JPH10244622A - Anti-corrosion method of steel material - Google Patents
Anti-corrosion method of steel materialInfo
- Publication number
- JPH10244622A JPH10244622A JP9048721A JP4872197A JPH10244622A JP H10244622 A JPH10244622 A JP H10244622A JP 9048721 A JP9048721 A JP 9048721A JP 4872197 A JP4872197 A JP 4872197A JP H10244622 A JPH10244622 A JP H10244622A
- Authority
- JP
- Japan
- Prior art keywords
- steel material
- coating
- conductive
- anticorrosion
- coating film
- 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.)
- Granted
Links
Abstract
Description
【０００１】[0001]
【発明の属する技術分野】本発明は、橋梁や、プラン
ト、建築鉄骨等の大気中に存在する鋼構造物の鋼材の防
食方法に関し、特に鋼材を長期間効果的に腐食から保護
できる外部電源方式による電気防食法を利用する鋼材の
防食方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for preventing corrosion of steel in a steel structure existing in the air such as a bridge, a plant, a building steel frame, etc., and more particularly, to an external power supply system capable of effectively protecting steel from corrosion for a long period of time. The present invention relates to an anticorrosion method for a steel material using an electrolytic anticorrosion method.
【０００２】[0002]
【従来の技術】従来から海洋鋼構造物や、土壌中の鋼構
造物の防食方法の一方法として、外部電源方式や、流電
陽極方式による電気防食方法が広く利用されている。一
方、大気環境にある鋼構造物に対しては、海洋鋼構造物
や土壌中の鋼構造物のように水に接触しておらず、それ
故防食電流の経路の確保が困難とされ、電気防食方法は
全く利用されていなかった。従って、大気中に存在する
鋼構造物は、通常、防食塗料の塗装による防食方法が主
流となっている。しかしながら、防食塗料の塗装による
防食方法は、塗装不良や、鋼材表面が粗面となっている
場合、ピンホール等の塗膜欠陥が生じやすく、また機械
的な損傷部が生じやすく、このような欠陥部から腐食が
発生するといった問題点があった。そのため、防食塗料
を４〜６回程度塗り重ねる重防食塗装システムも利用さ
れている。しかしながら、このように複数回塗り重ねを
行う方法では、塗装回数や工数が増加し、塗装工程上の
問題点があった。2. Description of the Related Art Conventionally, as an anticorrosion method for a marine steel structure or a steel structure in soil, an external power supply system or a galvanic anode system has been widely used. On the other hand, steel structures in the atmospheric environment do not come into contact with water like marine steel structures and steel structures in soil, which makes it difficult to secure a route for anticorrosion current. No anticorrosion method was used at all. Therefore, for a steel structure existing in the atmosphere, an anticorrosion method by applying an anticorrosion paint is mainly used. However, the method of anticorrosion by applying anticorrosion paint is poor in coating or when the steel surface is rough, coating defects such as pinholes are likely to occur, and mechanical damage is likely to occur. There was a problem that corrosion occurred from the defective portion. For this reason, a heavy-duty anticorrosion coating system in which an anticorrosion paint is applied about 4 to 6 times is also used. However, in such a method of performing recoating a plurality of times, the number of coatings and the number of steps are increased, and there is a problem in the coating process.
【０００３】[0003]
【発明が解決しようとする課題】従って、本発明は、こ
のような従来技術の課題を背景になされたものであり、
無塗装の鋼材に対しても、あるいはピンホール等の塗膜
欠陥のある塗装された鋼材に対しても、大気中に存在す
る鋼材を長期間腐食から保護できる防食方法を提供する
ことを目的とする。SUMMARY OF THE INVENTION Accordingly, the present invention has been made in view of such problems of the prior art.
An object of the present invention is to provide an anticorrosion method capable of protecting steel present in the atmosphere from corrosion for a long time, even for unpainted steel or for coated steel having coating film defects such as pinholes. I do.
【０００４】[0004]
【課題を解決するための手段】本発明者等は、前記課題
を解決するため鋭意検討した結果、腐食が進行するのは
降雨時あるいは結露時など水が存在する場合であり、そ
の時に腐食電流の経路の確保ができていれば腐食を防止
できるとの想定のもとに、既に特願平８−２７２１２６
号明細書にて大気中に存在する塗装又は未塗装の鋼材表
面に表面抵抗値が１０7 Ω／cm2 以下の導電性塗膜又は
水に対する接触角が７０度以下の親水性塗膜、もしくは
両者の特性を同時に満足する塗膜を形成させ、外部電源
方式による電気防食法によって防食電流を流すことを特
徴とする鋼材の防食方法に関する出願をしている。しか
しながら、この出願に係る方法においては、日照時に防
食電流は十分とは言えず、部分的に水分、腐食性物質が
凝縮したような場所に十分に電気防食の効果が及ぶとは
言えない。そこで、本発明者らは光導電効果に着目し、
日照時の導電性をこれで補うことにより、乾燥時におい
ても十分に電気防食が達成される方法を見い出し、本発
明を完成したものである。The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, corrosion progresses when water is present such as during rainfall or dew condensation. Assuming that it would be possible to prevent corrosion if the route was secured, Japanese Patent Application No. 8-272126 had already been adopted.
According to the specification, a conductive coating having a surface resistance of 10 7 Ω / cm 2 or less or a hydrophilic coating having a contact angle to water of 70 ° or less is applied to the surface of a painted or unpainted steel material existing in the air, or An application has been filed for a method for preventing corrosion of steel, characterized in that a coating film that satisfies both characteristics is formed at the same time, and an anticorrosion current is applied by an anticorrosion method using an external power supply system. However, in the method according to the present application, the anticorrosion current during sunshine is not sufficient, and the effect of cathodic protection does not sufficiently reach places where moisture and corrosive substances are partially condensed. Therefore, the present inventors focused on the photoconductive effect,
By supplementing the conductivity during sunshine with this, a method has been found in which sufficient electrolytic protection is achieved even during drying, and the present invention has been completed.
【０００５】即ち、本発明は、大気中に存在する塗装又
は未塗装の鋼材表面に、光導電性を有する金属化合物粉
末５〜８０重量％を含み、かつ表面抵抗値が１０7 Ω／
cm2以下の導電性塗膜又は水に対する接触角が７０度以
下の親水性塗膜を形成させ、外部電源方式による電気防
食法によって防食電流を流すことを特徴とする鋼材の防
食方法に関するものである。That is, according to the present invention, a coated or unpainted steel material present in the atmosphere contains 5 to 80% by weight of a metal compound powder having photoconductivity and has a surface resistance of 10 7 Ω /.
The present invention relates to a method for preventing corrosion of steel, characterized in that a conductive coating having a size of 2 cm or less or a hydrophilic coating having a contact angle of 70 ° or less with water is formed, and an anticorrosion current is applied by an external anti-corrosion method. is there.
【０００６】[0006]
【発明の実施の形態】本発明において、導電性塗膜は、
外部電源により防食電流が流れるようにするために、塗
装又は未塗装の鋼材表面に形成される。この観点から、
導電性塗膜の表面抵抗値は、光の照射の有無にかかわら
ず、１０7 Ω／cm2 以下、好ましくは１０5 Ω／cm2 以
下とすることが必要がある。導電性塗膜を形成する塗料
としては、例えば、ポリアニリンや、ポリピロール、ポ
リチオフェン、ポリ−p −フェニレンビニレン、ポリア
セチレン等の導電性バインダー樹脂等や、カーボンブラ
ック、黄銅、アルミニウム、酸化亜鉛、グラファイト等
の粉末状、フレーク状あるいは繊維状の導電性充填剤を
配合して前記表面抵抗値範囲の導電性を付与した塗料が
挙げられる。導電性塗膜の表面抵抗値は、これらの材料
を適宜選択することによって調整することができる。BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a conductive coating film comprises
It is formed on a painted or unpainted steel surface so that an anticorrosion current flows from an external power supply. From this perspective,
The surface resistance value of the conductive coating film needs to be 10 7 Ω / cm 2 or less, preferably 10 5 Ω / cm 2 or less, regardless of the presence or absence of light irradiation. Examples of the paint for forming the conductive coating film include polyaniline, polypyrrole, polythiophene, poly-p-phenylenevinylene, a conductive binder resin such as polyacetylene, and carbon black, brass, aluminum, zinc oxide, graphite, and the like. Examples of the paint include a powdery, flake-like, or fibrous conductive filler, which is imparted with conductivity in the above-mentioned surface resistance value range. The surface resistance of the conductive coating can be adjusted by appropriately selecting these materials.
【０００７】本発明で使用される親水性塗膜は、導電性
塗膜と同様に、外部電源により防食電流が流れるように
するために使用され、塗装又は未塗装の鋼材表面に形成
する。そのため、親水性塗膜は、水に対する接触角が７
０度以下、好ましくは４０度以下である必要がある。親
水性塗膜を形成する塗料としては、水酸基や、カルボキ
シル基、アミノ基、カルボニル基、スルホン基等の親水
基を有する水溶性もしくは水分散性のアクリル系や、エ
ポキシ系、ポリエステル系、アルキド系、ウレタン系、
フェノール系、ポリエーテル系、ポリアミド系、ポリビ
ニルアルコール系、もしくはこれらを変性したバインダ
ー樹脂（場合によりメラミン樹脂や、ポリイソシアネー
ト化合物、ポリエチレンイミン等の架橋剤を併用しても
よい。）や、界面活性剤などを配合して、塗膜を形成し
た時に水に対する接触角が７０度以下、好ましくは４０
度以下となるような親水性を付与する塗料が挙げられ
る。[0007] The hydrophilic coating film used in the present invention, like the conductive coating film, is used to allow an anticorrosion current to flow by an external power supply, and is formed on a painted or unpainted steel material surface. Therefore, the hydrophilic coating film has a water contact angle of 7
It must be 0 ° or less, preferably 40 ° or less. Water-soluble or water-dispersible acrylics having a hydroxyl group, a carboxyl group, an amino group, a carbonyl group, a hydrophilic group such as a sulfone group, epoxy-based, polyester-based, and alkyd-based paints for forming a hydrophilic coating film. , Urethane,
Phenol-based, polyether-based, polyamide-based, polyvinyl-alcohol-based, or modified binder resin thereof (a melamine resin, a polyisocyanate compound, polyethyleneimine, or another crosslinking agent may be used in some cases) or surface activity The contact angle with water when forming a coating film is 70 degrees or less, preferably 40
And a coating material that imparts hydrophilicity to a degree of at most.
【０００８】このような導電性塗膜又は親水性塗膜を形
成する塗料に、塗膜乾燥時にも防食電流が流れる様、本
発明においては光導電性を有する金属化合物粉末を配合
する。光導電性を有する金属化合物とは、太陽光（特に
紫外光）などの光エネルギーを吸収すると半導体特性を
示して導電性となる金属化合物である。このような金属
化合物としては、TiO2等のチタン化合物や、ZnS 、ZnSe
等の亜鉛化合物、CdS 、CdTe等のカドミウム化合物など
の金属化合物、例えばこれらの酸素、硫黄、セレン若し
くはテルル化合物が代表的なものとして挙げられる。特
に本発明においては、安価で、耐汚染性をも有するアナ
ターゼ型酸化チタン粉末が好ましい。金属化合物粉末の
平均粒径は、好ましくは、0.００１〜３０μm 、特に好
ましくは0.１〜１０μm であることが適当である。In the present invention, a photoconductive metal compound powder is blended with the paint for forming such a conductive coating film or the hydrophilic coating film so that an anticorrosion current flows even when the coating film is dried. The metal compound having photoconductivity is a metal compound which exhibits semiconductor characteristics and becomes conductive when absorbing light energy such as sunlight (especially ultraviolet light). Examples of such a metal compound include titanium compounds such as TiO 2 , ZnS, and ZnSe.
Metal compounds such as zinc compounds such as cadmium compounds such as CdS and CdTe, and their oxygen, sulfur, selenium or tellurium compounds are typical examples. In particular, in the present invention, an anatase type titanium oxide powder which is inexpensive and also has stain resistance is preferable. The average particle size of the metal compound powder is preferably 0.001 to 30 μm, and particularly preferably 0.1 to 10 μm.
【０００９】光導電性を有する金属化合物粉末は、比表
面積が好ましくは、１〜４００ｍ2／ｇ、特に好ましく
は４〜３５０ｍ2 ／ｇが適当である。金属化合物粉末の
配合量は、塗料固形分中、５〜８０重量％、好ましくは
１０〜６０重量％が適当である。粉末の量が前記範囲よ
り少ないと、その添加効果が不十分となり、一方、多過
ぎると塗膜強度が悪くなるので好ましくない。次に本発
明の鋼材の防食方法について説明する。図１は、本発明
の代表的な電気防食処理を施した鋼材の側断面図であ
り、この図に基づき、本発明の防食方法について説明す
る。鋼材１の表面を必要に応じて通常の前処理を施した
後、プライマー、防食塗料等を塗装して、通常１００〜
３００μm の膜厚の防食塗膜２を形成する。なお、防食
塗膜２は、本発明では必須の構成ではなく、使用しなく
てもよい。また、防食塗膜２としては、既に塗装された
旧塗膜であってもよい。The metal compound powder having photoconductivity preferably has a specific surface area of preferably from 1 to 400 m 2 / g, particularly preferably from 4 to 350 m 2 / g. The compounding amount of the metal compound powder is suitably from 5 to 80% by weight, preferably from 10 to 60% by weight, based on the solid content of the paint. If the amount of the powder is less than the above range, the effect of the addition becomes insufficient, while if it is too large, the strength of the coating film is deteriorated, which is not preferable. Next, the method for preventing corrosion of steel according to the present invention will be described. FIG. 1 is a side sectional view of a steel material subjected to a typical anticorrosion treatment of the present invention, and the anticorrosion method of the present invention will be described with reference to FIG. After subjecting the surface of the steel material 1 to normal pretreatment as necessary, a primer, an anticorrosive paint, or the like is applied, and the
An anticorrosion coating film 2 having a thickness of 300 μm is formed. The anticorrosion coating 2 is not an essential component in the present invention, and need not be used. Further, the anticorrosion coating film 2 may be an old coating film that has already been painted.
【００１０】このような塗装又は未塗装の鋼材表面に前
述の導電性塗膜を形成する塗料あるいは親水性塗膜を形
成する塗料を塗装し、導電性又は親水性塗膜３を形成す
る。該塗膜３の膜厚（乾燥後）は、特に制限はないが、
塗装された鋼材に対しては通常５〜５０μm 、好ましく
は１０〜４０μm 、塗装されてない鋼材に対しては、鋼
材の保護を兼ねて通常５０〜２００μm 、好ましくは７
０〜１５０μm が適当である。次いで、このようにして
形成された導電性又は親水性塗膜３上に陽極板４を積層
させる。陽極板４の固定方法は、例えば、ボルトなどに
よる従来の方法により固定する。陽極板４は、長期耐久
性を必要とするので、大気中において風雨にさらされて
も溶けにくく、かつ電気を流す都合上、導電性の材料で
あり、具体的には、白金や、黒鉛、鋳鉄、アルミニウム
合金等が適当である。The above-mentioned paint for forming the conductive coating or the paint for forming the hydrophilic coating is applied to the surface of the coated or unpainted steel material to form the conductive or hydrophilic coating 3. The thickness (after drying) of the coating film 3 is not particularly limited,
Usually, 5 to 50 μm, preferably 10 to 40 μm for painted steel, and usually 50 to 200 μm, preferably 7 for unpainted steel to protect the steel.
0 to 150 μm is appropriate. Next, the anode plate 4 is laminated on the conductive or hydrophilic coating film 3 thus formed. The fixing method of the anode plate 4 is, for example, a conventional method using bolts or the like. Since the anode plate 4 needs long-term durability, the anode plate 4 is hardly melted even when exposed to wind and rain in the air, and is a conductive material for the purpose of flowing electricity. Specifically, platinum, graphite, Cast iron, aluminum alloy and the like are suitable.
【００１１】このように形成された陽極板４と鋼板１と
を、表面を、例えば、絶縁被覆した銅線等のリード線６
で電源５を介して接続する。陽極板４と鋼材１との間
に、電源より直流電圧を加えることにより防食電流を流
し、鋼材１の腐食を防止するものである。前記直流電圧
は、通常、５〜２０Ｖ、好ましくは１０〜１５Ｖが適当
である。直流電圧が前記範囲より小さいと十分な防食電
流が流れにくく、防食効果が小さくなり、逆に大きいと
陽極板の消耗が生じ易くなる傾向にある。本発明の方法
により、陽極板４、導電性又は親水性塗膜３及び鋼材１
の間に防食電流が流れ、腐食を防止する。なお、この場
合、鋼材が塗装されている場合は、その塗膜自体が導電
性である時は、その塗膜を経由して、また塗膜自体が絶
縁性である時は塗膜のピンホール部あるいは損傷部を経
由して防食電流が流れ、腐食を防止する。The anode plate 4 and the steel plate 1 thus formed are connected to a lead wire 6 such as a copper wire whose surface is coated with an insulating material, for example.
To connect via the power supply 5. The anticorrosion current flows between the anode plate 4 and the steel material 1 by applying a DC voltage from a power supply to prevent corrosion of the steel material 1. The DC voltage is usually 5 to 20 V, preferably 10 to 15 V. If the DC voltage is smaller than the above range, a sufficient anticorrosion current does not easily flow, and the anticorrosion effect is reduced. Conversely, if the DC voltage is higher, the anode plate tends to be consumed. According to the method of the present invention, the anode plate 4, the conductive or hydrophilic coating 3, and the steel 1
During that time, anti-corrosion current flows to prevent corrosion. In this case, when the steel material is coated, the coating film itself is conductive, if the coating film itself is conductive, and if the coating film itself is insulating, the pinhole of the coating film. Corrosion prevention current flows through the part or damaged part to prevent corrosion.
【００１２】[0012]
【実施例】以下、本発明について実施例により、更に詳
細に説明する。実施例１ １×５０×１０００（mm）の磨き軟鋼板にエポキシ樹脂
塗料を乾燥膜厚１００μm になるように塗布し、２４時
間乾燥させた塗膜の表面のみに、ポリアニリン樹脂（Al
lied-Signal 社製、商品名VERSICON) の２０％Ｎ−メチ
ルピロリドン溶液に、光導電性を有するDegussa 社製の
アナターゼ型酸化チタン粉末「Ｐ−２５」（平均比表面
積８０ｍ2 ／ｇ）を塗料固形分中５０重量％になるよう
に加え、分散、混合した塗料を乾燥膜厚３０μm となる
ように塗布し、以下の表１に示す表面抵抗値を有する導
電性塗膜を形成し、裏面及び側面をエポキシ樹脂でシー
ルし、７日間常温で乾燥させた。次いで、表面の端に、
３×５０×５０（mm）の大きさのアルミニウム製陽極板
を張り付けた。更に、そこから８００mm離れた位置に直
径１mmのドリルで素地に達する塗膜欠陥を作った。最後
に、前記陽極板と軟鋼板との間を図１に示すように電源
を介してリード線を接続し、１０Ｖの電圧をかけ、その
状態で１２ケ月間屋外暴露した。暴露後の塗膜欠陥部の
電位、外観は表１に示す通りであった。実施例２ アナターゼ型酸化チタン粉末の添加量が２０重量％であ
る以外は実施例１と同様に試験片を調製し、同様に試験
を行った。結果は表１に示す通りであった。実施例３ 攪拌器を付けた２リットルの三つ口フラフコにイソプロ
ピルアルコール１０００ｇを入れ、７０℃に加温し、ア
ゾビスイソブチロニトリル５ｇを添加した後、アクリル
酸１７５ｇ、２−ヒドロキシエチルメタクリレート７５
ｇ、メチルメタクリレート２００ｇ及びスチレン５０ｇ
からなるモノマー混合物を３時間かけて滴下し、更に、
３時間重合を続けて、アクリル樹脂溶液を得た。これに
アンモニアをアクリル樹脂溶液のpHが7.５になるように
添加し、更に１０００ｇの水を少しずつ滴下して、加熱
残分１９重量％、樹脂固形分当り水酸基価６５mgＫＯＨ
／ｇ、酸価２７３mgＫＯＨ／ｇの水溶性アクリル樹脂組
成物（Ａ）を得た。上記水溶性アクリル樹脂組成物
（Ａ）に、塗料固形分中微細ヒュームドシリカ（日本ア
エロジル社製商品名アエロジル２００）を２重量％、実
施例１と同一のアナターゼ型酸化チタン粉末を５５重量
％となるよう分散、混合した塗料を用い、実施例１と同
様試験片を調製、試験に供した結果は表１に示す通りで
あった。EXAMPLES Hereinafter, the present invention will be described in more detail with reference to Examples. Example 1 An epoxy resin paint was applied to a 1 × 50 × 1000 (mm) polished mild steel sheet so as to have a dry film thickness of 100 μm, and was dried for 24 hours.
lied-Signal Inc., a 20% N-methylpyrrolidone solution of trade name Versicon), Degussa Co. of anatase type titanium oxide powder "P-25" having a photoconductive (average specific surface area 80 m 2 / g) paint The paint was added so as to be 50% by weight in the solid content, dispersed and mixed, and applied to a dry film thickness of 30 μm to form a conductive coating film having a surface resistance value shown in Table 1 below. The sides were sealed with epoxy resin and dried at room temperature for 7 days. Then, at the edge of the surface,
An aluminum anode plate having a size of 3 × 50 × 50 (mm) was attached. Further, a coating defect reaching the substrate was formed at a position 800 mm away therefrom with a drill having a diameter of 1 mm. Finally, a lead wire was connected between the anode plate and the mild steel plate via a power source as shown in FIG. 1, a voltage of 10 V was applied, and exposed outdoors for 12 months in this state. The potential and appearance of the coating defect after exposure were as shown in Table 1. Example 2 A test piece was prepared and tested in the same manner as in Example 1 except that the amount of the anatase type titanium oxide powder was 20% by weight. The results were as shown in Table 1. Example 3 1000 g of isopropyl alcohol was placed in a two-liter three-necked fluffco equipped with a stirrer, heated to 70 ° C., and 5 g of azobisisobutyronitrile was added. Then, 175 g of acrylic acid and 2-hydroxyethyl methacrylate were added. 75
g, methyl methacrylate 200 g and styrene 50 g
Is dropped over 3 hours, and further,
The polymerization was continued for 3 hours to obtain an acrylic resin solution. Ammonia was added to the mixture so that the pH of the acrylic resin solution became 7.5, and 1000 g of water was added dropwise little by little. The heating residue was 19% by weight, and the hydroxyl value per resin solid content was 65 mg KOH.
/ G, a water-soluble acrylic resin composition (A) having an acid value of 273 mgKOH / g. 2% by weight of fine fumed silica (Aerosil 200 manufactured by Nippon Aerosil Co., Ltd.) in the solid content of the water-soluble acrylic resin composition (A), and 55% by weight of the same anatase type titanium oxide powder as in Example 1 A test piece was prepared and subjected to a test in the same manner as in Example 1 using the paint dispersed and mixed so that the results were as shown in Table 1.
【００１３】比較例１ 実施例１と同様にして、磨き軟鋼板にエポキシ樹脂塗料
を厚さ（乾燥後）２００μm になるように塗布し、７日
間常温で乾燥させた後、塗膜欠陥を作り、６ヶ月間屋外
暴露し、暴露後の塗膜欠陥部の電位及び外観を調べた。
結果を以下の表１に示した。比較例２ 実施例１において、アナターゼ型酸化チタン粉末を含有
しない導電性塗膜を形成する以外は、同様に調製した試
験片により同様に試験を行った結果は表１に示す通りで
あった。 Comparative Example 1 In the same manner as in Example 1, an epoxy resin paint was applied to a polished mild steel sheet so as to have a thickness (after drying) of 200 μm and dried at room temperature for 7 days. The film was exposed outdoors for 6 months, and the potential and appearance of the coating film defect after the exposure were examined.
The results are shown in Table 1 below. Comparative Example 2 The same test was conducted using the test piece prepared in the same manner as in Example 1 except that a conductive coating film containing no anatase-type titanium oxide powder was formed. The results are shown in Table 1.
【００１４】[0014]
【表１】 表 １ 親水性塗膜 導電性塗膜の 塗膜欠陥部の電位 12カ月後の塗膜 の接触角 表面抵抗値 （12ヶ月後／70%RH) 欠陥部の外観 （度） （Ω／cm2 ） [ｍＶ／Ag・ AgCl] 実施例１ ８５ １０5 −８２０ 異状なし 実施例２ ９０ １０5 −８００ 異状なし実施例３ ２８ １０12 −８１０ 異状なし 比較例１ ８５ １０14 −５４０ ６ケ月で著しく さびが発生 比較例２ １０５ １０5 −７８０ 薄くさびが発生 （８ケ月異常 なし） 表１からも明らかなように、本発明の電気防食法である
実施例１、２、３では優れた防食効果が得られた。一
方、従来のエポキシ樹脂塗料を塗装したのみの比較例１
では、短期間で著しくさびが発生し、導電性塗膜でもア
ナターゼ型酸化チタン粉末を含有しない比較例２では、
８ケ月までは有効に機能したが、１２ケ月後に薄いさび
の発生が認められ、電気防食の効果が若干不十分であっ
た。[Table 1] Table 1 Hydrophilic Coating Contact angle of coating film after 12 months of potential at coating film defective part of conductive coating surface resistance value (after 12 months / 70% RH) Appearance of defect part (degree) ( Ω / cm 2 ) [mV / Ag · AgCl] Example 1 85 10 5 -820 No defect Example 2 90 10 5 -800 No defect Example 3 28 10 12 -810 No defect Comparative Example 185 10 14 -540 Rust occurred remarkably in 6 months Comparative Example 2 105 10 5 -780 Thin rust occurred ( no abnormality in 8 months ) As is clear from Table 1, in Examples 1, 2 and 3, which are the cathodic protection method of the present invention. Excellent anticorrosion effect was obtained. On the other hand, Comparative Example 1 in which only a conventional epoxy resin paint was applied
In Comparative Example 2, in which rust is remarkably generated in a short time and the conductive coating film does not contain the anatase type titanium oxide powder,
It worked effectively up to 8 months, but after 12 months thin rust was observed and the effect of cathodic protection was somewhat inadequate.
【００１５】[0015]
【発明の効果】本発明の方法により、大気中に存在する
鋼材に対しても外部電源方式の電気防食が可能であり、
従来の塗装のみによる防食方法と比較して、省工程で、
しかも塗膜欠陥があってもそこからのさびの発生を防ぐ
ことができる。According to the method of the present invention, it is possible to carry out an external power supply type of cathodic protection for steel materials existing in the atmosphere.
Compared with the conventional anti-corrosion method using only painting,
Moreover, even if there is a coating film defect, it is possible to prevent the generation of rust therefrom.
【図１】本発明の方法による代表的な電気防食処理を施
した鋼材の側断面図。FIG. 1 is a side cross-sectional view of a steel material subjected to a typical cathodic protection treatment according to the method of the present invention.
１ 鋼材 ２ 防食塗膜 ３ 導電性又は親水性塗膜 ４ 陽極板 ５ 電源 ６ リード線 Reference Signs List 1 steel material 2 anticorrosion coating film 3 conductive or hydrophilic coating film 4 anode plate 5 power supply 6 lead wire
Claims (6)
表面に、光導電性を有する金属化合物粉末５〜８０重量
％を含み、かつ表面抵抗値が１０7 Ω／cm2以下の導電
性塗膜を形成させ、外部電源方式による電気防食法によ
り防食電流を流すことを特徴とする鋼材の防食方法。1. A coated or unpainted steel material present in the air, comprising 5 to 80% by weight of a metal compound powder having photoconductivity and having a surface resistance of 10 7 Ω / cm 2 or less. An anticorrosion method for steel materials, wherein a coating film is formed and an anticorrosion current is applied by an anticorrosion method using an external power supply system.
ンである請求項１記載の鋼材の防食方法。2. The method according to claim 1, wherein the metal compound is an anatase type titanium oxide.
電性の材料からなる陽極板を積層し、鋼材を陰極とし
て、陽極板と鋼材との間に直流電圧を加えて防食電流を
流す請求項１記載の鋼材の防食方法。3. An anode plate made of a poorly water-soluble and conductive material is laminated on the conductive coating film, and a DC voltage is applied between the anode plate and the steel material using a steel material as a cathode to reduce the anticorrosion current. The method for preventing corrosion of steel material according to claim 1, wherein the steel material is flowed.
表面に、光導電性を有する金属化合物粉末５〜８０重量
％を含み、かつ水に対する接触角が７０度以下の親水性
塗膜を形成させ、外部電源方式による電気防食法により
防食電流を流すことを特徴とする鋼材の防食方法。4. A coated or unpainted steel material in the atmosphere is coated with a hydrophilic coating film containing 5 to 80% by weight of a metal compound powder having photoconductivity and having a contact angle to water of 70 ° or less. A corrosion prevention method for a steel material, wherein the steel is formed and an anticorrosion current is caused to flow by an electrolytic protection method using an external power supply system.
ンである請求項４記載の鋼材の防食方法。5. The method according to claim 4, wherein the metal compound is anatase type titanium oxide.
電性の材料からなる陽極板を積層し、鋼材を陰極とし
て、陽極板と鋼材との間に直流電圧を加えて防食電流を
流す請求項１記載の鋼材の防食方法。6. An anode plate made of a poorly water-soluble and conductive material is laminated on the hydrophilic coating film, and a DC voltage is applied between the anode plate and the steel material using a steel material as a cathode to reduce the anticorrosion current. The method for preventing corrosion of steel material according to claim 1, wherein the steel material is flowed.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04872197A JP3658484B2 (en) | 1997-03-04 | 1997-03-04 | Steel corrosion protection method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP04872197A JP3658484B2 (en) | 1997-03-04 | 1997-03-04 | Steel corrosion protection method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH10244622A true JPH10244622A (en) | 1998-09-14 |
| JP3658484B2 JP3658484B2 (en) | 2005-06-08 |
Family
ID=12811169
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP04872197A Expired - Fee Related JP3658484B2 (en) | 1997-03-04 | 1997-03-04 | Steel corrosion protection method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3658484B2 (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007190896A (en) * | 2005-12-19 | 2007-08-02 | Nisshin Steel Co Ltd | Organic resin-coated steel plate excellent in corrosion resistance after painting |
| JP2012021211A (en) * | 2010-07-16 | 2012-02-02 | Fujimori Kogyo Co Ltd | Anti-corrosion structure |
| JP2014052184A (en) * | 2013-11-01 | 2014-03-20 | Uacj Corp | Aluminum fin material for heat exchanger, and heat exchanger using the same |
| CN112076968A (en) * | 2020-09-18 | 2020-12-15 | 中煤科工开采研究院有限公司 | Manufacturing method of steel plate with high corrosion resistance |
| JP2022147887A (en) * | 2021-03-24 | 2022-10-06 | 東日本旅客鉄道株式会社 | Conductive paint, concrete structure electric protection method using the same, and anode material repair method |
-
1997
- 1997-03-04 JP JP04872197A patent/JP3658484B2/en not_active Expired - Fee Related
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2007190896A (en) * | 2005-12-19 | 2007-08-02 | Nisshin Steel Co Ltd | Organic resin-coated steel plate excellent in corrosion resistance after painting |
| JP2012021211A (en) * | 2010-07-16 | 2012-02-02 | Fujimori Kogyo Co Ltd | Anti-corrosion structure |
| JP2014052184A (en) * | 2013-11-01 | 2014-03-20 | Uacj Corp | Aluminum fin material for heat exchanger, and heat exchanger using the same |
| CN112076968A (en) * | 2020-09-18 | 2020-12-15 | 中煤科工开采研究院有限公司 | Manufacturing method of steel plate with high corrosion resistance |
| JP2022147887A (en) * | 2021-03-24 | 2022-10-06 | 東日本旅客鉄道株式会社 | Conductive paint, concrete structure electric protection method using the same, and anode material repair method |
Also Published As
| Publication number | Publication date |
|---|---|
| JP3658484B2 (en) | 2005-06-08 |
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