JPH031503A - Magnetic powder and magnetic recording medium using same - Google Patents
Magnetic powder and magnetic recording medium using sameInfo
- Publication number
- JPH031503A JPH031503A JP1135281A JP13528189A JPH031503A JP H031503 A JPH031503 A JP H031503A JP 1135281 A JP1135281 A JP 1135281A JP 13528189 A JP13528189 A JP 13528189A JP H031503 A JPH031503 A JP H031503A
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- powder
- coating
- iron 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.)
- Pending
Links
- 239000006247 magnetic powder Substances 0.000 title claims abstract description 46
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 33
- 239000011248 coating agent Substances 0.000 claims abstract description 27
- 238000000576 coating method Methods 0.000 claims abstract description 27
- 239000011230 binding agent Substances 0.000 claims abstract description 17
- 150000003377 silicon compounds Chemical class 0.000 claims abstract description 12
- 125000000524 functional group Chemical group 0.000 claims abstract description 10
- 229910052710 silicon Inorganic materials 0.000 claims abstract description 4
- 239000010703 silicon Substances 0.000 claims abstract description 4
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 claims abstract 2
- 150000001339 alkali metal compounds Chemical class 0.000 claims description 11
- 230000002378 acidificating effect Effects 0.000 claims description 8
- 239000002585 base Substances 0.000 claims description 8
- 229910052783 alkali metal Inorganic materials 0.000 claims description 3
- 150000001340 alkali metals Chemical class 0.000 claims description 3
- 230000005415 magnetization Effects 0.000 abstract description 15
- 229910052751 metal Inorganic materials 0.000 abstract description 13
- 239000002184 metal Substances 0.000 abstract description 13
- 238000006243 chemical reaction Methods 0.000 abstract description 9
- 150000002736 metal compounds Chemical class 0.000 abstract 3
- 239000002253 acid Substances 0.000 abstract 1
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 description 22
- 239000000843 powder Substances 0.000 description 8
- RMAQACBXLXPBSY-UHFFFAOYSA-N silicic acid Chemical compound O[Si](O)(O)O RMAQACBXLXPBSY-UHFFFAOYSA-N 0.000 description 7
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 6
- WMFOQBRAJBCJND-UHFFFAOYSA-M Lithium hydroxide Chemical compound [Li+].[OH-] WMFOQBRAJBCJND-UHFFFAOYSA-M 0.000 description 6
- YXFVVABEGXRONW-UHFFFAOYSA-N Toluene Chemical compound CC1=CC=CC=C1 YXFVVABEGXRONW-UHFFFAOYSA-N 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 5
- 150000008044 alkali metal hydroxides Chemical class 0.000 description 4
- 230000000052 comparative effect Effects 0.000 description 4
- 150000001875 compounds Chemical class 0.000 description 4
- 230000003301 hydrolyzing effect Effects 0.000 description 4
- 239000003973 paint Substances 0.000 description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 description 3
- XEKOWRVHYACXOJ-UHFFFAOYSA-N Ethyl acetate Chemical compound CCOC(C)=O XEKOWRVHYACXOJ-UHFFFAOYSA-N 0.000 description 3
- KFZMGEQAYNKOFK-UHFFFAOYSA-N Isopropanol Chemical compound CC(C)O KFZMGEQAYNKOFK-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
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical group OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 3
- KWYUFKZDYYNOTN-UHFFFAOYSA-M Potassium hydroxide Chemical compound [OH-].[K+] KWYUFKZDYYNOTN-UHFFFAOYSA-M 0.000 description 3
- HEMHJVSKTPXQMS-UHFFFAOYSA-M Sodium hydroxide Chemical compound [OH-].[Na+] HEMHJVSKTPXQMS-UHFFFAOYSA-M 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 238000004519 manufacturing process Methods 0.000 description 3
- 239000002904 solvent Substances 0.000 description 3
- IAZDPXIOMUYVGZ-UHFFFAOYSA-N Dimethylsulphoxide Chemical compound CS(C)=O IAZDPXIOMUYVGZ-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- WYURNTSHIVDZCO-UHFFFAOYSA-N Tetrahydrofuran Chemical compound C1CCOC1 WYURNTSHIVDZCO-UHFFFAOYSA-N 0.000 description 2
- 239000000654 additive Substances 0.000 description 2
- 230000015572 biosynthetic process Effects 0.000 description 2
- 125000002843 carboxylic acid group Chemical group 0.000 description 2
- 238000007796 conventional method Methods 0.000 description 2
- 230000007797 corrosion Effects 0.000 description 2
- 238000005260 corrosion Methods 0.000 description 2
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910052744 lithium Inorganic materials 0.000 description 2
- 238000000034 method Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 239000003960 organic solvent Substances 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- 229920006267 polyester film Polymers 0.000 description 2
- 229920005989 resin Polymers 0.000 description 2
- 239000011347 resin Substances 0.000 description 2
- 229910052708 sodium Inorganic materials 0.000 description 2
- 239000011734 sodium Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229920002554 vinyl polymer Polymers 0.000 description 2
- RYHBNJHYFVUHQT-UHFFFAOYSA-N 1,4-Dioxane Chemical compound C1COCCO1 RYHBNJHYFVUHQT-UHFFFAOYSA-N 0.000 description 1
- DEXFNLNNUZKHNO-UHFFFAOYSA-N 6-[3-[4-[2-(2,3-dihydro-1H-inden-2-ylamino)pyrimidin-5-yl]piperidin-1-yl]-3-oxopropyl]-3H-1,3-benzoxazol-2-one Chemical compound C1C(CC2=CC=CC=C12)NC1=NC=C(C=N1)C1CCN(CC1)C(CCC1=CC2=C(NC(O2)=O)C=C1)=O DEXFNLNNUZKHNO-UHFFFAOYSA-N 0.000 description 1
- DKPFZGUDAPQIHT-UHFFFAOYSA-N Butyl acetate Natural products CCCCOC(C)=O DKPFZGUDAPQIHT-UHFFFAOYSA-N 0.000 description 1
- DGAQECJNVWCQMB-PUAWFVPOSA-M Ilexoside XXIX Chemical compound C[C@@H]1CC[C@@]2(CC[C@@]3(C(=CC[C@H]4[C@]3(CC[C@@H]5[C@@]4(CC[C@@H](C5(C)C)OS(=O)(=O)[O-])C)C)[C@@H]2[C@]1(C)O)C)C(=O)O[C@H]6[C@@H]([C@H]([C@@H]([C@H](O6)CO)O)O)O.[Na+] DGAQECJNVWCQMB-PUAWFVPOSA-M 0.000 description 1
- WHXSMMKQMYFTQS-UHFFFAOYSA-N Lithium Chemical compound [Li] WHXSMMKQMYFTQS-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
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229920002433 Vinyl chloride-vinyl acetate copolymer Polymers 0.000 description 1
- 239000003082 abrasive agent Substances 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 239000005456 alcohol based solvent Substances 0.000 description 1
- 229910001854 alkali hydroxide Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 239000002216 antistatic agent Substances 0.000 description 1
- 150000004945 aromatic hydrocarbons Chemical class 0.000 description 1
- 238000003490 calendering Methods 0.000 description 1
- 239000012461 cellulose resin Substances 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 239000003431 cross linking reagent Substances 0.000 description 1
- 239000002270 dispersing agent Substances 0.000 description 1
- 239000003759 ester based solvent Substances 0.000 description 1
- 239000004210 ether based solvent Substances 0.000 description 1
- 239000000945 filler Substances 0.000 description 1
- FUZZWVXGSFPDMH-UHFFFAOYSA-N hexanoic acid Chemical compound CCCCCC(O)=O FUZZWVXGSFPDMH-UHFFFAOYSA-N 0.000 description 1
- XLYOFNOQVPJJNP-UHFFFAOYSA-M hydroxide Chemical compound [OH-] XLYOFNOQVPJJNP-UHFFFAOYSA-M 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000005453 ketone based solvent Substances 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 238000005259 measurement Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000002156 mixing Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 150000003961 organosilicon compounds Chemical class 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
- 229920001228 polyisocyanate Polymers 0.000 description 1
- 239000005056 polyisocyanate Substances 0.000 description 1
- 229920005749 polyurethane resin Polymers 0.000 description 1
- 238000012805 post-processing Methods 0.000 description 1
- 238000003847 radiation curing Methods 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 238000003756 stirring Methods 0.000 description 1
- 125000000542 sulfonic acid group Chemical group 0.000 description 1
- 150000003462 sulfoxides Chemical class 0.000 description 1
- 238000004381 surface treatment Methods 0.000 description 1
- TUNFSRHWOTWDNC-HKGQFRNVSA-N tetradecanoic acid Chemical compound CCCCCCCCCCCCC[14C](O)=O TUNFSRHWOTWDNC-HKGQFRNVSA-N 0.000 description 1
- YLQBMQCUIZJEEH-UHFFFAOYSA-N tetrahydrofuran Natural products C=1C=COC=1 YLQBMQCUIZJEEH-UHFFFAOYSA-N 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
この発明は、磁気記録素子として有用な磁性粉末と、こ
の磁性粉末を用いた磁気テープや磁気ディスクなどの磁
気記録媒体に関する。DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a magnetic powder useful as a magnetic recording element and a magnetic recording medium such as a magnetic tape or a magnetic disk using this magnetic powder.
磁気記録媒体の記録素子のひとつとして、保磁力や飽和
磁化の高い金属鉄粉末が知られている。Metallic iron powder with high coercive force and saturation magnetization is known as one of the recording elements of magnetic recording media.
この磁性粉末はこれを分散結着するバインダとともに非
磁性支持体上に塗着することによって磁性層を構成させ
、磁気テープや磁気ディスクなどの磁気記録媒体とされ
る。This magnetic powder forms a magnetic layer by coating it on a non-magnetic support together with a binder for dispersing and binding it, and is used as a magnetic recording medium such as a magnetic tape or a magnetic disk.
従来より、この種の磁気記録媒体の耐久性を改良するた
めに、磁性粉末を分散結着するバインダとして分子内に
リン酸基、カルボン酸基などの酸性の官能基を有するも
のを用いる一方、磁性粉末の表面にアルカリ金属化合物
の被膜を形成しておき、これと上記官能基との相互作用
によってバインダに対する磁性粉末の結着力を強め、磁
性層の機械的強度を高めることがよく行われている。Conventionally, in order to improve the durability of this type of magnetic recording medium, binders having acidic functional groups such as phosphoric acid groups and carboxylic acid groups in their molecules have been used as binders for dispersing and binding magnetic powder. It is a common practice to form a film of an alkali metal compound on the surface of the magnetic powder, and the interaction between this film and the above-mentioned functional groups strengthens the adhesion of the magnetic powder to the binder, thereby increasing the mechanical strength of the magnetic layer. There is.
しかるに、上記従来の改良手段によると、金属鉄粉末の
表面に被膜状に設けられるアルカリ金属化合物の水分吸
収作用により、粉末表面が高湿度状態となって腐食しや
すくなるためか、金属鉄粉末の飽和磁化が大きく低下し
、電磁変換特性やさらに耐久性の面で問題があった。However, according to the above-mentioned conventional improvement means, the moisture absorption effect of the alkali metal compound provided in the form of a film on the surface of the metallic iron powder causes the powder surface to be in a high humidity state and become susceptible to corrosion. Saturation magnetization decreased significantly, causing problems in electromagnetic conversion characteristics and durability.
この発明は、上述の事情に照らし、高湿度状態において
も飽和磁化の経口的な低下が抑えられた金属鉄系磁性粉
末を提供するとともに、これを用いて耐久性および電磁
変換特性にすぐれた磁気記録媒体を得ることを目的とし
ている。In light of the above-mentioned circumstances, the present invention provides a metallic iron-based magnetic powder that suppresses the decrease in saturation magnetization even under high humidity conditions, and uses the same to provide a magnetic powder with excellent durability and electromagnetic conversion characteristics. The purpose is to obtain a recording medium.
この発明者らは、上記の目的を達成するために鋭意検討
した結果、金属鉄粉末の表面にあらかじめ特定の下地処
理を施したのちにアルカリ金属化合物の被膜を形成する
ようにすると、飽和磁化の経口的安定性にすぐれた磁性
粉末が得られ、この磁性粉末と分子内に酸性の官能基を
有するバインダとを用いて磁性層を形成した磁気記録媒
体によると、耐久性および電磁変換特性の両面ですぐれ
た性能を発揮させうるものであることを知り、この発明
をなすに至った。As a result of intensive studies to achieve the above object, the inventors found that by forming a coating of an alkali metal compound on the surface of metallic iron powder after applying a specific surface treatment in advance, the saturation magnetization could be reduced. A magnetic powder with excellent oral stability is obtained, and a magnetic recording medium in which a magnetic layer is formed using this magnetic powder and a binder having an acidic functional group in the molecule has excellent durability and electromagnetic conversion characteristics. After discovering that it can exhibit excellent performance, he came up with this invention.
すなわち、この発明の第１は、金属鉄粉末の表面にケイ
素化合物からなる下地被膜を介してアルカリ金属化合物
の被膜が形成されてなる磁性粉末に係るものである。That is, the first aspect of the present invention relates to a magnetic powder in which a coating of an alkali metal compound is formed on the surface of a metallic iron powder through an underlying coating made of a silicon compound.
また、この発明の第２は、非磁性支持体上に上記第１の
発明に係る特定の磁性粉末と酸性の官能基を有するバイ
ンダとを含む磁性層が設けられてなる磁気記録媒体に係
るものである。A second aspect of the present invention relates to a magnetic recording medium in which a magnetic layer containing the specific magnetic powder according to the first aspect and a binder having an acidic functional group is provided on a non-magnetic support. It is.
この発明の磁性粉末において、その表面に所要の被膜を
形成するべき金属鉄粉末としては、平均粒子径が通常０
．１〜１μｍ、平均軸比（平均長軸径／平均短軸径）が
通常５〜１５程度の針状の磁性粉末が好ましく用いられ
る。この金属鉄粉末は、金属鉄のみからなるもののほか
、金属鉄と少量のコバルト、ニッケルなどの他の金属と
の合金であってもよい。保磁力は一般に５００〜２．０
００エルステツド、飽和磁化は５０〜２００ ｅ ｍ
ｕ ／ ｇ程度である。In the magnetic powder of the present invention, the metal iron powder that should form the required coating on its surface usually has an average particle diameter of 0.
．． Acicular magnetic powder having a diameter of 1 to 1 μm and an average axial ratio (average major axis diameter/average minor axis diameter) of usually about 5 to 15 is preferably used. This metallic iron powder may be composed only of metallic iron, or may be an alloy of metallic iron and a small amount of other metals such as cobalt and nickel. Coercive force is generally 500 to 2.0
00 oersted, saturation magnetization is 50-200 em
It is about u/g.
この発明においては、このような金属鉄粉末の表面にま
ずケイ素化合物からなる下地被膜を形成する。この下地
被膜の形成は、たとえば金属鉄粉末をエタノールなどの
液中に分散させ、これにテトラアルコキシシランなどの
有機ケイ素化合物を加えたのち、この化合物を加水分解
して、上記粉末の表面にケイ素の水酸化物の被膜を形成
するなどの方法により、行うことができる。In this invention, a base film made of a silicon compound is first formed on the surface of such metallic iron powder. The formation of this base film involves, for example, dispersing metallic iron powder in a liquid such as ethanol, adding an organosilicon compound such as tetraalkoxysilane to this, and then hydrolyzing this compound to form silicon on the surface of the powder. This can be done by a method such as forming a hydroxide film.
なお、このようなケイ素化合物の被膜を磁性粉末の表面
に形成して、この粉末のバインダ中での分散性などを高
めることは、既に公知の技術である。しかし、この発明
のように、アルカリ金属化合物の被膜を形成するにあた
って、その下地処理としてケイ素化合物の被膜を形成し
、これにより金属鉄粉末の経日的な飽和磁化の劣化を防
ぎ、これを記録素子とした磁気記録媒体の耐久性と電磁
変換特性とを共に高度に満足させることについては全く
知られていなかったことである。Note that it is already a known technique to form a film of such a silicon compound on the surface of magnetic powder to improve the dispersibility of this powder in a binder. However, in forming the alkali metal compound film as in this invention, a silicon compound film is formed as a base treatment, thereby preventing the deterioration of the saturation magnetization of the metal iron powder over time and recording this. It was completely unknown that a magnetic recording medium used as an element could satisfy both durability and electromagnetic conversion characteristics to a high degree.
ケイ素化合物からなる下地被膜の量としては、一般に金
属鉄粉末に対しケイ素基準で０．０５〜１０重量％、特
に好適には０．１〜５重量％となるようにするのがよい
。この量が過少では所期の効果が得られず、また過多と
なると飽和磁化などの磁気特性の低下がみられ、好まし
くない。The amount of the base coating made of the silicon compound is generally 0.05 to 10% by weight, particularly preferably 0.1 to 5% by weight based on silicon, based on the metal iron powder. If this amount is too small, the desired effect will not be obtained, and if it is too large, magnetic properties such as saturation magnetization will deteriorate, which is not preferable.
この発明においては、このようなケイ素化合物からなる
下地被膜を形成したのち、さらにこの上にアルカリ金属
化合物の被膜を形成して、磁気記録素子としての磁性粉
末を得る。ここで、アルカリ金属化合物の被膜の形成は
、たとえば上記の下地被膜を有する金属鉄粉末をエタノ
ールなどの液中に分散させ、これにＬｉ、Ｎａ、になど
のアルカリ金属のアルコラードなどの化合物を加えたの
ち、この化合物を加水分解して、上記粉末の表面にアル
カリ金属の水酸化物の被膜を形成するなどの方法により
、行うことができる。In the present invention, after forming a base coat made of such a silicon compound, a coat of an alkali metal compound is further formed thereon to obtain magnetic powder as a magnetic recording element. Here, the formation of the alkali metal compound coating is achieved by, for example, dispersing the metal iron powder having the above-mentioned base coating in a liquid such as ethanol, and adding a compound such as alcolade of an alkali metal such as Li, Na, or Afterwards, this compound can be hydrolyzed to form a film of alkali metal hydroxide on the surface of the powder.
このアルカリ金属化合物の被膜の量としては、一般に金
属鉄粉末に対しアルカリ金属基準でｏ、０１〜５重量％
、特に好適には０．０５〜１重量％となるようにするの
がよい。この量が過少では耐久性などの改善効果が得ら
れず、また過多となると飽和磁化などの磁気特性の低下
がみられ、好ましくない。The amount of the alkali metal compound coating is generally 0.01 to 5% by weight based on the alkali metal based on the metallic iron powder.
, particularly preferably from 0.05 to 1% by weight. If this amount is too small, the effect of improving durability etc. cannot be obtained, and if this amount is too large, a decrease in magnetic properties such as saturation magnetization will be observed, which is not preferable.
この発明の磁気記録媒体は、このような磁性粉末と酸性
の官能基を有するバインダとを含む磁性層がポリエステ
ルフィルムなどの非磁性支持体の上に設けられてなるも
のであり、常法に準じて製造することができる。たとえ
ば、上記の磁性粉末と上記のバインダと必要に応じて配
合される各種の添加剤とを有機溶媒中に添加混合して磁
性塗料を調製し、この塗料を非磁性支持体上に塗布、乾
燥して所要厚さの磁性層を形成したのち、カレンダー加
工などの適当な後処理を施し、所要の磁気記録媒体の形
状とすればよい。The magnetic recording medium of the present invention has a magnetic layer containing such magnetic powder and a binder having an acidic functional group provided on a non-magnetic support such as a polyester film, and is prepared by a conventional method. It can be manufactured using For example, a magnetic paint is prepared by adding and mixing the above-mentioned magnetic powder, the above-mentioned binder, and various additives blended as necessary in an organic solvent, and this paint is applied onto a non-magnetic support and dried. After forming a magnetic layer with a desired thickness, appropriate post-processing such as calendering may be performed to form the desired shape of the magnetic recording medium.
上記のバインダとしては、塩化ビニル−酢酸ビニル系共
重合体、ポリビニルブチラール系樹脂、繊維素系樹脂、
ポリウレタン系樹脂、ポリエステル系樹脂、架橋剤とし
てのポリイソシアネート化合物、放射線硬化型樹脂など
、従来より磁気記録媒体の磁性層用のバインダとして知
られるものをいずれも単独でまたは二種以上を混合して
使用できる。ただし、これらバインダの一部または全部
は、゛リン酸基、カルボン酸基、スルホン酸基などの酸
性の官能基を分子内に存するものであることが必要であ
る。Examples of the above binders include vinyl chloride-vinyl acetate copolymers, polyvinyl butyral resins, cellulose resins,
Polyurethane resins, polyester resins, polyisocyanate compounds as crosslinking agents, radiation curing resins, and other binders conventionally known as binders for magnetic layers of magnetic recording media can be used singly or in combination of two or more. Can be used. However, it is necessary that some or all of these binders contain an acidic functional group such as a phosphoric acid group, a carboxylic acid group, or a sulfonic acid group in the molecule.
有機溶剤としては、シクロヘキサノン、メチルエチルケ
トン、メチルイソブチルケトンなどのケトン系溶剤、酢
酸エチル、酢酸ブチルなどのエステル系溶剤、ベンゼン
、トルエン、キシレンなどの芳香族炭化水素系溶剤、イ
ソプロピルアルコールなどのアルコール系溶剤、ジメチ
ルホルムアミドなどの酸アミド系溶剤、ジメチルスルホ
キシドなどのスルホキシド系溶剤、テトラヒドロフラン
、ジオキサンなどのエーテル系溶剤など、使用するバイ
ンダを溶解するのに適した溶剤が特に制限されることな
く単独でまたは二種以上を混合して使用できる。Examples of organic solvents include ketone solvents such as cyclohexanone, methyl ethyl ketone, and methyl isobutyl ketone, ester solvents such as ethyl acetate and butyl acetate, aromatic hydrocarbon solvents such as benzene, toluene, and xylene, and alcohol solvents such as isopropyl alcohol. , acid amide solvents such as dimethylformamide, sulfoxide solvents such as dimethyl sulfoxide, and ether solvents such as tetrahydrofuran and dioxane. Can be used in combination with more than one species.
また、必要に応じて配合される添加剤としては、分散剤
、潤滑剤、研摩剤、帯電防止剤、充填剤などが挙げられ
る。Further, additives that may be added as necessary include dispersants, lubricants, abrasives, antistatic agents, fillers, and the like.
以上のように、この発明においては、金属鉄粉末の表面
にケイ素化合物の被膜を介してアルカリ金属化合物の被
膜を形成したことにより、飽和磁化の経口的安定性にす
ぐれた磁性粉末が得られ、この磁性粉末と酸性の官能基
を有するバインダとを含む磁性層を非磁性支持体上に設
けることにより、耐久性および電磁変換特性に共にすぐ
れた磁気記録媒体を得ることができる。As described above, in this invention, by forming a coating of an alkali metal compound on the surface of metallic iron powder via a coating of a silicon compound, a magnetic powder with excellent oral stability of saturation magnetization can be obtained. By providing a magnetic layer containing this magnetic powder and a binder having an acidic functional group on a nonmagnetic support, a magnetic recording medium with excellent durability and electromagnetic conversion characteristics can be obtained.
つぎに、この発明を実施例に基づいて具体的に説明する
。Next, the present invention will be specifically explained based on examples.
実施例１
平均粒子径０．２μｍ、平均軸比１０の針状の金属鉄粉
末１００ｇを、２βのエタノール中に分散させ、これに
７．５ｇのＳ ｉ （ＯＣｚ Ｈｓ ） ａを加え、
撹拌しながら６０℃まで昇温後、７．８ｇの水を徐々に
滴下してＳｔ （ＯＣｚ Ｈ５）４を加水分解し、金
属鉄粉末の表面にケイ素の水酸化物の被膜を形成した。Example 1 100 g of acicular metallic iron powder with an average particle diameter of 0.2 μm and an average axial ratio of 10 was dispersed in 2β ethanol, and 7.5 g of Si (OCz Hs ) a was added thereto.
After raising the temperature to 60° C. while stirring, 7.8 g of water was gradually added dropwise to hydrolyze St (OCz H5) 4 to form a silicon hydroxide film on the surface of the metal iron powder.
ついで、このようにして下地被膜を形成した金属鉄粉末
を含有するエタノール中に、さらに３００ｇのＬ ｉ
ＯＣ２Ｈ３の５重量％エタノール溶液を加え、６０℃を
保ったまま６３ｇの水を徐々に滴下してＬ ｉ ＯＣｔ
Ｈｓを加水分解し、リチウムの水酸化物の被膜を形成
した。この被膜形成後、８０℃で乾燥して、磁性粉末を
得た。Then, an additional 300 g of Li
A 5% by weight ethanol solution of OC2H3 was added, and 63g of water was gradually added dropwise while maintaining the temperature at 60°C to obtain Li OCt.
Hs was hydrolyzed to form a lithium hydroxide film. After forming this film, it was dried at 80°C to obtain magnetic powder.
つぎに、この磁性粉末１００重量部、リン酸基を含む塩
化ビニル−酢酸ビニル−ビニルアルコル共重合体１０．
５重量部、ミリスチン酸４重量部、トルエン１）０重量
部、メチルエチルケトン１００重量部の組成からなる磁
性塗料を常法により調製した。この塗料を厚さ１０μｍ
のポリエステルフィルム上に乾燥後の厚さが３μｍとな
るように塗布し、配向強度３．０００ガウスで配向処理
し、乾燥して、磁気テープを作製した。Next, 100 parts by weight of this magnetic powder and 10 parts by weight of a vinyl chloride-vinyl acetate-vinyl alcohol copolymer containing a phosphoric acid group were added.
A magnetic paint having a composition of 5 parts by weight, 4 parts by weight of myristic acid, 1) part by weight of toluene, and 100 parts by weight of methyl ethyl ketone was prepared by a conventional method. Apply this paint to a thickness of 10 μm.
The magnetic tape was coated onto a polyester film to have a dry thickness of 3 μm, subjected to orientation treatment at an orientation strength of 3.000 Gauss, and dried to produce a magnetic tape.
実施例２
実施例１の磁性粉末の製法におけるＬｉ０ＣｚＨ３の５
重量％エタノール溶液に代えて、１２０ｇのＮａ ＯＣ
２）（ｓの５重量％エタノール溶液を用いるとともに、
これを加水分解させるための水の量を１９ｇに変更した
以外は、実施例１と同様にして、ケイ素の水酸化物の被
膜上にナトリウムの水酸化物の被膜を有する磁性粉末を
得た。っぎに、この磁性粉末を用いて実施例１と同様に
して、磁気テープを作製した。Example 2 5 of Li0CzH3 in the method for producing magnetic powder of Example 1
120 g of Na OC instead of wt% ethanol solution
2) Using a 5% by weight ethanol solution of (s),
A magnetic powder having a sodium hydroxide coating on a silicon hydroxide coating was obtained in the same manner as in Example 1, except that the amount of water for hydrolyzing this was changed to 19 g. Next, a magnetic tape was produced in the same manner as in Example 1 using this magnetic powder.
実施例３
実施例１の磁性粉末の製法におけるＬｉ０Ｃ２Ｈ３の５
重量％エタノール溶液に代えて、８６ｇのＫＯＣ，Ｈ５
の５重量％エタノール溶液を用いるとともに、これを加
水分解させるための水の量を１２ｇに変更した以外は、
実施例１と同様にして、ケイ素の水酸化物の被膜上にカ
リウムの水酸化物の被膜を有する磁性粉末を得た。つぎ
に、この磁性粉末を用いて実施例１と同様にして、磁気
テープを作製した。Example 3 5 of Li0C2H3 in the method for producing magnetic powder of Example 1
86 g of KOC, H5 in place of the wt% ethanol solution
Except that a 5% by weight ethanol solution was used and the amount of water for hydrolyzing this was changed to 12 g.
In the same manner as in Example 1, a magnetic powder having a potassium hydroxide coating on a silicon hydroxide coating was obtained. Next, a magnetic tape was produced in the same manner as in Example 1 using this magnetic powder.
実施例４
実施例１の磁性粉末の製法におけるＬｉ０ＣｚＨ１の５
重量％エタノール溶液に代えて、１５０ｇのｌ、１０ｃ
２Ｈｓの５重量％エタノール溶液と６０ｇのＮ ａ Ｏ
Ｃｚ Ｈｓの５重量％エタノール溶液との混合液を用い
るとともに、これを加水分解させるための水の量を４１
ｇに変更した以外は、実施例１と同様にして、ケイ素の
水酸化物の被膜上にリチウムとナトリウムとの混合アル
カリの水酸化物の被膜を有する磁性粉末を得た。つぎに
、この磁性粉末を用いて実施例１と同様にして、磁気テ
ープを作製した。Example 4 5 of Li0CzH1 in the method for producing magnetic powder of Example 1
Instead of wt% ethanol solution, 150g l, 10c
5 wt% ethanol solution of 2Hs and 60 g NaO
A mixture of Cz Hs and a 5% by weight ethanol solution was used, and the amount of water for hydrolyzing this was 41% by weight.
A magnetic powder having a coating of mixed alkali hydroxide of lithium and sodium on a coating of silicon hydroxide was obtained in the same manner as in Example 1, except that the powder was changed to g. Next, a magnetic tape was produced in the same manner as in Example 1 using this magnetic powder.
参考例１
未処理の金属鉄粉末をそのまま記録素子としての磁性粉
末とし、この粉末を用いて実施例１と同様にして、磁気
テープを作製した。Reference Example 1 An untreated metallic iron powder was used as a magnetic powder as a recording element, and a magnetic tape was produced using this powder in the same manner as in Example 1.
参考例２
金属鉄粉末の表面にケイ素の水酸化物の被膜を形成した
だけで、この上にリチウムの水酸化物の被膜を形成しな
かった以外は、実施例１と同様にして磁性粉末を得、こ
の粉末を用いて実施例１と同様にして、磁気テープを作
製した。Reference Example 2 Magnetic powder was prepared in the same manner as in Example 1, except that a silicon hydroxide film was only formed on the surface of the metal iron powder, and a lithium hydroxide film was not formed thereon. A magnetic tape was produced in the same manner as in Example 1 using this powder.
比較例１〜４
下地被膜としてのケイ素の水酸化物の被膜を形成せず、
金属鉄粉末の表面に直接アルカリ金属の水酸化物の被膜
を形成した以外は、それぞれ実施例１〜４と同様にして
、４種の磁性粉末を得、これらの磁性粉末を用いて実施
例１と同様にして、４種の磁気テープを作製した。Comparative Examples 1 to 4 No silicon hydroxide film was formed as the base film,
Four types of magnetic powders were obtained in the same manner as in Examples 1 to 4, except that a film of alkali metal hydroxide was directly formed on the surface of the metal iron powder, and Example 1 was prepared using these magnetic powders. Four types of magnetic tapes were produced in the same manner as above.
以上の実施例、参考例および比較例の各磁性粉末につき
、磁気特性として保磁力〔Ｈｃ〕、飽和磁化〔δＳ〕を
測定し、また耐食性試験として６０℃、９０％ＲＨで１
週間放置したときの飽和磁化を調べ、初期の飽和磁化に
対する劣化率を求めた。また、上記の実施例、参考例お
よび比較例の各磁気テープにつき、耐久性試験として低
温（−５℃）でのスチル特性、電磁変換特性としてＲＦ
比出力調べた。これらの試験結果をまとめて、つぎの第
１表に示す。For each of the magnetic powders of the above examples, reference examples, and comparative examples, the coercive force [Hc] and saturation magnetization [δS] were measured as magnetic properties, and the corrosion resistance test was conducted at 60°C and 90%RH.
The saturation magnetization when left for a week was examined, and the deterioration rate relative to the initial saturation magnetization was determined. In addition, for each of the magnetic tapes of the above Examples, Reference Examples, and Comparative Examples, still characteristics at low temperature (-5°C) were tested for durability, and RF was tested for electromagnetic conversion characteristics.
I checked the specific output. The results of these tests are summarized in Table 1 below.
なお、上記のスチル特性は、市販ＶＴＲを用い、温度−
５℃の環境下でスチールモールドにおいて出力が初期出
力の２／３に低下するまでの時間（分）を測定した。ま
た、ＲＦ比出力、５ Ｍ Ｈｚの信号を一定レベルで記
録することにより測定し、この測定結果を参考例１の磁
気テープを基準（ＯｄＢ）とした相対値にて示した。Note that the above still characteristics were determined using a commercially available VTR, and the temperature -
The time (minutes) until the output decreased to 2/3 of the initial output was measured in a steel mold in an environment of 5°C. Further, the RF specific output was measured by recording a 5 MHz signal at a constant level, and the measurement results are shown as relative values with the magnetic tape of Reference Example 1 as a reference (OdB).
第１表
上表の結果から、この発明の磁性粉末（実施例１〜４）
は、飽和磁化の経口的安定性にすぐれており、この粉末
と酸性の官能基を有するバインダとを含む磁性層を非磁
性支持体上に設けてなるこの発明の磁気テープ（実施例
１〜４）は、耐久性および電磁変換特性に共にすぐれて
いる。From the results shown in Table 1, the magnetic powder of the present invention (Examples 1 to 4)
has excellent oral stability of saturation magnetization, and the magnetic tape of the present invention (Examples 1 to 4) is prepared by providing a magnetic layer containing this powder and a binder having an acidic functional group on a non-magnetic support. ) has excellent durability and electromagnetic conversion characteristics.
これに対し、金属鉄粉末の表面に直接アルカリ金属の水
酸化物の被膜を形成した磁性粉末（比較例１〜４）は、
飽和磁化の経口的安定性に劣っており、これを用いた磁
気テープは電磁変換特性に劣り、また耐久性の改善効果
も不充分である。また、金属鉄粉末の表面にケイ素の水
酸化物の被膜のみを形成した参考例２の磁性粉末を記録
素子として用いた磁気テープでは、主に耐久性の改善効
果に乏しいものであることがわかる。On the other hand, magnetic powders (Comparative Examples 1 to 4) in which a film of alkali metal hydroxide was directly formed on the surface of metallic iron powder,
It has poor oral stability of saturation magnetization, and magnetic tapes using it have poor electromagnetic conversion characteristics, and the effect of improving durability is also insufficient. Furthermore, it can be seen that the magnetic tape using the magnetic powder of Reference Example 2, in which only a silicon hydroxide film was formed on the surface of the metallic iron powder, as a recording element mainly lacked the effect of improving durability. .
特許出願人 日立マクセル株式会社Patent applicant: Hitachi Maxell, Ltd.
Claims (3)
膜を介してアルカリ金属化合物の被膜が形成されてなる
磁性粉末。(1) Magnetic powder in which a coating of an alkali metal compound is formed on the surface of metallic iron powder with an underlying coating made of a silicon compound interposed therebetween.
に対しケイ素基準で０．０５〜１０重量％、アルカリ金
属化合物の被膜の量が金属鉄粉末に対しアルカリ金属基
準で０．０１〜５重量％である請求項（１）に記載の磁
性粉末。(2) The amount of the base coating made of a silicon compound is 0.05 to 10% by weight based on silicon based on the metallic iron powder, and the amount of the coating of an alkali metal compound is 0.01 to 5% by weight based on the alkali metal based on the metallic iron powder. The magnetic powder according to claim 1, which is % by weight.
載の磁性粉末と酸性の官能基を有するバインダとを含む
磁性層が設けられてなる磁気記録媒体。(3) A magnetic recording medium comprising a magnetic layer containing the magnetic powder according to claim (1) or (2) and a binder having an acidic functional group on a non-magnetic support.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1135281A JPH031503A (en) | 1989-05-29 | 1989-05-29 | Magnetic powder and magnetic recording medium using same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP1135281A JPH031503A (en) | 1989-05-29 | 1989-05-29 | Magnetic powder and magnetic recording medium using same |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPH031503A true JPH031503A (en) | 1991-01-08 |
Family
ID=15148038
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP1135281A Pending JPH031503A (en) | 1989-05-29 | 1989-05-29 | Magnetic powder and magnetic recording medium using same |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH031503A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010156054A (en) * | 2004-02-24 | 2010-07-15 | Hitachi Metals Ltd | Metallic microparticle, manufacturing method therefor, and magnetic bead |
| CN104250690A (en) * | 2014-07-21 | 2014-12-31 | 新疆金特钢铁股份有限公司 | Iron powder thawing store |
-
1989
- 1989-05-29 JP JP1135281A patent/JPH031503A/en active Pending
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2010156054A (en) * | 2004-02-24 | 2010-07-15 | Hitachi Metals Ltd | Metallic microparticle, manufacturing method therefor, and magnetic bead |
| CN104250690A (en) * | 2014-07-21 | 2014-12-31 | 新疆金特钢铁股份有限公司 | Iron powder thawing store |
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