JP2001070112A - Stainless steel mirror having excellent antifogging property and its production - Google Patents
Stainless steel mirror having excellent antifogging property and its productionInfo
- Publication number
- JP2001070112A JP2001070112A JP24687399A JP24687399A JP2001070112A JP 2001070112 A JP2001070112 A JP 2001070112A JP 24687399 A JP24687399 A JP 24687399A JP 24687399 A JP24687399 A JP 24687399A JP 2001070112 A JP2001070112 A JP 2001070112A
- Authority
- JP
- Japan
- Prior art keywords
- photocatalyst
- stainless steel
- coating film
- mirror
- boehmite
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Withdrawn
Links
Landscapes
- Mirrors, Picture Frames, Photograph Stands, And Related Fastening Devices (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、天候や気温の急変に拘
わらず鮮明な鏡像が観察される防曇性に優れたステンレ
ス鋼製鏡及びその製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stainless steel mirror excellent in anti-fog properties and capable of observing a clear mirror image regardless of a sudden change in weather or temperature, and a method of manufacturing the same.
【０００２】[0002]
【従来の技術】環境温度の急変によって鏡表面が結露す
ると曇りが発生し、鏡像が極めて不鮮明になる。鏡面の
結露は、鏡の温度が上昇するまで解消されないため、鏡
を使用する場合に鏡面をきれいにする煩わしい作業が要
求される。鏡の加熱により結露を防止できるが、加熱手
段を組み込むことから鏡の構造が複雑化すると共に、熱
エネルギーを消費する結果となる。結露水分が水滴とし
て留まることなく鏡面を流れ落ちるように、鏡面に親水
性を付与することによっても防曇性が改善される。たと
えば、ポリアクリル酸，ポリビニルアルコール等の水溶
性ポリマーに界面活性剤を配合した塗膜（特開昭５２−
１０１６８０号公報），紫外線照射後にアルカリ処理し
たポリマー層（実開平３−１２９６５７号公報），シリ
カゾル及びアルミナゾルの混合液から作られた塗膜（特
開平１０−１１４５４３号公報）等で親水性を付与する
ことが知られている。しかし、何れも長期間にわたって
良好な防曇性を維持することが困難であった。2. Description of the Related Art When the surface of a mirror is dewed due to a sudden change in environmental temperature, fogging occurs and the mirror image becomes extremely unclear. Since condensation on the mirror surface is not eliminated until the temperature of the mirror rises, a cumbersome operation of cleaning the mirror surface when using the mirror is required. Dew condensation can be prevented by heating the mirror, but incorporating the heating means complicates the structure of the mirror and consumes heat energy. By imparting hydrophilicity to the mirror surface, the antifogging property is also improved so that the dew condensation water flows down the mirror surface without remaining as water droplets. For example, a coating film obtained by blending a surfactant with a water-soluble polymer such as polyacrylic acid and polyvinyl alcohol (Japanese Patent Laid-Open No.
Japanese Patent Application Laid-Open No. 101680/1991, a polymer layer alkali-treated after irradiation with ultraviolet rays (Japanese Utility Model Application Laid-Open No. 3-129657), and a coating film made from a mixed solution of silica sol and alumina sol (Japanese Patent Application Laid-Open No. Hei 10-114543). It is known to However, it was difficult to maintain good antifogging properties over a long period of time.
【０００３】最近では、光触媒を含むシリカ塗膜を鏡面
に設け、光触媒の励起で塗膜を親水性にする方法が開発
されている（ＰＣＴ／ＪＰ９６／００７３）。この方法
によるとき、鏡面の対水接触角を１０度以下にできるた
め、結露水は鏡面に留まることなく流れ落ちる。しか
も、結露水の流下に必要な親水性は、光照射によって光
触媒が励起される限り継続する。シリカに替えて無定型
アルミナを用いた塗膜も提案されている（特開平９−２
２７８０５号公報）。Recently, a method has been developed in which a silica coating containing a photocatalyst is provided on a mirror surface and the coating is made hydrophilic by excitation of the photocatalyst (PCT / JP96 / 0073). According to this method, the water contact angle of the mirror surface can be made 10 degrees or less, and condensed water flows down without remaining on the mirror surface. Moreover, the required hydrophilicity under the flow of the dew water continues as long as the photocatalyst is excited by light irradiation. A coating film using amorphous alumina instead of silica has also been proposed (Japanese Patent Laid-Open No. 9-2).
27805).
【０００４】[0004]
【発明が解決しようとする課題】光触媒及びシリカを含
む塗膜は、光照射前にあっては対水接触角が８０度以上
の疎水性を呈し、光照射で始めて親水化する。光触媒の
励起で塗膜を親水性に維持する条件下で長時間使用する
と、光触媒の励起と共に、光触媒を結合している塗膜の
Ｓｉ−Ｏ結合が徐々に切断される。その結果、塗膜にク
ラックが発生し、白化現象や塗膜剥離が生じることがあ
る。白化現象や塗膜剥離は、鏡像の鮮映さが重要視され
る鏡にあっては大きな欠点となる。無定型アルミナをバ
インダとして使用した塗膜でも、光照射によって始めて
親水化する。無定型アルミナは、シリカほどの蓄水性が
ないため親水性の持続が不充分であり、遮光によって対
水接触角が大きくなる。しかも、長時間使用に供される
と、無定型アルミナの部分的な結晶化等に起因する白化
現象が発生する。A coating film containing a photocatalyst and silica exhibits a hydrophobic property with a contact angle with water of 80 degrees or more before light irradiation, and becomes hydrophilic only by light irradiation. When used for a long time under the condition that the coating film is kept hydrophilic by the excitation of the photocatalyst, the Si—O bond of the coating film binding the photocatalyst is gradually broken with the excitation of the photocatalyst. As a result, cracks may occur in the coating film, causing whitening and peeling of the coating film. The whitening phenomenon and the peeling of the coating film are serious drawbacks in mirrors where sharpness of the mirror image is important. Even a coating film using amorphous alumina as a binder is hydrophilized only by light irradiation. Amorphous alumina does not have the same water storage capacity as silica, so its hydrophilicity is not sufficiently maintained, and the contact angle with water increases due to shading. In addition, when used for a long period of time, a whitening phenomenon occurs due to partial crystallization of amorphous alumina.
【０００５】[0005]
【課題を解決するための手段】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、ベーマイト及び
／又はγアルミナをバインダとして使用することによ
り、成膜当初から対水接触角１０度以下の親水性を呈
し、親水性が高位に安定維持され、塗膜の安定性にも優
れたステンレス鋼製鏡を提供することを目的とする。本
発明のステンレス鋼製鏡は、その目的を達成するため、
鏡面仕上げしたステンレス鋼板を基材とし、光触媒粒子
がベーマイト及び／又はγアルミナで結着された光触媒
含有塗膜が前記基材の表面に形成されていることを特徴
とする。DISCLOSURE OF THE INVENTION The present invention has been devised to solve such a problem. By using boehmite and / or γ-alumina as a binder, water contact from the beginning of film formation can be achieved. An object of the present invention is to provide a stainless steel mirror exhibiting hydrophilicity of an angle of 10 degrees or less, stably maintaining hydrophilicity at a high level, and excellent in stability of a coating film. The stainless steel mirror of the present invention achieves its purpose,
A photocatalyst-containing coating film in which a mirror-finished stainless steel plate is used as a base material and photocatalyst particles are bound with boehmite and / or γ-alumina is formed on the surface of the base material.
【０００６】このステンレス鋼製鏡は、ベーマイトアル
ミナゾルに結晶性光触媒の粒子又は熱処理後に結晶性光
触媒の粒子となる前躯体を分散させた懸濁液を用意し、
鏡面仕上げしたステンレス鋼板に懸濁液を塗布し、次い
で結晶性光触媒の粒子がベーマイト及び／又はγアルミ
ナで結着された光触媒含有塗膜をステンレス鋼板の表面
に形成する熱処理を施すことにより製造される。光触媒
含有塗膜の形成に先立って、クリア塗膜からなる第１層
をステンレス鋼表面に設けてもよい。In this stainless steel mirror, a suspension is prepared by dispersing crystalline photocatalyst particles or precursors that become crystalline photocatalyst particles after heat treatment in boehmite alumina sol,
It is manufactured by applying a suspension to a mirror-finished stainless steel sheet and then performing a heat treatment to form a photocatalyst-containing coating film in which particles of crystalline photocatalyst are bound with boehmite and / or γ-alumina on the surface of the stainless steel sheet. You. Prior to forming the photocatalyst-containing coating film, a first layer made of a clear coating film may be provided on the stainless steel surface.
【０００７】[0007]
【作用】本発明者等は、光触媒−シリカ系及び光触媒ー
無定型アルミナ系の塗膜が成膜当初に親水性を示さない
原因を種々調査検討した。その結果、塗料組成物中の有
機物が成膜後にも塗膜に残存していることに原因がある
ものと考えた。そこで、塗料組成物に含まれる有機物を
極力少なく、且つ溶媒として含まれる有機物を３０重量
％以下に低減し、原料をベーマイトゾルとする塗料組成
物を検討した。ベーマイトゾルを用いて調製された塗料
組成物から作られた塗膜は、有機物をほとんど含んでい
ないため、光照射のない成膜当初でも親水性を発現す
る。The present inventors have investigated and investigated various causes of the lack of hydrophilicity of the photocatalyst-silica-based and photocatalyst-amorphous alumina-based coatings at the beginning of film formation. As a result, it was considered that the cause was that the organic matter in the coating composition remained in the coating film even after film formation. Therefore, a coating composition using boehmite sol as a raw material was studied, in which the amount of organic substances contained in the coating composition was reduced to a minimum and the amount of organic substances contained as a solvent was reduced to 30% by weight or less. Since a coating film made from a coating composition prepared using a boehmite sol contains almost no organic substances, it exhibits hydrophilicity even at the beginning of film formation without light irradiation.
【０００８】成膜当初からの親水性は、塗膜にほとんど
有機物が含まれておらず、ベーマイト及び／又はγアル
ミナがバインダとして光触媒粒子を結着していることに
原因があるものと推察される。ベーマイトやγアルミナ
は、空気中に水分が化学的及び物理的に結合し易いＯＨ
基をもつ構造になっていることから、良好な親水性を呈
する物質である。しかも、ポリシロキサンのＳｉ−Ｏ結
合エネルギー１０１．５ｋｃａｌ／ｍｏｌに比較してＡ
ｌ−Ｏ結合エネルギーが１３６ｋｃａｌ／ｍｏｌと大き
いため、光触媒の励起によって光触媒粒子を結着してい
るＡｌ−Ｏ結合が切断されることもない。しかも、ベー
マイトやγアルミナが成膜当初から所定の結晶構造をも
っているため、光照射を長時間継続させても構造変化が
生じることなく、塗膜の安定性も向上する。鏡面仕上げ
したステンレス鋼板の表面に第１層としてクリア塗膜を
設けた後で、光触媒含有塗膜を形成することもできる。It is presumed that the hydrophilicity from the beginning of film formation is due to the fact that boehmite and / or γ-alumina binds the photocatalyst particles as a binder since the coating film contains almost no organic matter. You. Boehmite and γ-alumina are OH in which moisture is easily chemically and physically bonded in the air.
Since it has a structure having a group, it is a substance exhibiting good hydrophilicity. Moreover, compared with the polysiloxane having an Si—O bond energy of 101.5 kcal / mol,
Since the l-O bond energy is as large as 136 kcal / mol, the Al-O bond binding the photocatalyst particles is not broken by the excitation of the photocatalyst. Moreover, since boehmite and γ-alumina have a predetermined crystal structure from the beginning of the film formation, even if light irradiation is continued for a long time, no structural change occurs and the stability of the coating film is improved. After providing a clear coating film as a first layer on the surface of a mirror-finished stainless steel plate, a photocatalyst-containing coating film can also be formed.
【０００９】[0009]
【実施の形態】基材として使用されるステンレス鋼板
は、鏡面仕上げした後で、塗膜密着性を改善するために
必要に応じて脱脂，リン酸塩処理，クロメート処理等の
前処理が施される。前処理されたステンレス鋼板に、光
触媒及びベーマイト及び／又はγアルミナを含む塗料組
成物を塗布し、加熱焼成すると親水性及び耐候性に優れ
た光触媒含有塗膜が形成される。光触媒としては、酸化
チタン，酸化亜鉛，チタン酸ストロンチウム，酸化タン
グステン，酸化スズ，酸化ジルコニウム等が使用可能で
あるが、化学的安定性や活性度の高さから酸化チタンの
使用が好ましい。光触媒は、塗膜中の含有量が１０〜６
０重量％の範囲になるように塗料組成物に配合される。
光触媒含有量が１０％未満では、光触媒活性が不充分
で、鏡面に付着した有機物に起因する親水性の劣化を光
触媒の励起で回復させるために長時間を要する。逆に６
０重量％を超える光触媒含有量では、光照射のない暗所
に保管したとき親水性が短時間で劣化し易くなる。BEST MODE FOR CARRYING OUT THE INVENTION A stainless steel sheet used as a base material is subjected to a pre-treatment such as degreasing, phosphate treatment, and chromate treatment as required after a mirror finish to improve coating film adhesion. You. When a coating composition containing a photocatalyst and boehmite and / or γ-alumina is applied to a pretreated stainless steel plate and heated and fired, a photocatalyst-containing coating film having excellent hydrophilicity and weather resistance is formed. As the photocatalyst, titanium oxide, zinc oxide, strontium titanate, tungsten oxide, tin oxide, zirconium oxide, and the like can be used, but titanium oxide is preferably used because of its high chemical stability and high activity. The content of the photocatalyst in the coating film is 10 to 6
It is blended with the coating composition so as to be in a range of 0% by weight.
When the content of the photocatalyst is less than 10%, the photocatalytic activity is insufficient, and it takes a long time to recover the deterioration of hydrophilicity due to the organic substance attached to the mirror surface by excitation of the photocatalyst. Conversely 6
If the content of the photocatalyst exceeds 0% by weight, the hydrophilicity tends to deteriorate in a short time when stored in a dark place without light irradiation.
【００１０】光触媒含有塗膜は、光触媒の他にベーマイ
ト及び／又はγアルミナを含む。ベーマイト及びγアル
ミナの割合は特に規定されるものではないが、短時間で
親水性を発現させる上ではベーマイトに比較して当量以
上のγアルミナを含ませることが好ましい。光触媒含有
塗膜は、次のような方法で形成される。粒径１０ｎｍ以
下のベーマイトを水又は水／アルコール等の溶媒に分散
させてベーマイトアルミナゾルとし、粒径１０ｎｍ以下
の結晶性光触媒粒子をベーマイトアルミナゾルに更に分
散させることにより懸濁液を調製する。ステンレス鋼板
に懸濁液を塗布し、２００〜６００℃で熱処理すると
き、透明な光触媒含有塗膜が形成される。必要強度の塗
膜を得る上で２００℃以上の熱処理温度が好ましく、熱
処理温度が２００℃を下回ると剥離し易い塗膜が形成さ
れる。逆に６００℃を超える熱処理温度では、アルミナ
の結晶形態が変化して表面のＯＨ基が減少するため親水
性が劣化する傾向が示される。[0010] The photocatalyst-containing coating film contains boehmite and / or gamma alumina in addition to the photocatalyst. The proportions of boehmite and γ-alumina are not particularly limited, but it is preferable to include γ-alumina in an equivalent amount or more as compared with boehmite in order to develop hydrophilicity in a short time. The photocatalyst-containing coating film is formed by the following method. A suspension is prepared by dispersing boehmite having a particle size of 10 nm or less in a solvent such as water or water / alcohol to form a boehmite alumina sol, and further dispersing crystalline photocatalytic particles having a particle size of 10 nm or less in the boehmite alumina sol. When a suspension is applied to a stainless steel plate and heat-treated at 200 to 600 ° C., a transparent photocatalyst-containing coating film is formed. A heat treatment temperature of 200 ° C. or higher is preferred for obtaining a coating film having the required strength. When the heat treatment temperature is lower than 200 ° C., a coating film that is easily peeled is formed. Conversely, if the heat treatment temperature exceeds 600 ° C., the crystal form of alumina changes and the number of OH groups on the surface decreases, so that the hydrophilicity tends to deteriorate.
【００１１】光触媒粒子の原料には、熱処理後に光触媒
性酸化物となる前躯体を使用することもできる。このよ
うな前躯体としては、各種金属アルコキシド，金属塩を
出発原料として加水分解で得られる金属水酸化物等があ
る。たとえば、ＴｉＯ2を光触媒性酸化物とする場合、
チタンテトライソプロポキシド，Ｔｉ（ＯＨ）4等を原
料として配合した塗料組成物をステンレス鋼板に塗布
し、熱処理する。このとき、熱処理温度を４００〜６０
０℃にするとＴｉＯ2がアナターゼ型の結晶構造にな
り、優れた光触媒活性、ひいては良好な親水性が付与さ
れる。As a raw material of the photocatalyst particles, a precursor which becomes a photocatalytic oxide after heat treatment can be used. Examples of such precursor include metal hydroxides obtained by hydrolysis using various metal alkoxides and metal salts as starting materials. For example, when TiO 2 is used as a photocatalytic oxide,
A coating composition containing titanium tetraisopropoxide, Ti (OH) 4 or the like as a raw material is applied to a stainless steel plate and heat-treated. At this time, the heat treatment temperature is set to 400 to 60.
At 0 ° C., TiO 2 has an anatase-type crystal structure, giving excellent photocatalytic activity and, consequently, good hydrophilicity.
【００１２】ステンレス鋼板表面に設けたクリア塗膜の
上に光触媒含有塗膜を形成する場合、屈折率の低い透明
な酸化物塗膜をクリア塗膜とすることが好ましい。酸化
物塗膜は、たとえばシリカ，アルミナ，ゼオライト，酸
化スズ等を原料とするゾル状の塗料組成物をステンレス
鋼板に塗布し、加熱焼成することにより形成される。こ
のとき、塗料組成物に含まれている水酸化物の水酸基が
前処理されたステンレス鋼の表面に存在するＯＨ基と脱
水縮合反応し、ステンレス鋼板表面に対し強固な化学結
合性でクリア塗膜が付着する。クリア塗膜の表面にもＯ
Ｈ基があるため、その上に形成される光触媒含有塗膜と
の間の化学結合性も改善され、光触媒含有塗膜の密着性
が向上する。When a photocatalyst-containing coating film is formed on a clear coating film provided on the surface of a stainless steel plate, a transparent oxide coating film having a low refractive index is preferably used as the clear coating film. The oxide coating film is formed, for example, by applying a sol-like coating composition using silica, alumina, zeolite, tin oxide, or the like as a raw material to a stainless steel plate and heating and baking. At this time, the hydroxyl group of the hydroxide contained in the coating composition undergoes a dehydration-condensation reaction with the OH group present on the surface of the pretreated stainless steel, and a clear coating film having strong chemical bonding to the surface of the stainless steel plate. Adheres. O on clear coating surface
Due to the presence of the H group, the chemical bond with the photocatalyst-containing coating film formed thereon is also improved, and the adhesion of the photocatalyst-containing coating film is improved.
【００１３】[0013]
【実施例】成膜例１（本発明例）：バフ研磨により板厚
０．８ｍｍのＳＵＳ３０４ステンレス鋼板を鏡面仕上げ
した後、アルカリ脱脂及びクロメート処理を施し、水
洗，乾燥した。次いで、粒径７ｎｍのアナターゼ型Ｔｉ
Ｏ2粒子をベーマイトアルミナゾルに分散させた懸濁液
をステンレス鋼板に塗布し、３００℃で３０分間加熱焼
成することにより光触媒含有塗膜を形成した。 成膜例２（本発明例）：同じステンレス鋼板にベーマイ
トアルミナゾルを塗布して２５０℃で２０分間加熱焼成
することによりプライマ塗膜を形成した後で、成膜例１
と同じ条件下で光触媒含有塗膜を形成した。EXAMPLES Film forming example 1 (Example of the present invention): A SUS304 stainless steel sheet having a thickness of 0.8 mm was mirror-finished by buffing, subjected to alkali degreasing and chromate treatment, washed with water and dried. Then, anatase type Ti having a particle size of 7 nm
A suspension in which O 2 particles were dispersed in boehmite alumina sol was applied to a stainless steel plate, and heated and baked at 300 ° C. for 30 minutes to form a photocatalyst-containing coating film. Film-forming example 2 (Example of the present invention): Film-forming example 1 after applying a boehmite alumina sol to the same stainless steel plate and heating and baking at 250 ° C. for 20 minutes to form a primer coating film.
A photocatalyst-containing coating film was formed under the same conditions as described above.
【００１４】成膜例３（本発明例）：チタンテトライソ
プロポキシドをイソプロパノールに溶解し、ジイソプロ
パノールアミンを添加し、チタニアゾル及びベーマイト
アルミナゾルの混合液を調製した。得られた混合液を成
膜例１と同じ条件下でステンレス鋼板に塗布し、４００
℃で３分間加熱焼成することにより光触媒含有塗膜を形
成した。 成膜例４（本発明例）：同じステンレス鋼板にシリカゾ
ルを塗布して、２５０℃で２０分間加熱焼成することに
よりプライマ塗膜を形成した後、成膜例１と同じ条件下
で光触媒含有塗膜を形成した。Film forming example 3 (Example of the present invention): Titanium tetraisopropoxide was dissolved in isopropanol, diisopropanolamine was added, and a mixed solution of titania sol and boehmite alumina sol was prepared. The resulting mixture was applied to a stainless steel plate under the same conditions as in Film Formation Example 1 and
A photocatalyst-containing coating film was formed by heating and baking at 3 ° C. for 3 minutes. Film forming example 4 (Example of the present invention): A silica sol was applied to the same stainless steel plate, and heated and baked at 250 ° C. for 20 minutes to form a primer coating film. A film was formed.
【００１５】成膜例５（比較例）：テトラエトキシシラ
ンをエタノールに溶解してシリカゾルとし、粒径７ｎｍ
のアナターゼ型ＴｉＯ2粒子を分散させて懸濁液を調製
した。この懸濁液を成膜例１と同じ条件下でステンレス
鋼板に塗布し、３００℃で３０分間加熱焼成することに
より光触媒含有塗膜を形成した。 成膜例６（比較例）：ステンレス鋼板に成膜例４のプラ
イマ塗膜を設けた後、成膜例５と同じ条件下で光触媒含
有塗膜を形成した。 成膜例７（比較例）：アルミニウムイソプロポキシドを
エタノールに溶解して得たアルミナゾルに粒径７ｎｍの
アナターゼ型ＴｉＯ2粒子を分散させた懸濁液を調製し
た。懸濁液を成膜例１と同じ条件下でステンレス鋼板に
塗布し、３００℃で３０分間加熱焼成することにより無
定型アルミナ及び酸化チタンからなる光触媒含有塗膜を
形成した。 成膜例８（比較例）：ステンレス鋼板にシリカゾルを塗
布して、２５０℃で２０分間加熱焼成することによりプ
ライマ塗膜を形成した後、成膜例７と同じ条件下で光触
媒含有塗膜を形成した。Film forming example 5 (comparative example): tetraethoxysilane was dissolved in ethanol to form a silica sol, and the particle size was 7 nm.
Suspension was prepared by dispersing anatase TiO 2 particles. This suspension was applied to a stainless steel plate under the same conditions as in Film Formation Example 1, and heated and baked at 300 ° C. for 30 minutes to form a photocatalyst-containing coating film. Film forming example 6 (comparative example): After providing the primer coating film of film forming example 4 on a stainless steel plate, a photocatalyst-containing coating film was formed under the same conditions as in film forming example 5. Film-forming example 7 (comparative example): A suspension in which anatase-type TiO 2 particles having a particle diameter of 7 nm were dispersed in an alumina sol obtained by dissolving aluminum isopropoxide in ethanol was prepared. The suspension was applied to a stainless steel plate under the same conditions as in Film Formation Example 1, and heated and baked at 300 ° C. for 30 minutes to form a photocatalyst-containing coating film composed of amorphous alumina and titanium oxide. Film forming example 8 (comparative example): A silica sol was applied to a stainless steel plate, and heated and baked at 250 ° C. for 20 minutes to form a primer coating film. Formed.
【００１６】成膜例１〜８で得られた各防曇ステンレス
鋼製鏡から試験片を切り出し、次の試験で干渉色，光沢
度，成膜当初の親水性，親水性の持続度，塗膜の耐候性
を調査した。 干渉色試験：種々の角度から試験片を観察し、正面や水
平方向の何れの方向から見ても干渉色が検出されないも
のを◎，正面視では干渉色がなくても水平方向に見た場
合に僅かに干渉色が検出されたものを○，何れの方向か
ら見ても干渉色が検出されたものを×と評価した。 光沢度試験：入射角２０度で試験片表面の鏡面光沢度を
測定した。A test piece was cut out from each of the anti-fog stainless steel mirrors obtained in the film forming examples 1 to 8, and the interference color, glossiness, hydrophilicity at the time of film formation, persistence of hydrophilicity, The weather resistance of the film was investigated. Interference color test: Observation of the test specimen from various angles, and when no interference color is detected when viewed from either the front or horizontal direction, ◎, when viewed in the horizontal direction without interference color in front view When the interference color was slightly detected, it was evaluated as ○, and when the interference color was detected in any direction, it was evaluated as x. Glossiness test: The specular glossiness of the test piece surface was measured at an incident angle of 20 degrees.
【００１７】親水性試験：成膜当初の親水性を調査する
ため、試験片の塗膜面に水滴を滴下し、塗膜，水滴及び
空気の３相の接触点で水滴に引いた接線と塗膜面とのな
す角度のうち、液体を含む方の角度を対水接触角として
測定した。 親水性持続度試験：波長３６５ｎｍでの紫外線強度が１
７ｍＷ／ｃｍ2の水銀ランプで試験片を２時間照射した
後、光の当たらない暗所に試験片を保管し、１日経過後
の対水接触角を測定した。そして、１日経過後の対水接
触角が１０度以下の場合を○，１０度を超えた場合を×
として、親水性の持続度を評価した。 耐候性試験：試験片を６３℃のサンシャインウエザー試
験に供し、２０００時間経過後の塗膜性状を調査した。
そして、異常がなく透明な塗膜のままであったものを
○，クラックや白化が検出されたものを×として塗膜の
耐候性を評価した。Hydrophilicity test: In order to investigate the hydrophilicity at the beginning of film formation, a water drop was dropped on the coating surface of the test piece, and a tangent drawn to the water droplet at the contact point of the three phases of the coating film, the water droplet and air. Among the angles made with the film surface, the angle containing the liquid was measured as the contact angle with water. Hydrophilicity persistence test: UV intensity at a wavelength of 365 nm is 1
After irradiating the test piece with a 7 mW / cm 2 mercury lamp for 2 hours, the test piece was stored in a dark place not exposed to light, and the contact angle with water after one day was measured. When the contact angle with water after one day has passed is less than 10 degrees, the result is ○. When the contact angle exceeds 10 degrees, the result is ×.
, The degree of hydrophilicity was evaluated. Weather resistance test: The test piece was subjected to a sunshine weather test at 63 ° C., and the properties of the coating film after lapse of 2,000 hours were examined.
Then, the weather resistance of the coating film was evaluated as “O” when the transparent coating film remained without any abnormality, and as “X” when the crack or whitening was detected.
【００１８】表１の調査結果にみられるように、本発明
に従った試験番号１〜１６の防曇性鏡は、何れも対水接
触角が１０度未満と低い値を示し、親水性の持続度及び
耐候性も良好であった。光沢度も、シリカ−チタニア系
又は無定型アルミナ−チタニア系の光触媒含有塗膜を形
成した試験番号１７〜２０（比較例）に比較して遜色な
かった。ただし、比較的薄い光触媒含有塗膜を直接形成
した試験番号１，９では、干渉色が検出された。この干
渉色は、試験番号５，１３に見られるように、同じ膜厚
の光触媒含有塗膜を形成した場合にあっても、間にプラ
イマ層を介在させることによって解消した。As can be seen from the survey results in Table 1, all of the anti-fog mirrors of Test Nos. 1 to 16 according to the present invention have a low contact angle with respect to water of less than 10 degrees and have a low hydrophilicity. The durability and weather resistance were also good. The gloss was comparable to that of Test Nos. 17 to 20 (Comparative Examples) in which a silica-titania-based or amorphous alumina-titania-based photocatalyst-containing coating film was formed. However, in Test Nos. 1 and 9 in which a relatively thin photocatalyst-containing coating film was directly formed, interference colors were detected. As shown in Test Nos. 5 and 13, this interference color was eliminated by interposing a primer layer between the photocatalyst-containing coating films having the same film thickness.
【００１９】これに対し、シリカ−チタニア系塗膜をス
テンレス鋼表面に直接形成した試験番号１７では、干渉
色が検出され、２０００時間のサンシャインウエザー試
験で塗膜にクラックや白化が生じていた。プライマ層を
介して比較的厚膜のシリカ−チタニア系塗膜を設けた試
験番号１８では、干渉色は解消されたが、依然として耐
候性に劣る塗膜であった。無定型アルミナ−チタニア系
塗膜をステンレス鋼表面に直接形成した試験番号１９で
は、干渉色が検出され、暗所保管後の親水性が低下して
おり、２０００時間のサンシャインウエザー試験で塗膜
にクラックや白化が生じていた。プライマ層を介して比
較的厚膜の無定型アルミナ−チタニア系塗膜を設けた試
験番号２０では、干渉色は解消されたが、依然として親
水性の持続度及び耐候性に劣る塗膜であった。On the other hand, in Test No. 17, in which a silica-titania coating film was formed directly on the surface of stainless steel, an interference color was detected, and cracks and whitening occurred in the coating film in a 2000-hour sunshine weather test. In Test No. 18, in which a relatively thick silica-titania coating film was provided via the primer layer, the interference color was eliminated, but the coating film was still poor in weather resistance. In Test No. 19, in which an amorphous alumina-titania coating film was directly formed on the stainless steel surface, an interference color was detected and the hydrophilicity after storage in a dark place was reduced, and the coating film was subjected to a 2000-hour sunshine weather test. Cracks and whitening had occurred. In Test No. 20, in which a relatively thick amorphous alumina-titania-based coating film was provided via the primer layer, the interference color was eliminated, but the coating film still had poor hydrophilicity persistence and poor weather resistance. .
【００２０】 [0020]
【００２１】[0021]
【発明の効果】以上に説明したように、本発明のステン
レス鋼製鏡は、成膜当初から対水接触角１０度以下の優
れた親水性を呈する光触媒含有塗膜が表面に形成されて
いるため、紫外線照射なしでも優れた防曇性を示す。高
い親水性は、太陽光等の光源で照射される環境下では長
期間にわたって持続し、暗所に保管した場合でも１日以
上保持される。しかも、塗膜の耐候性が良好であるた
め、長期間にわたって優れた防曇性を示すステンレス鋼
製鏡となる。このステンレス鋼製鏡を自動車用サイドミ
ラーに使用すると、降雨時にもミラーの曇りがなく、自
動車の安全な運転が保証される。また、石がぶつかった
り、車同士の接触等でミラーが割れないため、カーブミ
ラーとしても使用できる。As described above, in the stainless steel mirror of the present invention, a photocatalyst-containing coating film having excellent hydrophilicity with a contact angle with water of 10 ° or less is formed on the surface from the beginning of film formation. Therefore, it exhibits excellent anti-fogging properties without UV irradiation. The high hydrophilicity lasts for a long time under an environment irradiated with a light source such as sunlight, and is maintained for one day or more even when stored in a dark place. In addition, since the weather resistance of the coating film is good, a stainless steel mirror having excellent anti-fog properties over a long period of time is obtained. When this stainless steel mirror is used for an automobile side mirror, the mirror is not fogged even during rainfall, and safe operation of the automobile is guaranteed. In addition, since the mirror does not break due to collision of stones or contact between vehicles, it can be used as a curved mirror.
Claims (2)
し、光触媒粒子がベーマイト及び／又はγアルミナで結
着された光触媒含有塗膜が前記基材の表面に形成されて
いることを特徴とする防曇性に優れたステンレス鋼製
鏡。1. A photocatalyst-containing coating comprising a mirror-finished stainless steel plate as a base material and photocatalyst particles bound with boehmite and / or γ-alumina formed on the surface of the base material. Stainless steel mirror with excellent cloudiness.
の粒子又は熱処理後に結晶性光触媒の粒子となる前躯体
を分散させた懸濁液を用意し、鏡面仕上げしたステンレ
ス鋼板に前記懸濁液を塗布し、次いで前記結晶性光触媒
の粒子がベーマイト及び／又はγアルミナで結着された
光触媒含有塗膜を前記ステンレス鋼板の表面に形成する
熱処理を施すことを特徴とする防曇性に優れたステンレ
ス鋼製鏡の製造方法。2. A suspension prepared by dispersing crystalline photocatalyst particles or a precursor that becomes crystalline photocatalyst particles after heat treatment in boehmite alumina sol, applying the suspension to a mirror-finished stainless steel plate, Next, a heat treatment for forming a photocatalyst-containing coating film in which the particles of the crystalline photocatalyst are bound with boehmite and / or γ-alumina on the surface of the stainless steel sheet is performed, and the stainless steel mirror having excellent antifogging properties is provided. Manufacturing method.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24687399A JP2001070112A (en) | 1999-09-01 | 1999-09-01 | Stainless steel mirror having excellent antifogging property and its production |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP24687399A JP2001070112A (en) | 1999-09-01 | 1999-09-01 | Stainless steel mirror having excellent antifogging property and its production |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JP2001070112A true JP2001070112A (en) | 2001-03-21 |
Family
ID=17155014
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP24687399A Withdrawn JP2001070112A (en) | 1999-09-01 | 1999-09-01 | Stainless steel mirror having excellent antifogging property and its production |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2001070112A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005290369A (en) * | 2004-03-10 | 2005-10-20 | Central Japan Railway Co | Titanium oxide-coating agent, and forming method for titanium oxide-coating film |
| US8048511B2 (en) | 2005-03-09 | 2011-11-01 | Central Japan Railway Company | Titanium oxide coating agent and titanium oxide film forming method |
-
1999
- 1999-09-01 JP JP24687399A patent/JP2001070112A/en not_active Withdrawn
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2005290369A (en) * | 2004-03-10 | 2005-10-20 | Central Japan Railway Co | Titanium oxide-coating agent, and forming method for titanium oxide-coating film |
| US8048511B2 (en) | 2005-03-09 | 2011-11-01 | Central Japan Railway Company | Titanium oxide coating agent and titanium oxide film forming method |
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