JPH0263256B2 - - Google Patents
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- Publication number
- JPH0263256B2 JPH0263256B2 JP19338283A JP19338283A JPH0263256B2 JP H0263256 B2 JPH0263256 B2 JP H0263256B2 JP 19338283 A JP19338283 A JP 19338283A JP 19338283 A JP19338283 A JP 19338283A JP H0263256 B2 JPH0263256 B2 JP H0263256B2
- Authority
- JP
- Japan
- Prior art keywords
- film
- temperature
- magnetic recording
- expansion coefficient
- humidity
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 230000005291 magnetic effect Effects 0.000 claims description 67
- 239000010408 film Substances 0.000 claims description 47
- 239000010409 thin film Substances 0.000 claims description 25
- 229910052751 metal Inorganic materials 0.000 claims description 24
- 239000002184 metal Substances 0.000 claims description 24
- -1 poly-1,4-cyclohexylene dimethylene terephthalate Chemical compound 0.000 claims description 17
- 239000000463 material Substances 0.000 claims description 10
- 229920006267 polyester film Polymers 0.000 claims description 6
- 238000000034 method Methods 0.000 description 28
- KKEYFWRCBNTPAC-UHFFFAOYSA-N Terephthalic acid Chemical compound OC(=O)C1=CC=C(C(O)=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-N 0.000 description 16
- 239000010410 layer Substances 0.000 description 15
- 238000004544 sputter deposition Methods 0.000 description 13
- 229920000728 polyester Polymers 0.000 description 12
- 229910045601 alloy Inorganic materials 0.000 description 10
- 239000000956 alloy Substances 0.000 description 10
- QQVIHTHCMHWDBS-UHFFFAOYSA-N isophthalic acid Chemical compound OC(=O)C1=CC=CC(C(O)=O)=C1 QQVIHTHCMHWDBS-UHFFFAOYSA-N 0.000 description 8
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 7
- 239000012298 atmosphere Substances 0.000 description 7
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 6
- YIMQCDZDWXUDCA-UHFFFAOYSA-N [4-(hydroxymethyl)cyclohexyl]methanol Chemical class OCC1CCC(CO)CC1 YIMQCDZDWXUDCA-UHFFFAOYSA-N 0.000 description 6
- 239000002253 acid Substances 0.000 description 5
- 230000005415 magnetization Effects 0.000 description 5
- 238000005259 measurement Methods 0.000 description 5
- 229920000139 polyethylene terephthalate Polymers 0.000 description 5
- 239000005020 polyethylene terephthalate Substances 0.000 description 5
- 238000012360 testing method Methods 0.000 description 5
- 238000007740 vapor deposition Methods 0.000 description 5
- 230000008859 change Effects 0.000 description 4
- 238000005229 chemical vapour deposition Methods 0.000 description 4
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 4
- 229910000684 Cobalt-chrome Inorganic materials 0.000 description 3
- MUBZPKHOEPUJKR-UHFFFAOYSA-N Oxalic acid Chemical compound OC(=O)C(O)=O MUBZPKHOEPUJKR-UHFFFAOYSA-N 0.000 description 3
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 3
- 239000010952 cobalt-chrome Substances 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 238000010438 heat treatment Methods 0.000 description 3
- 238000007733 ion plating Methods 0.000 description 3
- 238000001771 vacuum deposition Methods 0.000 description 3
- DYLIWHYUXAJDOJ-OWOJBTEDSA-N (e)-4-(6-aminopurin-9-yl)but-2-en-1-ol Chemical compound NC1=NC=NC2=C1N=CN2C\C=C\CO DYLIWHYUXAJDOJ-OWOJBTEDSA-N 0.000 description 2
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 2
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 2
- 229910000599 Cr alloy Inorganic materials 0.000 description 2
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- WNLRTRBMVRJNCN-UHFFFAOYSA-N adipic acid Chemical compound OC(=O)CCCCC(O)=O WNLRTRBMVRJNCN-UHFFFAOYSA-N 0.000 description 2
- 230000008901 benefit Effects 0.000 description 2
- 238000000151 deposition Methods 0.000 description 2
- 230000008021 deposition Effects 0.000 description 2
- WOZVHXUHUFLZGK-UHFFFAOYSA-N dimethyl terephthalate Chemical compound COC(=O)C1=CC=C(C(=O)OC)C=C1 WOZVHXUHUFLZGK-UHFFFAOYSA-N 0.000 description 2
- 238000007772 electroless plating Methods 0.000 description 2
- 238000010894 electron beam technology Methods 0.000 description 2
- 230000004907 flux Effects 0.000 description 2
- 230000006872 improvement Effects 0.000 description 2
- 239000011261 inert gas Substances 0.000 description 2
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 2
- 238000000691 measurement method Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000035699 permeability Effects 0.000 description 2
- XNGIFLGASWRNHJ-UHFFFAOYSA-N phthalic acid Chemical compound OC(=O)C1=CC=CC=C1C(O)=O XNGIFLGASWRNHJ-UHFFFAOYSA-N 0.000 description 2
- CXMXRPHRNRROMY-UHFFFAOYSA-N sebacic acid Chemical compound OC(=O)CCCCCCCCC(O)=O CXMXRPHRNRROMY-UHFFFAOYSA-N 0.000 description 2
- 230000000930 thermomechanical effect Effects 0.000 description 2
- 238000007738 vacuum evaporation Methods 0.000 description 2
- 239000005995 Aluminium silicate Substances 0.000 description 1
- KDYFGRWQOYBRFD-UHFFFAOYSA-N Succinic acid Natural products OC(=O)CCC(O)=O KDYFGRWQOYBRFD-UHFFFAOYSA-N 0.000 description 1
- 150000007513 acids Chemical class 0.000 description 1
- 239000012790 adhesive layer Substances 0.000 description 1
- 239000001361 adipic acid Substances 0.000 description 1
- 235000011037 adipic acid Nutrition 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- 229910052786 argon Inorganic materials 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- KDYFGRWQOYBRFD-NUQCWPJISA-N butanedioic acid Chemical compound O[14C](=O)CC[14C](O)=O KDYFGRWQOYBRFD-NUQCWPJISA-N 0.000 description 1
- 229910000019 calcium carbonate Inorganic materials 0.000 description 1
- 235000010216 calcium carbonate Nutrition 0.000 description 1
- 239000001506 calcium phosphate Substances 0.000 description 1
- 229910000389 calcium phosphate Inorganic materials 0.000 description 1
- 235000011010 calcium phosphates Nutrition 0.000 description 1
- 238000005266 casting Methods 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000010531 catalytic reduction reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- 238000001514 detection method Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 238000011156 evaluation Methods 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 230000005294 ferromagnetic effect Effects 0.000 description 1
- 239000007789 gas Substances 0.000 description 1
- 230000009477 glass transition Effects 0.000 description 1
- 125000003827 glycol group Chemical group 0.000 description 1
- 238000009998 heat setting Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910052742 iron Inorganic materials 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 238000003475 lamination Methods 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000001755 magnetron sputter deposition Methods 0.000 description 1
- 230000007246 mechanism Effects 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 235000006408 oxalic acid Nutrition 0.000 description 1
- 229910000889 permalloy Inorganic materials 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000011241 protective layer Substances 0.000 description 1
- 238000011160 research Methods 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000003381 stabilizer Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 229910000815 supermalloy Inorganic materials 0.000 description 1
- ISIJQEHRDSCQIU-UHFFFAOYSA-N tert-butyl 2,7-diazaspiro[4.5]decane-7-carboxylate Chemical compound C1N(C(=O)OC(C)(C)C)CCCC11CNCC1 ISIJQEHRDSCQIU-UHFFFAOYSA-N 0.000 description 1
- 229920001169 thermoplastic Polymers 0.000 description 1
- 239000004416 thermosoftening plastic Substances 0.000 description 1
- 239000004408 titanium dioxide Substances 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- QORWJWZARLRLPR-UHFFFAOYSA-H tricalcium bis(phosphate) Chemical compound [Ca+2].[Ca+2].[Ca+2].[O-]P([O-])([O-])=O.[O-]P([O-])([O-])=O QORWJWZARLRLPR-UHFFFAOYSA-H 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 229910000859 α-Fe Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/74—Record carriers characterised by the form, e.g. sheet shaped to wrap around a drum
- G11B5/82—Disk carriers
- G11B5/825—Disk carriers flexible discs
Landscapes
- Compositions Of Macromolecular Compounds (AREA)
- Magnetic Record Carriers (AREA)
Description
技術分野
この発明はトラツキングミスを回避できる金属
薄膜からなる磁気記録層を設けた磁気記録フレキ
シブルデイスクに関する。更に詳しくは、高いト
ラツク密度記録の可能な金属薄膜からなる磁気記
録層を設けた磁気記録フレキシブルデイスクに係
る。
従来技術
一般式、磁気フレキシブルデイスク記録再生装
置自体に、温度変化を抑制する機構やトラツク検
出の特別な回路（トラツクサーボ等）を設けるこ
とによつて、トラツキングミスを防止することが
従来から知られている。もつとも、これらの手段
では記録再生装置が複雑となるので汎用的ではな
い。実際的には、基材フイルムや磁気材料に可能
な限り、熱膨張率及び湿度膨張率の小さい材料を
選択することによつて、磁気フレキシブルデイス
クを造り、トラツキングミスを防止する手段が採
られている。
しかしながら、この様な磁気フレキシブルデイ
スクでも高温（40〜50℃）及び／又は高湿（約80
％RH）で使用すると、トラツキングミスが発生
する。特に、低温（10℃程度）ないし低湿（20％
RH程度）の条件下で記録した磁気フレキシブル
デイスクは、常温（25℃程度）及び通常の湿度
（60％RH程度）雰囲気のもとで再生するとトラ
ツキングミスが発生するという欠点があつた。こ
のトラツキングミスによつて、出力エンベロープ
の低下が起り、Ｓ／Ｎ比が悪くなるという問題は
未解決である。
近年特に、高密度磁気記録媒体としてバインダ
ーを用いず、磁気記録層として金属薄膜を真空蒸
着やスパツタリングの如き真空沈着法によつて非
磁性支持体である熱可塑性プラスチツク上に形成
して、この金属薄膜を磁気記録材とするものと
か、無電解メツキ法により金属薄膜体を得る方法
等が数多く提案されている。
これら金属薄膜からなる磁気記録層を設けてな
る磁気フレキシブルデイスクについては、多くの
場合、磁気記録媒体の膜厚方向の磁化によつて記
録を行なう、いわゆる垂直磁気記録に関するもの
であるが、これらの改良だけでは磁気記録の高密
度化には不充分であり、前記基材フイルムの温
度、湿度膨張率に寄因するトラツク密度の向上も
同時に満足することによつて高密度磁気記録が達
成されるものである。
この様な高いトラツク密度記録の可能な金属薄
膜よりなる磁気記録フレキシブルデイスクは未だ
得られていない。
発明の目的
本発明者は上記の欠点を解消するため研究を重
ねた結果、ポリ−１，４−シクロヘキシレンジメ
チレンテレフタレート系ポリエステルよりなる２
軸配向フイルムの温度及び湿度膨張率を特定範囲
に調整することによつて、寸法安定性の高いフイ
ルムを得、これを基材として金属薄膜よりなる磁
気記録フレキシブルデイスクを造ることによつ
て、トラツキングミスの発生を回避できることを
見出し本発明に到達した。
本発の目的は、使用可能な雰囲気条件温度、湿
度範囲を拡大し、高温、高湿の条件でもトラツキ
ングミスが発生しない様に改良した金属薄膜より
なる磁気記録フレキシブルデイスクを提供するこ
とにある。
更に、この様な温度、湿度による寸法安定性の
高い金属薄膜よりなる磁気記録フレキシブルデイ
スクは、磁気記録の高密度化、就中、トラツク密
度の向上を可能にするものであつて、かようなデ
イスクを提供することも本発明の他の目的であ
る。
発明の構成
本発明は、酸成分の80モル％以上がテレフタル
酸より構成されたポリ−１，４−シクロヘキシレ
ンジメチレンテレフタレート系ポリエステルから
なる２軸配向フイルムを基材とし、該フイルムの
長手方向及び巾方向を含む面における最大の温度
膨張率が９〜35×10-6℃-1、最大の湿度膨張率が
０〜8.0×10-6℃（％RH）-1、最大と最小との温
度膨張率の差が０〜8.0×10-6℃-1、かつ最大と
最小と湿度膨張率の差が０〜3.0×10-6（％RH）-1
であるものに金属薄膜からなる磁気記録層を設け
てなる磁気記録フレキシブルデイスクである。
この磁気記録フレキシブルデイスクは、前記、
ポリ−１，４−シクロヘキシレンジメチレンテレ
フタレート系ポリエステル２軸配向フイルム上に
真空蒸着、スパツタ、イオンプレーテイング、C.
V.D.（Chemical Vapour Deposition），又は、無
電解メツキ等の方法を用いることによつて得られ
る。
また、ポリ−１，４−シクロヘキシレンジメチ
レンテレフタレート系ポリエステル２軸配向フイ
ルムは上記の温度、湿度膨張率の条件を満足する
ように、製膜条件を適宜にコントロールすること
によつて製造することができる。
本発明の磁気記録フレキシブルデイスクは、金
属薄膜からなる磁性層と基材フイルムとによつて
構成されている。この様な金属薄膜形成の手段
は、前述の様に真空蒸着法、スパツタ法、イオン
プレーテイング法、C.V.D.（Chemical Vapour
Deposition）法、無電解メツキ法等の方法を挙げ
ることができるが、これらの金属薄膜の形成法と
しては従来公知のすべての方法を用いることがで
きる。
真空蒸着法の場合には、10-4〜10-6Torrの真
空下でタングステンボートやアルミナハース中の
蒸着金属を抵抗加熱、高周波加熱、電子ビーム加
熱等により蒸発させ、上記支持体上に沈着せしめ
る。蒸着金属としてはFe，Ni，Co及びそれらの
合金が通常用いられる。また、本発明にはO2雰
囲気中でFeを蒸発させ酸化鉄薄膜を得る反応蒸
着法も適用できる。イオンプレーテイング法で
は、10-4〜10-3Torrの不活性ガスを主成分とす
る雰囲気中で、DCグロー放電、RFグロー放電を
起し、放電中で金属を蒸発さす。不活性ガスとし
ては通常Arが用いられる。スパツタ法では10-3
〜10-1TorrのArを主成分とする雰囲気中でグロ
ー放電を起し、生じたArイオンでターゲツト表
面の原子をたたき出す。グロー放電を起す方法と
して直流２極、３極スパツタ法及び高周波スパツ
タ法がある。又、マグネトロン放電を利用したマ
グネトロンスパツタ法もある。
磁気薄膜の厚さは高密度磁気記録媒体として充
分な信号出力を提供するものでなければならな
い。従つて、磁気薄膜の厚さは薄膜形成法、用途
によつて異なるが、一般に0.02〜1.5μm（200〜
15000Å）の間にある。
長手記録用磁気薄膜の形成法としては、蒸着
（熱蒸着、電子ビーム蒸着等）、スパツタリング
（２極直流スパツタリング、高周波スパツタリン
グ等）等の方法が挙げられる。蒸着の場合磁化容
易軸をテープ水平方向に発現するようCo等の強
磁性体金属を非磁性のプラスチツク支持体に対し
連続的に斜方蒸着を行ない、繰り返し積層するこ
とによつて、結晶磁気異方性、形状異方性をテー
プ水平方向に発現させるものである。従つてトー
タルとしての金属薄膜厚さは、0.02〜0.5μm（200
〜5000Å）程度である。
また、上述の如き長手記録用磁気薄膜の形成法
の他に、高密度デジタル記録が可能な方法として
フレキシブルデイスク用に、磁化容易軸を非磁性
支持体の垂直方向に発現するよう、例えばCoに
Crを適当量混入（10〜20％）して、発生する減
磁界を抑えて垂直方向に磁化容易軸を発現させ、
基盤面に対し垂直方向に記録を行なう垂直磁気記
録法も適用できる。
通常スパツタ法では、0.2〜1.5μm厚みのCo〜
Cr合金が用いられる。この時非磁性支持体と、
垂直方向に磁化容易軸を有する磁気記録層の間に
パーマロイ（Fe−Ni）、スーパーマロイ等の高透
磁率材料からなる磁束集束体薄膜を配することが
できる。磁束集束体としての高透磁率材料はスパ
ツタリングによつて形成され、膜厚は0.1〜1μm
（1000〜10000Å）の低保磁力（50Oe以下）薄膜
層である。このときの磁気記録層のCo−Cr膜厚
は、0.2〜1.5μm（2000〜15000Å）程度に形成す
る。
なお、金属薄膜よりなる磁気記録層は基材フイ
ルムの表裏に少なくとも一層の磁気記録層があれ
ば良いが、特公昭58−91号公報に開示のごとく、
NiFe合金薄膜等の軟磁性層を有していても良く、
また基材フイルムと金属薄膜との間に適当な接着
剤層があつても良く、金属薄膜上に保護層を有し
ていても良い。
本発明における基材フイルムであるポリ−１，
４−シクロヘキシレンジメチレンテレフタレート
系ポリエステルとしては、二塩基酸成分のうち80
モル％以上がテレフタル酸より成り、グリコール
成分は１，４−シクロヘキサンジメタノールのシ
スまたはトランス異性体より選ばれたグリコール
である。テレフタル酸以外の二塩基酸成分として
は、イソフタル酸、フタル酸、アジピン酸、セバ
チン酸、コハク酸、シユウ酸等の二塩基酸が例示
される。好ましくは、イソフタル酸である。
本発明において用いる１，４−シクロヘキサン
ジメタノールは、ジメチルテレフタレートまたは
テレフタル酸の接触還元によつて製造されるが、
いずれの方法で製造されたものでも支障がない。
１，４−シクロヘキサンジメタノールのシス体
とトランス体との比は特に制限するものではない
が、シス体／トランス体＝４／６〜０／10の範囲
のものが好ましい。
前記ポリ−１，４−シクロヘキシレンジメチレ
ンテレフタレート系ポリエステル中には、例え
ば、リン酸、亜リン酸及びそれらのエステル等の
安定剤、二酸化チタン、微粒子状シリカ、カオリ
ン、炭酸カルシウム、リン酸カルシウム等の艷消
剤、滑剤等が含まれていても良い。
本発明で用いられるポリ−１，４−シクロヘキ
シレンジメチレンテレフタレート系ポリエステル
２軸配向フイルムは、フイルムの長手方向及び巾
方向を含む面における最大の温度膨張率が９〜35
×10-6℃-1、好ましくは９〜25×10-6℃-1、最大
の湿度膨張率が０〜8.0×10-6（％RH）-1、好まし
くは０〜5.0×10-6（％RH）-1であり、しかも最大
と最小との温度膨張率の差が０〜8.0×10-6℃-1、
好ましくは０〜5.0×10-6℃-1また最大と最小と
の湿度膨張率の差が０〜3.0×10-6（％RH）-1、好
ましくは０〜2.5×10-6（％RH）-1である。フイル
ム基材の温度、湿度膨張率がこの範囲を満足する
と、フレキシブルデイスクのトラツキングミスは
防止でき、広い温度、湿度範囲での使用が可能に
なる。温度又は湿度膨張率が上記に規定した範囲
を超えると、磁気記録フレキシブルデイスクに記
録した雰囲気と異なつた温度で再生した場合に、
温度膨張率、湿度膨張率の差によつて磁気フレキ
シブルデイスクの中心から伸びが異なり磁気ヘツ
ドと記録トラツクがずれてトラツキングミスを発
生する原因となる。この結果、出力が変化して、
ドロツプアウトを生ずる。
現状技術では、磁気記録フレキシブルデイスク
として最も一般的に用いられているポリエチレン
テレフタレート系ポリエステルフイルムでは、最
大の温度膨張率は約17×10-6℃-1、温度膨張率の
最大と最小の差は８×10-6℃-1程度で、温度膨張
率の面では記録再生装置の温度膨張率とほぼ一致
するものの、面内方向における温度膨張率差によ
るトラツクずれを完全に防止することはできな
い。また湿度張率については約11×10-6（％
RH）-1程度とかなり大きく湿度変化に対応した
トラツクずれは、記録再生装置の湿度膨率が０と
みなせるのでかなり大きなものとなる。一方、本
発明のポリ−１，４−シクロヘキシレンジメチレ
ンテレフタレート系ポリエステル２軸配向フイル
ムを用いることによつて、一般的に用いられてい
るポリエチレンテレフタレート系ポリエステルよ
りなる２軸配向フイルムよりも温度膨張及び湿度
膨張に伴うトラツクずれが小さく、かつ温度膨張
率の最大値と最小値との差、湿度膨張率の最大値
と最小値との差を小さくすることによつて、トラ
ツクずれを更に小さく抑えることができ、広い温
度、湿度範囲の雰囲気での使用に全く支障がな
い。しかもこの基材フイルムは磁気記録が高密度
化された磁気記録フレキシブルデイスクが得られ
る。
上記の膨張特性を得るためのポリ−１，４−シ
クロヘキシレンジメチレンテレフタレート系ポリ
エステルフイルムの製膜方法は、ポリエチレンテ
レフタレート等の通常のポリエステルフイルムの
製膜法と同様な製造法が適用できる。例えば、Ｔ
−ダイ法、インフレーシヨン法等によつて溶融押
出された未延伸フイルムを造ることができる。更
に、２軸方向に延伸して２軸配向フイルムとなし
得る。この時の延伸温度は、ポリエチレンテレフ
タレートフイルムの場合とほぼ同様の条件で実態
できるが、ポリ−１，４−シクロヘキシレンジメ
チレンテレフタレート系ポリエステル中のテレフ
タル酸含有量によりガラス転移温度、融点が変化
するので、これに対応して溶融温度やキヤステイ
ングドラムの温度を適宜選択する必要がある。延
伸温度としては通常80〜140℃であり、また延伸
倍率としては縦方向に3.0〜5.0倍、好ましくは3.5
〜4.5倍、横方向に3.0〜5.0倍、好ましくは3.5〜
4.5倍程度を選択する。得られた２軸配向フイル
ムを150〜260℃（好ましくは180〜250℃）で１〜
100秒熱固定することによつて、本発明の温度、
湿度膨張によるトラツクずれの小さいフイルムが
得られる。しかし、本発明のポリ−１，４−シク
ロヘキシレンジメチレンテレフタレート系ポエス
テルよりなる２軸配向フイルムは、この様な方法
で得られたもののみには限られない。本発明の２
軸配向フイルムは、その用途によつて適宜の厚さ
となし得るが、通常25〜125μ程度の範囲から選
ばれる。もつとも、この厚さの範囲に限定される
ものではない。
本発明における特性値の測定方法は次の通りで
ある。
(1) 温度膨張率
日本自動制御社製の定荷重伸び試験機
（ITL2型）を恒温恒湿槽内に置き測定を行う。
測定サンプルは予め所定の条件（例えば70℃30
分）で熱処理を施し、このサンプルを試験機に
取付け温度20℃、湿度60％RH（相対湿度）と
温度40℃、湿度60％RHとの間での寸法変化を
読取ることによつて温度膨張率を測定する。こ
のときの原サンプル長は、505mm、サンプル巾
は1/4インチである。測定時に加える加重は
5g／1/4インチ巾当りで一定とした。長いサン
プルが得られない場合は、真空理工社製熱機械
分析装置TM−3000を用い測定することもでき
る。温度膨張率の最大値及び最小値の差をもと
める場合は、TM−3000を用いる。サンプルの
寸法は長さ15mm、巾５mmであつて、温度10℃、
湿度０％RHと温度40℃、相対湿度０％におけ
る寸法変化を読取ることによつて、温度膨張率
の最大と最小との差を知ることができる。両者
の測定法によつて得られた値は完全に一致する
から、いずれの測定法でもよい。
(2) 湿度膨張率
温度膨張率を求める場合と同様に日本自動制
御社製の定荷重伸び試験機を用い、温度40℃、
相対湿度90％の条件で予め処理を施したサンプ
ルを取付け、温度20℃、相対湿度30％と20℃湿
度70％RHの間における寸法変化を読取ること
によつて湿度膨張率を求める。サンプルが長く
とれない場合は温度膨張測定時と同様に真空理
工社製の熱機械分析装置を恒温恒室機に置き、
前記条件のもとで測定を行なつた。この場合も
いずれの方法によつて得られる値を完全に一致
する。
(3) トラツキングずれテスト（温度変化）
トラツキングずれテストとしては次の様な方
法を用いる。金属薄膜をスパツタ法により基材
フイルムの両面に磁気記録層を形成してデイス
ク状に打抜いた金属薄膜よりなる磁気記録フレ
キシブルデイスクを温度15℃湿度60％RHでリ
ングヘツドを用い磁気記録し、そのときの最大
出力と磁気シートの出力エンベロープを測定す
る。次に雰囲気温度を40℃湿度60％RHになる
様に維持して、その温度における最大出力と出
力エンベロープを調べ、15℃湿度60％RHの時
の出力エンベロープと40℃湿度60％RHのとき
の出力エンベロープを比較して、トラツキング
の状態を判定する。この差が小さいほど、優れ
たトラツキング特性を有している。この差が
3db以上になると、トラツキングが悪く、評価
としては×であり、3db以内のものは〇として
評価した。
(4) トラツキングずれテスト（湿度変化）
前項と同様に温度25℃、相対湿度20％の雰囲
気で記録し、更に雰囲気条件を25℃、相対湿度
70％に保持し、25℃、相対湿度20％のときと25
℃相対湿度70％の出力エンベロープを比較す
る。前項と同様にトラツキングの良好性を評価
する。評価方法は３項と同様である。
実施例
次に、実施例により本発明を具体的に説明す
る。
実施例１〜４及び比較例１〜２
二塩基酸成分として、テレフタル酸を85モル
％、イソフタル酸を15モル％、グリコール成分と
して１，４−シクロヘキサンジメタノールを用
い、触媒として酸化チタン0.05モル％とをオート
クレーブに入れ、撹拌下で加熱してエステル交換
し、次いで重縮合して、１，４−シクロヘキサン
ジメタノールとテレフタル酸及びイソフタル酸よ
りなるポリ−１，４−シクロヘキシレンジメチレ
ンテレフタレート系ポリエステルを得た。
一方、テレフタル酸100モル％、１，４−シク
ロヘキサンジメタノール100モル％よりなるポリ
シクロヘキシレン−１，４−ジメチレンテレフタ
レートも同様にして重合を行つた。比較例とし
て、ポリエチレンテレフタレートを常法により重
合した。この２種のポリエステルを300℃で溶融
押出し、1050μの未延伸フイルムを得た。次い
で、90〜120℃にて縦方向に3.3〜3.7倍、100〜
130℃で横方向に3.4〜3.8倍延伸し、更に200〜
240℃において10〜30秒間熱固定して、厚み75μ
の製膜条件の異なつた２軸配向フイルムを得た。
この様にして得られた２軸配合フイルムの両面に
特開昭57−158380号公報等で公知の対向ターゲツ
トを用いたスパッタ法により、厚さが0.5μの
NiFe合金膜と0.4μのCo−Cr合金膜とを順次形成
し、両面２層媒体を形成した。
すなわち、NiFe合金膜はNiFe合金ターゲツト
（Ni：81wt％、330mm×150mm）２枚を120mmの間
隔で対向させた対向ターゲツト式スパツタ装置を
用い両ターゲツトの側方に配した23℃に保つた
350mm直径の回転ドラム上に基材のシートを走行
させながら、アルゴンガス圧1.0Pa（パスカル）、
平均堆積速度0.2μ／minでスパツタを行ない、
0.5μのNiFe合金膜を順に両面に形成した。
そしてCoCr合金膜はCoCr合金ターゲツト
（Cr：17wt％）２枚を用い、同上の装置により、
110℃に保つた回転ドラム上にNiFe合金膜を形成
したシートを走行させながら、平均堆積0.2μ／
minでスパツタを行ない0.4μのCoCr合金膜を順に
両面に形成し、両面２層媒体を作成した。
この後、外径20cmで内径3.8cmの磁気記録フレ
キシブルデイスクに切抜き、記録再生装置により
記録再生操作を行つた。シートレコーダーは
360rpmで回転し、磁気ヘツドの位置はデイスク
の中心より８cmとした。トラツクの巾は300μ、
ヘツドの材質はフエライトであつた。磁気磁気記
録フレキシブルデイスクには1MHzの信号を所定
の条件で記録し、所定の条件で再生して、出力エ
ンベロープの差を測定した。この磁気記録フレキ
シブルデイスクの15℃、60％RHの条件及び25
℃、20％RHときのエンベロープは0.2dB以下で
あつた。
ポリ−１，４−シクロヘキシレンジメチレンテ
レフタレート系ポリエステルを種々に製膜条件を
変化させたものについて、温度、湿度膨張率及び
トラツクずれテストを行い、その結果を第１表に
示した。
TECHNICAL FIELD This invention relates to a magnetic recording flexible disk provided with a magnetic recording layer made of a metal thin film that can avoid tracking errors. More specifically, the present invention relates to a magnetic recording flexible disk provided with a magnetic recording layer made of a metal thin film capable of high track density recording. Prior Art It has long been known that tracking errors can be prevented by providing a general magnetic flexible disk recording/reproducing device with a mechanism for suppressing temperature changes and a special track detection circuit (track servo, etc.). It is being However, these methods require a complicated recording/reproducing device and are therefore not versatile. In practice, measures are taken to create a magnetic flexible disk and prevent tracking errors by selecting materials with as low a coefficient of thermal expansion and a low coefficient of humidity expansion as possible for the base film and magnetic material. ing. However, even with such magnetic flexible disks, high temperatures (40 to 50 degrees Celsius) and/or high humidity (approximately 80 degrees Celsius)
%RH), a tracking error will occur. In particular, low temperature (about 10℃) or low humidity (20%
Magnetic flexible disks recorded under conditions of approximately 25% RH) have the disadvantage that tracking errors occur when played back at room temperature (approximately 25°C) and normal humidity (approximately 60% RH). The problem of a decrease in the output envelope due to this tracking error and a deterioration of the S/N ratio remains unsolved. In recent years, in particular, high-density magnetic recording media have been developed by forming a thin metal film as a magnetic recording layer on thermoplastic, which is a non-magnetic support, by a vacuum deposition method such as vacuum evaporation or sputtering, without using a binder. Many methods have been proposed, such as those using thin films as magnetic recording materials and methods for obtaining metal thin films by electroless plating. In most cases, magnetic flexible disks equipped with a magnetic recording layer made of a thin metal film are related to so-called perpendicular magnetic recording, in which recording is performed by magnetization in the thickness direction of the magnetic recording medium. Improvement alone is not sufficient to increase the density of magnetic recording, and high-density magnetic recording can be achieved by simultaneously satisfying the improvement of track density due to the temperature and humidity expansion coefficient of the base film. It is something. A magnetic recording flexible disk made of a metal thin film capable of such high track density recording has not yet been obtained. Purpose of the Invention As a result of repeated research in order to eliminate the above-mentioned drawbacks, the present inventor has found that a
By adjusting the temperature and humidity expansion coefficient of the axially oriented film to a specific range, a film with high dimensional stability can be obtained, and by using this film as a base material, a magnetic recording flexible disk made of a thin metal film can be manufactured. The inventors have discovered that the occurrence of king mistakes can be avoided and have arrived at the present invention. The purpose of this invention is to provide a magnetic recording flexible disk made of a metal thin film that has been improved to expand the range of usable atmospheric conditions, temperature and humidity, and to prevent tracking errors from occurring even under high temperature and high humidity conditions. . Furthermore, a magnetic recording flexible disk made of a metal thin film with high dimensional stability under temperature and humidity enables higher density magnetic recording, especially improved track density. It is also another object of the invention to provide a disk. Structure of the Invention The present invention uses a biaxially oriented film as a base material made of poly-1,4-cyclohexylene dimethylene terephthalate polyester in which 80 mol% or more of the acid component is composed of terephthalic acid. The maximum temperature expansion coefficient in the plane including the width direction is 9 to 35 × 10 -6 °C -1 , the maximum humidity expansion coefficient is 0 to 8.0 × 10 -6 °C (%RH) -1 , and the maximum and minimum The difference in temperature expansion coefficient is 0 to 8.0 × 10 -6 ℃ -1 , and the difference in maximum and minimum humidity expansion coefficient is 0 to 3.0 × 10 -6 (%RH) -1
This is a magnetic recording flexible disk which is provided with a magnetic recording layer made of a metal thin film. This magnetic recording flexible disk has the following features:
Vacuum deposition, sputtering, ion plating, C.
It can be obtained by using methods such as VD (Chemical Vapor Deposition) or electroless plating. In addition, the poly-1,4-cyclohexylene dimethylene terephthalate-based polyester biaxially oriented film can be manufactured by appropriately controlling the film forming conditions so as to satisfy the above-mentioned temperature and humidity expansion coefficient conditions. Can be done. The magnetic recording flexible disk of the present invention is composed of a magnetic layer made of a thin metal film and a base film. As mentioned above, methods for forming such metal thin films include vacuum evaporation, sputtering, ion plating, and CVD (Chemical Vapor Deposition).
For forming these metal thin films, all conventionally known methods can be used. In the case of the vacuum evaporation method, the evaporated metal in a tungsten boat or alumina hearth is evaporated under a vacuum of 10 -4 to 10 -6 Torr by resistance heating, high-frequency heating, electron beam heating, etc., and deposited on the support. urge Fe, Ni, Co, and alloys thereof are usually used as the deposited metal. Further, a reactive vapor deposition method for obtaining an iron oxide thin film by evaporating Fe in an O 2 atmosphere can also be applied to the present invention. In the ion plating method, DC glow discharge and RF glow discharge are generated in an atmosphere mainly composed of an inert gas of 10 -4 to 10 -3 Torr, and metal is evaporated during the discharge. Ar is usually used as the inert gas. 10 -3 in the spatuta method
A glow discharge is generated in an atmosphere containing Ar as the main component at ~10 -1 Torr, and the generated Ar ions knock out atoms on the target surface. Methods for generating glow discharge include DC two-pole, three-pole sputtering methods, and high-frequency sputtering methods. There is also a magnetron sputtering method that uses magnetron discharge. The thickness of the magnetic thin film must be such that it provides sufficient signal output as a high density magnetic recording medium. Therefore, the thickness of the magnetic thin film varies depending on the thin film formation method and application, but generally it is 0.02 to 1.5 μm (200 to 200 μm).
15000Å). Methods for forming the magnetic thin film for longitudinal recording include methods such as vapor deposition (thermal vapor deposition, electron beam vapor deposition, etc.), sputtering (dipolar DC sputtering, high frequency sputtering, etc.). In the case of vapor deposition, a ferromagnetic metal such as Co is continuously obliquely vapor-deposited onto a non-magnetic plastic support so that the axis of easy magnetization is expressed in the horizontal direction of the tape, and by repeated lamination, crystal magnetic anisotropy is achieved. The tape exhibits anisotropy and shape anisotropy in the horizontal direction of the tape. Therefore, the total metal thin film thickness is 0.02 to 0.5 μm (200
~5000Å). In addition to the method for forming magnetic thin films for longitudinal recording as described above, for flexible disks, as a method that enables high-density digital recording, a method for forming an easy magnetization axis in the perpendicular direction of a non-magnetic support, for example, using Co.
By mixing an appropriate amount of Cr (10 to 20%), the generated demagnetizing field is suppressed and an axis of easy magnetization is developed in the vertical direction.
A perpendicular magnetic recording method in which recording is performed in a direction perpendicular to the substrate surface can also be applied. Normally, in the spatsuta method, 0.2 to 1.5 μm thick Co~
Cr alloy is used. At this time, a non-magnetic support and
A magnetic flux concentrator thin film made of a high magnetic permeability material such as permalloy (Fe-Ni) or supermalloy can be disposed between magnetic recording layers having an axis of easy magnetization in the perpendicular direction. The high permeability material used as the magnetic flux concentrator is formed by sputtering, and the film thickness is 0.1 to 1 μm.
It is a thin film layer with a low coercive force (less than 50 Oe) of (1000 to 10000 Å). At this time, the Co--Cr film thickness of the magnetic recording layer is formed to be approximately 0.2 to 1.5 μm (2000 to 15000 Å). The magnetic recording layer made of a metal thin film only needs to have at least one magnetic recording layer on the front and back sides of the base film, but as disclosed in Japanese Patent Publication No. 1982-91,
It may have a soft magnetic layer such as a NiFe alloy thin film,
Further, a suitable adhesive layer may be provided between the base film and the metal thin film, and a protective layer may be provided on the metal thin film. Poly-1, which is the base film in the present invention,
As a 4-cyclohexylene dimethylene terephthalate polyester, 80 of the dibasic acid components
More than mol% of the glycol is composed of terephthalic acid, and the glycol component is a glycol selected from the cis or trans isomers of 1,4-cyclohexanedimethanol. Examples of dibasic acid components other than terephthalic acid include dibasic acids such as isophthalic acid, phthalic acid, adipic acid, sebacic acid, succinic acid, and oxalic acid. Preferably it is isophthalic acid. 1,4-Cyclohexane dimethanol used in the present invention is produced by catalytic reduction of dimethyl terephthalate or terephthalic acid.
There is no problem with products manufactured by either method. Although the ratio of the cis isomer to the trans isomer of 1,4-cyclohexanedimethanol is not particularly limited, it is preferably within the range of cis isomer/trans isomer = 4/6 to 0/10. The poly-1,4-cyclohexylene dimethylene terephthalate polyester contains, for example, stabilizers such as phosphoric acid, phosphorous acid and their esters, titanium dioxide, particulate silica, kaolin, calcium carbonate, calcium phosphate, etc. It may contain a dissipating agent, a lubricant, etc. The poly-1,4-cyclohexylene dimethylene terephthalate biaxially oriented film used in the present invention has a maximum thermal expansion coefficient of 9 to 35 in a plane including the longitudinal direction and width direction of the film.
×10 -6 ℃ -1 , preferably 9 to 25 × 10 -6 ℃ -1 , maximum humidity expansion coefficient 0 to 8.0 × 10 -6 (%RH) -1 , preferably 0 to 5.0 × 10 -6 (%RH) -1 , and the difference in temperature expansion coefficient between the maximum and minimum is 0 to 8.0×10 -6 ℃ -1 ,
Preferably, the difference between the maximum and minimum humidity expansion coefficients is 0 to 5.0 × 10 -6 °C -1 , preferably 0 to 3.0 × 10 -6 (%RH) -1 , preferably 0 to 2.5 × 10 -6 (%RH). ) -1 . When the temperature and humidity expansion coefficient of the film base material satisfy this range, tracking errors of the flexible disk can be prevented and it can be used in a wide temperature and humidity range. If the temperature or humidity expansion coefficient exceeds the range specified above, if the magnetic recording flexible disk is reproduced at a temperature different from that recorded in the atmosphere,
Due to the difference in temperature expansion coefficient and humidity expansion coefficient, the magnetic flexible disk stretches differently from the center, causing a misalignment between the magnetic head and the recording track, resulting in tracking errors. As a result, the output changes,
Causes dropout. With current technology, the maximum thermal expansion coefficient of polyethylene terephthalate polyester film, which is most commonly used for magnetic recording flexible disks, is approximately 17 × 10 -6 °C -1 , and the difference between the maximum and minimum thermal expansion coefficients is Although the temperature expansion coefficient is about 8×10 -6 °C -1 , which is almost the same as that of the recording/reproducing device, it is not possible to completely prevent track deviation due to the difference in the temperature expansion coefficient in the in-plane direction. In addition, the humidity tensile rate is approximately 11×10 -6 (%
RH) The track deviation corresponding to the humidity change, which is quite large at about -1 , is quite large because the humidity expansion coefficient of the recording/reproducing device can be regarded as 0. On the other hand, by using the poly-1,4-cyclohexylene dimethylene terephthalate-based polyester biaxially oriented film of the present invention, the temperature expansion is greater than that of the commonly used biaxially oriented film made of polyethylene terephthalate-based polyester. The track deviation due to humidity expansion is small, and the track deviation is further suppressed by reducing the difference between the maximum value and minimum value of the temperature expansion coefficient and the difference between the maximum value and the minimum value of the humidity expansion coefficient. It can be used in environments with a wide temperature and humidity range without any problems. Furthermore, a magnetic recording flexible disk with high density magnetic recording can be obtained using this base film. As a method for forming a poly-1,4-cyclohexylene dimethylene terephthalate-based polyester film to obtain the above-mentioned expansion characteristics, a method similar to that for forming a normal polyester film such as polyethylene terephthalate can be applied. For example, T
- It is possible to produce an unstretched film melt-extruded by a die method, an inflation method, or the like. Furthermore, it can be biaxially stretched to form a biaxially oriented film. The stretching temperature at this time is almost the same as that for polyethylene terephthalate film, but the glass transition temperature and melting point vary depending on the terephthalic acid content in the poly-1,4-cyclohexylene dimethylene terephthalate polyester. Therefore, it is necessary to appropriately select the melting temperature and the temperature of the casting drum in accordance with this. The stretching temperature is usually 80 to 140°C, and the stretching ratio is 3.0 to 5.0 times in the longitudinal direction, preferably 3.5.
~4.5x, 3.0~5.0x laterally, preferably 3.5~
Select around 4.5x. The obtained biaxially oriented film is heated at 150 to 260°C (preferably 180 to 250°C).
By heat setting for 100 seconds, the temperature of the present invention,
A film with small track deviation due to humidity expansion can be obtained. However, the biaxially oriented film made of poly-1,4-cyclohexylene dimethylene terephthalate polyester of the present invention is not limited to that obtained by such a method. 2 of the present invention
The axially oriented film can have an appropriate thickness depending on its use, but is usually selected from a range of about 25 to 125 microns. However, the thickness is not limited to this range. The method for measuring characteristic values in the present invention is as follows. (1) Temperature expansion coefficient Measurement is performed by placing a constant load elongation tester (ITL2 type) manufactured by Japan Automatic Control Co., Ltd. in a constant temperature and humidity chamber.
Measurement samples were prepared in advance under predetermined conditions (e.g. 70°C 30°C).
Temperature expansion can be determined by heat-treating the sample for 20 minutes), then attaching the sample to a test machine and reading the dimensional change between 20℃ and 60%RH (relative humidity) and 40℃ and 60%RH. Measure the rate. The original sample length at this time was 505 mm, and the sample width was 1/4 inch. The weight applied during measurement is
It was fixed at 5g/1/4 inch width. If a long sample cannot be obtained, measurement can be performed using a thermomechanical analyzer TM-3000 manufactured by Shinku Riko Co., Ltd. When determining the difference between the maximum and minimum thermal expansion coefficients, use TM-3000. The dimensions of the sample were 15 mm in length and 5 mm in width, and the temperature was 10°C.
By reading the dimensional changes at a humidity of 0% RH, a temperature of 40° C., and a relative humidity of 0%, the difference between the maximum and minimum thermal expansion coefficients can be determined. Since the values obtained by both measurement methods completely match, either measurement method may be used. (2) Humidity expansion coefficient As in the case of calculating the temperature expansion coefficient, a constant load elongation tester manufactured by Japan Automatic Control Co., Ltd. was used, and the temperature was 40℃.
The humidity expansion coefficient is determined by attaching a sample that has been pretreated at a relative humidity of 90% and reading the dimensional changes between the temperature of 20°C and the relative humidity of 30% and 20°C and humidity of 70%RH. If the sample cannot be taken for a long time, place the thermomechanical analyzer manufactured by Shinku Riko Co., Ltd. in a constant temperature room machine, as in the case of measuring thermal expansion.
Measurements were carried out under the above conditions. In this case as well, the values obtained by either method are completely consistent. (3) Tracking deviation test (temperature change) The following method is used for the tracking deviation test. Magnetic recording layers are formed on both sides of a base film using a sputtering method, and a magnetic recording flexible disk is made of a metal thin film punched out into a disk shape. When measuring the maximum output and output envelope of the magnetic sheet. Next, maintain the ambient temperature at 40℃ and humidity 60%RH, and check the maximum output and output envelope at that temperature.The output envelope at 15℃ and humidity 60%RH and at 40℃ and humidity 60%RH. The tracking status is determined by comparing the output envelopes of . The smaller this difference is, the better the tracking characteristics are. This difference
If it exceeds 3 db, the tracking is poor and is rated as ×, and if it is within 3 db, it is rated as ○. (4) Tracking deviation test (humidity change) Recording was performed in an atmosphere with a temperature of 25℃ and relative humidity of 20% as in the previous section, and the atmospheric conditions were further changed to 25℃ and relative humidity.
When kept at 70%, 25℃ and 20% relative humidity and 25
Compare the output envelopes at 70% relative humidity in °C. Evaluate the tracking quality in the same way as in the previous section. The evaluation method is the same as in Section 3. EXAMPLES Next, the present invention will be specifically explained using examples. Examples 1 to 4 and Comparative Examples 1 to 2 As the dibasic acid component, 85 mol% of terephthalic acid, 15 mol% of isophthalic acid, 1,4-cyclohexanedimethanol as the glycol component, and 0.05 mol of titanium oxide as the catalyst. % in an autoclave, heated under stirring to transesterify, and then polycondensed to form a poly-1,4-cyclohexylene dimethylene terephthalate system consisting of 1,4-cyclohexanedimethanol, terephthalic acid, and isophthalic acid. Polyester was obtained. On the other hand, polycyclohexylene-1,4-dimethylene terephthalate consisting of 100 mol% of terephthalic acid and 100 mol% of 1,4-cyclohexanedimethanol was similarly polymerized. As a comparative example, polyethylene terephthalate was polymerized by a conventional method. These two types of polyester were melt-extruded at 300°C to obtain an unstretched film of 1050μ. Then, 3.3 to 3.7 times in the longitudinal direction at 90 to 120℃, 100 to
Stretched 3.4 to 3.8 times in the transverse direction at 130℃, and further stretched 200 to 3.8 times.
Heat set at 240℃ for 10-30 seconds to a thickness of 75μ
Biaxially oriented films were obtained under different film forming conditions.
Both sides of the biaxially compounded film obtained in this way were sputtered to a thickness of 0.5μ using a facing target as disclosed in Japanese Patent Application Laid-open No. 57-158380.
A NiFe alloy film and a 0.4μ Co-Cr alloy film were sequentially formed to form a double-sided double-layered medium. That is, the NiFe alloy film was prepared by using a facing target sputtering device in which two NiFe alloy targets (Ni: 81 wt%, 330 mm x 150 mm) were placed facing each other at a spacing of 120 mm, and were placed on the sides of both targets to maintain a temperature of 23°C.
While running the base material sheet on a rotating drum with a diameter of 350 mm, the argon gas pressure was 1.0 Pa (Pascal),
Sputtering was performed at an average deposition rate of 0.2μ/min,
A 0.5μ NiFe alloy film was sequentially formed on both sides. The CoCr alloy film was made using the same equipment as above using two CoCr alloy targets (Cr: 17wt%).
While running a sheet on which a NiFe alloy film was formed on a rotating drum kept at 110℃, the average deposition rate was 0.2μ/
A CoCr alloy film of 0.4 μm was sequentially formed on both sides by sputtering at a speed of 10 min to create a double-sided two-layer medium. Thereafter, a magnetic recording flexible disk having an outer diameter of 20 cm and an inner diameter of 3.8 cm was cut out, and recording and reproducing operations were performed using a recording and reproducing device. The sheet recorder
It rotated at 360 rpm, and the magnetic head was positioned 8 cm from the center of the disk. The width of the track is 300μ,
The material of the head was ferrite. A 1 MHz signal was recorded on the magnetic recording flexible disk under predetermined conditions, reproduced under predetermined conditions, and the difference in output envelope was measured. The conditions of this magnetic recording flexible disk are 15℃, 60%RH and 25℃.
The envelope at ℃ and 20% RH was 0.2 dB or less. Poly-1,4-cyclohexylene dimethylene terephthalate polyesters under various film forming conditions were subjected to temperature, humidity expansion coefficient and track deviation tests, and the results are shown in Table 1.
【表】
以上の結果から明らかな通り、温湿度膨張率が
適当範囲のものは実施例１〜６で示したようにト
ラツキングミスが改善されており、高温高湿雰囲
気において磁気デイスクの記録再生等の使用が可
能であることが判る。これに対し、比較例１〜３
においてはトラツキングミスが発生している。こ
のように本発明のデイスクは高トラツク密度のフ
レキシブルデイスクとして工業的価値が高いもの
であることが判つた。
発明の効果
本発明の磁気記録フレキシブルデイスクは、特
定のポリエステル、即ちポリ−１，４−シクロヘ
キシレンジメチレンテレフタレートを主成分とし
て、長手方向と幅方向にバランスするように２軸
延伸を施したものを基材とし、このポリエステル
フイルムの表面に磁性層を設けたたものである。
基材フイルムが、所定の温度膨張率と湿度膨張率
とを備えた場合には、磁気デイスクとしてトラツ
ク密度を高めても、トラツキングミスが生じない
ので、高密度記録が可能となる利点を備えてい
る。更に、この磁気デイスクは、記録と再生との
温度、湿度条件が相違してもトラツキングミスが
ないという利点も備えている。従つて、本発明の
フレキシブルデイスクは、雰囲気の変化に耐えら
れる、適用範囲の広いものである。[Table] As is clear from the above results, tracking errors are improved as shown in Examples 1 to 6 when the temperature/humidity expansion coefficient is in an appropriate range, and recording/reproduction of magnetic disks in a high temperature/humid atmosphere is possible. It turns out that it is possible to use . On the other hand, Comparative Examples 1 to 3
Tracking errors occur in this case. Thus, it has been found that the disk of the present invention has high industrial value as a flexible disk with high track density. Effects of the Invention The magnetic recording flexible disk of the present invention is made of a specific polyester, namely poly-1,4-cyclohexylene dimethylene terephthalate, which is biaxially stretched so as to be balanced in the longitudinal direction and the width direction. A magnetic layer is provided on the surface of this polyester film.
If the base film has a predetermined temperature expansion coefficient and humidity expansion coefficient, tracking errors will not occur even if the track density is increased as a magnetic disk, which has the advantage of enabling high-density recording. ing. Furthermore, this magnetic disk has the advantage that there is no tracking error even if the temperature and humidity conditions between recording and reproduction are different. Therefore, the flexible disk of the present invention can withstand changes in atmosphere and has a wide range of applications.
Claims (1)
る磁気記録層を設けた磁気記録フレキシブルデイ
スクにおいて、ポリエステルフイルムが実質的に
ポリ−１，４−シクロヘキシレンジメチレンテレ
フタレートからなる二軸配向フイルムであり、該
フイルムの長手方向及び幅方向を含む面での最大
の温度膨張率が９〜35×10-6℃-1、最大の湿度膨
張率が０〜8.0×10-6（％RH）-1、最大と最小との
温度膨張率の差が０〜8.0×10-6℃-1、及び最大
と最小との湿度膨張率の差が０〜3.0×10-6（％
RH）-1であることを特徴とする金属薄膜よりな
る磁気記録フレキシブルデイスク。1. In a magnetic recording flexible disk in which a magnetic recording layer made of a metal thin film is provided on a polyester film base material, the polyester film is a biaxially oriented film made essentially of poly-1,4-cyclohexylene dimethylene terephthalate; The maximum temperature expansion coefficient in the plane including the longitudinal and width directions is 9 to 35 × 10 -6 °C -1 , the maximum humidity expansion coefficient is 0 to 8.0 × 10 -6 (%RH) -1 , and the maximum The difference in temperature expansion coefficient from the minimum is 0 to 8.0 × 10 -6 °C -1 , and the difference in humidity expansion coefficient between the maximum and minimum is 0 to 3.0 × 10 -6 (%
RH) -1 A magnetic recording flexible disk made of a thin metal film.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19338283A JPS6085437A (en) | 1983-10-18 | 1983-10-18 | Flexible disc for magnetic recording |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP19338283A JPS6085437A (en) | 1983-10-18 | 1983-10-18 | Flexible disc for magnetic recording |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6085437A JPS6085437A (en) | 1985-05-14 |
| JPH0263256B2 true JPH0263256B2 (en) | 1990-12-27 |
Family
ID=16306993
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP19338283A Granted JPS6085437A (en) | 1983-10-18 | 1983-10-18 | Flexible disc for magnetic recording |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS6085437A (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS62124926A (en) * | 1985-11-27 | 1987-06-06 | Teijin Ltd | Polyester film |
| JP2684734B2 (en) * | 1988-12-16 | 1997-12-03 | 東レ株式会社 | Film for heat ray reflection |
| JPH02164532A (en) * | 1988-12-16 | 1990-06-25 | Toray Ind Inc | Flexible circuit board |
| US7147927B2 (en) | 2002-06-26 | 2006-12-12 | Eastman Chemical Company | Biaxially oriented polyester film and laminates thereof with copper |
| US7524920B2 (en) | 2004-12-16 | 2009-04-28 | Eastman Chemical Company | Biaxially oriented copolyester film and laminates thereof |
| JP5694865B2 (en) * | 2011-06-22 | 2015-04-01 | 帝人株式会社 | Polyester composition, method for producing the same, and biaxially oriented polyester film |
-
1983
- 1983-10-18 JP JP19338283A patent/JPS6085437A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS6085437A (en) | 1985-05-14 |
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