JP4369761B2 - Heating element cover excellent in heat absorption, surface-treated metal plate therefor, and applications thereof - Google Patents

Description

【０１１０】
【表２】

【０１１１】
【表３】

【０１１２】
【表４】

【０１１３】
【表５】

【０１１４】
表１〜４中、（＊１）〜（＊１９）の注については、以下のとおりである。
（＊１）：塗料中の樹脂固形分１００質量部に対する添加顔料の質量部
（＊２）：東海カーボン社製「トーカブラック＃７３５０Ｆ」を使用（２８ｎｍ／微粒子カーボン）
（＊３）：共同組合ラテスト製「備長炭パウダー」を使用（最大粒径：５μｍ／大粒径カーボンＡ）
（＊４）：試薬の黒鉛末を更に粉砕し、ふるい分け分級機にて平均粒径１０μｍとしたものを使用
（＊５）東海カーボン社製「トーカブラック＃５５００Ｆ」を使用（粒径：２５ｎｍ）
（＊６）：市販のフレーク状金属Ｎｉと鎖状金属Ｎｉを入手し、質量比でフレークＮｉ／鎖状Ｎｉ＝６となるように混合したものを使用（平均粒径：５μｍ）
（＊７）：市販のフレーク状金属Ｎｉと鎖状金属Ｎｉを入手し、質量比でフレークＮｉ／鎖状Ｎｉ＝１となるように混合したものを使用（平均粒径：５μｍ）
（＊８）：市販のフレーク状金属Ｎｉと鎖状金属Ｎｉを入手し、質量比でフレークＮｉ／鎖状Ｎｉ＝０．１となるように混合したものを使用（平均粒径：５μｍ）
（＊９）：東洋アルミ社製「アルミニウム粉０２−０００５」を使用（平均粒径：１０μｍ）
（＊１０）：市販のステンレス粉を使用（平均粒径：２０μｍ）
（＊１１）：ＪＩＳ−Ｇ２３０２記載のフェロシリコン２号を粉砕機にて粉砕し、ふるい分け分級機にて平均粒径１０μｍとしたものを使用
（＊１２）：市販のフレーク状金属Ｎｉと鎖状金属Ｎｉを入手し、質量比でフレークＮｉ／鎖状Ｎｉ＝０．０５となるように混合したものを使用（平均粒径：５μｍ）
（＊１３）：市販のフレーク状金属Ｎｉと鎖状金属Ｎｉを入手し、質量比でフレークＮｉ／鎖状Ｎｉ＝７となるように混合したものを使用（平均粒径：５μｍ）
（＊１４）：日本アエロジル社製「ＡＥＲＯＳＩＬ３００」を使用（１２ｎｍ）
（＊１５）：Ｇｒａｃｅ社製「シールデクスＣ３０３」を使用（３μｍ）
（＊１６）：テイカ社製「Ｋ−ＷＨＩＴＥ Ｋ−１０５」を使用（平均粒径：２．３μｍ）
（＊１７）：日産化学社製「スノーテックスＮ」を使用（本防錆顔料は水分散タイプのため、表中に記載した添加量は固形分の量を示す、粒径：１０〜２０ｎｍ）
（＊１８）：大日精化学工業社製「ＡＦブラックＵ１４」を使用（本防錆顔料は樹脂混合の水分散タイプのため、表中に記載した添加量はカーボンブラックのみの量を示す、粒径：１０〜５０ｎｍ）
（＊１９）：石原産業社製酸化チタン「タイペークＣＲ９５」を使用
（＊２０）：試薬の黒鉛末を更に粉砕し、ふるい分け分級機にて平均粒径４０μｍとしたものを使用（大粒径カーボンＢ）
（＊２１）：試薬の黒鉛末を更に粉砕し、ふるい分け分級機にて平均粒径６０μｍとしたものを使用（大粒径カーボンＣ）
【０１１５】
なお、表１〜４中のバインダーはいずれも常乾溶剤系である。
以下、実施例の詳細について詳細を説明する。
【０１１６】
（実施例Ｉ）
以下、実験に用いた熱吸収性表面塗装板の作成方法について詳細を説明する。
付着量が片面当たり２０ｇ／ｍ² で両面がめっきされた厚み０．６ｍｍの電気亜鉛めっき鋼板を、市販のアルカリ脱脂剤である日本パーカライジング社製の「ＦＣ−３６４Ｓ」を２０質量％濃度に希釈した６０℃温度の水溶液中に１０秒間浸漬することで脱脂し、水洗後、乾燥した。
【０１１７】
次いで、脱脂した電気亜鉛めっき鋼板上にロールコーターにて前処理液を塗布し、到達板温が６０℃となるような条件で熱風乾燥させた。
【０１１８】
本実験では、前処理に市販のクロメート処理である日本パーカライジング社製の「ＺＭ１３００ＡＮ」（以下クロメート処理）と、市販のノンクロメート前処理である日本パーカライジング社製の「ＣＴ−Ｅ３００」（以下ノンクロメート処理）を使用した。
【０１１９】
クロメート処理の付着量は、Ｃｒ付着量で５０ｍｇ／ｍ²、ノンクロメート処理の付着量は、全皮膜量として２００ｍｇ／ｍ²とした。
【０１２０】
更に、前処理を施した電気亜鉛めっき鋼板の上に、表１に記載する熱吸収性皮膜塗料をロールコーターにて塗装し、熱風を併用した誘導加熱炉にて乾燥硬化させた。乾燥硬化条件は、到達板温（ＰＭＴ）で２３０℃とした。前処理及び熱吸収性皮膜塗料は必要に応じて片面もしくは両面に塗装することで試験片を得た。
【０１２１】
作成した表面塗装板の詳細を表５〜８に記載する。なお、表５〜７中に記載の表面塗装板は、いずれも、同じ種類の熱吸収性皮膜層を両面に同じ条件で被覆したものであり、表８中記載の表面塗装板は、いずれも、片面のみに熱吸収性皮膜層を被覆し、他の面は被覆していないものである。
【０１２２】
【表６】

【０１２３】
【表７】

【０１２４】
【表８】

【０１２５】
【表９】

【０１２６】
以下、作成した表面塗装板の評価試験について詳細を説明する。
【０１２７】
１）表面塗装板の放射率測定
日本分光社製のフーリエ変換赤外分光光度計「ＶＡＬＯＲ−III 」を用いて、表面塗装板の板温度を８０℃にしたときの波数６００〜３０００ｃｍ^-1の領域における赤外発光スペクトルを測定し、これを標準黒体の発光スペクトルと比較することで、表面塗装板の全放射率を測定した。なお、標準黒体は鉄板にタコスジャパン社販売（オキツモ社製造）の「ＴＨＩ−１Ｂ黒体スプレー」を３０±２μmの膜厚でスプレー塗装したものを用いた。
【０１２８】
２）表面塗装板の熱吸収性測定試験
図２に示す測定箱を作成して試験を行った。測定箱４は上面が開放されており、この開放された面を、作成した表面塗装板５で覆い、この状態で、熱源６の温度が１００℃となるように、温度コントローラー７にて熱源の温度を制御して、測定箱４内に設置した熱電対８の温度Ａと表面塗装板外面に貼り付けた熱電対９の温度Ｂを、それぞれ、デジタル温度計１０で測定した。
【０１２９】
更に、評価する表面塗装板と同じ板厚の未処理の電気亜鉛めっき鋼板についても、同様の測定を行い、作成した表面塗装板と未処理の電気亜鉛めっき鋼板との測定値を比較して、以下の基準で評価した。
【０１３０】
温度Ａの評価基準は以下のとおりである。
［｛（電気亜鉛めっき鋼板の測定値）−（評価する表面塗装板での測定値）｝≧４℃］のとき：○
［４℃＞｛（電気亜鉛めっき鋼板の測定値）−（評価する表面塗装板での測定値）｝≧２℃］のとき：△
［２℃＞｛（電気亜鉛めっき鋼板の測定値）−（評価する表面塗装板での測定値）｝］のとき：×
また、温度Ｂの評価基準は以下のとおりである。
［２０℃≧｛（評価する表面塗装板での測定値）−（電気亜鉛めっき鋼板の測定値）｝］のとき：○
［３０℃≧｛（評価する表面塗装板での測定値）−（電気亜鉛めっき鋼板の測定値）｝＞２０℃］のとき：△
［｛（評価する表面塗装板での測定値）−（電気亜鉛めっき鋼板の測定値）｝＞３０℃］のとき：×
【０１３１】
３）塗膜密着性試験
表面塗装板の熱吸収性皮膜層に、１ｍｍ角の碁盤目状の切れ目をカッターナイフで入れ、皮膜面が凸となるようにエリクセン試験機で７ｍｍ押し出した後に、テープ剥離試験を行った。
【０１３２】
碁盤目状の切れ目の入れ方、エリクセンの押し出し方法、テープ剥離の方法については、ＪＩＳ−Ｋ５４００．８．２記載の方法、及び、ＪＩＳ−Ｋ５４００．８．５記載の方法に準じて実施した。なお、本試験では同じ場所で２回続けてテープ剥離試験を実施している（以降 ２回テープ剥離と称す）。
【０１３３】
テープ剥離後の評価は、ＪＩＳ−Ｋ５４００．８．５記載の評価の例の図に従って行い、評点１０点の時に○、８点以上１０点未満の時に△、８点未満の時に×と評価した。
【０１３４】
４）塗膜の折り曲げ試験
作成した表面塗装板に１８０°折り曲げ加工を施した。そして、加工部の塗膜損傷状態をルーペにて観察し、以下の基準で評価した。折り曲げ加工は２０℃雰囲気中で、０．６ｍｍのスペーサーを間に３枚挟んで実施した（一般的に３Ｔ曲げと呼ばれる）。
【０１３５】
塗膜に全くの損傷が無い場合：○
塗膜が部分的に損傷している場合：△
塗膜が加工部全面で激しく損傷している場合：×
５）プレス成形試験
作成した表面塗装板について、油圧式エリクセンタイプのプレス加工試験機にて円筒絞り試験を行った。円筒絞り試験は、ポンチ径：５０ｍｍ、ポンチ肩Ｒ：５ｍｍ、ダイス肩Ｒ：５ｍｍ、絞り比：２．３、ＢＨＦ：１ｔの条件で行い、金属板が金型から絞り抜けるまで加工を行った。
【０１３６】
さらに、加工部の塗膜損傷状態をルーペにて観察し、下記の基準で評価した。
塗膜に全くの損傷が無い場合：○
塗膜が部分的に損傷している場合：△
塗膜が加工部全面で激しく損傷している場合：×
【０１３７】
６）耐食性
作成した表面塗装板に対し、ＪＩＳ−Ｋ５４００．９．１記載の方法で塩水噴霧試験を実施した。塩水は熱吸収性皮膜層の面に噴霧した。試験時間は１２０ｈとした。
【０１３８】
試験片表面にはカッターナイフにてクロスカットを入れた。クロスカット部の塗膜の評価方法は、クロスカット片側の最大膨れ幅が２ｍｍ未満の場合に○、２ｍｍ以上５ｍｍ未満の場合に△、５ｍｍ以上の場合に×と評価した。
【０１３９】
また、切断時の返り（バリ）が塗装鋼板の評価面側にくるように（上バリとなるように）作製した平板についても、前述の塩水噴霧試験を実施し、端面からの塗膜の膨れ幅を観察した。端面部の評価方法は端面からの膨れ幅が２ｍｍ未満の場合には○、２ｍｍ以上５ｍｍ未満の場合には△、５ｍｍ以上の場合には×と評価した。
【０１４０】
７）導電性試験
作成した表面塗装板の熱吸収性皮膜層の導電性を測定した。測定方法は、三井化学社製の抵抗率計「Ｌｏｒｅｓｔａ−ＥＰ／ＭＣＰ−Ｔ３６０」の四端子法にて表面塗装板の表面の抵抗率を測定し、以下の基準で評価した。
【０１４１】
抵抗率が０．１×１０^-2Ω未満の場合：○
抵抗率が０．１×１０^-2以上１．０×１０^-1Ω未満の場合：△
抵抗率が１．０×１０^-1Ω以上の場合：×
以下、作成した表面塗装板の評価結果を記載する。
表面塗装板に被覆された熱吸収性皮膜層の添加顔料種及び添加量の影響について評価した結果を、表５に記載する。
【０１４２】
本発明の表面塗装板（本発明例Ｉ−１〜Ｉ−１０、Ｉ−１２〜Ｉ−１３、Ｉ−１７〜Ｉ−２５）は、８０℃の温度で測定した波数６００〜３０００ｃｍ^-1の領域における全放射率が０．７０以上であることで、放射率が０．７０未満である比較例Ｉ−２６とＩ−２７より熱吸収性が高く、発熱体のカバーとして好適であることがわかる。
【０１４３】
本発明の表面塗装板の熱吸収性皮膜層は、バインダー固形分１００質量部、熱吸収性顔料１０〜１５０質量部、及び、導電性顔料１〜１５０質量部から構成されていると、加工性や導電性に優れたものとなり、より好適である。
【０１４４】
熱吸収性顔料の添加量が１０質量部未満（比較例Ｉ−２６）であると放射率が０．７未満となり、熱吸収性が劣るため不適である。熱吸収性顔料の添加量が１５０質量部超（本発明例Ｉ−５）であると放射率は高いが、折り曲げ性やプレス成形性などの加工性が低下するため、１５０質量部以下がより好適である。
【０１４５】
導電性顔料の添加量が１質量部未満（本発明例Ｉ−８）であると導電性が担保できなくなるため、１質量部以上がより好適である。導電性顔料の添加量が１５０質量部超（比較例Ｉ−２７）では、導電性顔料が熱吸収性を阻害するため、放射率が０．７未満となって熱吸収性が劣り、且つ、皮膜層の加工性も大きく低下するため不適である。
【０１４６】
本発明の表面塗装板の熱吸収性皮膜層に含まれる熱吸収性顔料が平均粒径１〜１００ｎｍのカーボンブラックで、且つ、導電性顔料が、平均粒径０．５〜５０μmのフレーク状の金属Ｎｉと鎖状の金属Ｎｉとから構成されていて、フレーク状金属Ｎｉ／鎖状金属Ｎｉの質量比が０．１〜６であると、熱吸収性と導電性により優れるためより好適である。
【０１４７】
熱吸収性顔料は、平均粒径１〜１００ｎｍのカーボンブラックがより好適である。
平均粒径０．５〜５０μmのフレーク状の金属Ｎｉと鎖状の金属Ｎｉとから構成されたものは熱吸収性を阻害しにくく好適である。しかし、フレーク状金属Ｎｉ／鎖状金属Ｎｉの質量比が０．１未満（参考例Ｉ−１１）であると導電性が低下し、質量比でフレーク状金属Ｎｉ／鎖状金属Ｎｉが６超（参考例Ｉ−１４）では、熱吸収性が阻害され放射率が低いので、フレーク状金属Ｎｉ／鎖状金属Ｎｉの質量比は０．１〜６が好適である。
【０１４８】
導電性顔料がフェロシリコン（本発明例Ｉ−１７）であると、放射率が低下せず、且つ、本発明の表面塗装板の耐食性も向上するためより好適である。
【０１４９】
また、熱吸収性顔料として導電性カーボンブラックを用いた場合、導電性が向上するためより好適である。本発明の表面塗装板の熱吸収性皮膜層中に熱吸収性顔料及び導電性顔料に加えて、防錆顔料を添加したもの（本発明例Ｉ−２２至乃Ｉ−２５）は、耐食性に優れるためより好適である。
【０１５０】
熱吸収性皮膜層の膜厚が異なる表面塗装板の評価結果を表６に記載する。膜厚が１μm未満でのもの（本発明例Ｉ−２８）は全放射率が低く、また、５０μm超では皮膜層の加工性が低下するため、膜厚は１〜５０μmがより好適である。
【０１５１】
表７に、熱吸収性皮膜層の前処理をクロメート処理にした場合（本発明例Ｉ−３５）と、前処理を施さなかった場合（本発明例Ｉ−３６）の評価結果を示す。前処理の種類を変えても放射率及び熱吸収性、他の塗膜性能に変化は無い。
【０１５２】
しかし、クロメート処理を施したものはクロメート処理皮膜中に含まれる６価クロムの環境問題が発生するため、これを含まない処理（ノンクロメート処理）の方がより好適である。
【０１５３】
また、前処理を施さなかった場合、塗膜密着性及び耐食性が低下するため、前処理を施した方がより好適である。
【０１５４】
表８に、片面のみに熱吸収性皮膜層を被覆し、他の面を未塗装とした場合の熱吸収性評価結果を示す。片面のみに熱吸収性皮膜を被覆したものは両面被覆したものより熱吸収性に劣る。
【０１５５】
片面のみ被覆した場合、熱源となる発熱体の覆うカバーの外側に熱吸収性皮膜層を施したもの（比較例Ｉ−３８）は、熱吸収性に効果が殆ど無く不適である。
【０１５６】
（実施例II）
以下、実験に用いた熱吸収性表面塗装板の作成方法について詳細を説明する。
付着量が片面当たり２０ｇ／ｍ² で両面がめっきされた厚み０．６ｍｍの電気亜鉛めっき鋼板を、市販のアルカリ脱脂剤である日本パーカライジング社製の「ＦＣ−３６４Ｓ」を２０質量％濃度に希釈した６０℃温度の水溶液中に１０秒間浸漬することで脱脂し、水洗後、乾燥した。
【０１５７】
次いで、脱脂した電気亜鉛めっき鋼板上にロールコーターにて化成処理液を塗布し、到達板温が６０℃となるような条件で熱風乾燥させた。
【０１５８】
本実験では、化成処理に市販のクロメート処理である日本パーカライジング社製の「ＺＭ１３００ＡＮ」（以下クロメート処理）と、市販のノンクロメート化成処理である日本パーカライジング社製の「ＣＴ−Ｅ３００」（以下ノンクロメート処理）を使用した。化成処理は金属板の両面にロールコーターにて処理し、到達板温６０℃の条件で乾燥した。クロメート処理の付着量は、Ｃｒ付着量で５０ｍｇ／ｍ²、ノンクロメート処理の付着量は、全皮膜量として２００ｍｇ／ｍ²とした。
【０１５９】
更に、化成処理を施した電気亜鉛めっき鋼板上の片面（以下、こちらの面をａ面と称す）に、表２に記載する吸熱皮膜塗料をロールコーターにて塗装し、熱風を併用した誘導加熱炉にて乾燥硬化させた。乾燥硬化条件は、到達板温（ＰＭＴ）で２３０℃とした。化成処理及び吸熱皮膜塗料は必要に応じて片面もしくは両面に塗装することで試験片を得た。また、他方の面（以下、こちらの面をｂ面と称す）は、未塗装のままのもの、熱吸収性塗料を塗装したもの、着色塗装を施したものを作成した。なお、着色塗装は、日本ペイント社製のプレコート鋼板用下塗り塗料「ＦＬ６４１プライマー」を乾燥膜厚で５μm塗装し、ＰＭＴ２１０℃で焼き付けたのち、更にその上に日本ペイント社製のブラックメタリック色の上塗り塗料「ＦＬ７１００」を乾燥膜厚で１５μm塗装し、ＰＭＴ２３０℃で焼き
【０１６０】
付けた。
作成した表面塗装板の詳細を表９〜１０に記載する。なお、表９〜１０中の熱吸収性塗膜の膜厚は乾燥後の膜厚である。
【０１６１】
【表１０】

【０１６２】
【表１１】

以下、作成した表面塗装板の評価試験について詳細を説明する。
１）表面塗装板の放射率測定
実施例Ｉにおけると同様であるが、本実験では作成した表面塗装板のａ面の放射率を測定した。
【０１６３】
２）表面塗装板の熱吸収性測定試験
実施例Ｉにおけると同様であるが、以下の基準で評価した。以下、温度Ａの評価基準を説明する。また、本実験では作成した表面塗装板のａ面が測定箱の内側（熱源側）となるように設置した。
［｛（電気亜鉛めっき鋼板の測定値）−（評価する表面塗装板での測定値）｝≧４℃］のとき：◎
［４℃＞｛（電気亜鉛めっき鋼板の測定値）−（評価する表面塗装板での測定値）｝≧３℃］のとき：○
［３℃＞｛（電気亜鉛めっき鋼板の測定値）−（評価する表面塗装板での測定値）｝≧２℃］のとき：△
［２℃＞｛（電気亜鉛めっき鋼板の測定値）−（評価する表面塗装板での測定値）｝］のとき：×
以下、温度Ｂの評価基準を説明する。
［２０℃≧｛（評価する表面塗装板での測定値）−（電気亜鉛めっき鋼板の測定値）｝］のとき：○
［｛（評価する表面塗装板での測定値）−（電気亜鉛めっき鋼板の測定値）｝＞２０℃］のとき：△
【０１６４】
３）塗膜密着性試験
実施例Ｉにおけると同様。ただし、本試験では、ａ面の密着性を評価した。
【０１６５】
４）塗膜の折り曲げ試験
実施例Ｉにおけると同様。但し、本試験は、ａ面側が加工部外側となるように実施し、ａ面の加工部の塗膜損傷状態を観察して、評価した。
【０１６６】
５）プレス成形試験
実施例Ｉにおけると同様。但し、本試験は、ａ面側が加工部外側となるように実施し、ａ面の加工部の塗膜損傷状態を観察して、評価した。
【０１６７】
６）耐食性
作成した表面塗装板をＪＩＳ−Ｋ５４００．９．１記載の方法で塩水噴霧試験を実施した。塩水は試験片のａ面に噴霧した。試験時間は７２ｈとした。そして、ａ面側の平面部と端面部の白錆発生状態を観察し、平面部と端面部のいずれも白錆が発生していない場合を◎、端面部に若干の白錆が発生しているが平面部には殆ど白錆が発生していない場合を○、端面部に白錆が発生し、且つ平面部にも白錆が部分的に発生している場合を△、端面部と平面部の全面に白錆が発生している場合は×と評価した。
【０１６８】
７）導電性試験
実施例Ｉにおけると同様。但し、本試験は、ａ面で実施した。
【０１６９】
８）吸熱塗料の経時の状態観察
金属板のａ面に塗装した吸熱性塗料を常温で１ヶ月放置した後の塗液の状態を目視にて観察し、次のように評価した。
【０１７０】
塗液を作成した時の状態と比べて変化無し：○
塗液を作成した時の状態と比べて粘度が増加している：△
塗液を作成した時の状態と比べて塗液がゲル状になっている、もしくは固まっている：×
【０１７１】
９）吸熱皮膜の外観
金属板上のａ面側に被覆した皮膜の外観を目視にて観察し、次のように評価した。
平滑な外観である：○
添加顔料が皮膜厚より僅かに大きいため、皮膜面表面に僅かな凹凸外観が観察される：△
【０１７２】
添加顔料が皮膜より非常に大きいため、皮膜表面に激しい凹凸外観が観察される：×
以下評価結果の詳細について述べる。
本発明の表面塗装板は、バインダー固形分１００質量部に対して粒径０．１μm未満のカーボンを１〜２０質量部と粒径０．１μm以上５０μm以下のカーボンを１〜１４０質量部含み、且つ粒径０．１μm未満のカーボンと粒径０．１μm以上５０μm以下のカーボンとの合計が１０〜１５０質量部である熱吸収性皮膜層を乾燥膜厚で１μm以上被覆することで、熱吸収性の高い表面処理粉金属板を得ることができた。
【０１７３】
本発明の表面塗装板を使い、発熱体カバーを作成する場合は、熱吸収性皮膜を発熱体カバーの内側としなければならない。本発明の吸熱皮膜を発熱体カバーの外側のみに被覆した場合（比較例II−３２）、カバー内部の温度（吸熱性温度Ａ）は殆ど低下しないため、不適である。
【０１７４】
本発明の表面塗装板の熱吸収性皮膜層で、８０℃の温度で測定した波数６００〜３０００ｃｍ^-1の領域における全放射率が０．７０未満であるもの（本発明例II−２６）は、カバー内部の温度（吸熱性：温度Ａ）が殆ど低下しないため、全放射率は０．７０以上のものが、より好適である。
【０１７５】
本発明の熱吸収性皮膜層に導電性顔料を添加した場合（本発明例II−１１）、導電性が付与されるため、発熱体カバーにアース性などを求められる用途には、より好適である。本発明の熱吸収性皮膜層に防錆顔料を添加したばあい（本発明例II−１３，II−１４）、耐食性が向上するため、耐食性が求められる用途には、よりこうてきである。さらに、耐食性と導電性の両特性を有するフェロシリコンを本発明の熱吸収性皮膜層に添加した場合（本発明例II−１２）、導電性が付与された上、耐食性も向上するため、より好適である。また、発熱体カバーの内側のみに熱吸収性皮膜を被覆して、外側には何も被覆していないものは、カバー内部の温度（吸熱性温度Ａ）は低く吸熱性に優れるが、金属板自身の温度（吸熱性温度Ｂ）は高い。そのため、発熱体カバーの内側に熱吸収性皮膜を被覆した上に、外側にも本発明の吸熱性皮膜もしくは一般に公知の着色塗膜を１０μm以上被覆した方が、より好適である。
【０１７６】
（実施例III ）
以下、実験に用いた熱吸収性表面塗装板の作成方法について詳細を説明する。
めっき付着量が片面当たり６０ｇ／ｍ² で両面がめっきされた厚み０．６mmの溶融合金化亜鉛めっき鋼板（ＧＡ）を、市販のアルカリ脱脂剤である日本パーカライジング社製の「ＦＣ−３６４Ｓ」を２０質量％濃度に希釈した６０℃温度の水溶液中に１０秒間浸漬することで脱脂し、水洗後、乾燥した。また、めっき付着量が片面当たり６０ｇ／ｍ² で両面がめっきされた厚み０．６mmのアルミめっき鋼板（アルシート）と厚み０．６mmのアルミ板（ＡＬ）を、市販のアルミ用アルカリ脱脂剤である日本パーカライジング社製の「ＦＣ−３１５」を４０質量％濃度に希釈した７０℃温度の水溶液中に１０秒間浸漬することで脱脂し、水洗後、乾燥した。
【０１７７】
次いで、脱脂しためっき鋼板およびアルミ板上にロールコーターにて化成処理液を塗布し、到達板温が６０℃となるような条件で熱風乾燥させた。
【０１７８】
本実験では、化成処理に市販のノンクロメート化成処理である日本パーカライジング社製の「ＣＴ−Ｅ３００」を使用した。化成処理は金属板の両面にロールコーターにて処理し、到達板温６０℃の条件で乾燥した。クロメート処理の付着量は、Ｃｒ付着量で５０mg／ｍ² 、ノンクロメート処理の付着量は、全皮膜量として２００mg／ｍ² とした。
【０１７９】
更に、化成処理を施しためっき鋼板上の片面（以下、こちらの面をａ面と称す）に、実施例Ｉの表１に記載の塗料１−２をロールコーターにて塗装し、熱風を併用した誘導加熱炉にて乾燥硬化させた。乾燥硬化条件は、到達板温（ＰＭＴ）で２３０℃とした。化成処理及び吸熱皮膜塗料は必要に応じて片面もしくは両面に塗装することで試験片を得た。また、他方の面（以下、こちらの面をｂ面と称す）は、着色塗装を施したものを作成した。なお、着色塗装は、日本ペイント社製のプレコート鋼板用下塗り塗料「ＦＬ６４１プライマー」を乾燥膜厚で５μｍ塗装し、ＰＭＴ２１０℃で焼き付けたのち、更にその上に日本ペイント社製のブラックメタリック色の上塗り塗料「ＦＬ７１００」を乾燥膜厚で１５μｍ塗装し、ＰＭＴ２３０℃で焼き付けた。
【０１８０】
作成した表面塗装板の詳細を表１１に記載する。なお、表１１中の熱吸収性塗膜の膜厚は乾燥後の膜厚である。
【０１８１】
【表１２】

以下、作成した表面塗装板の評価試験について詳細を説明する。
１）表面塗装板の放射率測定
実施例IIにおけると同様
２）表面塗装板の熱吸収性測定試験
実施例IIにおけると同様
３）塗膜密着性試験
実施例IIにおけると同様
４）塗膜の折り曲げ試験
実施例IIにおけると同様
５）プレス成形試験
実施例IIにおけると同様
６）耐食性
実施例IIにおけると同様
７）導電性試験
実施例IIにおけると同様
以下評価結果の詳細について述べる。
本発明の表面塗装板は、原板に溶融合金化亜鉛めっき鋼板のような鉄−亜鉛合金メッキ鋼板であると（本発明例III −１）放射率が更に高くなりより好適である。また、原板にアルミのように熱伝導性の高い材料を用いたり（本発明例III −３）、このような材料を鋼材などにめっきしたもの（本発明例III −２）は、金属板中もしくは金属板表面で熱が発散し、金属材板表面の熱が均一化されるため、より好適である。
【０１８２】
（実施例Ｖ）
以下、実験に用いた熱吸収性塗装板の作成方法について詳細に説明する。
アルミナ系のセラミックス板上に、表４に示した熱吸収性皮膜塗料をバーコーターにて塗装し、常温にて約２４時間乾燥した。作成した表面塗装板の詳細を表１５に示す。表１５に示した表面塗装板は、いずれも同じ種類の熱吸収性皮膜層を両面に同じ条件で被覆したものである。
【０１８３】
以下、作成した表面処理板の評価試験について詳細を説明する。
１）表面塗装板の放射率測定試験
実施例IVにおけると同様。
２）表面塗装板の熱吸収性測定試験
実施例IVにおけると同様。
３）塗膜の耐衝撃性試験
実施例IVにおけると同様。
４）吸熱塗料の経時の状態観察
セラミック板に塗装した各吸熱性皮膜塗料を実施例IIにおけると同様に評価した。
５）吸熱性皮膜の外観
セラミック板上に被覆した皮膜の外観を目視にて観察し、実施例IIにおけると同様に評価した。
【０１８４】
以下、作成した表面塗装板の評価結果について詳細を説明する。
表１５に示したように、本発明の表面塗装板は、樹脂固形分１００質量部に対して、粒径０．１μｍ未満のカーボンを１〜２０質量部と粒径０．１μｍ以上３０μｍ以下のカーボンを１〜１４０質量部を含み、かつ、粒径０．１μｍ未満のカーボンと粒径０．１μｍ以上５０μｍ未満のカーボンとの合計が１０〜１５０質量部である熱吸収性皮膜層を乾燥膜厚で１μｍ以上被覆することで、熱吸収性の高い表面塗装板を得ることができた。
【０１８５】
【表１３】

【０１８６】
（実施例VI）
以下、実験に用いた塗装板材料の作成方法について詳細を説明する。
板状のポリカーボネート−ＡＢＳポリマーアロイ系の樹脂（以下、プラスチック板と称する）上に、表３の塗料３−２と塗料３−２０をバーコーターにて塗装し、常温にて約２４時間乾燥した。作成した表面塗装板の詳細を表１６に示す。表１６に示した表面塗装板は、いずれも同じ種類の吸熱性皮膜層を両面に同じ条件で被覆したものである。
【０１８７】
以下、作成した表面塗装板の評価試験について詳細を説明する。
１）表面塗装板の放射率測定試験
実施例IVにおけると同様。
２）表面塗装板の熱吸収性測定試験
実施例IVにおけると同様。
３）塗膜の耐衝撃性試験
実施例IVにおけると同様。
表１６に作成した表面塗装板の評価結果を示す。本発明の表面塗装板は、母材に樹脂などのプラスチック材料を用いても熱吸収性に効果があり、好適である。
【０１８８】
【表１４】

（実施例VII ）
以下、実験に用いた熱吸収性プレコート金属板の作成方法について詳細を説明する。
厚み０．６ｍｍの金属板を、市販のアルカリ脱脂剤である日本パーカライジング社製の「ＦＣ４３３６」を２質量％濃度に希釈した６０℃温度の水溶液中にてアルカリ脱脂し、水洗後、乾燥した。次いで、脱脂した電気亜鉛めっき鋼板上にロールコーターにて化成処理液を塗布し、到達板温が６０℃となるような条件で熱風乾燥させた。
【０１８９】
本実験では次の金属板を用いた。
ＧＩ：溶融亜鉛めっき鋼板（Ｚ１２）
ＧＡ：合金化亜鉛めっき鋼板（Ｆ０８）
Ａｌシート：アルミめっき鋼板（アルミ付着量：片面６０ｇ／ｍ２）
ＳＵＳ：ステンレス鋼板（ＳＵＳ４３０、表面ブライト仕上げ）
また、本実験では、化成処理に市販のクロメート処理である日本パーカライジング社製の「ＺＭ１３００ＡＮ」（以下クロメート処理）と、市販のノンクロメート化成処理である日本パーカライジング社製の「ＣＴ−Ｅ３００」（以下ノンクロメート処理）を使用した。化成処理は金属板の両面にロールコーターにて処理し、到達板温６０℃の条件で乾燥した。クロメート処理の付着量は、Ｃｒ付着量で５０ｍｇ／ｍ²、ノンクロメート処理の付着量は、全皮膜量として２００ｍｇ／ｍ²とした。
【０１９０】
更に、化成処理を施した金属板上の片面（以下、こちらの面をａ面と称す）に、先に作成した表１及び２より選出した塗料をロールコーターにて塗装し、熱風を併用した誘導加熱炉にて乾燥硬化させた。乾燥硬化条件は、到達板温（ＰＭＴ）で２３０℃とした。また、他方の面（以下、こちらの面をｂ面と称す）は、着色塗料もしくはクリヤー塗料をロールコーターにて塗装した。なお、着色塗装は、日本ペイント社製のプレコート鋼板用下塗り塗料「ＦＬ６４１プライマー」を乾燥膜厚で５μmロールコーターにて塗装し、ＰＭＴ２１０℃で焼き付けたのち、更にその上に日本ペイント社製の白色上塗り塗料「ＦＬ３５１０」を乾燥膜厚で１５μmロールコーターにて塗装し、ＰＭＴ２３０℃で焼き付けた。また、クリヤー塗料は、日本ペイント社製のＦＬ５０００クリヤーを３μm塗装した。なお、本実験で用いた着色塗膜層のプライマー塗料「ＦＬ６４１プライマー」は、クロメート処理を施した金属板上に塗装する場合には、ストロンチウムクロメートを樹脂固形分に対して４８質量％添加したクロメートタイプのものを用い、ノンクロメート処理を施した金属板上に塗装する場合には、カルシウムシリケートを３０質量％添加したノンクロメートタイプのものを用いた。
【０１９１】
作成したプレコート金属板の詳細を表１７に記載する。なお、表１７中の熱吸収性塗膜の膜厚は乾燥後の膜厚である。
【０１９２】
以下、実験に用いた冷蔵庫の作成方法について詳細を記載する。
市販の小型冷蔵庫の金属外板を取り外した。次に、取り外した金属板と同じ形状に切断、加工した前記プレコート金属板を、プレコート金属板のａ面が冷蔵庫の内側となるようにして取り付けることで冷蔵庫を作成した。
【０１９３】
以下、作成した表面塗装板の評価試験について詳細を説明する。
１）冷蔵庫外板の放射率測定
日本分光社製のフーリエ変換赤外分光光度計「ＶＡＬＯＲ−III 」を用いて、冷蔵庫外板に用いるために作成したプレコート金属板の板温度を８０℃にしたときの波数６００〜３０００ｃｍ^-1の領域における赤外発光スペクトルを測定し、これを標準黒体の発光スペクトルと比較することで、属板の全放射率を測定した。なお、標準黒体は鉄板にタコスジャパン社販売（オキツモ社製造）の「ＴＨＩ−１Ｂ黒体スプレー」を３０±２μmの膜厚でスプレー塗装したものを用いた。
【０１９４】
また、放射率の測定は、作成したプレコート金属板のａ面を測定した。
２）冷蔵庫内部の温度測定試験
作成した冷蔵庫の電源を入れ、通常の条件で運転させ、運転開始２４ｈ後の内部の主熱源であるモーター付近の温度を、デジタル温度にて測定した。なお、温度は、モーターから５ｃｍ離れた箇所の温度を測定した。
【０１９５】
更に、市販の冷蔵庫に元々取り付けてあった従来の金属外板（従来金属外板）を取り付けた状態の冷蔵庫内部の温度を前述した条件下で測定し、これと評価する冷蔵庫の想定温度とを比較して、以下の様に評価した。
【０１９６】
以下、冷蔵庫内部の温度の評価基準を説明する。
［｛（従来金属外板を有する冷蔵庫の測定値）−（評価する冷蔵庫での測定値）｝≧４℃］のとき：○
［４℃＞｛（従来金属外板を有する冷蔵庫の測定値）−（評価する冷蔵庫での測定値）｝≧２℃］のとき：△
［２℃＞｛（従来金属外板を有する冷蔵庫の測定値）−（評価する冷蔵庫での測定値）｝］のとき：×
【０１９７】
３）冷蔵庫外板の皮膜密着性試験
冷蔵庫外板用に作成したプレコート金属板のａ面の皮膜層に、１ｍｍ角の碁盤目状の切れ目をカッターナイフで入れ、ａ面が凸となるようにエリクセン試験機で７ｍｍ押し出した後に、テープ剥離試験を行った。
碁盤目状の切れ目の入れ方、エリクセンの押し出し方法、テープ剥離の方法については、ＪＩＳ−Ｋ５４００．８．２記載の方法、及び、ＪＩＳ−Ｋ５４００．８．５記載の方法に準じて実施した。
テープ剥離後の評価は、ＪＩＳ−Ｋ５４００．８．５記載の評価の例の図に従って行い、評点１０点の時に○、８点以上１０点未満の時に△、８点未満の時に×と評価した。
【０１９８】
４）冷蔵庫外板の加工性
作成したプレコート金属板を冷蔵庫の外板に加工した際に、ａ面側加工部の皮膜の損傷状態を目視にて観察して、次のように評価した。
【０１９９】
加工部で皮膜の亀裂や剥離が無く良好な外観である：○
加工部の皮膜に小さな亀裂と剥離が発生している：△
加工部でほぼ全面的に皮膜が剥離している：×
５）冷蔵庫外板の耐食性
冷蔵庫外板用に作成したプレコート金属板をＪＩＳ−Ｋ５４００．９．１記載の方法で塩水噴霧試験を実施した。塩水は試験片のａ面に噴霧した。試験時間は４８ｈとした。そして、ａ面側の平面部の白錆発生状態を観察し、平面部から白錆が発生していない場合を○、平面部に白錆は発生しているが赤錆は発生していない場合を△、平面部にも白錆と赤錆が発生している場合を×と評価した。
【０２００】
６）冷蔵庫外板の導電性試験
冷蔵庫外板用に作成したプレコート鋼板のａ面の導電性を測定した。測定方法は、三井化学社製の抵抗率計「Ｌｏｒｅｓｔａ−ＥＰ／ＭＣＰ−Ｔ３６０」の四端子法にて金属板の表面の抵抗率を測定し、以下の基準で評価した。
【０２０１】
抵抗率が０．１×１０^-2Ω未満の場合：○
抵抗率が０．１×１０^-2以上１．０×１０^-1Ω未満の場合：△
抵抗率が１．０×１０^-1Ω以上の場合：×
７)熱吸収性皮膜塗料の粘度経時変化調査試験
本実験で用いた熱吸収性塗料（表１及び２から選出した塗料）を有機溶剤（ソルベッソ１５０とシクロヘキサノンとを質量比で１：１に混合したもの）で希釈し、全固形分濃度（Ｎ．Ｖ．）を５０質量％となるように調整した。
【０２０２】
そして、作成した塗料の初期粘度をＪＩＳ．Ｋ５４００．４．５．４に記載のフォードカップＮｏ．４法にて測定した。更に、これらの塗料を１週間常温で放置した後に攪拌機にて再攪拌した後の粘度を１週間後の粘度として再度前記のフォードカップＮｏ．４法にて測定した。そして、１週間放置前後の粘度を比較して、作成した各塗料の粘度上昇を以下のように評価した。なお、粘度経時変化試験の評価結果は、表１８に記載する。
【０２０３】
［（１週間後の粘度）−（初期粘度）］＜２０秒のとき：〇
２０≦［（１週間後の粘度）−（初期粘度）］＜５０秒のとき：△
［（１週間後の粘度）−（初期粘度）］≧５０秒のとき：×
【０２０４】
【表１５】

【０２０５】
【表１６】

【０２０６】
本発明の冷蔵庫外板に被覆する熱吸収性皮膜にはバインダー固形分１００質量部に対してカーボンを１０〜１５０質量部含むと熱吸収性皮膜の放射率が０．７０以上となり好適である。カーボンの添加量が１０未満のもの（比較例−VII −１５，VII −１６，VII −１８）や被覆していないもの（比較例VII −１９）は、放射率が０．７０未満となり不適である。また、カーボンの添加量が１５０質量部超のもの（比較例VII −１７）は加工性に劣るため、不適である。
【０２０７】
本発明の冷蔵庫外板の熱吸収性皮膜には導電性顔料を添加したものは導電性が付与されるため、冷蔵庫組立時に静電気が発生しにくく、静電気起因の塵や埃の付着問題がなく、より好適である。導電性顔料を添加しない場合（参考例VII −６，VII −８，VII −９）は、導電性が劣っている。
【０２０８】
本発明の冷蔵庫外板の熱吸収性皮膜には防錆顔料を添加したもの（本発明例VII −７，参考例VII −８，VII −９）は耐食性に優れ、より好適である。特にフェロシリコンを添加したもの（本発明例VII −７）は耐食性に加えて導電性にも優れるため、より好適である。
【０２１０】
本発明の冷蔵庫外板には熱吸収性皮膜を塗装する前に化成処理を施すと、密着性や加工性に優れ、より好適である。化成処理を施していないもの（本発明例VII −１２）は密着性や加工性に劣っている。更に、化成処理の種類は、いずれでも良いが、クロメート処理を用いたもの（本発明例VII −１１）よりはノンクロメート処理を施したものの方が、環境問題の点から、より好適である。
【０２１１】
（実施例VIII）
以下、実験に用いた熱吸収性塗装板の作成方法について詳細に説明する。
アルミ合金板及びマグネシウム合金板の内面に、表４に示した熱吸収性皮膜塗料をバーコーターにて塗装し、常温にて約２４時間乾燥した。作成した表面塗装板の詳細を表１９（Ａｌ合金板）及び表２０（Ｍｇ合金板）に示す。表１９及び表２０に示した表面塗装板は、いずれも同じ種類の熱吸収性皮膜層を両面に同じ条件で被覆したものである。
【０２１２】
以下、作成した表面処理板の評価試験について詳細を説明する。
１）表面塗装板材料の放射率測定
実施例IVにおけると同様
２）表面塗装板材料の熱吸収性測定試験
実施例IVにおけると同様
３）塗膜の耐衝撃性試験
実施例IVにおけると同様
４）吸熱塗料の経時の状態観察
アルミ合金板及びマグネシウム合金板上に塗装した各吸熱性皮膜塗料を実施例IIにおけると同様に評価した。
【０２１３】
５）吸熱性皮膜の外観
アルミ合金板及びマグネシウム合金板上に被覆した皮膜の外観を目視にて観察し、実施例IIにおけると同様に評価した。
【０２１４】
以下、作成した表面塗装板の評価結果について詳細を説明する。
表１９及び表２０に示したように、本発明の表面塗装板は、樹脂固形分１００質量部に対して、粒径０．１μｍ未満のカーボンを１〜２０質量部と粒径０．１μｍ以上５０μｍ以下のカーボンを１〜１４０質量部を含み、かつ、粒径０．１μｍ未満のカーボンと粒径０．１μｍ以上５０μｍ以下のカーボンとの合計が１０〜１５０質量部である熱吸収性皮膜層を乾燥膜厚で１μｍ以上被覆することで、熱吸収性の高い表面塗装板を得ることができた。
【０２１５】
【表１７】

【０２１６】
【表１８】

（実施例IX）
以下、実験に用いた塗装板材料の作成方法について詳細を説明する。
板状のポリカーボネート−ＡＢＳポリマーアロイ系の樹脂（以下、プラスチック板と称する）上に、表４の塗料４−２と塗料４−９をバーコーターにて塗装し、常温にて約２４時間乾燥した。作成した表面塗装板の詳細を表２１に示す。表２１に示した表面塗装板は、いずれも同じ種類の吸熱成否膜層を両面に同じ条件で被覆したものである。
【０２１７】
以下、作成した表面塗装板の評価試験について詳細を説明する。
１）表面塗装板の放射率測定試験
実施例IVおけると同様。
２）表面塗装板の熱吸収性測定試験
実施例IVにおけると同様。
３）塗膜の耐衝撃性試験
実施例IVにおけると同様。
表２１に作成した表面塗装板の評価結果を示す。本発明の表面塗装板は、母材に樹脂などのプラスチック材料を用いても熱吸収性に効果があり、好適である。
【０２１８】
【表１９】

（実施例Ｘ）
以下、実験に用いた熱吸収性アルミ合金板の作成方法について詳細を説明する。
０．６ｍｍのアルミ合金板を、市販のアルカリ脱脂剤である日本パーカライジング社製の「ＦＣ−３１５」を２０質量％濃度に希釈した６０℃温度の水溶液中に１０秒間浸漬することで脱脂し、水洗後、乾燥した。更にその上に市販のノンクロメート処理である日本パーカライジング社製の「ＣＴＥ−３００」を乾燥付着量にして２００ｍｇ／ｍ²ロールコーターにて塗装した。
【０２１９】
次いで、脱脂したアルミ合金板上に、表１に記載する熱吸収性皮膜塗料をロールコーターにて塗装し、熱風を併用した誘導加熱炉にて乾燥硬化させた。乾燥硬化条件は、到達板温（ＰＭＴ）で２３０℃とした。熱吸収性皮膜塗料は必要に応じて片面もしくは両面に塗装することで試験片を得た。
【０２２０】
作成した表面処理アルミ合金板の詳細を表２２に記載する。表２２中記載のアルミ合金板は、いずれも、片面のみに熱吸収性皮膜層を被覆し、他の面は被覆していないものである。
【０２２１】
【表２０】

【０２２２】
以下、作成したアルミ合金板の評価試験について詳細を説明する。
１）アルミ合金板の放射率測定
実施例Ｉと同じ。
２）アルミ合金板の熱吸収性測定試験
実施例IVと同じ。
３）塗膜密着性試験
実施例Ｉと同じ。
４）塗膜の折り曲げ試験
実施例Ｉと同じ。
５）プレス成形試験
実施例Ｉと同じ。
６）耐食性
作成したアルミ合金板に対し、ＪＩＳ−Ｋ５４００．９．１記載の方法で塩水噴霧試験を実施した。塩水は熱吸収性皮膜層の面に噴霧した。試験時間は５００ｈとした。
【０２２３】
クロスカット部の塗膜の評価方法は、クロスカット片側の最大膨れ幅が２ｍｍ未満の場合に○、２ｍｍ以上５ｍｍ未満の場合に△、５ｍｍ以上の場合に×と評価した。
【０２２４】
また、切断時の返り（バリ）が塗装鋼板の評価面側にくるように（上バリとなるように）作製した平板についても、前述の塩水噴霧試験を実施し、端面からの塗膜の膨れ幅を観察した。端面部の評価方法は端面からの膨れ幅が２ｍｍ未満の場合には○、２ｍｍ以上５ｍｍ未満の場合には△、５ｍｍ以上の場合には×と評価した。
【０２２５】
７）導電性試験
実施例Ｉと同じ。
アルミ合金板に被覆された熱吸収性皮膜層の添加顔料種及び添加量の影響について評価した結果を、表２２に記載する。
【０２２６】
本発明のアルミ合金板（本発明例Ｘ−１〜Ｘ−１０、Ｘ−１２、Ｘ−１３、Ｘ−１７〜Ｘ−２５）は、８０℃の温度で測定した波数６００〜３０００ｃｍ^-1の領域における全放射率が０．７０以上であることで、放射率が０．７０未満である比較例Ｘ−２６とＸ−２７より熱吸収性が高く、発熱体のケースとして好適であることがわかる。
【０２２７】
本発明のアルミ合金板の熱吸収性皮膜層は、バインダー固形分１００質量部、熱吸収性顔料１０〜１５０質量部、及び、導電性顔料１〜１５０質量部から構成されていると、加工性や導電性に優れたものとなり、より好適である。
【０２２８】
熱吸収性顔料の添加量が１０質量部未満（比較例Ｘ−２６）であると放射率が０．７未満となり、熱吸収性が劣るため不適である。熱吸収性顔料の添加量が１５０質量部超（本発明例Ｘ−５）であると放射率は高いが、折り曲げ性やプレス成形性などの加工性が低下するため、１５０質量部以下がより好適である。
【０２２９】
導電性顔料の添加量が１質量部未満（本発明例Ｘ−８）であると導電性が担保できなくなるため、１質量部以上がより好適である。導電性顔料の添加量が１５０質量部超（比較例Ｘ−２７）では、導電性顔料が熱吸収性を阻害するため、放射率が０．７未満となって熱吸収性が劣り、且つ、皮膜層の加工性も大きく低下するため不適である。
【０２３０】
本発明のアルミ合金板の熱吸収性皮膜層に含まれる熱吸収性顔料が平均粒径１〜１００ｎｍのカーボンブラックで、且つ、導電性顔料が、平均粒径０．５〜５０μmのフレーク状の金属Ｎｉと鎖状の金属Ｎｉとから構成されていて、フレーク状金属Ｎｉ／鎖状金属Ｎｉの質量比が０．１〜６であると、熱吸収性と導電性により優れるためより好適である。
【０２３１】
熱吸収性顔料が炭パウダーや黒鉛パウダーのように粒径が比較的大きなもの（本発明Ｘ−６及びＸ−７）では、放射率が比較的低く、且つ、導電性顔料の導電効果を大きな熱吸収性顔料が阻害し導電性も低下するため、熱吸収性顔料は、平均粒径１〜１００ｎｍのカーボンブラックがより好適である。
【０２３２】
本発明のアルミ合金板の熱吸収性皮膜層に含まれる導電性顔料がアルミ粉やステンレス粉であると、これらの導電性顔料が熱吸収性を阻害し易く、これらを添加したもの（参考例Ｘ−１５及びＸ−１６）は放射率が低下する。
【０２３３】
平均粒径０．５〜５０μmのフレーク状の金属Ｎｉと鎖状の金属Ｎｉとから構成されたものは熱吸収性を阻害しにくく好適である。しかし、フレーク状金属Ｎｉ／鎖状金属Ｎｉの質量比が０．１未満（参考例Ｘ−１１）であると導電性が低下し、質量比でフレーク状金属Ｎｉ／鎖状金属Ｎｉが６超（参考例Ｘ−１４）では、熱吸収性が阻害され放射率が低いので、フレーク状金属Ｎｉ／鎖状金属Ｎｉの質量比は０．１〜６が好適である。
【０２３４】
導電性顔料がフェロシリコン（本発明例Ｘ−１７）であると、放射率が低下せず、且つ、本発明のアルミ合金板の耐食性も向上するためより好適である。熱吸収性顔料を添加せずにフェロシリコンのみを添加したもの（本発明例Ｘ−１９）は、放射率が比較的高く、且つ、導電性や耐食性に優れるため好適である。
【０２３５】
また、熱吸収性顔料として導電性カーボンブラックを用いた場合、導電性が向上するためより好適である。本発明のアルミ合金板の熱吸収性皮膜層中に熱吸収性顔料及び導電性顔料に加えて、防錆顔料を添加したもの（本発明例Ｘ−２２至乃Ｘ−２５）は、耐食性に優れるためより好適である。
【０２３６】
熱吸収性皮膜層の膜厚が異なるアルミ合金板の評価結果を表７に記載する。膜厚が１μm未満でのもの（本発明例Ｘ−２８）は全放射率が低く、また、５０μm超では皮膜層の加工性が低下するため、膜厚は１〜５０μmがより好適である。
【０２３７】
【図面の簡単な説明】
【図１】 図１は本発明の熱吸収性に優れた発熱体カバー又はケースの構成を示す図である。
【図２】 図２は熱吸収性を測定する測定箱の態様を示す図である。[0001]
BACKGROUND OF THE INVENTION
  The present invention relates to a product excellent in heat absorption, and in particular, metallic and non-metallic covers having components that generate heat, such as motors, electronic components, heaters, and batteries, and materials for the covers. It relates to a surface-treated metal plate. Further, the present invention provides a refrigerator with high thermal efficiency using such a material having excellent heat absorption, a portable device (mobile device) or an in-vehicle device in which a high endothermic paint is applied to the inside of the case to suppress the temperature rise, and its Also related to the case. Examples of portable devices or in-vehicle devices include mobile phones, notebook computers, PDAs, in-vehicle battery cases, car navigation systems, car audio devices, and in-vehicle control devices.
[0002]
[Prior art]
  Conventionally, metal plates such as steel plates and aluminum plates have been used as cover materials for outer plates and internal parts of home appliances, but such metal plates are required to have performance such as corrosion resistance and design properties. For this reason, it is common to use it after surface treatment. Examples of such a metal plate include a galvanized steel plate excellent in corrosion resistance, a galvanized steel plate coated with a chromate treatment, and a pre-coated metal plate that has been previously coated to impart design properties.
[0003]
  Further, there are additional required performances for these metal plates, such as fingerprint resistance, grounding property, and scratch resistance, and various surface-treated steel plates have been developed to satisfy these performances.
[0004]
  For example, in Japanese Patent Publication No. 4-14191, an organic composite film in which a colloidal sol having a specific fine particle size is additionally adjusted to a water-based organic resin is formed on a chromate-coated plated steel sheet, thereby improving corrosion resistance and fingerprint resistance. Techniques for making them disclosed are disclosed. Japanese Patent Laid-Open No. 5-65666 discloses a technique for improving the work galling property by coating a plated steel sheet with a paint containing a wax and a lubricant, and Japanese Patent Laid-Open No. 10-16128 A technique for imparting fingerprint resistance and grounding properties by coating a metal surface that has been chromated with a film with controlled surface roughness and film thickness is disclosed.
[0005]
  In addition, non-metallic materials such as plastics are also used for the cover material of the outer plates and internal parts of home appliances. However, in this case as well, in recent years, with the spread of computers and the digitization of household appliances, many parts that become heat sources such as motors and electronic components have been used inside these computers and household appliances, Since the heat generation amount of these heat sources is also increasing, the cover material for product outer plates and internal parts has been required to have the property of suppressing the heat generated inside or the property of efficiently radiating the heat. . On the other hand, a heating element cover for home appliances or the like is also required to have conductivity for grounding.
[0006]
  Conventionally, in order to suppress the temperature rise inside the electronic device incorporating the electronic component, considering heat dissipation, the electronic component is provided with a heat radiation fin, the electronic device case is provided with a heat radiation opening, For example, forced cooling with a fan is performed inside electronic equipment.
[0007]
  Electronic devices are vulnerable to heat, and when the temperature rises, malfunctions and performance degradation occur, so heat dissipation and cooling are important. Recently, with higher integration and finer wiring, countermeasures against performance degradation such as malfunction due to temperature rise and slow operation speed are becoming more important. In particular, in portable devices (mobile devices), which are small electronic devices, and in-vehicle devices that are used outdoors and exposed to heat from engines, etc., the built-in heat-generating electronic components and the self-heating of the battery store heat in the device case. Therefore, it is a very important issue to suppress the temperature rise of electronic devices and batteries.
[0008]
  Conventionally, with regard to heat dissipation of electronic equipment cases, the main technology has been to form openings for high heat or to form cases with highly heat-conducting materials. A method of applying a high paint is also proposed.
[0009]
  As a prior art close to the present invention, Japanese Patent Application Laid-Open No. 11-340639 discloses that a coating film containing an infrared absorber is applied to the inner surface side of a casing of an electronic device including a portable information device in addition to a TV receiver. Has been.
[0010]
  Various methods for cooling and heat dissipation of electronic devices have been proposed and adopted as described above, but in portable devices or in-vehicle devices, the material of the case is often restricted due to aesthetics, lightness, etc. Further, more efficient cooling and heat dissipation are required for miniaturization and higher performance.
[0011]
[Problems to be solved by the invention]
  The first object of the present invention is to develop a technology for imparting excellent heat absorption to metallic and non-metallic heating element covers and surface-treated metal plates based on the above requirements, and to make a metal made with excellent heat absorption. And a non-metallic heating element cover and a surface-treated metal plate.
[0012]
  The second object of the present invention is related to the first object described above, is to develop a technology that imparts excellent heat absorption to the outer plate, and a refrigerator excellent in heat efficiency, and a refrigerator excellent in heat absorption. It is providing the manufacturing method which manufactures efficiently.
[0013]
  A third object of the present invention is to provide a case with improved heat dissipation in a portable device or an in-vehicle device incorporating a heat generating electronic component, and to provide a portable device or an in-vehicle device having such a case. It is in.
[0014]
[Means for Solving the Problems]
  As a result of intensive studies, the inventors applied a highly heat-absorbing substance to the inner surface of a heat source cover made of metal and non-metal such as home appliances, and did not apply a highly heat-absorbing substance. In comparison, it has been found that the temperature inside the heat source cover decreases.
[0015]
  The present invention has been completed based on such findings, and the gist thereof is as follows.
  (1) A wave number of 600 to 3000 cm measured at a temperature of 80 ° C. or higher and 200 ° C. or lower on at least the inner surface of the heating element cover main body.^-1A heat-absorbing coating layer having a total emissivity of 0.70 or more in the region is coated with 100 mass parts of binder solids, andAs a heat absorbing pigment,1 to 20 parts by mass of carbon having a particle size of less than 0.1 μm and 1 to 140 parts by mass of carbon having a particle size of 0.1 to 50 μm, and carbon having a particle size of less than 0.1 μm and a particle size of 0.1 to 50 μm A heating element cover excellent in heat absorption, characterized in that the total of the following carbon is 10 to 150 parts by mass.
  (2)AboveThe heat-absorbing coating layer has a binder solid content of 100 parts by mass and a heat-absorbing pigment of 10 to 150 parts by mass.WithFurthermore, 1 to 150 parts by mass of a conductive pigmentincludingThe heating element cover having excellent heat absorption as described in (1).
  (3) The heat-absorbing pigment is carbon black having an average particle diameter of 1 to 100 nm, and the conductive pigment is composed of flaky metal Ni and chain metal Ni having an average particle diameter of 0.5 to 50 μm. The heating element cover having excellent heat absorption characteristics according to (2), wherein the cover has a mass ratio of flaky metal Ni / chain metal Ni of 0.1 to 6.
  (4) The heating element cover having excellent heat absorption according to any one of (2) to (3), wherein the conductive pigment is ferrosilicon.
  (5) The heating element cover according to any one of (1) to (4), wherein the heating element cover body is made of metal.
  (6) The heating element cover according to any one of (1) to (4), wherein the heating element cover body is made of non-metal.
  (7) Wave number 600 to 3000 cm measured at a temperature of 80 ° C. or higher and 200 ° C. or lower on at least one side of a metal plate or a plated metal plate.^-1A heat-absorbing coating layer having a total emissivity of 0.70 or more in the region is coated with 100 mass parts of binder solids, andAs a heat absorbing pigment,1 to 20 parts by mass of carbon having a particle size of less than 0.1 μm and 1 to 140 parts by mass of carbon having a particle size of 0.1 to 50 μm, and carbon having a particle size of less than 0.1 μm and a particle size of 0.1 to 50 μm The surface treatment metal plate excellent in heat absorption characterized by the total of the following carbon being 10-150 mass parts.
  (8)AboveThe heat-absorbing coating layer has a binder solid content of 100 parts by mass and a heat-absorbing pigment of 10 to 150 parts by mass.WithFurthermore, 1 to 150 parts by mass of conductive pigmentincludingThe surface-treated metal plate excellent in heat absorption as described in (7).
  (9) The heat-absorbing pigment is carbon black having an average particle diameter of 1 to 100 nm, and the conductive pigment is composed of flaky metal Ni and chain metal Ni having an average particle diameter of 0.5 to 50 μm. The surface-treated metal plate having an excellent heat absorption property according to (8), wherein the surface-treated metal plate is configured and has a mass ratio of flaky metal Ni / chain metal Ni of 0.1 to 6.
  (10) The surface-treated metal plate excellent in heat absorption according to any one of (8) to (9), wherein the conductive pigment is ferrosilicon.
    (11) The surface-treated metal plate excellent in heat absorbability according to any one of claims 7 to 10, wherein the heat-absorbent film has a thickness of 1 to 50 µm.
  (12) Wave number 600-3000 cm measured at a temperature of 80 ° C. or more and 200 ° C. or less^-1A heat-absorbing film having a total emissivity of 0.70 or more in the region is coated on the inner surface of the outer plate, and the heat-absorbing film is 100 parts by mass of the binder solid content.As a heat-absorbing pigment1 to 20 parts by mass of carbon having a particle size of less than 0.1 μm and 1 to 140 parts by mass of carbon having a particle size of 0.1 to 50 μm, and carbon having a particle size of less than 0.1 μm and a particle size of 0.1 to 50 μm Less than carbon and 10 to 150 parts by mass, and conductiveAs a pigment1 to 50 parts by mass of metal powder, and having a dry film thickness of 1 μm or more, a refrigerator with excellent thermal efficiency.
(13) Characterized by coating a clear coating or a coating containing a colored pigment on the outside of the outer plate (12) Which is excellent in thermal efficiency.
  (14) Having a heat-absorbing coating layer on the inside of a case of a portable device or an in-vehicle device containing a heat generating electronic component,
(A) For 100 parts by mass of binder solid contentAs a heat-absorbing pigment1 to 20 parts by mass of carbon having a particle size of less than 0.1 μm and 1 to 140 parts by mass of carbon having a particle size of 0.1 to 50 μm, and carbon having a particle size of less than 0.1 μm and a particle size of 0.1 to 50 μm 10 to 150 parts by mass in total with carbon
(B) Carbon black having a binder solid content of 100 parts by weight, a heat absorbing pigment of 10 to 150 parts by weight, and a conductive pigment of 1 to 150 parts by weight, wherein the heat absorbing pigment has an average particle diameter of 1 to 100 nm The conductive pigment is composed of flaky metal Ni having an average particle size of 0.5 to 50 μm and chain metal Ni, and the mass ratio of flaky metal Ni / chain metal Ni is 0.1 to 6;
(C) It is comprised from 100 mass parts of binder solid content, 10-150 mass parts of heat-absorbing pigments, and 5-150 mass parts of ferrosilicon.
(D) Consists of 100 parts by weight of binder solids and 5 to 150 parts by weight of ferrosilicon
A portable device or a vehicle-mounted device, which is any of the above.
  (15(2) A portable device or a vehicle-mounted device, wherein the case of the portable device or the vehicle-mounted device containing a heat generating electronic component is the heating element cover according to any one of (1) to (6).
  (16) Cases of portable devices or in-vehicle devices containing electronic components that generate heat are (7) to (7)11A portable device or an in-vehicle device, which is obtained by processing the surface-treated metal plate according to any one of (1) above, and has a heat-absorbing film layer of the metal plate as an inner surface.
  (17) The case is made of Mg alloy or Al alloy (14) ~ (16EitherCrabThe portable device or in-vehicle device described.
  (18) (14A case for a portable device or a vehicle-mounted device having the heat-absorbing film layer described in (1).
  (19) At least one side of the metal plate or plated metal plateIn advanceWave number 600-3000 cm measured at a temperature of 80 ° C. or higher and 200 ° C. or lower^-1A heat-absorbing coating layer having a total emissivity of 0.70 or more in the region ofA pre-coated surface-treated metal plate that is then moldedThe heat-absorbing coating layer has a binder solid content of 100 parts by mass, a carbon black having an average particle diameter of 1 to 100 nm as a heat-absorbing pigment, and 10 to 150 parts by mass of metal Ni as a conductive pigment. ComposedThe metal Ni is composed of flaky metal Ni having an average particle size of 0.5 to 50 μm and chain metal Ni, and the mass ratio of flaky metal Ni / chain metal Ni is 0.1. ~ 6A pre-coated surface-treated metal plate excellent in heat absorption.
  (20) The heat absorbing film layerInCarbon blackBut10-15 parts by massIs(19) Precoated surface-treated metal sheet with excellent heat absorption.
(21) The mass ratio of the flaky metal Ni / chain metal Ni is 6 (20A precoated surface-treated metal plate having excellent heat absorption as described in (1).
  (22) Wave number 600-3000 cm measured at a temperature of 80 ° C. or more and 200 ° C. or less on at least one side of a metal plate or a plated metal plate^-1A heat-absorbing film layer having a total emissivity of 0.70 or more in the region of the above is coated, and the heat-absorbing film layer has a binder solid content of 100 parts by mass, and an average particle diameter of 1 to 100 nm as a heat-absorbing pigment. 10 to 150 parts by mass of carbon black, and 1 to 150 parts by mass of ferrosilicon as a conductive pigment.
  (23(7) to (10) or (7), wherein the heat absorbing film has a thickness of 1 to 50 μm.19) ~ (22) Precoated surface-treated metal plate with excellent heat absorption.
  (24) (19) ~ (23The precoated surface-treated metal sheet according to claim 1 is molded and processed so that the surface having the heat-absorbing film is at least the inner surface of the cover. Body cover.
[0016]
【The invention's effect】
  According to the present invention, a technology for releasing heat generated inside a home electric appliance in which many parts serving as heat sources such as motors and electronic parts are used is established. Furthermore, it has become possible to provide a surface treatment material that is suitable for releasing heat and has excellent conductivity for grounding home appliances. By using this technology, it has become possible to further improve the performance of home appliances including refrigerators and reduce energy consumption. Similarly, the present invention also includes a mobile phone, a notebook computer, a PDA, an in-vehicle battery case, a car navigation system, a car audio device, an in-vehicle control device, etc. in which the temperature inside the device rises because it contains electronic parts and a battery. The technology is applied and has effects such as improved performance and reduced energy consumption, and is an invention with high industrial applicability. Therefore, it can be said that the present invention is an industrially extremely valuable invention.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
  (Metal and non-metallic heating element covers and surface-treated metal plates)
  In the present invention, the heating element can be any component that generates heat, such as a motor, an electronic component, a heater, and a battery, and is not particularly limited. The heating element cover is used for the purpose of covering, enclosing, and housing such a heating element.
[0018]
  Hereinafter, the heat-absorbing heating element cover of the present invention will be described mainly based on a heating element cover made of a metal plate. However, the present invention is not limited to this, and is similarly applied to a non-metallic heating element cover. It is.
[0019]
  It is known that heat is a part of electromagnetic waves that diverge from an object, and when thermal radiation is incident on an object, part is reflected, part is transmitted, and the rest is absorbed (for example, Nishikawa, Co-authored by Fujita, “Basic Course of Mechanical Engineering, Electrical and Thermal Engineering”, p.289, published by Science and Engineering (1983)).
[0020]
  When thermal radiation is incident on a metal plate, a surface-treated metal plate, or a non-metallic material, the thermal radiation is hardly transmitted, so that the thermal radiation is reflected or absorbed.
[0021]
  Here, when the thermal radiation generated from the heating element is incident on the inner surface of the heating element cover, if much of the incident thermal radiation is reflected, the heat is generated inside the heating element cover, and the temperature inside the cover is reduced. To rise.
[0022]
  Therefore, in order to reduce the temperature inside the heat source cover, it is necessary to suppress the reflection of thermal radiation inside the cover, but as a result of earnest research, the present inventors have found that the inside of the cover has a highly heat-absorbing film. It was found that the reflection of thermal radiation can be suppressed by coating with a layer.
[0023]
  As a method for examining the absorption rate of thermal radiation incident on the surface of a metal plate or non-metal material, the reflection method using an infrared spectrophotometer is well known, but when measuring by this method, a metal plate or non-metal material is used. If the surface roughness is rough, the incident thermal radiation is irregularly reflected, so that it is difficult to obtain an accurate absorption rate.
[0024]
  According to Kirchhoff's law for thermal radiation, the absorptivity and emissivity of an object are the same at a constant temperature (for example, Nishikawa and Fujita, “Basic Course of Mechanical Engineering, Electrical and Thermal Engineering”, p. 290, published by Science and Engineering). (1983)).
[0025]
  As a result of intensive studies based on this knowledge, the present inventors have found that at least one surface of a metal plate or a plated metal plate has a wave number of 600 to 3000 cm measured at a temperature of 80 ° C. or more and 200 ° C. or less.^-1A surface-treated metal plate pre-coated with a heat-absorbing film layer having a total emissivity of 0.70 or more in the region of is molded so that the surface coated with the heat-absorbing film layer is inside the cover of the heating element It was found that when the heating element was covered with the cover produced in this manner, the temperature inside the cover was lower than when the cover was made with a cover made of a metal plate not coated with the heat absorbing film on the inner surface of the cover. Similarly, a wave number of 600 to 3000 cm measured at a temperature of 80 ° C. or higher and 200 ° C. or lower on the inner surface of the cover made of a nonmetallic material.^-1If the heating element is covered with a cover that has a heat-absorbing film layer with a total emissivity of 0.70 or more in the area of the area, the temperature inside the cover is the cover that does not cover the inner surface of the cover with the heat-absorbing film. It has also been found that it is lower than when covering.
[0026]
  600 cm frequency^-1Less than or 3000cm^-1Since the radiation absorption in the super wave number region has a very low temperature lowering effect in the cover, the emissivity including radiation in these wave number regions is unsuitable. Also, wave number 600-3000cm^-1When a heat-absorbing film layer having a total emissivity of less than 0.70 is coated, the temperature lowering effect in the cover is small, which is not suitable.
[0027]
  FIG. 1 shows the configuration of a metallic or non-metallic heating element cover excellent in heat absorption according to the present invention. The metal or non-metal heating element cover of the present invention is composed of a metal plate or non-metal material 1 and has an inner surface covered with a heat-absorbing coating layer 2. In the figure, 3 is a heating element. If the heat-absorbing coating layer 2 is previously coated on a flat metal plate or a non-metallic material and then processed to create a metal or non-metal heating element cover, it is preferable because the working efficiency is improved in the production. .
[0028]
  Moreover, if the surface which coat | covered the metal plate or the heat absorbing film layer of a nonmetallic material does not comprise the inner surface of a heat generating body cover, the temperature fall effect in a heat generating body cover will not be acquired. The heat absorbing film layer may be coated not only on the inner surface of the heating element cover but also on the outer side. When the outer side is also coated, the temperature of the metallic or non-metallic heating element cover itself is lowered by the influence of thermal radiation equivalent to heat absorption, which is more preferable.
[0029]
  The metal plate and the non-metal material constituting the metal and non-metal heating element cover excellent in heat absorption of the present invention are a metal plate, a plated metal plate or a non-metal material in order to ensure heat absorption. The wave number of 600 to 3000 cm measured at a temperature of 80 ° C. or more and 200 ° C. or less, comprising at least one side of: a) 100 parts by mass of binder solid content, and b) 10 to 150 parts by mass of the heat-absorbing pigment.^-1This is achieved by coating a heat-absorbing coating layer having a total emissivity of 0.70 or more in the region.
[0030]
  Carbon as a heat absorbing pigmentTheMessengerfor,Commercially available products may be used. During ~However, since carbon black has a very small particle size and is widely dispersed in the film, it is a suitable pigment, and in particular, one having a particle size of 1 to 100 nm is preferable.
[0031]
  The present inventors further added carbon to the coating layer in order to increase the total emissivity of the coating layer coated with a metal plate or a non-metallic material and improve the heat absorption property. It has been found that it is preferable to conceal a plate or non-metallic material. In addition, generally well-known carbon, such as a carbon rack, charcoal, graphite, can be used with carbon here. In order to conceal a metal plate or non-metallic material with carbon, it is necessary to add a large amount of carbon having a smaller particle diameter. Even if a small amount of carbon having a small particle diameter is added, the concealing effect is small, and in the case of carbon having a large particle diameter, a gap is generated between carbon and carbon even if a large amount of carbon is added. However, when a large amount of carbon having a small particle size is added, the viscosity of the coating liquid containing the binder solid and carbon increases, and the workability of the coating deteriorates. Fine-particle carbon dispersed in the coating liquid aggregates over time. As a result, problems such as gelation of the coating liquid occur. In order to solve these problems, the inventors have intensively researched and found that the above problem can be solved by using together carbon having a small particle size of less than 0.1 μm and carbon having a large particle size of 0.1 μm or more and 50 μm or less. I found out that it would be resolved. By using these together, the fine carbon is dispersed in the gaps between the large carbon particles dispersed in the film, so that the metal plate and non-metal material can be concealed by carbon without adding a large amount of fine carbon. The heat absorption effect is exhibited.
[0032]
  In a preferred embodiment of the present invention obtained from this finding, the heat-absorbing film layer (hereinafter referred to as endothermic film) has an added amount of carbon of 0.1 μm in particle size with respect to 100 parts by mass of binder solid content. Less than 1 to 20 parts by mass of carbon and 1 to 140 parts by mass of carbon having a particle size of 0.1 μm or more and 50 μm or less, and fine carbon having a particle size of less than 0.1 μm and a particle size of 0.1 to 50 μm The total of the particle size carbon is 10 to 150 parts by mass, and the film thickness of the endothermic coating layer is 1 μm or more. The lower limit of the particle size of the fine carbon is not particularly specified, but if it exceeds 0.1 μm, a gap is likely to be formed between the carbon and the carbon, and it is not suitable because it does not exhibit the role as the fine carbon. If the amount of fine carbon added is less than 1 part by mass, it is inadequate because the concealing effect of the metal plate or non-metallic material is poor and the heat absorption is inferior, and if it exceeds 20 parts by mass, the viscosity of the coating liquid becomes high. It is not suitable because it becomes gel-like over time. If the particle size of the large particle size carbon is less than 0.1 μm, the role as the large particle size carbon is not exhibited, and the same behavior as that of the fine particle carbon is exhibited. If the particle size of the large particle size carbon is more than 50 μm, it is not suitable because the coating property is lowered when the coating liquid containing this is applied, or the appearance of the coated film is deteriorated. The particle size of the large particle size carbon is preferably 0.1 μm or more and 30 μm or less. More preferably, it is 0.1 μm or more and 10 μm or less. If the amount of carbon having a large particle size is less than 1 part by mass, the heat absorption is inferior, and if it exceeds 140 parts by mass, the film becomes brittle and the processability of the film is inferior. Furthermore, if the total addition amount of the fine particle carbon and the large particle size carbon is less than 10 parts by mass, the heat absorption is inferior, and if it exceeds 150 parts by mass, the film becomes brittle and the processability of the film is inferior. It is unsuitable because the coating workability is inferior. When the film thickness of the endothermic film is less than 1 μm, the heat absorption property of the film is inferior.
[0033]
  In one preferred embodiment, the metal plate or the non-metal material constituting the metal or non-metal heating element cover having excellent heat absorption according to the present invention is a metal plate or a metal plate in order to ensure heat absorption and conductivity. In addition to a) 100 parts by mass of binder solid content and b) 10 to 150 parts by mass of heat-absorbing pigment, c) 1 to 150 parts by mass of conductive pigment on at least one side of the plated metal plate or non-metallic material Wave number of 600 to 3000 cm measured at a temperature of 80 ° C. or higher and 200 ° C. or lower.^-1This is achieved by coating a heat-absorbing coating layer having a total emissivity of 0.70 or more in the region.
[0034]
  As the conductive pigment, flaky metal Ni, chain metal Ni etc.MessengerUseCommercially available products may be used. MoneyThe genus generally tends to reflect heat and tends to inhibit the heat absorption of the heat absorbing pigment. Metal Ni has a property that it is difficult to inhibit heat absorption of the heat-absorbing pigment as compared to other metal pigments, and chain metal Ni has a chain shape, so the area that reflects heat in the film is small, Hard to inhibit heat absorptionGoodIs suitable.
[0035]
  However, since the chain metal Ni alone is inferior in conductivity, it is preferable to use a combination of the flake metal Ni and the chain metal Ni. In this case, it is more preferable that the mass ratio of flaky metal Ni / chain metal Ni is 0.1 to 6 because heat absorption and conductivity are excellent.
[0036]
  The flaky metal Ni has a large area for reflecting heat in the film, and thus tends to inhibit heat absorption. Therefore, if the mass ratio of flaky metal Ni / chain metal Ni is less than 0.1, the conductivity is inferior, whereas if it exceeds 6, the heat absorbability is inferior.
[0037]
  Furthermore, when the conductive pigment is ferrosilicon, the emissivity of the heat-absorbing coating layer is improved, and in the case of a surface-treated metal plate, the corrosion resistance is also improved. Ferrosilicon is excellent not only in conductivity but also in heat absorption, and can serve as both conductive pigment and heat absorption pigment, so even if added alone, both heat absorption and conductivity properties are secured. be able to.
[0038]
  When the amount of the heat-absorbing pigment added relative to 100 parts by mass of the binder solid content is less than 10 parts by mass, the wave number of 600 to 3000 cm measured at a temperature of 80 ° C. or more and 200 ° C. or less.^-1The total emissivity of the metal plate in the region is less than 0.70, which is not suitable.
[0039]
  The higher the amount of the heat-absorbing pigment added relative to 100 parts by mass of the resin solids, the higher the emissivity and the more preferable. However, if it exceeds 150 parts by mass, the coating layer becomes brittle and the impact resistance of the coating layer decreases. Therefore, the workability at the time of processing the metal plate is deteriorated, which is not suitable.
[0040]
  The film thickness of the heat-absorbing coating layer can be arbitrarily selected as necessary, but is preferably 1 to 50 μm for a metal plate and 1 to 1000 μm for a nonmetallic material. If it is less than 1 μm, the wave number measured at a temperature of 80 ° C. or higher and 200 ° C. or lower is 600 to 3000 cm.^-1The total emissivity of the metal plate or non-metallic material in the region is less than 0.70. In the case of a metal plate, if it exceeds 50 μm, the processability of the coating layer is lowered, which is not suitable. On the other hand, if it is more than 1000 μm, the heat absorption is saturated and is not economically meaningful. In consideration of conductivity, 1 μm or more and less than 10 μm is more preferable.
[0041]
  As the binder constituting the heat-absorbing coating layer of the present invention, generally known coating binders such as an inorganic coating formed by a resin or a sol-gel method or an inorganic organic composite coating formed by a sol-gel method can be used. . It is preferable to use the resin in the form of a paint from the viewpoint of easy handling and film formation.
[0042]
  As the resin, generally known ones such as polyester resin, urethane resin, acrylic resin, epoxy resin, melamine resin, vinyl chloride resin can be used, and any type of thermoplastic type or thermosetting type can be used. Also good.
[0043]
  These resins may be used in combination of several kinds as required. These resins are not particularly specified because the film performance, such as processability, work adhesion, and film hardness, also varies depending on the type, the molecular weight of the resin, and the glass transition temperature Tg of the resin. It is necessary to select appropriately.
[0044]
  In addition, the type of resin that is cured using a cross-linking agent depends on the type and addition amount of the cross-linking agent and the type and amount of catalyst added during the cross-linking reaction. Since hardness etc. differ, it does not prescribe | regulate in particular, It is necessary to select suitably as needed.
[0045]
  These resins can be used by melting a solid one by heat, dissolving it in an organic solvent, or pulverizing it into a powder. Further, it may be water-soluble or water-dispersed emulsion type. Furthermore, an ultraviolet (UV) curing type or an electron beam (EB) curing type may be used. Any of these commercially available types can be used.
[0046]
  According to the knowledge obtained by the present inventors so far, solvent-based melamine curable polyester systems, solvent-based isocyanate curable polyester systems, water-dispersed acrylic emulsions and the like are suitable. Is preferred. However, these are examples, and the present invention is not limited to these.
[0047]
  In the case of a solvent-based melamine curable polyester system, the molecular weight of the polyester resin is preferably 2000 to 30000 in number average molecular weight, the Tg of the polyester resin is preferably −10 to 70 ° C., and the addition amount of the melamine resin is The amount is preferably 5 to 70 parts by mass with respect to 100 parts by mass of the polyester resin.
[0048]
  If the molecular weight of the polyester resin is less than 2000, the processability of the film is lowered, and if it exceeds 30000, the viscosity is too high when the resin is dissolved in a solvent, which is not suitable. When the Tg of the polyester resin is less than −10 ° C., the film is not suitable because it does not form a film, and when it exceeds 70 ° C., the film is too hard, so that the workability is lowered and unsuitable. If the addition amount of the melamine resin is less than 5 parts by mass with respect to 100 parts by mass of the polyester, the film is uncured and unsuitable, and if it exceeds 70 parts by mass, the film becomes too hard and the workability deteriorates. It is.
[0049]
  As the polyester resin to be used, commercially available ones such as “Byron” manufactured by Toyobo Co., Ltd., “Desmophen” manufactured by Sumika Bayer Ureethane, etc. can be used. As the melamine resin to be used, commercially available products such as “Cymel” and “My Coat” manufactured by Mitsui Cytec Co., Ltd., “Beckamine” and “Super Beckamine” manufactured by Dainippon Ink & Chemicals, Inc. may be used. it can.
[0050]
  In the case of a solvent-based isocyanate-curable polyester system, the molecular weight of the polyester resin is preferably 2000 to 30000 in terms of number average molecular weight, the Tg of the polyester resin is preferably -10 to 70 ° C, and the amount of isocyanate added is [NCO group equivalent of isocyanate] / [OH group equivalent of polyester resin] = 0.8 to 1.2 is preferable.
[0051]
  When the value of [NCO group equivalent of isocyanate] / [OH group equivalent of polyester resin] is less than 0.8 or more than 1.2, the film tends to be uncured during film formation. If the molecular weight of the polyester resin is less than 2000, the processability of the film is lowered, and if it exceeds 30000, the viscosity is too high when the resin is dissolved in a solvent, which is not suitable. If the Tg of the polyester resin is less than −10 ° C., the film is not suitable because it does not form a film, and if it exceeds 70 ° C., the film is too hard and unsuitable because the workability decreases.
[0052]
  As the polyester resin to be used, commercially available products such as “Byron” manufactured by Toyobo Co., Ltd. and “Desmophen” manufactured by Sumika Bayer Urethane Co., Ltd. can be used.
[0053]
  As the isocyanate to be used, those commercially available, for example, “Sumijoule”, “Desmodur” manufactured by Sumika Bayer, “Takenate” manufactured by Mitsui Takeda Chemical Co., Ltd. and the like can be used.
[0054]
  In addition, a water-dispersed acrylic emulsion type can be generally used and may be a commercially available one. The water-dispersed acrylic emulsion type may be used after adding a resin having good adhesion such as a generally known epoxy resin.
[0055]
  Since the kind and addition amount of the epoxy resin are affected by the performance of the coating film, they can be appropriately selected as necessary. In the case of water-based resins such as water-dispersed acrylic resins, coating workability is high and there is no problem of atmospheric release of volatile organic solvents. Equipment is not necessary, which is more suitable.
[0056]
  In the heat-absorbing coating layer of the present invention, in addition to the heat-absorbing pigment and the conductive pigment, a color pigment, an antirust pigment and an antirust agent can be added in combination as necessary.
[0057]
  Examples of coloring pigments include titanium oxide (TiO₂ ), Zinc oxide (ZnO), zirconium oxide (ZrO)₂ ), Calcium carbonate (CaCO_Three ), Barium sulfate (BaSO)_Four ), Alumina (Al₂O_Three ), Kaolin clay, carbon black, iron oxide (Fe₂O_Three , Fe_ThreeO_Four In general, known inorganic pigments such as inorganic pigments and organic pigments can be used.
[0058]
  As for the rust preventive pigment, generally known chromium rust preventive pigments such as strontium chromate and calcium chromate, zinc phosphate, zinc phosphite, aluminum phosphate, aluminum phosphite, molybdate, and molybdenum phosphate. Commonly known non-chromium rust preventive pigments and rust preventives such as acid salts, vanadic acid / phosphoric acid mixed pigments, silica, and a type of silica adsorbed with Ca called calcium silicate can be used.
[0059]
  In particular, when the base material of the metal plate of the present invention is a metal that is easily corroded, such as a steel plate or a plated steel plate, the corrosion resistance of the metal plate of the present invention is improved by adding a rust preventive pigment and a rust preventive agent. Therefore, it is more preferable.
[0060]
  In consideration of environmental problems in recent years, non-chromium rust preventive pigments and rust preventives are more effective. For these non-chromium rust preventive pigments and rust preventive agents, reagents may be used or commercially available ones may be used.
[0061]
    Commercially available rust preventive pigments include zinc phosphate rust preventive pigments “EXPERT-NP500” and “EXPERT-NP530” manufactured by Toho Pigment Co., and zinc phosphite rust preventive pigments “EXPERT-” manufactured by Toho Pigment Co., Ltd. “NP1500”, “EXPERT-NP1530”, “EXPERT-NP1600”, “EXPERT-NP1700”, aluminum tripolyphosphate “K-WHITE series” manufactured by Teika, molybdate pigments and phosphoric acid molybdic acid manufactured by SHERWIN Williams Salt pigment “SHER-WHITE series”, Nippon Aerosil Co., Ltd. and Degussa gas phase silica “AEROSIL series”, Nissan Chemical Co., Ltd. colloidal silica “Snowtex series”, GRACE Ca adsorption type silica “Sealdex” -Series "etc.
[0062]
  These color pigments, rust preventive pigments, and rust preventives are selected appropriately as needed because other film properties such as emissivity, workability, appearance, and corrosion resistance vary greatly depending on the type, amount added, and particle size. There is a need.
[0063]
  In addition, generally known leveling agents, pigment dispersants, waxes and the like can be added to the heat-absorbing coating layer of the present invention as necessary. The type and amount of these additives are not particularly defined and can be appropriately selected as necessary. In particular, the wax is effective for improving the formability when the surface-treated metal plate of the present invention is formed and for preventing the heat-absorbing coating layer from being scratched.
[0064]
  In order to form the heat-absorbing coating layer of the present invention on the surface of a metal plate or on the surface of a non-metallic material, a coating component containing a binder can be generally applied in the form of a known paint. For example, the paint forms include a solvent-based paint obtained by dissolving a resin in a solvent, an aqueous paint obtained by dispersing an emulsified resin in water, a powder paint obtained by pulverizing a resin, and a resin obtained by pulverizing and powdering water. There are slurry powder coatings dispersed in, ultraviolet (UV) curable coatings, electron beam (EB) curable coatings, film laminates in which the resin is applied in the form of a film, and forms after the resin is melted. .
[0065]
  The coating method is not particularly limited, and generally known coating methods such as roll coating, roller curtain coating, curtain flow coating, air spray coating, airless spray coating, brush coating, and die coater coating can be employed. . Moreover, immersion coating, inkjet coating, etc. may be used.
[0066]
  In addition, it is preferable to pre-treat the metal plate before coating the metal plate with the heat-absorbing coating layer in order to improve the film adhesion of the metal plate. When this pretreatment is performed, the adhesion of the heat-absorbing film and the corrosion resistance of the metal plate are improved, which is more preferable.
[0067]
  Even if the pretreatment for coating is not performed, it is more preferable that the coating pretreatment step can be omitted if the coating film adheres. As the pretreatment for coating, generally known ones such as coating chromate treatment, electrolytic chromate treatment, zinc phosphate treatment, zirconia treatment, and titania treatment can be used.
[0068]
  In recent years, a non-chromate pretreatment based on an organic compound such as a resin has been developed. However, using a non-chromate pretreatment based on a resin is more preferable because it reduces the burden on the environment. .
[0069]
  Examples of non-chromate pretreatments based on organic compounds such as resins include JP 09-828291 A, JP 10-251509 A, JP 10-337530 A, JP 2000-17466 A, Examples include the techniques described in JP 2000-248385 A, JP 2000-273659 A, JP 2000-282252 A, JP 2000-265282 A, JP 2000-167482 A, and the like. However, other than the above, generally known techniques can be used.
[0070]
  A commercially available non-chromate treatment may be used. The adhesiveness of the heat-absorbing film layer and the corrosion resistance of the metal plate vary greatly depending on the kind of these pretreatments and the amount of adhesion, so it is necessary to select them as necessary.
[0071]
  Since the metal plate of the present invention is intended to be processed to produce a metal heating element cover, any metal material that can be processed may be used, and generally known metal materials can be used. The metal material may be an alloy material. For example, steel, aluminum, titanium, copper, a magnesium alloy, etc. are mentioned. In particular, the use of a metal having high thermal conductivity such as aluminum or copper is preferable because the absorbed heat is uniformly dispersed in the metal, so that the metal can be prevented from being locally heated. Moreover, the surface of these materials may be plated.
[0072]
  Examples of the type of plating include zinc plating, aluminum plating, copper plating, nickel plating and the like. Alloy plating may be used. In the case of steel sheets, generally known steel sheets such as cold-rolled steel sheets, hot-rolled steel sheets, hot-dip galvanized steel sheets, electrogalvanized steel sheets, hot-dip galvanized steel sheets, aluminum-plated steel sheets, aluminum-zinc alloyed steel sheets, stainless steel sheets, etc. And plated steel plate can be applied.
[0073]
  However, iron-zinc alloy-plated steel sheet, like the galvannealed steel sheet, has high heat absorbability itself, so if it is coated with a heat-absorbing film, the heat-absorbability is further improved. Is preferable. In addition, when a heat-absorbing film is coated on a steel plate plated with a metal with high thermal conductivity such as aluminum or copper, the absorbed heat is uniformly dispersed through the plating layer on the metal surface, so that the metal can be prevented from becoming locally hot. Therefore, it is more preferable. Steel plates plated with metals with high thermal conductivity such as aluminum and copper not only improve thermal conductivity, but also have the strength and formability of steel plates, and metals with high thermal conductivity such as aluminum and copper. Is cheaper than using a simple substance, and thus the manufacturing cost can be reduced, which is more preferable.
[0074]
  These metal plates can be subjected to ordinary treatments such as hot water washing, alkaline degreasing, and pickling before the pretreatment for coating. A generally known processing method can be used as a processing method for manufacturing a metal heating element cover by molding a metal. For example, processing methods such as forging, casting, punching, bending, drawing, overhanging, and roll forming can be used. In addition, a pre-coating method in which a heat-absorbing coating layer is previously coated on a metal plate and then molded is preferable because of high production efficiency.
[0075]
  Non-metallic materials used in the present invention are all inorganic materials and organic materials except metallic materials, but may be natural materials such as plastics, resins, ceramics, ceramics, cement, and the like. In addition, as the resin, generally known resins such as acrylic resins, vinyl chloride resins, HIPS resins, ABS resins, and polycarbonate resins can be used. As the ceramic, generally known ceramics such as alumina, aluminum nitride, barium titanate, strontium titanate and the like can be used.
[0076]
  In the case of non-metallic materials, if necessary, the surface of the non-metallic material that covers the heat-absorbing film is generally subjected to a known chemical conversion treatment or roughened so that the heat-absorbing film is adhered. It can also improve the performance.
[0077]
  Examples of the use of the heating element cover excellent in heat absorption and the material therefor according to the present invention include VTR, audio equipment, DVD, television, liquid crystal television, plasma display, plasma display tuner and other audiovisual equipment and their surroundings General household appliances such as equipment, personal computer peripherals such as personal computers, notebook computers, optical disk drives, and hard disk drives, mobile devices such as mobile phones and electronic notepads, refrigerators, air conditioner outdoor units, air conditioner indoor units, washing machines, lighting fixtures, Battery cases, in-vehicle battery cases, in-vehicle electronic component equipment, car navigation systems, car audio equipment, vending machines, money changers, ticket machines such as prepaid cards and tickets, etc. External part cover , The effect is exhibited by using the present invention product in the inner and outer control apparatus cover.
[0078]
  Details of the refrigerator, portable device, and in-vehicle device, which have been confirmed by the inventors using the heating element cover excellent in heat absorption and the material therefor, which are products of the present invention, will be described below.
[0079]
  (refrigerator)
  There are many heat source components such as motors and electronic components inside the refrigerator. Particularly in recent years, electronic computerization of refrigerators has progressed, and heat generated from these heat sources accumulates inside the refrigerator, and the internal temperature tends to rise. As the temperature inside the refrigerator rises, more power is required to lower the temperature in the refrigerator compartment, and this shortens the life of the motor and electronic components. However, in recent years, from the viewpoint of ecology, there is an increasing demand for a reduction in power consumption for electric products such as refrigerators.
[0080]
  As a result of intensive studies, the present inventors have found that when a highly heat-absorbing substance is applied to the surface of the metal material on the inner side of the refrigerator outer plate, a heat source such as a motor is produced compared to a case where no highly heat-absorbing substance is applied. We found that the temperature in the vicinity decreased.
[0081]
  The heating element cover and the heat-absorbing film described above are explained in detail when the outer plate constituting the refrigerator is regarded as the heating element cover, and the heat-absorbing film is directly coated on the outer plate and the inner surface of the refrigerator according to the present invention. Since this explanation is appropriate, further explanation is omitted here.
[0082]
  In the refrigerator of the present invention, the structure and the inside of the refrigerator may be the same as a known one except that the inner surface of the outer plate is coated with a specific heat absorbing film.
[0083]
  The outer surface of the refrigerator outer plate of the present invention is more preferable because it can be given a design appearance when it is coated with a colored coating or a clear coating. This colored coating layer or clear coating layer is a multilayer coating, and the bottom layer is a rust-preventing coating layer containing a rust-preventing pigment, and the layer above this is used as a coloring layer containing a coloring pigment. Accordingly, it is more preferable to further coat the clear coating on the metal plate because the corrosion resistance is improved and the design property is increased in the case of a metal plate.
[0084]
  Also, in the process of assembling the refrigerator, static electricity is generated on the surface film of the metal plate used for the outer plate of the refrigerator due to friction with the belt conveyor and other transport devices, and dust and dust in the assembly line adhere to the surface of the metal plate. Will occur. In order to solve this problem, it is necessary to release the static electricity accumulated on the surface of the coating by imparting conductivity to the coating. In addition to the carbon, the heat-absorbing coating layer coated on the inside of the refrigerator outer plate of the present invention contains 1 to 50 parts by weight of conductive metal powder with respect to 100 parts by weight of binder solid content. The problem of adhesion of dust and dust caused by static electricity in the refrigerator assembly process is solved, which is more preferable. The configuration for imparting conductivity to the heat-absorbing coating layer was also described above.
[0085]
  When manufacturing the refrigerator of the present invention, pre-coated metal plate with high heat absorption by coating the heat absorbing film layer of the present invention on one side of a flat metal plate in advance, after cutting and processing this, It is more preferable to assemble in a refrigerator so that the heat-absorbing coating layer is on the inner side of the outer plate because the working efficiency is increased.
[0086]
  When producing the refrigerator of the present invention, a pre-coated metal plate that has been previously coated with a heat-absorbing film is manufactured, and then a processing method for cutting, processing, and assembling is generally a known processing method. it can. For example, processing methods such as punching, bending, drawing, overhanging, roll forming and the like can be mentioned.
[0087]
  (Mobile devices and in-vehicle devices)
  The present invention has been found that by applying the highly heat-absorbing paint of the present invention to the inner surface side of an electronic device case containing a heat generating electronic component or battery, the temperature rise inside the electronic device can be remarkably suppressed. is there.
[0088]
  In the present invention, portable devices (mobile devices) and in-vehicle devices are not particularly limited, and include mobile phones, notebook computers, PDAs, in-vehicle batteries, car navigation system devices, car audio devices, in-vehicle control devices, and the like.
[0089]
  The electronic component that generates heat is not particularly limited, and refers to electronic components such as a CPU element, an MPU element, a DSP element, an electronic integrated circuit, and a resistor. A generally known battery can also be applied.
[0090]
  The material constituting the case of the portable device or the in-vehicle device of the present invention is not particularly limited, and examples include an Mg alloy case, an Al alloy case, a steel plate case, other metal cases, a plastic case, etc. This is particularly useful in the case of an Al alloy case and a steel plate case.
[0091]
  In one embodiment, the heat-absorbing coating layer of the case of the portable device or the vehicle-mounted device of the present invention has 1 to 20 parts by mass of carbon having a particle size of less than 0.1 μm and 0 to a particle size of 0 with respect to 100 parts by mass of the binder solid content. .1 to 140 parts by mass of carbon of 1 μm or more and 50 μm or less is included, and the total of carbon having a particle size of less than 0.1 μm and carbon having a particle size of 0.1 to 50 μm is 10 to 150 parts by mass.
[0092]
  In the second aspect, the heat-absorbing coating layer is composed of 100 parts by weight of binder solids, 10 to 150 parts by weight of heat-absorbing pigment, and 1 to 150 parts by weight of conductive pigment. Is a carbon black having an average particle diameter of 1 to 100 nm, and the conductive pigment is composed of flaky metal Ni and chain metal Ni having an average particle diameter of 0.5 to 50 μm, and flaky metal Ni / chain The mass ratio of metal Ni is 0.1-6.
[0093]
  In the third aspect, the heat-absorbing coating layer is composed of 10 to 150 parts by mass of a heat-absorbing pigment and 10 to 150 parts by mass of ferrosilicon with respect to 100 parts by mass of the binder solid content.
[0095]
  The specific contents of the heat-absorbing coating layer in each of these aspects are basically the same as described above for the heating element cover. Therefore, a specific description is omitted here. Further, the heating element cover described above may be used as a case of a portable device or an in-vehicle device.
[0096]
  In order to form the highly endothermic coating layer of the present invention on the case surface, a coating component containing a binder can be generally applied in the form of a known paint. For example, the paint forms include a solvent-based paint obtained by dissolving a resin in a solvent, an aqueous paint obtained by dispersing an emulsified resin in water, a powder paint obtained by pulverizing a resin, and a resin obtained by pulverizing and powdering water. There are slurry powder coatings, ultraviolet (UV) curable coatings, electron beam (EB) curable coatings, film laminating with resin on the film, and application after melting the resin. .
[0097]
  The film thickness of the high heat absorption film is preferably 1 to 1000 μm. If the film is less than 1 μm, the heat absorbability of the film is inferior, which is not suitable. If the film is more than 1000 μm, the heat absorption is saturated and it does not make economic sense, so it is not suitable. More preferably, it is 10-500 micrometers. In order to ensure conductivity, the thickness is more preferably 1 μm or more and less than 10 μm.
[0098]
  The high endothermic coating layer of the present invention is generally applied to the surface after the case is formed, but in the case of a plate material, it may be applied before forming.
[0099]
  In the present invention, the temperature inside the electronic device and the battery case is lowered because the surface coated with the endothermic coating layer is inside the case of the electronic component or battery that generates heat.
[0100]
  The structure of the case excellent in heat absorption of the present invention may be the same as that shown in FIG. The case of the present invention is composed of, for example, an Mg alloy plate 1 and is characterized in that the inner surface is covered with a superabsorbent coating layer 2. In the figure, reference numeral 3 denotes a heat generating electronic component or a battery.
[0101]
  Moreover, if the surface which coat | covered the high heat absorption film layer is not the inner surface of a case, the temperature fall effect in an electronic device case will not be acquired. However, in addition to the inner surface of the case, the high heat absorption coating layer may be coated on the outer side. If it is also coated on the outside, it is easier to release the heat absorbed in the metal plate, which is a heating element case, due to the effect of heat radiation equivalent to heat absorption. is there.
[0102]
  Further, a colored appearance may be coated on the outside of the case to give a design appearance. The colored coating layer may be a multi-layer coating, and in the case of metal, the lowermost layer may include a rust-preventing coating layer containing a rust-preventing pigment, and the layer above this may be used as a colored layer containing a coloring pigment. In these cases, the colored organic coating layer (including the anti-corrosion coating layer in the case of a multilayer coating) has a certain degree of thermal radiation, so if it covers a total of 10 μm or more, the temperature of the case decreases. Therefore, it is more preferable.
[0103]
【Example】
  Hereinafter, the details of the method for producing the heat-absorbing coating material used in the experiment will be described.
  “Byron GK140” (number average molecular weight: 13000, Tg 20 ° C.) manufactured by Toyobo Co., Ltd., which is a commercially available organic solvent soluble type / amorphous polyester resin (hereinafter referred to as a polyester resin), was dissolved in an organic solvent (Solvesso 150 and cyclohexanone). In a mass ratio of 1: 1).
[0104]
  Next, 15 parts by mass of Cymel 303 manufactured by Mitsui Cytec, which is a commercially available hexa-methoxy-methylated melamine, is added to the polyester resin dissolved in the organic solvent with respect to 100 parts by mass of the solid content of the polyester resin. By adding 0.5 parts by mass of “Catalyst 6003B” manufactured by Mitsui Cytec Co., Ltd., which is an acidic catalyst, and stirring, a melamine curable polyester-based clear paint (hereinafter referred to as polyester / melamine system) was obtained.
[0105]
  In addition, in order to see the influence of the resin, “Sumidur BL3175” manufactured by Sumika Bayer Urethane Co., Ltd., which is a commercially available blocked isocyanate based on HDI, is added to the polyester resin dissolved in the organic solvent. Group equivalent] / [OH group equivalent of polyester resin] = 1.0, and further, 0.05% of Mitsui Takeda Chemical's reaction catalyst “TK-1” is added to the resin solid content. Thus, an isocyanate-curable polyester-based clear coating (hereinafter referred to as polyester / isocyanate-based) was obtained.
[0106]
  Furthermore, a commercially available water-dispersed acrylic emulsion type resin was prepared, and a commercially available water-soluble epoxy resin was added to the solid content in an amount of 5% by mass to prepare a water-dispersed acrylic emulsion / epoxy clear coating ( Hereinafter referred to as water-based acrylic).
[0107]
  Furthermore, a commercially available room temperature drying solvent-based clear coating (hereinafter referred to as solvent-based normal drying) and a commercially available room-temperature drying water-based clear coating (hereinafter referred to as aqueous normal drying) were prepared.
[0108]
  Next, a heat-absorbing pigment, a conductive pigment, and a rust-preventing pigment were added to the prepared and prepared clear coating as necessary, and a heat-absorbing coating was obtained by stirring. Details of the paints prepared are listed in Tables 1-4.
[0109]
[Table 1]

[0110]
[Table 2]

[0111]
[Table 3]

[0112]
[Table 4]

[0113]
[Table 5]

[0114]
  In Tables 1 to 4, the notes (* 1) to (* 19) are as follows.
(* 1): part by mass of additive pigment with respect to 100 parts by mass of resin solids in the paint
(* 2): Uses “Toka Black # 7350F” manufactured by Tokai Carbon Co., Ltd. (28 nm / particulate carbon)
(* 3): Uses “Binchotan Charcoal Powder” manufactured by the cooperative Lest (maximum particle size: 5 μm / large particle size carbon A)
(* 4): The graphite powder of the reagent is further pulverized, and the average particle size is 10 μm using a sieving classifier.
(* 5) “Toka Black # 5500F” manufactured by Tokai Carbon Co., Ltd. is used (particle size: 25 nm)
(* 6): Commercially available flaky metal Ni and chain metal Ni were obtained and mixed so that flake Ni / chain Ni = 6 by mass ratio (average particle size: 5 μm)
(* 7): Commercially available flaky metal Ni and chain metal Ni were obtained and mixed so that flake Ni / chain Ni = 1 by mass ratio (average particle size: 5 μm)
(* 8): Commercially available flaky metal Ni and chain metal Ni were obtained and mixed so that flake Ni / chain Ni = 0.1 by mass ratio (average particle size: 5 μm)
(* 9): “Aluminum powder 02-0005” manufactured by Toyo Aluminum Co., Ltd. (average particle size: 10 μm)
(* 10): Use commercially available stainless steel powder (average particle size: 20 μm)
(* 11): Ferrosilicon No. 2 described in JIS-G2302 is pulverized with a pulverizer, and an average particle size of 10 μm is used with a sieving classifier.
(* 12): Commercially available flaky metal Ni and chain metal Ni were obtained and mixed so that flake Ni / chain Ni = 0.05 by mass ratio (average particle size: 5 μm)
(* 13): Commercially available flaky metal Ni and chain metal Ni were obtained and mixed so that flake Ni / chain Ni = 7 by mass ratio (average particle size: 5 μm)
(* 14): “AEROSIL300” manufactured by Nippon Aerosil Co., Ltd. is used (12 nm)
(* 15): Uses “Sealdex C303” manufactured by Grace (3 μm)
(* 16): “K-WHITE K-105” manufactured by Teika Co., Ltd. is used (average particle size: 2.3 μm)
(* 17): “Snowtex N” manufactured by Nissan Chemical Co., Ltd. is used.
(* 18): “AF Black U14” manufactured by Dainichi Seikagaku Kogyo Co., Ltd. is used. (This rust preventive pigment is a resin-dispersed water-dispersed type. (Diameter: 10-50 nm)
(* 19): Titanium oxide “Taipeke CR95” manufactured by Ishihara Sangyo Co., Ltd. is used.
(* 20): The graphite powder of the reagent is further pulverized, and the average particle size is 40 μm using a sieving classifier (large particle size carbon B)
(* 21): The graphite powder of the reagent is further pulverized, and the average particle size is 60 μm using a sieving classifier (large particle size carbon C)
[0115]
  In addition, all the binders in Tables 1 to 4 are normally dry solvent systems.
  Hereinafter, details of the embodiment will be described in detail.
[0116]
  Example I
  Hereafter, the detail is demonstrated about the preparation method of the heat absorptive surface coating board used for experiment.
  Adhesion amount is 20g / m per side² 10 mm in an aqueous solution at a temperature of 60 ° C. obtained by diluting “FC-364S” manufactured by Nippon Parkerizing Co., Ltd., which is a commercially available alkaline degreasing agent, to a concentration of 20% by mass. It was degreased by dipping for 2 seconds, washed with water and dried.
[0117]
  Next, a pretreatment liquid was applied on the degreased electrogalvanized steel sheet with a roll coater, and dried with hot air under conditions such that the ultimate plate temperature was 60 ° C.
[0118]
  In this experiment, “ZM1300AN” (hereinafter, chromate treatment) manufactured by Nippon Parkerizing Co., Ltd., which is a commercially available chromate treatment, and “CT-E300” (hereinafter, nonchromate) manufactured by Nippon Parkerizing Co., Ltd., which is a commercially available non-chromate pretreatment. Treatment).
[0119]
  The amount of chromate treatment is 50 mg / m.²The amount of non-chromate treatment is 200 mg / m as the total coating amount.²It was.
[0120]
  Furthermore, on the electrogalvanized steel sheet that had been subjected to pretreatment, the heat-absorbing film coating material described in Table 1 was applied with a roll coater, and then dried and cured in an induction heating furnace that also used hot air. The drying and curing conditions were 230 ° C. at the ultimate plate temperature (PMT). The pretreatment and the heat-absorbing coating material were coated on one side or both sides as necessary to obtain test pieces.
[0121]
  The detail of the produced surface coating board is described in Tables 5-8. In addition, all the surface coating plates described in Tables 5 to 7 are obtained by coating the same type of heat-absorbing coating layer on both sides under the same conditions, and the surface coating plates described in Table 8 are all The heat absorbing film layer is coated only on one side and the other side is not coated.
[0122]
[Table 6]

[0123]
[Table 7]

[0124]
[Table 8]

[0125]
[Table 9]

[0126]
  Hereinafter, the details of the evaluation test of the created surface-coated plate will be described.
[0127]
  1) Emissivity measurement of surface coated plate
  Using a Fourier transform infrared spectrophotometer “VALOR-III” manufactured by JASCO Corporation, wave number of 600 to 3000 cm when the plate temperature of the surface coating plate is 80 ° C.^-1The total emissivity of the surface-coated board was measured by measuring the infrared emission spectrum in the region and comparing this with the emission spectrum of a standard black body. In addition, the standard black body used what spray-coated the THI-1B black body spray with the film thickness of 30 +/- 2 micrometer on the iron plate by Tacos Japan company manufacture (Okitsumo company manufacture).
[0128]
  2) Test for measuring heat absorption of surface-coated plates
  The measurement box shown in FIG. 2 was created and tested. The measurement box 4 has an open top surface, and the open surface is covered with the created surface coating plate 5, and in this state, the temperature controller 7 controls the heat source so that the temperature of the heat source 6 becomes 100 ° C. The temperature A was controlled, and the temperature A of the thermocouple 8 installed in the measurement box 4 and the temperature B of the thermocouple 9 attached to the outer surface of the surface coating plate were measured with the digital thermometer 10, respectively.
[0129]
  In addition, for the untreated electrogalvanized steel sheet with the same thickness as the surface-coated board to be evaluated, the same measurement was performed, and the measured values of the created surface-coated board and the untreated electrogalvanized steel sheet were compared, Evaluation was made according to the following criteria.
[0130]
  The evaluation criteria of the temperature A are as follows.
[{(Measured value of electrogalvanized steel sheet) − (measured value of surface coating plate to be evaluated)} ≧ 4 ° C.]:
[4 ° C.> {(Measured value of electrogalvanized steel sheet) − (measured value of surface coating plate to be evaluated)} ≧ 2 ° C .: Δ
When [2 ° C.> {(Measured value of electrogalvanized steel sheet) − (measured value of surface coated plate to be evaluated)}]: ×
  Moreover, the evaluation criteria of the temperature B are as follows.
When [20 ° C. ≧ {(measured value of surface coating plate to be evaluated) − (measured value of electrogalvanized steel sheet)}]: ○
When [30 ° C. ≧ {(measured value on surface coating plate to be evaluated) − (measured value of electrogalvanized steel sheet)}> 20 ° C.]: Δ
[{(Measured value on surface coating plate to be evaluated) − (measured value of electrogalvanized steel sheet)}> 30 ° C.]: ×
[0131]
  3) Coating film adhesion test
  A 1 mm square grid-like cut was put into the heat-absorbing coating layer of the surface coating plate with a cutter knife and extruded 7 mm with an Erichsen tester so that the coating surface became convex, and then a tape peeling test was conducted.
[0132]
  About the method of making a grid-like cut, the extrusion method of Erichsen, and the method of tape peeling, it implemented according to the method of JIS-K5400.88.2 and the method of JIS-K5400.88.5. In this test, the tape peeling test was carried out twice at the same location (hereinafter referred to as tape peeling twice).
[0133]
  Evaluation after tape peeling was performed according to the figure of the example of evaluation described in JIS-K5400.88.5, evaluated as ◯ when the score was 10 points, Δ when the score was 8 or more and less than 10 points, and × when the score was less than 8 points. .
[0134]
  4) Coating film bending test
  The created surface-coated board was bent 180 °. And the coating-film damage state of the process part was observed with the loupe, and the following references | standards evaluated. The bending process was performed in an atmosphere of 20 ° C. with three 0.6 mm spacers interposed between them (generally called 3T bending).
[0135]
  When there is no damage to the coating film: ○
  If the coating is partially damaged:
  When the paint film is severely damaged on the entire processed part: ×
  5) Press molding test
  The prepared surface coating plate was subjected to a cylindrical drawing test using a hydraulic Erichsen type press working tester. The cylindrical drawing test was performed under the conditions of punch diameter: 50 mm, punch shoulder R: 5 mm, die shoulder R: 5 mm, drawing ratio: 2.3, BHF: 1 t, and processing was performed until the metal plate was drawn from the die. .
[0136]
  Furthermore, the coating film damage state of the processed part was observed with a loupe and evaluated according to the following criteria.
  When there is no damage to the coating film: ○
  If the coating is partially damaged:
  When the paint film is severely damaged on the entire processed part: ×
[0137]
  6) Corrosion resistance
  The salt spray test was implemented with respect to the produced surface coating board by the method of JIS-K5400.99.1. The salt water was sprayed on the surface of the heat absorbing film layer. The test time was 120 hours.
[0138]
  A cross cut was put on the surface of the test piece with a cutter knife. The evaluation method of the coating film in the crosscut portion was evaluated as “◯” when the maximum swollen width on one side of the crosscut was less than 2 mm, “Δ” when it was 2 mm or more and less than 5 mm, and “x” when it was 5 mm or more.
[0139]
  In addition, the above-mentioned salt spray test was performed on the flat plate prepared so that the return (burr) at the time of cutting was on the evaluation surface side of the coated steel sheet (so that it would be an upper burr), and the coating film swelled from the end surface. The width was observed. The evaluation method of the end face part was evaluated as ◯ when the swollen width from the end face was less than 2 mm, Δ when it was 2 mm or more and less than 5 mm, and x when it was 5 mm or more.
[0140]
  7) Conductivity test
  The conductivity of the heat-absorbing film layer of the prepared surface coating plate was measured. The measuring method measured the resistivity of the surface coating board surface by the four-terminal method of the resistivity meter "Loresta-EP / MCP-T360" by Mitsui Chemicals, and evaluated it on the following references | standards.
[0141]
  Resistivity is 0.1 × 10^-2Less than Ω: ○
  Resistivity is 0.1 × 10^-21.0 × 10 or more^-1If less than Ω:
  Resistivity is 1.0 × 10^-1When Ω or more: ×
  Hereafter, the evaluation result of the produced surface coating board is described.
  Table 5 shows the results of evaluating the effect of the additive pigment type and the addition amount of the heat-absorbing film layer coated on the surface-coated plate.
[0142]
  Surface coated plate of the present invention (Invention Example I-1 toI-10, I-12 to I-13, I-17 toI-25) is a wave number of 600 to 3000 cm measured at a temperature of 80 ° C.^-1When the total emissivity in the region is 0.70 or more, the heat absorptivity is higher than Comparative Examples I-26 and I-27 in which the emissivity is less than 0.70, and is suitable as a cover for a heating element. I understand.
[0143]
  When the heat-absorbing coating layer of the surface-coated plate of the present invention is composed of 100 parts by mass of binder solid content, 10 to 150 parts by mass of heat-absorbing pigment, and 1 to 150 parts by mass of conductive pigment, workability In addition, it is excellent in conductivity and is more suitable.
[0144]
  If the amount of the heat-absorbing pigment added is less than 10 parts by mass (Comparative Example I-26), the emissivity is less than 0.7 and the heat-absorbing property is inferior. If the amount of the heat-absorbing pigment added is more than 150 parts by mass (Invention Example I-5), the emissivity is high, but workability such as bendability and press formability is lowered, so 150 parts by mass or less is more preferable. Is preferred.
[0145]
  When the amount of the conductive pigment added is less than 1 part by mass (Invention Example I-8), the conductivity cannot be ensured, so 1 part by mass or more is more preferable. When the addition amount of the conductive pigment is more than 150 parts by mass (Comparative Example I-27), the conductive pigment inhibits the heat absorption, so that the emissivity is less than 0.7 and the heat absorption is inferior, and Since the processability of the coating layer is greatly reduced, it is not suitable.
[0146]
  The heat-absorbing pigment contained in the heat-absorbing film layer of the surface-coated plate of the present invention is carbon black having an average particle diameter of 1 to 100 nm, and the conductive pigment is flaky with an average particle diameter of 0.5 to 50 μm. It is composed of metal Ni and chain metal Ni, and a mass ratio of flake metal Ni / chain metal Ni of 0.1 to 6 is more preferable because it is more excellent in heat absorption and conductivity. .
[0147]
  The heat absorbing pigment is more preferably carbon black having an average particle diameter of 1 to 100 nm.
  A material composed of flaky metal Ni having an average particle size of 0.5 to 50 μm and chain metal Ni is preferable because it hardly inhibits heat absorption. However, the mass ratio of flaky metal Ni / chain metal Ni is less than 0.1 (referenceIn the case of Example I-11), the electrical conductivity decreases, and the flaky metal Ni / chain metal Ni exceeds 6 by mass ratio (referenceIn Example I-14), the heat absorption is hindered and the emissivity is low, so that the mass ratio of flaky metal Ni / chain metal Ni is preferably 0.1-6.
[0148]
  When the conductive pigment is ferrosilicon (Invention Example I-17), the emissivity is not lowered, and the corrosion resistance of the surface coating plate of the present invention is improved, which is more preferable.The
[0149]
  Further, when conductive carbon black is used as the heat-absorbing pigment, it is more preferable because conductivity is improved. In addition to the heat-absorbing pigment and the conductive pigment, the anti-corrosion pigment added to the heat-absorbing film layer of the surface-coated board of the present invention (Invention Example I-22 to I-25) has improved corrosion resistance. Since it is excellent, it is more suitable.
[0150]
  Table 6 shows the evaluation results of the surface-coated plates with different heat-absorbing film layers. When the film thickness is less than 1 μm (Invention Example I-28), the total emissivity is low, and when it exceeds 50 μm, the workability of the coating layer is lowered, so that the film thickness is more preferably 1 to 50 μm.
[0151]
  Table 7 shows the evaluation results in the case where the pretreatment of the heat-absorbing coating layer is a chromate treatment (Invention Example I-35) and in the case where the pretreatment is not performed (Invention Example I-36). Even if the kind of pretreatment is changed, there is no change in emissivity, heat absorption, and other coating film performance.
[0152]
  However, those subjected to the chromate treatment cause environmental problems of hexavalent chromium contained in the chromate-treated film, and therefore a treatment not containing this (non-chromate treatment) is more preferable.
[0153]
  In addition, when the pretreatment is not performed, the coating film adhesion and the corrosion resistance are lowered, and therefore it is more preferable to perform the pretreatment.
[0154]
  Table 8 shows the heat absorption evaluation results when the heat-absorbing film layer is coated only on one surface and the other surface is unpainted. Those coated with a heat-absorbing film only on one side are inferior in heat-absorbing properties to those coated on both sides.
[0155]
  When only one side is coated, a heat-absorbing film layer (Comparative Example I-38) on the outside of the cover covered by the heating element serving as a heat source is not suitable because it has little effect on heat absorption.
[0156]
  Example II
  Hereafter, the detail is demonstrated about the preparation method of the heat absorptive surface coating board used for experiment.
  Adhesion amount is 20g / m per side² 10 mm in an aqueous solution at a temperature of 60 ° C. obtained by diluting “FC-364S” manufactured by Nippon Parkerizing Co., Ltd., which is a commercially available alkaline degreasing agent, to a concentration of 20% by mass. It was degreased by dipping for 2 seconds, washed with water and dried.
[0157]
  Subsequently, the chemical conversion treatment liquid was applied onto the degreased electrogalvanized steel sheet with a roll coater, and was hot-air dried under conditions such that the ultimate plate temperature was 60 ° C.
[0158]
  In this experiment, “ZM1300AN” (hereinafter referred to as chromate treatment) manufactured by Nippon Parkerizing Co., Ltd., which is a commercially available chromate treatment, and “CT-E300” (hereinafter referred to as non-chromate manufactured by Nippon Parkerizing Co., Ltd.), which is a commercially available non-chromate chemical conversion treatment. Treatment). In the chemical conversion treatment, both surfaces of the metal plate were treated with a roll coater and dried under the condition that the ultimate plate temperature was 60 ° C. The amount of chromate treatment is 50 mg / m.²The amount of non-chromate treatment is 200 mg / m as the total coating amount.²It was.
[0159]
  Furthermore, one end (hereinafter referred to as “a-plane”) on the electrogalvanized steel sheet that has been subjected to chemical conversion treatment is coated with the endothermic film paint listed in Table 2 using a roll coater, and induction heating using hot air in combination. Dry and harden in an oven. The drying and curing conditions were 230 ° C. at the ultimate plate temperature (PMT). The chemical conversion treatment and the endothermic film paint were coated on one side or both sides as necessary to obtain test pieces. The other surface (hereinafter referred to as “b surface”) was prepared as unpainted, coated with a heat-absorbing paint, or colored. In addition, for the colored coating, an undercoat “FL641 primer” for pre-coated steel sheets manufactured by Nippon Paint Co., Ltd. is applied with a dry film thickness of 5 μm, baked at PMT 210 ° C., and then overcoated with a black metallic color manufactured by Nippon Paint Co., Ltd. Paint “FL7100” with a dry film thickness of 15 μm and bake at PMT 230 ° C.
[0160]
I attached.
  The details of the prepared surface coating plate are shown in Tables 9-10. In addition, the film thickness of the heat absorbing coating film in Tables 9 to 10 is the film thickness after drying.
[0161]
[Table 10]

[0162]
[Table 11]

  Hereinafter, the details of the evaluation test of the created surface-coated plate will be described.
  1) Emissivity measurement of surface coated plate
  Although it is the same as in Example I, in this experiment, the emissivity of the a-plane of the surface-coated plate produced was measured.
[0163]
  2) Test for measuring heat absorption of surface-coated plates
  As in Example I, but evaluated according to the following criteria. Hereinafter, the evaluation criteria of the temperature A will be described. Moreover, in this experiment, it installed so that the a surface of the surface coating board produced might become the inner side (heat source side) of a measurement box.
[{(Measured value of electrogalvanized steel sheet) − (Measured value of surface coated plate to be evaluated)} ≧ 4 ° C.]:
When [4 ° C.> {(Measured value of electrogalvanized steel sheet) − (measured value of surface coating plate to be evaluated)} ≧ 3 ° C .: ○
[3 ° C.> {(Measured value of electrogalvanized steel sheet) − (measured value of surface coating plate to be evaluated)} ≧ 2 ° C .: Δ
When [2 ° C.> {(Measured value of electrogalvanized steel sheet) − (measured value of surface coated plate to be evaluated)}]: ×
  Hereinafter, the evaluation criteria of the temperature B will be described.
When [20 ° C. ≧ {(measured value of surface coating plate to be evaluated) − (measured value of electrogalvanized steel sheet)}]: ○
When [{(measured value on surface coating plate to be evaluated) − (measured value of electrogalvanized steel sheet)}> 20 ° C.]: Δ
[0164]
  3) Coating film adhesion test
  Same as in Example I. However, in this test, the adhesion of the a surface was evaluated.
[0165]
  4) Coating film bending test
  Same as in Example I. However, this test was carried out so that the a-plane side was the outer side of the processed part, and the coating film damage state of the processed part of the a-plane was observed and evaluated.
[0166]
  5) Press molding test
  Same as in Example I. However, this test was carried out so that the a-plane side was the outer side of the processed part, and the coating film damage state of the processed part of the a-plane was observed and evaluated.
[0167]
  6) Corrosion resistance
  The prepared surface coating plate was subjected to a salt spray test by the method described in JIS-K5400.99.1. The salt water was sprayed on the a side of the test piece. The test time was 72 hours. And, observe the white rust occurrence state of the flat part and the end face part on the a side, ◎ when the white rust has not occurred in both the flat part and the end face part, some white rust has occurred in the end face part If there is almost no white rust on the flat part, ○, white rust is generated on the end face part, and white rust is also partially generated on the flat part. When white rust was generated on the entire surface of the part, it was evaluated as x.
[0168]
  7) Conductivity test
  Same as in Example I. However, this test was conducted on the a-plane.
[0169]
  8) Observation of endothermic paint over time
  The state of the coating liquid after leaving the endothermic paint coated on the surface a of the metal plate at room temperature for 1 month was visually observed and evaluated as follows.
[0170]
  No change compared to the state when the coating liquid was created: ○
  Viscosity is increased compared to the state when the coating solution was prepared:
  Compared to the state when the coating solution was created, the coating solution is in the form of a gel or hardened: ×
[0171]
  9) Appearance of endothermic film
  The appearance of the film coated on the a-plane side on the metal plate was visually observed and evaluated as follows.
  Smooth appearance: ○
  Since the additive pigment is slightly larger than the film thickness, a slight uneven appearance is observed on the surface of the film: Δ
[0172]
  Since the additive pigment is much larger than the film, a severe uneven appearance is observed on the film surface: ×
  Details of the evaluation results are described below.
  The surface-coated plate of the present invention comprises 1 to 20 parts by mass of carbon having a particle size of less than 0.1 μm and 1 to 140 parts by mass of carbon having a particle size of 0.1 to 50 μm with respect to 100 parts by mass of the binder solid content, In addition, heat absorption is achieved by coating a heat-absorbing film layer having a total of 10 to 150 parts by mass of carbon having a particle size of less than 0.1 μm and carbon having a particle size of 0.1 to 50 μm in a dry film thickness of 1 μm or more. A highly functional surface-treated powder metal plate could be obtained.
[0173]
  When using the surface coating board of this invention and producing a heat generating body cover, you have to make a heat | fever absorptive film | membrane inside a heat generating body cover. When the endothermic film of the present invention is coated only on the outer side of the heating element cover (Comparative Example II-32), the temperature inside the cover (endothermic temperature A) is hardly lowered, which is not suitable.
[0174]
  The heat-absorbing film layer of the surface-coated board of the present invention, wave number 600-3000 cm measured at a temperature of 80 ° C.^-1In the case where the total emissivity in the region is less than 0.70 (Invention Example II-26), the temperature inside the cover (endothermic: temperature A) hardly decreases, so the total emissivity is 0.70 or more. Those are more preferred.
[0175]
  When a conductive pigment is added to the heat-absorbing coating layer of the present invention (Invention Example II-11), since conductivity is imparted, it is more suitable for applications where grounding properties are required for the heating element cover. is there. When a rust preventive pigment is added to the heat-absorbing coating layer of the present invention (Invention Examples II-13 and II-14), the corrosion resistance is improved, so that it is more suitable for applications where corrosion resistance is required. Further, when ferrosilicon having both corrosion resistance and conductivity characteristics is added to the heat-absorbing film layer of the present invention (Invention Example II-12), conductivity is imparted and corrosion resistance is also improved. Is preferred. In addition, when the heat-absorbing film is coated only on the inner side of the heating element cover and nothing is coated on the outer side, the temperature inside the cover (the endothermic temperature A) is low and the endothermic material is excellent. Its own temperature (endothermic temperature B) is high. Therefore, it is more preferable that the heat-absorbing film is coated on the inside of the heating element cover, and the heat-absorbing film of the present invention or a generally known colored coating film is further coated on the outside by 10 μm or more.
[0176]
  (Example III)
  Hereafter, the detail is demonstrated about the preparation method of the heat absorptive surface coating board used for experiment.
  Plating adhesion amount is 60g / m per side² 60 ° C. temperature obtained by diluting “FC-364S” manufactured by Nippon Parkerizing Co., Ltd., which is a commercially available alkaline degreasing agent, to a concentration of 20% by mass with a 0.6 mm-thick galvannealed steel sheet (GA) plated on both sides with This was degreased by immersing it in an aqueous solution for 10 seconds, washed with water and dried. Moreover, the amount of plating adhesion is 60 g / m per side.² "FC-315" manufactured by Nihon Parkerizing Co., Ltd., which is a commercially available alkaline degreasing agent for aluminum, using a 0.6 mm thick aluminum plated steel plate (Al sheet) and a 0.6 mm thick aluminum plate (AL) plated on both sides. It was degreased by immersing it in an aqueous solution at a temperature of 70 ° C. diluted to a concentration of 40% by weight for 10 seconds, washed with water and dried.
[0177]
  Next, a chemical conversion treatment liquid was applied on the degreased plated steel sheet and aluminum plate with a roll coater, and dried with hot air under conditions such that the ultimate plate temperature was 60 ° C.
[0178]
  In this experiment, “CT-E300” manufactured by Nippon Parkerizing Co., Ltd., which is a commercially available non-chromate chemical conversion treatment, was used for the chemical conversion treatment. In the chemical conversion treatment, both surfaces of the metal plate were treated with a roll coater and dried under the condition that the ultimate plate temperature was 60 ° C. The amount of chromate treatment is 50 mg / m in terms of Cr adhesion.² The amount of non-chromate treatment is 200 mg / m as the total coating amount.² It was.
[0179]
  Furthermore, paint 1-2 shown in Table 1 of Example I was coated on one side (hereinafter referred to as “a-side”) on the plated steel sheet subjected to chemical conversion treatment, and hot air was used in combination. And dried and cured in an induction furnace. The drying and curing conditions were 230 ° C. at the ultimate plate temperature (PMT). The chemical conversion treatment and the endothermic film paint were coated on one side or both sides as necessary to obtain test pieces. The other surface (hereinafter, this surface is referred to as the b surface) was prepared by coloring. In addition, for the colored coating, an undercoat “FL641 primer” for pre-coated steel sheets manufactured by Nippon Paint Co., Ltd. is applied with a dry film thickness of 5 μm, baked at PMT 210 ° C., and further overcoated with a black metallic color manufactured by Nippon Paint Co., Ltd. The paint “FL7100” was applied at a dry film thickness of 15 μm and baked at PMT 230 ° C.
[0180]
  Table 11 shows the details of the surface-coated plate thus prepared. In addition, the film thickness of the heat-absorbing coating film in Table 11 is the film thickness after drying.
[0181]
[Table 12]

  Hereinafter, the details of the evaluation test of the created surface-coated plate will be described.
  1) Emissivity measurement of surface coated plate
  Same as in Example II
  2) Test for measuring heat absorption of surface-coated plates
  Same as in Example II
  3) Coating film adhesion test
  Same as in Example II
  4) Coating film bending test
  Same as in Example II
  5) Press molding test
  Same as in Example II
  6) Corrosion resistance
  Same as in Example II
  7) Conductivity test
  Same as in Example II
  Details of the evaluation results are described below.
  It is more preferable that the surface-coated plate of the present invention is an iron-zinc alloy plated steel plate such as a molten alloyed galvanized steel plate (Invention Example III-1) because the emissivity is further increased. In addition, a material having high thermal conductivity such as aluminum is used for the original plate (Invention Example III-3), or such a material is plated on a steel material (Invention Example III-2) Alternatively, heat is dissipated on the surface of the metal plate, and the heat on the surface of the metal material plate is made uniform, which is more preferable.
[0182]
  (Example V)
  Hereinafter, a method for producing a heat-absorbing coated plate used in the experiment will be described in detail.
  A heat-absorbing film paint shown in Table 4 was applied onto an alumina ceramic plate with a bar coater and dried at room temperature for about 24 hours. Table 15 shows the details of the created surface-coated board. The surface-coated plates shown in Table 15 are obtained by coating the same type of heat-absorbing coating layer on both surfaces under the same conditions.
[0183]
  Hereinafter, the details of the evaluation test of the prepared surface treatment plate will be described.
  1) Emissivity measurement test of surface coated plate
  Same as in Example IV.
  2) Test for measuring heat absorption of surface-coated plates
  Same as in Example IV.
  3) Impact resistance test of coating film
  Same as in Example IV.
  4) Observation of endothermic paint over time
  Each endothermic coating paint applied to the ceramic plate was evaluated as in Example II.
  5) Appearance of endothermic film
  The appearance of the film coated on the ceramic plate was visually observed and evaluated in the same manner as in Example II.
[0184]
  Hereinafter, the details of the evaluation results of the prepared surface coating plate will be described.
  As shown in Table 15, the surface coating plate of the present invention has 1 to 20 parts by mass of carbon having a particle size of less than 0.1 μm and a particle size of 0.1 to 30 μm with respect to 100 parts by mass of the resin solid content. A heat-absorbing coating layer containing 1 to 140 parts by mass of carbon and having a total of 10 to 150 parts by mass of carbon having a particle size of less than 0.1 μm and carbon having a particle size of 0.1 to 50 μm is dried. By coating with a thickness of 1 μm or more, it was possible to obtain a surface-coated plate with high heat absorption.
[0185]
[Table 13]

[0186]
  Example VI
  Hereinafter, the details of the method for producing the coated plate material used in the experiment will be described.
  On a plate-like polycarbonate-ABS polymer alloy resin (hereinafter referred to as a plastic plate), the paint 3-2 and the paint 3-20 shown in Table 3 were coated with a bar coater and dried at room temperature for about 24 hours. . Table 16 shows the details of the created surface-coated plate. The surface-coated plates shown in Table 16 are obtained by coating the same kind of endothermic coating layers on both surfaces under the same conditions.
[0187]
  Hereinafter, the details of the evaluation test of the created surface-coated plate will be described.
  1) Emissivity measurement test of surface coated plate
  Same as in Example IV.
  2) Test for measuring heat absorption of surface-coated plates
  Same as in Example IV.
  3) Impact resistance test of coating film
  Same as in Example IV.
Table 16 shows the evaluation results of the surface coating plate created. The surface-coated board of the present invention is suitable because it has an effect on heat absorption even when a plastic material such as a resin is used as a base material.
[0188]
[Table 14]

  Example VII
  Hereafter, the detail is demonstrated about the preparation method of the heat absorptive precoat metal plate used for experiment.
  A metal plate having a thickness of 0.6 mm was alkali degreased in an aqueous solution at a temperature of 60 ° C. obtained by diluting “FC4336” manufactured by Nippon Parkerizing Co., Ltd., which is a commercially available alkaline degreasing agent, to a concentration of 2% by mass, washed with water, and dried. Subsequently, the chemical conversion treatment liquid was applied onto the degreased electrogalvanized steel sheet with a roll coater, and was hot-air dried under conditions such that the ultimate plate temperature was 60 ° C.
[0189]
  In this experiment, the following metal plate was used.
GI: Hot-dip galvanized steel sheet (Z12)
GA: Alloyed galvanized steel sheet (F08)
Al sheet: Aluminum-plated steel sheet (Aluminum adhesion amount: 60 g / m2 on one side)
SUS: Stainless steel sheet (SUS430, surface bright finish)
  In addition, in this experiment, “ZM1300AN” (hereinafter referred to as chromate treatment) manufactured by Nippon Parkerizing Co., Ltd., which is a commercially available chromate treatment, and “CT-E300” manufactured by Nippon Parkerizing Co., Ltd., which is a commercially available non-chromate chemical conversion treatment (hereinafter referred to as “Chemical Treatment”). Non-chromate treatment) was used. In the chemical conversion treatment, both surfaces of the metal plate were treated with a roll coater and dried under the condition that the ultimate plate temperature was 60 ° C. The amount of chromate treatment is 50 mg / m.²The amount of non-chromate treatment is 200 mg / m as the total coating amount.²It was.
[0190]
  Furthermore, the paint selected from Tables 1 and 2 previously prepared was applied to one side (hereinafter referred to as “a-side”) on the metal plate subjected to chemical conversion treatment with a roll coater, and hot air was used in combination. Dry and harden in an induction heating furnace. The drying and curing conditions were 230 ° C. at the ultimate plate temperature (PMT). On the other side (hereinafter, this side is referred to as b side), a colored paint or a clear paint was applied with a roll coater. In addition, the colored paint is prepainted steel coating undercoat “FL641 primer” manufactured by Nippon Paint Co., Ltd. with a dry film thickness of 5 μm roll coater, baked at PMT 210 ° C., and further white coated by Nippon Paint Co., Ltd. The top coating “FL3510” was applied with a 15 μm roll coater with a dry film thickness, and baked at PMT 230 ° C. As the clear paint, 3 μm of FL5000 clear manufactured by Nippon Paint Co., Ltd. was applied. In addition, the primer coating “FL641 primer” for the colored coating layer used in this experiment is a chromate in which 48% by mass of strontium chromate is added to the resin solid content when coated on a chromate-treated metal plate. When a non-chromate type metal plate was used and coated on a non-chromated metal plate, a non-chromate type material added with 30% by mass of calcium silicate was used.
[0191]
  Details of the pre-coated metal sheet prepared are shown in Table 17. In addition, the film thickness of the heat-absorbing coating film in Table 17 is the film thickness after drying.
[0192]
  Hereinafter, the details of the method of making the refrigerator used in the experiment will be described.
  The metal outer plate of a commercially available small refrigerator was removed. Next, the refrigerator was created by attaching the pre-coated metal plate cut and processed into the same shape as the removed metal plate so that the a-side of the pre-coated metal plate is inside the refrigerator.
[0193]
  Hereinafter, the details of the evaluation test of the created surface-coated plate will be described.
  1) Emissivity measurement of refrigerator outer plate
  Using a Fourier transform infrared spectrophotometer “VALOR-III” manufactured by JASCO Corporation, a wave number of 600 to 3000 cm when the plate temperature of a pre-coated metal plate prepared for use in a refrigerator outer plate is 80 ° C.^-1The total emissivity of the genus plate was measured by measuring the infrared emission spectrum in this region and comparing it with the emission spectrum of a standard black body. In addition, the standard black body used what spray-coated the THI-1B black body spray with the film thickness of 30 +/- 2 micrometer on the iron plate by Tacos Japan company manufacture (Okitsumo company manufacture).
[0194]
  The emissivity was measured by measuring the a-plane of the prepared precoated metal sheet.
  2) Temperature measurement test inside the refrigerator
  The prepared refrigerator was turned on and operated under normal conditions, and the temperature in the vicinity of the motor, which was the main heat source inside 24 hours after the start of operation, was measured with a digital temperature. The temperature was measured at a location 5 cm away from the motor.
[0195]
  Furthermore, the temperature inside the refrigerator with the conventional metal outer plate (conventional metal outer plate) originally attached to a commercially available refrigerator is measured under the above-described conditions, and the estimated temperature of the refrigerator to be evaluated is determined. In comparison, the evaluation was as follows.
[0196]
  Hereinafter, the evaluation criteria of the temperature inside the refrigerator will be described.
[{(Measured value of refrigerator having conventional metal outer plate) − (Measured value of refrigerator to be evaluated)} ≧ 4 ° C.]
When [4 ° C.> {(Measured value of refrigerator having conventional metal skin) − (measured value of refrigerator to be evaluated)} ≧ 2 ° C.]: Δ
When [2 ° C.> {(Measured value of a refrigerator having a conventional metal outer plate) − (measured value of a refrigerator to be evaluated)}]: ×
[0197]
  3) Film adhesion test of refrigerator outer plate
  Insert a 1 mm square grid-like cut into the coating layer on the a side of the pre-coated metal plate made for the refrigerator outer plate with a cutter knife, and extrude 7 mm with an Erichsen tester so that the a side is convex, then tape A peel test was performed.
  About the method of making a grid-like cut, the extrusion method of Erichsen, and the method of tape peeling, it implemented according to the method of JIS-K5400.88.2 and the method of JIS-K5400.88.5.
  Evaluation after tape peeling was performed according to the figure of the example of evaluation described in JIS-K5400.88.5, evaluated as ◯ when the score was 10 points, Δ when the score was 8 or more and less than 10 points, and × when the score was less than 8 points. .
[0198]
  4) Processability of refrigerator outer plate
  When the prepared pre-coated metal plate was processed into an outer plate of a refrigerator, the damage state of the film on the a-plane side processed portion was visually observed and evaluated as follows.
[0199]
  Good appearance with no cracks or peeling of the film in the processed part: ○
  Small cracks and delamination occur in the coating on the processed part: △
  The film peels almost entirely at the processed part: ×
  5) Corrosion resistance of refrigerator outer plate
  The salt spray test was implemented by the method of JIS-K5400.99.1 about the precoat metal plate produced for refrigerator outer plates. The salt water was sprayed on the a side of the test piece. The test time was 48 hours. Then, observe the white rust occurrence state of the flat part on the a side, ○ if the white rust is not generated from the flat part, ○ if the white rust is generated in the flat part but red rust is not generated (Triangle | delta) and the case where white rust and red rust have generate | occur | produced also in the plane part were evaluated as x.
[0200]
  6) Conductivity test of refrigerator outer plate
  The conductivity of the a-side of the precoated steel plate prepared for the refrigerator outer plate was measured. The measuring method measured the resistivity of the surface of a metal plate by the four terminal method of the resistivity meter "Loresta-EP / MCP-T360" by Mitsui Chemicals, and evaluated it on the following references | standards.
[0201]
  Resistivity is 0.1 × 10^-2Less than Ω: ○
  Resistivity is 0.1 × 10^-21.0 × 10 or more^-1If less than Ω:
  Resistivity is 1.0 × 10^-1When Ω or more: ×
  7) Investigation of viscosity change with time of heat-absorbing coatings
  The heat-absorbing paint used in this experiment (paint selected from Tables 1 and 2) was diluted with an organic solvent (Sorbesso 150 and cyclohexanone mixed at a mass ratio of 1: 1), and the total solid content (N V.) was adjusted to 50 mass%.
[0202]
  And the initial viscosity of the prepared paint is JIS. Ford Cup No. described in K540.4.5.4. Measurement was performed by the four methods. Furthermore, the viscosity of these paints after leaving them at room temperature for 1 week and then re-stirring with a stirrer was again set as the viscosity after 1 week. Measurement was performed by the four methods. And the viscosity increase before and after leaving for one week was compared, and the viscosity increase of each created paint was evaluated as follows. The evaluation results of the viscosity change test are shown in Table 18.
[0203]
[(Viscosity after one week)-(initial viscosity)] <20 seconds: 〇
When 20 ≦ [(viscosity after one week) − (initial viscosity)] <50 seconds: Δ
[(Viscosity after one week) − (initial viscosity)] ≧ 50 seconds: ×
[0204]
[Table 15]

[0205]
[Table 16]

[0206]
  When the heat-absorbing film coated on the refrigerator outer plate of the present invention contains 10 to 150 parts by mass of carbon with respect to 100 parts by mass of the binder solid content, the emissivity of the heat-absorbing film is preferably 0.70 or more. Carbon with an added amount of less than 10 (Comparative Example-VII-15, VII-16, VII-18) and uncoated (Comparative Example VII-19) are not suitable because the emissivity is less than 0.70. is there. Moreover, since the addition amount of carbon exceeds 150 mass parts (comparative example VII-17) is inferior to workability, it is unsuitable.
[0207]
  Since the heat absorbing film of the refrigerator outer plate of the present invention to which a conductive pigment is added is imparted with conductivity, it is difficult for static electricity to occur during refrigerator assembly, and there is no problem of dust or dust adhesion due to static electricity. More preferred. When no conductive pigment is added (referenceExamples VII-6, VII-8, and VII-9) have poor conductivity.
[0208]
  The heat-absorbing film of the refrigerator outer plate of the present invention added with a rust preventive pigment (Invention Example VII-7,Reference exampleVII-8 and VII-9) are excellent in corrosion resistance and more suitable. In particular, a material to which ferrosilicon is added (Invention Example VII-7) is more suitable because it is excellent in conductivity in addition to corrosion resistance.
[0210]
  If the chemical conversion treatment is performed on the refrigerator outer plate of the present invention before the heat-absorbing film is applied, it is excellent in adhesion and workability, and is more preferable. Those not subjected to chemical conversion treatment (Example VII-12 of the present invention) are inferior in adhesion and workability. Further, any type of chemical conversion treatment may be used, but the one subjected to non-chromate treatment is more suitable than the one using chromate treatment (Invention Example VII-11) from the viewpoint of environmental problems.
[0211]
  Example VIII
  Hereinafter, a method for producing a heat-absorbing coated plate used in the experiment will be described in detail.
  The heat-absorbing film paint shown in Table 4 was applied to the inner surfaces of the aluminum alloy plate and the magnesium alloy plate with a bar coater and dried at room temperature for about 24 hours. Table 19 (Al alloy plate) and Table 20 (Mg alloy plate) show the details of the prepared surface-coated plates. The surface-coated plates shown in Table 19 and Table 20 are obtained by coating the same type of heat-absorbing coating layer on both sides under the same conditions.
[0212]
  Hereinafter, the details of the evaluation test of the prepared surface treatment plate will be described.
  1) Emissivity measurement of surface coating board material
  Same as in Example IV
  2) Test for measuring heat absorption of surface-coated board materials
  Same as in Example IV
  3) Impact resistance test of coating film
  Same as in Example IV
  4) Observation of endothermic paint over time
  Each endothermic coating material coated on the aluminum alloy plate and the magnesium alloy plate was evaluated in the same manner as in Example II.
[0213]
  5) Appearance of endothermic film
  The appearance of the film coated on the aluminum alloy plate and the magnesium alloy plate was visually observed and evaluated in the same manner as in Example II.
[0214]
  Hereinafter, the details of the evaluation results of the prepared surface coating plate will be described.
  As shown in Table 19 and Table 20, the surface coating plate of the present invention has 1 to 20 parts by mass of carbon having a particle size of less than 0.1 μm and a particle size of 0.1 μm or more with respect to 100 parts by mass of the resin solid content. A heat-absorbing coating layer containing 1 to 140 parts by mass of carbon of 50 μm or less, and the total of carbon having a particle size of less than 0.1 μm and carbon having a particle size of 0.1 μm or more and 50 μm or less is 10 to 150 parts by mass. By coating the film with a dry film thickness of 1 μm or more, it was possible to obtain a highly heat-absorbing surface coating plate.
[0215]
[Table 17]

[0216]
[Table 18]

  Example IX
  Hereinafter, the details of the method for producing the coated plate material used in the experiment will be described.
  On a plate-like polycarbonate-ABS polymer alloy resin (hereinafter referred to as a plastic plate), the paint 4-2 and paint 4-9 shown in Table 4 were applied with a bar coater and dried at room temperature for about 24 hours. . Table 21 shows the details of the created surface-coated board. The surface-coated plates shown in Table 21 are obtained by coating the same type of endothermic success / failure film layers on both surfaces under the same conditions.
[0217]
  Hereinafter, the details of the evaluation test of the created surface-coated plate will be described.
  1) Emissivity measurement test of surface coated plate
  Same as in Example IV.
  2) Test for measuring heat absorption of surface-coated plates
  Same as in Example IV.
  3) Impact resistance test of coating film
  Same as in Example IV.
  Table 21 shows the evaluation results of the surface coating plate created. The surface-coated board of the present invention is suitable because it has an effect on heat absorption even when a plastic material such as a resin is used as a base material.
[0218]
[Table 19]

  (Example X)
  Hereinafter, the method for producing the heat-absorbing aluminum alloy plate used in the experiment will be described in detail.
  A 0.6 mm aluminum alloy plate was degreased by immersing it in an aqueous solution at a temperature of 60 ° C. diluted with 20% by weight of “FC-315” manufactured by Nippon Parkerizing Co., Ltd., which is a commercially available alkaline degreasing agent, After washing with water, it was dried. Furthermore, “CTE-300” manufactured by Nihon Parkerizing Co., Ltd., which is a commercially available non-chromate treatment, is applied to a dry adhesion amount of 200 mg / m²Painted with a roll coater.
[0219]
  Next, a heat-absorbing film paint described in Table 1 was applied on the degreased aluminum alloy plate with a roll coater, and dried and hardened in an induction heating furnace combined with hot air. The drying and curing conditions were 230 ° C. at the ultimate plate temperature (PMT). The heat-absorbing film paint was applied to one side or both sides as required to obtain a test piece.
[0220]
  Details of the prepared surface-treated aluminum alloy plate are shown in Table 22. All of the aluminum alloy plates described in Table 22 are coated with a heat-absorbing coating layer only on one surface and not coated on the other surface.
[0221]
[Table 20]

[0222]
Hereinafter, the details of the evaluation test of the prepared aluminum alloy plate will be described.
  1) Emissivity measurement of aluminum alloy plate
  Same as Example I.
  2) Test for measuring heat absorption of aluminum alloy sheets
  Same as Example IV.
  3) Coating film adhesion test
  Same as Example I.
  4) Coating film bending test
  Same as Example I.
  5) Press molding test
  Same as Example I.
  6) Corrosion resistance
  The salt spray test was implemented with the method of JIS-K5400.99.1 with respect to the produced aluminum alloy plate. The salt water was sprayed on the surface of the heat absorbing film layer. The test time was 500 hours.
[0223]
  The evaluation method of the coating film in the crosscut portion was evaluated as “◯” when the maximum swollen width on one side of the crosscut was less than 2 mm, “Δ” when it was 2 mm or more and less than 5 mm, and “x” when it was 5 mm or more.
[0224]
  In addition, the above-mentioned salt spray test was performed on the flat plate prepared so that the return (burr) at the time of cutting was on the evaluation surface side of the coated steel sheet (so that it would be an upper burr), and the coating film swelled from the end surface. The width was observed. The evaluation method of the end face part was evaluated as ◯ when the swollen width from the end face was less than 2 mm, Δ when it was 2 mm or more and less than 5 mm, and x when it was 5 mm or more.
[0225]
  7) Conductivity test
  Same as Example I.
  Table 22 shows the results of evaluating the effect of the additive pigment type and the addition amount of the heat-absorbing film layer coated on the aluminum alloy plate.
[0226]
  Aluminum alloy plate of the present invention (Invention Example X-1X-10, X-12, X-13, X-17 ~X-25) is a wave number of 600 to 3000 cm measured at a temperature of 80 ° C.^-1When the total emissivity in the region is 0.70 or more, the heat absorptivity is higher than those of Comparative Examples X-26 and X-27 where the emissivity is less than 0.70, and is suitable as a case of a heating element. I understand.
[0227]
  When the heat-absorbing coating layer of the aluminum alloy plate of the present invention is composed of 100 parts by mass of binder solid content, 10 to 150 parts by mass of heat-absorbing pigment, and 1 to 150 parts by mass of conductive pigment, workability In addition, it is excellent in conductivity and is more suitable.
[0228]
  If the amount of the heat-absorbing pigment added is less than 10 parts by mass (Comparative Example X-26), the emissivity is less than 0.7 and the heat-absorbing property is inferior. If the added amount of the heat-absorbing pigment is more than 150 parts by mass (Example X-5 of the present invention), the emissivity is high, but the workability such as bendability and press formability is lowered, so 150 parts by mass or less is more. Is preferred.
[0229]
  When the amount of the conductive pigment added is less than 1 part by mass (Example X-8 of the present invention), the conductivity cannot be ensured, so 1 part by mass or more is more preferable. When the addition amount of the conductive pigment exceeds 150 parts by mass (Comparative Example X-27), the conductive pigment inhibits heat absorption, so that the emissivity is less than 0.7 and the heat absorption is inferior, and Since the processability of the coating layer is greatly reduced, it is not suitable.
[0230]
  The heat-absorbing pigment contained in the heat-absorbing film layer of the aluminum alloy plate of the present invention is carbon black having an average particle diameter of 1 to 100 nm, and the conductive pigment is flaky with an average particle diameter of 0.5 to 50 μm. It is composed of metal Ni and chain metal Ni, and a mass ratio of flake metal Ni / chain metal Ni of 0.1 to 6 is more preferable because it is more excellent in heat absorption and conductivity. .
[0231]
  When the heat-absorbing pigment has a relatively large particle size such as charcoal powder or graphite powder (the present invention X-6 and X-7), the emissivity is relatively low and the conductive pigment has a large conductive effect. Since the heat-absorbing pigment is inhibited and the conductivity is lowered, the heat-absorbing pigment is more preferably carbon black having an average particle diameter of 1 to 100 nm.
[0232]
  When the conductive pigment contained in the heat-absorbing film layer of the aluminum alloy plate of the present invention is aluminum powder or stainless steel powder, these conductive pigments are likely to inhibit heat absorption, and these are added (referenceExamples X-15 and X-16) have a reduced emissivity.
[0233]
  A material composed of flaky metal Ni having an average particle size of 0.5 to 50 μm and chain metal Ni is preferable because it hardly inhibits heat absorption. However, the mass ratio of flaky metal Ni / chain metal Ni is less than 0.1 (referenceIn the case of Example X-11), the conductivity decreases, and the flake metal Ni / chain metal Ni exceeds 6 by mass ratio (referenceIn Example X-14), the heat absorption is inhibited and the emissivity is low, so that the mass ratio of flaky metal Ni / chain metal Ni is preferably 0.1-6.
[0234]
  When the conductive pigment is ferrosilicon (Example X-17 of the present invention), the emissivity is not lowered, and the corrosion resistance of the aluminum alloy plate of the present invention is also improved. A material in which only ferrosilicon is added without adding a heat-absorbing pigment (Example X-19 of the present invention) is preferable because it has a relatively high emissivity and is excellent in conductivity and corrosion resistance.
[0235]
  Further, when conductive carbon black is used as the heat-absorbing pigment, it is more preferable because conductivity is improved. In addition to the heat-absorbing pigment and the conductive pigment in the heat-absorbing coating layer of the aluminum alloy plate of the present invention, a rust-preventive pigment is added (invention example X-22 to X-25) to improve corrosion resistance. Since it is excellent, it is more suitable.
[0236]
  Table 7 shows the evaluation results of aluminum alloy plates having different heat absorbing coating layer thicknesses. When the film thickness is less than 1 μm (Invention Example X-28), the total emissivity is low, and when it exceeds 50 μm, the workability of the coating layer is lowered, so that the film thickness is more preferably 1 to 50 μm.
[0237]
[Brief description of the drawings]
FIG. 1 is a diagram showing a configuration of a heating element cover or case excellent in heat absorption according to the present invention.
FIG. 2 is a diagram showing an embodiment of a measurement box for measuring heat absorption.

Claims (24)

At least the inner surface of the heating element cover body is coated with a heat-absorbing coating layer having a total emissivity of 0.70 or more in a region of wave number 600 to 3000 cm ⁻¹ measured at a temperature of 80 ° C. or more and 200 ° C. or less, The heat-absorbing coating layer has a binder solid content of 100 parts by mass and, as a heat-absorbing pigment, 1 to 20 parts by mass of carbon having a particle size of less than 0.1 μm and 1 to 1 to carbon having a particle size of 0.1 to 50 μm. A heating element cover excellent in heat absorption, comprising 140 parts by mass and the total of carbon having a particle size of less than 0.1 μm and carbon having a particle size of 0.1 μm or more and 50 μm or less being 10 to 150 parts by mass . 2. The heat absorption according to claim 1, wherein the heat-absorbing coating layer further comprises 1 to 150 parts by mass of a conductive pigment, together with 100 parts by mass of the binder solid content and 10 to 150 parts by mass of the heat-absorbing pigment. Excellent heating element cover. Before Kishirube conductive pigment is composed of a flaky metallic Ni and chain metal Ni with an average particle diameter of 0.5 to 50 [mu] m, and, 0.1 mass ratio of the flake-like metallic Ni / metal chain Ni The heating element cover excellent in heat absorption according to claim 2, wherein the heating element cover is 6.   The heating element cover excellent in heat absorption according to any one of claims 2 to 3, wherein the conductive pigment is ferrosilicon.   The heating element cover according to any one of claims 1 to 4, wherein the heating element cover body is made of metal.   The heating element cover according to any one of claims 1 to 4, wherein the heating element cover body is made of non-metal. At least one surface of a metal plate or a plated metal plate is covered with a heat-absorbing coating layer having a total emissivity of 0.70 or more in a region of wave number 600 to 3000 cm ⁻¹ measured at a temperature of 80 ° C. or more and 200 ° C. or less. The heat-absorbing coating layer has a binder solid content of 100 parts by mass and, as a heat-absorbing pigment, 1 to 20 parts by mass of carbon having a particle size of less than 0.1 μm and carbon having a particle size of 0.1 to 50 μm. 1 to 140 parts by mass, and the total of carbon having a particle size of less than 0.1 μm and carbon having a particle size of 0.1 μm or more and 50 μm or less is 10 to 150 parts by mass, and has excellent heat absorption Surface treatment metal plate. The heat absorption film according to claim 7, wherein the heat absorption film layer further comprises 1 to 150 parts by mass of a conductive pigment together with 100 parts by mass of binder solid content and 10 to 150 parts by mass of heat absorption pigment. Excellent surface treatment metal plate. Before Kishirube conductive pigment is composed of a flaky metallic Ni and chain metal Ni with an average particle diameter of 0.5 to 50 [mu] m, and, 0.1 mass ratio of the flake-like metallic Ni / metal chain Ni The surface-treated metal plate having excellent heat absorption according to claim 8, wherein   The surface-treated metal plate excellent in heat absorption according to any one of claims 8 to 9, wherein the conductive pigment is ferrosilicon. The surface-treated metal plate excellent in heat absorbability according to any one of claims 7 to 10, wherein the heat-absorbent film has a thickness of 1 to 50 µm. A heat-absorbing film having a total emissivity of 0.70 or more in a region of wave number 600 to 3000 cm ⁻¹ measured at a temperature of 80 ° C. or more and 200 ° C. or less is coated on the inner surface of the outer plate, and the heat-absorbing film However, with respect to 100 parts by mass of binder solid content, 1 to 20 parts by mass of carbon having a particle size of less than 0.1 μm and 1 to 140 parts by mass of carbon having a particle size of 0.1 to 50 μm are included as a heat absorbing pigment , The total of carbon having a particle size of less than 0.1 μm and carbon having a particle size of 0.1 μm or more and less than 50 μm is 10 to 150 parts by mass, and contains 1 to 50 parts by mass of a metal powder as a conductive pigment , and is dried. A refrigerator excellent in thermal efficiency, characterized by having a film thickness of 1 μm or more. The refrigerator with excellent thermal efficiency according to claim 12 , wherein the outer plate is coated with a clear coating or a coating containing a color pigment. It has a heat-absorbing film layer inside the case of a portable device or an in-vehicle device that contains an electronic component that generates heat, and the heat-absorbing film layer is
(A) 1 to 20 parts by mass of carbon having a particle size of less than 0.1 μm and 1 to 140 parts by mass of carbon having a particle size of 0.1 to 50 μm as a heat-absorbing pigment with respect to 100 parts by mass of binder solid content The total of carbon having a particle size of less than 0.1 μm and carbon having a particle size of 0.1 μm or more and 50 μm or less is 10 to 150 parts by mass;
(B) Carbon black having a binder solid content of 100 parts by weight, a heat absorbing pigment of 10 to 150 parts by weight, and a conductive pigment of 1 to 150 parts by weight, wherein the heat absorbing pigment has an average particle diameter of 1 to 100 nm The conductive pigment is composed of flaky metal Ni having an average particle size of 0.5 to 50 μm and chain metal Ni, and the mass ratio of flaky metal Ni / chain metal Ni is 0.1 to 6;
(C) 100 mass parts of binder solid content, 10-150 mass parts of heat absorbing pigment, and 5-150 mass parts of ferrosilicon (D) 100 mass parts of binder solid content and 5-150 ferrosilicon A portable device or an in-vehicle device, characterized in that it is any one of mass parts.   A portable device or a vehicle-mounted device, wherein the case of the portable device or the vehicle-mounted device containing an electronic component that generates heat is the heating element cover according to any one of claims 1 to 6. A case of a portable device or an in-vehicle device containing an electronic component that generates heat is obtained by processing the surface-treated metal plate according to any one of claims 7 to 11 , and the heat absorption property of the metal plate A portable device or an in-vehicle device, wherein the coating layer is an inner surface.   The portable device or in-vehicle device according to any one of claims 14 to 16, wherein the case is made of Mg alloy or Al alloy. The case for portable apparatuses or vehicle equipment which has the heat | fever absorptive film layer of Claim 14 . A heat-absorbing coating layer having a total emissivity of 0.70 or more in a region of wave number 600 to 3000 cm ⁻¹ previously measured at a temperature of 80 ° C. or more and 200 ° C. or less on at least one surface of a metal plate or a plated metal plate. Is a pre-coated surface-treated metal plate that is then molded and processed , wherein the heat-absorbing coating layer has a binder solid content of 100 parts by mass, and a carbon black of 10 to 100 nm in average particle diameter as a heat-absorbing pigment 150 parts by mass and further composed of 1 to 150 parts by mass of metal Ni as a conductive pigment , and the metal Ni is composed of flaky metal Ni having an average particle size of 0.5 to 50 μm and chain metal Ni It is, and, flaked metals Ni / mass ratio of the chain metal Ni is characterized 0.1-6 der Rukoto, heat absorbing excellent precoated surface treated metal sheet. The precoated surface-treated metal sheet with excellent heat absorption according to claim 19 , wherein the carbon black in the heat absorption film layer is 10 to 15 parts by mass. The mass ratio of said flaky metal Ni / chain metal Ni is 6, The precoat surface-treated metal plate excellent in heat absorption of Claim 20 characterized by the above-mentioned. At least one surface of a metal plate or a plated metal plate is coated with a heat-absorbing coating layer having a total emissivity of 0.70 or more in a region of wave number 600 to 3000 cm ⁻¹ measured at a temperature of 80 ° C. or more and 200 ° C. or less. In addition, the heat-absorbing coating layer has a binder solid content of 100 parts by mass, a carbon black of 10 to 150 parts by mass with an average particle diameter of 1 to 100 nm as a heat-absorbing pigment, and a ferrosilicon 1 to 1 as a conductive pigment. A precoated surface-treated metal plate having excellent heat absorbability, comprising 150 parts by mass. 23. The precoated surface-treated metal sheet excellent in heat absorption according to any one of claims 19 to 22 , wherein the heat absorption film has a thickness of 1 to 50 [mu] m.   24. A heat absorption, wherein the precoated surface-treated metal sheet according to claim 19 is formed and processed so that the surface having the heat-absorbing film is at least the inner surface of the cover. Excellent heating element cover.

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