JPH05159279A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPH05159279A JPH05159279A JP34963991A JP34963991A JPH05159279A JP H05159279 A JPH05159279 A JP H05159279A JP 34963991 A JP34963991 A JP 34963991A JP 34963991 A JP34963991 A JP 34963991A JP H05159279 A JPH05159279 A JP H05159279A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- group
- dispersant
- powder
- magnetic powder
- 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.)
- Withdrawn
Links
- 239000006247 magnetic powder Substances 0.000 claims abstract description 31
- 239000002270 dispersing agent Substances 0.000 claims abstract description 22
- 125000002887 hydroxy group Chemical group [H]O* 0.000 claims abstract description 13
- 125000003277 amino group Chemical group 0.000 claims abstract description 12
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical group OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 claims abstract description 11
- 125000001174 sulfone group Chemical group 0.000 claims abstract description 11
- 238000006243 chemical reaction Methods 0.000 abstract description 6
- 239000000843 powder Substances 0.000 description 12
- 229920005989 resin Polymers 0.000 description 7
- 239000011347 resin Substances 0.000 description 7
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 239000011230 binding agent Substances 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 239000003973 paint Substances 0.000 description 5
- 230000000052 comparative effect Effects 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 239000000203 mixture Substances 0.000 description 4
- 230000003746 surface roughness Effects 0.000 description 4
- 229920002554 vinyl polymer Polymers 0.000 description 4
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- ZMXDDKWLCZADIW-UHFFFAOYSA-N N,N-Dimethylformamide Chemical compound CN(C)C=O ZMXDDKWLCZADIW-UHFFFAOYSA-N 0.000 description 3
- 229920001577 copolymer Polymers 0.000 description 3
- -1 fatty acid Low molecular weight compounds Chemical class 0.000 description 3
- 239000012948 isocyanate Substances 0.000 description 3
- 230000005415 magnetization Effects 0.000 description 3
- 239000003960 organic solvent Substances 0.000 description 3
- 229920006267 polyester film Polymers 0.000 description 3
- 229910000859 α-Fe Inorganic materials 0.000 description 3
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 229920002433 Vinyl chloride-vinyl acetate copolymer Polymers 0.000 description 2
- 229910001566 austenite Inorganic materials 0.000 description 2
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 2
- 235000014113 dietary fatty acids Nutrition 0.000 description 2
- 238000001035 drying Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 229930195729 fatty acid Natural products 0.000 description 2
- 239000000194 fatty acid Substances 0.000 description 2
- 238000009499 grossing Methods 0.000 description 2
- 239000002184 metal Substances 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229920005749 polyurethane resin Polymers 0.000 description 2
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 2
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- TWJNQYPJQDRXPH-UHFFFAOYSA-N 2-cyanobenzohydrazide Chemical compound NNC(=O)C1=CC=CC=C1C#N TWJNQYPJQDRXPH-UHFFFAOYSA-N 0.000 description 1
- 102000009123 Fibrin Human genes 0.000 description 1
- 108010073385 Fibrin Proteins 0.000 description 1
- BWGVNKXGVNDBDI-UHFFFAOYSA-N Fibrin monomer Chemical compound CNC(=O)CNC(=O)CN BWGVNKXGVNDBDI-UHFFFAOYSA-N 0.000 description 1
- NTIZESTWPVYFNL-UHFFFAOYSA-N Methyl isobutyl ketone Chemical compound CC(C)CC(C)=O NTIZESTWPVYFNL-UHFFFAOYSA-N 0.000 description 1
- UIHCLUNTQKBZGK-UHFFFAOYSA-N Methyl isobutyl ketone Natural products CCC(C)C(C)=O UIHCLUNTQKBZGK-UHFFFAOYSA-N 0.000 description 1
- 235000021360 Myristic acid Nutrition 0.000 description 1
- TUNFSRHWOTWDNC-UHFFFAOYSA-N Myristic acid Natural products CCCCCCCCCCCCCC(O)=O TUNFSRHWOTWDNC-UHFFFAOYSA-N 0.000 description 1
- 229910018487 Ni—Cr Inorganic materials 0.000 description 1
- 239000003082 abrasive agent Substances 0.000 description 1
- 239000000654 additive Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 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
- 239000002216 antistatic agent Substances 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- HGAZMNJKRQFZKS-UHFFFAOYSA-N chloroethene;ethenyl acetate Chemical compound ClC=C.CC(=O)OC=C HGAZMNJKRQFZKS-UHFFFAOYSA-N 0.000 description 1
- 239000008199 coating composition Substances 0.000 description 1
- 229940126214 compound 3 Drugs 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 150000004665 fatty acids Chemical class 0.000 description 1
- 229950003499 fibrin Drugs 0.000 description 1
- 230000001771 impaired effect Effects 0.000 description 1
- 150000002513 isocyanates Chemical class 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 125000002467 phosphate group Chemical group [H]OP(=O)(O[H])O[*] 0.000 description 1
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
Landscapes
- Paints Or Removers (AREA)
- Magnetic Record Carriers (AREA)
Abstract
Description
【０００１】[0001]
【産業上の利用分野】この発明は磁気記録媒体に関し、
さらに詳しくは、磁性粉末の分散性が良好で電磁変換特
性および耐久性に優れた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 magnetic recording medium,
More specifically, the present invention relates to a magnetic recording medium having excellent dispersibility of magnetic powder and excellent electromagnetic conversion characteristics and durability.
【０００２】[0002]
【従来の技術】磁気記録媒体は、通常、磁性粉末、結合
剤成分、有機溶剤およびその他の必要成分からなる磁性
塗料をポリエステルフィルムなどの基体上に塗布、乾燥
してつくられ、磁性粉末の分散性が良好で電磁変換特性
に優れるとともに、機械的特性が良好で耐久性に優れて
いることが要求される。このため、磁性粉末の分散性を
改善する方法として、分子量が約３００００の塩化ビニ
ル−酢酸ビニル共重合体を使用することが行われており
（特開平１−１００７２７号）、また、脂肪酸などの低
分子量化合物は磁性粉末の分散性を良好にすることが知
られている。（特開平１−１９９３１６号）2. Description of the Related Art A magnetic recording medium is usually prepared by coating a base material such as a polyester film with a magnetic paint comprising a magnetic powder, a binder component, an organic solvent and other necessary components and drying the magnetic powder to disperse the magnetic powder. It is required to have good properties and excellent electromagnetic conversion characteristics as well as good mechanical characteristics and excellent durability. Therefore, as a method of improving the dispersibility of the magnetic powder, a vinyl chloride-vinyl acetate copolymer having a molecular weight of about 30,000 has been used (Japanese Patent Laid-Open No. 1007127), and also fatty acid Low molecular weight compounds are known to improve the dispersibility of magnetic powder. (JP-A-1-199316)
【０００３】[0003]
【発明が解決しようとする課題】ところが、分子量が約
３００００の塩化ビニル−酢酸ビニル共重合体は分子量
が大きいため、磁性粉末の分散性を未だ充分に向上させ
ることができず、脂肪酸などの低分子量化合物では、磁
性粉末の分散性は改善されても磁性層の機械的強度が低
下して耐久性が損なわれるという難点がある。However, since the vinyl chloride-vinyl acetate copolymer having a molecular weight of about 30,000 has a large molecular weight, the dispersibility of the magnetic powder cannot be sufficiently improved and the content of fatty acids and the like is low. The molecular weight compound has a drawback that the mechanical strength of the magnetic layer is lowered and the durability is impaired even though the dispersibility of the magnetic powder is improved.
【０００４】[0004]
【課題を解決するための手段】この発明は、かかる現状
に鑑み種々検討を行った結果なされたもので、磁性粉末
の分散剤として、スルホン基、リン酸基、アミノ基およ
び水酸基から選ばれる少なくとも２以上の極性基を有す
る分子量が１００００以下の多官能基分散剤を使用する
ことによって、磁性粉末の分散性を充分に向上させ、磁
性層の表面平滑性を良好にして、電磁変換特性および耐
久性を一段と向上させたものである。SUMMARY OF THE INVENTION The present invention has been made as a result of various studies in view of the present circumstances, and as a dispersant for magnetic powders, at least one selected from a sulfone group, a phosphate group, an amino group and a hydroxyl group. By using a polyfunctional dispersant having 2 or more polar groups and a molecular weight of 10,000 or less, the dispersibility of the magnetic powder is sufficiently improved, the surface smoothness of the magnetic layer is improved, and the electromagnetic conversion characteristics and durability are improved. It has improved the sex.
【０００５】この発明において、磁性粉末の分散剤とし
て使用する多官能基分散剤は、分子量が１００００以下
で、スルホン基、リン酸基、アミノ基および水酸基から
選ばれる少なくとも２以上の極性基を有しているため、
磁性粉末との親和性に優れ、スルホン基、リン酸基、ア
ミノ基および水酸基などの極性基が磁性粉末の粒子表面
に強固に結合する。従って、この種のスルホン基、リン
酸基、アミノ基および水酸基から選ばれる少なくとも２
以上の極性基を有する分子量が１００００以下の多官能
基分散剤を、磁性粉末の分散剤として使用すると、磁性
粉末の分散性が充分に向上され、磁性層の表面平滑性が
良好になって、高出力が得られる。In the present invention, the polyfunctional dispersant used as the dispersant for the magnetic powder has a molecular weight of 10,000 or less and has at least two polar groups selected from sulfone groups, phosphoric acid groups, amino groups and hydroxyl groups. Because
It has excellent affinity with magnetic powder, and polar groups such as sulfone groups, phosphoric acid groups, amino groups and hydroxyl groups are firmly bonded to the particle surface of magnetic powder. Therefore, at least 2 selected from this type of sulfone group, phosphoric acid group, amino group and hydroxyl group.
When a polyfunctional dispersant having a polar group and a molecular weight of 10,000 or less is used as a dispersant for the magnetic powder, the dispersibility of the magnetic powder is sufficiently improved, and the surface smoothness of the magnetic layer is improved. High output can be obtained.
【０００６】また、この種の多官能基分散剤は結合剤樹
脂との相溶性もよく、磁性粉末の粒子表面に強固に結合
したこの種の多官能基分散剤を介して結合剤樹脂が磁性
粉末と結合し、さらに水酸基などの極性基はイソシアネ
−ト化合物などの硬化剤と良好に反応する。従って、こ
の種のスルホン基、リン酸基、アミノ基および水酸基か
ら選ばれる少なくとも２以上の極性基を有する分子量が
１００００以下の多官能基分散剤を、磁性粉末の分散剤
として使用すると、磁性粉末の分散性が充分に改善さ
れ、電磁変換特性が充分に向上されるとともに、磁性層
の機械的強度が改善され、耐久性が向上される。Further, this kind of polyfunctional dispersant has a good compatibility with the binder resin, and the binder resin is magnetic through the polyfunctional dispersant of this kind firmly bonded to the particle surface of the magnetic powder. It binds to the powder, and polar groups such as hydroxyl groups react well with curing agents such as isocyanate compounds. Therefore, when a polyfunctional dispersant having at least two polar groups selected from sulfone groups, phosphoric acid groups, amino groups and hydroxyl groups and having a molecular weight of 10,000 or less is used as a dispersant for the magnetic powder, the magnetic powder Is sufficiently improved, the electromagnetic conversion characteristics are sufficiently improved, the mechanical strength of the magnetic layer is improved, and the durability is improved.
【０００７】このようなスルホン基、リン酸基、アミノ
基および水酸基から選ばれる少なくとも２以上の極性基
を有する多官能基分散剤は、分子量が１００００より大
きいと分散性の向上効果が充分に発揮されず、また粘度
上昇の恐れがあるため分子量１００００以下のものが好
ましく使用され、具体例としては、たとえば、ＩＣＩ社
製；ハイパ−マ−ＬＰ−８などが好適なものとして使用
される。使用量は磁性粉末に対して 0.5重量％より少な
いと所期の効果が得られず、2.0 重量％より多くすると
余分な分散剤が磁性層中に存在し、耐久性に悪影響を及
ぼすため、 0.5〜2.0 重量％の範囲内で使用するのが好
ましい。The polyfunctional group dispersant having at least two polar groups selected from the sulfone group, the phosphoric acid group, the amino group and the hydroxyl group exhibits a sufficient dispersibility-improving effect when the molecular weight is more than 10,000. However, those having a molecular weight of 10,000 or less are preferably used because they may not increase in viscosity, and specific examples thereof include those manufactured by ICI; Hypermer-LP-8 and the like. If the amount used is less than 0.5% by weight based on the magnetic powder, the desired effect will not be obtained, and if it is more than 2.0% by weight, excess dispersant will be present in the magnetic layer, adversely affecting durability. It is preferably used in the range of up to 2.0% by weight.
【０００８】この発明の磁気記録媒体を製造するには常
法に準じて行えばよく、たとえば、前記のスルホン基、
リン酸基、アミノ基および水酸基から選ばれる少なくと
も２以上の極性基を有する多官能基分散剤を、磁性粉
末、結合剤樹脂、有機溶剤およびその他の必要成分とと
もに混合分散して磁性塗料を調製し、この磁性塗料をポ
リエステルフィルムなどの基体上に、吹きつけもしくは
ロ−ル塗りなどの任意の方法で塗布し、乾燥すればよ
い。The magnetic recording medium of the present invention may be manufactured according to a conventional method. For example, the above-mentioned sulfone group,
A magnetic paint is prepared by mixing and dispersing a polyfunctional group dispersant having at least two polar groups selected from phosphoric acid group, amino group and hydroxyl group together with magnetic powder, binder resin, organic solvent and other necessary components. The magnetic paint may be applied onto a substrate such as a polyester film by an arbitrary method such as spraying or roll coating, and dried.
【０００９】ここで、磁性粉末としては、γ−Ｆｅ2 Ｏ
3 粉末、Ｆｅ3 Ｏ4 粉末、Ｃｏ含有γ−Ｆｅ2 Ｏ3 粉
末、Ｃｏ含有Ｆｅ3 Ｏ4 粉末、ＣｒＯ2 粉末などの酸化
物粉末、Ｆｅ粉末、Ｃｏ粉末、Ｆｅ−Ｎｉ−Ｃｒ合金粉
末などの金属粉末など、従来公知の各種磁性粉末が広く
包含されるが、特に、金属粉末の分散性が一段と向上さ
れる。Here, as the magnetic powder, γ-Fe 2 O is used.
3 powder, Fe 3 O 4 powder, Co-containing γ-Fe 2 O 3 powder, Co-containing Fe 3 O 4 powder, oxide powder such as CrO 2 powder, Fe powder, Co powder, Fe-Ni-Cr alloy powder, etc. Various conventionally known magnetic powders such as the above metal powder are widely included, but in particular, the dispersibility of the metal powder is further improved.
【００１０】また、結合剤樹脂としては、塩化ビニル−
酢酸ビニル系共重合体、ポリビニルブチラ−ル系樹脂、
繊維素系樹脂、ポリウレタン系樹脂、ポリエステル系樹
脂、イソシアネ−ト化合物など、磁気記録媒体に通常使
用される結合剤樹脂がいずれも好適に使用される。Further, as the binder resin, vinyl chloride-
Vinyl acetate-based copolymer, polyvinyl butyral-based resin,
Any binder resin usually used for magnetic recording media, such as fibrin resin, polyurethane resin, polyester resin, and isocyanate compound, is preferably used.
【００１１】さらに、有機溶剤としては、メチルイソブ
チルケトン、メチルエチルケトン、シクロヘキサノン、
トルエン、酢酸エチル、テトラヒドロフラン、ジオキサ
ン、ジメチルホルムアミドなど、一般に磁気記録媒体に
使用されるものが単独もしくは二種以上混合して使用さ
れる。Further, as the organic solvent, methyl isobutyl ketone, methyl ethyl ketone, cyclohexanone,
Toluene, ethyl acetate, tetrahydrofuran, dioxane, dimethylformamide and the like which are generally used in magnetic recording media are used alone or in admixture of two or more.
【００１２】なお、磁性塗料中には、通常使用されてい
る各種添加剤、たとえば、潤滑剤、研磨剤、帯電防止剤
などを任意に添加使用してもよい。In the magnetic coating composition, various commonly used additives such as lubricants, abrasives and antistatic agents may be optionally added and used.
【００１３】[0013]
【実施例】次に、この発明の実施例について説明する。 実施例１ α−Ｆｅ磁性粉末（ＢＥＴ比表面積４５ｍ2 /g、保磁力１ ３００重量部 ５００エルステッド、飽和磁化１２０ emu/g） 塩化ビニル−酢酸ビニル−ビニルアルコ−ル共重合体 ３０ 〃 （米国 U.C.C社製；ＶＡＧＨ） ポリウレタン樹脂（日本ポリウレタン工業社製；Ｎ−２３ １０ 〃 ０１） 三官能性低分子量イソシアネ−ト化合物 ３ 〃 多官能基分散剤（ＩＣＩ社製；ハイパ−マ−ＬＰ−８、ス ３ 〃 ルホン基，リン酸基，アミノ基，水酸基含有） カ−ボンブラック ９ 〃 アルミナ ２０ 〃 ミリスチン酸 ４ 〃 メチルエチルケトン ３００ 〃 トルエン ３００ 〃 この組成物をボ−ルミル中で９６時間混合分散して磁性
塗料を調製し、この磁性塗料を厚さ１３μｍのポリエス
テルフィルム上に、乾燥後の厚さが３μｍとなるように
塗布、乾燥して磁性層を形成し、平滑化処理後、所定の
幅に裁断して磁気テ−プをつくった。EXAMPLES Next, examples of the present invention will be described. Example 1 α-Fe magnetic powder (BET specific surface area 45 m 2 / g, coercive force 1 300 parts by weight 500 oersted, saturation magnetization 120 emu / g) vinyl chloride-vinyl acetate-vinyl alcohol copolymer 30 〃 (US UCC Manufactured by VAGH) Polyurethane resin (manufactured by Nippon Polyurethane Industry Co., Ltd .; N-23 10 〃 01) Trifunctional low molecular weight isocyanate compound 3 〃 Polyfunctional dispersant (manufactured by ICI; Hypermer LP-8, Soluene group, phosphoric acid group, amino group, and hydroxyl group) Carbon black 9〃 Alumina 20〃 Myristic acid 4〃 Methyl ethyl ketone 300〃 Toluene 300〃 This composition is mixed and dispersed in a ball mill for 96 hours. A magnetic paint is prepared, and this magnetic paint is applied onto a polyester film having a thickness of 13 μm so that the thickness after drying becomes 3 μm, and dried. Then, a magnetic layer was formed, smoothed, and then cut into a predetermined width to form a magnetic tape.
【００１４】実施例２ 実施例１における磁性塗料の組成において、ＢＥＴ比表
面積が４５ｍ2 /g、保磁力が１５００エルステッド、飽
和磁化が１２０ emu/gのα−Ｆｅ磁性粉末に代えて、Ｂ
ＥＴ比表面積が５５ｍ2 /g、保磁力が１６００エルステ
ッド、飽和磁化が１２５ emu/gのα−Ｆｅ磁性粉末を同
量使用し、塩化ビニル−酢酸ビニル−ビニルアルコ−ル
共重合体の使用量を３０重量部から４０重量部に変更
し、さらに、多官能基分散剤の使用量を３重量部から６
重量部に変更した以外は、実施例１と同様にして磁気テ
−プをつくった。Example 2 In the composition of the magnetic coating material of Example 1, B-specific surface area was 45 m 2 / g, coercive force was 1500 oersted, and saturation magnetization was 120 emu / g in place of α-Fe magnetic powder.
Using the same amount of α-Fe magnetic powder with an ET specific surface area of 55 m 2 / g, coercive force of 1600 oersted and saturation magnetization of 125 emu / g, the amount of vinyl chloride-vinyl acetate-vinyl alcohol copolymer used was Changed from 30 parts by weight to 40 parts by weight, and changed the amount of polyfunctional dispersant used from 3 parts by weight to 6 parts by weight.
A magnetic tape was produced in the same manner as in Example 1 except that the weight part was changed.
【００１５】比較例１ 実施例１における磁性塗料の組成において、多官能基分
散剤を省いた以外は、実施例１と同様にして磁気テ−プ
をつくった。Comparative Example 1 A magnetic tape was prepared in the same manner as in Example 1 except that the polyfunctional dispersant was omitted from the composition of the magnetic coating material in Example 1.
【００１６】比較例２ 実施例２における磁性塗料の組成において、多官能基分
散剤を省いた以外は、実施例２と同様にして磁気テ−プ
をつくった。Comparative Example 2 A magnetic tape was prepared in the same manner as in Example 2 except that the polyfunctional dispersant was omitted from the composition of the magnetic coating material in Example 2.
【００１７】各実施例および比較例で得られた磁気テ−
プについて、平滑化処理前後の磁性層の表面粗さを測定
し、ＲＦ出力および耐久性を調べた。磁性層の表面粗さ
は、東京精密社製；ＳＵＲＦＣＯＭ触針式表面粗さ計
（直径 0.2μｍ）を使用して測定した。またＲＦ出力
は、５０％ホワイト信号を入力し、再生時の出力信号の
電圧を測定してリファレンステ−プと比べた。さらに耐
久性は、−５℃におけるスチルライフ（初期出力から６
ｄＢ低下するまでの時間）を測定して調べた。下記表１
はその結果である。The magnetic tape obtained in each Example and Comparative Example
The surface roughness of the magnetic layer before and after the smoothing treatment was measured, and the RF output and durability were examined. The surface roughness of the magnetic layer was measured using a SURFCOM stylus type surface roughness meter (diameter 0.2 μm) manufactured by Tokyo Seimitsu Co., Ltd. As the RF output, a 50% white signal was input, and the voltage of the output signal during reproduction was measured and compared with a reference tape. Furthermore, durability is still life at -5 ℃ (from the initial output 6
The time until a decrease in dB) was measured and examined. Table 1 below
Is the result.
【００１８】 [0018]
【００１９】[0019]
【発明の効果】上記表１から明らかなように、実施例１
および２で得られた磁気テ−プは、比較例１および２で
得られた磁気テ−プに比し、いずれも平滑化処理前後の
磁性層の表面粗さが小さく、またＲＦ出力が高くて、耐
久性がよく、このことからこの発明によって得られる磁
気記録媒体は、磁性粉末の分散性が良好で、電磁変換特
性に優れ、耐久性も一段と向上されていることがわか
る。As is apparent from Table 1 above, Example 1
Compared with the magnetic tapes obtained in Comparative Examples 1 and 2, the magnetic tapes obtained in Examples 1 and 2 had small surface roughness of the magnetic layer before and after the smoothing treatment, and had high RF output. Therefore, it is understood that the magnetic recording medium obtained by the present invention has good dispersibility of the magnetic powder, excellent electromagnetic conversion characteristics, and further improved durability.
Claims (2)
水酸基から選ばれる少なくとも２以上の極性基を有する
分子量が１００００以下の多官能基分散剤を、磁性粉末
とともに含んでなる磁性層を有する磁気記録媒体1. A magnetic layer having a magnetic layer containing a polyfunctional dispersant having at least two polar groups selected from sulfone group, phosphoric acid group, amino group and hydroxyl group and having a molecular weight of 10,000 or less together with magnetic powder. recoding media
水酸基から選ばれる少なくとも２以上の極性基を有する
分子量が１００００以下の多官能基分散剤を、磁性粉末
に対して 0.5〜2.0 重量％含有させた請求項１記載の磁
気記録媒体2. A polyfunctional group dispersant having at least two polar groups selected from sulfone groups, phosphoric acid groups, amino groups and hydroxyl groups and having a molecular weight of 10,000 or less is contained in an amount of 0.5 to 2.0% by weight based on the magnetic powder. The magnetic recording medium according to claim 1,
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34963991A JPH05159279A (en) | 1991-12-06 | 1991-12-06 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP34963991A JPH05159279A (en) | 1991-12-06 | 1991-12-06 | Magnetic recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH05159279A true JPH05159279A (en) | 1993-06-25 |
Family
ID=18405097
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP34963991A Withdrawn JPH05159279A (en) | 1991-12-06 | 1991-12-06 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH05159279A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20190075506A (en) * | 2017-12-21 | 2019-07-01 | 주식회사 삼양사 | Thermoplastic elastomer resin composition comprising mica and molded article comprising the same |
-
1991
- 1991-12-06 JP JP34963991A patent/JPH05159279A/en not_active Withdrawn
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR20190075506A (en) * | 2017-12-21 | 2019-07-01 | 주식회사 삼양사 | Thermoplastic elastomer resin composition comprising mica and molded article comprising the same |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| JPH05159279A (en) | Magnetic recording medium | |
| US20040191570A1 (en) | Magnetic recording media having increased high density broadband signal-to-noise ratio | |
| JPH09212847A (en) | Magnetic recording medium | |
| JP2912979B2 (en) | Flexible magnetic disk | |
| JP2632943B2 (en) | Magnetic recording media | |
| JP3037454B2 (en) | Magnetic recording media | |
| JP3521002B2 (en) | Magnetic recording medium and method for manufacturing the same | |
| JPH0729151A (en) | Magnetic recording medium | |
| JP2993092B2 (en) | Magnetic recording media | |
| JP2702163B2 (en) | Magnetic recording media | |
| JPS60234231A (en) | Magnetic recording medium | |
| JPH0729153A (en) | Magnetic recording medium | |
| JPH03183012A (en) | Magnetic recording medium | |
| JPH06162482A (en) | Magnetic recording medium | |
| JPH04121816A (en) | magnetic recording medium | |
| JPH06349051A (en) | Magnetic recording medium | |
| JPH06349052A (en) | Magnetic recording medium | |
| JPH06162481A (en) | Magnetic recording medium | |
| JPH02304715A (en) | Magnetic recording medium | |
| JPH10270228A (en) | Magnetic powder and magnetic recording medium using the same | |
| JPH0729155A (en) | Magnetic recording medium | |
| JPH0845063A (en) | Magnetic recording medium | |
| JPH10308013A (en) | Magnetic recording medium and its production | |
| JPH0773452A (en) | Magnetic recording medium | |
| JPS6070515A (en) | Magnetic recording medium |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| A300 | Withdrawal of application because of no request for examination |
Free format text: JAPANESE INTERMEDIATE CODE: A300 Effective date: 19990311 |