JPH0222447B2 - - Google Patents
Info
- Publication number
- JPH0222447B2 JPH0222447B2 JP57087752A JP8775282A JPH0222447B2 JP H0222447 B2 JPH0222447 B2 JP H0222447B2 JP 57087752 A JP57087752 A JP 57087752A JP 8775282 A JP8775282 A JP 8775282A JP H0222447 B2 JPH0222447 B2 JP H0222447B2
- Authority
- JP
- Japan
- Prior art keywords
- magnetic
- powder
- binder
- dispersibility
- coupling agent
- 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 - Lifetime
Links
- 230000005291 magnetic effect Effects 0.000 claims description 59
- 239000011230 binding agent Substances 0.000 claims description 29
- 239000000843 powder Substances 0.000 claims description 24
- 238000000576 coating method Methods 0.000 claims description 20
- 239000006087 Silane Coupling Agent Substances 0.000 claims description 19
- 239000011248 coating agent Substances 0.000 claims description 18
- 230000005294 ferromagnetic effect Effects 0.000 claims description 15
- 125000003277 amino group Chemical group 0.000 claims description 14
- 239000000463 material Substances 0.000 claims description 8
- 238000004519 manufacturing process Methods 0.000 claims description 7
- 239000000758 substrate Substances 0.000 claims description 7
- 239000004593 Epoxy Substances 0.000 claims description 6
- 150000001875 compounds Chemical class 0.000 claims description 6
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 claims description 4
- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 claims description 2
- 239000006247 magnetic powder Substances 0.000 description 32
- 239000003973 paint Substances 0.000 description 23
- 239000006185 dispersion Substances 0.000 description 15
- 229910001566 austenite Inorganic materials 0.000 description 10
- XEEYBQQBJWHFJM-UHFFFAOYSA-N iron Substances [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 9
- 239000002245 particle Substances 0.000 description 9
- 238000011282 treatment Methods 0.000 description 9
- -1 alkyl imidazoline compound Chemical class 0.000 description 8
- 238000000034 method Methods 0.000 description 8
- 239000004094 surface-active agent Substances 0.000 description 7
- ZWEHNKRNPOVVGH-UHFFFAOYSA-N 2-Butanone Chemical compound CCC(C)=O ZWEHNKRNPOVVGH-UHFFFAOYSA-N 0.000 description 6
- 229920005989 resin Polymers 0.000 description 6
- 239000011347 resin Substances 0.000 description 6
- 239000002904 solvent Substances 0.000 description 6
- IISBACLAFKSPIT-UHFFFAOYSA-N bisphenol A Chemical compound C=1C=C(O)C=CC=1C(C)(C)C1=CC=C(O)C=C1 IISBACLAFKSPIT-UHFFFAOYSA-N 0.000 description 5
- 238000006243 chemical reaction Methods 0.000 description 5
- 239000010410 layer Substances 0.000 description 5
- 229910052751 metal Inorganic materials 0.000 description 5
- 239000002184 metal Substances 0.000 description 5
- WNLRTRBMVRJNCN-UHFFFAOYSA-N adipic acid Chemical compound OC(=O)CCCCC(O)=O WNLRTRBMVRJNCN-UHFFFAOYSA-N 0.000 description 4
- 238000001035 drying Methods 0.000 description 4
- 239000003960 organic solvent Substances 0.000 description 4
- 229920005749 polyurethane resin Polymers 0.000 description 4
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 3
- NTIZESTWPVYFNL-UHFFFAOYSA-N Methyl isobutyl ketone Chemical compound CC(C)CC(C)=O NTIZESTWPVYFNL-UHFFFAOYSA-N 0.000 description 3
- UIHCLUNTQKBZGK-UHFFFAOYSA-N Methyl isobutyl ketone Natural products CCC(C)C(C)=O UIHCLUNTQKBZGK-UHFFFAOYSA-N 0.000 description 3
- 229920002433 Vinyl chloride-vinyl acetate copolymer Polymers 0.000 description 3
- 230000002776 aggregation Effects 0.000 description 3
- 239000003795 chemical substances by application Substances 0.000 description 3
- 230000007423 decrease Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 150000002148 esters Chemical class 0.000 description 3
- 230000000704 physical effect Effects 0.000 description 3
- 229920000728 polyester Polymers 0.000 description 3
- 238000001179 sorption measurement Methods 0.000 description 3
- 238000004381 surface treatment Methods 0.000 description 3
- 239000010936 titanium Substances 0.000 description 3
- 229910052719 titanium Inorganic materials 0.000 description 3
- 229920000742 Cotton Polymers 0.000 description 2
- BRLQWZUYTZBJKN-UHFFFAOYSA-N Epichlorohydrin Chemical compound ClCC1CO1 BRLQWZUYTZBJKN-UHFFFAOYSA-N 0.000 description 2
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 2
- 239000001361 adipic acid Substances 0.000 description 2
- 235000011037 adipic acid Nutrition 0.000 description 2
- 238000004220 aggregation Methods 0.000 description 2
- 238000009835 boiling Methods 0.000 description 2
- WERYXYBDKMZEQL-UHFFFAOYSA-N butane-1,4-diol Chemical compound OCCCCO WERYXYBDKMZEQL-UHFFFAOYSA-N 0.000 description 2
- 239000007795 chemical reaction product Substances 0.000 description 2
- 239000010941 cobalt Substances 0.000 description 2
- 229910017052 cobalt Inorganic materials 0.000 description 2
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 239000007822 coupling agent Substances 0.000 description 2
- JHIVVAPYMSGYDF-UHFFFAOYSA-N cyclohexanone Chemical compound O=C1CCCCC1 JHIVVAPYMSGYDF-UHFFFAOYSA-N 0.000 description 2
- 239000003822 epoxy resin Substances 0.000 description 2
- 238000001914 filtration Methods 0.000 description 2
- 238000010438 heat treatment Methods 0.000 description 2
- 239000012948 isocyanate Substances 0.000 description 2
- 238000004898 kneading Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- PHQOGHDTIVQXHL-UHFFFAOYSA-N n'-(3-trimethoxysilylpropyl)ethane-1,2-diamine Chemical compound CO[Si](OC)(OC)CCCNCCN PHQOGHDTIVQXHL-UHFFFAOYSA-N 0.000 description 2
- 150000003014 phosphoric acid esters Chemical class 0.000 description 2
- 239000002985 plastic film Substances 0.000 description 2
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 description 2
- 229920000647 polyepoxide Polymers 0.000 description 2
- 238000003756 stirring Methods 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- WYTZZXDRDKSJID-UHFFFAOYSA-N (3-aminopropyl)triethoxysilane Chemical compound CCO[Si](OCC)(OCC)CCCN WYTZZXDRDKSJID-UHFFFAOYSA-N 0.000 description 1
- JLPULHDHAOZNQI-ZTIMHPMXSA-N 1-hexadecanoyl-2-(9Z,12Z-octadecadienoyl)-sn-glycero-3-phosphocholine Chemical compound CCCCCCCCCCCCCCCC(=O)OC[C@H](COP([O-])(=O)OCC[N+](C)(C)C)OC(=O)CCCCCCC\C=C/C\C=C/CCCCC JLPULHDHAOZNQI-ZTIMHPMXSA-N 0.000 description 1
- IIZPXYDJLKNOIY-JXPKJXOSSA-N 1-palmitoyl-2-arachidonoyl-sn-glycero-3-phosphocholine Chemical compound CCCCCCCCCCCCCCCC(=O)OC[C@H](COP([O-])(=O)OCC[N+](C)(C)C)OC(=O)CCC\C=C/C\C=C/C\C=C/C\C=C/CCCCC IIZPXYDJLKNOIY-JXPKJXOSSA-N 0.000 description 1
- OEPOKWHJYJXUGD-UHFFFAOYSA-N 2-(3-phenylmethoxyphenyl)-1,3-thiazole-4-carbaldehyde Chemical compound O=CC1=CSC(C=2C=C(OCC=3C=CC=CC=3)C=CC=2)=N1 OEPOKWHJYJXUGD-UHFFFAOYSA-N 0.000 description 1
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 1
- SJECZPVISLOESU-UHFFFAOYSA-N 3-trimethoxysilylpropan-1-amine Chemical compound CO[Si](OC)(OC)CCCN SJECZPVISLOESU-UHFFFAOYSA-N 0.000 description 1
- 239000001856 Ethyl cellulose Substances 0.000 description 1
- ZZSNKZQZMQGXPY-UHFFFAOYSA-N Ethyl cellulose Chemical compound CCOCC1OC(OC)C(OCC)C(OCC)C1OC1C(O)C(O)C(OC)C(CO)O1 ZZSNKZQZMQGXPY-UHFFFAOYSA-N 0.000 description 1
- 239000005057 Hexamethylene diisocyanate Substances 0.000 description 1
- 229910001030 Iron–nickel alloy Inorganic materials 0.000 description 1
- 229920000459 Nitrile rubber Polymers 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- BLRPTPMANUNPDV-UHFFFAOYSA-N Silane Chemical compound [SiH4] BLRPTPMANUNPDV-UHFFFAOYSA-N 0.000 description 1
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 230000002411 adverse Effects 0.000 description 1
- 238000005054 agglomeration Methods 0.000 description 1
- 125000003545 alkoxy group Chemical group 0.000 description 1
- 229920000180 alkyd Polymers 0.000 description 1
- 150000003973 alkyl amines Chemical class 0.000 description 1
- 125000000217 alkyl group Chemical group 0.000 description 1
- 125000002947 alkylene group Chemical group 0.000 description 1
- 229910045601 alloy Inorganic materials 0.000 description 1
- 239000000956 alloy Substances 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 150000001412 amines Chemical class 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 239000012298 atmosphere Substances 0.000 description 1
- 238000003490 calendering Methods 0.000 description 1
- 239000003054 catalyst 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
- 230000000052 comparative effect Effects 0.000 description 1
- 238000007796 conventional method Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 238000004132 cross linking Methods 0.000 description 1
- 230000006866 deterioration Effects 0.000 description 1
- 230000007613 environmental effect Effects 0.000 description 1
- 125000003700 epoxy group Chemical group 0.000 description 1
- 235000019325 ethyl cellulose Nutrition 0.000 description 1
- 229920001249 ethyl cellulose Polymers 0.000 description 1
- 238000009472 formulation Methods 0.000 description 1
- 125000000524 functional group Chemical group 0.000 description 1
- 239000003292 glue Substances 0.000 description 1
- LNEPOXFFQSENCJ-UHFFFAOYSA-N haloperidol Chemical compound C1CC(O)(C=2C=CC(Cl)=CC=2)CCN1CCCC(=O)C1=CC=C(F)C=C1 LNEPOXFFQSENCJ-UHFFFAOYSA-N 0.000 description 1
- RRAMGCGOFNQTLD-UHFFFAOYSA-N hexamethylene diisocyanate Chemical compound O=C=NCCCCCCN=C=O RRAMGCGOFNQTLD-UHFFFAOYSA-N 0.000 description 1
- 125000002887 hydroxy group Chemical group [H]O* 0.000 description 1
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 description 1
- 238000011221 initial treatment Methods 0.000 description 1
- 230000003993 interaction Effects 0.000 description 1
- 239000000787 lecithin Substances 0.000 description 1
- 235000010445 lecithin Nutrition 0.000 description 1
- 229940067606 lecithin Drugs 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 229910052758 niobium Inorganic materials 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- AJCDFVKYMIUXCR-UHFFFAOYSA-N oxobarium;oxo(oxoferriooxy)iron Chemical compound [Ba]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O.O=[Fe]O[Fe]=O AJCDFVKYMIUXCR-UHFFFAOYSA-N 0.000 description 1
- 229920001568 phenolic resin Polymers 0.000 description 1
- 239000005011 phenolic resin Substances 0.000 description 1
- 239000010452 phosphate Substances 0.000 description 1
- 229920006255 plastic film Polymers 0.000 description 1
- 239000004014 plasticizer Substances 0.000 description 1
- 229920002239 polyacrylonitrile Polymers 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920001748 polybutylene Polymers 0.000 description 1
- 229920006267 polyester film Polymers 0.000 description 1
- 229920001296 polysiloxane Polymers 0.000 description 1
- 229920002635 polyurethane Polymers 0.000 description 1
- 239000004814 polyurethane Substances 0.000 description 1
- 229920002689 polyvinyl acetate Polymers 0.000 description 1
- 239000011118 polyvinyl acetate Substances 0.000 description 1
- 229920000915 polyvinyl chloride Polymers 0.000 description 1
- 239000004800 polyvinyl chloride Substances 0.000 description 1
- 238000010992 reflux Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 229910000077 silane Inorganic materials 0.000 description 1
- 229910052710 silicon Inorganic materials 0.000 description 1
- 239000010703 silicon Substances 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 239000000243 solution Substances 0.000 description 1
- 229940083466 soybean lecithin Drugs 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 230000006641 stabilisation Effects 0.000 description 1
- 238000011105 stabilization Methods 0.000 description 1
- 230000000087 stabilizing effect Effects 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- 239000002345 surface coating layer Substances 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
- DVKJHBMWWAPEIU-UHFFFAOYSA-N toluene 2,4-diisocyanate Chemical compound CC1=CC=C(N=C=O)C=C1N=C=O DVKJHBMWWAPEIU-UHFFFAOYSA-N 0.000 description 1
- 230000001988 toxicity Effects 0.000 description 1
- 231100000419 toxicity Toxicity 0.000 description 1
- 229910052720 vanadium Inorganic materials 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 229910052725 zinc Inorganic materials 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
- G11B5/62—Record carriers characterised by the selection of the material
- G11B5/68—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent
- G11B5/70—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer
- G11B5/702—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the bonding agent
- G11B5/7023—Record carriers characterised by the selection of the material comprising one or more layers of magnetisable material homogeneously mixed with a bonding agent on a base layer characterised by the bonding agent containing polyesters, polyethers, silicones, polyvinyl resins, polyacrylresins or epoxy resins
Description
本発明は改良された磁気記録体の製造法に関す
る。更に詳しくは、磁気記録再生用磁気テープ、
磁気デイスクなどの磁気記録体の製造において強
磁性微粉末の分散性を改良して磁性塗料の塗料化
を容易にし、塗工性、加工性を改善して磁気特性
を向上させた磁気記録体の製造法に関する。
磁気テープ、磁気デイスクなどの磁気記録体中
の磁性粉は高度の分散が要求される。磁気記録体
となる磁性膜は磁性塗料をプラスチツクのフイル
ムやシートの基板上に均一に塗布して乾燥後、磁
性層を鏡面仕上して形成されるが、塗料中で磁性
粉を十分に分散解膠して凝集粒子を除いておかな
いと均一で平滑な磁性層を作ることができない。
このような磁性粉の凝集粒子による磁性層の不均
一は磁気テープの電磁変換特性及び磁気特性に重
大な悪影響を及ぼす。即ち、出力の低下、ノイズ
の増大、ドロツプアウトなどの原因となる。又塗
料中の磁性粉の分散が不良のときは塗膜物性が不
良で耐久性が劣り、更にオーデイオテープ、
VTRテープで要求されるような磁性粉の配向が
不十分となり磁気特性が不良となる。
このように磁性塗料中の磁性粉の分散は磁気記
録体の性能を向上させる上に非常に重要である。
従つて磁性粉の分散性の向上については種種の観
点から研究されており、磁性塗料配合に適当な界
面活性剤を加えて分散性を改良することが提案さ
れている。このような界面活性剤としてはアルキ
ルイミダゾリン化合物を用いるもの（特開昭54−
32304）、アルキルポリオキシエチレンリン酸エス
テルをアルキルアミンで中和して用いるもの（特
開昭53−78810）、長鎖アルキルリン酸エステルを
用いるもの（特開昭54−147507、特願昭53−
49629）などのようにアミンとその誘導体、リン
酸エステル、ポリオキシエチレンリン酸エステル
類などを利用することが多い。また、磁性粉を表
面処理してから塗料化すると分散性が改良される
とする提案があり、アルキルポリオキシエチレン
リン酸エステルを用いるもの（特開昭54−94308、
同56−49769）、メタル粉をチタンカツプリング剤
で処理して分散安定性と同時に磁性塗膜の経時劣
化を防ぐもの（特開昭56−88471）、バインダーと
反応性の官能基をもつシランカツプリング剤を用
いるもの（特開昭54−7310）、アミノフアンクシ
ヨナルシランカツプリング剤とイソシアネート系
化合物、エポキシ系化合物との反応生成物によつ
て被覆するもの（特開昭56−143533）などがあ
る。
磁性粉の分散性向上に有利なバインダーを選択
して用いる方法も多く提案されている。また塗料
化に当つて第１段階として分散に有利なバインダ
ーのみ、またはこれに適当な界面活性剤を加えて
混練し、次いで分散には不利であるが磁性塗膜と
しての特性の優れたバインダーを添加して短時間
混練して分散性の良好な塗料を製造する方法も提
案されている。多くの場合、磁性粉の分散に有利
なバインダーとされているものは硝化綿、塩化ビ
ニル酢酸ビニルコポリマー、ポリビニルブチラー
ル、ポリビニルホルマールなどであり、分散に不
利なバインダーとされているものはポリウレタン
樹脂、フエノール樹脂、エポキシ樹脂である。し
かしながら、ここでいう分散に有利なバインダー
であつても磁性粉の分散性は必ずしも満足できる
ものではない。これらのバインダーは磁性粉を基
板上に固着させる能力やテープとしての諸物性に
優れたものでなくてはならず、分散性の良否のみ
の観点から選ぶことはできない。
このように磁性塗料の分散性改良に対する多く
の研究がなされてきたにもかかわらず、今だに満
足すべき改良の段階には到達しておらず、塗料構
成成分の改質、塗料の混練機と混練時間、塗料構
成成分の添加順序などの改善により塗料の貯蔵安
定性、塗工特性、塗膜特性など多くの点で改良す
ることが要求されている。
一方、磁気テープ、磁気デイスクなどの磁気記
録体に使われる磁性粉は、記録の高密度化、低ノ
イズ化、高周波領域における音響特性の向上のた
め粒径はより小さく、抗磁力はより大きなものを
使うことが必要となつてきている。磁性粉のγ−
酸化鉄、コバルト被着γ−酸化鉄、メタル粉など
はいずれも0.3μ或いはそれ以下の大きさのものを
用いることが必要となつているが、磁性粉の粒径
が小さくなると表面積が大きくなり、このような
表面エネルギーの高い粒子の分散は困難となる。
また、磁性粉は磁気モーメントによる粒子間相互
作用（吸引力）により普通の粉末に比べ分散が困
難である。磁性粉の分散性が不十分なため磁性塗
膜の物性を犠牲にして現在開発されている分散に
有利なバインダーのみを選ぶとテープ等の耐久性
に悪い影響を与えるため実用的ではない。
又、従来、磁性塗料の分散性を向上させるため
に提案されている界面活性剤の分散能力は、有機
溶媒にこれを溶解させ磁性粉を加えて混練した時
は非常に優れているが、この分散系にポリウレタ
ン樹脂のような塗膜特性を良好にするために必須
なバインダーを加えて塗料系とすると分散性が劣
化して凝集するという欠点がある。界面活性剤を
吸着して溶剤中に分散している磁性粉は溶剤中に
バインダーが存在すると多かれ少なかれその分散
性が影響を受ける。良好な性質をもつ磁性塗膜の
可撓性、耐摩耗性などの必要な物性のために必須
なバインダーであるポリウレタン樹脂、塩化ビニ
ル酢酸ビニル共重合樹脂が共存するときは分散性
は特に悪化する。これは磁性粉表面に界面活性剤
が吸着して磁性粉−溶剤界面の界面エネルギーを
低下させて分散安定化しているものが、バインダ
ーが共在すると界面エネルギーが再び増大して分
散性が悪化するか又は界面エネルギーが低いまま
でバインダーの粒子間架橋などによる凝集作用が
起こるかのいずれかのことが考えられる。
本発明者らはバインダーの凝集作用の原因を知
るべくバインダーの共存下における磁性粉表面へ
の界面活性剤の吸着量を調べたところ、分散性に
悪い影響を与えるバインダーはその吸着量を著し
く低下させ或る種の界面活性剤−バインダーの組
合せにおいては驚くべきことに吸着量を零にして
しまうことが判明した。本発明者等はこの事実に
基づきいかなるバインダーの共存においても磁性
粉表面から脱着せずに更に塗料系中で強磁性粉末
粒子が最もよく分散するために必要な表面コート
層の構造につき鋭意研究の結果、本発明を完成す
るに至つたものである。
即ち、本発明は強磁性微粉末をアミノ基含有シ
ランカツプリング剤で処理し、次いで分子量500
〜8000のウレタン系有機オリゴマー化合物又はエ
ポキシ系有機オリゴマー化合物で処理した後、有
機バインダーとともに基板上に塗布することを特
徴とする磁気記録体の製造法を提供するものであ
る。
本発明において用いられるアミノ基含有シラン
カツプリング剤としては、例えば
H2NC2H4NHC3H6Si（OCH3）3，
H2NC2H4NHC3H6Si（CH3）（OCH3）2，
H2NC3H6Si（OC2H5）3，H2NCONHC3H6Si
（OC2H5）3，
The present invention relates to an improved method of manufacturing magnetic recording media. More specifically, magnetic tape for magnetic recording and reproduction;
In the production of magnetic recording media such as magnetic disks, the dispersibility of ferromagnetic fine powder has been improved to make it easier to turn magnetic paints into paints, and the magnetic properties of magnetic recording media have been improved by improving coatability and processability. Regarding manufacturing methods. Magnetic powder in magnetic recording media such as magnetic tapes and magnetic disks requires a high degree of dispersion. The magnetic film that serves as the magnetic recording medium is formed by uniformly applying magnetic paint onto a plastic film or sheet substrate, drying it, and then giving the magnetic layer a mirror finish. However, the magnetic powder must be sufficiently dispersed and dissolved in the paint. Unless agglomerated particles are removed using glue, a uniform and smooth magnetic layer cannot be created.
Non-uniformity of the magnetic layer due to such agglomerated particles of magnetic powder has a serious adverse effect on the electromagnetic conversion characteristics and magnetic properties of the magnetic tape. That is, it causes a decrease in output, an increase in noise, dropouts, etc. In addition, if the magnetic powder in the paint is poorly dispersed, the physical properties of the paint film will be poor, resulting in poor durability.
The orientation of the magnetic powder required for VTR tapes is insufficient, resulting in poor magnetic properties. As described above, dispersion of magnetic powder in magnetic paint is very important for improving the performance of magnetic recording media.
Therefore, the improvement of the dispersibility of magnetic powder has been studied from various viewpoints, and it has been proposed to improve the dispersibility by adding a suitable surfactant to the magnetic paint formulation. As such a surfactant, an alkyl imidazoline compound is used (Japanese Patent Application Laid-Open No. 1989-1999).
32304), those using an alkyl polyoxyethylene phosphate ester neutralized with an alkylamine (Japanese Patent Application Laid-Open No. 53-78810), those using a long-chain alkyl phosphate ester (Japanese Patent Application Laid-Open No. 1983-147507, Patent Application No. 1983) −
49629), amines and their derivatives, phosphate esters, and polyoxyethylene phosphate esters are often used. In addition, there has been a proposal that dispersibility is improved by surface-treating magnetic powder and then turning it into a paint.
56-49769), treatment of metal powder with a titanium coupling agent to improve dispersion stability and prevent the deterioration of magnetic coatings over time (Japanese Patent Application Laid-open No. 56-88471), silane with a functional group reactive with the binder. Those using a coupling agent (Japanese Patent Application Laid-open No. 54-7310), those coated with a reaction product of an aminofunctional silane coupling agent, an isocyanate compound, or an epoxy compound (Japanese Patent Application Laid-open No. 56-143533) and so on. Many methods have been proposed for selecting and using binders that are advantageous in improving the dispersibility of magnetic powder. In addition, the first step in making a coating is to knead only a binder that is advantageous for dispersion, or add an appropriate surfactant to it, and then add a binder that is disadvantageous for dispersion but has excellent properties as a magnetic coating. A method of producing a paint with good dispersibility by adding and kneading for a short time has also been proposed. In many cases, binders considered to be advantageous for dispersing magnetic powder include nitrified cotton, vinyl chloride vinyl acetate copolymer, polyvinyl butyral, and polyvinyl formal, while binders considered disadvantageous for dispersion include polyurethane resin, These are phenolic resin and epoxy resin. However, even if the binder is advantageous for dispersion, the dispersibility of the magnetic powder is not necessarily satisfactory. These binders must be excellent in the ability to fix the magnetic powder on the substrate and in various physical properties as a tape, and cannot be selected based solely on the quality of dispersibility. Despite much research into improving the dispersibility of magnetic paints, we have not yet reached the stage of satisfactory improvement. There is a need to improve the storage stability, coating properties, and coating film properties of paints by improving the kneading time, the order of addition of paint constituents, etc. On the other hand, magnetic powder used in magnetic recording media such as magnetic tapes and magnetic disks has smaller particle diameters and larger coercive force in order to achieve higher recording density, lower noise, and improve acoustic properties in high frequency ranges. It has become necessary to use γ− of magnetic powder
It is necessary to use iron oxide, cobalt-coated γ-iron oxide, metal powder, etc. all with a size of 0.3μ or less, but as the particle size of magnetic powder decreases, the surface area increases. , it becomes difficult to disperse particles with such high surface energy.
Furthermore, magnetic powder is more difficult to disperse than ordinary powder due to interparticle interaction (attractive force) caused by magnetic moment. Since the dispersibility of the magnetic powder is insufficient, it is not practical to select only the currently developed binder that is advantageous for dispersion at the expense of the physical properties of the magnetic coating because it will have a negative effect on the durability of the tape, etc. In addition, the dispersion ability of surfactants, which have been proposed to improve the dispersibility of magnetic paints, is excellent when dissolved in an organic solvent and mixed with magnetic powder. If a paint system is prepared by adding a binder such as a polyurethane resin, which is essential for improving coating properties, to the dispersion system, there is a drawback that the dispersibility deteriorates and agglomeration occurs. The dispersibility of magnetic powder that adsorbs a surfactant and is dispersed in a solvent is more or less affected by the presence of a binder in the solvent. Dispersibility is particularly poor when polyurethane resins and vinyl chloride-vinyl acetate copolymer resins, which are essential binders for magnetic coatings with good properties such as flexibility and abrasion resistance, coexist. . This is because the surfactant is adsorbed to the surface of the magnetic powder, lowering the interfacial energy at the magnetic powder-solvent interface and stabilizing the dispersion, but when a binder coexists, the interfacial energy increases again and the dispersibility worsens. It is conceivable that either the interfacial energy remains low and aggregation occurs due to interparticle crosslinking of the binder. The present inventors investigated the amount of surfactant adsorbed to the magnetic powder surface in the presence of binder in order to understand the cause of binder aggregation, and found that binder, which has a negative effect on dispersibility, significantly reduced the adsorption amount. It has surprisingly been found that certain surfactant-binder combinations reduce adsorption to zero. Based on this fact, the present inventors have conducted extensive research into the structure of the surface coating layer necessary for the best dispersion of ferromagnetic powder particles in the paint system without being desorbed from the magnetic powder surface in the presence of any binder. As a result, the present invention has been completed. That is, in the present invention, ferromagnetic fine powder is treated with an amino group-containing silane coupling agent, and then the molecular weight is 500.
The present invention provides a method for producing a magnetic recording material, which comprises treating the substrate with a urethane-based organic oligomer compound or an epoxy-based organic oligomer compound of 8,000 and then coating the substrate together with an organic binder. Examples of the amino group-containing silane coupling agent used in the present invention include H 2 NC 2 H 4 NHC 3 H 6 Si(OCH 3 ) 3 ,
H 2 NC 2 H 4 NHC 3 H 6 Si(CH 3 )(OCH 3 ) 2 ,
H 2 NC 3 H 6 Si (OC 2 H 5 ) 3 , H 2 NCONHC 3 H 6 Si
( OC2H5 ) 3 ,
【式】等を挙
げることができる。
これらのアミノ基含有シランカツプリング剤の
強磁性粉末表面への処理は水又は有機溶剤にアミ
ノ基含有シランカツプリング剤を溶解した後、強
磁性粉末を投入し撹拌混合後別して加熱乾燥す
ることによつて行うことができる。
又、他の処理方法としてはアミノ基含有シラン
カツプリング剤溶液を流動床装置又はヘンシエル
ミキサーなどの粉体撹拌機中で強磁性粉末に直接
スプレーコーテイングした後加熱乾燥することに
よつてもできる。このような処理によりアミノ基
含有シランカツプリング剤のアルコキシ基は強磁
性微粉末表面で加水分解されアミノ基含有シラン
カツプリング剤は固定される。
アミノ基含有シランカツプリング剤の使用量
は、強磁性粉末に対し重量比で0.1〜10％、好ま
しくは0.2〜２％である。
上記の方法で処理された強磁性粉末は次にアミ
ノ基含有シランカツプリング剤のアミノ基と反応
するウレタン系又はエポキシ系有機オリゴマー化
合物で処理される。
ウレタン系有機オリゴマーの例としては、例え
ば、分子の末端がヒドロキシル基であるアジピン
酸／１，４−ブタンジオールポリエステル、アジ
ピン酸／ビスフエノールＡのアルキレンオキサイ
ド付加物ポリエステル、ポリブチレングリコール
等と各種ジイソシアナート化合物との反応物で少
なくとも末端の一方がイソシアナート基を有する
ものである。
エポキシ系有機オリゴマーの例としてはビスフ
エノールＡ／エピクロルヒドリン縮合物、ビスフ
エノールＡのアルキレンオキサイド付加物／エピ
クロルヒドリン縮合物がある。
本発明になる有機オリゴマーの分子量は500〜
8000、好ましくは1000〜4000の範囲のものであ
り、分子量がこれより小さくても又は大きくても
磁性粉末の分散性が不良となる。
強磁性粉末表面のアミノ基含有シランカツプリ
ング剤残基と反応するこれらオリゴマーの粉体に
対する処理量は理想的にはシランカツプリング剤
残基とモル等量の反応基をもつオリゴマー量を使
用するのがよいが、実際には必ずしも化学量論的
な反応が起らないから理論量より多く使用する必
要がある。一般には強磁性粉末に対して１〜20重
量％、好ましくは２〜10重量％の量を使用する。
これらのオリゴマーとアミノ基含有シランカツ
プリング剤残基との反応は一般には有機溶媒中に
アミノ基含有シランカツプリング剤処理した強磁
性微粉末を懸濁させてから所定量の反応性オリゴ
マーを加え、必要に応じ触媒を加えて加熱して反
応を起させる。反応終了後は過剰の溶媒を別し
て除き、そのまま、又は乾燥して表面処理を完了
する。このようにして表面処理した強磁性微粉末
は塗料化に際して溶剤によくなじみ、分散安定化
のために最適な厚さの吸着層を有しているから磁
性塗料の分散安定性が大きく塗工し易く、磁場配
向により強磁性体粒子が配向し易く、磁性膜の均
一性が高く、従つてこの磁気記録体の電磁特性は
優れたものとなる。
本発明に用いる磁性粉末としては針状形の微細
なγ−Fe2O3，Fe3O4，CrO2のような金属酸化
物、又Co被着γ−Fe2O3，Coドープγ−Fe2O3の
ような加工処理を施したγ−Fe2O3，鉄メタル
粉、微小板状のバリウムフエライトおよびその
Fe原子の一部がTi，Co，Zn，Ｖ，Nb等の１種
または２種以上で置換された磁性粉、Co，Fe−
Co，Fe−Ni等の金属または合金の超微粉などが
挙げられる。これらのうち鉄メタル粉は特に化学
的安定性が悪いからこの改良のためニツケル、コ
バルト、チタン、ケイ素、アルミニウムなどを金
属原子、塩及び酸化物の形で少量加えたり表面処
理されることがあるがこれらを用いることもでき
る。鉄メタル粉は又その安定化のため弱い酸化性
雰囲気の中で表面に薄い酸化被膜を作らせること
があるが、このように処理されたメタル粉を用い
ることもできる。
これらの磁性粉末の大きさは長軸が1μから
0.15μ、短軸が0.15μから0.015μのものが好ましい。
長軸が1μより大きくなると分散は容易になるが
短波長の記録が不利になつたりノイズが大きくな
るため好ましくない。長軸が0.15μより小さくな
ると本発明になる磁気記録体としてもなお分散が
困難となる。
本発明に用いられる有機バインダーは有機溶剤
に可溶な樹脂バインダーであり、上記の磁性粉末
を基板上に及び磁性粉末同志を必要な強さで固着
して磁性層とするためにできるだけ少量でその役
割をはたすものであればよく、従来塗料中の磁性
粉末の分散性を悪化する懸念のあるものも通常の
塗料化方法で用いることができる。これらの樹脂
バインダーの例としてはポリウレタン、ポリエス
テル、ポリ塩化ビニル、塩化ビニル酢酸ビニル共
重合体、ポリアクリルニトリル、ニトリルゴム、
エポキシ樹脂、アルキツド樹脂、ポリアミド、ポ
リアクリル酸エステル、ポリメタクリル酸エステ
ル、ポリ酢酸ビニル、ポリビニルブチラール、塩
化ビニリデン、塩化ビニリデン共重合体、硝化
綿、エチルセルロースなどが挙げられるがこれら
は単独で用いてもよいが、通常２種類以上混合し
て用いられる。又、樹脂の硬さを調節するため可
塑剤や硬化剤を加えて使用することもできる。
本発明において、バインダーの配合量は磁性粉
末100重量部に対して15〜60重量部である。最も
大きな結合力を有するバインダーであつても15重
量部より少ないときは磁性塗膜の強度が弱くまた
基板と磁性塗膜の接着力が不足となる。又60重量
部より多いときは磁性塗膜中の磁性粉末濃度が小
さくなつて再生出力が低下して不利であるし、又
塗膜特性が低下することもある。
本発明に用いられる溶剤は使用するバインダー
に対して溶解力を有し且つ沸点が50℃から150℃
の間にあるものが望ましい。沸点が低すぎると塗
布後磁性粉の磁場配向する前に乾燥してしまいこ
の処理をすることができない。バインダーの種類
に対応して上記の観点から選択されるが毒性や環
境の問題を考慮して選ぶべきことはいうまでもな
い。
本発明の製造法を用いることにより、磁性塗料
製造において著しく分散性を向上させることがで
き、塗工性、加工性に優れ電磁特性の優れた磁気
記録体を製造することができる。
以下実施例をもつて本発明を詳述するが本発明
はこれらに限定されるものではない。
実施例 １
長軸平均粒径0.3μm、軸比１／10のγ−
Fe2O320重量部をＮ−β−（アミノエチル）−γ−
アミノプロピルトリメトキシシラン（東レシリコ
ーンSH6020）0.2％水溶液100重量部に投入して
ラボミキサーにより30分間撹拌混合した。水をろ
別して除いた後120℃で２時間乾燥してから粉砕
して１次処理を行なつた。
冷却還流管をつけたフラスコにシランカツプリ
ング剤処理したγ−Fe2O320ｇをメチルイソブチ
ルケトン（MIBK）100ｇ中に懸濁して表−１に
示す各種反応性オリゴマーを２ｇ加え撹拌しなが
ら１〜３時間加熱して２次処理を行なつた。冷却
後MIBKをろ別して除いた後、乾燥することなし
にそのまま塗料化試料とした。
このように表面処理して得たγ−Fe2O3を乾燥
物換算で30重量部、塩化ビニル酢酸ビニル樹脂
（ユニオンカーバイト社製VAGH）５重量部、メ
チルエチルケトン（MEK）31重量部、シクロヘ
キサノン31重量部をボールミルにとつて20時間混
練した後ポリウレタン樹脂（グツドリツチ社製エ
スタン5702）2.5重量部、レベリング剤（花王石
鹸、ホモゲノールＬ−100）0.2重量部、硬化剤
（住友バイエルン社製、デイスモジユールＮ−75）
0.75重量部を加えて更に４時間混練して磁性塗料
を作製した。
これらの塗料をポリエステルフイルム上に乾燥
磁性塗膜の厚さが3μmになるように塗布して磁場
配向を行なつた後熱風乾燥した。この磁性塗膜を
カレンダー処理して平滑化して磁気記録体を得
た。これについて塗膜特性、電磁特性を評価し
た。結果を表−１に示す。
表−１中の比較例「未処理γ−Fe2O3」は本実
施例に用いたγ−Fe2O3の表面処理を全く行なわ
ずに、又「SH−6020処理γ−Fe2O3」はシラン
カツプリング剤処理のみを行ない、反応性オリゴ
マーによる処理を行なわずに磁気記録体を製造し
たものである。又「レシチン添加」は未処理γ−
Fe2O3を用いて塗料化する際大豆レシチンを磁性
粉末に対して３重量パーセント添加して磁気記録
体を製造したものである。又、反応性オリゴマー
の分子量は通常の蒸気圧降下法によつて測定した
ものである。
表−１より明らかな如く本発明に係わる磁気記
録体が優れた特性を示すことが判る。[Formula] etc. can be mentioned. The treatment of these amino group-containing silane coupling agents on the surface of ferromagnetic powders involves dissolving the amino group-containing silane coupling agents in water or an organic solvent, adding the ferromagnetic powder, stirring and mixing, and then heating and drying separately. You can do it by leaning. Another treatment method is to directly spray coat the ferromagnetic powder with an amino group-containing silane coupling agent solution in a fluidized bed apparatus or a powder stirrer such as a Henschel mixer, and then heat and dry it. . By such treatment, the alkoxy group of the amino group-containing silane coupling agent is hydrolyzed on the surface of the ferromagnetic fine powder, and the amino group-containing silane coupling agent is fixed. The amount of the amino group-containing silane coupling agent used is 0.1 to 10% by weight, preferably 0.2 to 2%, based on the weight of the ferromagnetic powder. The ferromagnetic powder treated in the above manner is then treated with a urethane-based or epoxy-based organic oligomer compound that reacts with the amino groups of the amino group-containing silane coupling agent. Examples of urethane-based organic oligomers include adipic acid/1,4-butanediol polyester with a hydroxyl group at the end of the molecule, alkylene oxide adduct polyester of adipic acid/bisphenol A, polybutylene glycol, etc. It is a reaction product with an isocyanate compound and has at least one end having an isocyanate group. Examples of epoxy organic oligomers include bisphenol A/epichlorohydrin condensate and bisphenol A alkylene oxide adduct/epichlorohydrin condensate. The molecular weight of the organic oligomer of the present invention is 500~
8,000, preferably in the range of 1,000 to 4,000, and if the molecular weight is smaller or larger than this, the dispersibility of the magnetic powder will be poor. The amount of these oligomers that react with the amino group-containing silane coupling agent residue on the surface of the ferromagnetic powder to be treated with the powder should ideally be an amount of oligomer having a reactive group in a molar equivalent amount to the silane coupling agent residue. However, in reality, stoichiometric reactions do not necessarily occur, so it is necessary to use more than the theoretical amount. Generally, amounts of 1 to 20%, preferably 2 to 10% by weight, based on the ferromagnetic powder, are used. The reaction between these oligomers and residues of the amino group-containing silane coupling agent is generally carried out by suspending fine ferromagnetic powder treated with the amino group-containing silane coupling agent in an organic solvent, and then adding a predetermined amount of the reactive oligomer. , if necessary, add a catalyst and heat to cause a reaction. After the reaction is completed, excess solvent is removed separately and the surface treatment is completed either as is or by drying. The ferromagnetic fine powder that has been surface-treated in this way is well compatible with solvents when it is made into a paint, and has an adsorption layer with an optimal thickness for dispersion stabilization, so the dispersion stability of the magnetic paint is greatly improved. The ferromagnetic particles are easily oriented by magnetic field orientation, the magnetic film has high uniformity, and the electromagnetic properties of this magnetic recording medium are excellent. The magnetic powder used in the present invention includes fine needle-shaped metal oxides such as γ-Fe 2 O 3 , Fe 3 O 4 , CrO 2 , Co-coated γ-Fe 2 O 3 , Co-doped γ- γ-Fe 2 O 3 processed like Fe 2 O 3 , iron metal powder, microplate-like barium ferrite and its
Magnetic powder in which a part of Fe atoms are substituted with one or more of Ti, Co, Zn, V, Nb, etc., Co, Fe-
Examples include ultrafine powder of metals or alloys such as Co, Fe-Ni, etc. Among these, iron metal powder has particularly poor chemical stability, so to improve this, small amounts of nickel, cobalt, titanium, silicon, aluminum, etc. are added in the form of metal atoms, salts, and oxides, or the surface is treated. However, these can also be used. In order to stabilize iron metal powder, a thin oxide film may be formed on the surface in a weakly oxidizing atmosphere, and metal powder treated in this way can also be used. The size of these magnetic powders is from 1μ in the long axis.
Preferably, the diameter is 0.15μ, and the short axis is 0.15μ to 0.015μ.
If the long axis is larger than 1μ, dispersion becomes easier, but it is not preferable because recording of short wavelengths becomes disadvantageous and noise becomes large. When the long axis is smaller than 0.15μ, it becomes difficult to disperse the magnetic recording material according to the present invention. The organic binder used in the present invention is a resin binder that is soluble in organic solvents, and is used in as small a quantity as possible to form a magnetic layer by fixing the above-mentioned magnetic powder onto a substrate with the necessary strength. Any material may be used as long as it fulfills its role, and even materials that are likely to deteriorate the dispersibility of magnetic powder in conventional paints can be used in normal paint-forming methods. Examples of these resin binders include polyurethane, polyester, polyvinyl chloride, vinyl chloride vinyl acetate copolymer, polyacrylonitrile, nitrile rubber,
Epoxy resins, alkyd resins, polyamides, polyacrylic esters, polymethacrylic esters, polyvinyl acetate, polyvinyl butyral, vinylidene chloride, vinylidene chloride copolymers, nitrified cotton, ethyl cellulose, etc. may be used alone. However, two or more types are usually used in combination. Further, in order to adjust the hardness of the resin, a plasticizer or a hardening agent may be added to the resin. In the present invention, the blending amount of the binder is 15 to 60 parts by weight per 100 parts by weight of the magnetic powder. Even if the binder has the highest binding strength, if it is less than 15 parts by weight, the strength of the magnetic coating will be weak and the adhesive strength between the substrate and the magnetic coating will be insufficient. If the amount is more than 60 parts by weight, the concentration of the magnetic powder in the magnetic coating film becomes small, which is disadvantageous because the reproduction output decreases, and the properties of the coating film may also deteriorate. The solvent used in the present invention has a dissolving power for the binder used and has a boiling point of 50°C to 150°C.
Something in between is desirable. If the boiling point is too low, the coating will dry before the magnetic powder is oriented in the magnetic field after coating, making this treatment impossible. The binder is selected from the above viewpoints depending on the type of binder, but it goes without saying that it should be selected in consideration of toxicity and environmental issues. By using the production method of the present invention, it is possible to significantly improve the dispersibility in the production of magnetic paints, and it is possible to produce magnetic recording bodies that are excellent in coatability, workability, and electromagnetic properties. The present invention will be described in detail below with reference to Examples, but the present invention is not limited thereto. Example 1 γ- with major axis average particle diameter 0.3 μm and axial ratio 1/10
20 parts by weight of Fe 2 O 3 was added to N-β-(aminoethyl)-γ-
The mixture was added to 100 parts by weight of a 0.2% aqueous solution of aminopropyltrimethoxysilane (Toray Silicone SH6020) and stirred and mixed for 30 minutes using a lab mixer. After removing water by filtration, it was dried at 120°C for 2 hours and then ground to perform the primary treatment. In a flask equipped with a cooling reflux tube, 20 g of γ-Fe 2 O 3 treated with a silane coupling agent was suspended in 100 g of methyl isobutyl ketone (MIBK), and 2 g of various reactive oligomers shown in Table 1 were added to the suspension while stirring. Secondary treatment was performed by heating for ~3 hours. After cooling, MIBK was removed by filtration and used as a paint sample without drying. 30 parts by weight of γ-Fe 2 O 3 obtained by surface treatment in this way, 5 parts by weight of vinyl chloride vinyl acetate resin (VAGH manufactured by Union Carbide), 31 parts by weight of methyl ethyl ketone (MEK), cyclohexanone. 31 parts by weight were placed in a ball mill and kneaded for 20 hours, followed by 2.5 parts by weight of polyurethane resin (Estan 5702, manufactured by Gutsudoritsu), 0.2 parts by weight of leveling agent (Kao Soap, Homogenol L-100), hardening agent (Dismodyur, manufactured by Sumitomo Bayern). N-75)
0.75 parts by weight was added and kneaded for an additional 4 hours to prepare a magnetic paint. These paints were applied onto a polyester film so that the dried magnetic film had a thickness of 3 μm, and after magnetic field orientation was carried out, it was dried with hot air. This magnetic coating film was smoothed by calendering to obtain a magnetic recording medium. The coating film properties and electromagnetic properties were evaluated. The results are shown in Table-1. The comparative example "Untreated γ-Fe 2 O 3 " in Table 1 is the one without any surface treatment of γ-Fe 2 O 3 used in this example, and the "SH-6020 treated γ-Fe 2 O 3". No. 3 '' is a magnetic recording material manufactured by performing only the silane coupling agent treatment and without the reactive oligomer treatment. In addition, "lecithin addition" is untreated γ-
A magnetic recording medium was produced by adding soybean lecithin to magnetic powder in an amount of 3% by weight when forming a coating using Fe 2 O 3 . Further, the molecular weight of the reactive oligomer was measured by a conventional vapor pressure drop method. As is clear from Table 1, it can be seen that the magnetic recording material according to the present invention exhibits excellent characteristics.
【表】
＊ トルエンジイソシアナート ＊＊
ヘキサメチレンジイソシアナート
実施例 ２
実施例１において使用したγ−Fe2O3の代りに
長軸平均粒径0.35μm、軸比１／８のCo被着γ−
Fe2O3を使用し、又、シランカツプリング剤SH
−6020の代りにγ−アミノプロピルトリエトキシ
シラン（信越化学製KBE903）を使用する以外は
実施例１において述べた方法によりシランカツプ
リング剤処理を行なつた。
このようにして得たCo被着γ−Fe2O3に対して
実施例１において述べた方法により、常法により
合成したエポキシ系反応性オリゴマーで処理した
後同様の方法により磁気記録体を製造して塗膜特
性、磁気特性を評価した。
結果を表−２に示した。これより明らかな如く
本発明になる磁気記録体が優れた特性を有するこ
とがわかる。[Table] * Toluene diisocyanate **
Hexamethylene diisocyanate Example 2 Instead of the γ-Fe 2 O 3 used in Example 1, Co-coated γ- with a major axis average particle diameter of 0.35 μm and an axial ratio of 1/8 was used.
Using Fe 2 O 3 and also silane coupling agent SH
The silane coupling agent treatment was carried out by the method described in Example 1, except that γ-aminopropyltriethoxysilane (KBE903, manufactured by Shin-Etsu Chemical Co., Ltd.) was used in place of -6020. The thus obtained Co-coated γ-Fe 2 O 3 was treated with an epoxy-based reactive oligomer synthesized by a conventional method using the method described in Example 1, and then a magnetic recording material was manufactured using the same method. The coating film properties and magnetic properties were evaluated. The results are shown in Table-2. As is clear from this, it can be seen that the magnetic recording medium according to the present invention has excellent characteristics.
【表】
＊ 末端エポキシ基
[Table] *Terminal epoxy group
Claims (1)
ング剤で処理し、次いで分子量500〜8000の少な
くとも末端の一方がイソシアナート基を有するウ
レタン系有機オリゴマー化合物又はエポキシ系有
機オリゴマー化合物で処理した後、有機バインダ
ーとともに基板上に塗布することを特徴とする磁
気記録体の製造法。1 Ferromagnetic fine powder is treated with an amino group-containing silane coupling agent, and then treated with a urethane-based organic oligomer compound or an epoxy-based organic oligomer compound having a molecular weight of 500 to 8000 and at least one end having an isocyanate group. A method for producing a magnetic recording material, characterized by coating it on a substrate together with a binder.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57087752A JPS58205929A (en) | 1982-05-24 | 1982-05-24 | Manufacture of magnetic recording material |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP57087752A JPS58205929A (en) | 1982-05-24 | 1982-05-24 | Manufacture of magnetic recording material |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58205929A JPS58205929A (en) | 1983-12-01 |
| JPH0222447B2 true JPH0222447B2 (en) | 1990-05-18 |
Family
ID=13923666
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP57087752A Granted JPS58205929A (en) | 1982-05-24 | 1982-05-24 | Manufacture of magnetic recording material |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58205929A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US5277984A (en) * | 1990-02-02 | 1994-01-11 | Nippon Zeon Co., Ltd. | Magnetic recording medium comprising ferromagnetic powder, a silane compound, and a binder comprising an epoxy group and specified functional group |
| US5320914A (en) * | 1991-06-26 | 1994-06-14 | Nippon Zeon Co., Ltd. | Magnetic recording medium comprising a styrene copolymer or an acrylic copolymer |
| US5250085A (en) * | 1993-01-15 | 1993-10-05 | Minnesota Mining And Manufacturing Company | Flexible bonded abrasive articles, methods of production and use |
| JP2004276232A (en) * | 2003-02-24 | 2004-10-07 | Mitsubishi Electric Corp | Carbon nanotube dispersion liquid and method of manufacturing the same |
-
1982
- 1982-05-24 JP JP57087752A patent/JPS58205929A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58205929A (en) | 1983-12-01 |
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