JP5061978B2 - Surface-treated steel sheets and coated steel plates with excellent corrosion resistance, heat radiation, and conductivity - Google Patents
Surface-treated steel sheets and coated steel plates with excellent corrosion resistance, heat radiation, and conductivity Download PDFInfo
- Publication number
- JP5061978B2 JP5061978B2 JP2008069774A JP2008069774A JP5061978B2 JP 5061978 B2 JP5061978 B2 JP 5061978B2 JP 2008069774 A JP2008069774 A JP 2008069774A JP 2008069774 A JP2008069774 A JP 2008069774A JP 5061978 B2 JP5061978 B2 JP 5061978B2
- Authority
- JP
- Japan
- Prior art keywords
- chemical conversion
- steel sheet
- layer
- heat
- 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.)
- Active
Links
Images
Landscapes
- Laminated Bodies (AREA)
- Chemical Treatment Of Metals (AREA)
Description
本発明は、内部で熱および／または電磁波を生じる家電製品、パソコンといった電気・電子製品の筐体、ならびに放熱板に好適な表面処理鋼板および塗装鋼板に関する。本発明において、筐体とは、製品またはその内部部品を収容する箱状体を意味する。 The present invention relates to a surface-treated steel sheet and a coated steel sheet suitable for a housing of an electric / electronic product such as a household electric appliance or a personal computer that generates heat and / or electromagnetic waves inside, and a heat sink. In the present invention, the housing means a box-like body that houses a product or its internal components.
炭酸ガスによる地球温暖化を防止する観点から、産業用、生活関連用を問わず、あらゆる電気・電子機器類の省エネルギー化が進められている。例えば、エアコンでは、室内機や室外機のラジエーターの大型化や風量の増大等により省エネルギー化が図られている。 From the viewpoint of preventing global warming due to carbon dioxide gas, energy saving is being promoted for all electrical and electronic devices, whether industrial or life related. For example, in an air conditioner, energy saving is achieved by increasing the size of a radiator of an indoor unit or an outdoor unit or increasing the air volume.
冷蔵庫やパソコン等でも、特に近年、冷蔵庫の大型化やパソコンの演算速度の向上により、圧縮機やＣＰＵ（中央処理装置）からの発熱量が増大する傾向にあり、内部で生じる熱を速やかに外部に放散させることが求められている。 Even in refrigerators and personal computers, the amount of heat generated from compressors and CPUs (central processing units) tends to increase due to the recent increase in size of refrigerators and the increase in computing speed of personal computers. It is required to dissipate.
冷蔵庫の場合、圧縮機で生じた熱の放散には放熱器が用いられ、エアコンのようなファンによる強制対流は行われない。放熱器は、従来は外部の空気と直接接し、圧縮機で生じた熱は放熱器から直接外部空気へ放散されていた。しかし、意匠性の観点から、現在では放熱器のほとんどが内部に格納された形式のものとなっており、内部で発生した熱は、圧縮機→放熱器→放熱板の順に伝わって放熱板から放散される。したがって、現在の冷蔵庫は、従来のものに比べ、放熱しにくい構造となっている。 In the case of a refrigerator, a radiator is used to dissipate the heat generated by the compressor, and forced convection by a fan such as an air conditioner is not performed. Conventionally, the radiator is in direct contact with the external air, and the heat generated by the compressor is directly dissipated from the radiator to the external air. However, from the viewpoint of design, most of the heatsinks are currently stored inside, and the heat generated inside is transferred from the heatsink in the order of compressor → heatsink → heatsink. Dissipated. Therefore, current refrigerators have a structure that is less likely to dissipate heat than conventional ones.
放熱板からの熱の放散（すなわち、外部空気への伝熱）は、対流と放射による。このうち、対流の影響は小さい。これは、冷蔵庫が屋内で使用されること、また、通常は放熱板が取り付けられている裏面が壁に近接して使用されることから、空気の移動（流れ）が小さい自然対流伝熱となる。そのため、放熱板からの熱の放散では、放射による伝熱の寄与が大きい。したがって、放熱板の放熱性が優れていると、冷蔵庫全体としての熱交換効率が向上して消費電力が低減する。また、部品や冷蔵庫の寿命の延長にもつながる。 Heat dissipation from the heat sink (ie heat transfer to the outside air) is due to convection and radiation. Of these, the effect of convection is small. This is natural convection heat transfer with a small air movement (flow) because the refrigerator is used indoors and the back surface to which the heat sink is usually attached is used close to the wall. . Therefore, in the dissipation of heat from the heat sink, the contribution of heat transfer by radiation is large. Therefore, if the heat dissipation of the heat sink is excellent, the heat exchange efficiency of the entire refrigerator is improved and the power consumption is reduced. It also extends the life of parts and refrigerators.
一方、パソコン（特に、デスクトップ型パソコン）の場合、近年の著しい演算速度の上昇によってＣＰＵからの発熱量は大幅に増大しており、その熱の放散を向上させることが大きな課題となっている。通常、熱の放散のためにファンが用いられているが、回転数をあげて風量を増大させると騒音が大きくなるという問題がある。この場合も、パソコンの筐体からの放射による伝熱量を増すことができれば、ファンの回転数を増大させることなく、内部で発生した熱を速やかに外部に放散することができる。 On the other hand, in the case of a personal computer (especially a desktop personal computer), the amount of heat generated from the CPU is greatly increased due to a significant increase in computation speed in recent years, and it is a big issue to improve the heat dissipation. Usually, a fan is used to dissipate heat, but there is a problem that noise increases when the rotational speed is increased and the air volume is increased. Also in this case, if the amount of heat transfer by radiation from the housing of the personal computer can be increased, the heat generated inside can be quickly dissipated outside without increasing the rotational speed of the fan.
家電製品やパソコンを含む電気・電子製品の筐体や放熱板において要求される１５０℃程度以下での放熱性を向上させる技術として、下記特許文献１に、熱放射性に優れた表面処理材が開示されている。この表面処理材は基材の金属板の表面に１層以上の塗膜を備える塗装金属板であり、式(１)により算出される熱放射率αが６０％以上である。 As a technique for improving the heat dissipation at about 150 ° C. or less required for the casings and heat sinks of electric and electronic products including home appliances and personal computers, the following patent document 1 discloses a surface treatment material with excellent thermal radiation. Has been. This surface treatment material is a coated metal plate having one or more coating films on the surface of the metal plate of the base material, and the thermal emissivity α calculated by the equation (1) is 60% or more.
放熱板や電気・電子製品の筐体からの放射熱は波長８〜１０μｍにピークを有している。特許文献１に記載された表面処理材では、基材表面に形成された塗膜の最外層塗膜が、波長６μｍでの熱放射率が６０％以上の顔料と波長１２μｍでの熱放射率が６０％以上の顔料の両者を含有することにより、これらの顔料が熱放射特性を補完しあって、それぞれ単独で用いる場合に比べて高い熱放射性が得られる。例えば、波長６μｍで熱放射率が高いカーボンブラックと波長１２μｍで熱放射率が高いチタニアを、所定の量および／または質量比で外層塗膜に含有させると、内部で熱を生じる電気・電子製品の筐体や放熱板に好適であり、経済的にも有利であることがそこに記載されている。 Radiant heat from the heat sink and the housing of the electric / electronic product has a peak at a wavelength of 8 to 10 μm. In the surface treatment material described in Patent Document 1, the outermost layer coating film of the coating film formed on the substrate surface has a pigment having a thermal emissivity of 60% or more at a wavelength of 6 μm and a thermal emissivity at a wavelength of 12 μm. By containing both 60% or more of pigments, these pigments complement the heat radiation characteristics, and high heat radiation is obtained as compared with the case where each pigment is used alone. For example, electrical and electronic products that generate heat internally when carbon black with a high thermal emissivity at a wavelength of 6 μm and titania with a high thermal emissivity at a wavelength of 12 μm are contained in the outer layer coating film in a predetermined amount and / or mass ratio. It is described that it is suitable for a housing and a heatsink of the present invention and is economically advantageous.
下記特許文献２には、基材表面に外層塗膜と内層塗膜を備え、内層塗膜が上記(１)式により算出される熱放射率αが７０％以上の顔料を含有することにより内層塗膜の熱放射率αが７０％以上である表面処理材（好ましくは、金属板）が開示されている。 In the following Patent Document 2, an outer layer coating film and an inner layer coating film are provided on the surface of the base material, and the inner layer coating film contains a pigment having a thermal emissivity α calculated by the above formula (1) of 70% or more. A surface treatment material (preferably a metal plate) having a thermal emissivity α of the coating film of 70% or more is disclosed.
下記特許文献３には、着色可能な遠赤外線塗料組成物および遠赤外線ヒータが開示されている。この遠赤外線塗料組成物は、ケイ素アルコキシド、金属アルコキシド、それらの混合物、または部分縮合物等を含むビヒクル（展色剤）中に、遠赤外線放射顔料を所望により着色顔料および／または被覆層補強剤と一緒に含有する。遠赤外線放射顔料として、黒鉛、酸化物、ほう化物、炭化物、窒化物、フッ化物、ケイ素化合物、リン化合物、イオウ化合物または塩化物、並びにそれらの混合物および複合化合物が挙げられている。 Patent Document 3 listed below discloses a discolorable far-infrared paint composition and a far-infrared heater. This far-infrared coating composition comprises a far-infrared radiation pigment and, if desired, a coloring pigment and / or a coating layer reinforcing agent in a vehicle (color developing agent) containing silicon alkoxide, metal alkoxide, a mixture thereof, or a partial condensate. Contains together. Far-infrared emitting pigments include graphite, oxides, borides, carbides, nitrides, fluorides, silicon compounds, phosphorus compounds, sulfur compounds or chlorides, and mixtures and composite compounds thereof.
このように、電気・電子製品の筐体や放熱板の放熱性の改善は、従来は主として基材表面の塗膜（塗料）の熱放射率を高めることにより行われてきた。
一方で、プラズマテレビ、パソコンなどデジタルＩＣを使用したＩＴ家電やＯＡ機器など電子機器類が精密化し、一般に普及するに伴って、発振回路やスイッチング回路などの内部部品から発生する電磁波の漏洩による人体への影響が懸念されるようになってきた。特に欧米では、電子機器からの電磁波漏洩を一定以下に抑えることが求められている。また、外部から侵入する電磁波によって電子機器が誤動作を起こすことが知られており、誤動作およびそれによる事故を防止する観点から、電子機器内部への電磁波の侵入を抑制することが求められている。
Thus, the improvement of the heat dissipation of the casings and heat sinks of electrical / electronic products has been conventionally performed mainly by increasing the thermal emissivity of the coating film (paint) on the substrate surface.
On the other hand, as electronic devices such as plasma televisions and personal computers using digital ICs such as IT home appliances and OA equipment have become more precise and popularized, the human body due to leakage of electromagnetic waves generated from internal components such as oscillation circuits and switching circuits There is a growing concern about the impact on Particularly in Europe and the United States, it is required to suppress electromagnetic wave leakage from electronic devices to a certain level or less. In addition, it is known that an electronic device malfunctions due to electromagnetic waves entering from the outside. From the viewpoint of preventing malfunction and accidents caused by the malfunction, it is required to suppress the penetration of electromagnetic waves into the electronic device.
電磁波の漏洩あるいは侵入を抑制するため、電子機器および／またはその内部部品の筐体を金属製として電磁波をシールドすることが一般に知られている（以下、電子機器および／または内部部品の筐体を「電子機器筐体」と総称する）。そのためには、筐体が連続な導電体、典型的には金属であることが必要である。 In order to suppress leakage or intrusion of electromagnetic waves, it is generally known to shield the electromagnetic waves by using a metal casing for the electronic device and / or its internal components (hereinafter referred to as the electronic device and / or the internal component casing). Collectively referred to as “electronic device casing”). This requires that the housing be a continuous conductor, typically a metal.
しかし、実際の電子機器筐体は、金属板を成型加工して製造されることから、フランジなどの継目や接合部があるのが普通であり、その部分から電磁波の漏洩または侵入が生じやすい。そのため、このような継目にはガスケットとよばれる部材を用いて、電磁波シールド性が確保される。しかし、ガスケットの使用・不使用にかかわらず（好ましくはガスケットを使用しなくても）、このような接続部での導電性を向上させて電磁波シールド性を高めるために、金属板の表面の電気抵抗値（以下「表面抵抗値」と呼ぶ）を低くすることが必要である。 However, since an actual electronic device casing is manufactured by molding a metal plate, it usually has a joint such as a flange or a joint, and electromagnetic waves are likely to leak or enter from that portion. Therefore, an electromagnetic wave shielding property is ensured by using a member called a gasket for such a joint. However, regardless of the use or non-use of a gasket (preferably without using a gasket), in order to improve the conductivity at such a connection and enhance the electromagnetic wave shielding property, It is necessary to lower the resistance value (hereinafter referred to as “surface resistance value”).
ところが、熱放射率の高い顔料を多量に含有させた熱放射率の高い塗膜は、導電性が低いので、その塗膜が厚くなれば、金属板の表面の熱放射率は高まって熱吸収性は向上するが、表面の導電性は低下し、表面抵抗値が増大する。 However, a coating film with high thermal emissivity containing a large amount of a pigment with high thermal emissivity has low conductivity, so if the coating film becomes thicker, the thermal emissivity of the surface of the metal plate increases and heat absorption. However, the surface conductivity is lowered and the surface resistance value is increased.
このような熱放射率と導電性を両立する手法として、特許文献４には、基材を熱放射性の良好な合金化溶融亜鉛めっき鋼板とし、その片面には２層以上の塗膜を形成し、他方の面は熱放射率αが４０％以上である塗装鋼板が提案されている。基材の外面側のみを塗装して２層以上の塗膜を形成し、その最外層以外の１層以上の塗膜に少なくとも１種の放熱顔料を含有させる。一方、裏面側は、下地の化成処理として施された無機皮膜層または無機有機複合皮膜層のままとする。その皮膜層には所望により導電顔料や放熱顔料（例えば、カーボンブラックとチタニアの一方または両方）を含有させてもよく、放熱顔料を含有させると熱放射率はさらに高まる。これらの顔料は耐食性を劣化させるおそれがあるので、合計で皮膜層中の１０質量％以下にとどめるのが好ましく、より好ましくは５質量％以下である。
上記特許文献４に記載された塗装鋼板は、放熱性に優れ、耐食性と導電性も良好であって、放熱性と電磁波シールド性が求められる電子機器筐体に使用することができる。しかし、裏面側の熱放射率をさらに高めるために放熱顔料の添加量を増大させたり、放熱顔料と一緒に導電顔料を添加すると、耐食性が損なわれる。そのため、特許文献４では、放熱顔料と導電顔料の合計量が１０質量％以下、好ましくは５質量％以下とされている。 The coated steel sheet described in Patent Document 4 is excellent in heat dissipation, corrosion resistance and conductivity, and can be used in an electronic device casing that requires heat dissipation and electromagnetic wave shielding. However, if the amount of the heat-dissipating pigment is increased in order to further increase the heat emissivity on the back side, or if a conductive pigment is added together with the heat-dissipating pigment, the corrosion resistance is impaired. Therefore, in Patent Document 4, the total amount of the heat dissipating pigment and the conductive pigment is 10% by mass or less, preferably 5% by mass or less.
耐食性に関して、特許文献４の実施例において採用されている塩水噴霧試験７２時間での発錆面積率による評価では、要求が高度化している塗装鋼板の耐食性の評価には必ずしも十分ではないことを本発明者らは確認した。 Regarding the corrosion resistance, the evaluation based on the rusting area ratio in 72 hours of the salt spray test employed in the example of Patent Document 4 is not necessarily sufficient for evaluating the corrosion resistance of coated steel sheets, which are becoming increasingly demanding. The inventors confirmed.
本発明は、耐食性を保持したまま放熱性と導電性を改善でき、内部で熱を生じ、かつ電磁波シールドが必要な電気・電子製品の筐体や放熱板に好適な表面処理鋼板および塗装鋼板を提供することを課題とする。 The present invention provides a surface-treated steel sheet and a coated steel sheet that can improve heat dissipation and conductivity while maintaining corrosion resistance, generate heat inside, and are suitable for a casing or heat dissipation plate of an electric / electronic product that requires electromagnetic shielding. The issue is to provide.
本発明において、「熱放射率」、「熱放射性」とは、いずれも特に断らない限り、材料の表面（めっき面、化成処理皮膜面、または塗装面）の「熱放射率」、「熱放射性」をいう。また、めっき鋼板、表面処理鋼板、または塗装鋼板全体としての、あるいは塗装鋼板を筐体に組み立てたときの、高温側から低温側への放熱効果の程度を「放熱性」という。 In the present invention, “thermal emissivity” and “thermal emissivity” are “thermal emissivity” and “thermal emissivity” on the surface of the material (plated surface, chemical conversion coating surface, or painted surface) unless otherwise specified. ". In addition, the degree of the heat radiation effect from the high temperature side to the low temperature side when the plated steel plate, the surface-treated steel plate, the coated steel plate as a whole, or when the coated steel plate is assembled in a casing is referred to as “heat dissipation”.
本発明者らは、化成処理を多層化して、最下層以外の上層の化成処理層にカーボンブラックやチタニアなどの放熱顔料を添加することにより、耐食性を著しく損なうことなく、熱放射性と導電性を改善できることを見出した。 The present inventors have made the chemical conversion treatment multi-layered, and added a heat-dissipating pigment such as carbon black or titania to the chemical conversion treatment layer on the upper layer other than the lowermost layer, so that the heat radiation and conductivity can be improved without significantly deteriorating the corrosion resistance. I found that it can be improved.
本発明は、亜鉛系めっき鋼板からなる基材の少なくとも片面に２層の化成処理皮膜層を有し、この２層の化成処理皮膜層を有する基材の面が、該２層の化成処理皮膜層のみを有する時に７０％以上の熱放射率を示すことを特徴とする、表面処理鋼板である。 The present invention, on at least one surface of a substrate made of galvanized steel sheet has a chemical conversion coating layer of two layers, a surface of a substrate having a chemical conversion coating layer of the two layers, the chemical conversion coating of the two layers It is a surface-treated steel sheet characterized by exhibiting a thermal emissivity of 70% or more when having only a layer.
本発明の表面処理鋼板は、より具体的には、前記２層の化成処理皮膜層のうち、下層の化成処理皮膜層は顔料を含有しないか、その含有量が５質量％以下であり、上層の化成処理皮膜層が少なくともカーボンブラックを含む放熱顔料を１０〜２５質量％含有する。 Surface-treated steel sheet of the present invention, more specifically, of the chemical conversion coating layer of the two layers, the lower layer of chemical conversion coating layer or does not contain a pigment, and the content thereof is 5 mass% or less, the upper layer The chemical conversion treatment film layer contains 10 to 25% by mass of a heat dissipating pigment containing at least carbon black.
ここで、放熱顔料とは、波長６〜１２μｍにおける測定値から上記（１）式により算出される熱放射率αが７０％以上である顔料を意味する。
本発明の表面処理鋼板は好ましくは下記の通りである：
・前記２層の化成処理皮膜層の下層の化成処理皮膜層の付着量が１０ｍｇ／ｍ２以上、２００ｍｇ／ｍ２以下であり、上層の化成処理皮膜層の付着量は合計で１００ｍｇ／ｍ２以上、５００ｍｇ／ｍ２以下である；
・下層の化成処理皮膜層が上層の化成処理皮膜層より低温で焼付けられたものである；
前記２層の化成処理皮膜層が、いずれもＳｉ化合物と水系有機樹脂とを造膜成分とする皮膜である。
Here, the heat dissipating pigment means a pigment having a thermal emissivity α of 70% or more calculated from the measured value at a wavelength of 6 to 12 μm by the above formula (1).
The surface-treated steel sheet of the present invention is preferably as follows:
- the adhesion amount of the underlying chemical conversion coating layer of chemical conversion coating layer of the two layers 10 mg / m 2 or more, 200 mg / m 2 or less, the adhesion amount of the upper layer of chemical conversion coating layer total 100 mg / m 2 Above, 500 mg / m 2 or less;
The lower chemical conversion coating layer is baked at a lower temperature than the upper chemical conversion coating layer;
Each of the two chemical conversion treatment film layers is a film containing a Si compound and a water-based organic resin as film-forming components.
別の側面からは、本発明は上記表面処理鋼板の少なくとも片面に塗装が施されたものであることを特徴とする、塗装鋼板である。好ましい塗装鋼板は、亜鉛系めっき鋼板からなる基材の片面が前記２層の化成処理皮膜層を有する化成処理面であり、該基材の他方の面に塗装が施されている。 From another aspect, the present invention is a coated steel sheet, wherein at least one surface of the surface-treated steel sheet is coated. A preferable coated steel sheet is a chemical conversion treated surface in which one side of a base material made of a zinc-based plated steel sheet has the two chemical conversion coating layers, and the other side of the base material is coated.
本発明はさらに、上記塗装鋼板から製作された電気・電子製品用筐体および放熱板にも関する。好ましくは、これらの製品は、基材の片面が前記２層の化成処理皮膜層を有する化成処理面であり、他方の面に塗装が施されている塗装鋼板から、塗装が施された他方の面が外面を向くように製作される。 The present invention further relates to a housing for an electric / electronic product and a heat radiating plate manufactured from the coated steel plate. Preferably, in these products, one surface of the base material is a chemical conversion treatment surface having the two chemical conversion treatment coating layers, and the other surface coated with the other surface is coated with the other coated surface. It is manufactured so that the surface faces the outside.
本発明によれば、化成処理皮膜を多層化、好ましくは２層化することにより、耐食性を著しく損なわずに、化成処理皮膜層に多量の放熱顔料および場合により導電顔料を含有させることができる。その結果、化成処理皮膜だけで裏面側に必要な十分な放熱性および電磁波シールド性を付与することが可能となり、片面塗装の放熱性と電磁波シールド性に優れた塗装鋼板が実現可能となる。 According to the present invention, the chemical conversion coating is multilayered, preferably two layers, so that the chemical conversion coating layer can contain a large amount of heat-dissipating pigment and optionally a conductive pigment without significantly impairing the corrosion resistance. As a result, it is possible to provide sufficient heat dissipation and electromagnetic wave shielding necessary for the back side only with the chemical conversion treatment film, and a coated steel sheet having excellent heat dissipation and electromagnetic wave shielding properties for single-sided coating can be realized.
本発明の表面処理鋼板は、亜鉛系めっき鋼板を基材とし、その少なくとも片面に２層の化成処理皮膜層を有する。そして、この２層の化成処理皮膜層を有する基材の面が、該２層の化成処理皮膜層のみで７０％以上の熱放射率を示す。 The surface-treated steel sheet of the present invention uses a zinc-based plated steel sheet as a base material and has two chemical conversion coating layers on at least one surface thereof. Then, the surface of a substrate having a chemical conversion coating layer of the two layers, indicating the thermal emissivity of only 70% conversion coating layer of the two layers.
以下では、化成処理皮膜層が下層と上層の２層である本発明を説明する。 Hereinafter, the present invention will be described in which the chemical conversion treatment film layer has two layers of a lower layer and an upper layer .
基材の亜鉛系めっき鋼板とは、亜鉛めっき鋼板と亜鉛合金めっき鋼板とを包含する意味である。亜鉛合金めっきの例としては、これらに限られないが、亜鉛−鉄合金めっき、亜鉛−ニッケル合金めっき、亜鉛−アルミニウム合金めっきなどがある。亜鉛系めっき鋼板は電気めっき鋼板と溶融めっき鋼板のいずれであってもよい。本発明において基材として特に好ましい亜鉛系めっき鋼板は、熱放射性に優れている合金化溶融亜鉛めっき鋼板（ガルバニール鋼板、ＧＡと略記）である。しかし、電気亜鉛めっき鋼板（ＥＧと略記）、溶融亜鉛めっき鋼板（ＧＩと略記）を含む他の亜鉛系めっき鋼板も基材として使用可能である。 The galvanized steel sheet as a base material includes a galvanized steel sheet and a zinc alloy plated steel sheet. Examples of zinc alloy plating include, but are not limited to, zinc-iron alloy plating, zinc-nickel alloy plating, and zinc-aluminum alloy plating. The galvanized steel sheet may be either an electroplated steel sheet or a hot dip plated steel sheet. A particularly preferable zinc-based plated steel sheet as a base material in the present invention is an alloyed hot-dip galvanized steel sheet (galvanel steel sheet, abbreviated as GA) having excellent thermal radiation. However, other galvanized steel sheets including electrogalvanized steel sheets (abbreviated as EG) and hot dip galvanized steel sheets (abbreviated as GI) can also be used as the base material.
基材の亜鉛系めっき鋼板のめっき付着量（片面あたり）は特に制限されないが、耐食性確保に十分な量とする。一般に、電気めっき鋼板の場合は３〜５０ｇ／ｍ2、合金化溶融亜鉛めっき鋼板を含む溶融亜鉛めっき鋼板の場合は３０〜１００ｇ／ｍ2の付着量が好ましい。 The amount of coating (per side) of the galvanized steel sheet of the base material is not particularly limited, but is sufficient for ensuring corrosion resistance. In general, 3 to 50 g / m 2 in the case of electroplated steel sheet, the adhesion amount of 30 to 100 g / m 2 in the case of hot-dip galvanized steel sheet comprising a galvannealed steel sheet is preferable.
基材の亜鉛系めっき鋼板の片面又は両面に、本発明にしたがって２層の化成処理皮膜層を形成する。下層の化成処理皮膜層は、顔料を全く含有しないか、その含有量が５質量％以下であり、上層の化成処理皮膜層には、少なくともカーボンブラックを含む放熱顔料を１０〜２５質量％の量で含有させる。 According to the present invention, two chemical conversion coating layers are formed on one side or both sides of a galvanized steel sheet as a substrate. The lower chemical conversion coating layer contains no pigment or the content thereof is 5% by mass or less, and the upper chemical conversion coating layer contains 10 to 25% by mass of a heat dissipating pigment containing at least carbon black. To contain.
使用する放熱顔料は、波長６μｍでの熱放射率が７０％以上の顔料であるカーボンブラックを少なくとも含む。それに加えて、波長１２μｍでの熱放射率が７０％以上の顔料、例えば、チタニアを併用することが好ましい。こうすると、これらの顔料が熱放射特性を補完しあって、それぞれを単独で用いる場合に比べて高い熱放射性が得られる。このように２種以上の放熱顔料を使用する場合、放熱顔料の合計量に対するカーボンブラックの割合は５質量％以上とすることが好ましい。従って、上層の化成処理皮膜層は好ましくは少なくとも０.５質量％のカーボンブラックを含有する。 The heat-dissipating pigment used includes at least carbon black, which is a pigment having a thermal emissivity of 70% or more at a wavelength of 6 μm. In addition, it is preferable to use a pigment having a thermal emissivity of 70% or more at a wavelength of 12 μm, for example, titania. In this way, these pigments complement the heat radiation characteristics, and a high heat radiation property can be obtained as compared with the case where each pigment is used alone. Thus, when using 2 or more types of thermal radiation pigments, it is preferable that the ratio of carbon black with respect to the total amount of thermal pigments shall be 5 mass% or more. Accordingly, the upper chemical conversion coating layer preferably contains at least 0.5% by mass of carbon black.
使用可能な他の放熱顔料の例を挙げると、黒鉛、酸化物、ほう化物、炭化物、窒化物、フッ化物、ケイ素化合物、リン化合物、イオウ化合物または塩化物、並びにそれらの混合物および複合化合物が挙げられる。 Examples of other heat dissipation pigments that can be used include graphite, oxides, borides, carbides, nitrides, fluorides, silicon compounds, phosphorus compounds, sulfur compounds or chlorides, and mixtures and composite compounds thereof. It is done.
下層と上層の化成処理皮膜層に添加可能な放熱顔料以外の他の顔料としては、導電顔料、着色顔料、潤滑剤（ワックス等）、骨材（シリカ、樹脂ビーズ等）などがある。表面処理鋼板に電磁波シールド性を付与するため、化成処理皮膜層を低抵抗化したい場合には、導電顔料を少なくとも上層の化成処理皮膜層に添加してもよい。使用できる好ましい導電顔料としては、金属フィラーがある。ただし、本発明では、放熱顔料として使用するカーボンブラックが導電顔料としても機能しうる高い導電性を示すため、別に導電顔料を添加しなくても、化成処理皮膜層は十分な導電性を有する。放熱顔料以外の他の顔料を添加する場合、上層の化成処理皮膜層中の放熱顔料と合わせた顔料の合計量が５０質量％以下となるようにすることが好ましい。顔料の合計量がこれより多くなると耐食性が低下する。 Examples of pigments other than the heat dissipating pigment that can be added to the lower and upper chemical conversion coating layers include conductive pigments, colored pigments, lubricants (wax, etc.), aggregates (silica, resin beads, etc.), and the like. In order to impart electromagnetic shielding properties to the surface-treated steel sheet, when it is desired to reduce the resistance of the chemical conversion coating layer, a conductive pigment may be added to at least the upper chemical conversion coating layer. A preferable conductive pigment that can be used is a metal filler. However, in the present invention, since carbon black used as a heat-dissipating pigment exhibits high conductivity that can also function as a conductive pigment, the chemical conversion coating layer has sufficient conductivity even if a conductive pigment is not added separately. When adding a pigment other than the heat dissipating pigment, the total amount of the pigment combined with the heat dissipating pigment in the upper chemical conversion coating layer is preferably 50% by mass or less. When the total amount of the pigment is larger than this, the corrosion resistance is lowered.
下層の化成処理皮膜層が合計で５質量％以上の顔料を含有していると、表面処理鋼板の耐食性が低下する。一方、上層の化成処理皮膜層の放熱顔料の含有量が１０質量％未満では、表面処理鋼板の熱放射性が不十分となり、２５質量％を超えると、耐食性が著しく低下するとともに、塗料への分散性が困難となる。上層における放熱顔料の含有量は好ましくは１０〜２０質量％である。 When the lower chemical conversion coating layer contains 5% by mass or more of pigments in total, the corrosion resistance of the surface-treated steel sheet is lowered. On the other hand, if the content of the heat-dissipating pigment in the upper chemical conversion coating layer is less than 10% by mass, the thermal radiation of the surface-treated steel sheet is insufficient, and if it exceeds 25% by mass, the corrosion resistance is remarkably lowered and dispersed in the paint. It becomes difficult. The content of the heat dissipating pigment in the upper layer is preferably 10 to 20% by mass.
化成処理皮膜層は、基材鋼板に耐食性の化成処理皮膜を形成することができる任意の化成処理液から形成することができる。従って、化成処理皮膜層はクロメート処理液から形成されるクロメート皮膜であってもよい。しかし、周知のように、人体や環境に有害な６価クロムを含有するクロメート処理液はその使用が規制されているので、６価クロムを含有しない化成処理液や、さらには３価クロムも含めて、クロムを全く含有しないノンクロム化成処理液を用いて、上層と下層の化成処理皮膜層を形成することが好ましい。 A chemical conversion treatment film layer can be formed from the arbitrary chemical conversion treatment liquid which can form a corrosion-resistant chemical conversion treatment film in a base-material steel plate. Therefore, the chemical conversion treatment film layer may be a chromate film formed from a chromate treatment solution. However, as is well known, since the use of a chromate treatment liquid containing hexavalent chromium harmful to the human body and the environment is regulated, chemical conversion treatment liquid not containing hexavalent chromium and trivalent chromium are also included. Thus, it is preferable to form the upper and lower chemical conversion coating layers using a non-chromic chemical conversion treatment solution containing no chromium.
本発明において上層と下層の化成処理皮膜層を形成するのに特に好ましい化成処理液は、Ｓｉ化合物と水系樹脂とを造膜成分とする有機無機複合型の化成処理皮膜を形成することができる処理液である。 In the present invention, a particularly preferable chemical conversion treatment liquid for forming the upper and lower chemical conversion coating layers is a treatment capable of forming an organic-inorganic composite type chemical conversion coating using Si compounds and aqueous resins as film-forming components. It is a liquid.
無機系造膜成分であるＳｉ化合物としては、アルカリシリケート（例えば、Ｌｉシリケート）、シランカップリング剤［例えば、ビニルトリエトキシシラン、ビニルトリメトキシシラン、Ｎ−(２−アミノメチル)３−アミノプロピルメチルジメトキシシラン、Ｎ−(２−アミノメチル)３−アミノプロピルトリメトキシシラン、３−アミノプロピルトリメトキシシラン、３−グリシドキシプロピルトリメトキシシラン、３−グリシドキシプロピルメチルジメトキシシラン、２−(３,４−エポキシシクロヘキシル)エチルトリメトキシシラン、３−メタクリロキシプロピルトリメトキシシラン、３−メルカプトプロピルトリメトキシシラン］、テトラアルコキシシラン（アルキルシリケート）（例えば、テトラエトキシシラン、テトラメトキシシラン）、シリカ（例えば、液相シリカ、気相シリカ）などが挙げられる。シランカップリング剤やテトラアルコキシシランのような加水分解性Ｓｉ化合物は、その部分加水分解物の形態で使用することもできる。 Examples of the Si compound as an inorganic film-forming component include alkali silicate (for example, Li silicate), silane coupling agent [for example, vinyltriethoxysilane, vinyltrimethoxysilane, N- (2-aminomethyl) 3-aminopropyl. Methyldimethoxysilane, N- (2-aminomethyl) 3-aminopropyltrimethoxysilane, 3-aminopropyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, 3-glycidoxypropylmethyldimethoxysilane, 2- (3,4-epoxycyclohexyl) ethyltrimethoxysilane, 3-methacryloxypropyltrimethoxysilane, 3-mercaptopropyltrimethoxysilane], tetraalkoxysilane (alkyl silicate) (for example, tetraethoxysilane, tetramethoxysilane) ), Silica (for example, liquid phase silica, gas phase silica) and the like. Hydrolyzable Si compounds such as silane coupling agents and tetraalkoxysilanes can also be used in the form of partial hydrolysates.
有機造膜成分である水系有機樹脂は、水溶性樹脂とエマルジョン樹脂のいずれでもよい。例えば、水溶性フェノール樹脂、エマルジョン型のアクリル樹脂、ウレタン樹脂、ポリエステル樹脂、エポキシ樹脂などが使用できる。 The water-based organic resin that is an organic film-forming component may be either a water-soluble resin or an emulsion resin. For example, a water-soluble phenol resin, an emulsion type acrylic resin, a urethane resin, a polyester resin, an epoxy resin, or the like can be used.
Ｓｉ含有無機系造膜成分に、水系有機樹脂を併用して、化成処理皮膜を無機有機複合皮膜とすることで、皮膜の防錆機能を一層向上させることができる。ただし、水系有機樹脂を多めに配合すると、耐食性や指紋模様の残りにくさ（耐指紋性）は向上するが、導電性には好ましくないので、水系有機樹脂の配合比（固形分での量）は全皮膜量に対して５０質量％以下とするのが好ましい。 By using a water-based organic resin in combination with the Si-containing inorganic film-forming component and making the chemical conversion film a inorganic-organic composite film, the rust prevention function of the film can be further improved. However, adding a large amount of water-based organic resin improves corrosion resistance and the difficulty of remaining fingerprints (fingerprint resistance), but it is not preferable for conductivity, so the water-based organic resin compounding ratio (amount in solids) Is preferably 50% by mass or less based on the total coating amount.
化成処理皮膜層は、常法に従って、化成処理液の塗布と乾燥（通常は加熱による焼き付け）により形成される。
使用する化成処理液は、上記の有機および無機造膜成分に加えて、必要に応じて添加成分を含有する。すなわち、上層の化成処理皮膜層を形成するための化成処理液には、少なくともカーボンブラックを含有する放熱顔料を、処理液中の固形分に対して１０〜２５質量％となる量で添加し、さらに導電顔料その他の顔料を添加してもよい。下層の化成処理皮膜層を形成するための化成処理液にも、５質量％以下であれば、放熱顔料や導電顔料などを添加することができる。
The chemical conversion treatment film layer is formed by applying a chemical conversion treatment solution and drying (usually baking by heating) according to a conventional method.
The chemical conversion treatment liquid to be used contains an additive component as required in addition to the above organic and inorganic film-forming components. That is, to the chemical conversion treatment liquid for forming the upper chemical conversion treatment film layer, a heat dissipating pigment containing at least carbon black is added in an amount of 10 to 25% by mass with respect to the solid content in the treatment liquid, Further, a conductive pigment or other pigments may be added. If it is 5 mass% or less, a heat-radiation pigment, a conductive pigment, etc. can also be added to the chemical conversion liquid for forming a chemical conversion treatment film layer of a lower layer.
下層と上層の化成処理皮膜層は、放熱顔料の含有量が異なるが、その他の点では同組成の化成処理液から形成してもよく、あるいは顔料の添加量以外に、造膜成分の種類や含有量を互いに変化させた化成処理液から形成してもよい。いずれの化成処理液にも、上記以外の添加成分、例えば、Ｓｉ以外の無機造膜成分（例、Ｖ、Ｔｉ，Ｚｒ、Ｐの化合物）、加水分解触媒（酸）などを少量添加することができる。 The lower layer and the upper layer chemical conversion coating layer differ in the content of the heat-dissipating pigment, but otherwise may be formed from a chemical conversion treatment solution having the same composition, or in addition to the amount of pigment added, You may form from the chemical conversion liquid which changed content mutually. It is possible to add a small amount of an additive component other than the above, for example, an inorganic film-forming component other than Si (eg, a compound of V, Ti, Zr, P), a hydrolysis catalyst (acid), etc. to any chemical conversion treatment liquid. it can.
化成処理液の基材の亜鉛系めっき鋼板への塗布は、ロール塗布、浸漬、噴霧などの慣用手段で実施できる。下層形成用の化成処理液を塗布し、皮膜を焼き付けた後、上層形成用の化成処理液を塗布し、皮膜を焼き付けることが好ましい。下層の化成処理皮膜層の焼き付けは、焼き付けによる皮膜の硬化が不完全であっても、その後の上層皮膜の焼き付け時に完全に硬化する。従って、下層の化成処理皮膜層の焼き付けは、上層の化成処理皮膜層の焼き付けより低温で行なうことができ、その方が、上層の化成処理皮膜層の密着性が向上するので、かえって好ましい。密着性が向上する理由は下層の化成処理と上層の化成処理界面が上層化成処理焼き付け時に相互作用するためであると考えられる。また、化成処理皮膜にこのような密着性のよい界面が形成されることで、化成処理表面からの腐食因子の侵入を従来の一層の化成処理皮膜よりも抑制可能と考える。もちろん、エネルギーコストの面でも有利である。化成処理皮膜層の焼き付け温度は、下層が５０〜１２０℃、上層が６０〜２５０℃の範囲である。 Application | coating to the zinc-type plated steel plate of the base material of a chemical conversion liquid can be implemented by conventional means, such as roll application | coating, immersion, and spraying. It is preferable to apply the chemical conversion treatment liquid for forming the lower layer and bake the film, and then apply the chemical conversion liquid for formation of the upper layer to bake the film. In the baking of the lower chemical conversion coating layer, even when the coating is not completely cured by baking, it is completely cured when the upper layer coating is subsequently baked. Therefore, baking of the lower chemical conversion coating layer can be performed at a lower temperature than baking of the upper chemical conversion coating layer, which is more preferable because it improves the adhesion of the upper chemical conversion coating layer. The reason why the adhesion is improved is considered to be that the lower layer chemical conversion treatment and the upper chemical conversion treatment interface interact during baking of the upper chemical conversion treatment. Moreover, it is thought that the penetration | invasion of the corrosion factor from the chemical conversion treatment surface can be suppressed rather than the conventional one chemical conversion treatment film by forming such an interface with good adhesiveness in a chemical conversion treatment film. Of course, it is also advantageous in terms of energy cost. The baking temperature of the chemical conversion coating layer is in the range of 50 to 120 ° C. for the lower layer and 60 to 250 ° C. for the upper layer.
当業者には周知のように、使用した化成処理液が本質的に反応型のものである場合には、塗布後に通常は水洗を行ってから焼き付けをする。一方、化成処理液が塗布型である場合には、水洗せずに、焼き付けを行う。 As is well known to those skilled in the art, when the chemical conversion treatment solution used is essentially reactive, it is usually baked after being washed after application. On the other hand, when the chemical conversion treatment liquid is a coating type, baking is performed without washing.
下層の化成処理皮膜層の付着量は１０ｍｇ／ｍ2以上、２００ｍｇ／ｍ2以下であることが好ましく、より好ましくは３０ｍｇ／ｍ2以上、１５０ｍｇ／ｍ2以下である。下層の化成処理皮膜層の付着量が１０ｍｇ／ｍ2未満では、十分な耐食性が得られない。また、この付着量が２００ｍｇ／ｍ2を超えると、塗装性およびコストの観点から不利となる。 The adhesion amount of the lower chemical conversion coating layer is preferably 10 mg / m 2 or more and 200 mg / m 2 or less, more preferably 30 mg / m 2 or more and 150 mg / m 2 or less. If the adhesion amount of the lower chemical conversion coating layer is less than 10 mg / m 2 , sufficient corrosion resistance cannot be obtained. Moreover, when this adhesion amount exceeds 200 mg / m < 2 >, it will become disadvantageous from a viewpoint of paintability and cost.
一方、上層の化成処理皮膜層の付着量（３層以上の化成処理皮膜層の場合は、最下層以外の化成処理皮膜層の付着量の合計量）は１００ｍｇ／ｍ2以上、５００ｍｇ／ｍ2以下であることが好ましく、上限はさらに好ましくは３００ｍｇ／ｍ2である。上層の化成処理皮膜層の付着量が１００ｍｇ／ｍ2未満であると、顔料を加えても十分な熱放射性効果が得られない上、十分な耐食性も得られない。一方、この付着量が５００ｍｇ／ｍ2を超えると、導電性が低下し、コストの観点からも不利である。 On the other hand, the amount of adhesion of the upper chemical conversion coating layer (in the case of three or more chemical conversion coating layers, the total amount of chemical conversion coating layers other than the lowermost layer) is 100 mg / m 2 or more and 500 mg / m 2. The upper limit is preferably 300 mg / m 2 or more. When the adhesion amount of the upper chemical conversion coating layer is less than 100 mg / m 2 , a sufficient heat radiation effect cannot be obtained even when a pigment is added, and sufficient corrosion resistance cannot be obtained. On the other hand, when the adhesion amount exceeds 500 mg / m 2 , the conductivity is lowered, which is disadvantageous from the viewpoint of cost.
上述した上層と下層の２層の化成処理皮膜層は、基材の亜鉛系めっき鋼板の両面に形成してもよいが、片面に形成するだけで、本発明の目的を達成することができる。その場合、基材の反対側の面に塗装を施して、塗装鋼板とすることができる。この塗装鋼板は、塗装面を外面側に向け、２層の化成処理皮膜層を有する面は、無塗装のまま製品の内面（裏面）に向けられる。上記の２層の化成処理皮膜層は、耐食性に優れているので、無塗装でも基材の亜鉛系めっき鋼板を腐食から保護することができる。また、片面塗装とすることで、塗装鋼板の導電性が高まり、電磁波シールド機能を発揮できる。 The above-described two layers of the chemical conversion treatment film layer of the upper layer and the lower layer may be formed on both surfaces of the galvanized steel sheet of the base material, but the object of the present invention can be achieved only by forming it on one surface. In that case, it can coat on the surface on the opposite side of a base material, and can be set as a coated steel plate. In this coated steel sheet, the coated surface is directed to the outer surface side, and the surface having the two chemical conversion treatment film layers is directed to the inner surface (back surface) of the product without painting. Since the two chemical conversion coating layers are excellent in corrosion resistance, the zinc-based plated steel sheet as a base material can be protected from corrosion even without coating. Moreover, by setting it as single-sided coating, the electroconductivity of a coated steel plate increases and an electromagnetic wave shielding function can be exhibited.
基材の反対側の面は、塗装の前に、下地処理として化成処理が施されるのが普通である。この塗装下地の化成処理は、例えば、上述した下層の化成処理皮膜層の形成と同様の処理液から形成してもよい。その代わりに、あるいはそれに加えて、塗装下地として慣用の化成処理であるリン酸亜鉛処理を実施してもよい。 The opposite surface of the substrate is usually subjected to a chemical conversion treatment as a base treatment before coating. The chemical conversion treatment of the coating base may be formed from, for example, a treatment liquid similar to the formation of the lower chemical conversion treatment film layer described above. Instead, or in addition thereto, a zinc phosphate treatment, which is a conventional chemical conversion treatment, may be performed as a coating base.
塗装は鋼板の塗装に慣用されている各種の塗料を用い、常法に従って行なうことができる。ベース樹脂は、例えば、ポリエステル、ポリウレタン、エポキシ樹脂、アクリル樹脂および、これら樹脂の混合系などから選ぶことができる。 The coating can be performed according to a conventional method using various paints commonly used for coating steel sheets. The base resin can be selected from, for example, polyester, polyurethane, epoxy resin, acrylic resin, and a mixed system of these resins.
塗装は、下塗りと上塗りの２層の塗膜層を形成することにより行なうのが普通であるが、１層の塗膜層、あるいは３層以上の塗膜層とすることもできる。各塗膜層の膜厚は従来の塗装鋼板と同様でよい。 The coating is usually performed by forming two coating layers, an undercoat and an overcoat, but it can also be a single coating layer or three or more coating layers. The film thickness of each coating layer may be the same as that of a conventional coated steel sheet.
本発明の塗装鋼板は、上述した、片面が本発明に従って２層の化成処理皮膜層、反対側の面が塗装面であるものに限られない。例えば、基材の亜鉛系めっき鋼板の両面に、上述した２層の化成処理皮膜層を形成し、その両面又は片面に塗装を施してもよい。あるいは、基材の片面に上記２層の化成処理皮膜層を形成し、反対側の面は適宜の塗装下地処理を施した後、両面に塗装を施すこともできる。 The coated steel sheet of the present invention is not limited to the above-described one in which one surface is a two-layer chemical conversion coating layer according to the present invention and the opposite surface is a painted surface. For example, the two chemical conversion coating layers described above may be formed on both surfaces of a galvanized steel sheet as a base material, and coating may be performed on both surfaces or one surface thereof. Alternatively, the two chemical conversion coating layers may be formed on one side of the substrate, and the opposite side may be coated on both sides after appropriate coating ground treatment.
片面に上記の２層の化成処理皮膜層を形成し、反対側の面に塗装を施した本発明の塗装鋼板は、耐食性、放熱性、導電性の全ての面に優れているので、放熱性と電磁波シールド性が要求されるパソコンその他の電気・電子機器の筐体の製作に適している。また、冷蔵庫などの放熱板の製造にも使用できる。いずれの場合も、塗装面が外側になるように製品が製造される。 The coated steel sheet of the present invention in which the above-mentioned two chemical conversion coating layers are formed on one side and the opposite side is coated is excellent in all aspects of corrosion resistance, heat dissipation, and conductivity. It is suitable for the manufacture of housings for personal computers and other electrical and electronic equipment that require electromagnetic shielding properties. It can also be used to manufacture heat sinks such as refrigerators. In either case, the product is manufactured so that the painted surface is on the outside.
基材の亜鉛系めっき鋼板として、表１に示す合金化溶融亜鉛めっき鋼板（ＧＡ）、電気亜鉛めっき鋼板（ＥＧ）、溶融亜鉛めっき鋼板（ＧＩ）の３種類を使用した。鋼板はいずれも２５０×３００ｍｍのサイズであった。 Three types of galvanized steel sheets (GA), electrogalvanized steel sheets (EG), and hot dip galvanized steel sheets (GI) shown in Table 1 were used as the galvanized steel sheets for the substrate. All the steel plates were 250 × 300 mm in size.
各基材めっき鋼板の両面に、常法に従ってアルカリ脱脂及び水洗を行った後、表２からそれぞれ選んだ薬液（市販の化成処理液又はプライマー塗料に、場合により放熱顔料としてカーボンブラックを添加し、均一に分散させることにより調製、カーボンブラックの添加量は液中の全固形分に対する質量％）を、表３に記載の組み合わせの薬液および付着量（単位：ｍｇ／ｍ２）でバーコーターを用いて塗布し、各処理液の塗布後に水洗せずに焼き付けを行なって、下層と上層の化成処理皮膜層を形成した。 After performing alkaline degreasing and water washing on both surfaces of each substrate-plated steel sheet according to a conventional method, each of the chemicals selected from Table 2 (adding carbon black as a heat-dissipating pigment to a commercially available chemical conversion treatment solution or primer paint, prepared by uniformly dispersing, the addition amount of carbon black mass%) with respect to the total solid content in the liquid, the chemical liquid and the adhesion amount of a combination according to Table 3 (unit: a bar coater in m g / m 2) It applied and used, and it baked, without washing with water after application | coating of each process liquid, and formed the chemical conversion treatment film layer of the lower layer and the upper layer.
化成処理液はいずれもＳｉ含有化合物と水系有機樹脂を主な造膜成分とする有機無機複合処理型のものであった。なお、表２の薬液名のうち、ＥＣ２３３０は日本ペイント株式会社（Ｓｉ以外にＶ，Ｚｒ等を含有）、Ｅ３００ＳＷは日本パーカライジング株式会社（Ｓｉ以外にＰ，Ｔｉ等を含有）のそれぞれ製品である。 All of the chemical conversion treatment liquids were of an organic-inorganic composite treatment type using Si-containing compounds and aqueous organic resins as main film-forming components. Of the chemical names in Table 2, EC2330 is a product of Nippon Paint Co., Ltd. (containing V, Zr, etc. in addition to Si), and E300SW is a product of Nihon Parkerizing Co., Ltd. (containing P, Ti, etc. in addition to Si). .
焼き付け温度は、下層の皮膜層は８０℃、上層の皮膜層は２２０℃であった。加熱時間は下層が７.５秒間、上層が４５秒間であった。一部の例では下層の形成を省略して、皮膜層を１層とした。こうして、基材の両面に同じ皮膜構成の化成処理皮膜層を形成した表面処理鋼板を得た。 The baking temperature was 80 ° C. for the lower coating layer and 220 ° C. for the upper coating layer. The heating time was 7.5 seconds for the lower layer and 45 seconds for the upper layer. In some examples, the formation of the lower layer was omitted, and the coating layer was one layer. Thus, a surface-treated steel sheet in which the chemical conversion treatment film layer having the same film configuration was formed on both surfaces of the base material was obtained.
各表面処理鋼板について、下記の要領で耐食性、熱放射率および導電性を調査した。それらの結果も表３に一緒に示す。
(１)耐食性試験
塗装鋼板の各サンプルから７０ｍｍ×１５０ｍｍのサイズの試験片をシャーリングにより切り出し、切断端面にシールをした後、ＪＩＳに指定された条件で１２０時間の塩水噴霧試験に供した。その後、シールをした端面部分を除く平面部分の腐食状況（錆の種類、腐食面積）を測定した。評価基準は下記の通りであり、○を合格とする：
○：腐食面積率２０％未満、
△：腐食面積率２０％以上、５０％未満
×：腐食面積率５０％以上。
Each surface-treated steel sheet was examined for corrosion resistance, thermal emissivity, and conductivity in the following manner. The results are also shown in Table 3.
(1) Corrosion resistance test A test piece having a size of 70 mm x 150 mm was cut out from each sample of the coated steel sheet by shearing, and the cut end face was sealed, and then subjected to a salt spray test for 120 hours under the conditions specified by JIS. Thereafter, the corrosion state (rust type, corrosion area) of the flat portion excluding the sealed end face portion was measured. The evaluation criteria are as follows, and ○ is acceptable:
○: Corrosion area ratio less than 20%,
Δ: Corrosion area ratio 20% or more, less than 50% ×: Corrosion area ratio 50% or more.
（２）熱放射率測定
BIORAD社製の赤外吸収スペクトル測定装置を使用して、２.５μｍから２５μｍの波長領域の分光反射スペクトル（Ｒ（λ））を測定した。測定された分光反射スペクトル（Ｒ(λ)）を前記の（１）式に代入し、積分の下限を２.５として、熱放射率を求めた。評価基準は下記の通りであり、○、◎を合格とする。
(2) Thermal emissivity measurement
The spectral reflection spectrum (R (λ)) in the wavelength region of 2.5 μm to 25 μm was measured using an infrared absorption spectrum measuring device manufactured by BIORAD. The measured spectral reflectance spectrum (R (λ)) was substituted into the above equation (1), and the thermal emissivity was determined by setting the lower limit of integration to 2.5. The evaluation criteria are as follows, and ○ and ◎ are acceptable.
◎：熱放射率８０％以上、
○：熱放射率７０％以上、８０％未満、
△：熱放射率３０％以上、７０％未満、
×：熱放射率３０％未満。
A: Thermal emissivity of 80% or more,
○: Thermal emissivity 70% or more, less than 80%,
Δ: Thermal emissivity 30% or more, less than 70%,
X: Thermal emissivity is less than 30%.
(３)表面抵抗値の測定
図１に示す装置を用いて表面抵抗値を測定した。金属メッシュを絶縁材に巻きつけたガスケット１３（フォーム化成製ＥＧＵ−０５０５）を介して、その上下にサンプル１４Ａ、１４Ｂ（それぞれ１００ｍｍ角）をガスケット１３、１３に対して処理面が接触するように設置した。外部からの荷重はかけなかった。各サンプル１４Ａ、１４Ｂの端面にリード線１１をハンダ着け１５により接続して、１００ｍＡの電流を通電した時の電圧を測定して、表面抵抗値を算出した。評価基準は下記の通りであり、○を合格とする。
(3) Measurement of surface resistance value The surface resistance value was measured using the apparatus shown in FIG.
○：表面抵抗値５Ω未満、
△：表面抵抗値５Ω以上、１０Ω未満、
×：表面抵抗値１０Ω以上。
○: Surface resistance value of less than 5Ω
Δ: Surface resistance value of 5Ω or more and less than 10Ω,
×: Surface resistance value of 10Ω or more.
表３、４からわかるように、放熱顔料を含有しない下層と、適量の放熱顔料を含有する上層の２層の有機無機複合型の化成処理皮膜層を有する実施例の表面処理鋼板は、耐食性が良好であり、熱放射率と導電性の結果も良好であった。すなわち、上層の化成処理皮膜層に放熱顔料を従来より多量に含有させることにより、耐食性を損なわずに、放熱性と導電性を改善することができた。 As can be seen from Tables 3 and 4, the surface-treated steel sheet of the example having the organic-inorganic composite type chemical conversion coating layer of the lower layer not containing the heat-dissipating pigment and the upper layer containing the appropriate amount of the heat-dissipating pigment has corrosion resistance. It was good and the results of thermal emissivity and conductivity were also good. That is, heat dissipation and conductivity could be improved without impairing the corrosion resistance by incorporating a larger amount of the heat-dissipating pigment in the upper chemical conversion coating layer than before.
これに対し、下層の化成処理皮膜層を省略して、放熱顔料を含有する化成処理皮膜層のみを形成したＮｏ.２０〜２８の表面処理鋼板では、付着量に関係なく、耐食性が低くなった。また、下層の化成処理皮膜層に比較的多量の放熱顔料を含有させ、上層の化成処理皮膜層は放熱顔料を含有しなかったＮｏ.２９〜３４の表面処理鋼板では、耐食性がさらに悪化した。 On the other hand, in the surface-treated steel sheets No. 20 to 28 in which the lower chemical conversion coating layer was omitted and only the chemical conversion coating layer containing the heat-dissipating pigment was formed, the corrosion resistance was low regardless of the amount of adhesion. . Further, in the surface-treated steel sheets of Nos. 29 to 34 in which a relatively large amount of the heat-dissipation pigment was contained in the lower chemical conversion treatment film layer and the upper chemical conversion treatment film layer did not contain the heat dissipation pigment, the corrosion resistance was further deteriorated.
Ｎｏ.３５〜４０は上層の化成処理皮膜層が放熱顔料を含有せず、下層をいろいろ変化させた例であるが、少なくとも一つの特性が低下した。上層の化成処理皮膜層を樹脂皮膜層に変更したＮｏ.４１〜４８では、導電性が著しく悪く、他の特性も場合により低下した。 Nos. 35 to 40 are examples in which the upper chemical conversion film layer did not contain a heat-dissipating pigment and the lower layer was variously changed, but at least one characteristic was deteriorated. In No. 41-48 which changed the chemical conversion treatment film layer of the upper layer into the resin film layer, the conductivity was remarkably bad, and other characteristics were also lowered in some cases.
別の観点から見ると、化成処理層を１層のみ（例えばＮｏ.２６）とするよりも、２層（例えばＮｏ.１０）にする方が、同等の耐食性を確保するのに総付着量を少なくできることがわかる。つまり、化成処理が１層のみであるＮｏ.２６では、その付着量が６００ｍｇ／ｍ２と多いにもかかわらず、耐食性の評価が△である。これに対し、それよりも総付着量が少ないＮｏ.１０の本発明の実施例（下層の付着量が７５ｍｇ／ｍ２、上層の付着量が３００ｍｇ／ｍ２で合計３７５ｍｇ／ｍ２）では、より薄膜であるにもかかわらず耐食性の評価が○である。これは、化成処理層を２層にすることで下層の化成処理層と上層の化成処理層の間に界面が形成され、それによって化成処理表面からの腐食因子の侵入を従来の１層の化成処理皮膜よりも抑制できるためと考えられる。 From another point of view, the amount of total adhesion is less when the chemical conversion treatment layer is two layers (for example, No. 10) than the one layer (for example, No. 26) in order to ensure the equivalent corrosion resistance. You can see that it can be reduced. That is, in No. 26 in which the chemical conversion treatment is only one layer, the corrosion resistance evaluation is Δ even though the adhesion amount is as large as 600 mg / m 2 . On the other hand, in the example of the present invention of No. 10 having a smaller total adhesion amount than that (the lower layer adhesion amount is 75 mg / m 2 and the upper layer adhesion amount is 300 mg / m 2 , the total is 375 mg / m 2 ), Despite being a thinner film, the evaluation of corrosion resistance is ○. This is because by forming the chemical conversion treatment layer into two layers, an interface is formed between the lower chemical conversion treatment layer and the upper chemical conversion treatment layer, thereby preventing the invasion of the corrosion factor from the chemical conversion treatment surface. It is thought that it can suppress rather than a processing film.
基材の亜鉛系めっき鋼板として、表５に示す合金化溶融亜鉛めっき鋼板（ＧＡ）１種類を使用した。鋼板はいずれも２５０×３００ｍｍのサイズであった。
ＧＡ基材めっき鋼板の両面に、常法に従ってアルカリ脱脂及び水洗を行った後、表６からそれぞれ選んだ薬液（市販の同じ化成処理液に、場合により放熱顔料としてカーボンブラックおよび／またはチタニアを添加し、均一に分散させることにより調製、カーボンブラックとチタニアの添加量は液中の全固形分に対する質量％）を、表７に記載の組み合わせの薬液および付着量（単位：ｍｇ／ｍ２）でバーコーターを用いて塗布し、各処理液の塗布後に水洗せずに焼き付けを行なって、下層と上層の化成処理皮膜層を形成した。化成処理液はいずれもＳｉ含有化合物と水系有機樹脂を造膜成分とする有機無機複合処理型のものであった。
One type of galvannealed steel sheet (GA) shown in Table 5 was used as the galvanized steel sheet for the substrate. All the steel plates were 250 × 300 mm in size.
After performing alkali degreasing and water washing on both sides of the GA base plate steel plate according to a conventional method, each chemical solution selected from Table 6 (additionally carbon black and / or titania as a heat dissipation pigment to the same chemical conversion treatment solution on the market) and, prepared by uniformly dispersing, the addition of carbon black and titania mass%) with respect to the total solid content in the liquid, the chemical liquid and the adhesion amount of a combination according to Table 7 (unit: m g / m 2) Then, after applying each treatment solution, baking was performed without washing with water to form a lower and upper chemical conversion coating layer. All of the chemical conversion treatment liquids were of an organic / inorganic composite treatment type using a Si-containing compound and a water-based organic resin as film-forming components.
焼き付け温度は、下層の皮膜層は８０℃、上層の皮膜層は２２０℃であった。加熱時間は下層が７.５秒間、上層が４５秒間であった。こうして、基材の両面に同じ皮膜構成の化成処理皮膜層を形成した表面処理鋼板を得た。 The baking temperature was 80 ° C. for the lower coating layer and 220 ° C. for the upper coating layer. The heating time was 7.5 seconds for the lower layer and 45 seconds for the upper layer. Thus, a surface-treated steel sheet in which the chemical conversion treatment film layer having the same film configuration was formed on both surfaces of the base material was obtained.
各表面処理鋼板について、実施例１に記載したのと同じ要領および評価基準で耐食性、熱放射率および導電性を調査した。それらの結果も表７に一緒に示す。 Each surface-treated steel sheet was examined for corrosion resistance, thermal emissivity, and conductivity in the same manner and evaluation criteria as described in Example 1. The results are also shown in Table 7.
本実施例では、上層と下層の化成処理皮膜は、放熱顔料の種類と添加量が異なることを除けば同じものであった。表７からわかるように、本発明に従って放熱顔料を含有しない下層と、適量の放熱顔料を含有する上層の２層の有機無機複合型の化成処理皮膜層を有する実施例の表面処理鋼板は、耐食性が良好であり、熱放射率と導電性の結果も良好であった。これに対し、下層にも放熱顔料を５質量％より多量に含有させた比較例の表面処理鋼板では、上層の放熱顔料の含有量に関係なく、耐食性が低くなった。 In the present Example, the chemical conversion treatment film of the upper layer and the lower layer was the same except that the kind and the addition amount of the heat dissipating pigment were different. As can be seen from Table 7, according to the present invention, the surface-treated steel sheet of the example having two layers of the organic-inorganic composite-type chemical conversion coating layer including the lower layer not containing the heat-dissipating pigment and the upper layer containing the appropriate amount of the heat-dissipating pigment is corrosion resistant. And the results of thermal emissivity and conductivity were also good. On the other hand, in the surface-treated steel sheet of the comparative example in which the lower layer contains the heat-dissipating pigment in an amount of more than 5% by mass, the corrosion resistance was low regardless of the content of the upper-layer heat-dissipating pigment.
Claims (10)
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008069774A JP5061978B2 (en) | 2008-03-18 | 2008-03-18 | Surface-treated steel sheets and coated steel plates with excellent corrosion resistance, heat radiation, and conductivity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2008069774A JP5061978B2 (en) | 2008-03-18 | 2008-03-18 | Surface-treated steel sheets and coated steel plates with excellent corrosion resistance, heat radiation, and conductivity |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JP2009220511A JP2009220511A (en) | 2009-10-01 |
| JP5061978B2 true JP5061978B2 (en) | 2012-10-31 |
Family
ID=41237816
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2008069774A Active JP5061978B2 (en) | 2008-03-18 | 2008-03-18 | Surface-treated steel sheets and coated steel plates with excellent corrosion resistance, heat radiation, and conductivity |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP5061978B2 (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2012054001A (en) * | 2010-08-31 | 2012-03-15 | Nitto Denko Corp | Heat dissipation housing, lithium battery pack using the same, and semiconductive tape for heat dissipation |
| JP2013072560A (en) * | 2011-09-26 | 2013-04-22 | Daikin Industries Ltd | Outer wall panel of air conditioning outdoor unit |
| RU2663655C1 (en) | 2015-03-31 | 2018-08-08 | Ниссин Стил Ко., Лтд. | Heat-absorbing and heat-radiating steel sheet and heat-absorbing and heat-radiating element |
| WO2016208621A1 (en) * | 2015-06-25 | 2016-12-29 | 新日鐵住金株式会社 | Coated steel plate |
| CN117222774A (en) * | 2021-04-08 | 2023-12-12 | 日本制铁株式会社 | Steel plates and hot stamping components for hot stamping |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP4078044B2 (en) * | 2001-06-26 | 2008-04-23 | 日本パーカライジング株式会社 | Metal surface treatment agent, surface treatment method of metal material, and surface treatment metal material |
| WO2003087432A1 (en) * | 2002-04-12 | 2003-10-23 | Nippon Steel Corporation | Cover for exothermic article excellent in heat absorbing property and surface treated metal sheet therefor, and applications thereof |
| JP4736314B2 (en) * | 2003-01-23 | 2011-07-27 | 住友金属工業株式会社 | Heat-dissipating surface-treated metal plate and housing for electronic equipment |
| WO2005105432A1 (en) * | 2004-04-28 | 2005-11-10 | Sumitomo Metal Industries, Ltd. | Coated steel sheet with excellent heat dissipation |
| JP4442437B2 (en) * | 2005-01-20 | 2010-03-31 | 住友金属工業株式会社 | Painted steel plate with excellent weather resistance and corrosion resistance |
| JP2006291279A (en) * | 2005-04-11 | 2006-10-26 | Toyo Kohan Co Ltd | Electrically conductive black plated steel sheet |
| JP2006291280A (en) * | 2005-04-11 | 2006-10-26 | Toyo Kohan Co Ltd | Heat radiating black steel sheet |
| JP5055822B2 (en) * | 2006-04-27 | 2012-10-24 | 住友金属工業株式会社 | Painted steel sheet with excellent coating adhesion |
-
2008
- 2008-03-18 JP JP2008069774A patent/JP5061978B2/en active Active
Also Published As
| Publication number | Publication date |
|---|---|
| JP2009220511A (en) | 2009-10-01 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US9051654B2 (en) | Galvanized steel sheet | |
| US7279218B2 (en) | Coated body having excellent thermal radiation property used for members of electronic device | |
| JP4765936B2 (en) | Painted steel plate with excellent heat dissipation | |
| JP5061978B2 (en) | Surface-treated steel sheets and coated steel plates with excellent corrosion resistance, heat radiation, and conductivity | |
| JP3563731B2 (en) | Painted body for electronic equipment with excellent heat dissipation and conductivity | |
| KR20060106666A (en) | Painted metal material with excellent heat dissipation | |
| JP5201228B2 (en) | Heat-dissipating surface-treated metal plate and housing for electronic equipment | |
| JP4188857B2 (en) | Coated body for electronic device members with excellent heat dissipation and electronic device parts | |
| JP4736314B2 (en) | Heat-dissipating surface-treated metal plate and housing for electronic equipment | |
| TWI249580B (en) | Resin coated metal sheet | |
| JP4369761B2 (en) | Heating element cover excellent in heat absorption, surface-treated metal plate therefor, and applications thereof | |
| KR100563919B1 (en) | High thermal emissive coated bodies for electronic equipment parts | |
| JP4202974B2 (en) | Resin-coated metal sheet for electronic equipment members with excellent electromagnetic wave absorption and workability | |
| JP3796257B2 (en) | Coated body for electronic device members having excellent heat dissipation and self-cooling properties, and electronic device parts | |
| JP4194041B2 (en) | Resin-coated metal plate and electronic device parts with excellent scratch resistance and fingerprint resistance | |
| JP5459574B2 (en) | Chromate-free surface-treated metal material with excellent fingerprint resistance and electromagnetic shielding properties | |
| JP3796249B2 (en) | Coated body for electronic equipment members having excellent heat dissipation, self-cooling and electrical conductivity, and electronic equipment parts | |
| JP3796232B2 (en) | Painted body for electronic equipment with excellent heat dissipation | |
| JP2010007099A (en) | Chromate-free surface treated metal plate | |
| JP5789242B2 (en) | Coated metal sheet | |
| JP2004074145A5 (en) | ||
| JP2004134722A (en) | Cabinet for electric/electronic apparatus with high cooling power | |
| JP2004224017A (en) | Painted steel sheet with high cooling power | |
| JP2006095709A (en) | Coated steel panel excellent in conductivity/heat absorbing and releasing properties | |
| TH116046A (en) | The coated body with excellent heat radiation properties is applied to the parts. Assembly of electronic equipment |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A621 | Written request for application examination |
Free format text: JAPANESE INTERMEDIATE CODE: A621 Effective date: 20100326 |
|
| A977 | Report on retrieval |
Free format text: JAPANESE INTERMEDIATE CODE: A971007 Effective date: 20110722 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20110802 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20110929 |
|
| A131 | Notification of reasons for refusal |
Free format text: JAPANESE INTERMEDIATE CODE: A131 Effective date: 20120529 |
|
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A523 Effective date: 20120620 |
|
| TRDD | Decision of grant or rejection written | ||
| A521 | Written amendment |
Free format text: JAPANESE INTERMEDIATE CODE: A821 Effective date: 20120620 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 Effective date: 20120710 |
|
| A01 | Written decision to grant a patent or to grant a registration (utility model) |
Free format text: JAPANESE INTERMEDIATE CODE: A01 |
|
| A61 | First payment of annual fees (during grant procedure) |
Free format text: JAPANESE INTERMEDIATE CODE: A61 Effective date: 20120723 |
|
| R150 | Certificate of patent or registration of utility model |
Ref document number: 5061978 Country of ref document: JP Free format text: JAPANESE INTERMEDIATE CODE: R150 Free format text: JAPANESE INTERMEDIATE CODE: R150 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20150817 Year of fee payment: 3 |
|
| S111 | Request for change of ownership or part of ownership |
Free format text: JAPANESE INTERMEDIATE CODE: R313111 |
|
| FPAY | Renewal fee payment (event date is renewal date of database) |
Free format text: PAYMENT UNTIL: 20150817 Year of fee payment: 3 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |
|
| S533 | Written request for registration of change of name |
Free format text: JAPANESE INTERMEDIATE CODE: R313533 |
|
| R350 | Written notification of registration of transfer |
Free format text: JAPANESE INTERMEDIATE CODE: R350 |