JPH04372712A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPH04372712A JPH04372712A JP3151390A JP15139091A JPH04372712A JP H04372712 A JPH04372712 A JP H04372712A JP 3151390 A JP3151390 A JP 3151390A JP 15139091 A JP15139091 A JP 15139091A JP H04372712 A JPH04372712 A JP H04372712A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- layer
- nonmagnetic
- magnetic layer
- thickness
- 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.)
- Pending
Links
- 239000011256 inorganic filler Substances 0.000 claims description 7
- 229910003475 inorganic filler Inorganic materials 0.000 claims description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims 1
- 229910052799 carbon Inorganic materials 0.000 claims 1
- 239000010410 layer Substances 0.000 abstract description 57
- 239000006229 carbon black Substances 0.000 abstract description 21
- 239000000945 filler Substances 0.000 abstract description 3
- 239000011247 coating layer Substances 0.000 abstract description 2
- 239000003973 paint Substances 0.000 description 35
- 239000002609 medium Substances 0.000 description 18
- 239000002245 particle Substances 0.000 description 17
- 239000006247 magnetic powder Substances 0.000 description 12
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 10
- 238000000034 method Methods 0.000 description 9
- 230000000052 comparative effect Effects 0.000 description 8
- 239000000314 lubricant Substances 0.000 description 8
- 239000000203 mixture Substances 0.000 description 7
- VTYYLEPIZMXCLO-UHFFFAOYSA-L Calcium carbonate Chemical compound [Ca+2].[O-]C([O-])=O VTYYLEPIZMXCLO-UHFFFAOYSA-L 0.000 description 6
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 6
- 238000001035 drying Methods 0.000 description 6
- -1 talc or clay Natural products 0.000 description 6
- 241000872198 Serjania polyphylla Species 0.000 description 5
- 239000011230 binding agent Substances 0.000 description 5
- 239000000843 powder Substances 0.000 description 5
- 235000014113 dietary fatty acids Nutrition 0.000 description 4
- 239000000194 fatty acid Substances 0.000 description 4
- 229930195729 fatty acid Natural products 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 229920005596 polymer binder Polymers 0.000 description 4
- 239000002491 polymer binding agent Substances 0.000 description 4
- 239000004576 sand Substances 0.000 description 4
- 229910000019 calcium carbonate Inorganic materials 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 150000004665 fatty acids Chemical class 0.000 description 3
- 239000010419 fine particle Substances 0.000 description 3
- AJCDFVKYMIUXCR-UHFFFAOYSA-N oxobarium;oxo(oxoferriooxy)iron Chemical compound [Ba]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O AJCDFVKYMIUXCR-UHFFFAOYSA-N 0.000 description 3
- 230000003746 surface roughness Effects 0.000 description 3
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 2
- OYHQOLUKZRVURQ-HZJYTTRNSA-N Linoleic acid Chemical compound CCCCC\C=C/C\C=C/CCCCCCCC(O)=O OYHQOLUKZRVURQ-HZJYTTRNSA-N 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- 238000010521 absorption reaction Methods 0.000 description 2
- 239000006185 dispersion Substances 0.000 description 2
- POULHZVOKOAJMA-UHFFFAOYSA-N dodecanoic acid Chemical compound CCCCCCCCCCCC(O)=O POULHZVOKOAJMA-UHFFFAOYSA-N 0.000 description 2
- IPCSVZSSVZVIGE-UHFFFAOYSA-N hexadecanoic acid Chemical compound CCCCCCCCCCCCCCCC(O)=O IPCSVZSSVZVIGE-UHFFFAOYSA-N 0.000 description 2
- OYHQOLUKZRVURQ-IXWMQOLASA-N linoleic acid Natural products CCCCC\C=C/C\C=C\CCCCCCCC(O)=O OYHQOLUKZRVURQ-IXWMQOLASA-N 0.000 description 2
- 235000020778 linoleic acid Nutrition 0.000 description 2
- 229920000139 polyethylene terephthalate Polymers 0.000 description 2
- 239000005020 polyethylene terephthalate Substances 0.000 description 2
- 238000002203 pretreatment Methods 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- UBXAKNTVXQMEAG-UHFFFAOYSA-L strontium sulfate Chemical compound [Sr+2].[O-]S([O-])(=O)=O UBXAKNTVXQMEAG-UHFFFAOYSA-L 0.000 description 2
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 description 1
- PSBDWGZCVUAZQS-UHFFFAOYSA-N (dimethylsulfonio)acetate Chemical group C[S+](C)CC([O-])=O PSBDWGZCVUAZQS-UHFFFAOYSA-N 0.000 description 1
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 description 1
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 description 1
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 239000005639 Lauric acid Substances 0.000 description 1
- 239000000020 Nitrocellulose Substances 0.000 description 1
- 239000005642 Oleic acid Substances 0.000 description 1
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 description 1
- 235000021314 Palmitic acid Nutrition 0.000 description 1
- 239000004793 Polystyrene Substances 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 1
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 239000003082 abrasive agent Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 150000001298 alcohols Chemical class 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
- 125000003277 amino group Chemical group 0.000 description 1
- 239000004760 aramid Substances 0.000 description 1
- 229920003235 aromatic polyamide Polymers 0.000 description 1
- 238000003490 calendering Methods 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 229910000423 chromium oxide Inorganic materials 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 238000004891 communication Methods 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- PMHQVHHXPFUNSP-UHFFFAOYSA-M copper(1+);methylsulfanylmethane;bromide Chemical compound Br[Cu].CSC PMHQVHHXPFUNSP-UHFFFAOYSA-M 0.000 description 1
- 230000007423 decrease Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 239000002612 dispersion medium Substances 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- 230000004907 flux Effects 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 description 1
- ZLNQQNXFFQJAID-UHFFFAOYSA-L magnesium carbonate Chemical compound [Mg+2].[O-]C([O-])=O ZLNQQNXFFQJAID-UHFFFAOYSA-L 0.000 description 1
- 239000001095 magnesium carbonate Substances 0.000 description 1
- 229910000021 magnesium carbonate Inorganic materials 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- WQEPLUUGTLDZJY-UHFFFAOYSA-N n-Pentadecanoic acid Natural products CCCCCCCCCCCCCCC(O)=O WQEPLUUGTLDZJY-UHFFFAOYSA-N 0.000 description 1
- 229930014626 natural product Natural products 0.000 description 1
- 150000004767 nitrides Chemical class 0.000 description 1
- 229920001220 nitrocellulos Polymers 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 description 1
- TWNQGVIAIRXVLR-UHFFFAOYSA-N oxo(oxoalumanyloxy)alumane Chemical compound O=[Al]O[Al]=O TWNQGVIAIRXVLR-UHFFFAOYSA-N 0.000 description 1
- 125000000951 phenoxy group Chemical group [H]C1=C([H])C([H])=C(O*)C([H])=C1[H] 0.000 description 1
- 229920003207 poly(ethylene-2,6-naphthalate) Polymers 0.000 description 1
- 229920002492 poly(sulfone) Polymers 0.000 description 1
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 239000011112 polyethylene naphthalate Substances 0.000 description 1
- 229920001228 polyisocyanate Polymers 0.000 description 1
- 239000005056 polyisocyanate Substances 0.000 description 1
- 229920002223 polystyrene Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 239000012744 reinforcing agent Substances 0.000 description 1
- 229920006395 saturated elastomer Polymers 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 125000000542 sulfonic acid group Chemical group 0.000 description 1
- 150000003467 sulfuric acid derivatives Chemical class 0.000 description 1
- 239000002344 surface layer Substances 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- TUNFSRHWOTWDNC-HKGQFRNVSA-N tetradecanoic acid Chemical compound CCCCCCCCCCCCC[14C](O)=O TUNFSRHWOTWDNC-HKGQFRNVSA-N 0.000 description 1
- OGIDPMRJRNCKJF-UHFFFAOYSA-N titanium oxide Inorganic materials [Ti]=O OGIDPMRJRNCKJF-UHFFFAOYSA-N 0.000 description 1
- 235000021122 unsaturated fatty acids Nutrition 0.000 description 1
- 150000004670 unsaturated fatty acids Chemical class 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Landscapes
- Pigments, Carbon Blacks, Or Wood Stains (AREA)
- Paints Or Removers (AREA)
- Magnetic Record Carriers (AREA)
Abstract
Description
【０００１】0001
【産業上の利用分野】本発明は、耐久性に優れた高記録
密度用の磁気記録媒体に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a highly durable magnetic recording medium for high recording density.
【０００２】0002
【従来の技術】磁気記録媒体はこれまで常に記録密度の
向上と耐久性，信頼性の向上に取り組んできたが、近年
映像情報通信機器の小型化が一段と進むことにより、益
々それらに対する要求が厳しくなってきている。さらに
、従来の機器では媒体との信号のやり取りにおいては、
低域すなわち媒体上での記録密度が低い範囲の周波数帯
も用いられてきたのに対し、近年の機器においては、低
域周波数帯を用いず全ての情報を高域周波数帯の信号で
やり取りするシステムまでも開発されてきており、高い
耐久性，信頼性の確保とともに高密度記録における媒体
の出力の向上はきわめて重要になってきている。[Prior Art] Magnetic recording media have always been improved in recording density, durability, and reliability, but as video information communication equipment has become more compact in recent years, requirements for these have become increasingly strict. It has become to. Furthermore, with conventional equipment, when exchanging signals with the medium,
While low frequency bands, i.e. frequency bands with low recording density on the medium, have been used, recent devices do not use low frequency bands and exchange all information using signals in high frequency bands. Even systems have been developed, and it has become extremely important to ensure high durability and reliability as well as improve the output of the medium for high-density recording.
【０００３】特公平３−１２３７０号公報には保磁力の
高いメタル磁性体を用いる磁気記録媒体が提案されてい
るが、その磁性層膜厚は４μｍであり、このままでは厚
み損失のため出力が十分でなく１ｂｉｔ／２．５μｍ２
以上の媒体上での記録密度を確保することができない。
ここでこの厚み損失とは、磁性層の厚みδが媒体上の記
録波長λに比べて十分大きいと媒体の内部で磁束はルー
プをつくりヘッドで拾われない現象をいう。[0003] Japanese Patent Publication No. 3-12370 proposes a magnetic recording medium using a metal magnetic material with high coercive force, but the thickness of the magnetic layer is 4 μm, and as it is, the output is insufficient due to thickness loss. not 1 bit/2.5 μm2
It is not possible to ensure the recording density on the above medium. Here, the thickness loss refers to a phenomenon in which when the thickness δ of the magnetic layer is sufficiently larger than the recording wavelength λ on the medium, the magnetic flux forms a loop inside the medium and is not picked up by the head.
【０００４】0004
【発明が解決しようとする課題】磁気記録媒体において
短波長記録における出力を向上させるには、いわゆる磁
性層の保磁力を高くしスペーシングロスを少なくするた
め磁性層の表面を平滑にするとともに、厚み損失を少な
くするため磁性層の厚みを薄くすればよいがこのような
磁気記録媒体は耐久性，信頼性に著しく劣る問題点のあ
ることが明らかとなった。[Problems to be Solved by the Invention] In order to improve the output in short wavelength recording in a magnetic recording medium, it is necessary to increase the coercive force of the magnetic layer and smooth the surface of the magnetic layer in order to reduce spacing loss. Although it is possible to reduce the thickness loss by reducing the thickness of the magnetic layer, it has become clear that such magnetic recording media have the problem of significantly inferior durability and reliability.
【０００５】したがって、この発明は上記問題点を解決
することにより、耐久性，信頼性の低下を伴わずして短
波長記録における出力にすぐれる磁気記録媒体を提供す
ることを目的としている。[0005] Accordingly, an object of the present invention is to solve the above-mentioned problems, thereby providing a magnetic recording medium that has excellent output in short wavelength recording without deteriorating durability or reliability.
【０００６】[0006]
【課題を解決するための手段】上記目的を達成するため
、著者らは鋭意検討した結果、従来の塗布型磁気記録媒
体が耐久性，信頼性について長年の実績があるのは、磁
性層の塗布厚みが従来の技術では数μｍありこの層に含
まれている潤滑剤が重要な役割を果たしており、厚みが
薄くなることによって潤滑剤が十分でなくなることによ
り信頼性，耐久性に問題が生ずることを知り、この発明
をなすにいたった。[Means for solving the problem] In order to achieve the above objective, the authors have conducted extensive studies and found that the reason why conventional coated magnetic recording media have a long track record of durability and reliability is that the magnetic layer is coated. With conventional technology, the thickness is several micrometers, and the lubricant contained in this layer plays an important role.As the thickness decreases, the lubricant becomes insufficient, causing problems in reliability and durability. This led me to this invention.
【０００７】すなわち、この発明は非磁性支持体上に非
磁性層とさらにその上に磁性層を設け、該非磁性層中に
平均粒径３０ｎｍ以下でかつストラクチャーがあまり発
達していないカーボンブラックと無機フィラーとを含む
磁気記録媒体に関する。塗布型磁気記録媒体の短波長記
録における出力を向上させるには保磁力が高く表面が平
滑な磁性層の厚みを薄くする必要があり、耐久性，信頼
性を確保するにはこの磁性層の厚みを厚くする必要があ
る。この問題点を解決するためには、厚みの薄い高保磁
力磁性層の下に厚みの厚い表面が平滑な非磁性の塗布層
を設ければよい。That is, the present invention provides a nonmagnetic layer on a nonmagnetic support and a magnetic layer thereon, and in the nonmagnetic layer, carbon black with an average particle size of 30 nm or less and a poorly developed structure and an inorganic The present invention relates to a magnetic recording medium containing a filler. To improve the short wavelength recording output of coated magnetic recording media, it is necessary to reduce the thickness of the magnetic layer, which has a high coercive force and a smooth surface.In order to ensure durability and reliability, the thickness of this magnetic layer must be reduced. It is necessary to make it thicker. In order to solve this problem, a thick nonmagnetic coating layer with a smooth surface may be provided under the thin high coercive force magnetic layer.
【０００８】この発明で非磁性層とは主として非磁性粉
体と高分子バインダーおよび潤滑剤とからなる層をいう
。非磁性粉体としては平均粒径３０ｎｍ以下でかつスト
ラクチャーがあまり発達していないカーボンブラックと
無機フィラーとを含むことが望ましい。カーボンブラッ
クとして平均粒径が３０ｎｍより大きいものを用いると
、十分分散された塗料として塗布しても非磁性層の表面
平滑性が十分でなく本発明の目的を達成することができ
ない。またカーボンブラックの平均粒径が３０ｎｍ以下
であってもストラクチャーが発達している場合は同じく
本発明の目的を達成することができない。ここでいうス
トラクチャーとはカーボンブラックのチェイン構造をい
い、ストラクチャーが大きく発達しているカーボンブラ
ックの場合は塗料分散時に十分平均粒径まで分散するこ
とができず平均粒径が３０ｎｍ以下であっても実際の粒
径はこれよりはるかに大きくなるからである。カーボン
ブラックのストラクチャーの程度は通常ＤＢＰを用いた
カーボンブラック１００ｇあたりの吸油量を用いて表さ
れるが、この値が２５０ｍｌを越えるものは本発明の目
的を達成することができない。[0008] In this invention, the nonmagnetic layer refers to a layer mainly composed of nonmagnetic powder, a polymer binder, and a lubricant. The non-magnetic powder preferably contains carbon black with an average particle size of 30 nm or less and a poorly developed structure, and an inorganic filler. If carbon black having an average particle size larger than 30 nm is used, the surface smoothness of the nonmagnetic layer will not be sufficient even if it is applied as a sufficiently dispersed paint, making it impossible to achieve the object of the present invention. Further, even if the average particle size of carbon black is 30 nm or less, if the structure is developed, the object of the present invention cannot be achieved. The structure here refers to the chain structure of carbon black, and in the case of carbon black with a highly developed structure, it may not be possible to sufficiently disperse the average particle size during paint dispersion, even if the average particle size is 30 nm or less. This is because the actual particle size is much larger than this. The degree of structure of carbon black is usually expressed using the oil absorption amount per 100 g of carbon black using DBP, but if this value exceeds 250 ml, the object of the present invention cannot be achieved.
【０００９】またカーボンブラックを塗料中で高分子バ
インダーを用いて十分分散させ非磁性層の表面平滑性を
本発明の目的に合致したレベルにするためには、非磁性
粉体として平均粒径が３０ｎｍ以下でかつストラクチャ
ーがあまり発達していないカーボンブラックのみでは不
十分であり、無機フィラーをあわせて用いる必要がある
。
無機フィラーとしてはタルク，クレーのような天然物で
はなく、好ましくは微粒子で粒度の揃った合成品である
酸化鉄，酸化亜鉛，酸化アルミニウム，酸化チタンなど
の酸化物、炭酸カルシウム，炭酸マグネシウムなどの炭
酸塩、硫酸バリウム，硫酸ストロンチウムなどの硫酸塩
、窒化アルミニウムなどの窒化物、無水ケイ酸などのホ
ワイトカーボンなどが単独あるいは組み合わされて用い
られるが、もちろんこれらに限定されるものではない。
またその形状は粒状，板状，針状の粒子を用いることが
できる。その比率は非磁性粉体全体の５％以上必要であ
り、好ましくは１０〜９０％の範囲である。それ以上で
は磁気記録媒体全体の電気抵抗が大きくなりすぎる問題
点がある。非磁性塗料を作製するにあたりカーボンブラ
ックとともに無機フィラーをあわせて用いることで非磁
性層の表面平滑性が向上する理由は明確ではないが、分
散時塗料中で無機フィラーがカーボンブラックの分散の
分散媒体になっているとも考えられる。[0009] Furthermore, in order to sufficiently disperse carbon black in a paint using a polymer binder and to bring the surface smoothness of the non-magnetic layer to a level that meets the purpose of the present invention, the average particle size of the non-magnetic powder must be Carbon black with a diameter of 30 nm or less and a poorly developed structure is insufficient alone, and an inorganic filler must be used in combination. The inorganic filler is not a natural product such as talc or clay, but preferably a synthetic product with fine particles of uniform particle size, such as oxides such as iron oxide, zinc oxide, aluminum oxide, titanium oxide, calcium carbonate, magnesium carbonate, etc. Carbonates, sulfates such as barium sulfate and strontium sulfate, nitrides such as aluminum nitride, and white carbon such as silicic anhydride may be used alone or in combination, but are not limited to these. Moreover, the shape of particles can be granular, plate-like, or needle-like. The ratio thereof needs to be 5% or more of the total non-magnetic powder, preferably in the range of 10 to 90%. If it exceeds this range, there is a problem that the electrical resistance of the entire magnetic recording medium becomes too large. It is not clear why the surface smoothness of the non-magnetic layer is improved by using an inorganic filler together with carbon black when producing a non-magnetic paint, but the inorganic filler acts as a dispersion medium for dispersing carbon black in the paint during dispersion. It is also possible that it has become.
【００１０】高分子バインダーとしてはとくに限定され
るものではないが、たとえば水酸基，カルボキシル基，
アミノ基，スルフォン酸基，スルフォベタイン基などの
極性基を１種あるいは複数有する塩化ビニル系，ニトロ
セルロース系，ポリビニルブチラール系，ポリウレタン
系，ポリエステル系，ポリスチレン系，フェノキシ系、
アクリル系樹脂などの１種あるいは複数が用いられる。
非磁性粉体と高分子バインダーとの全体の中に占める非
磁性粉体の割合は重量で３０％以上、好ましくは３５％
以上であり、これ以下では非磁性層の表面平滑性が不十
分となる。また８５％以上になると、非磁性支持体への
接着性が不十分となる。The polymer binder is not particularly limited, but includes, for example, hydroxyl group, carboxyl group,
Vinyl chloride-based, nitrocellulose-based, polyvinyl butyral-based, polyurethane-based, polyester-based, polystyrene-based, phenoxy-based, which have one or more polar groups such as amino groups, sulfonic acid groups, and sulfobetaine groups;
One or more of acrylic resins are used. The proportion of the non-magnetic powder in the total of the non-magnetic powder and the polymer binder is 30% or more by weight, preferably 35%.
If it is less than this, the surface smoothness of the nonmagnetic layer will be insufficient. Moreover, if it exceeds 85%, the adhesion to the non-magnetic support becomes insufficient.
【００１１】潤滑剤としては、非磁性層の上に設ける磁
性層に用いているものと同じ系統の潤滑剤を用いること
が望ましく、通常はラウリン酸，ミリスチン酸，パルミ
チン酸，ステアリン酸などの飽和脂肪酸、オレイン酸，
リノール酸，リノレイン酸などの不飽和脂肪酸およびそ
れらと一価，二価および三価アルコールとのエステルの
１種あるいは複数が用いられる。それらの添加量は、脂
肪酸が上記非磁性粉体に対して０．５〜１０ｗｔ％望ま
しくは１〜５ｗｔ％、脂肪酸エステルが０．１〜１０ｗ
ｔ％望ましくは０．５〜５ｗｔ％である。As the lubricant, it is desirable to use the same type of lubricant as that used for the magnetic layer provided on the non-magnetic layer, and it is usually a saturated lubricant such as lauric acid, myristic acid, palmitic acid, or stearic acid. fatty acids, oleic acid,
One or more of unsaturated fatty acids such as linoleic acid and linoleic acid and esters of these fatty acids with monohydric, dihydric and trihydric alcohols are used. The amount of the fatty acid added is preferably 0.5 to 10 wt%, preferably 1 to 5 wt%, and the fatty acid ester is 0.1 to 10 wt% based on the non-magnetic powder.
t% is preferably 0.5 to 5 wt%.
【００１２】硬化剤としては、ポリイソシアネート化合
物などが適宜用いられる。また分散剤あるいはベンガラ
，アルミナ，酸化クロムなどの塗膜補強剤など従来公知
の添加剤も必要に応じて用いられる。[0012] As the curing agent, a polyisocyanate compound or the like is appropriately used. In addition, conventionally known additives such as dispersants or paint film reinforcing agents such as red iron oxide, alumina, and chromium oxide may be used as necessary.
【００１３】非磁性粉体と高分子バインダーおよび溶剤
を用いた塗料化にあってはボールミル，サンドミルなど
の公知の方法により、また必要に応じてはその前処理と
してニーダー、あるいはプラネタリーミキサーなどの方
法を適宜用いることができる。[0013] When making a coating using non-magnetic powder, a polymeric binder, and a solvent, a known method such as a ball mill or a sand mill may be used, and if necessary, a kneader or planetary mixer may be used as a pretreatment method. Any method can be used as appropriate.
【００１４】非磁性層の上に設けられる短波長記録にお
ける出力の高い磁性層に用いる磁性粉としては、従来公
知の保磁力が高く、粒子が極めて細かいメタル磁性粉，
バリウムフェライト粉などが好ましい。メタル磁性粉の
保磁力としては１１５ｋＡ／ｍ（１４４４Ｏｅ）以上、
粒子径は長軸長が０．３μｍ以下であることが必要であ
る。
またバリウムフェライト粉の場合、保磁力としては８０
ｋＡ／ｍ（１００５Ｏｅ）以上、粒子径は同じく０．３
μｍ以下であることが必要である。塗料化にあたって用
いられるバインダーは従来公知のバインダーが用いられ
るが、磁性粉が微粒子で分散しにくいことを考慮して分
散性に優れるバインダーを用いることが必要である。研
磨剤，潤滑剤なども公知のものが適宜用いられる。磁性
粉体と高分子バインダーおよび溶剤を用いた塗料化にあ
ってはボールミル，サンドミルなどの公知の方法により
、また必要に応じてはその前処理としてニーダー、ある
いはプラネタリーミキサーなどの方法を適宜用いること
ができる。As the magnetic powder used for the magnetic layer with high output in short wavelength recording provided on the nonmagnetic layer, conventionally known metal magnetic powders with high coercive force and extremely fine particles,
Preferred is barium ferrite powder. The coercive force of metal magnetic powder is 115 kA/m (1444 Oe) or more,
The particle size requires that the major axis length is 0.3 μm or less. In addition, in the case of barium ferrite powder, the coercive force is 80
kA/m (1005 Oe) or more, particle size is also 0.3
It is necessary that the thickness be less than μm. Conventionally known binders are used as the binder for making the paint, but it is necessary to use a binder with excellent dispersibility considering that the magnetic powder is fine particles and difficult to disperse. Known abrasives, lubricants, etc. may be used as appropriate. When making a coating using magnetic powder, a polymeric binder, and a solvent, a known method such as a ball mill or a sand mill is used, and if necessary, a kneader or planetary mixer is used as a pretreatment method. be able to.
【００１５】非磁性支持体としてはとくに限定はないが
、通常のポリエチレンテレフタレート，ポリエチレンナ
フタレート，ポリサルフォン，アラミドなどの表面平滑
性と機械的強度，寸法安定性に優れる支持体が用いられ
る。The nonmagnetic support is not particularly limited, but supports having excellent surface smoothness, mechanical strength, and dimensional stability such as ordinary polyethylene terephthalate, polyethylene naphthalate, polysulfone, and aramid are used.
【００１６】非磁性支持体上に非磁性層とさらにその上
に磁性層を設ける方法としては、非磁性層を塗布乾燥後
磁性層を塗布乾燥する方法あるいは非磁性層を塗布し乾
燥する前に磁性層を塗布乾燥する方法どちらでも用いる
ことができる。非磁性層あるいは磁性層を塗布する方法
としては、グラビヤロールコーター，リバースロールコ
ーター，ダイコーターなどの方法を用いることができる
。以上のような非磁性支持体上に非磁性層とさらにその
上に磁性層を設けた磁気記録媒体を作製するにはたとえ
ば非磁性支持体上に非磁性層とさらにその上に磁性層を
設けたのち、カレンダー処理などの所定の表面処理を施
してまた必要ならば各種環境条件下での保存処理を行い
所定の大きさに裁断すればよい。またテープの走行性向
上のため、非磁性支持体の非磁性層および磁性層の反対
側に表面が平滑で摩擦係数の小さいバックコート層を設
けてもよい。Methods for providing a nonmagnetic layer on a nonmagnetic support and a magnetic layer thereon include a method in which the nonmagnetic layer is coated and dried, and then a magnetic layer is coated and dried, or a method in which the nonmagnetic layer is coated and dried before it is dried. Any method of applying and drying the magnetic layer can be used. As a method for applying the nonmagnetic layer or the magnetic layer, methods such as a gravure roll coater, a reverse roll coater, and a die coater can be used. To produce a magnetic recording medium in which a nonmagnetic layer is provided on a nonmagnetic support and a magnetic layer is further provided on the nonmagnetic support, for example, a nonmagnetic layer is provided on the nonmagnetic support and a magnetic layer is further provided on the nonmagnetic support. Thereafter, it may be subjected to a predetermined surface treatment such as calendering, and if necessary, subjected to storage treatment under various environmental conditions, and then cut into a predetermined size. Further, in order to improve the running properties of the tape, a back coat layer having a smooth surface and a small coefficient of friction may be provided on the opposite side of the nonmagnetic layer and the magnetic layer of the nonmagnetic support.
【００１７】磁性層の膜厚は０．２〜２μｍであること
が望ましい。The thickness of the magnetic layer is preferably 0.2 to 2 μm.
【００１８】[0018]
【作用】磁気記録媒体の構成を上述の通りとすることで
、磁性層の膜厚は薄く厚み損失を少なくして短波長記録
における媒体の出力を向上させ、かつ非磁性支持体上の
非磁性層および磁性層の全体の厚みは従来の磁気記録媒
体の構成とほぼ同じとなり磁性層表層部分に対する潤滑
剤の補給も十分なされて信頼性，耐久性も向上させるこ
とができる。[Function] By configuring the magnetic recording medium as described above, the thickness of the magnetic layer is thin and thickness loss is reduced, improving the output of the medium in short wavelength recording, and the non-magnetic layer on the non-magnetic support The overall thickness of the magnetic layer and the magnetic layer is approximately the same as that of a conventional magnetic recording medium, and sufficient lubricant is supplied to the surface layer of the magnetic layer, thereby improving reliability and durability.
【００１９】[0019]
【実施例】以下、本発明を実施例により詳しく説明する
。[Examples] The present invention will be explained in detail below using examples.
【００２０】実施例１
非磁性塗料としては、サンドミルを用いて（表１）の組
成の塗料を作製した。以下、部とあるのは重量部のこと
である。Example 1 A non-magnetic paint having the composition shown in Table 1 was prepared using a sand mill. Hereinafter, parts refer to parts by weight.
【００２１】[0021]
【表１】[Table 1]
【００２２】磁性塗料としては、サンドミルを用いて（
表２）の組成の塗料を作製した。以下、部とあるのは重
量部のことである。[0022] As the magnetic paint, use a sand mill (
A paint having the composition shown in Table 2) was prepared. Hereinafter, parts refer to parts by weight.
【００２３】[0023]
【表２】[Table 2]
【００２４】膜厚６μｍ、非磁性層および磁性層塗布側
の表面粗度（Ｒａ）５ｎｍその反対側の表面粗度２０ｎ
ｍのスーパーテンシャライズドポリエチレンテレフタレ
ートベースフィルム上に上記非磁性塗料を乾燥後の膜厚
が２μｍになるように塗布後乾燥前にその上に上記磁性
塗料を乾燥後の膜厚が０．５μｍになるように塗布磁場
配向後乾燥しカレンダーによる表面処理後スリッティン
グして供試テープとした。Film thickness: 6 μm, surface roughness (Ra) of the nonmagnetic layer and magnetic layer coating side: 5 nm, surface roughness of the opposite side: 20 nm
After applying the above-mentioned non-magnetic paint on a super-tensioned polyethylene terephthalate base film of 300 m to a dry film thickness of 2 μm, apply the above-mentioned magnetic paint on top of it before drying so that the dry film thickness is 0.5 μm. The tape was coated and oriented in a magnetic field, dried, and surface treated with a calendar, followed by slitting to obtain a test tape.
【００２５】実施例２
非磁性塗料として実施例１の組成の中で硫酸バリウムの
代わりに平均粒径４０ｎｍ炭酸カルシウムを用いた以外
は実施例１と同様に非磁性塗料を作製した。Example 2 A non-magnetic paint was prepared in the same manner as in Example 1 except that calcium carbonate having an average particle size of 40 nm was used in place of barium sulfate in the composition of Example 1.
【００２６】
上記以外は実施例１と同様にテープを作製した。
実施例３
磁性塗料として実施例１の組成の中でメタル粉の代わり
に平均粒径０．１μｍ板状比６ Ｈｃ＝１００ｋＡ／
ｍのバリウムフェライト粉を用いた以外は実施例１と同
様に磁性塗料を作製した。A tape was produced in the same manner as in Example 1 except for the above. Example 3 As a magnetic paint, in the composition of Example 1, instead of metal powder, an average particle size of 0.1 μm and a plate ratio of 6 Hc = 100 kA/
A magnetic paint was produced in the same manner as in Example 1 except that barium ferrite powder of m was used.
【００２７】
上記以外は実施例１と同様にテープを作製した。
実施例４
非磁性塗料として実施例１の組成の中で硫酸バリウムの
代わりに平均粒径４０ｎｍ炭酸カルシウムを用いた以外
は実施例１と同様に非磁性塗料を作製した。A tape was produced in the same manner as in Example 1 except for the above. Example 4 A non-magnetic paint was produced in the same manner as in Example 1, except that calcium carbonate having an average particle size of 40 nm was used in place of barium sulfate in the composition of Example 1 as the non-magnetic paint.
【００２８】
上記以外は実施例３と同様にテープを作製した。
実施例５
磁性塗料の乾燥後の膜厚が１．５μｍになるように塗布
した以外は実施例１と同様にテープを作製した。A tape was produced in the same manner as in Example 3 except for the above. Example 5 A tape was produced in the same manner as in Example 1, except that the magnetic paint was applied so that the film thickness after drying was 1.5 μm.
【００２９】実施例６
磁性塗料の乾燥後の膜厚が１．５μｍになるように塗布
した以外は実施例３と同様にテープを作製した。Example 6 A tape was produced in the same manner as in Example 3, except that the magnetic paint was applied so that the film thickness after drying was 1.5 μm.
【００３０】実施例７
非磁性塗料の組成としてカーボンブラックを７０部硫酸
バリウムを３０部とした以外は実施例１と同様にテープ
を作製した。Example 7 A tape was produced in the same manner as in Example 1, except that the composition of the non-magnetic paint was 70 parts of carbon black and 30 parts of barium sulfate.
【００３１】比較例１
非磁性塗料を用いず、直接磁性塗料をベースフィルム上
に塗布した以外は実施例１と同様にテープを作製した。Comparative Example 1 A tape was produced in the same manner as in Example 1, except that the magnetic paint was applied directly onto the base film without using the non-magnetic paint.
【００３２】比較例２
非磁性塗料を用いず、直接磁性塗料をベースフィルム上
に塗布した以外は実施例３と同様にテープを作製した。Comparative Example 2 A tape was produced in the same manner as in Example 3, except that the magnetic paint was applied directly onto the base film without using the non-magnetic paint.
【００３３】比較例３
非磁性塗料を用いず、磁性塗料の乾燥後の膜厚が４μｍ
になるように直接磁性塗料をベースフィルム上に塗布し
た以外は実施例１と同様にテープを作製した。Comparative Example 3 No non-magnetic paint was used, and the film thickness after drying of the magnetic paint was 4 μm.
A tape was produced in the same manner as in Example 1, except that the magnetic paint was applied directly onto the base film so that the magnetic paint was applied directly onto the base film.
【００３４】比較例４
非磁性塗料を用いず、磁性塗料の乾燥後の膜厚が４μｍ
になるように直接磁性塗料をベースフィルム上に塗布し
た以外は実施例３と同様にテープを作製した。Comparative Example 4 No non-magnetic paint was used, and the film thickness after drying of the magnetic paint was 4 μm.
A tape was produced in the same manner as in Example 3, except that the magnetic paint was applied directly onto the base film so that the magnetic paint was applied directly onto the base film.
【００３５】比較例５
非磁性塗料のカーボンブラックとして実施例１で用いた
ものに代えて平均粒径４０ｎｍのものを用いた以外は実
施例１と同様にテープを作製した。Comparative Example 5 A tape was produced in the same manner as in Example 1, except that carbon black with an average particle diameter of 40 nm was used in place of the carbon black used in Example 1 as the non-magnetic paint.
【００３６】比較例６
非磁性塗料のカーボンブラックとして実施例１で用いた
ものに代えて平均粒径１６ｎｍ吸油量３００ｍｌのもの
を用いた以外は実施例１と同様にテープを作製した。Comparative Example 6 A tape was produced in the same manner as in Example 1, except that carbon black for the non-magnetic paint used in Example 1 was replaced with carbon black having an average particle size of 16 nm and an oil absorption of 300 ml.
【００３７】比較例７
非磁性塗料の組成として硫酸バリウムを用いずカーボン
ブラックを１００部とした以外は実施例１と同様にテー
プを作製した。Comparative Example 7 A tape was produced in the same manner as in Example 1, except that barium sulfate was not used and carbon black was used at 100 parts as the composition of the non-magnetic paint.
【００３８】実施例１〜７および比較例１〜７の１４種
類のテープにつき、電磁変換特性および信頼性，耐久性
，表面粗度を測定した結果を（表３）に示した。測定条
件は（表４）の通りである。The electromagnetic conversion characteristics, reliability, durability, and surface roughness of 14 types of tapes of Examples 1 to 7 and Comparative Examples 1 to 7 were measured, and the results are shown in Table 3. The measurement conditions are as shown in (Table 4).
【００３９】[0039]
【表３】[Table 3]
【００４０】[0040]
【表４】[Table 4]
【００４１】[0041]
【発明の効果】以上のように本発明は、非磁性支持体上
に非磁性層とさらにその上に磁性層を設けてなる磁気記
録媒体において、該非磁性層中に平均粒径３０ｎｍ以下
でかつトラクチャーがあまり発達していないカーボンブ
ラックと無機フィラーとを含むことにより、短波長記録
において出力が高く信頼性，耐久性に優れた磁気記録媒
体を実現するものである。As described above, the present invention provides a magnetic recording medium in which a nonmagnetic layer is provided on a nonmagnetic support and a magnetic layer is further provided on the nonmagnetic support. By containing carbon black whose structure is not very developed and an inorganic filler, a magnetic recording medium with high output in short wavelength recording and excellent reliability and durability is realized.
Claims (1)
に磁性層を設けてなる磁気記録媒体において、該非磁性
層中に平均粒径３０ｎｍ以下でかつストラクチャーがあ
まり発達していないカーボンブラックと無機フィラーと
を含むことを特徴とする磁気記録媒体。1. A magnetic recording medium comprising a nonmagnetic layer on a nonmagnetic support and a magnetic layer thereon, wherein the nonmagnetic layer contains carbon having an average grain size of 30 nm or less and having a poorly developed structure. A magnetic recording medium characterized by containing black and an inorganic filler.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3151390A JPH04372712A (en) | 1991-06-24 | 1991-06-24 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP3151390A JPH04372712A (en) | 1991-06-24 | 1991-06-24 | Magnetic recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH04372712A true JPH04372712A (en) | 1992-12-25 |
Family
ID=15517539
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP3151390A Pending JPH04372712A (en) | 1991-06-24 | 1991-06-24 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH04372712A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004046035A3 (en) * | 2002-11-21 | 2005-01-13 | Nanosolutions Gmbh | Method for producing alkaline earth sulphate nanoparticles |
| JP2021127288A (en) * | 2017-08-11 | 2021-09-02 | 東洋アルミニウム株式会社 | Aluminum nitride-based filler |
-
1991
- 1991-06-24 JP JP3151390A patent/JPH04372712A/en active Pending
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO2004046035A3 (en) * | 2002-11-21 | 2005-01-13 | Nanosolutions Gmbh | Method for producing alkaline earth sulphate nanoparticles |
| US7288239B2 (en) * | 2002-11-21 | 2007-10-30 | Nanosolutions Gmbh | Method for producing alkaline earth sulphate nanoparticles |
| CN100354207C (en) * | 2002-11-21 | 2007-12-12 | 纳米技术应用中心（Can）股份有限公司 | Method for producing alkaline earth sulphate nanoparticles |
| JP2021127288A (en) * | 2017-08-11 | 2021-09-02 | 東洋アルミニウム株式会社 | Aluminum nitride-based filler |
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