JPH01116923A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPH01116923A JPH01116923A JP27370387A JP27370387A JPH01116923A JP H01116923 A JPH01116923 A JP H01116923A JP 27370387 A JP27370387 A JP 27370387A JP 27370387 A JP27370387 A JP 27370387A JP H01116923 A JPH01116923 A JP H01116923A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic powder
- magnetic
- powder
- surface treatment
- kneading
- 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
- 239000006247 magnetic powder Substances 0.000 claims abstract description 54
- 125000000468 ketone group Chemical group 0.000 claims abstract description 6
- 239000003960 organic solvent Substances 0.000 claims description 17
- 238000009835 boiling Methods 0.000 claims description 9
- 238000004381 surface treatment Methods 0.000 abstract description 19
- 238000004898 kneading Methods 0.000 abstract description 18
- 235000014113 dietary fatty acids Nutrition 0.000 abstract description 8
- 229930195729 fatty acid Natural products 0.000 abstract description 8
- 239000000194 fatty acid Substances 0.000 abstract description 8
- 150000004665 fatty acids Chemical class 0.000 abstract description 8
- 125000000524 functional group Chemical group 0.000 abstract description 6
- 239000000843 powder Substances 0.000 abstract description 5
- 239000006185 dispersion Substances 0.000 abstract description 4
- 239000011230 binding agent Substances 0.000 abstract description 3
- 238000006243 chemical reaction Methods 0.000 abstract description 2
- 238000001179 sorption measurement Methods 0.000 abstract description 2
- 239000002904 solvent Substances 0.000 abstract 3
- 238000007596 consolidation process Methods 0.000 abstract 2
- 239000002245 particle Substances 0.000 abstract 2
- 230000001050 lubricating effect Effects 0.000 abstract 1
- 238000000034 method Methods 0.000 description 15
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 14
- 239000003973 paint Substances 0.000 description 14
- 230000000052 comparative effect Effects 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
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- 238000003756 stirring Methods 0.000 description 5
- NGAZZOYFWWSOGK-UHFFFAOYSA-N heptan-3-one Chemical compound CCCCC(=O)CC NGAZZOYFWWSOGK-UHFFFAOYSA-N 0.000 description 4
- 239000010936 titanium Substances 0.000 description 4
- 238000001035 drying Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 238000011282 treatment Methods 0.000 description 3
- OJVAMHKKJGICOG-UHFFFAOYSA-N 2,5-hexanedione Chemical compound CC(=O)CCC(C)=O OJVAMHKKJGICOG-UHFFFAOYSA-N 0.000 description 2
- HCFAJYNVAYBARA-UHFFFAOYSA-N 4-heptanone Chemical compound CCCC(=O)CCC HCFAJYNVAYBARA-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 239000007822 coupling agent Substances 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000000314 lubricant Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 230000000704 physical effect Effects 0.000 description 2
- 239000013557 residual solvent Substances 0.000 description 2
- 239000000243 solution Substances 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000006229 carbon black Substances 0.000 description 1
- 125000003178 carboxy group Chemical group [H]OC(*)=O 0.000 description 1
- 239000013522 chelant Chemical class 0.000 description 1
- 238000004140 cleaning Methods 0.000 description 1
- 230000001112 coagulating effect Effects 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 238000010790 dilution Methods 0.000 description 1
- 239000012895 dilution Substances 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- 238000009434 installation Methods 0.000 description 1
- 230000002452 interceptive effect Effects 0.000 description 1
- -1 menthyl oxide Chemical compound 0.000 description 1
- 239000002184 metal Substances 0.000 description 1
- 229910052751 metal Inorganic materials 0.000 description 1
- 150000002736 metal compounds Chemical class 0.000 description 1
- 125000002496 methyl group Chemical group [H]C([H])([H])* 0.000 description 1
- WSGCRAOTEDLMFQ-UHFFFAOYSA-N nonan-5-one Chemical compound CCCCC(=O)CCCC WSGCRAOTEDLMFQ-UHFFFAOYSA-N 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 238000003672 processing method Methods 0.000 description 1
- 239000011347 resin Substances 0.000 description 1
- 229920005989 resin Polymers 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 229920002803 thermoplastic polyurethane Polymers 0.000 description 1
- 229910006297 γ-Fe2O3 Inorganic materials 0.000 description 1
Landscapes
- Paints Or Removers (AREA)
- Magnetic Record Carriers (AREA)
Abstract
Description
【発明の詳細な説明】
産業上の利用分野
本発明は磁気記録媒体に関し、特に磁性粉末を有機溶剤
で表面処理することにより硬練り混合混練で分散性よく
得られる磁性塗料によってつくられる磁気記録媒体に関
するものである。DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to magnetic recording media, and in particular to magnetic recording media made from magnetic paint that can be obtained with good dispersibility by hard kneading and kneading by surface treating magnetic powder with an organic solvent. It is related to.
従来の技術
磁気テープやフロ・ソピーディスクなどの磁気記録媒体
の製造に用いられる磁性塗料は、その中で磁性粉が高分
散であることが要求される。特に最近、高密度磁気記録
化に対する要求から、用いられる磁性粉がよシ微粉化の
方向にあり、高分散が困難になってきたことに対して、
磁性粉に有機的、或いは無機的な表面処理を施したり、
分散剤を用いる等の工夫がなされている。例えば特開昭
６１−１４７０５のように磁性金属粉表面を界面活性剤
を含有する水溶液で表面処理する方法、或いは特開昭６
０−１０７７３−１．６Ｏ−ＩＬ２７５２６のようにチ
タンカップリング剤で表面処理する方法、また特開昭６
０−１７５２１３ 、６０−１７１５２１４．６０−１
７５２１５のように金属の化合物、及びキレート化合物
で表面処理する方法等、様々な有機的、無機的な表面処
理方法が示されている。BACKGROUND OF THE INVENTION Magnetic paints used in the manufacture of magnetic recording media such as magnetic tapes and fluoroscopic disks are required to have highly dispersed magnetic powder therein. In particular, due to the recent demand for high-density magnetic recording, the magnetic powder used has become increasingly finer, making it difficult to achieve high dispersion.
Applying organic or inorganic surface treatment to magnetic powder,
Efforts have been made such as using a dispersant. For example, a method of treating the surface of magnetic metal powder with an aqueous solution containing a surfactant as disclosed in JP-A-61-14705, or a method as disclosed in JP-A-61-14705.
A method of surface treatment with a titanium coupling agent such as 0-10773-1.6O-IL27526, and a method of surface treatment with a titanium coupling agent as in JP-A No. 6
0-175213, 60-1715214.60-1
Various organic and inorganic surface treatment methods have been shown, such as methods of surface treatment with metal compounds and chelate compounds as in No. 75215.
−また塗料化工法の面からも、ニーダ−、インターナル
ミキサー、バンバリーミキサ−１或いはプラネタリ−ミ
キサー、等の混練装置を用いて磁性粉の硬練りを行なう
など、磁性粉を高分散させる為の工夫がなされている。-Also, from the perspective of paint processing methods, magnetic powder is hard-kneaded using kneading equipment such as a kneader, internal mixer, Banbury mixer 1, or planetary mixer, etc., to make the magnetic powder highly dispersed. Efforts have been made.
発明が解決しようとする問題点
しかし従来技術による磁性粉の表面処理方法において有
機的な処理の場合は、磁性層中に存在する高級脂肪酸の
絶対量が多くなることから、磁性粉の分散性は向上する
が塗膜物性が弱くなりスチル特性等が著しく劣化する。Problems to be Solved by the Invention However, in the case of organic treatment in the surface treatment method of magnetic powder according to the prior art, the absolute amount of higher fatty acids present in the magnetic layer increases, so the dispersibility of the magnetic powder is However, the physical properties of the coating film become weaker and the still characteristics etc. deteriorate significantly.
また無機的な処理の場合は、逆に塗料化の後工程で添加
する高級脂肪酸が表面処理された磁性粉表面に吸着して
磁性層表面に浮き出てこないため、磁気テープとした場
合に摩擦係数が非常に大きくなり、走行性の面で常置が
生じる。In addition, in the case of inorganic treatment, on the other hand, higher fatty acids added in the post-process of forming paint are adsorbed to the surface of the surface-treated magnetic powder and do not stand out on the surface of the magnetic layer. becomes very large, and permanent installation occurs in terms of running performance.
さらにこれらの表面処理の多くは磁性塗料に最も不適当
な材料である水を用いること、そしてそのために表面処
理後磁性粉を十分に洗浄、乾燥を行なう必要があり工程
が非常に複雑になり、実験スケールの少量の処理はとも
かく、工場における大量処理には不適当である。Furthermore, many of these surface treatments use water, which is the most unsuitable material for magnetic paints, and the process becomes extremely complicated because the magnetic powder must be thoroughly washed and dried after surface treatment. Apart from small-scale processing on an experimental scale, it is unsuitable for large-scale processing in factories.
問題点を解決するための手段
本発明者はかかる現状に鑑み種々検討を行なった結果、
磁性粉末に対し６〜１０重量％の、沸点が１２０〜１７
０℃で分子構造中にケトン基Ｃ＝Ｏを含有する有機溶剤
によって表面処理を行なえば、塗膜物性を劣化させるこ
となく磁性粉が高分散され、走行性及び電磁変換特性に
優れた磁気記録媒体が得られることを見い出した。Means for Solving the Problems The present inventor has conducted various studies in view of the current situation, and has found the following:
6-10% by weight of magnetic powder, boiling point 120-17
If the surface is treated with an organic solvent containing a ketone group C=O in its molecular structure at 0°C, the magnetic powder will be highly dispersed without deteriorating the physical properties of the coating, resulting in magnetic recording with excellent running properties and electromagnetic conversion properties. It was found that a medium can be obtained.
作 用
上記の構成によシ、磁性粉末を硬練りにより塗料化する
工程で上記有機溶剤で表面処理することが可能となり、
またこの有機溶剤は磁性塗料中に一般的に使用されてい
ることなどから、表面処理に伴う洗浄、乾燥等の工程を
経る必要もなく、最終的に磁気記録媒体とした場合にも
特性的な劣化を生じることはない。Effect: Due to the above structure, it is possible to perform surface treatment with the above organic solvent during the process of hard kneading the magnetic powder to form a paint.
In addition, since this organic solvent is commonly used in magnetic paints, there is no need to go through processes such as cleaning and drying associated with surface treatment, and when it is finally used as a magnetic recording medium, it does not have any characteristics. No deterioration occurs.
一般にこの種の硬練りは、混線装置容器内に適当量の磁
性粉を入れ、これに適量の有機溶剤及びバインダー溶液
を入れて、容器内に装備されている攪拌ブレードによっ
て攪拌して材料に剪断を与えて行なわれる。これを効果
的に行なうために有機溶剤、バインダー溶液を少量ずつ
分割投入し、硬練り中出来るだけ均一な状態を保ちなが
ら硬練りを行なう方法が取られてきた。本発明はこの硬
練りを行なう過程において、上記有機溶剤によって磁性
粉の表面処理を行なうものである。すなわち所定量の磁
性粉を混練装置容器内に投入後、攪拌ブレードで攪拌を
行ないながら、バインダー溶液を添加する前に沸点１２
０〜１７０℃で分子構造中にケトン基Ｃ＝Ｏを含有する
有機溶剤を、磁性粉に対し６〜１０重量％添加を６行な
い、一定時間攪拌することで磁性粉の表面処理を行なう
ものである。Generally, in this type of hard kneading, an appropriate amount of magnetic powder is placed in a mixer container, and an appropriate amount of organic solvent and binder solution is added to this, and the mixture is stirred by a stirring blade installed in the container to shear the material. It is done by giving In order to effectively accomplish this, a method has been adopted in which the organic solvent and binder solution are added in portions little by little, and the hard kneading is carried out while maintaining as uniform a state as possible during the hard kneading. In the present invention, the surface of the magnetic powder is treated with the above organic solvent during the hard kneading process. That is, after putting a predetermined amount of magnetic powder into a kneading device container, while stirring with a stirring blade, the boiling point is 12
The surface treatment of magnetic powder is carried out by adding 6 to 10% by weight of an organic solvent containing a ketone group C=O in the molecular structure to magnetic powder at 0 to 170°C six times and stirring for a certain period of time. be.
磁性粉は親水性粉体であり、表面には多数の水分子或い
は、水酸基、カルボキシル基等の親水性官能基が存在し
ている。これらの官能基は化、学的に非常に活性で、他
の親水性官能基と容易に結合するため、硬練り中に磁性
粉同士を固結させ分散性を低下させる原因となっていた
。本発明者は、磁性粉の硬練り前に分子構造中に親水性
官能基を含有する有機溶剤を添加し攪拌混合を行なえば
、磁性粉表面の親水性官能基と容易に吸着結合し、一種
の表面処理的な役割を果たし、磁性粉同士の固結を防ぎ
分散性を向上させることに着目し、この発明をなすに至
った。Magnetic powder is a hydrophilic powder, and a large number of water molecules or hydrophilic functional groups such as hydroxyl groups and carboxyl groups are present on the surface. These functional groups are chemically and chemically very active and easily combine with other hydrophilic functional groups, which causes the magnetic powders to clump together during hard kneading, reducing dispersibility. The present inventor has discovered that if an organic solvent containing a hydrophilic functional group in the molecular structure is added and mixed with stirring before hard kneading of the magnetic powder, it will easily adsorb and bond with the hydrophilic functional group on the surface of the magnetic powder. This invention was developed by focusing on the role of surface treatment, preventing caking of magnetic powders and improving dispersibility.
さらに磁性粉表面に吸着結合した上記有機溶剤は、磁性
粉同士の固結を防ぐとともに、硬練り後の分散工程にお
いて添加する高級脂肪酸等の潤滑剤の磁性粉表面への吸
着結合も防ぐために、摩擦係数の低い走行性にも優れた
磁気記録媒体が得られる。Furthermore, the above-mentioned organic solvent adsorbed and bonded to the magnetic powder surface prevents the magnetic powders from caking together, and also prevents lubricants such as higher fatty acids added in the dispersion process after hard kneading from adsorbing and bonding to the magnetic powder surface. A magnetic recording medium with a low coefficient of friction and excellent running properties can be obtained.
本発明に用いられる沸点が１２０〜，１７０℃で分子構
造中にケトン基Ｃ＝ｏを含有する有機溶剤としては、エ
チル−ｎ−ブチルケトン、ジーｎ −プロピルケトン、
ジインブチルケトン、メンチルオキシド、シクロヘキサ
ノン、等が好適なものとして使用される。Examples of the organic solvent used in the present invention having a boiling point of 120 to 170°C and containing a ketone group C=o in the molecular structure include ethyl-n-butyl ketone, di-n-propyl ketone,
Diyne butyl ketone, menthyl oxide, cyclohexanone, etc. are preferably used.
これらの有機溶剤の沸点としては、１２０〜１７０℃が
好ましい。１２０℃よシ低いと分子量が小さく磁性粉表
面への結合力も弱いため、磁性粉表面に硬練り前に一度
吸着結合しても、硬練り後の希釈９分散工程において磁
性粉表面より脱離し、その結果磁性塗料中の高級脂肪酸
等が磁性粉表面に吸着し、磁気テープとした場合の走行
性の低下の原因となる。逆に１７０℃より高いと、分子
量も大きく磁性粉表面に強固に吸着結合し、沸点も高い
ことから磁気テープ製造の乾燥工程において十分に蒸発
せず、塗膜中に残留溶剤として多量に残存し、磁気テー
プとした場合に耐久性、特にスチル特性の劣化が起こる
。The boiling point of these organic solvents is preferably 120 to 170°C. If the temperature is lower than 120°C, the molecular weight is small and the binding force to the magnetic powder surface is weak, so even if it is once adsorbed and bonded to the magnetic powder surface before hard kneading, it will be desorbed from the magnetic powder surface in the dilution 9 dispersion process after hard kneading. As a result, higher fatty acids and the like in the magnetic paint are adsorbed to the surface of the magnetic powder, causing a decrease in running performance when used as a magnetic tape. On the other hand, if the temperature is higher than 170°C, the molecular weight is large and it is strongly adsorbed and bonded to the surface of the magnetic powder, and its boiling point is also high, so it does not evaporate sufficiently in the drying process of magnetic tape manufacturing, and a large amount remains as a residual solvent in the coating film. When used as a magnetic tape, durability, especially still characteristics, deteriorates.
またこれらの有機溶剤は磁性粉に対して５〜１０重量％
の範囲内で使用することが好ましく、これより少ないと
、表面処理が不十分となるため、磁性粉同士の固結、或
いは磁性粉表面への高級脂肪酸の吸着等を招き、分散性
及び磁気テープとした場合の走行性の低下の原因となる
。逆に多いと塗膜中に多量に残存するため、磁気テープ
としての耐久性、特にスチル特性の劣化が起こる。In addition, these organic solvents are used in an amount of 5 to 10% by weight based on the magnetic powder.
If it is less than this, the surface treatment will be insufficient, leading to caking of the magnetic powders or adsorption of higher fatty acids to the surface of the magnetic powders, resulting in poor dispersibility and magnetic tape. This may cause a decrease in running performance. On the other hand, if the amount is too large, a large amount remains in the coating film, resulting in deterioration of the durability of the magnetic tape, especially the still characteristics.
実施例 次に本発明の実施例について説明する。Example Next, examples of the present invention will be described.
（実施例１）
磁性粉（Ｃｏ被着 γ−Ｆｅ２Ｏ３）・・・・・・１０
０部カーボンブラック
（東海カーボン■ジーストＳ）・・・・・・ ３部シ
クロヘキサノン ・・・・・・ ７．６部
これらを１ｏ１加圧ニーダにて２時間攪拌混合を行ない
、表面処理品Ｉとした。(Example 1) Magnetic powder (Co coated γ-Fe2O3)...10
0 parts carbon black (Tokai Carbon ■Geast S) 3 parts cyclohexanone 7.6 parts These were stirred and mixed in a 1:1 pressure kneader for 2 hours to form surface-treated product I. did.
次にこの表面処理品■に以下に示す成分組成を徐々に添
加し、上記１ｏｌ加圧ニーダによって２時間硬練りを行
ない混練物を得た。Next, the following component composition was gradually added to the surface-treated product (1), and hard kneading was performed for 2 hours using the 1 ol pressure kneader described above to obtain a kneaded product.
表面処理品Ｉ ・・・・・・ １００
部塩化ビニル樹脂（８信化学（製））・・・・−、−１
０部メチルエチルケトン ・・・・・・ ２
６部トルエン ・・・・・・ ２
６部得られた混練物に、さらに以下に示すような成分組
成を添加したのち、ボールミルで４０時間希釈分散を行
ない磁性塗料とした。Surface treatment product I... 100
Polyvinyl chloride resin (manufactured by 8 Shin Chemical Co., Ltd.)...-, -1
0 parts methyl ethyl ketone 2
6 parts Toluene 2
6 parts of the obtained kneaded product were further added with the following component composition, and then diluted and dispersed in a ball mill for 40 hours to obtain a magnetic paint.
混線物 ・・・・・・１００
部ウレタン樹脂（タケダ薬品化学（製））・・・・・・
ｅ部粒状ｄ−Ａ［２０３粉末 ・・・
・・・ ３部潤滑剤 ・・・
・・・ １．５部メチルエチルケトン ・・
・・・・１１０部トルエン ・
・・・・・ ６０部シクロヘキサノン
・・・・・・ ４６部この磁性塗料を厚さ１６μのポリ
エステルベースフィルム上に乾燥厚が５μとなるように
塗布した後、配向磁界を印加して配向させ、次いで熱風
によシ乾燥させた後、表面平滑処理を施し、６０℃のオ
ープン中に２４時間保持した後イインチ幅に切断しビデ
オテープとした。Interfering object...100
Urethane resin (manufactured by Takeda Yakuhin Kagaku)...
e part granular d-A [203 powder...
・・・ Three-part lubricant ・・・
... 1.5 parts methyl ethyl ketone...
...110 parts toluene ・
...60 parts cyclohexanone
...... 46 parts This magnetic paint was applied onto a polyester base film with a thickness of 16 μm so that the dry thickness was 5 μm, and then an orienting magnetic field was applied to orient it, and then it was dried with hot air. Thereafter, the surface was smoothed, kept in an open air at 60°C for 24 hours, and then cut into inch width pieces to make video tapes.
（実施例２）
実施例１の表面処理品■のシクロヘキサノンに代えてエ
チル−ｎ−ブチルケトンを、７．６部使用した以外は実
施例１と同様にして表面処理品Ｉを得、これを用いて磁
性塗料を作成し、ビデオテープとした。(Example 2) A surface-treated product I was obtained in the same manner as in Example 1, except that 7.6 parts of ethyl-n-butyl ketone was used in place of cyclohexanone in the surface-treated product (1) of Example 1. They created magnetic paint and used it as a videotape.
（比較例１）
実施例１の表面処理品■のシクロヘキサノンの使用量を
２部とする以外は、実施例１と同様にして表面処理品Ｉ
を得、これを用いて磁性塗料を作成し、ビデオテープと
した。(Comparative Example 1) Surface-treated product I was prepared in the same manner as in Example 1, except that the amount of cyclohexanone used in surface-treated product I of Example 1 was changed to 2 parts.
This was used to create magnetic paint, which was then used as a videotape.
（比較例２）
実施例１０表面処理品Ｉのシクロヘキサノンに代えてア
セトニルアセトン（沸点１９０℃）を、７．５部使用し
た以外は実施例１と同様にして表面処理品Ｉを得、これ
を用いて磁性塗料を作用し、ビデオテープとした。(Comparative Example 2) A surface-treated product I was obtained in the same manner as in Example 1, except that 7.5 parts of acetonylacetone (boiling point 190°C) was used in place of cyclohexanone in the surface-treated product I of Example 10. A videotape was created by applying magnetic paint to the film.
（比較例３）
実施例１において、磁性粉のシクロヘキサノンによる表
面処理を行なわずに混練物を得、これを用いて磁性塗料
を作成し、ビデオテープとした。(Comparative Example 3) In Example 1, a kneaded product was obtained without subjecting the surface of the magnetic powder to the cyclohexanone treatment, and a magnetic paint was prepared using the kneaded product, which was then used as a videotape.
第１表に実施例及び比較例によって得られたビデオテー
プのビデオＳＮ比、スチル特性、及び摩擦係数（μＫ）
の測定結果を示す。Table 1 shows the video SN ratio, still characteristics, and friction coefficient (μK) of the videotapes obtained in Examples and Comparative Examples.
The measurement results are shown below.
ここでビデオＳＮ比は１００％自画像の信号対雑音レベ
ルの比であり、市販のレギュラーテープに対する値を示
している。スチル特性は、市販の標準ＶＴＲによって０
℃、ａｏＲＨ％の環境下における測定結果である。また
摩擦係数（μＫ）は、ビデオテープを４φのステンレス
ピンに１８０度の角度で巻き付けた状態で４ ａｘ ７
秒で走行させたトキの、入側テンションＴｉ と出側テ
ンションＴ。Here, the video SN ratio is the ratio of the signal to noise level of a 100% self-portrait, and indicates the value for a commercially available regular tape. The still characteristics are 0.
It is a measurement result in the environment of °C and aoRH%. The coefficient of friction (μK) is 4 ax 7 when the video tape is wrapped around a 4φ stainless steel pin at an angle of 180 degrees.
Entrance tension Ti and exit tension T of the Toki that ran in seconds.
の値を読み出し次式より求めた。The value was read out and calculated using the following formula.
μに＝ｌｎ（Ｔｏ／Ｔｉ）／π
第１表より明らかなように、分子構造中にケトン基Ｃ＝
ｏを含有する沸点１２０〜１７０℃の有機溶剤によって
磁性粉を表面処理した場合（実施例１．２）には、ビデ
オＳＮ比が高く、メチル特性及び摩擦係数が低く走行性
にも優れたビデオテープが得られた。μ=ln(To/Ti)/π As is clear from Table 1, the ketone group C=
When the magnetic powder was surface-treated with an organic solvent with a boiling point of 120 to 170°C containing o (Example 1.2), a video with a high video S/N ratio, low methyl properties and friction coefficient, and excellent running properties was obtained. Got the tape.
表面処理に用いる有機溶剤量が少ない場合（比較例１）
或いは全く表面処理を行々わない場合（比較例３）は、
磁性粉同士の固結、高級脂肪酸の吸着が起こり、ビデオ
ＳＮ比が低く、摩擦係数も高くなっている二
また沸点の高い有機溶剤を用いた場合（比較例２）は、
乾燥工程において十分に蒸発せず、塗膜中に残留溶剤と
して残存しているため、スチル特性が劣化している。When the amount of organic solvent used for surface treatment is small (Comparative Example 1)
Or when no surface treatment is performed at all (Comparative Example 3),
When using an organic solvent with a high boiling point (Comparative Example 2), the magnetic powders solidify and higher fatty acids are adsorbed, the video S/N ratio is low, and the coefficient of friction is high.
The still characteristics deteriorate because it is not sufficiently evaporated during the drying process and remains as a residual solvent in the coating film.
発明の効果
以上述べたように、本発明によって磁性粉の表面処理を
、簡便に効果的に行なうことが可能となり、その結果磁
性粉同士の固結、或いは磁性粉への高級脂肪酸の吸着を
防ぐことができ、ビデオＳＮ比、スチル特性、摩擦係数
に優れた磁気記録媒体を得ることができる。Effects of the Invention As described above, the present invention makes it possible to easily and effectively perform the surface treatment of magnetic powder, and as a result, it is possible to prevent the magnetic powder from coagulating with each other or from adsorbing higher fatty acids to the magnetic powder. Therefore, it is possible to obtain a magnetic recording medium with excellent video S/N ratio, still characteristics, and coefficient of friction.
Claims (1)
０℃で、分子構造中にケトン基Ｃ＝Ｏを含有する有機溶
剤によって表面処理した磁性粉末を用いることを特徴と
する磁気記録媒体。5 to 10% by weight of magnetic powder with a boiling point of 120 to 17
A magnetic recording medium characterized in that it uses magnetic powder whose surface is treated at 0° C. with an organic solvent containing a ketone group C═O in its molecular structure.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27370387A JPH01116923A (en) | 1987-10-29 | 1987-10-29 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP27370387A JPH01116923A (en) | 1987-10-29 | 1987-10-29 | Magnetic recording medium |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH01116923A true JPH01116923A (en) | 1989-05-09 |
Family
ID=17531380
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP27370387A Pending JPH01116923A (en) | 1987-10-29 | 1987-10-29 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH01116923A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8064657B2 (en) | 2008-03-05 | 2011-11-22 | Nec Corporation | Cleaning device for fingerprint authentication apparatus, cleaning method, and fingerprint authentication system using the same |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6025028A (en) * | 1983-07-21 | 1985-02-07 | Fuji Photo Film Co Ltd | Manufacture of magnetic recording medium |
-
1987
- 1987-10-29 JP JP27370387A patent/JPH01116923A/en active Pending
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6025028A (en) * | 1983-07-21 | 1985-02-07 | Fuji Photo Film Co Ltd | Manufacture of magnetic recording medium |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US8064657B2 (en) | 2008-03-05 | 2011-11-22 | Nec Corporation | Cleaning device for fingerprint authentication apparatus, cleaning method, and fingerprint authentication system using the same |
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