JP2004178776A - Magnetoresistance effect type magnetic head, and recording and reproducing device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent corrosion from occurring on the medium sliding and touching surface of a magnetoresistance effect type magnetic head making a slidable contact with a magnetic recording medium. <P>SOLUTION: A rust inhibitor film 50 including a carboxylic acid amine salt compound is formed on the medium sliding and touching surface 20a of a GMR head 20 for detecting a magnetic signal while making a slidable contact with a magnetic tape 3. Also, a top coat layer 64 and a back coat layer 65 formed from the same material as the rust inhibitor film 50 formed on the medium sliding and touching surface 20a of the GMR head 20 are formed on the surface of the magnetic tape 3, and the rust inhibitor film is copied on the medium sliding and touching surface 20a of the GMR head 20 which is brought into a slidable contact with the magnetic tape 30. <P>COPYRIGHT: (C)2004,JPO

Description

【００７１】
但し、上記〔化１〕中、Ｒ_１、Ｒ_２、Ｒ_３は、水素あるいは飽和、不飽和の脂肪酸炭化水素基を示す。
【００７２】
上記カルボン酸アミン塩化合物は、パーフルオルポリエーテル鎖（ＰＦＰＥ）、あるいはフロロアルキル鎖を有するものであることが好ましい。パーフルオルポリエーテル鎖（ＰＦＰＥ）、あるいはフロロアルキル鎖中のフッ素により撥水性をもたせ、水分の吸着を抑制し、耐食性を向上することができる。
また、フッ素は磁気テープ走行時における耐久性を向上させる作用がある。
さらには、アミン化合物ならびにカルボン酸化合物は摩擦低下に効果があり、磁気テープ走行時の摩擦を低下させ、磁気テープおよび磁気ヘッドの摩擦力が緩和され、走行耐久性が向上する。
【００７３】
ここで、パーフルオロポリエーテルおよびフロロアルキルは、市販のものをいずれも適用可能であるが、好ましくは、カルボン酸アミン塩化合物が、下記〔化２〕、〔化３〕で示される化合物であり、上記パーフルオルポリエーテル鎖あるいはフロロアルキル鎖の平均分子量が３００〜８０００であればよい。パーフルオロポリエーテルおよびフロロアルキルの平均分子量が３００未満になると磁気テープの摩擦が高くなり、磁気テープ走行時のドラムへの貼り付きの原因となる。一方、平均分子量が８０００よりも大きくなると、有機溶媒に対して溶けにくくなり、さらには凝集するため磁気テープへ塗布する時に塗布ムラが起こりやすく、均一に塗布できなくなる。
カルボン酸アミン塩化合物を塗布する際には、既存の炭化水素系溶媒に溶解して塗布すればよい。また塗布方法についても公知の方法がいずれも適用できる。
【００７４】
【化２】

【００７５】
【化３】

【００７６】
但し、上記〔化２〕、〔化３〕中、Ｒｆはパーフルオロポリエーテル鎖、あるいはフロロアルキル鎖であり、Ｒ_１、Ｒ_２、Ｒ_３は、水素あるいは飽和、不飽和の脂肪酸炭化水素基を示す。
【００７７】
カルボン酸アミン塩化合物は、上述したスピンバルブ膜４０の磁気抵抗変化率（ＭＲ比）に影響を与える非磁性層４４のＣｕやＣｕＡｕとの反応性が良く、海水雰囲気下での塩素イオンに対する耐食性に優れているという特長を有している。
【００７８】
また、防錆剤膜５０の膜厚は、１〜５００Åの範囲とすることが好ましい。
防錆剤膜５０の膜厚が１Åよりも薄くなると、耐食性を維持することが困難となり、一方、この防錆剤膜５０の膜厚が５００Åよりも厚くなると、ＧＭＲヘッド２０と磁気テープ３との間のスペーシングとなり、このＧＭＲヘッド２０の出力感度が低下してしまうためである。従って、この防錆剤膜５０の膜厚を１〜５００Åの範囲に規定することで、優れた耐食性を示し、かつ高い磁気抵抗変化率を維持することができる。また、防錆剤膜５０の膜厚は、２〜２００Åの範囲であることがより好ましく、さらに、この防錆剤膜５０の膜厚を５〜１００Åの範囲に規定すれば、ＧＭＲ素子２７の腐食等の発生を防止すると共に、このＧＭＲ素子２７の良好な短波長記録再生特性を得ること可能である。
【００７９】
なお、具体的に、上述したスピンバルブ膜４０を構成する非磁性層４４のＣｕＡｕとの反応性が良く、海水雰囲気下での塩素イオンに対する耐食性に優れた防錆剤膜５０として、下記〔化４〕に示すカルボン酸アミン塩化合物を塗布することにより形成したところ、上述したような優れた効果が確認された。
【００８０】
【化４】

【００８１】
但し、上記〔化４〕は、上記〔化２〕においてＲｆを（ＣＦ_２ＣＦ_２Ｏ）_ｍ（ＣＦ_２Ｏ）_ｎ（分子量＝４０００）とした。
【００８２】
上述したように、本発明に係るＧＭＲヘッド２０においては、磁気テープ３と摺接される媒体摺接面２０ａに、例えばＤＬＣ膜等の保護膜を形成しない場合においても、媒体摺接面２０ａに形成された防錆剤膜５０によって、大気中や海水雰囲気中、高温高湿下において優れた耐食性を発揮することが可能である。従って、本発明のＧＭＲヘッド２０においては、ＧＭＲ素子２７の腐食等の発生を回避でき、磁気テープ３に対する適切な再生動作を行うことが可能である。
【００８３】
次に、本発明の磁気抵抗効果型磁気ヘッドに適用する磁気記録媒体について、図を参照して説明する。
【００８４】
図６に示す磁気記録媒体６０は、非磁性支持体上に金属磁性材膜を斜方に蒸着させてなる、いわゆる蒸着型の磁気テープであるものとする。
磁気テープは、保磁力、残留磁化、角形比等に優れ、短波長での電磁変換特性に優れるばかりでなく、磁性層の膜厚を極めて薄くできるため、記録減磁や再生時の厚み損失が小さいこと、磁性層中に非磁性材である結合剤を混入する必要がないため、磁性材料の充填密度を高め、大きな磁化を得ることができる等、数々の利点を有している。
上述した磁気テープ用の記録再生装置１では、このような磁気記録媒体６０をテープカセット２の磁気テープ３に用いることで、電磁変換特性を向上させ、より大きな出力を得ることが可能である。
【００８５】
具体的には、磁気記録媒体６０は、テープ状の非磁性支持体６１上に、金属磁性薄膜からなる磁性層６２と、この磁性層６２を保護する保護層６３とが、順次積層された構成を有している。
【００８６】
非磁性支持体６１の材料としては、例えば、ポリエチレンテレフタレート、ポリエチレン−２，６−ナフタレート等のポリエステル類、ポリプロピレン等のポリオレフイン類、セルローストリアセテート、セルロースダイアセテート等のセルロース誘導体、ポリアミド、アラミド樹脂、ポリカーボネート等のプラスチック等が挙げられる。
非磁性支持体６１は、単層構造であっても多層構造であってもよい。また、例えば、非磁性支持体６１の表面には、コロナ放電処理等の表面処理が施されていてもよく、易接着層等の有機物層が下塗層として形成されていてもよい。
【００８７】
磁性層６２は、真空蒸着法、スパッタリング法、ＣＶＤ（Ｃｈｅｍｉｃａｌ Ｖａｐｏｒ Ｄｅｐｏｓｉｔｉｏｎ）法、イオンプレーティング法等、従来公知の手法を用いて金属磁性薄膜を被着することにより成膜することができる。特に、真空蒸着法により成膜されたものが好ましい。
金属磁性薄膜の膜厚は、ラインスピードを変化されることにより制御することが可能であり、残留磁化量は蒸着中の酸素導入量を変化させることにより制御することが可能であり、例えば、１５〜５０ｎｍ程度の膜厚の金属磁性薄膜を確実に成膜することができる。
また、磁性層６２の金属磁性薄膜は、例えば、Ｃｒ下地層上に成膜されてもよい。下地層としては、Ｃｒの他に、ＣｒＴｉ、ＣｒＭｏ、ＣｒＶ等が使用される。また、磁性層６２は、単層構造であっても多層構造であってもよい。
【００８８】
磁気記録媒体６０においては、残留磁化量Ｍｒと磁性層の膜厚ｔとの積Ｍｒ・ｔが、４ｍＡ〜１７ｍＡであることが好ましく、さらには４ｍＡ〜１３ｍＡであることが望ましい。磁気記録媒体６０のＭｒ・ｔが１７ｍＡよりも大きいと、ＧＭＲヘッド２０が飽和して、ＭＲ抵抗変化が線形な領域を外れ、再生波形が歪むという不都合が生じ、また、Ｍｒ・ｔが４ｍＡよりも小さいと、再生出力が小さく、良好なＳＮ比（信号／ノイズ比）が得られなくなるという問題を生じる。よって、Ｍｒ・ｔを、４ｍＡ〜１７ｍＡの範囲にすることで、再生波形の歪みがなく、再生出力が大きく良好なＳＮ比を有するものとなる。
【００８９】
上記Ｍｒおよびｔについては、蒸着時の酸素導入量と非磁性支持体の送りスピード等の成膜条件を制御することによって調整することができる。すなわち、蒸着時の酸素導入量を少なくすることによりＭｒを大きくし、酸素導入量を多くすることによりＭｒを小さくすることができる。
また、蒸着時の非磁性支持体６１の送りスピードを遅くすることにより、膜厚ｔを厚くでき、送りスピードを速くすることにより膜厚ｔを薄くできる。
また、磁性層６２の形成後の表面酸化処理によってもＭｒを調整することができる。
【００９０】
残留磁化量Ｍｒは、１６０ｋＡ／ｍ〜３６０ｋＡ／ｍの範囲であることが好ましい。Ｍｒが３６０ｋＡ／ｍよりも大きいと、磁性粒子の分離が出来ず、磁気的相互作用によりノイズが増大してしまい、また、Ｍｒが１６０ｋＡ／ｍよりも小さいと、Ｃｏ粒子の酸化が進行し、充分な再生出力を得ることが出来ないためである。従って、ノイズを減少させ、充分な再生出力を付与するためには、Ｍｒを１６０ｋＡ／ｍ〜３６０ｋＡ／ｍの範囲に規定することが望ましく、さらには、２００ｋＡ／ｍ〜３４０ｋＡ／ｍの範囲とすることが好ましい。
【００９１】
また、磁気記録媒体６０の表面電気抵抗は、１×１０^３Ω／ｓｑ〜１×１０^７Ω／ｓｑの範囲とすることが好ましい。表面電気抵抗が１×１０^７Ω／ｓｑよりも大きいと、磁気テープ３の走行中などにテープ表面に大きな電荷が帯電し、ＧＭＲヘッド２０と接触した際にＥＳＤ破壊（静電破壊）の原因となり、また表面電気抵抗が１×１０^３Ω／ｓｑよりも小さいと、媒体表面に電荷が流れやすくなり、ＧＭＲヘッド２０と接触したときにヘッドに電流が急激に流れ、ＥＳＤ破壊の原因となるためである。従って、表面電気抵抗を１×１０^３Ω／ｓｑ〜１×１０^７Ω／ｓｑの範囲に規定することにより、金属磁性薄膜表面の帯電、または電流の流れを抑制して、ＧＭＲヘッド２０の静電破壊を防止することができる。
【００９２】
金属磁性薄膜の膜厚ｔは、１５ｎｍ〜５０ｎｍの範囲であることが好ましい。ｔを上記のように規定することにより、磁気記録媒体６０のＭｒ・ｔ、Ｍｒ、表面電気抵抗を、それぞれ上述した範囲に調整することが可能となる。
【００９３】
磁気記録媒体６０においては、面内方向での保磁力Ｈｃは、１００ｋＡ／ｍ〜１６０ｋＡ／ｍの範囲であることが好ましい。保磁力が１００ｋＡ／ｍよりも小さいと、低ノイズ化、高ＳＮ比を実現することができず、また、保磁力が１６０ｋＡ／ｍを超えると、充分な記録が出来なくなり、再生出力が低下してしまうためである。従って、面内方向での保磁力を１００ｋＡ／ｍ〜１６０ｋＡ／ｍの範囲に規定することで、低ノイズ化、高ＳＮ比を実現することができ、高い再生出力が得られる。
【００９４】
上述したように、磁気記録媒体６０においては、残留磁化量Ｍｒと磁性層の膜厚ｔとの積Ｍｒ・ｔが、４ｍＡ〜１７ｍＡの範囲にされているので、再生波形の歪みがなく、再生出力が大きく良好なＳＮ比を有するものとなる。
また、磁気記録媒体６０においては、Ｍｒが１６０ｋＡ／ｍ〜３６０ｋＡ／ｍの範囲にされているので、ノイズを減少させ、充分な再生出力を有するものとなる。
また、磁気記録媒体６０においては、金属磁性薄膜の表面電気抵抗が１×１０^３Ω／ｓｑ〜１×１０^７Ω／ｓｑの範囲にされていることで、金属磁性薄膜表面の帯電、または電流の流れを抑制して、ＧＭＲヘッド２０の静電破壊を防止することができる。従って本発明の磁気記録媒体６０においては、ノイズの低減化が図られ、高い再生出力、および良好なＳＮ比を有すると共に、ＧＭＲヘッド２０で再生した場合のヘッドの飽和及び静電気破壊を防止することが可能である。
【００９５】
保護層６３は、通常の金属磁性薄膜用の保護膜として使用されるものであれば、如何なる材料であってもよく、例えばダイヤモンドライクカーボン（ＤＬＣ）や、ＣｒＯ_２、Ａｌ_２Ｏ_３、ＢＮ、Ｃｏ酸化物、ＭｇＯ、ＳｉＯ_２、Ｓｉ_３Ｏ_４、ＳｉＮ_ｘ、ＳｉＣ、ＳｉＮ_ｘ−ＳｉＯ_２、ＺｒＯ_２、ＴｉＯ_２、ＴｉＣ等が挙げられる。また、これらの単層膜であってもよく、多層膜あるいは複合膜であってもよい。
なお、上述した表面電気抵抗は、例えば、この金属磁性薄膜上に形成されるダイヤモンドライクカーボン（ＤＬＣ）保護膜の膜厚等を制御することによって調整することも可能である。
【００９６】
磁気記録媒体６０には、磁性層６２が形成された側の主面を被覆するトップコート層６４として、ＧＭＲヘッド２０の媒体摺接面２０ａに形成された防錆剤膜５０と同一材料からなる防錆剤膜を形成してもよい。
【００９７】
トップコート層６４を形成する防錆剤膜は、ＧＭＲヘッド２０の媒体摺接面２０ａに防錆剤膜５０を転写するために、磁気記録媒体６０のＧＭＲヘッド２０が摺接される側の主面に所定の膜厚で形成する。
【００９８】
従って、磁気記録媒体６０においては、ＧＭＲヘッド２０が摺接されることによって、ＧＭＲヘッド２０の媒体摺接面２０ａに防錆剤膜が転写され、この転写された防錆剤膜（図３中の５０）によってＧＭＲ素子２７の腐食等の発生が回避される。
【００９９】
また、磁気記録媒体６０には、磁性層６２が形成された主面とは反対側の主面を被覆するバックコート層６５として、上述したＧＭＲヘッド２０の媒体摺接面２０ａに形成された防錆剤膜と同一材料からなる防錆剤膜が所定の膜厚で形成されている。
【０１００】
このバックコート層６５は、図１中に示した供給リール４の巻回されることによって、バックコート層６５と対向するトップコート層６４に防錆剤膜を転写する。従って、このバックコート層６５を形成する防錆剤膜は、磁気記録媒体６０にＧＭＲヘッド２０が摺接されることによって、最終的にＧＭＲヘッド２０の媒体摺接面２０ａに転写される。
【０１０１】
なお、これらトップコート層６４およびバックコート層６５を構成する防錆剤膜の膜厚は、ＧＭＲヘッド２０の媒体摺接面２０ａに形成された防錆剤膜と同様に、１〜５００Åの範囲とすることが好ましく、さらには２〜２００Åの範囲、さらには５〜１００Åの範囲とすることが望ましい。
【０１０２】
上述したように、本発明の磁気抵抗効果型磁気ヘッドに適用する磁気記録媒体６０は、ＧＭＲヘッド２０が摺接された際に、ＧＭＲヘッド２０の媒体摺接面２０ａに防錆剤膜を、直接または間接的に転写するものであることから、ＧＭＲヘッド２０の媒体摺接面２０ａに防錆剤膜５０が形成されていない場合においても、転写された防錆剤膜によって、ＧＭＲ素子２７の腐食等の発生を回避することが可能である。
また、ＧＭＲヘッド２０の媒体摺接面２０ａに形成された防錆剤膜５０が摩耗により減少した場合でも、磁気記録媒体６０から防錆剤膜が直接または間接的に転写されることによって、防錆剤膜５０を所望の膜厚に維持することが可能である。従って、磁気テープ用記録再生装置１に装填されるテープカセット２の磁気テープ３として特に好適なものである。
【０１０３】
なお、磁気記録媒体６０は、上述した構成に限定されるものではなく、必要に応じて磁性層６２上に保護層６３が形成されていない構成としてもよい。この場合、磁性層６２上に防錆剤膜（トップコート層６４）が直接被覆される構成となり、この防錆剤膜によって磁性層６２の酸化や腐食等の発生を防ぐことも可能である。
また、磁気記録媒体６０は、その両面に防錆剤膜が形成された構成に限らず、磁性層６２が形成された側の主面のみに防錆剤膜を形成したものや、磁性層６２が形成された側の主面とは反対側の主面のみに防錆剤膜を形成したものであってもよい。
【０１０４】
上述したように、磁気テープ用の記録再生装置１においては、本発明のＧＭＲヘッド２０と磁気記録媒体６０とを組み合わせることで、これまでにない高密度記録再生システムを構築することが可能である。そして、この磁気テープ用の記録再生装置１においては、ヘリカルスキャン方式により磁気記録媒体６０に対してＧＭＲヘッド２０を摺接しながら磁気信号の検出を行った際でも、ＧＭＲヘッド２０の媒体摺接面２０ａの腐食等の発生を防止することができる。
【０１０５】
【実施例】
次に、本発明の具体的な実施例について説明する。
先ず、上述した防錆剤膜を媒体摺接面に形成したＧＭＲヘッドと、防錆剤膜を媒体摺接面に形成しなかったＧＭＲヘッドとをそれぞれ作製し、磁気テープ用の記録再生装置を用いて磁気テープを走行させずに、これらＧＭＲヘッドを放置した場合のヘッドの耐食性について調べた。
【０１０６】
ここでは、第１の磁気ヘッドとして、下地層となるＴａ膜と、磁化自由層となるＮｉＦｅ膜、及びＣｏＮｉＦｅ膜と、非磁性層となるＣｕ膜と、磁化固定層となるＮｉＦｅ膜と、反強磁性層となるＰｔＭｎ膜と、保護層となるＴａ膜とが順次積層されてなるスピンバルブ膜を備えるＧＭＲヘッドを作製し、第２の磁気ヘッドとして、下地層となるＴａ膜と、磁化自由層となるＮｉＦｅ膜及びＣｏＮｉＦｅ膜と、非磁性層となるＣｕＡｕ膜と、磁化固定層となるＮｉＦｅ膜と、反強磁性層となるＰｔＭｎ膜と、保護層となるＴａ膜とが順次積層されてなるスピンバルブ膜を備えるＧＭＲヘッドと作製した。
【０１０７】
上記第１および第２の磁気ヘッドについて、媒体摺接面に防錆剤膜を形成しなかった場合と、媒体摺接面にカルボン酸アミン塩化合物からなる防錆剤膜を形成した場合とで、それぞれ塩水試験による腐食発生の有無についての評価を行った。
【０１０８】
評価結果を下記表１に示す。なお、表２において、◎は、本腐食試験において腐食の発生がなく優れた耐食性が確認された場合を示し、○は、本腐食試験において腐食の発生が確認されなかった場合を示し、×は、本腐食試験において腐食の発生が確認された場合を示す。
【０１０９】
【表１】

【０１１０】
上記表１に示す評価結果から、第１の磁気ヘッドおよび第２の磁気ヘッドにおいては、いずれも防錆剤膜を形成しなかった場合に腐食が発生した。
これに対して、媒体摺接面に防錆剤膜を形成した場合には、いずれも腐食の発生がなく、優れた耐食性を示した。
【０１１１】
次に、防錆剤膜を媒体摺接面に形成したＧＭＲヘッドと、防錆剤膜を媒体摺接面に形成しなかったＧＭＲヘッドとを作製すると共に、防錆剤膜を表面に形成した磁気テープと、防錆剤膜を表面に形成しなかった磁気テープとを作製し、磁気テープ用の記録再生装置において、ＧＭＲヘッドを磁気テープに摺接させて５パス走行させた後の、腐食発生の有無についての評価を行った。
【０１１２】
なお、磁気ヘッドとしては、上述した第１の磁気ヘッドを用い、防錆剤膜として、上記表１に示したカルボン酸アミン塩化合物１を用い、磁気テープとしては、磁性層が形成された側の主面のみ防錆剤膜を塗布により形成した構成のものを用いた。
【０１１３】
評価結果を下記表２に示す。なお、表２においては、◎は、本腐食試験において腐食の発生がなく優れた耐食性が確認された場合を示し、○は、本腐食試験において腐食の発生が確認されなかった場合を示し、×は、本腐食試験において腐食の発生が確認された場合を示す。
【０１１４】
【表２】

【０１１５】
表２に示すように、防錆剤膜を媒体摺接面に形成しなかったＧＭＲヘッドを、防錆剤膜を表面に形成しなかった磁気テープに摺接させた場合には、腐食が発生することがわかる。
これに対して、防錆剤膜を媒体摺接面に形成したＧＭＲヘッドを、防錆剤膜を表面に形成しなかった磁気テープに摺接させた場合、並びに、防錆剤膜を媒体摺接面に形成しなかったＧＭＲヘッドを、防錆剤膜を表面に形成した磁気テープに摺接させた場合には、腐食の発生がなく、特に、防錆剤膜を媒体摺接面に形成したＧＭＲヘッドを、防錆剤膜を表面に形成した磁気テープに摺接させた場合には、優れた耐食性を示すことがわかる。
【０１１６】
次に、防錆剤膜を表面に形成しなかった磁気テープと、磁性層が形成された側の主面のみ防錆剤膜を形成した磁気テープと、磁性層が形成された側の主面とは反対側の主面のみ防錆剤膜を形成した磁気テープと、両面に防錆剤膜を形成した磁気テープとをそれぞれ作製し、これら磁気テープに防錆剤膜が媒体摺接面に形成されていないＧＭＲヘッドを摺接させて５パス走行させた際の腐食発生の有無についての評価を行った。
【０１１７】
なお、磁気ヘッドとして、上述した第１の磁気ヘッドを用い、防錆剤膜としては、表１に示したカルボン酸アミン塩化合物５を用いた。
【０１１８】
評価結果を下記表３に示す。なお、表３においては、◎は、本腐食試験において腐食の発生がなく優れた耐食性が確認された場合を示し、○は、本腐食試験において腐食の発生が確認されなかった場合を示し、×は、本腐食試験において腐食の発生が確認された場合を示す。
【０１１９】
【表３】

【０１２０】
上記表３に示すように、防錆剤膜を表面に形成しなかった磁気テープにＧＭＲヘッドを摺接させた場合には、腐食が発生することがわかる。
これに対して、磁性層が形成された側の主面のみ防錆剤膜を形成した磁気テープにＧＭＲヘッドを摺接させた場合、並びに磁性層が形成された側の主面とは反対側の主面のみ防錆剤膜を形成した磁気テープにＧＭＲヘッドを摺接させた場合には、腐食の発生がなく、特に、両面に防錆剤膜を形成した磁気テープにＧＭＲヘッドを摺接させた場合には、優れた耐食性を示すことがわかる。
【０１２１】
次に、磁性層が形成された側の主面に防錆剤膜を形成しなかった磁気テープと、磁性層が形成された側の主面に防錆剤膜を形成した磁気テープとを、それぞれ作製し、これら磁気テープの、６０℃×９０％ＲＨ雰囲気下で１週間大気試験後の腐食発生の有無についての評価を行った。
【０１２２】
なお、ここでは、作製された磁気テープの残留磁化量Ｍｒは２８５ｍＡ／ｍであり、金属磁性薄膜の膜厚ｔは４０ｎｍであり、それらの積Ｍｒ・ｔは、１２ｍＡであり、保磁力Ｈｃは、１２０ｋＡ／ｍであった。
また、防錆剤膜としては、上記表１に示したカルボン酸アミン塩化合物１、５を適用した。
【０１２３】
評価結果を下記表４に示す。なお、表４においては、○は、本腐食試験において腐食の発生が確認されなかった場合を示し、×は、本腐食試験において腐食の発生が確認された場合を示す。
【０１２４】
【表４】

【０１２５】
上記表４の評価結果から、磁性層が形成された側の主面に防錆剤膜を形成しなかった磁気テープにおいては、腐食が発生することがわかる。
これに対して、磁性層が形成された側の主面に防錆剤膜を形成した磁気テープにおいては、腐食の発生がなく、優れた耐食性を示すことがわかる。
【０１２６】
【発明の効果】
本発明の磁気抵抗効果型磁気ヘッドによれば、磁気抵抗効果素子の媒体摺接面に、カルボン酸アミン塩化合物を含有する防錆剤膜が形成されているので、磁気抵抗効果素子の媒体摺接面に腐食等が発生することが防止でき、磁気記録媒体に対する適切な再生動作を行うことが可能となった。
【０１２７】
また、本発明に係る記録再生装置によれば、磁気テープに磁気抵抗効果型磁気ヘッドが摺接することによって、カルボン酸アミン塩化合物を含有する防錆剤膜が磁気抵抗効果素子の媒体摺接面に転写されることから、磁気記録媒体から転写された防錆剤膜によって媒体摺接面が被覆され、磁気抵抗効果型磁気ヘッドの磁気抵抗効果素子に腐食等が発生することを防ぐことが可能となった。したがって、磁気抵抗効果型磁気ヘッドと磁気テープとを組み合わせることにより、磁気抵抗効果型磁気ヘッドの腐食等の発生を防ぎつつ、磁気テープの更なる高記録密度化が可能となった。
【図面の簡単な説明】
【図１】磁気テープ用の記録再生装置の概略平面図を示す。
【図２】記録再生装置を構成するヘッドドラムの概略斜視図を示す。
【図３】本発明の磁気抵抗効果型磁気ヘッドの概略斜視図を示す。
【図４】ＧＭＲヘッドを媒体摺接面側から見た端面図を示す。
【図５】（ａ） ボトム型のスピンバルブ膜の概略断面図を示す。
（ｂ） トップ型のスピンバルブ膜の概略断面図を示す。
（ｃ） デュアル型のスピンバルブ膜の概略断面図を示す。
【図６】本発明の記録再生装置に適用する磁気記録媒体の概略断面図を示す。
【符号の説明】
１……磁気テープ装置、２……テープカセット、３……磁気テープ、４……供給リール、５……巻取リール、６……装置本体、７ａ〜７ｆ……ガイドローラ、８……ピンチローラ、９……キャップスタン、１０……キャップスタンモータ、１１ａ，１１ｂ……記録用磁気ヘッド、１２ａ，１２ｂ……再生用磁気ヘッド、１３……ヘッドドラム、１４……回転ドラム、１５……固定ドラム、１６……駆動モータ、２０……磁気抵抗効果型磁気ヘッド、２０ａ……媒体摺接面、２１…… 第１のコア部材、２２……保護膜、２３……第２のコア部材、２４，２５……シールド層、２６……ギャップ層、２７……ＧＭＲ素子、２８ａ，２８ｂ……永久磁石膜、２９ａ，２９ｂ……低抵抗膜、３０ａ，３０ｂ……導体部、３１ａ，３１ｂ……外部接続用端子、４０……スピンバルブ膜、４１……下地層、４２……反強磁性層、４３……磁化固定層、４４……非磁性層、４５……磁化自由層、５０……防錆剤膜、６０……磁気記録媒体、６１……非磁性支持体、６２……磁性層、６３……保護層、６４……トップコート層、６５……バックコート層[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a magneto-resistive magnetic head having a magneto-resistive element as a magneto-sensitive element for detecting a magnetic signal while sliding on a magnetic recording medium, and a magnetic recording medium comprising a magneto-resistive magnetic head and a magnetic recording medium. The present invention relates to a recording / reproducing apparatus in which a tape is combined.
[0002]
[Prior art]
Conventionally, inductive magnetic heads and magnetoresistive magnetic heads have been put to practical use for recording and reproducing information signals on and from a magnetic recording medium (for example, see Patent Documents 1 and 2).
A magneto-resistance effect element (hereinafter, referred to as an MR element) constituting a magneto-resistance effect type magnetic head utilizes a so-called magneto-resistance effect in which a resistance value changes depending on the magnitude and direction of an external magnetic field, and is a magnetic recording medium. It has a function as a magneto-sensitive element for detecting a signal magnetic field from the sensor. A magnetic head having such an MR element is generally called a magnetoresistive head (hereinafter, referred to as an MR head).
[0003]
As the MR element, an element utilizing the anisotropic magnetoresistance effect has been conventionally used. However, an element exhibiting a larger MR ratio is desired because the magnetoresistance ratio (MR ratio) is small. Was. Therefore, in recent years, a giant magnetoresistive element (hereinafter, referred to as a GMR element) using a spin valve film has been proposed as an MR element exhibiting a larger MR ratio.
[0004]
The GMR element has a spin-valve film in which a non-magnetic layer is sandwiched between a pair of magnetic layers, and the conductance of a so-called sense current flowing in an in-plane direction with respect to the spin-valve film is equal to the conductance of the pair of magnetic layers. It utilizes the so-called giant magnetoresistance effect, which changes depending on the relative angle of magnetization.
Specifically, the spin valve film is composed of an antiferromagnetic layer, a magnetization fixed layer in which magnetization is fixed in a predetermined direction by an exchange coupling magnetic field acting between the antiferromagnetic layer, and a magnetization direction according to an external magnetic field. And a nonmagnetic layer that magnetically isolates the magnetization fixed layer and the magnetization free layer from each other.
[0005]
In the GMR element using the spin valve film, when an external magnetic field is applied, the magnetization direction of the magnetization free layer changes according to the magnitude and direction of the external magnetic field. When the magnetization direction of the magnetization free layer is opposite (antiparallel) to the magnetization direction of the magnetization fixed layer, the resistance value of the sense current flowing through the spin valve film becomes maximum. On the other hand, when the magnetization direction of the magnetization free layer is in the same direction (parallel) as the magnetization direction of the magnetization fixed layer, the resistance value of the sense current flowing through the spin valve film becomes minimum.
[0006]
Accordingly, in a magnetic head including such a GMR element (hereinafter, referred to as a GMR head), when a constant sense current is supplied to the GMR element, the magnetic head flows through the GMR element according to a signal magnetic field from a magnetic recording medium. The voltage value of the sense current changes, and a magnetic signal from the magnetic recording medium can be read by detecting the change in the voltage value of the sense current.
[0007]
On the other hand, as a magnetic recording medium, conventionally, a powder magnetic material such as an oxide magnetic powder or an alloy magnetic powder is coated on a non-magnetic support by an organic binder such as a vinyl chloride-vinyl acetate copolymer, a polyester resin, and a polyurethane resin. A so-called coating type magnetic recording medium produced by applying and drying a magnetic paint dispersed therein is widely used.
[0008]
In addition, as the demand for high-density recording increases, non-magnetic materials such as Co-Ni, Co-Cr, Co, etc. are plated by plating or vacuum thin film forming means (vacuum vapor deposition, sputtering, ion plating, etc.). A so-called metal magnetic thin film type magnetic recording medium directly attached to a support has been proposed and attracts attention.
[0009]
Such a metal magnetic thin film type magnetic recording medium is excellent in coercive force, remanent magnetization, squareness ratio, etc., and is excellent not only in electromagnetic conversion characteristics at a short wavelength, but also because the thickness of a magnetic layer can be extremely thin. Since the thickness loss at the time of demagnetization and reproduction is small, and it is not necessary to mix a binder which is a non-magnetic material in the magnetic layer, the packing density of the magnetic material can be increased and a large magnetization can be obtained. Has advantages.
[0010]
Furthermore, in order to improve the electromagnetic conversion characteristics of this type of magnetic recording medium and obtain a larger output, a so-called evaporation tape in which a metal magnetic material is obliquely evaporated on a non-magnetic support has been proposed. It has been put to practical use as a magnetic tape for high image quality VTRs and digital VTRs.
[0011]
Incidentally, the above-mentioned GMR head is used in a magnetic disk device such as a hard disk drive. The hard disk drive has, for example, a structure in which a GMR head is mounted on a head slider attached to the tip of a suspension. In this hard disk drive, the GMR head mounted on the head slider was recorded on the magnetic disk while the head slider floated above the signal recording surface of the magnetic disk in response to the airflow generated by the rotation of the magnetic disk. By reading the magnetic signal, a reproducing operation for the magnetic disk is performed.
[0012]
In recent years, it has been proposed to use a GMR head not only in such a magnetic disk device but also in a magnetic tape device such as a tape streamer in order to achieve higher recording density.
For example, a tape streamer adopting a helical scan system has a structure in which a GMR head is arranged on the outer peripheral portion of a rotary drum so as to be oblique to an azimuth angle with respect to a direction substantially perpendicular to a running direction of a magnetic tape. ing. In this tape streamer, the rotating drum is driven to rotate while the magnetic tape runs obliquely with respect to the rotating drum, and the GMR head mounted on the rotating drum is recorded on the magnetic tape while slidingly contacting the magnetic tape. By reading the magnetic signal, a reproducing operation for the magnetic tape is performed.
[0013]
In a magnetic tape device combining such a GMR head and a vapor-deposited tape, it is expected that the recording density will be drastically increased more than before.
[0014]
[Patent Document 1]
JP-A-11-149612 (pages 4, 5; FIG. 1)
[Patent Document 2]
Japanese Patent Application Laid-Open No. Hei 10-302225
Incidentally, in the above-described tape streamer, it is preferable to reduce the distance between the GMR head and the magnetic tape, that is, the so-called spacing, and the surface of the magnetic tape is becoming mirror-finished.
[0016]
However, as the surface of the magnetic tape becomes mirror-finished, the contact area between the magnetic tape and the outer peripheral surface of the rotating drum increases, and the frictional force acting between the magnetic tape and the rotating drum during running increases, and Sticking to the rotating drum may occur, making smooth running of the magnetic tape difficult.
[0017]
In view of such a problem, the surface of the magnetic tape is provided with countless minute projections made of SiO ₂ filler, organic filler, or the like, and these small projections reduce the contact area with the outer peripheral surface of the rotating drum. In addition, the frictional force acting between the magnetic tape and the rotating drum is reduced.
Note that such fine projections can be formed by attaching the above-described filler to the surface of a base film that is to be a magnetic tape and coating the magnetic film thereon. In addition, a protective film such as a DLC film or the like for preventing the occurrence of oxidation, corrosion, or the like in the atmosphere or in a seawater atmosphere or under high temperature and high humidity is usually formed on the surface of the magnetic tape.
[0018]
By the way, in the hard disk drive described above, the reproducing operation is performed in a state where the GMR head is not in contact with the signal recording surface of the magnetic disk.
Further, Cu is usually used for the nonmagnetic layer constituting the spin valve film of the GMR head, and a DLC (Diamond Like Carbon) is provided on the medium facing surface of the GMR head facing the magnetic disk in order to prevent corrosion. ) A protective film such as a film is formed.
[0019]
On the other hand, in the above-described tape streamer, since the reproducing operation is performed while the GMR head is in contact with the magnetic tape, the protective film is provided on the medium sliding surface of the GMR head which is in sliding contact with the magnetic tape as described above. Is formed, the protective film formed on the medium sliding contact surface of the GMR head is worn due to the contact with the minute protrusions and the protective film formed on the surface of the magnetic tape during the reproducing operation. .
Further, since the protective film formed on the surface of the GMR head that slides on the medium provides spacing with the magnetic tape, it causes the short-wavelength recording / reproducing characteristics of the GMR head to deteriorate.
[0020]
Therefore, in a magnetic tape device such as the above-described tape streamer, it is inappropriate to form a protective film on the medium sliding surface of the GMR head. For this reason, in the conventional magnetic tape device, the medium sliding surface of the GMR head comes into direct contact with the atmosphere, and there has been a problem that corrosion or the like easily occurs under high temperature and high humidity or in a seawater atmosphere.
The sensitivity of the GMR head is determined by the sense current flowing through the spin valve film. Each layer of the spin valve film is formed to a thickness on the order of nm, and even if slight corrosion occurs in each layer, the electric resistance of each layer changes. Accordingly, the occurrence of corrosion on the medium sliding surface of the GMR head significantly deteriorates the head characteristics of the GMR head.
[0021]
Further, since the GMR head has extremely high sensitivity, if the signal magnetic field received from the magnetic recording medium is large, head saturation causing noise is caused. Therefore, when the GMR head is used as a reproducing head of the above-described magnetic tape device, the value of the product Mr · t of the residual magnetization amount Mr of the magnetic recording medium and the thickness t of the magnetic layer must be adjusted. Instead, attempts have been made to reduce the thickness t of the magnetic layer.
[0022]
However, in a magnetic recording medium, a part of the above-mentioned protective film may be scraped due to sliding contact with the GMR head, and when the thickness of the magnetic layer is reduced, oxidation, corrosion and the like are easily generated. Would. In this case, the reproduction output in the magnetic tape device using the above-described GMR head is significantly reduced.
[0023]
As a method for preventing corrosion of the magnetic head, for example, in Patent Document 1 described above, a groove portion for separating the base end side and the front end side of the magnetic core half is provided, and a rust inhibitor is stored in the groove portion. Things have been suggested.
However, in this case, a new processing step for forming the groove on the magnetic head is required, which causes a problem that the manufacturing cost increases.
[0024]
Further, as a method for preventing the wear of the magnetoresistive film of the magnetic head, for example, a method in which a hard coating such as a DLC protective layer is formed on the sliding surface of the magnetoresistive magnetic head described in Patent Document 2 described above. Has been proposed.
However, in this example, particularly when applied to a magnetic tape medium, there is a problem that a spacing loss corresponding to the thickness of the protective layer is generated and the output is reduced.
[0025]
[Problems to be solved by the invention]
Therefore, in the present invention, in view of such a conventional problem, it is possible to prevent the occurrence of corrosion or the like on the medium sliding contact surface of the magnetoresistive effect element that detects a magnetic signal while sliding on the magnetic recording medium, It is intended to provide a magnetoresistive head capable of performing an appropriate reproducing operation on a recording medium.
[0026]
Further, in the present invention, by combining the above-described magneto-resistance effect type magnetic head and a magnetic tape as a magnetic recording medium, it is possible to prevent the occurrence of corrosion and the like of the magneto-resistance effect type magnetic head, It has been decided to provide a magnetic tape recording / reproducing apparatus capable of further increasing the recording density.
[0027]
[Means for Solving the Problems]
A magnetoresistive head according to the present invention includes a magnetoresistive element as a magneto-sensitive element that detects a magnetic signal while sliding on a magnetic recording medium. It is assumed that a rust preventive film containing an acid amine salt compound is formed.
[0028]
According to the magnetoresistance effect type magnetic head of the present invention, the rust preventive film containing the amine carboxylate compound is formed on the medium sliding contact surface of the magnetoresistance effect element. Even when a protective film is not formed on the surface to be formed, excellent corrosion resistance can be obtained.
[0029]
Further, the recording / reproducing apparatus for a magnetic tape according to the present invention is a magnetic tape, a tape running means for running the magnetic tape, and a magnetic sensing element for detecting a magnetic signal while slidingly contacting the magnetic tape run by the tape running means. And a magnetoresistive effect type magnetic head having a magnetoresistive effect element as the main surface, and a main surface of the magnetic tape on which the magnetoresistive effect magnetic head is slid, and / or a side opposite to the main surface. A rust preventive film containing a carboxylic acid amine salt compound is formed on the main surface, and the rust preventive film is brought into sliding contact with the magnetic tape by a magnetic resistance effect type magnetic head. It is to be transferred to the contact surface.
[0030]
ADVANTAGE OF THE INVENTION According to the recording / reproducing apparatus which concerns on this invention, a rust preventive agent film containing a carboxylic acid amine salt compound is transcribe | transferred to the medium sliding contact surface of a magnetoresistive effect element by a magnetic-resistive effect type magnetic head sliding contacting a magnetic tape. Therefore, the sliding surface of the medium is covered with the rust preventive film, and the occurrence of corrosion and the like in the magnetoresistive element is avoided.
[0031]
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, a recording / reproducing apparatus applied to a magneto-resistance effect type magnetic head and a magnetic tape according to the present invention will be described in detail with reference to the drawings.
[0032]
A recording device for a magnetic tape to which the magnetoresistive head according to the present invention is applied will be described.
A recording / reproducing apparatus 1 for a magnetic tape shown in FIG. 1 records and / or reproduces an information signal on a magnetic tape 3 stored in a tape cassette 2 by a helical scan method.
In the tape cassette 2, a supply reel 4 for supplying the magnetic tape 3 and a take-up reel 5 for winding the magnetic tape 3 supplied from the supply reel 4 are rotatably provided.
[0033]
The recording / reproducing apparatus 1 includes an apparatus main body 6 to which the tape cassette 2 can be attached and detached. The apparatus main body 6 has a structure in which the magnetic tape 3 is routed between the supply reel 4 and the take-up reel 5 when the tape cassette 2 is loaded. A plurality of guide rollers 7a to 7f are provided.
[0034]
Also, between the guide roller 7e and the guide roller 7f, as a tape running means, a pinch roller 8 on which the magnetic tape 3 is hung, a capstan 9 for holding the magnetic tape 3 together with the pinch roller 8, and a capstan 9 9 is provided.
When the magnetic tape 3 is sandwiched between the pinch roller 8 and the capstan 9, the capstan 9 is rotated by the capstan motor 10 in the direction of arrow A in FIG. The vehicle travels at a constant speed and tension in the direction B.
[0035]
A head drum 13 on which a pair of recording magnetic heads 11a and 11b and a pair of reproduction magnetic heads 12a and 12b are mounted is provided between the guide roller 7c and the guide roller 7d. ing.
The magnetic tape 3 is pulled out of the tape cassette 2 by the above-described plurality of guide rollers 7a to 7f, and wound around the head drum 13 in a helical shape in an angle range of about 180 ° in the direction of arrow B in FIG. Be run.
[0036]
As shown in FIGS. 1 and 2, the head drum 13 includes a set of a rotating drum 14 and a fixed drum 15 that are vertically combined, and a driving motor 16 that drives the rotating drum 14 to rotate. It is arranged in a state where it is slightly inclined with respect to the base with its axes aligned.
[0037]
The fixed drum 15 constituting the lower drum is fixedly supported on the base of the apparatus main body 6, and a lead guide 17 for guiding the magnetic tape 3 is formed on a cylindrical outer peripheral surface 15a. The magnetic tape 3 runs obliquely with respect to the rotation direction of the rotary drum 14 along the lead guide 17.
[0038]
On the other hand, the rotating drum 14 constituting the upper drum is rotatably supported by a fixed drum 15 having substantially the same diameter whose central axis is aligned, and is driven by a drive motor 16 disposed below the fixed drum 15. It is rotationally driven in the direction of arrow C in FIGS. A pair of recording magnetic heads 11 a and 11 b for performing a signal recording operation on the magnetic tape 3 and a signal A pair of reproducing magnetic heads 12a and 12b for performing a reproducing operation are attached.
[0039]
The pair of recording magnetic heads 11a and 11b are inductive magnetic heads in which a pair of magnetic cores are joined via a magnetic gap and a coil is wound around the magnetic core.
The pair of recording magnetic heads 11a and 11b are opposed to each other at a position where the center angle between them with respect to the rotation center of the rotary drum 14 is 180 °.
The pair of recording magnetic heads 11 a and 11 b are provided so as to slightly protrude from the outer peripheral surface of the rotary drum 14 such that the respective recording gaps extend from the outer peripheral surface of the rotary drum 14 to the outside. The pair of recording heads 11a and 11b have their recording gaps oblique to the direction substantially perpendicular to the running direction of the magnetic tape 3 according to the azimuth angle so that azimuth recording can be performed on the magnetic tape 3. It is arranged to become.
The pair of recording heads 11a and 11b are set such that the azimuth angles thereof are opposite to each other.
[0040]
On the other hand, the pair of reproducing magnetic heads 12a and 12b are magnetoresistive heads having a magnetoresistive element as a magnetosensitive element for detecting a signal from the magnetic tape 3.
The pair of reproducing magnetic heads 12a and 12b are arranged to face each other at a position where the center angle between them with respect to the rotation center of the rotary drum 14 is 180 °.
Further, the pair of reproducing magnetic heads 12a and 12b are provided so as to slightly protrude from the outer peripheral surface of the rotary drum 14 so that the respective reproducing gaps reach the outside from the outer peripheral surface of the rotary drum 14. The pair of reproducing magnetic heads 12a and 12b have a reproducing gap in a direction substantially perpendicular to the running direction of the magnetic tape 3 so that a signal recorded azimuthally on the magnetic tape 3 can be reproduced. They are arranged obliquely according to the azimuth angle. The pair of reproducing magnetic heads 12a and 12b are set such that their azimuth angles are opposite to each other.
[0041]
In the head drum 13, while the magnetic tape 3 wound on the outer peripheral surfaces 14a, 15a of the rotary drum 14 and the fixed drum 15 travels in the direction of arrow B in FIG. 2, the pair of recording magnetic heads 11 a and 11 b and the pair of reproducing magnetic heads 12 a and 12 b mounted on the rotary drum 14 are slidably in contact with the magnetic tape 3 while rotating in the direction indicated by the arrow C in FIG. Perform a recording operation or a reproducing operation.
[0042]
Specifically, at the time of recording, one recording magnetic head 11a forms a recording track with a predetermined track width while applying a magnetic field corresponding to a recording signal to the magnetic tape 3, and the other recording magnetic head 11b A recording track is formed with a predetermined track width while applying a magnetic field according to a recording signal adjacent to the recording track.
When the recording magnetic heads 11 a and 11 b repeatedly form recording tracks on the magnetic tape 3, signals are continuously recorded on the magnetic tape 3.
[0043]
On the other hand, at the time of reproduction, one reproducing magnetic head 12a detects a signal magnetic field from the recording track recorded by the recording magnetic head 11a, and the other reproducing magnetic head 12b detects the magnetic tape 3 with respect to the magnetic tape 3. A signal magnetic field is detected from a recording track recorded by the magnetic head 11b.
When the reproducing magnetic heads 12a and 12b repeatedly detect the signal magnetic field from the recording tracks, the signals recorded on the magnetic tape 3 are continuously reproduced.
[0044]
Next, the magnetoresistive head 20 of the present invention will be described in detail with reference to FIGS.
[0045]
The magnetoresistive head 20 includes a giant magnetoresistive element (hereinafter, referred to as a GMR element) using a spin valve film as a magnetic sensing element for detecting a magnetic signal from a magnetic recording medium. This is a resistance effect type magnetic head (hereinafter, referred to as a GMR head).
[0046]
The GMR head 20 has a higher sensitivity than an inductive magnetic head or an anisotropic magnetoresistive magnetic head that performs recording and reproduction using electromagnetic induction, has a large reproduction output, and is suitable for high-density recording. Therefore, in the recording / reproducing apparatus 1 for a magnetic tape described above, further high-density recording is achieved by using the GMR head 20 for the pair of magnetic heads for reproduction 12a and 12b.
[0047]
Specifically, as shown in FIG. 4, the pair of reproducing magnetic heads 12a and 12b are provided on the first core member 21 with a shield layer 24 by a thin film forming technique such as plating, sputtering, or vapor deposition. , A GMR element 27, a gap layer 26, and a shield layer 25, and have a structure in which a second core member 23 is attached via a protective film 22.
The pair of reproducing magnetic heads 12a and 12b have a medium sliding surface 20a that slides on the magnetic tape 3 and a curved surface curved in a substantially arc shape along the running direction of the magnetic tape 3 indicated by an arrow B in FIG. Has become.
The GMR head 20 is arranged such that the reproduction gap facing the outside from the medium sliding contact surface 20a is oblique to the direction substantially perpendicular to the running direction of the magnetic tape 3 according to the azimuth angle θ.
[0048]
The pair of reproducing magnetic heads 12a and 12b have the same configuration except that their azimuth angles θ have opposite phases. Therefore, in the following description, the pair of reproducing magnetic heads 12a and 12b will be collectively described as a GMR head 20.
[0049]
The GMR head 20 has a structure in which a GMR element 27 is sandwiched between a pair of upper and lower magnetic shield layers 24 and 25 via a gap layer 26.
[0050]
The pair of magnetic shield layers 24 and 25 are formed of a soft magnetic film having a width sufficient to magnetically shield the GMR element 27. Of the signal magnetic fields of the above, it functions so that a magnetic field not to be reproduced is not drawn into the GMR element 27. That is, in the GMR head 20, a signal magnetic field not to be reproduced with respect to the GMR element 27 is guided to the pair of magnetic shield layers 24 and 25, and only the signal magnetic field to be reproduced is guided to the GMR element 27. Thereby, the frequency characteristics and the reading resolution of the GMR element 27 are improved.
[0051]
The gap layer 26 is formed of a non-magnetic non-conductive film that magnetically isolates the GMR element 27 from the pair of magnetic shield layers 24 and 25, and the gap between the pair of magnetic shield layers 24 and 25 and the GMR element 27. Is the gap length.
[0052]
The GMR element 27 is formed of a spin valve film 40, and the conductance of the sense current flowing in the in-plane direction with respect to the spin valve film 40 changes depending on the relative angle of the magnetization of the pair of magnetic layers. It uses the resistance effect.
[0053]
As the spin valve film 40, for example, as shown in FIG. 5A, an underlayer 41, an antiferromagnetic layer 42, a magnetization fixed layer 43, a nonmagnetic layer 44, a magnetization free layer 45, and a protection layer 46 are formed. As shown in FIG. 5B, a bottom type spin valve film 40a having a sequentially laminated structure, or an underlayer 41, a magnetization free layer 45, a nonmagnetic layer 44, a magnetization fixed layer 43, and an antiferromagnetic layer 42, as shown in FIG. , And a protective layer 46 are sequentially stacked, as shown in FIG. 5C, a top type spin valve film 40b having a structure in which an underlayer 41, an antiferromagnetic layer 42, a magnetization fixed layer 43, a nonmagnetic layer 44, a magnetization free layer 45, a nonmagnetic layer 44, a magnetization fixed layer 43, an antiferromagnetic layer 42, and a protective layer 46 are sequentially stacked.
[0054]
The underlayer 41 and the protective layer 46 are for suppressing an increase in the specific resistance of the spin valve film 40, and are formed of, for example, Ta.
[0055]
The antiferromagnetic layer 42 is preferably formed of PtMn having excellent corrosion resistance. The antiferromagnetic layer 42 can be formed of NiO having excellent corrosion resistance, IrMn, CrMnPt, α-Fe ₂ O ₃ , RhMn, NiMn, PdPtMn, or the like, in addition to PtMn.
[0056]
Preferably, the magnetization fixed layer 43 and the magnetization free layer 45 are made of NiFe or CoNiFe exhibiting excellent corrosion resistance and exhibiting good soft magnetic properties. More preferably, the magnetization fixed layer 43 and the magnetization free layer 45 are used. Both are preferably used in a combination of NiFe and CoNiFe.
Further, the magnetization fixed layer 43 and the magnetization free layer 45 may have a laminated structure in which these alloys are laminated, or a laminated ferri-structure in which these alloys and a nonmagnetic film made of, for example, Ru are alternately laminated.
[0057]
For the nonmagnetic layer 44, it is preferable to use Cu, CuAu, or Au that exhibits excellent corrosion resistance and high conductivity, and more preferably increases the MR ratio of the GMR element 27 to increase the output. It is preferable to use Cu or CuAu which can be used.
[0058]
Here, as the GMR element 27, for example, Ta as the lower layer 41, Ni ₈₀ Fe ₂₀ and Co ₅₀ Ni ₃₀ Fe _{20 as} the magnetization free layer 45, Cu ₇₀ Au _{30 as the} non-magnetic layer, and a magnetization fixed layer The structure includes a spin valve film 40 in which Ni ₈₀ Fe ₂₀ and Co ₅₀ Ni ₃₀ Fe ₂₀ to be 43, PtMn to be the antiferromagnetic layer 42, and Ta to be the protective layer 46 are sequentially laminated.
[0059]
In the spin valve film 40, the magnetization fixed layer 43 is disposed adjacent to the antiferromagnetic layer 42, so that an exchange coupling magnetic field acting between the magnetization fixed layer 43 and the antiferromagnetic layer 42 causes magnetization in a predetermined direction. It is in a fixed state.
On the other hand, the magnetization free layer 45 is magnetically isolated from the magnetization fixed layer 43 via the nonmagnetic layer 44, so that the magnetization direction can be easily changed with respect to a weak external magnetic field. .
[0060]
Therefore, when an external magnetic field is applied to the spin valve film 40, the magnetization direction of the magnetization free layer 45 changes according to the magnitude and direction of the external magnetic field. When the magnetization direction of the magnetization free layer 45 is opposite (antiparallel) to the magnetization direction of the magnetization fixed layer 43, the resistance value of the current flowing through the spin valve film 40 becomes maximum.
On the other hand, when the magnetization direction of the magnetization free layer 45 is in the same direction (parallel) as the magnetization direction of the magnetization fixed layer 43, the resistance value of the current flowing through the spin valve film 40 becomes minimum.
[0061]
As described above, the electric resistance of the spin valve film 40 changes in accordance with the applied external magnetic field. Therefore, the spin valve film 40 functions as a magnetic sensing element that detects the magnetic signal from the magnetic tape 3 by reading the change in resistance. I have.
[0062]
Further, in order to stabilize the operation of the GMR element 27, as shown in FIGS. 3 and 4, a bias magnetic field is applied to the GMR element 27 at both ends in the longitudinal direction of the spin valve film 40. A pair of permanent magnet films 28a and 28b are provided.
The width of the portion sandwiched between the pair of permanent magnet films 28a and 28b is the reproduction track width Tw of the GMR element 27.
Further, on the pair of permanent magnet films 28a and 28b, a pair of resistance reducing films 29a and 29b for reducing the resistance value of the GMR element 27 are provided.
[0063]
In the GMR element 27, a pair of conductors 30a and 30b for supplying a sense current to the spin valve film 28 are provided at one end thereof with a pair of permanent magnet films 28a and 28b and a resistance reducing film 29a, respectively. 29b.
A pair of external connection terminals 31a and 31b connected to an external circuit are provided on the other end side of the conductors 30a and 30b.
[0064]
The protective film 22 covers the main surface of the first core member 21 on which the GMR head 20 is formed, except for portions where the external connection terminals 31a and 31b face the outside. The first core member 21 and the second core member 23 are joined.
[0065]
The GMR head 20 shown in FIGS. 3 and 4 is enlarged around the GMR element 27 for easy understanding of the characteristics, but actually, the first core member 21 and the second core member 21 are not shown. The GMR element 27 is very fine as compared with the core member 23 of the first embodiment, and the GMR head 20 faces the outside on the medium sliding contact surface 20a because almost the first core member 21 and the second core member 23 Only the butted upper end face.
[0066]
The GMR head 20 configured as described above is attached to a chip base (not shown), and a pair of external connection terminals 31a and 31b are electrically connected to connection terminals provided on the chip base.
The GMR head 20 provided on the chip base is attached to the rotating drum 14 shown in FIG. 2 as a pair of reproducing heads 12a and 12b.
[0067]
By the way, in the recording / reproducing apparatus 1 for a magnetic tape described above, the reproducing operation is performed in a state where the GMR head 20 is in contact with the magnetic tape 3. A protective film such as a DLC (Diamond Like Carbon) film cannot be formed on 20a.
For this reason, the conventional recording / reproducing apparatus for a magnetic tape has a problem that the medium sliding surface of the GMR head comes into direct contact with the air, and the GMR element is likely to be corroded under high temperature and high humidity or in a seawater atmosphere. was there.
[0068]
In view of the above, in the GMR head 20 of the present invention, as shown in FIG. 3, a rust preventive film 50 containing an amine carboxylate compound is formed on the medium sliding contact surface 20a which is in sliding contact with the magnetic tape 3. did.
[0069]
The rust inhibitor film 50 can be formed by applying a rust inhibitor containing a carboxylic acid amine salt compound to the medium sliding surface 20 a of the GMR head 20. As the carboxylic acid amine salt compound, a compound having a structure shown in the following [Chemical Formula 1] is preferable.
[0070]
Embedded image

[0071]
However, in the above [Chemical formula 1], R ₁ , R ₂ and R ₃ represent hydrogen or a saturated or unsaturated fatty acid hydrocarbon group.
[0072]
The carboxylic acid amine salt compound preferably has a perfluoropolyether chain (PFPE) or a fluoroalkyl chain. Fluorine in a perfluoropolyether chain (PFPE) or a fluoroalkyl chain can impart water repellency, suppress adsorption of moisture, and improve corrosion resistance.
Fluorine also has the effect of improving the durability during running of the magnetic tape.
Furthermore, the amine compound and the carboxylic acid compound are effective in reducing friction, reduce friction during running of the magnetic tape, reduce the frictional force between the magnetic tape and the magnetic head, and improve running durability.
[0073]
Here, as the perfluoropolyether and the fluoroalkyl, any of commercially available ones can be applied. Preferably, the carboxylic acid amine salt compound is a compound represented by the following [Chemical Formula 2] or [Chemical Formula 3]. The average molecular weight of the above-mentioned perfluoropolyether chain or fluoroalkyl chain may be 300 to 8000. When the average molecular weight of the perfluoropolyether and fluoroalkyl is less than 300, the friction of the magnetic tape increases, which causes sticking to the drum when the magnetic tape runs. On the other hand, when the average molecular weight is larger than 8000, it becomes difficult to dissolve in an organic solvent, and further, because of aggregation, coating unevenness tends to occur when applied to a magnetic tape, making it impossible to apply uniformly.
When the carboxylic acid amine salt compound is applied, it may be applied by dissolving in an existing hydrocarbon solvent. Also, any known method can be applied to the coating method.
[0074]
Embedded image

[0075]
Embedded image

[0076]
However, in the above [Chemical Formula 2] and [Chemical Formula 3], Rf is a perfluoropolyether chain or a fluoroalkyl chain, and R ₁ , R ₂ and R ₃ are hydrogen or a saturated or unsaturated fatty acid hydrocarbon group. Is shown.
[0077]
The carboxylic acid amine salt compound has good reactivity with Cu and CuAu in the nonmagnetic layer 44 which affects the magnetoresistance ratio (MR ratio) of the spin valve film 40, and has a corrosion resistance to chlorine ions in a seawater atmosphere. It has the feature that it is excellent.
[0078]
Further, the thickness of the rust preventive film 50 is preferably in the range of 1 to 500 °.
If the thickness of the rust inhibitor film 50 is less than 1 mm, it is difficult to maintain the corrosion resistance. On the other hand, if the thickness of the rust inhibitor film 50 is greater than 500 mm, the GMR head 20 and the magnetic tape 3 are , And the output sensitivity of the GMR head 20 is reduced. Therefore, by setting the thickness of the rust preventive agent film 50 in the range of 1 to 500 °, it is possible to exhibit excellent corrosion resistance and maintain a high magnetoresistance ratio. Further, the thickness of the rust preventive film 50 is more preferably in the range of 2 to 200 °, and if the thickness of the rust preventive film 50 is defined in the range of 5 to 100 °, the GMR element 27 It is possible to prevent the occurrence of corrosion and the like and to obtain good short-wavelength recording / reproducing characteristics of the GMR element 27.
[0079]
Specifically, the rust preventive film 50 having good reactivity with CuAu of the nonmagnetic layer 44 constituting the above-described spin valve film 40 and having excellent corrosion resistance to chlorine ions in a seawater atmosphere is described below. When formed by applying the carboxylic acid amine salt compound shown in 4), the above-mentioned excellent effects were confirmed.
[0080]
Embedded image

[0081]
However, in the above [Chemical Formula 4], Rf in the above [Chemical Formula 2] is (CF ₂ CF ₂ O) _m (CF ₂ O) _n (molecular weight = 4000).
[0082]
As described above, in the GMR head 20 according to the present invention, even when a protective film such as a DLC film is not formed on the medium sliding contact surface 20a which is in sliding contact with the magnetic tape 3, the medium sliding contact surface 20a does not. The formed rust preventive film 50 can exhibit excellent corrosion resistance in the air, in a seawater atmosphere, and under high temperature and high humidity. Therefore, in the GMR head 20 of the present invention, it is possible to avoid the occurrence of corrosion or the like of the GMR element 27, and it is possible to perform an appropriate reproducing operation for the magnetic tape 3.
[0083]
Next, a magnetic recording medium applied to the magnetoresistive head according to the present invention will be described with reference to the drawings.
[0084]
The magnetic recording medium 60 shown in FIG. 6 is a so-called evaporation type magnetic tape in which a metal magnetic material film is obliquely evaporated on a non-magnetic support.
Magnetic tapes have excellent coercive force, remanent magnetization, squareness ratio, etc., and not only excellent electromagnetic conversion characteristics at short wavelengths, but also the thickness of the magnetic layer can be made extremely thin, resulting in recording demagnetization and thickness loss during reproduction. Since it is small and it is not necessary to mix a binder, which is a non-magnetic material, in the magnetic layer, it has many advantages such as increasing the packing density of the magnetic material and obtaining a large magnetization.
In the recording / reproducing apparatus 1 for a magnetic tape described above, by using such a magnetic recording medium 60 for the magnetic tape 3 of the tape cassette 2, it is possible to improve the electromagnetic conversion characteristics and obtain a larger output.
[0085]
Specifically, the magnetic recording medium 60 has a configuration in which a magnetic layer 62 made of a metal magnetic thin film and a protective layer 63 for protecting the magnetic layer 62 are sequentially laminated on a tape-shaped nonmagnetic support 61. have.
[0086]
Examples of the material of the nonmagnetic support 61 include polyesters such as polyethylene terephthalate and polyethylene-2,6-naphthalate, polyolefins such as polypropylene, cellulose derivatives such as cellulose triacetate and cellulose diacetate, polyamide, aramid resin, and polycarbonate. And the like.
The nonmagnetic support 61 may have a single-layer structure or a multilayer structure. Further, for example, the surface of the nonmagnetic support 61 may be subjected to a surface treatment such as a corona discharge treatment, or an organic material layer such as an easily adhesive layer may be formed as an undercoat layer.
[0087]
The magnetic layer 62 can be formed by applying a metal magnetic thin film using a conventionally known method such as a vacuum evaporation method, a sputtering method, a CVD (Chemical Vapor Deposition) method, an ion plating method, or the like. In particular, a film formed by a vacuum evaporation method is preferable.
The thickness of the metal magnetic thin film can be controlled by changing the line speed, and the amount of residual magnetization can be controlled by changing the amount of oxygen introduced during vapor deposition. A metal magnetic thin film having a thickness of about 50 nm can be reliably formed.
Further, the metal magnetic thin film of the magnetic layer 62 may be formed, for example, on a Cr underlayer. As the underlayer, CrTi, CrMo, CrV, or the like is used in addition to Cr. Further, the magnetic layer 62 may have a single-layer structure or a multilayer structure.
[0088]
In the magnetic recording medium 60, the product Mr · t of the residual magnetization amount Mr and the thickness t of the magnetic layer is preferably 4 mA to 17 mA, and more preferably 4 mA to 13 mA. If the Mr · t of the magnetic recording medium 60 is larger than 17 mA, the GMR head 20 will be saturated, the MR resistance change will be out of the linear region, and the reproduced waveform will be distorted, and the Mr · t will be larger than 4 mA. If the ratio is too small, a problem arises in that the reproduction output is small and a good SN ratio (signal / noise ratio) cannot be obtained. Therefore, by setting Mr · t in the range of 4 mA to 17 mA, the reproduced waveform is not distorted, the reproduced output is large, and the SN ratio is good.
[0089]
The above Mr and t can be adjusted by controlling the film formation conditions such as the amount of oxygen introduced during vapor deposition and the feed speed of the nonmagnetic support. That is, Mr can be increased by reducing the amount of oxygen introduced during the deposition, and can be decreased by increasing the amount of oxygen introduced.
Further, the film thickness t can be increased by reducing the feed speed of the nonmagnetic support 61 during the vapor deposition, and the film thickness t can be reduced by increasing the feed speed.
Also, Mr can be adjusted by a surface oxidation treatment after the formation of the magnetic layer 62.
[0090]
The residual magnetization Mr is preferably in the range of 160 kA / m to 360 kA / m. If Mr is larger than 360 kA / m, magnetic particles cannot be separated and noise increases due to magnetic interaction. If Mr is smaller than 160 kA / m, oxidation of Co particles proceeds, This is because a sufficient reproduction output cannot be obtained. Therefore, in order to reduce noise and provide a sufficient reproduction output, it is desirable to define Mr in the range of 160 kA / m to 360 kA / m, and more preferably, in the range of 200 kA / m to 340 kA / m. Is preferred.
[0091]
The surface electric resistance of the magnetic recording medium 60 is preferably in the range of 1 × 10 ³ Ω / sq to 1 × 10 ⁷ Ω / sq. If the surface electric resistance is larger than 1 × 10 ⁷ Ω / sq, a large charge is charged on the surface of the magnetic tape 3 while the magnetic tape 3 is running or the like, and when it comes into contact with the GMR head 20, a cause of ESD destruction (electrostatic destruction) is caused. When the surface electric resistance is smaller than 1 × 10 ³ Ω / sq, the electric charge easily flows on the medium surface, and when it comes into contact with the GMR head 20, a current suddenly flows through the head, causing ESD destruction. That's why. Therefore, by regulating the surface electric resistance in the range of 1 × 10 ³ Ω / sq to 1 × 10 ⁷ Ω / sq, the charging of the surface of the metal magnetic thin film or the flow of current is suppressed, and the static electricity of the GMR head 20 is reduced. Electric breakdown can be prevented.
[0092]
The thickness t of the metal magnetic thin film is preferably in the range of 15 nm to 50 nm. By defining t as described above, it is possible to adjust Mr.t, Mr, and surface electric resistance of the magnetic recording medium 60 to the above-described ranges, respectively.
[0093]
In the magnetic recording medium 60, the coercive force Hc in the in-plane direction is preferably in the range of 100 kA / m to 160 kA / m. If the coercive force is smaller than 100 kA / m, low noise and a high S / N ratio cannot be realized. If the coercive force exceeds 160 kA / m, sufficient recording cannot be performed and the reproduction output decreases. This is because Therefore, by defining the coercive force in the in-plane direction in the range of 100 kA / m to 160 kA / m, it is possible to realize a low noise and a high SN ratio, and a high reproduction output is obtained.
[0094]
As described above, in the magnetic recording medium 60, the product Mr · t of the residual magnetization Mr and the thickness t of the magnetic layer is in the range of 4 mA to 17 mA. The output is large and has a good SN ratio.
Further, in the magnetic recording medium 60, since Mr is set in the range of 160 kA / m to 360 kA / m, noise is reduced and a sufficient reproduction output is obtained.
Further, in the magnetic recording medium 60, the surface electric resistance of the metal magnetic thin film is set in the range of 1 × 10 ³ Ω / sq to 1 × 10 ⁷ Ω / sq, so that the surface of the metal magnetic thin film is charged or the electric current is reduced. Of the GMR head 20 can be prevented and the electrostatic breakdown of the GMR head 20 can be prevented. Therefore, in the magnetic recording medium 60 of the present invention, it is possible to reduce noise, to have a high reproduction output and a good S / N ratio, and to prevent saturation and electrostatic breakdown of the head when reproducing with the GMR head 20. Is possible.
[0095]
The protective layer 63 may be made of any material as long as it is used as a protective film for an ordinary metal magnetic thin film, for example, diamond-like carbon (DLC), CrO ₂ , Al ₂ O ₃ , BN, Co _{oxide, MgO, SiO 2, Si 3} O 4, SiN x, SiC, SiN x -SiO 2, ZrO 2, TiO 2, TiC , and the like. Further, these may be a single layer film, a multilayer film or a composite film.
The above-mentioned surface electric resistance can be adjusted by controlling the thickness of a diamond-like carbon (DLC) protective film formed on the metal magnetic thin film, for example.
[0096]
The magnetic recording medium 60 is made of the same material as the rust inhibitor film 50 formed on the medium sliding contact surface 20a of the GMR head 20 as a top coat layer 64 covering the main surface on the side where the magnetic layer 62 is formed. A rust inhibitor film may be formed.
[0097]
The rust preventive film forming the top coat layer 64 is mainly used for transferring the rust preventive film 50 to the medium sliding surface 20 a of the GMR head 20, in order to transfer the rust preventive film 50 to the GMR head 20 of the magnetic recording medium 60. It is formed on the surface with a predetermined thickness.
[0098]
Therefore, in the magnetic recording medium 60, the rust preventive film is transferred to the medium sliding contact surface 20a of the GMR head 20 by sliding the GMR head 20, and the transferred rust preventive film (in FIG. 3). By 50), the occurrence of corrosion or the like of the GMR element 27 is avoided.
[0099]
The magnetic recording medium 60 has a back coat layer 65 covering the main surface opposite to the main surface on which the magnetic layer 62 is formed. The back coat layer 65 is formed on the medium sliding contact surface 20a of the GMR head 20 described above. A rust inhibitor film made of the same material as the rust agent film is formed in a predetermined thickness.
[0100]
This back coat layer 65 transfers the rust preventive film to the top coat layer 64 facing the back coat layer 65 by being wound around the supply reel 4 shown in FIG. Therefore, the rust preventive film forming the back coat layer 65 is finally transferred to the medium sliding surface 20a of the GMR head 20 by sliding the GMR head 20 against the magnetic recording medium 60.
[0101]
The thickness of the rust preventive film constituting the top coat layer 64 and the back coat layer 65 is in the range of 1 to 500 ° similarly to the rust preventive film formed on the medium sliding contact surface 20a of the GMR head 20. Preferably, it is more preferably in the range of 2 to 200 °, more preferably in the range of 5 to 100 °.
[0102]
As described above, the magnetic recording medium 60 applied to the magnetoresistance effect type magnetic head of the present invention has a rust preventive film on the medium sliding contact surface 20a of the GMR head 20 when the GMR head 20 is in sliding contact. Since the transfer is performed directly or indirectly, even when the rust preventive film 50 is not formed on the medium sliding contact surface 20a of the GMR head 20, the transferred rust preventive film allows the GMR element 27 to be transferred. It is possible to avoid the occurrence of corrosion and the like.
Further, even when the rust preventive film 50 formed on the medium sliding contact surface 20a of the GMR head 20 is reduced due to abrasion, the rust preventive film is directly or indirectly transferred from the magnetic recording medium 60 to prevent the rust preventive film. The rust agent film 50 can be maintained at a desired film thickness. Therefore, it is particularly suitable as the magnetic tape 3 of the tape cassette 2 loaded in the recording / reproducing apparatus 1 for magnetic tape.
[0103]
Note that the magnetic recording medium 60 is not limited to the above-described configuration, and may have a configuration in which the protective layer 63 is not formed on the magnetic layer 62 as necessary. In this case, the rust preventive film (top coat layer 64) is directly coated on the magnetic layer 62, and the rust preventive film can prevent the magnetic layer 62 from being oxidized or corroded.
Further, the magnetic recording medium 60 is not limited to the configuration in which the rust preventive film is formed on both surfaces thereof, and the magnetic recording medium 60 may have the rust preventive film formed only on the main surface on which the magnetic layer 62 is formed. The rust preventive film may be formed only on the main surface on the side opposite to the main surface on which is formed.
[0104]
As described above, in the recording / reproducing apparatus 1 for a magnetic tape, an unprecedented high-density recording / reproducing system can be constructed by combining the GMR head 20 of the present invention and the magnetic recording medium 60. . In the recording / reproducing apparatus 1 for a magnetic tape, even when the magnetic signal is detected while the GMR head 20 slides against the magnetic recording medium 60 by the helical scan method, the medium sliding contact surface of the GMR head 20 can be used. 20a can be prevented from being corroded.
[0105]
【Example】
Next, specific examples of the present invention will be described.
First, a GMR head having the rust preventive film formed on the medium sliding contact surface and a GMR head having no rust preventive film formed on the medium sliding contact surface were manufactured, and a recording / reproducing apparatus for a magnetic tape was manufactured. The GMR head was left standing without running the magnetic tape using the same, and the corrosion resistance of the head was examined.
[0106]
Here, as a first magnetic head, a Ta film serving as a base layer, a NiFe film and a CoNiFe film serving as a magnetization free layer, a Cu film serving as a non-magnetic layer, and a NiFe film serving as a magnetization fixed layer are formed as a first magnetic head. A GMR head including a spin valve film in which a PtMn film serving as a ferromagnetic layer and a Ta film serving as a protective layer are sequentially laminated is manufactured. As a second magnetic head, a Ta film serving as an underlayer and a magnetization free layer are formed. A NiFe film and a CoNiFe film as layers, a CuAu film as a nonmagnetic layer, a NiFe film as a magnetization fixed layer, a PtMn film as an antiferromagnetic layer, and a Ta film as a protective layer are sequentially stacked. A GMR head having a spin valve film was manufactured.
[0107]
Regarding the first and second magnetic heads, the case where the rust preventive film was not formed on the medium sliding contact surface and the case where the rust preventive film composed of a carboxylic acid amine salt compound was formed on the medium sliding contact surface were as follows. Each was evaluated for the occurrence of corrosion by a salt water test.
[0108]
The evaluation results are shown in Table 1 below. In Table 2, ◎ indicates that no corrosion occurred and excellent corrosion resistance was confirmed in the main corrosion test, ○ indicates that no corrosion was observed in the main corrosion test, and x indicates And the case where the occurrence of corrosion was confirmed in the present corrosion test.
[0109]
[Table 1]

[0110]
From the evaluation results shown in Table 1 above, in each of the first magnetic head and the second magnetic head, corrosion occurred when no rust preventive film was formed.
On the other hand, when a rust preventive film was formed on the sliding surface of the medium, no corrosion occurred, and excellent corrosion resistance was exhibited.
[0111]
Next, a GMR head having a rust preventive film formed on the medium sliding contact surface and a GMR head having no rust preventive film formed on the medium sliding contact surface were prepared, and the rust preventive film was formed on the surface. A magnetic tape and a magnetic tape having no rust preventive film formed on the surface thereof were prepared, and in a recording / reproducing apparatus for the magnetic tape, the GMR head was slidably contacted with the magnetic tape and traveled for 5 passes. The presence or absence of occurrence was evaluated.
[0112]
The first magnetic head described above was used as the magnetic head, the carboxylic acid amine salt compound 1 shown in Table 1 was used as the rust preventive film, and the magnetic tape was the side on which the magnetic layer was formed. Only the main surface was used in which a rust preventive film was formed by coating.
[0113]
The evaluation results are shown in Table 2 below. In Table 2, ◎ indicates a case where no corrosion occurred and excellent corrosion resistance was confirmed in the present corrosion test, ○ indicates a case where no corrosion was observed in the present corrosion test, and × Indicates the case where occurrence of corrosion was confirmed in the present corrosion test.
[0114]
[Table 2]

[0115]
As shown in Table 2, when a GMR head having no rust preventive film formed on the medium sliding contact surface was brought into sliding contact with a magnetic tape having no rust preventive film formed on the surface, corrosion occurred. You can see that
On the other hand, when the GMR head having the rust preventive film formed on the medium sliding surface is brought into sliding contact with a magnetic tape having no rust preventive film formed on the surface, When the GMR head, which was not formed on the contact surface, was brought into sliding contact with the magnetic tape having the rust preventive film formed on the surface, no corrosion occurred. In particular, the rust preventive film was formed on the medium sliding contact surface. It can be seen that when the GMR head thus formed is brought into sliding contact with a magnetic tape having a rust preventive film formed on its surface, excellent corrosion resistance is exhibited.
[0116]
Next, a magnetic tape having no rust preventive film formed on its surface, a magnetic tape having a rust preventive film formed only on the main surface on which the magnetic layer was formed, and a magnetic tape having only the main surface on which the magnetic layer was formed. A magnetic tape with a rust inhibitor film formed only on the opposite main surface and a magnetic tape with a rust inhibitor film formed on both sides were prepared. An evaluation was made as to whether or not corrosion had occurred when a GMR head that had not been formed was slid into contact with it and allowed to travel for five passes.
[0117]
The first magnetic head described above was used as a magnetic head, and the carboxylic acid amine salt compound 5 shown in Table 1 was used as a rust preventive film.
[0118]
The evaluation results are shown in Table 3 below. In Table 3, ◎ indicates the case where no corrosion occurred and excellent corrosion resistance was confirmed in the present corrosion test, ○ indicates the case where no corrosion was observed in the present corrosion test, and × Indicates the case where occurrence of corrosion was confirmed in the present corrosion test.
[0119]
[Table 3]

[0120]
As shown in Table 3 above, it can be seen that corrosion occurs when the GMR head is brought into sliding contact with the magnetic tape having no rust preventive film formed on the surface.
On the other hand, when the GMR head is brought into sliding contact with the magnetic tape on which only the main surface on which the magnetic layer is formed, the anticorrosive film is formed, and on the side opposite to the main surface on which the magnetic layer is formed. When the GMR head is slid on the magnetic tape having only the main surface of the rust preventive film, no corrosion occurs. In particular, the GMR head slides on the magnetic tape on which the rust preventive film is formed on both surfaces. It can be seen that when this is done, excellent corrosion resistance is exhibited.
[0121]
Next, a magnetic tape having no rust inhibitor film formed on the main surface on which the magnetic layer was formed, and a magnetic tape having a rust preventive film formed on the main surface on which the magnetic layer was formed, These magnetic tapes were manufactured and evaluated for the occurrence of corrosion after an atmospheric test for one week in a 60 ° C. × 90% RH atmosphere.
[0122]
Here, the residual magnetization amount Mr of the manufactured magnetic tape is 285 mA / m, the thickness t of the metal magnetic thin film is 40 nm, the product Mr · t thereof is 12 mA, and the coercive force Hc is , And 120 kA / m.
Further, as the rust preventive film, the carboxylic acid amine salt compounds 1 and 5 shown in Table 1 above were applied.
[0123]
The evaluation results are shown in Table 4 below. In Table 4, ○ indicates the case where the occurrence of corrosion was not confirmed in the present corrosion test, and × indicates the case where the occurrence of corrosion was confirmed in the present corrosion test.
[0124]
[Table 4]

[0125]
From the evaluation results in Table 4, it can be seen that corrosion occurs in the magnetic tape in which the rust preventive film was not formed on the main surface on the side where the magnetic layer was formed.
On the other hand, it can be seen that the magnetic tape having the rust preventive film formed on the main surface on the side where the magnetic layer is formed has no corrosion and exhibits excellent corrosion resistance.
[0126]
【The invention's effect】
According to the magnetoresistive effect type magnetic head of the present invention, the rust preventive film containing the amine carboxylate compound is formed on the medium sliding contact surface of the magnetoresistive effect element. Corrosion or the like can be prevented from occurring on the contact surface, and it is possible to perform an appropriate reproducing operation on the magnetic recording medium.
[0127]
Further, according to the recording / reproducing apparatus according to the present invention, the rust preventive film containing the amine carboxylate compound is brought into contact with the medium sliding surface of the magnetoresistive element by the slidable contact of the magnetoresistive magnetic head with the magnetic tape. The surface of the sliding surface of the medium is covered with a rust-preventive agent film transferred from the magnetic recording medium. It became. Therefore, by combining the magneto-resistance effect type magnetic head and the magnetic tape, it is possible to further increase the recording density of the magnetic tape while preventing corrosion and the like of the magneto-resistance effect type magnetic head.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a recording / reproducing apparatus for a magnetic tape.
FIG. 2 is a schematic perspective view of a head drum constituting the recording / reproducing apparatus.
FIG. 3 is a schematic perspective view of a magnetoresistive head according to the present invention.
FIG. 4 is an end view of the GMR head as viewed from a surface in contact with the medium.
FIG. 5A is a schematic cross-sectional view of a bottom type spin valve film.
(B) A schematic sectional view of a top type spin valve film is shown.
(C) A schematic sectional view of a dual type spin valve film is shown.
FIG. 6 is a schematic sectional view of a magnetic recording medium applied to the recording / reproducing apparatus of the present invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Magnetic tape device, 2 ... Tape cassette, 3 ... Magnetic tape, 4 ... Supply reel, 5 ... Take-up reel, 6 ... Device main body, 7a-7f ... Guide roller, 8 ... Pinch Roller, 9 Capstan, 10 Capstan motor, 11a, 11b Magnetic head for recording, 12a, 12b Magnetic head for reproduction, 13 Head drum, 14 Rotary drum, 15 Fixed drum, 16 Drive motor, 20 Magnetic resistance effect type magnetic head, 20a Medium sliding contact surface, 21 First core member, 22 Protective film, 23 Second core member , 24, 25 ... shield layer, 26 ... gap layer, 27 ... GMR element, 28a, 28b ... permanent magnet film, 29a, 29b ... low resistance film, 30a, 30b ... conductor part, 31a, 31b …… for external connection Terminal, 40: Spin valve film, 41: Underlayer, 42: Antiferromagnetic layer, 43: Fixed magnetization layer, 44: Nonmagnetic layer, 45: Free magnetization layer, 50: Rust inhibitor Film 60, magnetic recording medium 61 Non-magnetic support 62 Magnetic layer 63 Protective layer 64 Top coat layer 65 Back coat layer

Claims (4)

A magneto-resistance effect type magnetic head including a magneto-resistance effect element as a magneto-sensitive element that detects a magnetic signal while sliding on a magnetic recording medium,
A magnetoresistance effect type magnetic head, wherein a rust preventive film containing a carboxylic acid amine salt compound is formed on a surface of the magnetoresistance effect element that is in sliding contact with the magnetic recording medium. 2. The magnetoresistive head according to claim 1, wherein the magnetic head is mounted on a rotating drum and detects a magnetic signal while sliding on a tape-shaped magnetic recording medium by a helical scan method. A magnetoresistive effect type having a magnetic tape, a tape running means for running the magnetic tape, and a magnetoresistive element as a magnetic sensing element for detecting a magnetic signal while slidingly contacting the magnetic tape run by the tape running means. A recording / reproducing apparatus comprising a magnetic head,
A rust preventive agent film containing a carboxylic acid amine salt compound is formed on the main surface of the magnetic tape on the side where the magnetoresistive magnetic head is slid and / or on the main surface opposite to the main surface. Has been
A recording / reproducing apparatus, wherein the rust preventive agent film is transferred to a medium sliding contact surface of the magnetoresistive effect element by slidingly contacting the magnetoresistive magnetic head with the magnetic tape. 4. The recording / reproducing apparatus according to claim 3, wherein the magnetoresistive head is mounted on a rotating drum and detects a magnetic signal while slidingly contacting the magnetic tape by a helical scan method.

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