JP2004043924A - Metal of excellent photocatalytic activity, and method for manufacturing the same - Google Patents
Metal of excellent photocatalytic activity, and method for manufacturing the same Download PDFInfo
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- JP2004043924A JP2004043924A JP2002205358A JP2002205358A JP2004043924A JP 2004043924 A JP2004043924 A JP 2004043924A JP 2002205358 A JP2002205358 A JP 2002205358A JP 2002205358 A JP2002205358 A JP 2002205358A JP 2004043924 A JP2004043924 A JP 2004043924A
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- 230000001699 photocatalysis Effects 0.000 title claims abstract description 34
- 229910052751 metal Inorganic materials 0.000 title claims abstract description 9
- 239000002184 metal Substances 0.000 title claims abstract description 9
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- 238000000034 method Methods 0.000 title description 12
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 claims abstract description 60
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 claims abstract description 58
- 239000010445 mica Substances 0.000 claims abstract description 35
- 229910052618 mica group Inorganic materials 0.000 claims abstract description 35
- RJDOZRNNYVAULJ-UHFFFAOYSA-L [O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[F-].[F-].[Mg++].[Mg++].[Mg++].[Al+3].[Si+4].[Si+4].[Si+4].[K+] Chemical compound [O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[O--].[F-].[F-].[Mg++].[Mg++].[Mg++].[Al+3].[Si+4].[Si+4].[Si+4].[K+] RJDOZRNNYVAULJ-UHFFFAOYSA-L 0.000 claims abstract description 14
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- MCMNRKCIXSYSNV-UHFFFAOYSA-N Zirconium dioxide Chemical compound O=[Zr]=O MCMNRKCIXSYSNV-UHFFFAOYSA-N 0.000 description 4
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- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 2
- 238000000354 decomposition reaction Methods 0.000 description 2
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- LCKIEQZJEYYRIY-UHFFFAOYSA-N Titanium ion Chemical compound [Ti+4] LCKIEQZJEYYRIY-UHFFFAOYSA-N 0.000 description 1
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- SOQBVABWOPYFQZ-UHFFFAOYSA-N oxygen(2-);titanium(4+) Chemical class [O-2].[O-2].[Ti+4] SOQBVABWOPYFQZ-UHFFFAOYSA-N 0.000 description 1
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Abstract
Description
【０００１】
【産業上の利用分野】
本発明は、長期にわたって光触媒活性を維持し、抗菌性，耐汚染性および耐指紋性に優れた金属材料とその製造方法に関する。
【０００２】
【従来の技術】
アナターゼ型の酸化チタンに、そのバンドギャップ以上のエネルギ−を有する波長の光を照射した場合、光励起により伝導帯に電子が、価電子帯に正孔が生じ、生じた正孔は強い酸化力を有するので、酸化チタン表面に接触した有機物はその酸化還元作用によって分解される。このような光触媒作用を利用して、酸化チタンを、防汚，抗菌，脱臭，ＮＯｘ・ＳＯｘ分解等、種々の環境対策に応用しようとしている。すなわち、酸化チタンを含む皮膜をガラス，プラスチックス，金属等の基体表面に形成し、防汚，抗菌，脱臭，ＮＯｘ・ＳＯｘ分解等に活用しようとするものである。
優れた光触媒活性を発揮させるためには、酸化チタンは表面積を大きくした状態で使用されることが好ましい。このため、一般的にはバインダ成分中に微細粉末形状で分散され、バインダ成分とともに基体表面に薄膜状に被覆して光触媒層を形成して使用されている。そして、光触媒作用を十分に発揮し、しかも光触媒層自身の密着性や耐久性を高めるために、バインダ成分の選択を含め、光触媒層の形成方法に関して各種検討が進められている。
【０００３】
【発明が解決しようとする課題】
基体表面に光触媒層を形成するには、酸化チタン微粒子を含む樹脂塗料組成物を浸漬やスプレー等の方法で塗装し、焼付け乾燥して成膜する方法が最も簡便である。しかしながら、樹脂塗膜は硬さや加工性が十分でなく、塗装金属材料の加工時にクラックが発生したり、疵が付きやすい他、接着力も低いため塗膜が剥がれやすい。さらに、光触媒層の酸化還元作用により塗膜樹脂自体が化学変化して、塗膜が変色，劣化するという問題もある。
そこで、有機物に代わって無機物質をバインダ成分に使用しようとする検討も行われている。
【０００４】
基板表面に酸化チタンをＣＶＤ法で蒸着させたり、プラズマ溶射を行う方法が特開平６−２１０１７０号公報で提案されているが、いずれの方法も製造コストが非常に高くなる。
また、特開平９−３０１７４２号公報では、光触媒機能と耐指紋性機能を得ることを目的として、チタンを含む金属酸化物ゾルが鎖状でコロイダルシリカを含む複合溶液を塗布し、焼成することにより、皮膜を形成する方法が、さらに特開平２−５０１５４号公報では、多孔性ガラスにチタン（ＩＶ）テトラブトキシオキサイドのアルコール溶液を含浸し、加熱してアナターゼ型の酸化チタンを固定する方法が提案されている。しかしながら、これらの方法でも塗布する溶液の粘度や塗布条件によって形成される皮膜に厚みが変化し易いばかりでなく、基板から剥離し易い等の問題がある。さらにまた、特開平１０−１８０８２号公報では、金属材料を陽極体としてチタン酸およびペルオキソチタン酸等のコロイド溶液を通電し、チタン化合物含有皮膜を形成し、この皮膜を乾燥、焼成することにより酸化チタンの皮膜を形成する方法が提案されている。しかし、これらの方法による皮膜は粉末状での形態ではなく、バルク状態であるため、粉末のまま酸化チタンを固定したものよりも表面積が小さくなり、光触媒機能は相対的に低い。
【０００５】
特開平１０−１９８２７４号公報には、ステンレス鋼板上に設けた釉薬層中に酸化チタン微粒子を固着することにより、汚染防止を図ったステンレス表示板が記載されている。この技術においても、光触媒機能を期待する酸化チタン微粒子は緻密なガラス釉薬層で完全に被覆されて固定化されているので、水あるいは大気は釉薬層中の酸化チタン表面に達せず、含有している酸化チタンの光触媒機能を十分に発揮できていない。
【０００６】
ところで、金属材料を環境衛生上問題になるトイレ，洗面所あるいは食品衛生工場の天井，壁，床等のパネルなどに適用しようとすると、抗菌性，耐汚染性，脱臭性，有機物分解性，親水性，防汚性，耐指紋性等を有する光触媒機能をもつことが要求される。
上記した皮膜の形成方法では、バルク状態の皮膜が形成されるか、酸化チタン微粒子が緻密なバインダー層，釉薬層で被覆されて固定化されているために、最表面に露出した酸化チタンのみしか光触媒機能を発現できていない。固定化している膜状物質が酸化チタンの表面反応を阻害しているためである。
脱臭性，有機物分解機能は、極めて高い光触媒機能を必要とし、できるだけ高い表面積を得ることを必要としているので、酸化チタン微粒子を粉体の状態で、しかも表面を露出した状態で存在させることが望まれる。
【０００７】
本発明は、このような問題を解消すべく案出されたものであり、金属材料表面に、露出表面積を広くした態様で酸化チタン微粒子を含有する無機系皮膜を形成して、光触媒機能の他に各種機能を発現できる金属材料を提供することを目的とする。
【０００８】
【課題を解決するための手段】
本発明の光触媒活性に優れた金属材料は、その目的を達成するため、酸化チタン微粒子が分散された雲母層が金属基板の表面に形成されていることを特徴とする。
また、その光触媒活性に優れた金属材料は、０．５質量％以上の酸化チタン微粉末を合成雲母に添加混合した混合粉末を投射材として金属材料表面にブラスト処理を施すことにより得られる。
使用する酸化チタン粉末としては平均粒径１．０μｍ以下のものを、合成雲母としては長径が２０〜３０μｍのものを使用することが好ましい。
雲母層を形成した後、さらにブラスト処理を施して、前記雲母層を緻密化することが好ましい。
【０００９】
【作用】
本発明者等は、光触媒機能を有する酸化チタン微粉末を、金属材料表面に無機質材料で固定するために、バインダ成分になる無機材料とその皮膜形成手段について、種々検討を続けてきた。
その結果、合成雲母をブラスト法で吹き付けると、雲母は砕かれ、金属材料表面で互いの衝突エネルギーで半溶融状態となって強固に金属材料表面に固着されることが確認された。
この際、予め合成雲母中に微細な酸化チタン粉末が十分に攪拌・混合されていると、電気絶縁性の高い雲母の静電引力により表面に酸化チタンが付着された雲母が得られる。そして、この混合粉を投射材としてブラストすると、酸化チタン微粉末は雲母表面に付着されたまま金属材料表面に投射され、金属材料表面に付着された雲母中に抱き込まれた状態で保持され、金属材料表面に固定されることになる。
【００１０】
表面の皮膜構造を図１に基づいて説明する。
全体に微細なポーラス態様を示している。雲母は硬度が低い（モース硬度：３．４）ために、ブラスト処理により容易に燐片形状がくずれ、その状態で堆積されてポーラスな形態を示している。ブラスト時、雲母に付着していた酸化チタン微粒子はそのまま内部に取り込まれた状態になっている。このため、表面水および大気がポーラスな構造の内部にも入り込め酸化チタン表面に容易に到達できるので、内部に存在する酸化チタンも光触媒機能を発現できている。すなわち、バルク状態あるいは緻密な結合層による固着状態よりも実質的な表面積が大きくなっているために、優れた光触媒機能を発現できている。さらに、最表面も凹凸形状を有しており、表面積の増大に寄与している。
【００１１】
酸化チタン微粒子が、金属材料表面にポーラスな雲母層に取り込まれた形態で固定されているために、十分な光触媒機能が発揮できていると推測される。また、光触媒機能をもつ酸化チタン微粒子が無機質の合成雲母成分で固着された形態となっているので、極めて良好な親水性を有している。
本発明により形成された皮膜は、金属材料表面に合成雲母がブラストによる衝突エネルギーで半溶融状態となって強固に固着しているため、塗膜等のバインダ成分を利用した場合に比べ、密着性，曲げ性が高い傾向にある。また、光の乱反射が抑制される微細凹凸を有する無機質皮膜表面であるため指紋が目立ち難く、光触媒機能も高いため付着した指紋も速やかに分解されて消失しやすい。すなわち、耐指紋性も高い。さらに、光触媒活性が高いことに付随して防汚性も高くなると考えられる。
【００１２】
なお、単にブラストして合成雲母を主体とした皮膜を形成しても、当該皮膜は、ポーラスであるために、耐候性（耐水性）の点で十分ではない。そのため、耐水性等が要求される部材へ適用する場合には、合成雲母を主体とした皮膜を形成した後、ガラスビーズ等を用いてブラスト処理すると、皮膜の密度が高められ、粗い表面の凹凸も緻密・微細な凹凸に変化するため、耐候性，密着強度も向上する。
【００１３】
【実施の態様】
本発明の酸化チタン微粒子分散雲母層を被着させる金属材料は、特に制限されない。冷延炭素鋼板，ステンレス鋼板，アルミニウム合金板等が使用できる。
ブラスト処理により酸化チタン微粒子分散雲母層を被着させる金属材料には、基本的には特別な前処理を施す必要はないが、表面に疵，汚れあるいはスケール等が存在している場合には、アルミナ等の硬質な研掃材を用いて除去しておくことが好ましい。
【００１４】
投射材の主たる成分である雲母の種類には、特に制限はない。用途に応じた意匠性を考慮して所望の色調の雲母を選択しても良い。また、雲母の粒径も酸化チタンが雲母とともにブラスト処理可能で、成膜が形成できるだけの運動エネルギーをもつことができる粒径であれば十分である。
使用する酸化チタンとしては、ルチル型，アナターゼ型のいずれのものも使用可能であるが、優れた光触媒機能を得るためにはアナターゼ型の酸化チタンを使用することが好ましい。光触媒活性を高めるためには、より細かい粒径の酸化チタンを使用することが好ましい。１．０μｍ以下のものを使用することが望ましい。
また、投射材における配合割合については、雲母と酸化チタンの体積比でほぼ５：１が混合下限界であり、その割合から０．５質量％以上の混合が可能である。雲母層に効率的に固定され、優れた光触媒機能を発揮させるためには、１〜３０質量％の割合で雲母と混合しておくことが好ましい。
【００１５】
ブラスト処理後の皮膜中成分の均一化を図るためには、この投射材の雲母と酸化チタンを均一に混合しておく必要がある。雲母を粉砕しないように、かつ雲母に静電気を発生させて酸化チタン微粒子を付着させる必要がある。このためには、合成樹脂製の容器に各粉体を投入し、アルミナやジルコニア等のボールを同時に投入して容器自体を回転させて混合する形式を採ることが好ましい。
ブラスト処理に使用する装置としては、空気式加速装置，機械式加速装置等のいずれの方式のものも使用可能である。処理膜の密着性や投射効率を考慮すると、より高い投射速度が得られる直圧式の空気式加速装置を用いることが好ましい。
【００１６】
合成雲母を主体とした皮膜を形成した後、皮膜を緻密化するためにガラスビーズ等でブラスト処理する際、使用するブラスト材としては一般的な材質のソーダガラスで十分である。またその形状も球状のものを使用することが好ましい。表面の緻密化との関係においては、粒径が０．１ｍｍ程度のものを使用することが好ましい。
また、投射圧力は、研削作用が発現しない範囲の０．１ＭＰａ程度を実施することが好ましい。
【００１７】
【実施例】
実施例１ ：
長径３０μｍの合成雲母（トピー工業社製、ＰＤＭ−７−８０）９０質量％と粒径０．０５μｍ以下の酸化チタン粉末（日本エアロジル社製、Ｐ２５）１０質量％を秤量し、自作の混合装置に、粉体体積に対して約３０％を占めるように直径１０ｍｍのジルコニアボールを適正数入れ、５分程度混合攪拌して投射材を調製した。
被投射材としてＳＵＳ３０４鋼板のＢＡ仕上げ材を用い、直径１０ｍｍの噴射ノズルを有する直圧式ブラスト装置を使用して０．３ＭＰａの空気圧で約５分程度ブラスト処理して、表面に付着層を有するステンレス鋼板を得た。
ブラスト処理後、処理面をＥＰＭＡで元素分析して、表面にＳｉ，ＡｌおよびＯの他にＴｉが存在することを確認した。
この被覆金属材料について各種特性を調査した。
なお比較材として、同じステンレス鋼板のＢＡ材を用いた。
各特性の評価手法、評価基準は表１に示す通りである。
表１中、「ＣＣＴ」と表記した塩乾湿複合サイクル試験は、塩水噴霧（５％ＮａＣｌ，１０分）→乾燥（６０℃，３０％ＲＨ，６０分）→湿潤（５０℃，９５％ＲＨ，１８０分）を１サイクルとするものである。
【００１８】
実施例２
実施例１で使用した合成雲母，酸化チタン粉末，混合条件，ステンレス鋼板，ブラスト条件を用い、酸化チタン粉末の混合割合のみを、０，０．５，１，５，１０，２０，２５，３０，４０，５０，９９質量％に変えて、合成雲母層を形成した。
そして、実施例１と同じ手法で各種特性について調査した。
その結果を表２に示す。
【００２１】
実施例３：
実施例１により製造した酸化チタン分散雲母層を形成した鋼板に、さらに、平均粒径１００μｍの球形ガラスビーズを噴射圧力０．１ＭＰａでブラスト処理した。この条件は、研削作用を抑え、押し付け力を付与することが可能な範囲で設定したものである。
後処理した処理鋼板の特性を、実施例１と同じ手法で調査した。
その結果を表４に示す。
この表に示す４項目の特性は、ガラスビーズブラスト処理することにより、大きく向上していた。その他の特性については、ガラスビーズブラスト処理の施していないものとほぼ同等の特性を示し、特性の低下は認められなかった。
【００２３】
【発明の効果】
以上に説明したように、光触媒活性に優れた酸化チタン微粒子を雲母とともに金属材料表面にブラスト処理すると、金属材料表面に酸化チタン微粒子が分散されたポーラスな雲母層が形成されるため、大気や水と接触する酸化チタン微粒子の表面積を大きくして光触媒機能を最大限利用することができる。
また、酸化チタンを固定している雲母層はブラスト処理により金属材料に半溶融状態で固着されているので付着強度が高いため、密着強度が高く、加工性にも優れている。しかも層形成手段に由来した微細凹凸を有しているため、親水性や耐指紋性を有する等、本来の光触媒機能とそれに付随した多機能を有しているので、光触媒機能付加金属材料の用途を大幅に拡大することが可能になる。
【図面の簡単な説明】
【図１】酸化チタン分散雲母層を形成した金属材料表面の断面構造を模式的に説明する図[0001]
[Industrial applications]
The present invention relates to a metal material which maintains photocatalytic activity for a long period of time and has excellent antibacterial properties, stain resistance and fingerprint resistance, and a method for producing the same.
[0002]
[Prior art]
When anatase-type titanium oxide is irradiated with light having a wavelength having energy equal to or greater than its band gap, electrons are generated in the conduction band and holes are generated in the valence band by photoexcitation, and the generated holes have strong oxidizing power. As a result, organic substances that have come into contact with the titanium oxide surface are decomposed by the redox action. Utilizing such photocatalysis, titanium oxide is being applied to various environmental measures such as antifouling, antibacterial, deodorizing, and decomposition of NOx / SOx. That is, a film containing titanium oxide is formed on the surface of a substrate such as glass, plastics, and metal, and is used for antifouling, antibacterial, deodorizing, and decomposition of NOx / SOx.
In order to exhibit excellent photocatalytic activity, titanium oxide is preferably used in a state where the surface area is large. For this reason, the photocatalyst layer is generally used by being dispersed in the form of fine powder in the binder component and coating the substrate surface with the binder component in a thin film form. In order to sufficiently exert the photocatalytic action and to enhance the adhesion and durability of the photocatalyst layer itself, various studies have been made on a method for forming the photocatalyst layer, including selection of a binder component.
[0003]
[Problems to be solved by the invention]
In order to form a photocatalyst layer on the surface of the substrate, the simplest method is to apply a resin coating composition containing titanium oxide fine particles by a method such as dipping or spraying, and bake and dry to form a film. However, the resin coating film does not have sufficient hardness and workability, and cracks and scratches easily occur during processing of the coated metal material, and the coating film is easily peeled off due to low adhesive strength. Further, there is also a problem that the coating resin itself is chemically changed by the oxidation-reduction action of the photocatalyst layer, and the coating is discolored and deteriorated.
Therefore, studies have been made to use an inorganic substance as a binder component instead of an organic substance.
[0004]
Japanese Patent Application Laid-Open No. 6-210170 proposes a method of depositing titanium oxide on a substrate surface by a CVD method or performing plasma spraying. However, any of these methods has a very high manufacturing cost.
Further, in Japanese Patent Application Laid-Open No. 9-301742, in order to obtain a photocatalytic function and a fingerprint resistance function, a metal oxide sol containing titanium is coated with a complex solution containing colloidal silica in the form of a chain, followed by firing. Japanese Patent Laid-Open No. 50154/1990 proposes a method of impregnating porous glass with an alcohol solution of titanium (IV) tetrabutoxy oxide and heating the glass to fix anatase-type titanium oxide. Have been. However, even with these methods, there are problems that the thickness of the film formed easily varies depending on the viscosity of the solution to be applied and the application conditions, and that the film easily peels off from the substrate. Further, in Japanese Patent Application Laid-Open No. 10-18082, a metal compound is used as an anode body, a colloidal solution such as titanic acid and peroxotitanic acid is supplied with electricity to form a titanium compound-containing film, and the film is dried and fired to oxidize. A method for forming a titanium film has been proposed. However, since the film formed by these methods is not in the form of a powder but in a bulk state, the surface area is smaller than that in which titanium oxide is fixed as a powder, and the photocatalytic function is relatively low.
[0005]
Japanese Patent Application Laid-Open No. 10-198274 describes a stainless steel display panel in which titanium oxide fine particles are fixed in a glaze layer provided on a stainless steel plate to prevent contamination. Also in this technology, titanium oxide fine particles, which are expected to have a photocatalytic function, are completely covered and fixed by a dense glass glaze layer, so that water or air does not reach the titanium oxide surface in the glaze layer and is contained. The photocatalytic function of some titanium oxides has not been fully demonstrated.
[0006]
By the way, when metal materials are applied to panels such as ceilings, walls, floors, etc. of toilets, washrooms or food sanitation factories, which are environmentally problematic, antibacterial properties, stain resistance, deodorizing properties, decomposability of organic substances, hydrophilicity. It is required to have a photocatalytic function having anti-fouling property, antifouling property, fingerprint resistance and the like.
In the above-mentioned method of forming a film, only a titanium oxide exposed on the outermost surface is formed because a film in a bulk state is formed or the titanium oxide fine particles are fixed by being covered with a dense binder layer and a glaze layer. The photocatalytic function has not been developed. This is because the immobilized film-like substance inhibits the surface reaction of titanium oxide.
The deodorizing and organic substance decomposing functions require an extremely high photocatalytic function and require a surface area as high as possible. Therefore, it is desirable that titanium oxide fine particles be present in a powder state and with the surface exposed. It is.
[0007]
The present invention has been devised in order to solve such a problem. An inorganic film containing titanium oxide fine particles is formed on a surface of a metal material in a manner that the exposed surface area is widened to provide a photocatalytic function. It is an object of the present invention to provide a metal material that can exhibit various functions.
[0008]
[Means for Solving the Problems]
In order to achieve the object, the metal material having excellent photocatalytic activity of the present invention is characterized in that a mica layer in which titanium oxide fine particles are dispersed is formed on the surface of a metal substrate.
The metal material having excellent photocatalytic activity can be obtained by subjecting the surface of the metal material to blast treatment using a mixed powder obtained by adding and mixing 0.5% by mass or more of titanium oxide fine powder to synthetic mica.
It is preferable to use a titanium oxide powder having an average particle diameter of 1.0 μm or less and a synthetic mica having a long diameter of 20 to 30 μm.
After forming the mica layer, it is preferable to further perform a blast treatment to densify the mica layer.
[0009]
[Action]
The present inventors have continued various studies on an inorganic material serving as a binder component and a film forming means for fixing a titanium oxide fine powder having a photocatalytic function to a metal material surface with an inorganic material.
As a result, it was confirmed that when the synthetic mica was sprayed by the blast method, the mica was crushed, and was brought into a semi-molten state by the mutual collision energy on the metal material surface, and was firmly fixed to the metal material surface.
At this time, if the fine titanium oxide powder is sufficiently stirred and mixed in advance in the synthetic mica, mica having titanium oxide adhered to the surface is obtained by electrostatic attraction of the mica having high electrical insulation. And when this mixed powder is blasted as a projection material, the titanium oxide fine powder is projected on the metal material surface while being attached to the mica surface, and held in a state of being embraced in the mica attached to the metal material surface, It will be fixed to the surface of the metal material.
[0010]
The coating structure on the surface will be described with reference to FIG.
The whole shows a fine porous mode. Since the mica has a low hardness (Mohs hardness: 3.4), the scaly shape is easily distorted by the blast treatment, and the mica is deposited in that state to show a porous form. At the time of the blast, the titanium oxide fine particles adhering to the mica are in a state of being taken into the inside as it is. For this reason, surface water and the atmosphere can enter the porous structure and easily reach the titanium oxide surface, and the titanium oxide present inside can also exhibit a photocatalytic function. That is, since the substantial surface area is larger than that in the bulk state or the state of being fixed by the dense bonding layer, an excellent photocatalytic function can be exhibited. Further, the outermost surface also has an uneven shape, which contributes to an increase in surface area.
[0011]
Since the titanium oxide fine particles are fixed on the surface of the metal material in a form incorporated in the porous mica layer, it is presumed that a sufficient photocatalytic function can be exhibited. In addition, since titanium oxide fine particles having a photocatalytic function are fixed with inorganic synthetic mica components, they have extremely good hydrophilicity.
The film formed according to the present invention has a stronger adhesion than the case where a binder component such as a coating film is used because the synthetic mica is in a semi-molten state by the impact energy of the blast and is firmly fixed to the surface of the metal material. ， Bendability tends to be high. In addition, the fingerprint is hardly conspicuous because the surface of the inorganic film has fine irregularities in which irregular reflection of light is suppressed, and the adhered fingerprint is easily decomposed and easily lost because of its high photocatalytic function. That is, the fingerprint resistance is also high. Further, it is considered that the antifouling property also increases with the high photocatalytic activity.
[0012]
Even if a film mainly composed of synthetic mica is formed by simply blasting, the film is not sufficient in terms of weather resistance (water resistance) because it is porous. Therefore, when applied to members requiring water resistance, etc., after forming a film mainly composed of synthetic mica, blasting using glass beads etc. will increase the density of the film, and rough surface unevenness Changes into dense and fine irregularities, so that weather resistance and adhesion strength are also improved.
[0013]
Embodiment
The metal material on which the titanium oxide fine particle-dispersed mica layer of the present invention is deposited is not particularly limited. Cold rolled carbon steel sheets, stainless steel sheets, aluminum alloy sheets, etc. can be used.
Basically, it is not necessary to apply a special pre-treatment to the metal material on which the titanium oxide fine particle-dispersed mica layer is applied by the blast treatment. However, if the surface has flaws, dirt, scale, etc. It is preferable to remove using a hard abrasive such as alumina.
[0014]
There is no particular limitation on the type of mica, which is the main component of the projectile. A mica having a desired color tone may be selected in consideration of design properties according to the application. The particle size of the mica is sufficient if the titanium oxide can be blasted together with the mica and has a kinetic energy sufficient to form a film.
As the titanium oxide to be used, any of rutile type and anatase type can be used, but in order to obtain an excellent photocatalytic function, it is preferable to use anatase type titanium oxide. In order to enhance the photocatalytic activity, it is preferable to use titanium oxide having a finer particle size. It is desirable to use one having a diameter of 1.0 μm or less.
The lower limit of the mixing ratio of the mica to the titanium oxide is about 5: 1 in terms of the mixing ratio in the shot material, and the mixing ratio of 0.5% by mass or more is possible from the ratio. In order to be efficiently fixed to the mica layer and exhibit an excellent photocatalytic function, it is preferable to mix the mica layer with mica at a ratio of 1 to 30% by mass.
[0015]
In order to homogenize the components in the film after the blast treatment, it is necessary to uniformly mix the mica and the titanium oxide of the shot material. It is necessary to prevent the mica from being crushed and to generate static electricity on the mica to adhere the titanium oxide fine particles. For this purpose, it is preferable to adopt a form in which each powder is charged into a container made of a synthetic resin, balls such as alumina and zirconia are simultaneously charged, and the container itself is rotated to mix.
As a device used for blasting, any type such as a pneumatic accelerator and a mechanical accelerator can be used. In consideration of the adhesion of the processing film and the projection efficiency, it is preferable to use a direct-pressure pneumatic accelerator capable of obtaining a higher projection speed.
[0016]
When a blast treatment with glass beads or the like is performed after the formation of a film mainly composed of synthetic mica to densify the film, soda glass of a general material is sufficient as a blast material to be used. It is preferable to use a spherical shape. In relation to the densification of the surface, it is preferable to use one having a particle size of about 0.1 mm.
Further, the projection pressure is preferably set to about 0.1 MPa in a range where the grinding action is not exhibited.
[0017]
【Example】
Example 1 :
90% by mass of synthetic mica (PDM-7-80, manufactured by Topy Industries, Ltd.) having a long diameter of 30 μm and 10% by mass of titanium oxide powder (P25, manufactured by Nippon Aerosil Co., Ltd.) having a particle size of 0.05 μm or less, and a self-made mixing device Then, an appropriate number of zirconia balls having a diameter of 10 mm was added so as to occupy about 30% with respect to the powder volume, and mixed and stirred for about 5 minutes to prepare a shot material.
A stainless steel having an adhesion layer on the surface is blasted for about 5 minutes using a direct-pressure blasting apparatus having an injection nozzle with a diameter of 10 mm using a BA finish material of SUS304 steel plate as a material to be projected, with an air pressure of 0.3 MPa for about 5 minutes. A steel plate was obtained.
After the blast treatment, the treated surface was subjected to elemental analysis using EPMA, and it was confirmed that Ti, in addition to Si, Al and O, was present on the surface.
Various characteristics of this coated metal material were investigated.
The same stainless steel sheet BA material was used as a comparative material.
The evaluation method and evaluation criteria for each characteristic are as shown in Table 1.
In Table 1, the salt dry / wet combined cycle test indicated as “CCT” was performed in a salt spray (5% NaCl, 10 minutes) → dry (60 ° C., 30% RH, 60 minutes) → wet (50 ° C., 95% RH, 180 minutes) as one cycle.
[0018]
Example 2
Using the synthetic mica, titanium oxide powder, mixing conditions, stainless steel plate, and blast conditions used in Example 1, only the mixing ratio of the titanium oxide powder was set to 0, 0.5, 1, 5, 10, 20, 25, 30. , 40, 50, 99% by mass to form a synthetic mica layer.
Then, various characteristics were investigated in the same manner as in Example 1.
Table 2 shows the results.
[0021]
Example 3
Spherical glass beads having an average particle diameter of 100 μm were further blasted at an injection pressure of 0.1 MPa on the steel sheet on which the titanium oxide dispersed mica layer formed in Example 1 was formed. These conditions are set within a range in which the grinding action can be suppressed and a pressing force can be applied.
The properties of the post-treated steel sheet were investigated in the same manner as in Example 1.
Table 4 shows the results.
The properties of the four items shown in this table were greatly improved by the glass bead blasting. Other characteristics were almost the same as those not subjected to the glass bead blasting treatment, and no deterioration of the characteristics was observed.
[0023]
【The invention's effect】
As described above, when titanium oxide fine particles having excellent photocatalytic activity are blasted on the surface of a metal material together with mica, a porous mica layer in which the titanium oxide fine particles are dispersed is formed on the surface of the metal material. By increasing the surface area of the titanium oxide fine particles in contact with the particles, the photocatalytic function can be maximized.
Further, since the mica layer to which titanium oxide is fixed is fixed to the metal material in a semi-molten state by blast treatment, the adhesion strength is high, so that the adhesion strength is high and the workability is excellent. In addition, since it has fine irregularities derived from the layer forming means, it has the original photocatalytic function such as hydrophilicity and anti-fingerprint property, and has multiple functions accompanying it. Can be greatly expanded.
[Brief description of the drawings]
FIG. 1 is a diagram schematically illustrating a cross-sectional structure of a metal material surface on which a titanium oxide dispersed mica layer is formed.
Claims (4)
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008226678A (en) * | 2007-03-14 | 2008-09-25 | Timios:Kk | Electrode material, its manufacturing method, ozone generation device, and ozone generation method |
| JP2016520161A (en) * | 2013-05-10 | 2016-07-11 | スリーエム イノベイティブ プロパティズ カンパニー | Method and composite article for depositing titania on a substrate |
Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0762559A (en) * | 1993-08-27 | 1995-03-07 | Inter Metallics Kk | Formation of powder film |
| JPH09253487A (en) * | 1996-03-26 | 1997-09-30 | Towa Denka Kogyo Kk | Clathrate catalyst and its preparation |
| JPH10323566A (en) * | 1997-05-23 | 1998-12-08 | Kunio Kitajima | Photocatalyst and its production |
| JPH10323569A (en) * | 1997-05-27 | 1998-12-08 | Kunio Kitajima | Photocatalytic ceramic material and its production |
| JP2000239829A (en) * | 1999-02-17 | 2000-09-05 | Sumitomo Metal Mining Co Ltd | Member with solid lubricating film |
| JP2001031913A (en) * | 1999-07-23 | 2001-02-06 | Toto Ltd | Coating composition and article coated therewith |
| WO2002036855A1 (en) * | 2000-10-23 | 2002-05-10 | National Institute Of Advanced Industrial Science And Technology | Composite structure and method for manufacture thereof |
-
2002
- 2002-07-15 JP JP2002205358A patent/JP3808409B2/en not_active Expired - Fee Related
Patent Citations (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0762559A (en) * | 1993-08-27 | 1995-03-07 | Inter Metallics Kk | Formation of powder film |
| JPH09253487A (en) * | 1996-03-26 | 1997-09-30 | Towa Denka Kogyo Kk | Clathrate catalyst and its preparation |
| JPH10323566A (en) * | 1997-05-23 | 1998-12-08 | Kunio Kitajima | Photocatalyst and its production |
| JPH10323569A (en) * | 1997-05-27 | 1998-12-08 | Kunio Kitajima | Photocatalytic ceramic material and its production |
| JP2000239829A (en) * | 1999-02-17 | 2000-09-05 | Sumitomo Metal Mining Co Ltd | Member with solid lubricating film |
| JP2001031913A (en) * | 1999-07-23 | 2001-02-06 | Toto Ltd | Coating composition and article coated therewith |
| WO2002036855A1 (en) * | 2000-10-23 | 2002-05-10 | National Institute Of Advanced Industrial Science And Technology | Composite structure and method for manufacture thereof |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2008226678A (en) * | 2007-03-14 | 2008-09-25 | Timios:Kk | Electrode material, its manufacturing method, ozone generation device, and ozone generation method |
| JP4719937B2 (en) * | 2007-03-14 | 2011-07-06 | 株式会社Ｔ＆Ｔプロダクツ | Electrode material and ozone generator |
| JP2016520161A (en) * | 2013-05-10 | 2016-07-11 | スリーエム イノベイティブ プロパティズ カンパニー | Method and composite article for depositing titania on a substrate |
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