JPH10264306A - Workpiece of surface treated steel sheet wherein exposed ground metal is treated for rust prevention, and its rust preventive treating method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a workpiece wherein simple and effective rust preventive treatment is applied to an exposed ground part by working or the like when a surface treated steel sheet is to be worked to make a product, and its treating method. SOLUTION: (1) A workpiece of a surface treated steel sheet, of which an exposed ground metal is treated for rust prevention, is provided wherein an acrylic resin coating applied dry film of 1 to 10 wt.% SiO2 and 0.1 to 10 μm thickness is formed on a ground part exposed by working, or a workpiece of the surface treated steel sheet is provided wherein 0.1 to 1.0 wt.% as Cr amount of hexavalent chromiun compound in addition to SiO2 and 5 to 30 wt.% of one or more kinds of organic corrosion preventive inhibitors are contained in the coating applied dry film. (2) A workpiece of the surface treated steel sheet wherein the exposed ground metal is treated for rust prevention by applying and drying acrylic resin water emulsion paint of which the dry film comes to have the abovementioned composition, is manufactured.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、加工して目的とす
る最終の部品または製品にする際の、切断、打ち抜き、
穴あけ、プレス加工等によって露出した素地部分に防錆
処理を施した、表面処理鋼板の加工品、およびその防錆
処理方法に関するものである。BACKGROUND OF THE INVENTION The present invention relates to cutting, punching, and the like for processing into a desired final part or product.
The present invention relates to a processed product of a surface-treated steel sheet in which a base portion exposed by drilling, pressing or the like is subjected to rust prevention treatment, and a rust prevention treatment method thereof.

【０００２】[0002]

【従来の技術】鋼板を所要形状に加工して、家電製品、
建材、自動車部品などに使用する場合、その表面は防錆
目的および外観を整えるため、塗装やめっきなど何らか
の被覆がおこなわれる。これら表面の被覆は、最終形状
に成形後に、あるいは組み上げた後におこなう方法もあ
る。しかし、あらかじめ表面にめっき、さらにはめっき
の上に塗装を施したいわゆる表面処理鋼板を適用すれ
ば、部品や製品のめっきや塗装にともなう劣悪な作業環
境、個々の部品の十分な被覆や塗装のための効率低下、
塗料の歩留まり、排ガス、廃液の処理などの問題が回避
できる。このような利点のため、表面処理鋼板の活用は
近年急速に進みつつある。2. Description of the Related Art A steel sheet is processed into a required shape to be used in home electric appliances,
When used for building materials, automobile parts, etc., their surfaces are coated with some kind of coating, such as painting or plating, for the purpose of rust prevention and appearance. There is also a method of coating these surfaces after forming them into a final shape or after assembling them. However, if a so-called surface-treated steel sheet is plated on the surface in advance and then painted on the plating, the poor working environment associated with plating and painting of parts and products, sufficient coating and painting of individual parts Due to reduced efficiency,
Problems such as the yield of paint, treatment of exhaust gas and waste liquid can be avoided. Due to such advantages, utilization of surface-treated steel sheets has been rapidly progressing in recent years.

【０００３】家電、建材、自動車などに用いられる表面
処理鋼板には、亜鉛めっき鋼板、亜鉛を主とする合金め
っき鋼板、アルミニウムめっき鋼板、さらにはめっき鋼
板の上に有機樹脂系の塗料を塗布した、いわゆるプレコ
ート鋼板などがある。これらの鋼板は工場にて管理され
た条件下で被覆処理がなされるため、その表面は十分な
耐食性を有する。ところが、部品や中間製品あるいは最
終製品に加工された後の、切断端面や厳しい加工による
表面被覆の損傷などで地鉄が露出した部分は、局所的に
耐食性が劣るため、その部分からの腐食の進行の阻止対
策がこれらの鋼板適用の際の一つの大きな課題になって
いる。[0003] Surface-treated steel sheets used for home appliances, building materials, automobiles, etc. are coated with a zinc-coated steel sheet, a zinc-based alloy-coated steel sheet, an aluminum-plated steel sheet, and an organic resin-based paint on the coated steel sheet. And so-called pre-coated steel sheets. Since these steel sheets are coated under the conditions controlled in the factory, their surfaces have sufficient corrosion resistance. However, after processing into parts, intermediate products, or final products, the exposed part of the ground iron due to damage to the cut end face or surface coating due to severe processing, etc., has poor corrosion resistance locally, so corrosion from that part is not possible. Countermeasures to prevent progress have been one of the major issues when applying these steel sheets.

【０００４】表面処理鋼板の切断端面などの露出した地
鉄に対する防錆用塗料には、ジンクリッチペイントがあ
り、これの塗装により十分な耐食性が得られる。また、
従来より用いられている鉄の防錆用の、油性系塗料やア
ルキド樹脂系の塗料も十分に防錆効果が得られる。[0004] As a rust preventive paint for exposed ground iron such as a cut end face of a surface-treated steel sheet, there is zinc rich paint, and sufficient corrosion resistance can be obtained by painting. Also,
Oil-based paints and alkyd resin-based paints conventionally used for iron rust prevention can also provide a sufficient rust prevention effect.

【０００５】ところが、現実の表面処理鋼板の使用時に
課題になったのは、最終用途となる製品に仕上がった状
態もあるが、鋼板を加工後最終製品に使用されるまでの
中間段階における、より簡便な防錆対策であった。例え
ば、建材として表面処理鋼板を適用する場合、形鋼やパ
ネル材に加工し、最終状態に組み上げるまでの途中の段
階で、現場での野積みなど好ましくない環境下に長期間
放置されることがある。完成品に組み上げられれば、必
要な防錆処理が施されたり、よりよい環境下に置かれる
ので問題はない。しかし、そこに至るまでの放置期間で
の端面の発錆のため、効果的な表面処理鋼板の適用が妨
げられる場合がある。[0005] However, the problem when using the actual surface-treated steel sheet is that the finished product is sometimes used as an end-use product. However, in the intermediate stage after the steel sheet is processed and used for the final product. It was a simple rust prevention measure. For example, when applying a surface-treated steel sheet as a building material, it may be left for a long time in an unfavorable environment, such as on-site stacking, in the middle of processing into a shape steel or panel material and assembling it to the final state is there. If assembled into a finished product, there is no problem because the necessary rust prevention treatment is applied and the product is placed in a better environment. However, rusting of the end surface during the leaving period up to that point may hinder the effective application of the surface-treated steel sheet.

【０００６】板厚が薄い場合、その剪断面は表面皮膜の
流れこみがあって被覆される場合があり、また、たとえ
ば亜鉛メッキ鋼板では亜鉛の犠牲防食作用があるので、
とくに防錆処理なしでも、十分発錆を抑止できることが
多い。しかし、板厚が厚くなると、剪断などによる素地
の露出部分が大きくなり、そこから腐食が始まるので露
出部分の防錆が必要となり、場合によってはこの部分を
十分に補修塗装しなければならない。[0006] When the plate thickness is thin, the shear surface may be covered by the inflow of the surface film, and, for example, in the case of galvanized steel sheet, there is a sacrificial corrosion prevention effect of zinc.
In particular, rust generation can often be sufficiently suppressed without rust prevention treatment. However, when the sheet thickness is increased, the exposed portion of the base material due to shearing or the like becomes large, and corrosion starts from the exposed portion. Therefore, rust prevention of the exposed portion is required. In some cases, this portion must be sufficiently repair-painted.

【０００７】従来の防錆塗料による露出端面や加工の皮
膜欠損部分の補修塗装は、乾燥固化に長時間要すると
か、有機溶剤を用いる塗料であるため溶剤の放散による
作業環境悪化、あるいは仕上がり面がよくない等の問題
がある。しかしこれらの方法は、何よりも多大な工数と
コストがかかり、しかも防錆力が過剰になりがちなので
ある。[0007] Repair coating of the exposed end face and the film defect part of the processing by the conventional rust-preventive paint requires a long time for drying and solidifying, or because the paint uses an organic solvent, the working environment is deteriorated due to the dissipation of the solvent, or the finished surface is deteriorated. There are problems such as not good. However, these methods require a great deal of man-hours and cost, and tend to have excessive rust prevention.

【０００８】表面処理鋼板の加工後露出地鉄部分に対す
る簡便な防錆処理について、脱脂と防錆処理の二行程を
同時におこなうことで工程の低減を図ろうとする方法の
発明が、特公平7-116617号公報に提示されている。これ
はＮｉ錯化合物、キレート化合物、２価以上の金属イオ
ンを含む縮合燐酸化合物、硝酸塩、亜硝酸塩等の防錆皮
膜形成成分を含むアルカリ脱脂液を用いて、スプレー、
浸漬、電解脱脂などの手段により脱脂するものである。
この方法によれば、屋内暴露にて２年間赤錆を発生しな
かったとしている。しかしながら、このような脱脂工程
を主体とする方法では、皮膜の厚さや防錆効果が必ずし
も十分でなく、腐食環境が少し悪くなると防錆効果が不
足しがちである。[0008] The invention of a method for reducing the number of steps by simultaneously performing two steps of degreasing and rust prevention for the simple rust prevention treatment of the exposed ground iron portion after processing of the surface-treated steel sheet is disclosed in Japanese Patent Publication No. No. 116617. This is sprayed using an alkali degreasing solution containing a rust-preventing film-forming component such as a Ni complex compound, a chelate compound, a condensed phosphoric acid compound containing divalent or higher valent metal ions, nitrates and nitrites,
It is degreased by means such as immersion and electrolytic degreasing.
According to this method, red rust did not occur for 2 years in indoor exposure. However, in the method based on such a degreasing step, the thickness of the film and the rust prevention effect are not always sufficient, and the rust prevention effect tends to be insufficient if the corrosive environment is slightly deteriorated.

【０００９】[0009]

【発明が解決しようとする課題】本発明の課題は、表面
処理鋼板の活用の際に問題となる、切断端面や表面被覆
の損傷による地鉄露出部分の防錆に対し、より簡便で効
果的な塗料皮膜を形成させた加工品およびその処理方法
を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to provide a simpler and more effective method for preventing rust on exposed portions of ground iron due to damage to a cut end face or surface coating, which is a problem when utilizing a surface-treated steel sheet. It is an object of the present invention to provide a processed article having a coating film formed thereon and a processing method therefor.

【００１０】[0010]

【課題を解決するための手段】本発明者らは、主として
建材用途の表面処理鋼板の地鉄露出部分の防錆のため
の、作業のしやすさ、すぐれた防錆効果、溶剤放散の問
題、等に対処できる塗料や方法について種々検討をおこ
なった。従来、このような防錆用塗料には有機溶剤が用
いられるが、乾燥の際の溶剤の放散が環境を悪くするこ
とや、より安価に処理できることから、水を分散媒とす
るエマルジョン塗料の活用を検討した。水性塗料の場
合、有機溶剤を用いる塗料に比し、乾燥に時間がかか
る。しかし、表面処理鋼板が最終的に使用される前の中
間加工の段階では、洗浄および加熱乾燥をおこなうこと
もあり、また、ある程度の量がまとまれば、別途設備を
用意し加工品への塗料塗布および加熱乾燥は実施可能と
考えられた。Means for Solving the Problems The present inventors have problems in ease of work, excellent rust prevention effect, and solvent diffusion, mainly for the purpose of rust prevention of the exposed portion of the ground steel of the surface-treated steel sheet for building materials. Various studies were made on paints and methods that can cope with such problems. Conventionally, organic solvents have been used for such rust preventive paints. However, the use of emulsion paints using water as a dispersion medium has been widely used since the solvent emission during drying deteriorates the environment and can be processed at lower cost. It was investigated. In the case of a water-based paint, it takes longer to dry than a paint using an organic solvent. However, in the intermediate processing stage before the surface-treated steel sheet is finally used, washing and heating and drying may be performed.If a certain amount is collected, separate equipment must be prepared to apply paint to the processed product. And heat drying was considered feasible.

【００１１】塗料のベースとなる樹脂の選択に際し、ア
クリル系、アクリルスチレン系、アクリルシリコン系、
ポリエステル系、アルキド系およびウレタン系を比較し
た。その結果、アクリルスチレン系とポリエステル系
は、耐アルカリ性および耐候性が不十分であり、アルキ
ド系は耐アルカリ性が良くなく、ウレタン系は水に何か
添加するとエマルジョンが不安定になりがちである。こ
れらに比較して、アクリル系は樹脂の耐候性がよく、耐
アルカリ性、耐酸性もすぐれており、本発明の目的とす
る塗料のベース樹脂として最も好ましいことがわかっ
た。In selecting a resin as a base material of a paint, an acrylic resin, an acrylic styrene resin, an acrylic silicon resin,
Polyester, alkyd and urethane were compared. As a result, the acrylic styrene type and the polyester type are insufficient in alkali resistance and weather resistance, the alkyd type is not good in alkali resistance, and the urethane type tends to be unstable when added to water. Compared with these, the acrylic resin has better weather resistance, excellent alkali resistance and acid resistance, and was found to be the most preferable as the base resin of the paint intended for the present invention.

【００１２】防錆処理を必要とする部分は、鋼板の切断
部や強加工部分であり、この部分は周辺から突起した状
態となることが多いので、平面に塗布する場合とは異な
る配慮が必要である。これは、一つには塗布皮膜厚さが
不十分になりがちであることと、もう一つには他の物体
が接触する危険が大きいことである。そこでこの対策を
種々検討の結果、塗料を構成するアクリル樹脂の製造工
程において、コロイダルシリカを混合して樹脂を作製
し、これを用いた塗料にすれば、塗布時の厚さ確保が容
易となり、さらに乾燥後の塗膜の硬さが向上して、他の
物体の接触による塗膜の損傷を低減できることがわかっ
た。The parts requiring rust prevention treatment are the cut parts and the strongly processed parts of the steel sheet, and these parts are often protruded from the periphery. It is. This is due to the fact that the coating film thickness tends to be insufficient, and on the other hand, the risk of contact with other objects is great. Therefore, as a result of various investigations on this measure, in the process of manufacturing the acrylic resin that constitutes the paint, if a resin is produced by mixing colloidal silica and the paint is made using this, it is easy to secure the thickness at the time of application, Further, it was found that the hardness of the coating film after drying was improved, and damage to the coating film due to contact with other objects could be reduced.

【００１３】次に、地鉄の露出部を主な対象とするの
で、水性の塗料は塗布後の乾燥が長時間にわたる場合、
発錆の危険性が増す。この対策として、水溶性の防錆剤
の添加を検討した。防錆剤として６価クロム化合物、ま
たは水溶性有機物系の腐食抑制剤の添加を調査した結
果、単に地鉄からの発錆を抑止できるばかりでなく、塗
布した皮膜の防錆効果がより一層向上することを見いだ
したのである。これは、乾燥後も残存する防錆剤の効果
が、皮膜の耐候性や耐酸、耐アルカリ性とあいまって、
防錆処理の効果をより一層高める結果になったためと推
定された。[0013] Next, since the main target is the exposed part of the base iron, the water-based paint is required to be dried for a long time after application.
Increases the risk of rusting. As a countermeasure, the addition of a water-soluble rust inhibitor was studied. Investigation of the addition of a hexavalent chromium compound or a water-soluble organic corrosion inhibitor as a rust preventive agent not only can prevent rust from the ground iron, but also improve the rust preventive effect of the applied film. To find something to do. This is because the effect of the rust inhibitor remaining after drying is combined with the weather resistance, acid resistance and alkali resistance of the film,
It is estimated that the effect of the rust prevention treatment was further enhanced.

【００１４】以上のような知見に基づき、さらに塗料塗
布の限界、塗料の構成や塗布条件等を明らかにし本発明
を完成させた。本発明の要旨は次の通りである。Based on the above findings, the present invention has been completed by further clarifying the limits of paint application, the composition of the paint and the application conditions. The gist of the present invention is as follows.

【００１５】(1) 加工によって露出した素地部分に、Ｓ
ｉＯ₂ 量が 1〜10重量％である膜厚0.1〜10μm のアク
リル樹脂系の塗料塗布乾燥皮膜が形成されていることを
特徴とする、露出地鉄を防錆処理した表面処理鋼板の加
工品。 (2) Ｃｒ量で 0.1〜 1.0重量％の６価クロム化合物およ
び 0.5〜30重量％の有機系腐食抑制剤の１種以上を、塗
料塗布乾燥皮膜中に含有していることを特徴とする、
(1) に記載の露出地鉄を防錆処理した表面処理鋼板の加
工品。(1) S
A processed product of a surface-treated steel sheet having a rust-proofing treatment of exposed ground iron, characterized in that an acrylic resin-based paint-coated and dried film having a thickness of 0.1 to 10 μm and an iO ₂ amount of 1 to 10% by weight is formed. . (2) characterized in that the paint coating contains at least one of a hexavalent chromium compound in an amount of Cr of 0.1 to 1.0% by weight and an organic corrosion inhibitor in an amount of 0.5 to 30% by weight in a paint applied dry film,
A processed product of a surface-treated steel sheet obtained by subjecting the exposed ground iron described in (1) to a rust-proof treatment.

【００１６】(3) 乾燥皮膜中のＳｉＯ₂ 量が 1〜10重量
％となるシリカを含むアクリル樹脂系の水性エマルジョ
ン塗料を、加工した後の地鉄が露出した部分に塗布して
乾燥処理をおこない、膜厚 0.1〜10μm の皮膜を形成さ
せることを特徴とする、(1)に記載の露出地鉄を防錆処
理した表面処理鋼板の加工品の製造方法。(3) An acrylic resin-based aqueous emulsion paint containing silica in which the amount of SiO ₂ in the dry film is 1 to 10% by weight is applied to the exposed portion of the ground iron after processing, and the drying treatment is performed. (1) The method for producing a processed product of a surface-treated steel sheet in which the exposed ground iron is rust-proofed, wherein a film having a thickness of 0.1 to 10 μm is formed.

【００１７】(4) 乾燥皮膜中のＳｉＯ₂ 量が 1〜10重量
％となるシリカを含み、さらに乾燥皮膜中のＣｒ量が
0.1〜 1.0重量％となる６価クロム化合物および乾燥皮
膜中 0.5〜30重量％となる有機系腐食抑制剤の１種以上
を含有するアクリル樹脂系の水性エマルジョン塗料を、
加工した後の地鉄が露出した部分に塗布し乾燥処理をお
こない、膜厚 0.1〜10μm の皮膜を形成させることを特
徴とする、(2) に記載の露出地鉄を防錆処理した表面処
理鋼板の加工品の製造方法。(4) The dry film contains silica in which the amount of SiO ₂ is 1 to 10% by weight, and the amount of Cr in the dry film is
An acrylic resin-based aqueous emulsion paint containing 0.1 to 1.0% by weight of a hexavalent chromium compound and 0.5 to 30% by weight of an organic corrosion inhibitor in a dry film,
The surface treatment according to (2), wherein the exposed surface iron is subjected to a rust-proof treatment by applying to the exposed portion of the exposed surface iron and performing a drying treatment to form a film having a thickness of 0.1 to 10 μm. Manufacturing method of processed steel sheet.

【００１８】なお、ここで塗料というのは、塗布し乾燥
したあと固体の皮膜に変化する、樹脂を主体とした塗膜
形成要素、塗料用顔料、補助材料、および溶剤から構成
された液状のものを示す。乾燥処理というのは、塗料中
の溶剤を蒸発乾燥させる物理的な乾燥だけでなくでな
く、樹脂などの塗膜形成要素が融合したり、結合反応し
て巨大分子化したりして、強固な皮膜を形成していく化
学的な乾燥も含むものである。乾燥処理は室温で放置し
ても良いが、70〜 120℃程度までの水が沸騰しない範囲
の温度で加熱できれば、造膜、すなわち塗膜の形成は短
時間で安定しておこなえる。Here, the paint is a liquid paint composed of a resin-based film-forming element, a paint pigment, an auxiliary material, and a solvent, which changes to a solid film after being applied and dried. Is shown. The drying process is not only a physical drying process in which the solvent in the paint is evaporated and dried, but also a film that fuses with the resin and other film-forming elements or undergoes a bonding reaction to form a macromolecule. This also includes chemical drying to form. The drying treatment may be left at room temperature, but if the heating can be performed at a temperature up to about 70 to 120 ° C. in a range in which water does not boil, film formation, that is, formation of a coating film can be stably performed in a short time.

【００１９】このようにして、加工により露出した地鉄
部分に防錆処理を施した表面処理鋼板の加工品は、その
まま最終製品にも十分適用できるが、健全な表面皮膜が
存在する状態に比較すれば、その地鉄露出部分の耐食性
はやや劣るので、最終の完成品としては、必要に応じさ
らに防錆処理を施してもよい。[0019] The processed product of the surface-treated steel sheet obtained by subjecting the portion of the base iron exposed by the processing to rust-prevention in this way can be sufficiently applied to the final product as it is, but compared with a state in which a sound surface film exists. If this is the case, the corrosion resistance of the exposed portion of the base iron is slightly inferior, so that the final finished product may be subjected to a further rust-proof treatment as necessary.

【００２０】[0020]

【発明の実施の形態】本発明は、亜鉛めっき鋼板、亜鉛
を主とする合金めっき鋼板、アルミニウムめっき鋼板、
さらにはこれらめっき鋼板の上に有機樹脂系の塗料を塗
布したいわゆるプレコート鋼板などの表面処理鋼板の加
工品を対象とする。ただし、表面処理鋼板に限らず、種
々の鋼材の露出素地部分に適用しても効果的である。DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a galvanized steel sheet, a zinc-based alloy-coated steel sheet, an aluminum-coated steel sheet,
Further, the present invention is also directed to a processed product of a surface-treated steel sheet such as a so-called pre-coated steel sheet in which an organic resin-based paint is applied on these plated steel sheets. However, the present invention is not limited to the surface-treated steel sheet, and is effective even when applied to exposed base portions of various steel materials.

【００２１】塗料の塗膜形成要素であるアクリル樹脂
は、通常の水性塗料に用いられるエマルジョン状態のも
のでよく、アクリル系であれば特定の構成の樹脂でなく
ともよい。ただし、樹脂のガラス転移点は25〜55℃であ
ることが望ましく、その酸価は20以下であることが好ま
しい。ガラス転移点は25℃を下回る場合、塗料の皮膜が
柔らかく傷つきやすくなり、塗膜部分が接触した状態で
加工品が重ねて置かれたとき、ブロッキングを起こす危
険性もある。また、55℃を超えると健全な皮膜が形成さ
れ難くなる。樹脂の酸価は、固化した樹脂 1ｇを中和す
るするのに必要な水酸化カリウムのミリグラム数で示さ
れるが、20を超えると皮膜の耐水性、耐アルカリ性、耐
酸性のいずれも低下する傾向があり、結露環境下におい
て、防食効果が低下してくる。望ましい酸価は 2〜10の
範囲である。The acrylic resin, which is a coating film forming element of the paint, may be in an emulsion state used for ordinary water-based paints, and need not be a resin having a specific constitution as long as it is an acrylic resin. However, the glass transition point of the resin is desirably 25 to 55 ° C., and the acid value is desirably 20 or less. When the glass transition point is lower than 25 ° C., the coating film becomes soft and easily damaged, and there is also a risk of blocking when the processed products are placed one on top of the other with the coating film portions in contact. On the other hand, if the temperature exceeds 55 ° C., it is difficult to form a sound film. The acid value of the resin is indicated by the number of milligrams of potassium hydroxide required to neutralize 1 g of the solidified resin.If it exceeds 20, the water resistance, alkali resistance, and acid resistance of the coating tend to decrease. In a dew condensation environment, the anticorrosion effect decreases. Desirable acid numbers are in the range of 2-10.

【００２２】本発明では、乾燥後の皮膜の中に重量％で
1〜10％のＳｉＯ₂ が含有されるよう、シリカを含むア
クリル樹脂のエマルジョンを塗料の塗膜形成要素とす
る。シリカを含むアクリル樹脂は、樹脂の製造工程にお
いてコロイダルシリカを混合して作られる。所要量のシ
リカを含ませたアクリル樹脂のエマルジョンを作製し、
これで塗料を作ってもよく、シリカを含む樹脂と含まな
い樹脂を適宜混合して所要のシリカ量として塗料を作っ
てもよい。シリカは、塗布時の塗料厚さの確保のため
と、乾燥後の塗膜の硬さ向上を目的で含有させるが、 1
重量％未満の含有ではこれらの効果が十分得られず、10
重量％を超えて含有すると、耐アルカリ性が低下してく
る。より望ましいのは、 1.5〜 5重量％の含有である。In the present invention, by weight% in the dried film
An acrylic resin emulsion containing silica is used as a coating film forming element so that 1 to 10% of SiO ₂ is contained. The acrylic resin containing silica is produced by mixing colloidal silica in the resin manufacturing process. Make an acrylic resin emulsion containing the required amount of silica,
This may be used to prepare a paint, or a resin containing silica and a resin not containing silica may be appropriately mixed to prepare a paint having a required amount of silica. Silica is contained for the purpose of securing the paint thickness at the time of application and for improving the hardness of the coating film after drying.
If the content is less than 10% by weight, these effects cannot be sufficiently obtained.
If the content exceeds 10% by weight, the alkali resistance decreases. More desirable is a content of 1.5 to 5% by weight.

【００２３】シリカを含むアクリル樹脂系エマルジョン
を塗膜形成要素とするこの水性塗料に、さらに６価クロ
ム化合物および有機系腐食抑制剤の１種以上を含有させ
ることにより、一層塗料塗布部分の耐食性を向上させる
ことができる。含有させる量は、６価クロム化合物の場
合、Ｃｒ元素の量として乾燥皮膜の 0.1〜 1.0重量％が
好ましい。これは、 0.1％未満ではその効果が十分でな
く、 1.0％を超えると、エマルジョンの不安定、処理し
た加工品の表面の黄変、さらには、乾燥後未反応の残存
６価クロムイオンの溶出、等の問題が生じてくるからで
ある。６価クロム化合物としては、無水クロム酸やクロ
ム酸アンモニウムなどの不揮発性のアルカリ成分を含ま
ない化合物が好ましいが、重クロム酸カリウム、クロム
酸カルシウム、クロム酸亜鉛、クロム酸ストロンチウム
などでもよい。The aqueous coating composition containing an acrylic resin-based emulsion containing silica as a coating film-forming element further contains at least one of a hexavalent chromium compound and an organic corrosion inhibitor to further improve the corrosion resistance of the coating-coated portion. Can be improved. In the case of a hexavalent chromium compound, the amount to be contained is preferably 0.1 to 1.0% by weight of the dry film as the amount of Cr element. If the content is less than 0.1%, the effect is not sufficient, and if it exceeds 1.0%, the emulsion becomes unstable, the surface of the processed product yellows, and the elution of unreacted residual hexavalent chromium ions after drying. This is because problems such as As the hexavalent chromium compound, a compound containing no non-volatile alkali component such as chromic anhydride and ammonium chromate is preferable, but potassium dichromate, calcium chromate, zinc chromate, strontium chromate and the like may be used.

【００２４】有機系腐食抑制剤は、有機インヒビターと
も呼ばれる、金属の腐食抑制に有効であることが知られ
ている有機化合物である。化合物の例としては、ベンゾ
イミダゾール、ベンゾトリアゾール、ベンゾチアゾー
ル、ジメルカプトチアゾール、メルカプトベンゾチアゾ
ール、ベンゾイソチアゾール、オクチン、ラウリルアミ
ン、クエン酸アンモニウム等がある。含有させる量は乾
燥後の皮膜中に 0.5〜30重量％の範囲であることとす
る。これは、 0.5％未満では添加の効果が現れず、30％
を超えるようになると硬さ低下や欠陥発生を来し、皮膜
の健全性が失われるためである。皮膜の健全性に影響な
く十分に効果を発揮するのに望ましい量は、1.0〜 5.0
％である。The organic corrosion inhibitor is an organic compound which is also known as an organic inhibitor and is known to be effective for inhibiting metal corrosion. Examples of compounds include benzimidazole, benzotriazole, benzothiazole, dimercaptothiazole, mercaptobenzothiazole, benzoisothiazole, octin, laurylamine, ammonium citrate and the like. The amount to be contained is in the range of 0.5 to 30% by weight in the dried film. This is because the effect of addition does not appear at less than 0.5%,
If the hardness exceeds the above range, the hardness will decrease or defects will occur, and the soundness of the film will be lost. The desired amount to achieve full effect without affecting the soundness of the coating is 1.0-5.0
%.

【００２５】これらを皮膜中に含有させる場合、６価ク
ロム化合物のみの１種以上、または有機系腐食抑制剤の
みの１種以上でもよく、６価クロム化合物の１種以上と
有機系腐食抑制剤の１種とを同時に含有させてもよい。
上記範囲内であればそれらの含有量に応じて塗膜部分の
耐食性を向上させることができる。When these are contained in the film, one or more hexavalent chromium compounds alone or one or more organic corrosion inhibitors alone may be used, and one or more hexavalent chromium compounds and an organic corrosion inhibitor may be used. May be simultaneously contained.
When the content is within the above range, the corrosion resistance of the coating film portion can be improved according to their contents.

【００２６】その他、造膜助剤、界面活性剤、増粘剤、
顔料、染料等、塗料として必要な補助的添加物に関して
は、通常の塗料の場合と同じように必要に応じて適宜添
加すればよく、とくには限定しない。なお、造膜助剤
は、ブチルセルソルブ、ブチルカルビトールなどの親水
性エーテル類や、アジピン酸ジメチル、グルタル酸ジメ
チルなどの二塩基酸エステル類を用いればよい。水性塗
料の場合、乾燥温度を70〜 120℃の比較的低温に留める
方が望ましいので、造膜促進のため造膜助剤は多めに添
加し、乾燥皮膜に対し 1〜10重量％分含有させることが
好ましい。塗膜のピンホール発生を抑止するために、乾
燥皮膜に対し0.01〜 0.1重量％程度の界面活性剤の添加
が好ましく、耐食性劣化の少ないフッ素系ノニオン界面
活性剤がよい。In addition, a film-forming auxiliary, a surfactant, a thickener,
Auxiliary additives, such as pigments and dyes, required as a paint may be appropriately added as needed, as in the case of ordinary paints, and are not particularly limited. As the film-forming aid, hydrophilic ethers such as butyl cellosolve and butyl carbitol, and dibasic acid esters such as dimethyl adipate and dimethyl glutarate may be used. In the case of water-based paints, it is desirable to keep the drying temperature at a relatively low temperature of 70 to 120 ° C. Therefore, a large amount of a film-forming aid is added to promote film formation, and 1 to 10% by weight of the dry film is contained. Is preferred. In order to suppress the occurrence of pinholes in the coating film, it is preferable to add a surfactant in an amount of about 0.01 to 0.1% by weight based on the dry film, and a fluorine-based nonionic surfactant having little deterioration in corrosion resistance is preferable.

【００２７】以上のように、シリカを含むアクリル樹脂
系の水性エマルジョン塗料をベースに、６価クロム化合
物または有機系腐食抑制剤を添加して改善した塗料を、
表面処理鋼板の加工により生じた地鉄の露出部分に塗布
するが、塗布する膜厚は、乾燥後において、 0.1〜10μ
m とする。これは、 0.1μm 未満の厚さでは防食効果が
不十分であり、10μm を超える厚さになると、効果が飽
和してくるばかりでなく、塗膜に気泡等の欠陥を生じや
すくなり、コストも上がってくる。よりすぐれた防食効
果が得られ、また、作業が容易でコスト的にも合理的な
点で望ましい乾燥後皮膜厚さは 0.5〜 5μm である。As described above, a paint improved by adding a hexavalent chromium compound or an organic corrosion inhibitor based on an acrylic resin-based aqueous emulsion paint containing silica,
It is applied to the exposed part of the ground iron generated by processing the surface-treated steel sheet.
m. If the thickness is less than 0.1 μm, the anticorrosion effect is insufficient.If the thickness exceeds 10 μm, not only the effect is saturated, but also the coating film tends to have defects such as air bubbles, and costs are reduced. Come up. The preferred thickness of the film after drying is 0.5 to 5 μm in that a better anticorrosion effect is obtained, and the work is easy and the cost is reasonable.

【００２８】塗料を素地露出部分に塗布する方法は、目
的とする被塗装部分に所要の皮膜厚さを塗布できるので
あれば何でもよく、刷毛塗り、スプレイ塗布、ディッピ
ング等一般に用いられる方法でおこなえばよい。塗膜は
加工品の露出地金部に限定して塗装できるのであれば望
ましいが、露出地金部が所定の乾燥皮膜厚さで被覆され
ておれば、メッキなど鋼板の表面皮膜が存在する他の部
分も同時に塗膜に覆われてもかまわない。塗布後は放置
による自然乾燥でもよく、可能なら70〜 120℃の温度に
加熱すれば、安定した防錆力のある皮膜をより速やかに
形成させることができる。加熱温度が70℃未満では、乾
燥に時間がかかり、 120℃を超えると、水が沸騰して塗
膜の欠陥が生じたり、鋼板に処理されている表面皮膜を
傷めることがある。The method of applying the paint to the exposed portion of the substrate is not particularly limited as long as the desired coating thickness can be applied to the target portion to be coated, and may be applied by a commonly used method such as brush coating, spray coating, dipping, or the like. Good. It is desirable if the coating can be applied only to the exposed metal part of the processed product, but if the exposed metal part is coated with a predetermined dry film thickness, the surface coating of the steel sheet such as plating may be present. May be covered with the coating film at the same time. After the coating, the coating may be left to dry naturally, and if possible, if heated to a temperature of 70 to 120 ° C., a stable and rust-proof coating can be formed more quickly. If the heating temperature is lower than 70 ° C., it takes a long time to dry. If the heating temperature is higher than 120 ° C., water may be boiled to cause defects in the coating film or damage the surface coating applied to the steel sheet.

【００２９】[0029]

【実施例】板厚 1mmの、冷延鋼板、溶融亜鉛めっき鋼板
（目付量：120 g/m²）、合金化溶融亜鉛めっき鋼板（目
付量：120 g/m²）、Ａｌ− 9％Ｓｉめっき鋼板（目付
量：40g/m²）、Ａｌ−25％Ｍｎめっき鋼板（目付量：20
g/m²）、Ｚｎ−55％Ａｌめっき鋼板（目付量：75g/
m²）、Ｚｎ− 5％Ａｌめっき鋼板（目付量：90g/m²）、
を用い、これらから、幅30mm、長さ150mmの試験片を切
り出した。この試験片に、シリカ含むアクリル系エマル
ジョン水性塗料をベースとし、これに６価クロム化合物
として無水クロム酸、有機系腐食抑制剤としてベンゾト
リアゾール等の含有量を種々変えた塗料を用意して、浸
漬法により塗布した。膜厚は、増粘剤の添加、および塗
膜形成要素の濃度を変えることによって調整した。塗布
後の試験片は、乾燥条件を揃えるため、 120℃に加熱し
たオーブンの中に投入し、 5分間保持して乾燥させた。
これらの塗料の添加物組成および膜厚を表１に示す。[Example] Cold rolled steel sheet, hot-dip galvanized steel sheet (basis weight: 120 g / m ² ), alloyed hot-dip galvanized steel sheet (basis weight: 120 g / m ² ), thickness of 1 mm, Al-9% Si Coated steel sheet (weight: 40 g / m ² ), Al-25% Mn plated steel sheet (weight: 20
g / m ² ), Zn-55% Al-plated steel sheet (basis weight: 75 g /
m ² ), Zn-5% Al-plated steel sheet (basis weight: 90 g / m ² ),
, And a test piece having a width of 30 mm and a length of 150 mm was cut out from these. This test piece was prepared by immersing a paint based on an acrylic emulsion aqueous paint containing silica, in which chromic anhydride as a hexavalent chromium compound and benzotriazole as an organic corrosion inhibitor were variously changed. It was applied by a method. The film thickness was adjusted by adding a thickener and changing the concentration of the film forming element. The test piece after application was placed in an oven heated to 120 ° C. and dried for 5 minutes to make the drying conditions uniform.
Table 1 shows the additive composition and film thickness of these paints.

【００３０】[0030]

【表１】 [Table 1]

【００３１】得られた塗布後試験片の塗膜について、欠
陥の有無、塗膜の硬さなどを調査し、クロム化合物を添
加した塗料の場合は、６価クロムの溶出量を測定した。
耐酸性は 0.5％ＨＣｌ水溶液に、耐アルカリ性は 0.5％
ＮａＯＨ水溶液に、いずれも20℃にて30分間浸漬し、塗
膜下の地鉄露出部分における黒変の有無を観察した。耐
食性については、塗料に浸漬して端面部も塗布皮膜で覆
われた上記寸法の試験片を、同一場所にて１ヶ月間屋外
に暴露した後、赤錆の発生を目視観察した。この場合冷
延鋼板は、塗料を塗布した平面部、他のメッキ鋼板の場
合は、切断した端面部を評価対象とした。The coating film of the obtained test piece after coating was examined for the presence or absence of defects, hardness of the coating film, and the like, and in the case of a coating material containing a chromium compound, the elution amount of hexavalent chromium was measured.
Acid resistance 0.5% HCl aqueous solution, alkali resistance 0.5%
Each was immersed in a NaOH aqueous solution at 20 ° C. for 30 minutes, and the presence or absence of blackening in the exposed part of the base iron under the coating was observed. Regarding the corrosion resistance, a test piece of the above dimensions, which was immersed in a paint and the end face was also covered with the coating film, was exposed outdoors at the same place for one month, and then the occurrence of red rust was visually observed. In this case, the cold rolled steel sheet was evaluated on a flat surface portion coated with a paint, and in the case of another plated steel sheet, a cut end face portion was evaluated.

【００３２】[0032]

【発明の効果】本発明は、表面処理鋼板を用いた建材そ
の他の中間品や製品に成形した、加工による露出地鉄部
分の耐食性の良好な加工品を提供するものである。本発
明を適用すれば、従来より問題であった表面処理鋼板の
露出地鉄部分の防食処理を簡便な方法でおこなうことに
より十分な耐食性が得られ、表面処理鋼板の用途を拡大
することができる。According to the present invention, there is provided a processed product which is formed into a building material or other intermediate product or product using a surface-treated steel sheet and has good corrosion resistance of an exposed part of a ground iron by processing. If the present invention is applied, sufficient corrosion resistance can be obtained by performing the anticorrosion treatment of the exposed ground iron portion of the surface-treated steel sheet, which has been a problem in the past, by a simple method, and the use of the surface-treated steel sheet can be expanded. .

Claims (4)

【特許請求の範囲】[Claims] 【請求項１】加工によって露出した素地部分に、ＳｉＯ
₂ 量が 1〜10重量％である膜厚 0.1〜10μm のアクリル
樹脂系の塗料塗布乾燥皮膜が形成されていることを特徴
とする、露出地鉄を防錆処理した表面処理鋼板の加工
品。A substrate portion exposed by processing is provided with SiO 2
_2. A processed product of a surface-treated steel sheet in which an exposed ground iron is rust-proofed, wherein an acrylic resin-based paint-coated dry film having a thickness of 0.1 to 10 μm and a thickness of 1 to 10% by weight is formed. 【請求項２】Ｃｒ量で 0.1〜 1.0重量％の６価クロム化
合物および 0.5〜30重量％の有機系腐食抑制剤の１種以
上を、塗料塗布乾燥皮膜中に含有していることを特徴と
する、請求項１に記載の露出地鉄を防錆処理した表面処
理鋼板の加工品。2. A paint-coated dry film containing at least one of a hexavalent chromium compound having a Cr content of 0.1 to 1.0% by weight and an organic corrosion inhibitor having a Cr content of 0.5 to 30% by weight. A processed product of a surface-treated steel sheet obtained by subjecting the exposed ground iron according to claim 1 to rust prevention treatment. 【請求項３】乾燥皮膜中のＳｉＯ₂ 量が 1〜10重量％と
なるシリカを含むアクリル樹脂系の水性エマルジョン塗
料を、加工した後の地鉄が露出した部分に塗布して乾燥
処理をおこない、膜厚 0.1〜10μm の皮膜を形成させる
ことを特徴とする、請求項１に記載の露出地鉄を防錆処
理した表面処理鋼板の加工品の製造方法。3. An acrylic resin-based aqueous emulsion paint containing silica in which the amount of SiO ₂ in the dry film is 1 to 10% by weight is applied to a portion where the ground iron is exposed after processing, and a drying treatment is performed. 2. The method for producing a processed product of a surface-treated steel sheet having a rust-proofed surface of an exposed ground iron according to claim 1, wherein a film having a thickness of 0.1 to 10 [mu] m is formed. 【請求項４】乾燥皮膜中のＳｉＯ₂ 量が 1〜10重量％と
なるシリカを含み、さらに乾燥皮膜中のＣｒ量が 0.1〜
1.0重量％となる６価クロム化合物および乾燥皮膜中
0.5〜30重量％となる有機系腐食抑制剤の１種以上を含
有するアクリル樹脂系の水性エマルジョン塗料を、加工
した後の地鉄が露出した部分に塗布し乾燥処理をおこな
い、膜厚 0.1〜10μm の皮膜を形成させることを特徴と
する、請求項２に記載の露出地鉄を防錆処理した表面処
理鋼板の加工品の製造方法。4. A method according to claim 1, wherein the dry film contains silica in which the content of SiO ₂ is 1 to 10% by weight, and the content of Cr in the dry film is 0.1 to 10 wt%
Hexavalent chromium compound to be 1.0% by weight and in dry film
An acrylic resin-based aqueous emulsion paint containing at least one kind of organic corrosion inhibitor of 0.5 to 30% by weight is applied to the exposed part of the ground iron after processing and dried, and the film thickness is 0.1 to 30%. 3. The method according to claim 2, wherein a film having a thickness of 10 μm is formed.