材と同時焼成することで、表面の凹凸を低減し、汚れを容易に除去する衛生陶器についても報告されている。（例えば特許文献４、５，６参照）
特開2002−302637号公報特開2002−080830号公報特開2000−211983号公報特開2001−220270号公報特開2001−48681号公報特開2001−48680号公報 Applying various alkoxides and sol silica raw material to the surface layer of ceramic tableware and tiles, creating a silica film by heating at 1000 ° C or lower, creating nano-sized irregularities, giving hydrophilicity, A number of methods for improving surface hardness have been reported. (For example, see Patent Documents 1, 2, and 3)
Also, sanitary ware that reduces surface irregularities and removes dirt easily by adding milled fused silica, silica sand, and feldspar in the glaze and co-firing with the substrate at 800 ° C to 1300 ° C. It has been reported. (For example, see Patent Documents 4, 5, and 6)
JP 2002-302637 A JP 2002-080830 A JP 2000-211983 Japanese Patent Laid-Open No. 2001-220270 JP 2001-48681 A JP 2001-48680 A

しかし、上記従来の技術では、その耐久性や原料コスト並びに製造コストの点で問題が残されていた。まず特許文献１，２，３のような方法は、微細な凹凸が生成することで親水・撥油化し、食器に付着した油分が水洗で容易に落ちやすくなるメリットはあるものの、基材とシリカの接着に用いるアルカリ金属珪酸塩が加熱処理によりシリカと反応し、ガラス化するため、食器用のアルカリ洗剤で溶出し易い。特に、衛生陶器やタイルといった室温程度の水では、その影響は小さいが、一般家庭における手洗いでも４０℃前後の温水、食器洗浄機に至っては８０℃前後の熱水となり、このようなアルカリ洗剤が溶け込んだ温水や熱水中では微細な凹凸は容易に消失してしまう。さらに、食器洗浄機用の洗剤には、こびり付いた汚れを取り除くため、珪酸塩等の研磨剤が入っており、膜厚が薄く、接着強度の低いコーティング材は容易に剥がれてしまうことも問題である。また、原料コストや製造コストに関しても、陶磁器原料に比べ、高価なアルコキシドやゾルを用いることで、原料コストが跳ね上がると共に、製造方法においても1000℃以上で本焼成した製品に、コーティング処理を施し、再度加熱処理を行うことで、加熱の一工程追加が製造コストを上昇させてしまう。
一方、特許文献４，５，６のような方法は、釉薬同士の接着で厚みも厚いことから、耐久性は充分あるものの、特許文献１，２，３のように、微細な表面の凹凸が生成しにくいため、親水・撥油化が充分発現されず、油分の除去が必要でない衛生陶器では有効な方法であるが、食器のように油分の除去を必要とするものには適用できない。さらにこの方法も、原料の高温での溶融加熱処理や冷却後の微粉砕処理が必要であり、製造コストが上昇する。
以上のようなことから、低コストで親水性の超微粒子を釉薬中に均一に分散し、通常の陶磁器と同じ温度で焼成することができれば、上記２つの特許文献のメリットだけを取り入れた、機能とコストと耐久性において優れた陶磁器製品を得ることが可能となる。 However, the conventional techniques described above have problems in terms of durability, raw material costs, and manufacturing costs. First, the methods such as Patent Documents 1, 2, and 3 are made hydrophilic and oil-repellent by forming fine irregularities, and the oil adhering to the tableware has the merit of being easily removed by washing with water, but the substrate and silica Since the alkali metal silicate used for adhesion of the glass reacts with silica by heat treatment and vitrifies, it is easily eluted with an alkaline detergent for tableware. In particular, water at room temperature, such as sanitary ware and tiles, has a small effect, but even hand washing in ordinary homes produces hot water at around 40 ° C, and hot water at around 80 ° C for dishwashers. In the melted warm water or hot water, fine irregularities are easily lost. In addition, detergents for dishwashers contain abrasives such as silicates to remove sticking dirt, and coating materials with thin film thickness and low adhesive strength can easily be peeled off. is there. In addition, with regard to raw material costs and manufacturing costs, by using expensive alkoxides and sols compared to ceramic raw materials, the raw material costs jump, and in the manufacturing method, the products that have been baked at 1000 ° C. or higher are subjected to coating treatment. By performing the heat treatment again, the addition of one step of heating increases the manufacturing cost.
On the other hand, methods such as Patent Documents 4, 5, and 6 have a sufficient thickness due to adhesion between the glazes, so that they have sufficient durability. Since it is difficult to produce, it is an effective method in sanitary ware that does not require hydrophilicity and oil repellency and does not require removal of oil, but cannot be applied to products that require oil removal such as tableware. Furthermore, this method also requires a melt heat treatment at a high temperature of the raw material and a fine pulverization treatment after cooling, resulting in an increase in manufacturing cost.
Because of the above, if low-cost hydrophilic ultrafine particles are uniformly dispersed in the glaze and can be baked at the same temperature as ordinary ceramics, the function incorporating only the merits of the above two patent documents It becomes possible to obtain a ceramic product excellent in cost and durability.

そこで本発明では、低コストで親水性の超微粒子として、シリカ製品を製造する企業から産業廃棄物として廃棄されている、超微粒非晶質溶融シリカあるいは結晶性の石英を釉薬に添加した。しかも、分散剤や焼成後の結合材としてこれまで一般的に用いられていたアルカリ金属珪酸塩を使用しないか最小限に限定し、ポリカルボン酸アンモニウム、ポリメタクリル酸ソーダ、アクリル酸アンモニウム、あるいは炭酸ソーダのうちいずれか１種以上を分散剤として用いることで、超微粒の溶融シリカや石英が均一に分散した状態で、1100℃以上の高温焼成においても高純度で非晶質のまま釉薬中で残存しやすくなる。このように、原料コストが掛からず、加熱処理工程を追加することなく、しかも厚膜の釉薬中に超微粒の溶融シリカや石英が釉薬中に均一に分散し、釉薬表面は微細な凹凸のため、親水・撥油化を示すことが本発明の特徴である。
ここで製造方法に関して、基材となる陶土は、通常の陶磁器製品と同様、食器形状あるいはタイル形状などに成形後、充分乾燥し800℃以上で素焼きを行う。一方、釉薬については、原料の超微粒溶融シリカあるいは石英を、混合する基本となる釉薬の固形分に対し、必要量を容器に秤量し、水と分散剤を加え充分分散させた後、基本となる釉薬と混合する。ここで用いる基本の釉薬は、市販の石灰釉、灰釉、青磁釉などどれでも使用可能である。そして、施釉に関しては、溶融シリカあるいは石英を単独あるいは混合した釉薬を、素焼きした基材に直接施釉してもよいが、釉薬中の溶融シリカや石英量が30%を越えると乾燥収縮や焼成収縮が大きくなり、乾燥や焼成時に亀裂や剥離が発生しやすくなる。そのため、溶融シリカを添加する前の基本となる釉薬を、一旦施釉した後、その上からスプレー等で溶融シリカや石英を添加した釉薬を施釉してやることで、応力が緩和され、亀裂や剥離の発生を防止することができる。それらの方法で施釉した後、通常の陶磁器製品と同様1100℃〜1350℃で焼成を行う。
次に本発明を更に詳しく説明する。 Therefore, in the present invention, ultrafine amorphous fused silica or crystalline quartz, which is discarded as industrial waste from a company that manufactures silica products, is added to the glaze as hydrophilic ultrafine particles at low cost. Moreover, alkali metal silicates that have been generally used as dispersants and binders after firing are not used or limited to a minimum, and ammonium polycarboxylate, polysodium methacrylate, ammonium acrylate, or carbonic acid. By using one or more of soda as a dispersant, ultra-fine fused silica or quartz is uniformly dispersed, and even in high-temperature firing at 1100 ° C or higher, it remains highly pure and amorphous in the glaze. It tends to remain. In this way, raw material costs are not required, no additional heat treatment process is required, and ultra-fine fused silica or quartz is evenly dispersed in the thick film glaze, and the glaze surface has fine irregularities. It is a feature of the present invention that it exhibits hydrophilicity and oil repellency.
Here, regarding the manufacturing method, the ceramic clay used as a base material is formed into a tableware shape or a tile shape in the same manner as a normal ceramic product, and then sufficiently dried and baked at 800 ° C. or higher. On the other hand, for the glaze, we measured the required amount of the raw material ultrafine fused silica or quartz in the container for the solid content of the basic glaze to be mixed. Mix with the glaze. The basic glaze used here can be any commercially available lime cake, ash cake, celadon cake, or the like. With regard to glazing, glazes containing fused silica or quartz alone or mixed may be glazed directly on the unbaked substrate, but if the amount of fused silica or quartz in the glaze exceeds 30%, drying shrinkage or firing shrinkage , And cracks and peeling easily occur during drying and firing. Therefore, once the glaze, which is the basic before adding fused silica, is applied once, then the glaze added with fused silica or quartz is applied by spraying, etc., and the stress is relaxed, and cracks and peeling occur. Can be prevented. After glazing by those methods, firing is performed at 1100 ° C to 1350 ° C in the same manner as ordinary ceramic products.
Next, the present invention will be described in more detail.

これまで説明してきたように、従来の方法では陶磁器製の食器に求められる特性を充分に満たすことはできない。すなわち、アルコキシドやゾルを原料に、釉薬表面にシリカの超微粒子を生成し、その凹凸により親水・撥油化を図る方法は、食器に求められる、油汚れを水洗だけで洗い落とす点に関しては非常に優れているが、その耐久性やコストが大きな問題である。一方、表面の平滑化により汚れの除去を図る方法は、膜厚も厚く耐久性は優れているが、ミルなどによるシリカ粒子の粉砕方法では、ナノサイズまで安価に粉砕する技術には限界があり、そのため特に食器に必要な、微細な凹凸による親水・撥油化が課題である。そこで上記２つのメリットのみを活かした釉薬を開発できれば、従来にない機能性陶磁器を得ることができる。そこで本発明者らは、鋭意研究を重ねた結果、これまでシリカ製品を製造する企業から産業廃棄物として廃棄されていた超微粒子の溶融シリカや石英が有効と考えた。これまでミルによる粉砕では困難なため、アルコキシドやゾルといった溶液から生成されていたナノサイズの微細な粒子が、産業廃棄物として直接得ることができるため、これを釉薬中に混合し、焼成することで微細な凹凸をもつ釉薬表面となり、親水・撥油性を示す。しかも原料コストや製造コストもほとんど掛からない。しかし分散剤に、従来一般的に用いられていたアルカリ金属珪酸塩を用いたものは、食器洗浄機で数回洗浄すると、親水・撥油性が消失した。この原因として、焼成により溶融シリカや石英がアルカリ金属珪酸塩と反応し、アルカリ洗剤に溶出しやすいガラスが生成したためと考えられた。そこで、分散剤にアルカリ金属珪酸塩以外のポリカルボン酸アンモニウム、ポリメタクリル酸ソーダ、アクリル酸アンモニウム、あるいは炭酸ソーダのうちいずれか１種以上を用い、アルカリ珪酸塩を用いないかまたは最小限に限定することで、低融点で耐アルカリ性の低いガラスの生成が抑えられ、食器洗浄機による洗浄でも親水・撥油性が持続し、しかも硬度が高くなることで、食器洗浄機用洗剤に含まれる研磨剤に対する耐久性も向上したものと思われる。
さらに本発明を詳しく説明すると、今回用いた代表的な原料シリカの粒子径は、図1に電子顕微鏡写真を示すように、ナノサイズの超微粒子である。更にその純度であるが、シリカは各種金属酸化物と高温で溶融・反応しやすく、低融点のガラスとなると共に、耐摩耗性や耐アルカリ性が低下する。そのため、釉薬に添加する溶融シリカあるいは石英は純度が高い必要がある。その点、本発明に用いた産業廃棄物の溶融シリカや石英は、もともと純度の高いシリカ製品を製造する工程から排出されたものであるため、問題なくしかも、高温で加熱された原料であるため、熱的にも安定しており、容易に低融点のガラス化を起こさず、釉薬表面に残ることで、親水・撥油性が良好な釉薬となる。更に本発明のもうひとつの特徴には、分散剤にポリカルボン酸アンモニウム、ポリメタクリル酸ソーダ、アクリル酸アンモニウム、あるいは炭酸ソーダのうちいずれか１種以上を用い、アルカリ金属珪酸塩を用いないかまたは最小限に限定した点にある。これは、従来一般的に分散材やバインダーとして用いられていたアルカリ金属珪酸塩は、シリカ粒子と反応性が高く、焼結により低融点のガラスを生成しやすい。そのため、食器やタイルといったアルカリ洗剤で洗浄を行う製品は、表面の凹凸が溶出し易く、その機能を失いやすい。それに比べ本発明に用いる分散剤は、超微粒子であるシリカや石英粒子の分散には充分その作用を示し、しかも焼成によって、シリカや石英と反応を起こしにくいことで、洗浄を行っても親水・撥油性が持続する。また今回、機能を持つ釉薬厚みが数十μm以上と厚いため、たとえ洗剤によりシリカや石英微粒子周囲が溶出しても、さらにその下部にあるシリカや石英微粒子が表面となり、微細な凹凸となることで、親水・撥油性が長期にわたり持続する結果となる。しかも、本発明は親水・撥油性を示すことで、従来陶磁器製品よりも、かなり洗剤量を減らしても汚れ落ちが良好で、少ない油汚れ程度なら、洗剤なしの流水のみでも洗浄可能である。そのため、アルカリ洗剤濃度が低下することで、親水・撥油性は半永久的に持続可能となる。次にその溶融シリカや石英の釉薬への添加量であるが、釉薬固形分濃度で30%以下では、素焼した基材に直接施釉しても問題ないが、30%を越えると乾燥収縮や焼成収縮が大きくなり、亀裂や剥離を起こしやすくなる。そのため、一旦溶融シリカや石英を添加する前の基本となる釉薬を施釉し、その上から溶融シリカや石英を添加した釉薬をコーティングすることで、応力が緩和され、亀裂や剥離が抑制される。 As explained so far, the conventional methods cannot sufficiently satisfy the characteristics required for ceramic tableware. In other words, using alkoxide or sol as a raw material, ultrafine particles of silica are formed on the surface of the glaze, and the method to achieve hydrophilicity and oil repellency by the unevenness is very important in terms of washing off oil stains only with water washing required for tableware. It is excellent, but its durability and cost are big problems. On the other hand, the method of removing dirt by smoothing the surface has a large film thickness and excellent durability, but the silica particle pulverization method using a mill or the like has a limit to the technology for pulverizing to nano size at low cost. Therefore, hydrophilicity and oil repellency by the fine unevenness necessary for tableware is a problem. Therefore, if a glaze utilizing only the above two merits can be developed, an unprecedented functional ceramic can be obtained. Thus, as a result of intensive studies, the present inventors have considered that fused silica and quartz of ultrafine particles, which have been discarded as industrial waste by companies that manufacture silica products so far, are effective. Since it is difficult to pulverize with a mill so far, nano-sized fine particles generated from solutions such as alkoxides and sols can be obtained directly as industrial waste. It becomes a glaze surface with fine irregularities and shows hydrophilic and oil repellency. Moreover, there is almost no raw material cost or manufacturing cost. However, when the alkali metal silicate that has been generally used as a dispersant is washed several times with a dishwasher, the hydrophilicity and oil repellency disappeared. This was thought to be due to the fact that fused silica or quartz reacted with the alkali metal silicate by firing to produce a glass that easily eluted into the alkaline detergent. Therefore, any one or more of ammonium polycarboxylate other than alkali metal silicate, sodium polymethacrylate, ammonium acrylate, or sodium carbonate is used as the dispersant, and alkali silicate is not used or limited to the minimum. As a result, the generation of glass with low melting point and low alkali resistance is suppressed, the hydrophilic and oil repellency is maintained even when washing with a dishwasher, and the hardness is increased, so that the abrasive contained in the dishwasher detergent It is thought that the durability against ash was also improved.
Further explaining the present invention in detail, the particle diameter of the typical raw material silica used this time is nano-sized ultrafine particles as shown in the electron micrograph in FIG. Further, although it is pure, silica easily melts and reacts with various metal oxides at a high temperature, becomes a glass having a low melting point, and wear resistance and alkali resistance are lowered. Therefore, the fused silica or quartz added to the glaze needs to have high purity. In that respect, the fused silica and quartz of industrial waste used in the present invention were originally discharged from the process of producing a high-purity silica product, and therefore are raw materials heated at a high temperature without any problems. It is also thermally stable, does not easily cause low melting point vitrification, and remains on the surface of the glaze, so that the glaze has good hydrophilicity and oil repellency. Still another feature of the present invention is that any one or more of ammonium polycarboxylate, sodium polymethacrylate, ammonium acrylate, or sodium carbonate is used as the dispersant, and no alkali metal silicate is used. It is limited to the minimum. This is because alkali metal silicates that have been generally used as a dispersing agent or binder in the past are highly reactive with silica particles, and are likely to produce a glass having a low melting point by sintering. For this reason, products that are washed with an alkaline detergent such as tableware and tiles are likely to have surface irregularities that are easily eluted and lose their function. On the other hand, the dispersant used in the present invention is sufficiently effective for dispersing silica and quartz particles, which are ultrafine particles, and is difficult to cause a reaction with silica and quartz by firing. Oil repellency lasts. In addition, since the thickness of the glaze with the function is as thick as several tens of μm or more this time, even if the silica and quartz fine particles are eluted by the detergent, the silica and quartz fine particles below it become the surface and become fine irregularities. As a result, hydrophilicity and oil repellency are maintained over a long period of time. In addition, the present invention exhibits hydrophilicity and oil repellency, so that the removal of dirt is better than conventional ceramic products even if the amount of detergent is considerably reduced, and if the degree of oil stain is small, it can be washed only with running water without detergent. Therefore, hydrophilicity and oil repellency can be maintained semipermanently by decreasing the concentration of the alkaline detergent. Next, the amount of fused silica or quartz added to the glaze is 30% or less in the case of a glaze solid content concentration. Shrinkage is increased and cracking and peeling are likely to occur. Therefore, by applying a glaze, which is a basic before adding fused silica or quartz, and coating a glaze to which fused silica or quartz is added, the stress is relaxed and cracks and peeling are suppressed.

本発明において、基本となる釉薬は市販の石灰釉や灰釉、青磁釉、タルク釉など、食器やタイル用として一般的に用いられている釉薬に利用できる。あるいは必要とする釉式に基づいて長石、陶石、カオリン、石灰石、珪石などを配合し、目的とする釉薬を作製する。その時、珪石の一部を超微粒子の溶融シリカや石英で置き換えることも可能である。これら基本となる釉薬について、まずその固形分濃度を測定する。測定はあらかじめ充分乾燥し、重量を測定しておいたシャーレに釉薬を流し込み、重量を測定する。その後、乾燥機中105℃で充分乾燥の後、デシケーター中で室温まで冷却し、重量を測定することで、固形分濃度を算出する。次にその固形分濃度に対し、目的の濃度になるよう、原料の溶融シリカや石英を秤量し、ビーカーに移し、水と分散材を加えて充分撹拌し分散させる。その後、基本となる釉薬とシリカ溶液を混合し、充分撹拌する。次いで、あらかじめ成形後、乾燥、800℃以上で素焼きしておいた陶磁器製基材に直接施釉する。このとき、シリカ添加量が30%を超えると、乾燥収縮や焼成収縮が大きくなり、亀裂や基材からの剥離が生じ易くなるため、前もってシリカを含まない基本となる釉薬のみで施釉を行っておき、その上からスプレーコート、フローコート等の周知の方法でシリカを含んだ釉薬を施すことで、亀裂や剥離を防止できる。その後、両方法とも1100℃〜1350℃で焼成することにより、釉薬表面に微細な凹凸が生成し、親水・撥油性を有する高硬度な釉薬を持つ陶磁器製品となる。
本発明の実施例と比較例を以下に詳しく説明する。 In the present invention, the basic glaze can be used for glazes generally used for tableware and tiles, such as commercially available lime glaze, ash glaze, celadon porcelain, and talc glaze. Alternatively, feldspar, porcelain stone, kaolin, limestone, silica stone, etc. are blended based on the required dredging formula to produce the desired glaze. At that time, it is possible to replace a part of the silica with ultrafine fused silica or quartz. About these basic glazes, the solid content concentration is first measured. The measurement is sufficiently dried in advance, and the glaze is poured into a petri dish that has been weighed, and the weight is measured. Then, after sufficiently drying at 105 ° C. in a dryer, the solid content concentration is calculated by cooling to room temperature in a desiccator and measuring the weight. Next, the raw material fused silica or quartz is weighed so as to have a target concentration with respect to the solid content concentration, transferred to a beaker, and water and a dispersing agent are added and sufficiently stirred and dispersed. Thereafter, the basic glaze and the silica solution are mixed and sufficiently stirred. Next, it is directly glazed on a ceramic base material that has been previously molded, dried and baked at 800 ° C. or higher. At this time, if the amount of silica added exceeds 30%, drying shrinkage and firing shrinkage increase, and cracks and peeling from the base material are likely to occur, so that only the basic glaze not containing silica is applied in advance. In addition, by applying a glaze containing silica by a known method such as spray coating or flow coating, cracking and peeling can be prevented. Thereafter, both methods are baked at 1100 ° C. to 1350 ° C. to produce fine irregularities on the surface of the glaze, resulting in a ceramic product having a high-hardness glaze having hydrophilic and oil repellency.
Examples of the present invention and comparative examples will be described in detail below.

市販の石灰釉を基本とする釉薬とし、それに対し平均粒径150ｎｍの溶融シリカの固形分濃度を変化させ、基材となるφ160ｍｍの磁器製の素焼き皿に直接施釉した。この時分散剤にはポリメタクリル酸ソーダを溶融シリカに対し0.3%添加した。その結果、溶融シリカ添加量が0%から30%までは施釉時や、その後の1280℃での焼成においても問題なく焼結体が得られた。しかし、溶融シリカ添加量30%を越えると、施釉時に剥離が生じ施釉不可能であった。そこで、30%を越える溶融シリカ添加量のものについては一旦、溶融シリカを含まない基本とする釉薬のみで施釉しておき、その上からスプレーコーティングを行ったところ、施釉時、焼成時に亀裂や剥離の発生もなく、良好な結果であった。 A glaze based on a commercially available lime cake was used, and the solid content concentration of fused silica having an average particle size of 150 nm was changed, and the glaze was directly applied to a porcelain unglazed dish of φ160 mm as a base material. At this time, 0.3% of sodium polymethacrylate was added to the dispersing agent with respect to the fused silica. As a result, when the addition amount of fused silica was from 0% to 30%, a sintered body was obtained without any problem even during glazing or subsequent firing at 1280 ° C. However, when the added amount of fused silica exceeded 30%, peeling occurred during glazing, and glazing was impossible. Therefore, when the amount of fused silica added exceeds 30%, once it was glazed only with a basic glaze that does not contain fused silica, and then spray coating was performed, cracks and delamination occurred during glazing and firing. The result was good without any occurrence.

実施例１の配合のものについて、5cm角の陶板試料に片面施釉を行い、ビッカース硬度計による釉薬硬度の測定と、落砂式耐摩耗試験（JIS-A-5209）を行った。その結果はそれぞれ図２と図３に示す通り、溶融シリカの添加量により釉薬硬度は向上し、研磨剤に対する耐摩耗性も向上する結果となった。 About the thing of the mixing | blending of Example 1, the single-sided glazing was performed to the 5 cm square ceramic board sample, the glaze hardness measurement with the Vickers hardness tester, and the sandfall-type abrasion resistance test (JIS-A-5209) were done. As a result, as shown in FIGS. 2 and 3, the glaze hardness was improved by the addition amount of the fused silica, and the abrasion resistance against the abrasive was also improved.

（比較例１）
市販の青磁釉を基本とする釉薬とし、それに対し平均粒径150ｎｍの溶融シリカ10%と平均粒径300ｎｍの石英10%を添加・混合した。この時分散剤に、ポリメタクリル酸ソーダを0.3%添加したものと、珪酸ソーダを同じく0.3%添加したものを２種類作製し、それぞれ5cm角の素焼き陶板に施釉し、1260℃で焼成を行った。焼成後の試料を一般家庭の食器洗浄機に入れ、洗剤を投入の後、標準コースで洗浄処理を２回行った。それぞれの試料について、洗浄前後での釉薬表面の水との接触角を測定したところ、図４のように珪酸ソーダを用いたものは、洗浄処理により接触角が大きくなり、親水性が大幅に低下していた。 (Comparative Example 1)
A glaze based on commercially available celadon porcelain was used, and 10% fused silica with an average particle size of 150 nm and 10% quartz with an average particle size of 300 nm were added and mixed. At this time, two kinds of dispersants, 0.3% polymethacrylic acid soda and 0.3% sodium silicate added in the same manner, were applied to 5cm square unglazed ceramic plates and fired at 1260 ° C. . The sample after baking was put into the dishwasher of a general household, and after washing | cleaning was thrown in, the washing process was performed twice in the standard course. For each sample, the contact angle with water on the surface of the glaze before and after washing was measured. As shown in FIG. 4, those using sodium silicate increased in contact angle due to washing treatment, and the hydrophilicity was greatly reduced. Was.

（比較例２）
市販の石灰釉を基本とする釉薬とし、これに溶融シリカを10%添加する。ここで用いる溶融シリカは、平均粒径150ｎｍと、市販の粒度の粗いものをボールミルにより粉砕した平均粒径3.5μｍの２種類準備し、各々10cm角の陶磁器の素焼きした陶板に施釉した。その後、1280℃で焼成し、得られた試験板について触針式表面粗さ測定器で、中心線表面粗さ（Ra）を測定した結果、平均粒径150nmの溶融シリカを用いたものは、Ra=0.030μm、一方平均粒径3.5μmのものはRa=0.150μmとなり、超微粒子の溶融シリカを用いたものが微細な凹凸を示した。さらに撥油性を調べるために、水中での油の接触角を測定したところ、平均粒径150nmの溶融シリカを用いたものが120°であるのに対し、平均粒径3.5μmの溶融シリカを用いたものは100°となり、超微粒子の溶融シリカを用いたものが良好な撥油性を示した。 (Comparative Example 2)
A glaze based on commercially available lime cake is used, and 10% of fused silica is added thereto. As the fused silica used here, two kinds of particles having an average particle diameter of 150 nm and an average particle diameter of 3.5 μm obtained by pulverizing commercially available coarse particles with a ball mill were prepared, and each was applied to an unglazed ceramic plate of 10 cm square ceramic. Then, as a result of measuring the center line surface roughness (Ra) with a stylus type surface roughness measuring instrument for the obtained test plate with 1280 ° C., those using fused silica with an average particle size of 150 nm Ra = 0.030 μm and mean particle size 3.5 μm Ra = 0.150 μm, and those using ultrafine fused silica showed fine irregularities. Further, in order to investigate the oil repellency, the contact angle of oil in water was measured and it was 120 ° using fused silica with an average particle size of 150 nm, whereas fused silica with an average particle size of 3.5 μm was used. The result was 100 °, and the one using ultrafine fused silica showed good oil repellency.

原料の超微粒溶融シリカの電子顕微鏡写真。Electron micrograph of raw ultrafine fused silica. 釉薬への超微粒溶融シリカ添加量とビッカース硬度測定値との関係である。It is the relationship between the amount of ultrafine fused silica added to the glaze and the measured value of Vickers hardness. 釉薬への超微粒溶融シリカ添加量と落砂式耐摩耗試験測定値との関係である。It is the relationship between the amount of ultrafine fused silica added to the glaze and the measured value of the falling sand type abrasion resistance test. 食器洗浄機で洗浄前後における釉薬表面の水との接触角測定値である。It is a contact angle measurement value with the water of the glaze surface before and behind washing with a dishwasher.

Claims

In ceramics that have been glazed on a base material that has been pre-fired from porcelain clay, it is an ultrafine industrial waste, amorphous fused silica or crystals that is discharged in the glaze during the production process of silica products. Functional ceramics with enhanced hydrophilicity and oil repellency, characterized by adding at least one of the functional quartz and firing at 1100 ° C to 1350 ° C.

It is an ultrafine industrial waste that is discharged from the silica product manufacturing process by applying glaze on the base material made by calcining porcelain clay, and it is made of amorphous fused silica or crystalline quartz. The functional ceramic according to claim 1, wherein the ceramic is fired at 1100 ° C. to 1350 ° C. after the glaze added with at least one of them is applied.

In order to disperse the fused silica and quartz used in claims 1 and 2 in the glaze, at least one of ammonium polycarboxylate, polysodium methacrylate, ammonium acrylate, and sodium carbonate is used, and an alkali is used. The functional ceramic according to claim 1 or 2, characterized in that a metal silicate is not used or limited to a minimum.

The functional ceramic according to claim 1 or 2, wherein the fused silica and quartz used in claim 1 and claim 2 are ultrafine particles having an average particle diameter of 3000 nm or less.