JP2940117B2 - Ferromagnetic metal particles for magnetic recording media - Google Patents
Ferromagnetic metal particles for magnetic recording mediaInfo
- Publication number
- JP2940117B2 JP2940117B2 JP2247333A JP24733390A JP2940117B2 JP 2940117 B2 JP2940117 B2 JP 2940117B2 JP 2247333 A JP2247333 A JP 2247333A JP 24733390 A JP24733390 A JP 24733390A JP 2940117 B2 JP2940117 B2 JP 2940117B2
- Authority
- JP
- Japan
- Prior art keywords
- ferromagnetic metal
- metal particles
- magnetic recording
- naphthalenedicarboxylic acid
- anhydride
- 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 - Fee Related
Links
- 230000005294 ferromagnetic effect Effects 0.000 title claims description 65
- 239000002923 metal particle Substances 0.000 title claims description 53
- 230000005291 magnetic effect Effects 0.000 title claims description 34
- KHARCSTZAGNHOT-UHFFFAOYSA-N naphthalene-2,3-dicarboxylic acid Chemical compound C1=CC=C2C=C(C(O)=O)C(C(=O)O)=CC2=C1 KHARCSTZAGNHOT-UHFFFAOYSA-N 0.000 claims description 18
- 150000008064 anhydrides Chemical class 0.000 claims description 17
- HRRDCWDFRIJIQZ-UHFFFAOYSA-N naphthalene-1,8-dicarboxylic acid Chemical compound C1=CC(C(O)=O)=C2C(C(=O)O)=CC=CC2=C1 HRRDCWDFRIJIQZ-UHFFFAOYSA-N 0.000 claims description 7
- 239000007769 metal material Substances 0.000 claims description 6
- 239000000956 alloy Substances 0.000 claims description 5
- 239000010419 fine particle Substances 0.000 claims description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 16
- 238000007254 oxidation reaction Methods 0.000 description 16
- 230000003647 oxidation Effects 0.000 description 15
- 239000003795 chemical substances by application Substances 0.000 description 11
- 230000005415 magnetization Effects 0.000 description 9
- 238000000034 method Methods 0.000 description 9
- 239000000843 powder Substances 0.000 description 9
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 8
- 150000001875 compounds Chemical class 0.000 description 8
- 229910052742 iron Inorganic materials 0.000 description 8
- 239000006247 magnetic powder Substances 0.000 description 7
- 230000000052 comparative effect Effects 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- XNGIFLGASWRNHJ-UHFFFAOYSA-N phthalic acid group Chemical group C(C=1C(C(=O)O)=CC=CC1)(=O)O XNGIFLGASWRNHJ-UHFFFAOYSA-N 0.000 description 6
- 238000003860 storage Methods 0.000 description 6
- 238000004381 surface treatment Methods 0.000 description 6
- 239000011248 coating agent Substances 0.000 description 5
- 238000000576 coating method Methods 0.000 description 5
- KYTZHLUVELPASH-UHFFFAOYSA-N naphthalene-1,2-dicarboxylic acid Chemical compound C1=CC=CC2=C(C(O)=O)C(C(=O)O)=CC=C21 KYTZHLUVELPASH-UHFFFAOYSA-N 0.000 description 5
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 4
- 238000006243 chemical reaction Methods 0.000 description 4
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 4
- 230000014759 maintenance of location Effects 0.000 description 4
- 239000003960 organic solvent Substances 0.000 description 4
- 239000003973 paint Substances 0.000 description 4
- 239000002245 particle Substances 0.000 description 4
- 239000011347 resin Substances 0.000 description 4
- 229920005989 resin Polymers 0.000 description 4
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- GRSMWKLPSNHDHA-UHFFFAOYSA-N Naphthalic anhydride Chemical compound C1=CC(C(=O)OC2=O)=C3C2=CC=CC3=C1 GRSMWKLPSNHDHA-UHFFFAOYSA-N 0.000 description 3
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 3
- 125000003118 aryl group Chemical group 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- CSCPPACGZOOCGX-UHFFFAOYSA-N Acetone Chemical compound CC(C)=O CSCPPACGZOOCGX-UHFFFAOYSA-N 0.000 description 2
- 229910020630 Co Ni Inorganic materials 0.000 description 2
- 229910002440 Co–Ni Inorganic materials 0.000 description 2
- 229910017061 Fe Co Inorganic materials 0.000 description 2
- CUPCBVUMRUSXIU-UHFFFAOYSA-N [Fe].OOO Chemical compound [Fe].OOO CUPCBVUMRUSXIU-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 2
- 239000011230 binding agent Substances 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 229910052802 copper Inorganic materials 0.000 description 2
- 238000006297 dehydration reaction Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 2
- 229910021519 iron(III) oxide-hydroxide Inorganic materials 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 150000002739 metals Chemical class 0.000 description 2
- 239000001301 oxygen Substances 0.000 description 2
- 229910052760 oxygen Inorganic materials 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 230000002123 temporal effect Effects 0.000 description 2
- 229910052719 titanium Inorganic materials 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- ROFVEXUMMXZLPA-UHFFFAOYSA-N Bipyridyl Chemical group N1=CC=CC=C1C1=CC=CC=N1 ROFVEXUMMXZLPA-UHFFFAOYSA-N 0.000 description 1
- 229910020516 Co—V Inorganic materials 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- 229910018104 Ni-P Inorganic materials 0.000 description 1
- 229910018487 Ni—Cr Inorganic materials 0.000 description 1
- 229910018536 Ni—P Inorganic materials 0.000 description 1
- 229910018605 Ni—Zn Inorganic materials 0.000 description 1
- -1 acetone Chemical compound 0.000 description 1
- 239000002253 acid Substances 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 239000005456 alcohol based solvent Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- 239000003849 aromatic solvent Substances 0.000 description 1
- IZJDCINIYIMFGX-UHFFFAOYSA-N benzo[f][2]benzofuran-1,3-dione Chemical group C1=CC=C2C=C3C(=O)OC(=O)C3=CC2=C1 IZJDCINIYIMFGX-UHFFFAOYSA-N 0.000 description 1
- DMMLYDCVMZEUMT-UHFFFAOYSA-N benzo[h]cinnoline Chemical compound C1=NN=C2C3=CC=CC=C3C=CC2=C1 DMMLYDCVMZEUMT-UHFFFAOYSA-N 0.000 description 1
- 238000006664 bond formation reaction Methods 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical group 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 230000018044 dehydration Effects 0.000 description 1
- 238000007654 immersion Methods 0.000 description 1
- 239000005453 ketone based solvent Substances 0.000 description 1
- 239000007791 liquid phase Substances 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 238000012856 packing Methods 0.000 description 1
- 239000012071 phase Substances 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 230000003449 preventive effect Effects 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000001179 sorption measurement Methods 0.000 description 1
- 239000004094 surface-active agent Substances 0.000 description 1
- 238000001291 vacuum drying Methods 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
Landscapes
- Paints Or Removers (AREA)
- Powder Metallurgy (AREA)
- Magnetic Record Carriers (AREA)
- Hard Magnetic Materials (AREA)
Description
【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、磁気記録媒体の磁性粉末として使用される
磁気記録媒体用強磁性金属粒子に関する。Description: TECHNICAL FIELD The present invention relates to a ferromagnetic metal particle for a magnetic recording medium used as a magnetic powder of a magnetic recording medium.
本発明は、磁気記録媒体の磁性粉末として使用される
強磁性金属粒子をナフタレンジカルボン酸又はその無水
物により表面処理することにより、耐酸化性，耐錆性の
向上を図ろうとするものである。The present invention seeks to improve oxidation resistance and rust resistance by subjecting ferromagnetic metal particles used as magnetic powder of a magnetic recording medium to surface treatment with naphthalenedicarboxylic acid or an anhydride thereof.
近年、強磁性金属粒子として、非常に微細な粒子形状
を有するものが供給されるようになってきており、これ
を磁気記録媒体の磁性粉末に用いることで、高記録密度
化や高周波数帯域における優れた電磁変換特性が達成さ
れている。In recent years, ferromagnetic metal particles having a very fine particle shape have been supplied. By using this as a magnetic powder of a magnetic recording medium, high recording density and high frequency band can be obtained. Excellent electromagnetic conversion characteristics have been achieved.
ところで、この強磁性金属粒子は、従来より磁気記録
媒体等の磁性粉末の構成材料として使用された酸化鉄系
材料に代わり、鉄又は鉄を主体とする金属材料が用いら
れるようになっている。これらの鉄又は鉄から構成され
る強磁性金属粒子は、酸化鉄やオキシ水酸化鉄、あるい
はCo,Ni,Cr,Mn,Cu,Zn,Ti,V等の鉄以外の金属を含む酸化
鉄やオキシ水酸化鉄等を水素ガスで還元することによっ
て製造される。このような強磁性金属粒子は、従来の酸
化鉄系磁性粉末よりも優れた磁気特性を有している。The ferromagnetic metal particles are made of iron or iron-based metal materials instead of iron oxide-based materials conventionally used as constituent materials of magnetic powders such as magnetic recording media. These iron or ferromagnetic metal particles composed of iron include iron oxide and iron oxyhydroxide, or iron oxide containing metals other than iron such as Co, Ni, Cr, Mn, Cu, Zn, Ti, and V. It is produced by reducing iron oxyhydroxide and the like with hydrogen gas. Such ferromagnetic metal particles have better magnetic properties than conventional iron oxide-based magnetic powder.
ところが、この強磁性金属粒子は、表面活性が高く、
大気中で酸化され易く、場合によっては発火を供う虞れ
がある。このため、このような強磁性金属粒子の経時的
な磁気特性の劣化が問題となっている。例えば、強磁性
金属粒子の保存中，或いは樹脂や有機溶剤等との組み合
わせによる塗料化の工程中、さらにはポリエステルフィ
ルム等の支持体上に塗布してシート化した後、所定の雰
囲気や温度、湿度等の条件下での保管中に、主として酸
素、ある種のガス及び水分等の影響により酸化が進行す
る。その結果、磁化量の低下や場合によっては抗磁力の
低下が起こり、強磁性金属粒子は本来有する特性を損な
うことになる。However, these ferromagnetic metal particles have high surface activity,
It is easily oxidized in the atmosphere and may cause ignition in some cases. Therefore, there is a problem that the magnetic properties of such ferromagnetic metal particles deteriorate with time. For example, during storage of the ferromagnetic metal particles, or during the process of coating with a resin or an organic solvent or the like, and further, after coating on a support such as a polyester film to form a sheet, a predetermined atmosphere and temperature, During storage under conditions such as humidity, oxidation proceeds mainly due to the influence of oxygen, certain gases, moisture, and the like. As a result, the amount of magnetization and, in some cases, the coercive force decrease, and the ferromagnetic metal particles lose their inherent properties.
この問題に対して、強磁性金属粒子の表面の安定化を
図るために、一般的には液相法、又は気相法で粒子の表
面に酸化皮膜を形成して、不動態化させる方法が行われ
ている。また、強磁性金属粒子の表面をある種の金属元
素や界面活性剤，樹脂等の有機物で覆う方法等も知られ
ている。In order to stabilize the surface of ferromagnetic metal particles, a method of forming an oxide film on the surface of particles by a liquid phase method or a gas phase method and passivating the particles is generally used. Is being done. There is also known a method of covering the surface of ferromagnetic metal particles with an organic substance such as a certain metal element, a surfactant, and a resin.
しかしながら、前述の酸化皮膜を形成する方法やある
種の金属元素や有機物で覆う方法では、耐酸化性の向上
を図る上で必ずしも十分なものとは言い難い。また、処
理の方法によっては、表面処理すること自体が磁気特性
の劣化をもたらす場合や分散性の低下をきたす虞れがあ
る。However, the above-described method of forming an oxide film or covering with a certain kind of metal element or organic substance is not necessarily sufficient to improve oxidation resistance. Further, depending on the treatment method, there is a possibility that the surface treatment itself may cause deterioration of magnetic properties or may cause a decrease in dispersibility.
そこで、本発明はこのような実情に鑑みて提案された
ものであって、耐酸化性に優れ、経時的劣化の少ない磁
気記録媒体用強磁性金属粒子を提供することを目的とす
る。Accordingly, the present invention has been proposed in view of such circumstances, and has as its object to provide ferromagnetic metal particles for a magnetic recording medium having excellent oxidation resistance and little deterioration over time.
本発明者等は、上述の目的を達成せんものと鋭意研究
の結果、強磁性金属粒子の表面をナフタレンジカルボン
酸又はその無水物で化学的に修飾することにより、強磁
性金属粒子の酸化を防止することができることを見出
し、本発明を完成するに至ったものである。The present inventors have achieved diligent research to achieve the above-mentioned object, and as a result, prevent the oxidation of ferromagnetic metal particles by chemically modifying the surface of the ferromagnetic metal particles with naphthalenedicarboxylic acid or an anhydride thereof. It has been found that the present invention can be performed, and the present invention has been completed.
即ち、本発明の磁気記録媒体用強磁性金属粒子は、強
磁性金属材料または強磁性合金材料の微粒子よりなり、
2,3−ナフタレンジカルボン酸又はその無水物で表面処
理されたことを特徴とするものである。That is, the ferromagnetic metal particles for a magnetic recording medium of the present invention are composed of fine particles of a ferromagnetic metal material or a ferromagnetic alloy material,
It is characterized in that it has been surface-treated with 2,3-naphthalenedicarboxylic acid or its anhydride.
さらに本発明の磁気記録媒体用強磁性金属粒子は、強
磁性金属材料または強磁性合金材料の微粒子よりなり、
1,8−ナフタレンジカルボン酸又はその無水物で表面処
理されたことを特徴とするものである。Further, the ferromagnetic metal particles for a magnetic recording medium of the present invention are composed of fine particles of a ferromagnetic metal material or a ferromagnetic alloy material,
It is characterized in that it has been surface-treated with 1,8-naphthalenedicarboxylic acid or its anhydride.
本発明が適用される磁気記録媒体用強磁性金属粒子の
種類は何ら限定されないが、特にFe,Co,Ni等の強磁性金
属材料や、Fe−Co,Fe−Ni,Fe−Co−Ni,Co−Ni,Fe−Mn−
Zn,Fe−Ni−Zn,Fe−Co−Ni−Cr,Fe−Co−Ni−P,Fe−Co
−B,Fe−Co−Cr−B,Fe−Co−Ｖ等のFe,Co,Niを主成分と
する各種強磁性合金材料からなる強磁性金属粒子が好適
である。The type of the ferromagnetic metal particles for a magnetic recording medium to which the present invention is applied is not particularly limited, but in particular, ferromagnetic metal materials such as Fe, Co, and Ni, and Fe-Co, Fe-Ni, Fe-Co-Ni, Co-Ni, Fe-Mn-
Zn, Fe-Ni-Zn, Fe-Co-Ni-Cr, Fe-Co-Ni-P, Fe-Co
Ferromagnetic metal particles made of various ferromagnetic alloy materials containing Fe, Co, and Ni as main components, such as -B, Fe-Co-Cr-B, and Fe-Co-V, are preferable.
上記磁気記録媒体用強磁性金属粒においては、種々の
特性を改善する目的でAl,Si,Ti,Cr,Mn,Cu,2n,Mg,P等の
元素が添加されても良い。これら強磁性金属粒子の比表
面積は任意であるが、比表面積25m2/g以上、特に30m2/g
以上のものに適用した場合の有効性が大きい。Elements such as Al, Si, Ti, Cr, Mn, Cu, 2n, Mg, and P may be added to the ferromagnetic metal particles for a magnetic recording medium in order to improve various characteristics. Although the specific surface area of these ferromagnetic metal particles is optional, the specific surface area is 25 m 2 / g or more, particularly 30 m 2 / g.
The effectiveness when applied to the above is large.
本発明においては、前述のような強磁性金属粒子の表
面を2,3−ナフタレンジカルボン酸又はその無水物、1,8
−ナフタレンジカルボン酸又はその無水物、或いはこれ
ら化合物の組み合わせによって処理する。これら化合物
は、次式（１）〜（４）で表されるもので、何れもオル
ト型芳香族２価カルボン酸構造を有する。In the present invention, the surface of the ferromagnetic metal particles as described above, 2,3-naphthalenedicarboxylic acid or its anhydride, 1,8
-Treatment with naphthalenedicarboxylic acid or anhydride or a combination of these compounds. These compounds are represented by the following formulas (1) to (4), and all have an ortho-type aromatic divalent carboxylic acid structure.
上述の化合物は、最適な酸性度を有するのみならず、
例えば強磁性金属粒子の酸化層表面に存在する６配位鉄
に結合した塩基性水酸基との反応において、鉄原子間距
離、鉄原子との原子価状態を満足するような立体構造を
有し、さらには酸基が強磁性金属粒子の表面の塩基性水
酸基と十分に反応した時に、芳香族環部位が最適パッキ
ング構造をとることから、非常に良好な防錆能を発揮す
る。 The above compounds not only have optimal acidity,
For example, in the reaction with a basic hydroxyl group bonded to 6-coordinate iron present on the oxide layer surface of the ferromagnetic metal particles, having a three-dimensional structure that satisfies the distance between iron atoms and the valence state with iron atoms, Further, when the acid group sufficiently reacts with the basic hydroxyl group on the surface of the ferromagnetic metal particles, the aromatic ring site has an optimal packing structure, so that it exhibits a very good rust preventive ability.
上記処理剤により強磁性金属粒子を表面処理する方法
としては、例えば上記処理剤を有機溶媒に溶解させた処
理液中に強磁性金属粒子を浸漬する，いわゆる浸漬法が
挙げられる。この場合、上記ナフタレンジカルボン酸の
溶媒としては、特に限定されないが、水、エタノール等
のアルコール系溶媒、アセトン等のケトン系溶媒、トル
エン等の芳香族系溶媒等がいずれも使用可能である。As a method of surface-treating the ferromagnetic metal particles with the treatment agent, for example, there is a so-called immersion method in which the ferromagnetic metal particles are immersed in a treatment solution in which the treatment agent is dissolved in an organic solvent. In this case, the solvent for the naphthalenedicarboxylic acid is not particularly limited, but any of water, alcohol solvents such as ethanol, ketone solvents such as acetone, and aromatic solvents such as toluene can be used.
2,3−ナフタレンジカルボン酸又はその無水物、1,8−
ナフタレンジカルボン酸又はその無水物の強磁性金属粒
子に対する被着量としては、強磁性金属粒子100重量部
に対して0.03〜30重量部であることが好ましく、0.1〜1
0重量部であることがより好ましい。前記範囲を越えて
処理剤が過剰に存在してもその効果は変わらず、過剰分
が無駄になる。また、あまり過剰に被着しておくと、磁
気記録媒体の磁性塗膜の物性に悪影響を及ぼす虞れもあ
る。逆に、前記範囲を下回ると，即ち0.03重量部未満で
あると、効果が不足して十分な経時安定性は得られな
い。2,3-naphthalenedicarboxylic acid or its anhydride, 1,8-
The amount of the naphthalenedicarboxylic acid or anhydride to be applied to the ferromagnetic metal particles is preferably from 0.03 to 30 parts by weight, preferably from 0.1 to 1 part by weight, per 100 parts by weight of the ferromagnetic metal particles.
More preferably, it is 0 parts by weight. Even if the processing agent is present in excess beyond the above range, the effect does not change, and the excess is wasted. Further, if the coating is excessively applied, the physical properties of the magnetic coating film of the magnetic recording medium may be adversely affected. Conversely, if it is less than the above range, that is, if it is less than 0.03 parts by weight, the effect is insufficient and sufficient temporal stability cannot be obtained.
本発明の磁気記録媒体用強磁性金属粒子は、樹脂結合
剤や有機溶剤、各種添加剤とともに混練して磁性塗料と
することができ、この磁性塗料を非磁性支持体上に塗布
することにより磁気記録媒体が作製される。この場合、
樹脂結合剤や有機溶剤、各種添加剤としては、通常の磁
気記録媒体に用いられるものがいずれも使用可能であ
り、配合比等も通常の磁気記録媒体の場合に準じて設定
される。The ferromagnetic metal particles for a magnetic recording medium of the present invention can be kneaded with a resin binder, an organic solvent, and various additives to form a magnetic paint. By applying this magnetic paint to a non-magnetic support, A recording medium is manufactured. in this case,
As the resin binder, the organic solvent, and various additives, any of those used for ordinary magnetic recording media can be used, and the mixing ratio and the like are set in accordance with the case of ordinary magnetic recording media.
金属と錯形成する典型的な化合物である2,2′−ビピ
リジルや9,10−フェナンスロリンによる強磁性金属粒子
の表面処理では、強磁性金属粒子の表面にこれらの化合
物が多量に吸着するにもかかわらず、飽和磁化率の保持
率は未処理の場合とほぼ同程度であり、耐酸化性の効果
が全く発現しない。これに対して、本発明において使用
される2,3−ナフタレンジカルボン酸又はその無水物、
1,8−ナフタレンジカルボン酸又はその無水物は、処理
反応に伴って水を生成していることが確認された。この
ことは、処理剤と強磁性金属粒子表面との吸着反応が脱
水型であり、処理剤の酸素と強磁性金属粒子の表面が直
接結合する構造をとっていることを示唆するものであ
る。Surface treatment of ferromagnetic metal particles with 2,2'-bipyridyl and 9,10-phenanthroline, which are typical compounds that complex with metals, causes a large amount of these compounds to be adsorbed on the surface of ferromagnetic metal particles Nevertheless, the retention of the saturation magnetic susceptibility is almost the same as that of the untreated case, and the effect of the oxidation resistance is not exhibited at all. On the other hand, 2,3-naphthalenedicarboxylic acid or its anhydride used in the present invention,
It was confirmed that 1,8-naphthalenedicarboxylic acid or its anhydride produced water with the treatment reaction. This suggests that the adsorption reaction between the treatment agent and the surface of the ferromagnetic metal particles is of a dehydration type, and that the treatment agent has a structure in which oxygen and the surface of the ferromagnetic metal particles are directly bonded.
従って、2,3−ナフタレンジカルボン酸又はその無水
物、1,8−ナフタレンジカルボン酸又はその無水物によ
る表面処理においては、その溌水性により耐酸化性の効
果が得られるのではなく、強磁性金属粒子の表面に存在
するFe−OHと処理剤とがイオン性の強い結合を形成し、
この結合形成のポテンシャルが内部構造に影響を与え、
耐酸化性の向上に寄与すると考えられる。Therefore, in the surface treatment with 2,3-naphthalenedicarboxylic acid or its anhydride, 1,8-naphthalenedicarboxylic acid or its anhydride, the effect of oxidation resistance is not obtained due to its water repellency, and the ferromagnetic metal Fe-OH present on the surface of the particles and the treating agent form a strong ionic bond,
The potential of this bond formation affects the internal structure,
It is thought to contribute to the improvement of oxidation resistance.
即ち、強磁性金属粒子を2,3−ナフタレンジカルボン
酸又はその無水物、1,8−ナフタレンジカルボン酸又は
その無水物によって表面処理すると、これら化合物と強
磁性金属粒子の表面が脱水反応を起こし、強磁性金属粒
子の表面に上述の化合物の被膜が形成される。このよう
な被膜によって強磁性金属粒子の保存中，強磁性金属粒
子を含む磁性塗料の調製中，或いは磁気記録媒体の保管
中等に進行する強磁性金属粒子の表面の酸化反応が防止
される。That is, when the surface of the ferromagnetic metal particles is treated with 2,3-naphthalenedicarboxylic acid or its anhydride, 1,8-naphthalenedicarboxylic acid or its anhydride, the surfaces of these compounds and the ferromagnetic metal particles undergo a dehydration reaction, A film of the above compound is formed on the surface of the ferromagnetic metal particles. Such a coating prevents an oxidation reaction on the surface of the ferromagnetic metal particles that proceeds during storage of the ferromagnetic metal particles, preparation of a magnetic paint containing the ferromagnetic metal particles, or storage of the magnetic recording medium.
以下、本発明を具体的な実施例により説明するが、本
発明がこの実施例に限定されるものでないことは言うま
でもない。Hereinafter, the present invention will be described with reference to specific examples, but it goes without saying that the present invention is not limited to these examples.
実施例１ 本実施例は、処理剤として2,3−ナフタレンジカルボ
ン酸を用いた例である。Example 1 In this example, 2,3-naphthalenedicarboxylic acid was used as a treating agent.
先ず、2,3−ナフタレンジカルボン酸の1.8×10-3mol/
エタノール溶液50mlに、それぞれ微細な強磁性金属粒
子A2.5gを加えて、約８時間放置した。そして、上記強
磁性金属粒子Ａを濾過し、物理吸着した化合物を除去す
るためにメタノールで繰り返し洗浄した後、30℃の温度
の下に８時間真空乾燥を行って処理粉末を得た。First, 1.8 × 10 -3 mol / of 2,3-naphthalenedicarboxylic acid
To 50 ml of the ethanol solution, 2.5 g of fine ferromagnetic metal particles A were added, and the mixture was allowed to stand for about 8 hours. Then, the ferromagnetic metal particles A were filtered, washed repeatedly with methanol to remove the physically adsorbed compound, and vacuum-dried at a temperature of 30 ° C. for 8 hours to obtain a treated powder.
実施例２ 上記実施例１において使用した2,3−ナフタレンジカ
ルボン酸を無水2,3−ナフタレンジカルボン酸に代え
て、その他は上記実施例１と同様にして処理粉末を得
た。Example 2 A treated powder was obtained in the same manner as in Example 1 except that 2,3-naphthalenedicarboxylic acid used in Example 1 was replaced with 2,3-naphthalenedicarboxylic anhydride.
実施例３ 上記実施例１において使用した2,3−ナフタレンジカ
ルボン酸を1,8−ナフタレンジカルボン酸に代えて、そ
の他は上記実施例１と同様にして処理粉末を得た。Example 3 A treated powder was obtained in the same manner as in Example 1 except that 2,3-naphthalenedicarboxylic acid used in Example 1 was replaced with 1,8-naphthalenedicarboxylic acid.
実施例４ 上記実施例１において使用した2,3−ナフタレンジカ
ルボン酸を無水1,8−ナフタレンジカルボン酸に代え
て、その他は上記実施例１と同様にして処理粉末を得
た。Example 4 A treated powder was obtained in the same manner as in Example 1 except that 2,3-naphthalenedicarboxylic acid used in Example 1 was replaced with 1,8-naphthalenedicarboxylic anhydride.
比較例１ 上記実施例１において使用した2,3−ナフタレンジカ
ルボン酸をフタル酸に代えて、その他は上記実施例１と
同様にして処理粉末を得た。Comparative Example 1 A treated powder was obtained in the same manner as in Example 1 except that the 2,3-naphthalenedicarboxylic acid used in Example 1 was replaced with phthalic acid.
上記実施例１〜４及び比較例１において得られた各処
理粉末について、磁気特性の経時変化を調べるために、
上記真空乾燥後、未処理の強磁性金属粒子とともに抗磁
力Hc,飽和磁化量σｓを測定した。For each of the treated powders obtained in Examples 1 to 4 and Comparative Example 1, in order to examine the change over time in the magnetic properties,
After the vacuum drying, the coercive force Hc and the saturation magnetization σs were measured together with the untreated ferromagnetic metal particles.
そして、恒温恒湿槽中で、湿度60％、温度60℃の条件
下にて２週間放置した後、抗磁力Hc,飽和磁化量σｓを
測定して、飽和磁化量σｓの保持率を求めた。Then, after being left for 2 weeks in a thermo-hygrostat at a humidity of 60% and a temperature of 60 ° C., the coercive force Hc and the saturation magnetization σs were measured to determine the retention of the saturation magnetization σs. .
この結果を第１表に示す。 Table 1 shows the results.
上記2,3−ナフタレンジカルボン酸とフタル酸は、そ
の酸性度がほぼ等しい値を示す。しかしながら、実施例
１と比較例１を比べると、2,3−ナフタレンジカルボン
酸により表面処理した場合の方が、飽和磁化量σｓの保
持率が高く、磁性粉末の酸化による経時的劣化を抑えら
れることが判った。この事実から、処理剤としての酸性
度のみならず、芳香族環の有する溌水性が耐酸化性，耐
錆性に対して微妙に寄与していると考えられる。 The 2,3-naphthalenedicarboxylic acid and the phthalic acid show values in which the acidity is almost equal. However, comparing Example 1 with Comparative Example 1, the case where the surface treatment is performed with 2,3-naphthalenedicarboxylic acid has a higher retention of the saturation magnetization σs and suppresses the deterioration with time due to the oxidation of the magnetic powder. It turns out. From this fact, it is considered that not only the acidity of the treating agent but also the water repellency of the aromatic ring slightly contributes to oxidation resistance and rust resistance.
また、実施例１と実施例２、或いは実施例３と実施例
４をそれぞれ比較すると、実施例２や実施例４において
良好な結果が得られた。即ち、無水物は、処理剤として
の良好な酸性度を有しており、強磁性金属粒子の耐酸化
性の向上を図る上で好適な処理剤となる。Further, when Examples 1 and 2 were compared with each other, or Examples 3 and 4 were compared with each other, good results were obtained in Examples 2 and 4. That is, the anhydride has a good acidity as a treating agent and is a suitable treating agent for improving the oxidation resistance of the ferromagnetic metal particles.
実施例５ 本実施例においては、上記実施例１において使用した
強磁性金属粒子Ａと形状の異なる強磁性金属粒子Ｂを用
い、その他は実施例１と同様にして処理粉末を得た。Example 5 In this example, a treated powder was obtained in the same manner as in Example 1 except that ferromagnetic metal particles B having a different shape from the ferromagnetic metal particles A used in Example 1 were used.
比較例２ 上記実施例５において使用した2,3−ナフタレンジカ
ルボン酸をフタル酸に代えて、その他は上記実施例５と
同様にして処理粉末を得た。Comparative Example 2 A treated powder was obtained in the same manner as in Example 5 except that 2,3-naphthalenedicarboxylic acid used in Example 5 was replaced with phthalic acid.
上記実施例５及び比較例２において得られた処理粉末
について、真空乾燥後、未処理の強磁性金属粒子ととも
に抗磁力Hc,飽和磁化量σｓを測定した後、上述の恒温
恒湿槽中における条件よりも厳しい条件にして磁気特性
の経時変化を調べた。The treated powders obtained in Example 5 and Comparative Example 2 were vacuum-dried, and the coercive force Hc and the saturation magnetization σs were measured together with the untreated ferromagnetic metal particles. The change over time in the magnetic properties was examined under more severe conditions.
即ち、湿度90％、温度60℃に保持した恒温恒湿槽中
で、２週間放置した後、抗磁力Hc,飽和磁化量σｓを測
定して、飽和磁化量σｓの保持率を求めた。That is, after being left for two weeks in a thermo-hygrostat kept at a humidity of 90% and a temperature of 60 ° C., the coercive force Hc and the saturation magnetization σs were measured to determine the retention of the saturation magnetization σs.
この結果を第２表に示す。 Table 2 shows the results.
この結果から、比較例２においては、抗磁力Hc,飽和
磁化量σｓが著しく低下したにも係わらず、実施例５に
おいては、優れた経時安定性を示すことが明らかとされ
た。従って、処理剤として2,3−ナフタレンジカルボン
酸を用いることにより、耐酸化性，耐錆性が著しく向上
する。 From these results, it was clarified that in Comparative Example 2, excellent temporal stability was exhibited in Example 5, even though the coercive force Hc and the saturation magnetization σs were significantly reduced. Therefore, by using 2,3-naphthalenedicarboxylic acid as a treating agent, oxidation resistance and rust resistance are significantly improved.
上述のように、本発明では、強磁性金属粒子の表面を
2,3−ナフタレンジカルボン酸又はその無水物、1,8−ナ
フタレンジカルボン酸又はその無水物により表面処理し
ているので、強磁性金属粒子の酸化が防止され、耐酸化
性に優れた強磁性金属粒子を提供することができる。As described above, in the present invention, the surface of the ferromagnetic metal particles is
Surface treatment with 2,3-naphthalenedicarboxylic acid or its anhydride, 1,8-naphthalenedicarboxylic acid or its anhydride prevents oxidation of ferromagnetic metal particles and ferromagnetic metal with excellent oxidation resistance Particles can be provided.
また、本発明の磁気記録媒体用強磁性金属粒子は良好
な耐酸化性を有しているので、この強磁性金属粒子を磁
気記録媒体の磁性塗料に内添される磁性粉末として用い
れば、磁気特性の経時安定性，保存安定性に優れた高品
位な磁気記録媒体を製造することができる。Further, since the ferromagnetic metal particles for a magnetic recording medium of the present invention have good oxidation resistance, if these ferromagnetic metal particles are used as a magnetic powder to be added to a magnetic paint of a magnetic recording medium, the magnetic properties can be improved. It is possible to manufacture a high-quality magnetic recording medium having excellent storage stability and storage stability over time.
───────────────────────────────────────────────────── フロントページの続き (56)参考文献 特開 昭61−48503（ＪＰ，Ａ) 特開 平４−6619（ＪＰ，Ａ) 特開 平２−143404（ＪＰ，Ａ) 特公 平６−23402（ＪＰ，Ｂ２) 特公 平５−70207（ＪＰ，Ｂ２) 特公 昭56−42641（ＪＰ，Ｂ２) (58)調査した分野(Int.Cl.6，ＤＢ名) B22F 1/02 G11B 5/712 H01F 1/06 C09D 5/23 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-61-48503 (JP, A) JP-A-4-6619 (JP, A) JP-A-2-143404 (JP, A) 23402 (JP, B2) JP 5-70207 (JP, B2) JP 56-42641 (JP, B2) (58) Fields investigated (Int. Cl. 6 , DB name) B22F 1/02 G11B 5 / 712 H01F 1/06 C09D 5/23
Claims (2)
粒子よりなり、 2,3−ナフタレンジカルボン酸又はその無水物で表面処
理されたことを特徴とする磁気記録媒体用強磁性金属粒
子。1. Ferromagnetic metal particles for a magnetic recording medium, comprising fine particles of a ferromagnetic metal material or a ferromagnetic alloy material, which are surface-treated with 2,3-naphthalenedicarboxylic acid or an anhydride thereof.
粒子よりなり、 1,8−ナフタレンジカルボン酸又はその無水物で表面処
理されたことを特徴とする磁気記録媒体用強磁性金属粒
子。2. A ferromagnetic metal particle for a magnetic recording medium, comprising fine particles of a ferromagnetic metal material or a ferromagnetic alloy material, the surface of which is treated with 1,8-naphthalenedicarboxylic acid or an anhydride thereof.
Priority Applications (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2247333A JP2940117B2 (en) | 1990-09-19 | 1990-09-19 | Ferromagnetic metal particles for magnetic recording media |
| EP91113873A EP0472145A1 (en) | 1990-08-20 | 1991-08-19 | Ferromagnetic metal particles and magnetic recording medium containing them |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2247333A JP2940117B2 (en) | 1990-09-19 | 1990-09-19 | Ferromagnetic metal particles for magnetic recording media |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH04128303A JPH04128303A (en) | 1992-04-28 |
| JP2940117B2 true JP2940117B2 (en) | 1999-08-25 |
Family
ID=17161849
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2247333A Expired - Fee Related JP2940117B2 (en) | 1990-08-20 | 1990-09-19 | Ferromagnetic metal particles for magnetic recording media |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2940117B2 (en) |
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| KR100572245B1 (en) * | 2003-11-05 | 2006-04-19 | 한국기계연구원 | Manufacturing method of nano iron powder with polymer coating layer |
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