JPS6358620A - Magnetic recording medium - Google Patents
Magnetic recording mediumInfo
- Publication number
- JPS6358620A JPS6358620A JP61201754A JP20175486A JPS6358620A JP S6358620 A JPS6358620 A JP S6358620A JP 61201754 A JP61201754 A JP 61201754A JP 20175486 A JP20175486 A JP 20175486A JP S6358620 A JPS6358620 A JP S6358620A
- Authority
- JP
- Japan
- Prior art keywords
- recording medium
- coercive force
- magnetic recording
- magnetic
- months
- 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.)
- Granted
Links
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- 230000005415 magnetization Effects 0.000 claims abstract description 6
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- 235000014113 dietary fatty acids Nutrition 0.000 description 5
- 239000000194 fatty acid Substances 0.000 description 5
- 229930195729 fatty acid Natural products 0.000 description 5
- 239000006247 magnetic powder Substances 0.000 description 5
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- 150000004665 fatty acids Chemical class 0.000 description 3
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- IQPQWNKOIGAROB-UHFFFAOYSA-N isocyanate group Chemical group [N-]=C=O IQPQWNKOIGAROB-UHFFFAOYSA-N 0.000 description 3
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- QAOWNCQODCNURD-UHFFFAOYSA-N sulfuric acid Chemical group OS(O)(=O)=O QAOWNCQODCNURD-UHFFFAOYSA-N 0.000 description 3
- 239000004094 surface-active agent Substances 0.000 description 3
- 229920005992 thermoplastic resin Polymers 0.000 description 3
- 229920001187 thermosetting polymer Polymers 0.000 description 3
- 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 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
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- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical group OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 2
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- 239000004743 Polypropylene Substances 0.000 description 2
- OFOBLEOULBTSOW-UHFFFAOYSA-N Propanedioic acid Natural products OC(=O)CC(O)=O OFOBLEOULBTSOW-UHFFFAOYSA-N 0.000 description 2
- JUJWROOIHBZHMG-UHFFFAOYSA-N Pyridine Chemical compound C1=CC=NC=C1 JUJWROOIHBZHMG-UHFFFAOYSA-N 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Natural products C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 239000002253 acid Substances 0.000 description 2
- 150000001298 alcohols Chemical class 0.000 description 2
- 150000001336 alkenes Chemical class 0.000 description 2
- 125000003545 alkoxy group Chemical group 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 229920002678 cellulose Polymers 0.000 description 2
- 239000001913 cellulose Substances 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- 229910000423 chromium oxide Inorganic materials 0.000 description 2
- 230000000052 comparative effect Effects 0.000 description 2
- 239000013078 crystal Substances 0.000 description 2
- GHVNFZFCNZKVNT-UHFFFAOYSA-N decanoic acid Chemical compound CCCCCCCCCC(O)=O GHVNFZFCNZKVNT-UHFFFAOYSA-N 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 229910003460 diamond Inorganic materials 0.000 description 2
- 239000010432 diamond Substances 0.000 description 2
- 125000005442 diisocyanate group Chemical group 0.000 description 2
- POULHZVOKOAJMA-UHFFFAOYSA-N dodecanoic acid Chemical compound CCCCCCCCCCCC(O)=O POULHZVOKOAJMA-UHFFFAOYSA-N 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- ZQPPMHVWECSIRJ-MDZDMXLPSA-N elaidic acid Chemical compound CCCCCCCC\C=C\CCCCCCCC(O)=O ZQPPMHVWECSIRJ-MDZDMXLPSA-N 0.000 description 2
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- 239000010439 graphite Substances 0.000 description 2
- 239000012948 isocyanate Substances 0.000 description 2
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 description 2
- 239000000787 lecithin Substances 0.000 description 2
- 235000010445 lecithin Nutrition 0.000 description 2
- 229940067606 lecithin Drugs 0.000 description 2
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- 238000005259 measurement Methods 0.000 description 2
- 238000002156 mixing Methods 0.000 description 2
- 238000013008 moisture curing Methods 0.000 description 2
- WWZKQHOCKIZLMA-UHFFFAOYSA-N octanoic acid Chemical compound CCCCCCCC(O)=O WWZKQHOCKIZLMA-UHFFFAOYSA-N 0.000 description 2
- 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 2
- 239000003973 paint Substances 0.000 description 2
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- 229920001296 polysiloxane Polymers 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- RGTIBVZDHOMOKC-UHFFFAOYSA-N stearolic acid Chemical compound CCCCCCCCC#CCCCCCCCC(O)=O RGTIBVZDHOMOKC-UHFFFAOYSA-N 0.000 description 2
- 229910052712 strontium Inorganic materials 0.000 description 2
- CIOAGBVUUVVLOB-UHFFFAOYSA-N strontium atom Chemical compound [Sr] CIOAGBVUUVVLOB-UHFFFAOYSA-N 0.000 description 2
- 229920003048 styrene butadiene rubber Polymers 0.000 description 2
- VZCYOOQTPOCHFL-UHFFFAOYSA-N trans-butenedioic acid Natural products OC(=O)C=CC(O)=O VZCYOOQTPOCHFL-UHFFFAOYSA-N 0.000 description 2
- 239000013638 trimer Substances 0.000 description 2
- OYHQOLUKZRVURQ-NTGFUMLPSA-N (9Z,12Z)-9,10,12,13-tetratritiooctadeca-9,12-dienoic acid Chemical compound C(CCCCCCC\C(=C(/C\C(=C(/CCCCC)\[3H])\[3H])\[3H])\[3H])(=O)O OYHQOLUKZRVURQ-NTGFUMLPSA-N 0.000 description 1
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 description 1
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 description 1
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 description 1
- 229920002126 Acrylic acid copolymer Polymers 0.000 description 1
- LSNNMFCWUKXFEE-UHFFFAOYSA-M Bisulfite Chemical group OS([O-])=O LSNNMFCWUKXFEE-UHFFFAOYSA-M 0.000 description 1
- 239000005632 Capric acid (CAS 334-48-5) Substances 0.000 description 1
- 239000005635 Caprylic acid (CAS 124-07-2) Substances 0.000 description 1
- 229920001747 Cellulose diacetate Polymers 0.000 description 1
- DQEFEBPAPFSJLV-UHFFFAOYSA-N Cellulose propionate Chemical compound CCC(=O)OCC1OC(OC(=O)CC)C(OC(=O)CC)C(OC(=O)CC)C1OC1C(OC(=O)CC)C(OC(=O)CC)C(OC(=O)CC)C(COC(=O)CC)O1 DQEFEBPAPFSJLV-UHFFFAOYSA-N 0.000 description 1
- 229910000531 Co alloy Inorganic materials 0.000 description 1
- JOYRKODLDBILNP-UHFFFAOYSA-N Ethyl urethane Chemical compound CCOC(N)=O JOYRKODLDBILNP-UHFFFAOYSA-N 0.000 description 1
- YCKRFDGAMUMZLT-UHFFFAOYSA-N Fluorine atom Chemical compound [F] YCKRFDGAMUMZLT-UHFFFAOYSA-N 0.000 description 1
- CTKINSOISVBQLD-UHFFFAOYSA-N Glycidol Chemical compound OCC1CO1 CTKINSOISVBQLD-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 239000005639 Lauric acid Substances 0.000 description 1
- 239000004640 Melamine resin Substances 0.000 description 1
- 229920000877 Melamine resin Polymers 0.000 description 1
- 229920001730 Moisture cure polyurethane Polymers 0.000 description 1
- 229920000459 Nitrile rubber Polymers 0.000 description 1
- 239000000020 Nitrocellulose Substances 0.000 description 1
- CTQNGGLPUBDAKN-UHFFFAOYSA-N O-Xylene Chemical compound CC1=CC=CC=C1C CTQNGGLPUBDAKN-UHFFFAOYSA-N 0.000 description 1
- 239000005642 Oleic acid Substances 0.000 description 1
- 229910019142 PO4 Inorganic materials 0.000 description 1
- 239000005062 Polybutadiene Substances 0.000 description 1
- 239000004695 Polyether sulfone Substances 0.000 description 1
- 239000004721 Polyphenylene oxide Substances 0.000 description 1
- 235000021355 Stearic acid Nutrition 0.000 description 1
- XSTXAVWGXDQKEL-UHFFFAOYSA-N Trichloroethylene Chemical compound ClC=C(Cl)Cl XSTXAVWGXDQKEL-UHFFFAOYSA-N 0.000 description 1
- 229920001807 Urea-formaldehyde Polymers 0.000 description 1
- 229920002433 Vinyl chloride-vinyl acetate copolymer Polymers 0.000 description 1
- 150000008065 acid anhydrides Chemical class 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 239000012190 activator Substances 0.000 description 1
- 230000000996 additive effect Effects 0.000 description 1
- 150000001338 aliphatic hydrocarbons Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 125000003342 alkenyl group Chemical group 0.000 description 1
- 150000003973 alkyl amines Chemical class 0.000 description 1
- 125000002947 alkylene group Chemical group 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
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 1
- 150000001408 amides Chemical class 0.000 description 1
- 150000001413 amino acids Chemical class 0.000 description 1
- 150000001414 amino alcohols Chemical class 0.000 description 1
- 239000003945 anionic surfactant Substances 0.000 description 1
- 229910052788 barium Inorganic materials 0.000 description 1
- KYAZRUPZRJALEP-UHFFFAOYSA-N bismuth manganese Chemical compound [Mn].[Bi] KYAZRUPZRJALEP-UHFFFAOYSA-N 0.000 description 1
- NTXGQCSETZTARF-UHFFFAOYSA-N buta-1,3-diene;prop-2-enenitrile Chemical compound C=CC=C.C=CC#N NTXGQCSETZTARF-UHFFFAOYSA-N 0.000 description 1
- 229910052791 calcium Inorganic materials 0.000 description 1
- 239000011575 calcium Substances 0.000 description 1
- WETINTNJFLGREW-UHFFFAOYSA-N calcium;iron;tetrahydrate Chemical compound O.O.O.O.[Ca].[Fe].[Fe] WETINTNJFLGREW-UHFFFAOYSA-N 0.000 description 1
- BVKZGUZCCUSVTD-UHFFFAOYSA-N carbonic acid Chemical compound OC(O)=O BVKZGUZCCUSVTD-UHFFFAOYSA-N 0.000 description 1
- 150000001732 carboxylic acid derivatives Chemical group 0.000 description 1
- 239000003093 cationic surfactant Substances 0.000 description 1
- 229920002301 cellulose acetate Polymers 0.000 description 1
- 229920006218 cellulose propionate Polymers 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
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- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000001723 curing Methods 0.000 description 1
- 208000028659 discharge Diseases 0.000 description 1
- 235000013399 edible fruits Nutrition 0.000 description 1
- 229910001651 emery Inorganic materials 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 150000002148 esters Chemical class 0.000 description 1
- RTZKZFJDLAIYFH-UHFFFAOYSA-N ether Substances CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 1
- 239000011737 fluorine Substances 0.000 description 1
- 229910052731 fluorine Inorganic materials 0.000 description 1
- 229920005546 furfural resin Polymers 0.000 description 1
- 239000002223 garnet Substances 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 229920000578 graft copolymer Polymers 0.000 description 1
- 238000009499 grossing Methods 0.000 description 1
- 125000000623 heterocyclic group Chemical group 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 150000003949 imides Chemical class 0.000 description 1
- 150000002484 inorganic compounds Chemical class 0.000 description 1
- 229910010272 inorganic material Inorganic materials 0.000 description 1
- XMNVMZIXNKZAJB-UHFFFAOYSA-N iron(3+);lead(2+);oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[O-2].[O-2].[Fe+3].[Fe+3].[Pb+2].[Pb+2] XMNVMZIXNKZAJB-UHFFFAOYSA-N 0.000 description 1
- SZVJSHCCFOBDDC-UHFFFAOYSA-N iron(II,III) oxide Inorganic materials O=[Fe]O[Fe]O[Fe]=O SZVJSHCCFOBDDC-UHFFFAOYSA-N 0.000 description 1
- 238000004898 kneading Methods 0.000 description 1
- 239000000696 magnetic material Substances 0.000 description 1
- 239000002075 main ingredient Substances 0.000 description 1
- VZCYOOQTPOCHFL-UPHRSURJSA-N maleic acid Chemical compound OC(=O)\C=C/C(O)=O VZCYOOQTPOCHFL-UPHRSURJSA-N 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 238000000034 method Methods 0.000 description 1
- CWQXQMHSOZUFJS-UHFFFAOYSA-N molybdenum disulfide Chemical compound S=[Mo]=S CWQXQMHSOZUFJS-UHFFFAOYSA-N 0.000 description 1
- 229910052982 molybdenum disulfide Inorganic materials 0.000 description 1
- 229920001220 nitrocellulos Polymers 0.000 description 1
- 239000002736 nonionic surfactant Substances 0.000 description 1
- 229920003986 novolac Polymers 0.000 description 1
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 1
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 1
- 229960002446 octanoic acid Drugs 0.000 description 1
- 150000002894 organic compounds Chemical class 0.000 description 1
- FUGYGGDSWSUORM-UHFFFAOYSA-N para-hydroxystyrene Natural products OC1=CC=C(C=C)C=C1 FUGYGGDSWSUORM-UHFFFAOYSA-N 0.000 description 1
- FDPIMTJIUBPUKL-UHFFFAOYSA-N pentan-3-one Chemical compound CCC(=O)CC FDPIMTJIUBPUKL-UHFFFAOYSA-N 0.000 description 1
- MOQRZWSWPNIGMP-UHFFFAOYSA-N pentyl octadecanoate Chemical compound CCCCCCCCCCCCCCCCCC(=O)OCCCCC MOQRZWSWPNIGMP-UHFFFAOYSA-N 0.000 description 1
- 235000021317 phosphate Nutrition 0.000 description 1
- 125000005496 phosphonium group Chemical group 0.000 description 1
- 125000002270 phosphoric acid ester group Chemical group 0.000 description 1
- 150000003014 phosphoric acid esters Chemical class 0.000 description 1
- 239000000049 pigment Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920000233 poly(alkylene oxides) Polymers 0.000 description 1
- 229920001084 poly(chloroprene) Polymers 0.000 description 1
- 229920003207 poly(ethylene-2,6-naphthalate) Polymers 0.000 description 1
- 229920002037 poly(vinyl butyral) polymer Polymers 0.000 description 1
- 229920000768 polyamine Polymers 0.000 description 1
- 229920002857 polybutadiene Polymers 0.000 description 1
- 229920000515 polycarbonate Polymers 0.000 description 1
- 239000004417 polycarbonate Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920001225 polyester resin Polymers 0.000 description 1
- 239000004645 polyester resin Substances 0.000 description 1
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- 229920006393 polyether sulfone Polymers 0.000 description 1
- 239000011112 polyethylene naphthalate Substances 0.000 description 1
- 229920001195 polyisoprene Polymers 0.000 description 1
- 238000006116 polymerization reaction Methods 0.000 description 1
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- 229920001343 polytetrafluoroethylene Polymers 0.000 description 1
- 239000004810 polytetrafluoroethylene Substances 0.000 description 1
- 229920002620 polyvinyl fluoride Polymers 0.000 description 1
- 230000002265 prevention Effects 0.000 description 1
- UMJSCPRVCHMLSP-UHFFFAOYSA-N pyridine Natural products COC1=CC=CN=C1 UMJSCPRVCHMLSP-UHFFFAOYSA-N 0.000 description 1
- 150000003242 quaternary ammonium salts Chemical class 0.000 description 1
- 239000001397 quillaja saponaria molina bark Substances 0.000 description 1
- 229920003987 resole Polymers 0.000 description 1
- 229930182490 saponin Natural products 0.000 description 1
- 150000007949 saponins Chemical class 0.000 description 1
- HBMJWWWQQXIZIP-UHFFFAOYSA-N silicon carbide Chemical compound [Si+]#[C-] HBMJWWWQQXIZIP-UHFFFAOYSA-N 0.000 description 1
- 229910010271 silicon carbide Inorganic materials 0.000 description 1
- 229920002545 silicone oil Polymers 0.000 description 1
- 239000000344 soap Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000010935 stainless steel Substances 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000008117 stearic acid Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- IIACRCGMVDHOTQ-UHFFFAOYSA-N sulfamic acid Chemical class NS(O)(=O)=O IIACRCGMVDHOTQ-UHFFFAOYSA-N 0.000 description 1
- RWSOTUBLDIXVET-UHFFFAOYSA-O sulfonium group Chemical group [SH3+] RWSOTUBLDIXVET-UHFFFAOYSA-O 0.000 description 1
- 229920003051 synthetic elastomer Polymers 0.000 description 1
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- 239000000057 synthetic resin Substances 0.000 description 1
- 239000005061 synthetic rubber Substances 0.000 description 1
- 239000000454 talc Substances 0.000 description 1
- 229910052623 talc Inorganic materials 0.000 description 1
- TUNFSRHWOTWDNC-HKGQFRNVSA-N tetradecanoic acid Chemical compound CCCCCCCCCCCCC[14C](O)=O TUNFSRHWOTWDNC-HKGQFRNVSA-N 0.000 description 1
- ITRNXVSDJBHYNJ-UHFFFAOYSA-N tungsten disulfide Chemical compound S=[W]=S ITRNXVSDJBHYNJ-UHFFFAOYSA-N 0.000 description 1
- 229920006337 unsaturated polyester resin Polymers 0.000 description 1
- 239000000080 wetting agent Substances 0.000 description 1
- 239000008096 xylene Substances 0.000 description 1
- 239000004711 α-olefin Substances 0.000 description 1
Landscapes
- Magnetic Record Carriers (AREA)
- Paints Or Removers (AREA)
Abstract
Description
【発明の詳細な説明】
〔産業上の利用分野〕
本発明は磁気特性の経時安定性に優れた磁気記録媒体、
特に六方晶平板状で平板面に垂直方向に磁化容易軸を有
する強磁性体を含有し、抗磁力の経時安定性が著しく改
良された磁気記録媒体に関する。[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a magnetic recording medium with excellent stability of magnetic properties over time;
In particular, the present invention relates to a magnetic recording medium containing a ferromagnetic material having a hexagonal flat plate shape and having an axis of easy magnetization perpendicular to the flat plate surface, and having significantly improved stability of coercive force over time.
従来、磁気記録再生にはγ−Ｆ ｅ ２０ ａ 、Ｃｒ
Ｏ□等の針状結晶からなる強磁性体を結合剤中に分散
させた磁性層を非磁性支持体上て設けた磁気記録媒体が
広く用いられている。Conventionally, γ-F e 20 a , Cr
Magnetic recording media in which a magnetic layer in which a ferromagnetic material consisting of needle-like crystals such as O□ is dispersed in a binder are provided on a nonmagnetic support are widely used.
しかし最近、記録の大容量化、小型化を達成するため記
録密度の向上が強く要望されているが。Recently, however, there has been a strong demand for improved recording density in order to achieve larger recording capacity and smaller size.
従来のような針状磁性粉を用いて高密度記録に適する記
録媒体を得るには針状磁性粉の最大寸法を記録波長、あ
るいは記録ピッド長よりも十分小さくする必要がある。In order to obtain a recording medium suitable for high-density recording using conventional acicular magnetic powder, it is necessary to make the maximum dimension of the acicular magnetic powder sufficiently smaller than the recording wavelength or recording pit length.
現在針状磁性粉として、０．３μｍ程度の寸法のものが
すでに実用に供されており、最短記録波長的１μｍが得
られている。Currently, acicular magnetic powder with a size of about 0.3 μm is already in practical use, and a shortest recording wavelength of 1 μm has been obtained.
今後さらに高密度の記録が可能な媒体を得るには、さら
疋−層針状磁性粉の寸法を小さくする必要がある。しか
しそのような小さな針状磁性粉においては太さが１００
Ａ以下ときわめて細くなり、粒子体積としても１Ｏ−１
７ｃｒｒＬ３以下ときわめて小さくなるため、熱擾乱１
表面の効果によって磁気特性が低下し、又磁性塗膜に磁
界を加えても十分な配向が得られないなどの問題がある
。In order to obtain a medium capable of recording at even higher density in the future, it is necessary to reduce the dimensions of the acicular magnetic powder. However, such small needle-shaped magnetic powder has a thickness of 100 mm.
It is extremely thin, less than A, and has a particle volume of 1O-1.
Thermal disturbance 1 is extremely small, less than 7crrL3.
There are problems in that the magnetic properties deteriorate due to surface effects, and sufficient orientation cannot be obtained even when a magnetic field is applied to the magnetic coating.
近年このような欠点を解消するために、平板状で板面に
垂直な方向に磁化容易軸を有する六方晶フェライトを強
磁性体として用いる磁気記録媒体が開発された（例えば
特開昭５８−６５２５号、同５８−６５２６号など）。In recent years, in order to eliminate these drawbacks, magnetic recording media have been developed that use flat plate-shaped hexagonal ferrite, which has an axis of easy magnetization in the direction perpendicular to the plate surface, as a ferromagnetic material (e.g., JP-A-58-6525). No. 58-6526, etc.).
しかしながら、本発明はこのような六方晶７エライトを
用いた磁気記録媒体は抗磁力の経時変化が犬で、例えば
第１図に例示したように、製造時に抗磁力（Ｈｃ）が約
６０００ｅであったＣ〇−置換Ｂａ−フェライト含有垂
直磁気記録媒体を室温（２３℃）で６０％ＲＨの条件下
で放置すると、１２ケ月後にはＨｃが約６８００ｅに達
し、次後徐々にではあるがＨａは増加を続は数年後に飽
和値である７２５０ｅ Ｋ近づいてゆくことを知った。However, in the present invention, the magnetic recording medium using such hexagonal heptagonal crystal 7-elite has a significant change in coercive force over time, and for example, as illustrated in FIG. When a perpendicular magnetic recording medium containing C-substituted Ba-ferrite is left at room temperature (23°C) and 60% RH, Hc reaches approximately 6800e after 12 months, and then Ha gradually decreases. I learned that as the temperature continues to increase, it will approach the saturation value of 7250e K in a few years.
（本発明では。(In the present invention.
このような飽和値をその記録媒体の最大抗磁力と称する
。）
このような抗磁力の変化は、その磁気記録媒体の最適記
録電流を変化させ、最適の出力が得られない。すなわち
、ある時点でその記録媒体の最適記録電流を測定し、最
適の出力が得られるようにヘッドに流す記録電流値を設
定しておいても数ケ月経つと抗磁力が経時変化を生じて
いるので最適の出力が得られなくなる。Such a saturation value is called the maximum coercive force of the recording medium. ) Such a change in coercive force changes the optimum recording current of the magnetic recording medium, making it impossible to obtain the optimum output. In other words, even if you measure the optimal recording current for the recording medium at a certain point and set the recording current value to flow through the head so as to obtain the optimal output, the coercive force will change over time after several months. Therefore, optimal output cannot be obtained.
また、Ｈａが上がると重ね書き特性も劣化すると云う欠
点もある。Furthermore, there is also the drawback that as Ha increases, overwriting characteristics also deteriorate.
従って、本発明の目的は上記欠点を解消した磁気記録媒
体を提供することにある。Therefore, an object of the present invention is to provide a magnetic recording medium that eliminates the above-mentioned drawbacks.
すなわち、本発明の目的は、六方晶平板状で平板面に垂
直方向に磁化容易軸を有する強磁性体を含有し、抗磁力
の経時安定性が著しく改良された磁気記録媒体を提供す
ることにある。That is, an object of the present invention is to provide a magnetic recording medium that contains a ferromagnetic material that has a hexagonal flat plate shape and has an axis of easy magnetization perpendicular to the flat plate surface, and has significantly improved stability of coercive force over time. be.
本発明者は鋭意研究を重ねた結果、上記した如き磁気記
録媒体において、製造後早期に該記録媒体を加熱処理等
を行なってその抗磁力を強制的に上昇させておくことに
よって前記目的を達成することができた。As a result of intensive research, the inventor of the present invention has achieved the above object by forcibly increasing the coercive force of the magnetic recording medium as described above by subjecting the recording medium to heat treatment or the like at an early stage after manufacture. We were able to.
すなわち本発明は大方晶平板状で平板面に垂直方向ＶＣ
出化容易軸を有する強磁性体粉末を結合剤中に分散させ
た磁性層を非磁性支持体上に設けてなる磁気記録媒体に
おいて、該磁気記録媒体の抗磁力が加熱処理によって強
制的に変化させられ、加熱処理終了後から、磁気記録媒
体製造後６ケ月迄の各時点における抗磁力とその後の最
大抗磁力との差が最大抗磁力に対し１０％以内になるよ
うにしたことを特徴とする磁気記録媒体である。That is, the present invention has a macrogonal planar shape and a direction VC perpendicular to the planar surface.
In a magnetic recording medium in which a magnetic layer in which ferromagnetic powder having an easy-to-detach axis is dispersed in a binder is provided on a non-magnetic support, the coercive force of the magnetic recording medium is forcibly changed by heat treatment. and the difference between the coercive force at each point in time from the end of the heat treatment up to 6 months after manufacturing the magnetic recording medium and the subsequent maximum coercive force is within 10% of the maximum coercive force. It is a magnetic recording medium.
以下、本発明の詳細な説明する。The present invention will be explained in detail below.
本発明における磁気記録媒体は六方晶平板状の強磁性体
が結合剤中て分散された磁性層が非磁性支持体上に設け
られた基本構造を有するものである。The magnetic recording medium of the present invention has a basic structure in which a magnetic layer in which a hexagonal flat plate-shaped ferromagnetic material is dispersed in a binder is provided on a nonmagnetic support.
本発明で使用する非磁性支持体圧は特に制限はなく１通
常使用されているものを用いることができる。非磁性支
持体を形成する素材の例としては、ポリエチレンテレフ
タレート、ポリエチレン、ポリプロピレン、ポリカーボ
ネート、ポリエチレンナフタレート、ポリアミド９１ホ
リアミト９イミド。The pressure of the nonmagnetic support used in the present invention is not particularly limited, and any commonly used pressure may be used. Examples of materials forming the nonmagnetic support include polyethylene terephthalate, polyethylene, polypropylene, polycarbonate, polyethylene naphthalate, and polyamide 91 polyamide 9 imide.
ポリイミｒ、ホリサルホン、ポリエーテルサルホンなど
の各種の合成樹脂のフィルム、およびアルミ箔、ステン
レス箔などの金属箔を挙げることができる。また、非磁
性支持体は、一般には厚みが３〜５０μｍ、好ましくは
５〜３０μｍのものが使用される。Examples include films of various synthetic resins such as polyimir, folysulfone, and polyethersulfone, and metal foils such as aluminum foil and stainless steel foil. Further, the nonmagnetic support used generally has a thickness of 3 to 50 μm, preferably 5 to 30 μm.
本発明に用いられる六方晶平板状で平板面に垂直方向に
磁化容易軸を有する強磁性体としては、例えば六方晶フ
ェライト粉末、すなわち、バリウムフェライト、ストロ
ンチウムフェライト、鉛フェライト、カルシウムフェラ
イトの各置換体、マンガンビスマス、六方晶コバルト合
金などがあげられ、特に好ましいものとしては、バリウ
ムフェライト、ストロンチウムフェライトの各Ｃｏ Ｕ
携体がある。本発明のこの大方晶平板状の強磁性体は板
径（平均粒後）が０．０１〜１０μｍで特に好ましいの
は、０．０３〜０．１０μｍであり板厚（平均厚さ）１
”ｔ Ｏ，００５〜５ μｍで特に好ましいのは０．０
１５〜０．０５μｍである。Examples of the ferromagnetic material used in the present invention, which has a hexagonal flat plate shape and has an axis of easy magnetization perpendicular to the flat plate surface, include hexagonal ferrite powder, i.e., substituted substances of barium ferrite, strontium ferrite, lead ferrite, and calcium ferrite. , manganese bismuth, and hexagonal cobalt alloys. Particularly preferable ones include barium ferrite and strontium ferrite.
I have a mobile phone. The orthogonal tabular ferromagnetic material of the present invention has a plate diameter (after the average grain) of 0.01 to 10 μm, particularly preferably 0.03 to 0.10 μm, and a plate thickness (average thickness) of 1
”t O,005 to 5 μm, particularly preferably 0.0
It is 15 to 0.05 μm.
本発明における磁性層には、前記の強磁性体の他に結合
剤、添加剤が加えられてもよい。In addition to the ferromagnetic material described above, a binder and additives may be added to the magnetic layer in the present invention.
添加剤として、分散剤、潤滑剤、研磨剤、帯電防止剤等
が加えられてもよい。As additives, dispersants, lubricants, abrasives, antistatic agents, etc. may be added.
大発明に使用される結合剤としては従来公知の熱可塑性
樹脂、熱硬化性樹脂又は反応型樹脂やこれらの混合物が
使用される。As the binder used in the present invention, conventionally known thermoplastic resins, thermosetting resins, reactive resins, and mixtures thereof are used.
熱可塑性樹脂として軟化温度が１５０℃以下、平均分子
量が１０．０００〜２００，０００、重合度が約２００
〜２０００程度のもので、例えば塩化ビニル酢酸ビニル
共重合体、塩化ビニル酢酸ビニルマレイン酸共重合体、
塩化ビニル塩化ビニリデン共重合体、塩化ビニルアクリ
ロニトリル共重合体、アクリル酸エステルアクリロニト
リル共重合体、マクリル酸エステル塩化ビニリチン共重
合体、アクリル酸エステルスチレン共重合体、メタクリ
ル酸エステルアクリロニトリル共重合体、メタクリル酸
エステル塩化ビニリデン共重合体、メタクリル酸エステ
ルスチレン共重合体、ウレタンニジストマー、ポリ弗化
ビニル、塩化ビニリデンアクリロニトリル共重合体、ブ
タジェンアクリロニトリル共重合体、ポリアミド樹脂、
ポリビニルブチラール、セルロース誘Ｎ体（セルロース
アセテートフチレート、セルロースダイアセテート、セ
ルローストリアセデート、セルロースプロピオネート、
ニトロセルロース等）、スチレンブタジェン共重合体。As a thermoplastic resin, the softening temperature is 150°C or less, the average molecular weight is 10.000 to 200,000, and the degree of polymerization is about 200.
~2000, such as vinyl chloride vinyl acetate copolymer, vinyl chloride vinyl acetate maleic acid copolymer,
Vinyl chloride vinylidene chloride copolymer, vinyl chloride acrylonitrile copolymer, acrylic acid ester acrylonitrile copolymer, acrylic acid ester vinylitine chloride copolymer, acrylic acid ester styrene copolymer, methacrylic acid ester acrylonitrile copolymer, methacrylic acid Ester vinylidene chloride copolymer, methacrylic acid ester styrene copolymer, urethane distomer, polyvinyl fluoride, vinylidene chloride acrylonitrile copolymer, butadiene acrylonitrile copolymer, polyamide resin,
Polyvinyl butyral, cellulose derivatives (cellulose acetate phthylate, cellulose diacetate, cellulose triacedate, cellulose propionate,
(nitrocellulose, etc.), styrene-butadiene copolymer.
ポリエステル樹脂、各種の合成ゴム系の熱可塑性樹脂（
ポリブタジェン、ポリクロロプレン、ポリイソプレン、
スチレンブタジェン共重合体など）及びこれらの混合物
等が使用される。Polyester resin, various synthetic rubber-based thermoplastic resins (
polybutadiene, polychloroprene, polyisoprene,
styrene-butadiene copolymer, etc.) and mixtures thereof.
熱硬化性樹脂又は反応型樹脂としては塗布液の状態では
２００．０００以下の分子量であり、塗布、乾燥後に添
加することにより、縮合、付加等の反応によシ分子量は
無限大のものとなる。又、これらの樹脂のなかで、樹脂
が熱分解するまでの間に軟化又は溶融しないものが好ま
しい。具体的には例、ｔばフェノール・ホルマリン−ノ
ボラック樹脂、フェノール・ホルマリン−レゾール樹脂
、フェノール・フルフラール樹脂、キシレン・ホルムア
ルデヒド樹脂、尿素樹脂、メラミン樹脂、乾性油変性ア
ルキッド樹脂１石炭酸樹脂変性アルキッド樹脂、マレイ
ン酸樹脂変性アルキッド樹脂、不飽和ポリエステル樹脂
、エポキシ樹脂と硬化剤（ポリアミン、酸無水物、ポリ
アミド樹脂、その他）、末端イソシアネートポリエステ
ル湿気硬化型樹脂、末端イソシアネートポリエーテル湿
気硬化型樹脂、ポリイソシアネートプレポリマー（：）
インシアネートと低分子針トリオールとを反応させて得
た１分子内に３ヶ以上のイソシアネート基を有する化合
物、ジイソシアネートのトリマー及びテトラマー）、ポ
リイソシアネートプレポリマーと活性水素含有する樹脂
（ポリエステルポリオール、ポリエーテルポリオール、
アクリル酸共重合体、マレイン酸共重合体、２−ヒビロ
キシエチルメタクリレート共重合体、パラヒドロキシス
チレン共重合体、その他）、及びこれらの混合物等であ
る。As a thermosetting resin or a reactive resin, it has a molecular weight of 200,000 or less in the state of a coating solution, but when added after coating and drying, the molecular weight becomes infinite due to reactions such as condensation and addition. . Also, among these resins, those that do not soften or melt before the resin is thermally decomposed are preferred. Specifically, examples include phenol/formalin-novolak resin, phenol/formalin-resol resin, phenol/furfural resin, xylene/formaldehyde resin, urea resin, melamine resin, drying oil-modified alkyd resin, 1) carbonic acid resin-modified alkyd resin, Maleic acid resin modified alkyd resin, unsaturated polyester resin, epoxy resin and curing agent (polyamine, acid anhydride, polyamide resin, etc.), terminal isocyanate polyester moisture-curing resin, terminal isocyanate polyether moisture-curing resin, polyisocyanate pre polymer(:)
Compounds having three or more isocyanate groups in one molecule obtained by reacting incyanate and low molecular needle triol, diisocyanate trimers and tetramers), polyisocyanate prepolymers and active hydrogen-containing resins (polyester polyols, polyester polyols, diisocyanate trimers and tetramers), ether polyol,
acrylic acid copolymers, maleic acid copolymers, 2-hydroxyethyl methacrylate copolymers, parahydroxystyrene copolymers, etc.), and mixtures thereof.
上記結合剤のうち、本発明の強磁性体と組合せて最も良
好な結果を示すのは塩化ビニル酢酸ビニル無水マレイン
酸共重合体である。Among the above binders, vinyl chloride vinyl acetate maleic anhydride copolymer shows the best results in combination with the ferromagnetic material of the present invention.
これらの結合剤の単独又は組合わされたものが使われ、
他に添加剤が加えられる。強磁性体と結合剤との混合割
合は重量比で強磁性体１００重量部に対して結合剤８〜
４００重量部、好ましくは１０〜２００重量部の範囲で
使用される。These binders may be used alone or in combination;
Other additives may be added. The mixing ratio of the ferromagnetic material and the binder is 8 to 8 parts by weight of the binder to 100 parts by weight of the ferromagnetic material.
It is used in an amount of 400 parts by weight, preferably 10 to 200 parts by weight.
分散剤（顔料湿潤剤）としてはカプリル酸、カプリン酸
、ラウリン酸、ミリスチン酸、バルミチン酸、ステアリ
ン酸、オレイン酸、エライジン酸、リノール酸、リルン
酸、ステアロール酸等の炭素数１２〜１８個の脂肪酸（
ＲＣ００Ｉ（、Ｒ１は炭素数１１〜１７個のアルキルま
たはアルケニル基）；前記の脂肪酸のアルカリ金属（Ｌ
５ Ｎａ、に等）またはアルカリ土類金属（Ｍｇ、
Ｃａ、 Ｂａ）から成る金属石鹸；前記の脂肪酸エステ
ルの弗素を含有した化合物；前記の脂肪酸のアミド；ポ
リアルキレンオキサイドアルキルリン酸エステル；レシ
チン；トリアルキルポリオレフィンオキシ第四アンモニ
ウム塩（アルキルは炭素数１〜５個、オレフィンはエチ
レン、プロピレンなど）；等が使用される。Dispersants (pigment wetting agents) include caprylic acid, capric acid, lauric acid, myristic acid, valmitic acid, stearic acid, oleic acid, elaidic acid, linoleic acid, lylunic acid, stearolic acid, etc. having 12 to 18 carbon atoms. fatty acids (
RC00I (, R1 is an alkyl or alkenyl group having 11 to 17 carbon atoms);
5 Na, etc.) or alkaline earth metals (Mg, etc.)
Metal soaps consisting of Ca, Ba); fluorine-containing compounds of the above fatty acid esters; amides of the above fatty acids; polyalkylene oxide alkyl phosphates; lecithin; trialkyl polyolefin oxy quaternary ammonium salts (alkyl has 1 carbon number -5 olefins (olefins such as ethylene, propylene, etc.); etc. are used.
この他に炭素数１２以上の高級アルコール、およびこれ
らの他に硫酸エステル等も使用可能である。In addition, higher alcohols having 12 or more carbon atoms and sulfuric esters may also be used.
これらの分散剤は結合剤１００重量部に対して０．５〜
２０重量部の範囲で添加される。These dispersants are used in an amount of 0.5 to 100 parts by weight of the binder.
It is added in an amount of 20 parts by weight.
潤滑剤としてはジアルキルポリシロキサン（アルキルは
炭素数１〜５個）、ジアルコキシポリシロキサン（アル
コキシは炭素数１〜４個）、モノアルキルモノアルコキ
シポリシロキサン（アルキルは炭素数１〜５個、アルコ
キシは炭素数１〜４個）、フェニルポリシロキサン、フ
ロロアルキルポリシロキサン（アルキルは炭素数１〜５
個）などのシリコンオイル；グラファイトなどの導電性
微粉末；二硫化モリブデン、二硫化タングステンなどの
無機微粉末；ポリエチレン、ポリプロピレン、ポリエチ
レン塩化ビニル共重合体、ポリテトラフルオロエチレン
などのプラスチック微粉末；α−オレフィン重合物；常
温で液状の不飽和脂肪族炭化水素（ｎ−オレフィン二重
結合が末端の炭素に結合した化合物、炭素数約２ＯＬ炭
素数１２〜２０個の一塩基性脂肪酸と炭素数３〜１２個
の一価のアルコールから成る脂肪酸エステル類、フルオ
ロカーボン類などが使用できる。これらの潤滑剤は結合
剤１００重量部に対して０．２〜２０重量部の範囲で添
加される。As a lubricant, dialkyl polysiloxane (alkyl has 1 to 5 carbon atoms), dialkoxypolysiloxane (alkoxy has 1 to 4 carbon atoms), monoalkyl monoalkoxy polysiloxane (alkyl has 1 to 5 carbon atoms, alkoxy has 1 to 4 carbon atoms), phenylpolysiloxane, fluoroalkylpolysiloxane (alkyl has 1 to 5 carbon atoms)
conductive fine powder such as graphite; inorganic fine powder such as molybdenum disulfide and tungsten disulfide; fine plastic powder such as polyethylene, polypropylene, polyethylene vinyl chloride copolymer, polytetrafluoroethylene; α -Olefin polymer; unsaturated aliphatic hydrocarbon that is liquid at room temperature (compound in which an n-olefin double bond is bonded to the terminal carbon, about 2 carbon atoms, monobasic fatty acid with 12 to 20 carbon atoms and 3 carbon atoms) Fatty acid esters consisting of ~12 monohydric alcohols, fluorocarbons, etc. can be used.These lubricants are added in an amount of 0.2 to 20 parts by weight based on 100 parts by weight of the binder.
研磨剤としては一般に使用される材料で溶融アルミナ、
炭化ケイ素、酸化クロム（Ｃｒ ２０３）、コランダム
、人造コランダム、ダイアモンド、人造ダイアモンド、
ザクロ石、エメリー（主成分：コランダムと磁鉄鉱）等
が使用される。こねらの研磨剤はモース硬度が５以上で
あり、平均粒子径が０．０５〜５μの大きさのものが使
用され、特に好ましくは０．１〜２μである。これらの
研磨剤は結合剤１００重量部に対して０．５〜２０重量
部の範囲で添加される。Commonly used abrasive materials include fused alumina,
Silicon carbide, chromium oxide (Cr 203), corundum, artificial corundum, diamond, artificial diamond,
Garnet, emery (main ingredients: corundum and magnetite), etc. are used. The Konera abrasive has a Mohs hardness of 5 or more and an average particle size of 0.05 to 5 μm, particularly preferably 0.1 to 2 μm. These abrasives are added in an amount of 0.5 to 20 parts by weight based on 100 parts by weight of the binder.
帯電防止剤としてはカーボンブラック、カーボンブラッ
クグラフトポリマーなどの導電性微粉末；サポニンなど
の天然界面活性剤；アルキレンオキサイド系、グリセリ
ン系、グリシド−ル系などのノニオン界面活性剤；高級
アルキルアミン類、第４級アンモニウム塩類、ピリジン
その他の複素環類、ホスホニウム又はスルホニウム類な
どのカチオン界面活性剤；カルボン酸、スルホン酸、燐
酸、硫酸エステル基、燐酸エステル基等の酸性基を含む
アニオン界面活性剤；アミノ酸類、アミノスルホン酸類
、アミノアルコールの硫酸または燐酸エステル類等の両
性活性剤などが使用される。Antistatic agents include conductive fine powder such as carbon black and carbon black graft polymer; natural surfactants such as saponin; nonionic surfactants such as alkylene oxide, glycerin, and glycidol; higher alkylamines, Cationic surfactants such as quaternary ammonium salts, pyridine and other heterocycles, phosphoniums or sulfoniums; Anionic surfactants containing acidic groups such as carboxylic acid, sulfonic acid, phosphoric acid, sulfuric acid ester groups, and phosphoric acid ester groups; Ampholytic activators such as amino acids, aminosulfonic acids, sulfuric acid or phosphoric acid esters of amino alcohols, etc. are used.
上記の導電性微粉末は結合剤１００重量部に対して０．
２〜２０重量部が、界面活性剤は０．１〜１０重量部の
範囲で添加される。The above conductive fine powder is 0.0% per 100 parts by weight of the binder.
The surfactant is added in an amount of 0.1 to 10 parts by weight.
これらの界面活性剤は単独または混合して添加してもよ
い。これらは帯電防止剤として用いられるものであるが
、時としてその他の目的、たとえば分散、磁気特性の改
良５潤滑性の改良、塗布助剤として適用される場合もあ
る。These surfactants may be added alone or in combination. Although these are used as antistatic agents, they are sometimes used for other purposes, such as dispersion, improving magnetic properties, improving lubricity, and as coating aids.
本発明の磁気記録媒体は六方晶平板状強磁性体を、前記
の結合剤、添加剤及び溶剤等に混線分散した磁性塗料を
非磁性支持体上に塗布、配向、乾燥し、必要に応じて表
面平滑化処理を施こした後に、本発明による加熱処理を
施こすことによって得られる。The magnetic recording medium of the present invention is prepared by coating a hexagonal flat plate-shaped ferromagnetic material with a magnetic paint in which cross-dispersion is carried out in the binder, additives, solvent, etc. described above on a non-magnetic support, orienting it, drying it, and then applying it as necessary. It is obtained by performing a heat treatment according to the present invention after performing a surface smoothing treatment.
磁性塗料の混線分散や塗布は従来当該分野で行われてい
る手段をすべて用いることができる。配向は必要に応じ
て磁場配向によって垂直配向す々わち、六方晶平板状強
磁性体の平板面に垂直方向にｆ！ｒｌ場配向する。For crosstalk dispersion and application of the magnetic paint, any means conventionally used in the field can be used. The orientation is perpendicular to the plane of the hexagonal plate-shaped ferromagnetic material by the magnetic field alignment as required, that is, f! rl field orientation.
磁性層は乾燥厚で約０．５〜１２μｍの範囲となるよう
に塗布する。The magnetic layer is coated to have a dry thickness of about 0.5 to 12 μm.
本発明においては、上記のようにして磁性層を塗布乾燥
した磁気記録媒体にその製造後１０日から６ケ月の間の
抗磁力と最大抗磁力との差が最大抗磁力に対し１０％以
内になるように強制的に加熱処理する。上記の磁気記録
媒体はそのままでは、例えば第１図Ａ及びＥＫ例示した
ように、製造後抗磁力が経時的に上昇する。この上昇は
特に製造後約６ケ月以内の期間が著しく、その後も徐々
に上昇し、この傾向が数年間続くことが確認されている
。In the present invention, the difference between the coercive force and the maximum coercive force is within 10% of the maximum coercive force for a period of 10 days to 6 months after manufacture of a magnetic recording medium coated with a magnetic layer and dried as described above. Forced heat treatment to achieve this. If the above-mentioned magnetic recording medium is left as it is, the coercive force increases over time after manufacture, as illustrated in FIGS. 1A and 1E, for example. This increase is particularly noticeable within about 6 months after production, and it has been confirmed that the price will gradually increase thereafter, and this trend will continue for several years.
本発明者は、このような磁気記録媒体を製造直後かまた
は製造後約１０日以内の適当な時期に４０〜１５０℃で
約１０日〜３０分間の加熱処理を行うと、その記録媒体
の製造後１０日乃至４ケ月の間の抗磁力とその最大抗磁
力との差が最大抗磁力に対し１０％以内の範囲に上昇し
、その後常温で放置しても殆んど抗磁力が変化しないか
、変化があっても著しく少なく、抗磁力の経時安定性に
優れた磁気記録媒体を得ることができることを見出した
。The present inventor has discovered that when such a magnetic recording medium is subjected to a heat treatment at 40 to 150°C for about 10 days to 30 minutes at an appropriate time immediately after manufacturing or within about 10 days after manufacturing, the manufacturing process of the recording medium can be improved. After 10 days to 4 months, the difference between the coercive force and the maximum coercive force increases to within 10% of the maximum coercive force, and after that, the coercive force hardly changes even if left at room temperature. It has been found that it is possible to obtain a magnetic recording medium in which the change in coercive force is extremely small and has excellent stability over time of coercive force.
加熱処理はロールに巻かれた状態で大空中で行えばよい
。The heat treatment may be performed in the open air while being wound into a roll.
又、本発明によシ上記の如く加熱処理を施こすと、抗磁
力の経時安定性が改良されると共に、磁気記録媒体の出
力及び重ね書き特性の温度上昇による劣化を防止できる
ことも本発明の特筆すべき効果である。Further, according to the present invention, when heat treatment is performed as described above, the stability of coercive force over time is improved, and deterioration of the output and overwriting characteristics of the magnetic recording medium due to temperature rise can be prevented. This is a noteworthy effect.
すなわち、上記の如き磁気記録媒体を加熱処理を施こす
ことなく例えば６０℃の温度において出力測定すると、
出力低下が室ｍ（約２３℃）時の２５チ以上になるのに
対し１本発明てより前記の如き加熱処理を施こすと６０
℃でも出力低下が２０％以内になることがわかった。That is, when the output of the magnetic recording medium as described above is measured at a temperature of, for example, 60°C without heat treatment,
The output decreases by more than 25 inches when room m (approximately 23 degrees Celsius) is used, but when the heat treatment as described above is performed using the present invention, the output decreases by 60 degrees.
It was found that the output decrease was within 20% even at ℃.
「重ね書き」とは、例えば１２５ ＫＨｚの記録波長で
記録した後に他の記録波長、例えば２５０ ＫＨ２の記
録波長で同一チャンネルに記録することを云う。"Overwriting" refers to recording at a recording wavelength of, for example, 125 KHz, and then recording at another recording wavelength, for example, at a recording wavelength of 250 KH2, on the same channel.
その際に１２５ ＫＨ２の記録波長の記録が児全には消
去されないで記録として残存することになるがその残存
する部分は２５０ ＫＨｚの記録に対１７ノイズ成分と
なる。重ね書きしたディスクの記録再生出力を測定した
ときに２５０ ＫＨｚの再生出力を５２５８ｋ。At this time, the recording at the recording wavelength of 125 KH2 is not completely erased and remains as a record, but the remaining portion has a noise component of 17 compared to the recording at 250 KHz. When measuring the recording and playback output of the overwritten disc, the playback output at 250 KHz was 5258K.
１２５ＫＨｚの残存部の再生出力を８１□５、とすると
Ｓ ／Ｓ か重ね書き特性として表わされこ１２
５ｋ ２５０に
の値が小さい方が重ね書き特性がよい。If the reproduction output of the remaining part of 125KHz is 81□5, it can be expressed as S /S or overwriting characteristics.12
The smaller the value of 5k250, the better the overwriting characteristics.
Ｃａ−置換Ｂａ−フェライト含有磁気記録媒体の重ね書
き特性の温度依存性を調べた結果、他の磁気記録媒体（
例えばｃｏ−ｒＦｅ２Ｏ３，メタル磁材による磁気記録
媒体）に比して温度依存性が大きく、測定時の温度上昇
に伴なって重ね書き特性が劣化することがわかった。As a result of investigating the temperature dependence of the overwriting characteristics of magnetic recording media containing Ca-substituted Ba-ferrite, we found that other magnetic recording media (
For example, it has been found that the temperature dependence is greater than that of cor-rFe2O3 (magnetic recording media made of metal magnetic materials), and that the overwriting characteristics deteriorate as the temperature rises during measurement.
上記の如き磁気記録媒体を例えば６０℃に保つと、重ね
書き特性が室温（約２３℃）時を１００％とした時１２
５１以上に劣化する（例えば第２図サンプルＡ）が、本
発明により加熱処理を施こすと、重ね書き特性の劣化を
１２５多以下にすることができる。When a magnetic recording medium such as the one described above is kept at a temperature of, for example, 60°C, the overwriting characteristic is 12
However, by applying heat treatment according to the present invention, the deterioration of the overwriting characteristic can be reduced to 125 or less (for example, sample A in FIG. 2).
（例えば第２図サンプルＢ、Ｃ，Ｄ）
本発明においてはまた、帯電防止、転写防止、ワウフラ
ッタ−の防止、磁気記録媒体の強度向上。(For example, Samples B, C, and D in FIG. 2) The present invention also provides antistatic, antitransfer, prevention of wow and flutter, and improvement in the strength of magnetic recording media.
バック面のマット化等の目的で、非磁性支持体の磁性層
を設けた側の反対の面（バック面）がいわゆるバラフコ
−） （ｂａｃｋｃｏａｔ ）されていてもよい・この
バック層は組成としては前記の欄滑剤、研磨剤、帯電防
止剤などの少なくとも１種の添加剤、および場合によっ
てはこれらを均一に分散させるために分散剤を前記の結
合剤、塗布溶媒と混線、分散した塗布液を上記の支持体
のバック面上に塗布、乾燥して設けたものである。前記
の磁性層およびバンク層は支持体上にどちらかが先て設
けられても良い。For the purpose of matting the back surface, etc., the surface (back surface) opposite to the side on which the magnetic layer of the nonmagnetic support is provided may be coated with a so-called backcoat.The composition of this back layer is At least one additive such as a lubricant, an abrasive, an antistatic agent, etc., and in some cases, a dispersant is mixed with the binder and coating solvent to uniformly disperse these additives, and the dispersed coating liquid is mixed with the above-mentioned binder and coating solvent. It is provided by coating and drying on the back surface of the above support. Either the magnetic layer or the bank layer may be provided on the support first.
通常使用される好ましい添加剤はカーボンブラック、グ
ラファイト、タルク、ｃｒ２０３． ＴｌＯ２゜ＣａＣ
０ａｌＦｅＯｘ （ｘは１．３３〜１．５０ ）、シリ
コーンオイルなどであり、これらの単独もしくは２者以
上を混合してもよい。結合剤は前記のうち熱硬化性樹脂
又は反応型樹脂が好ましい。Preferred additives commonly used are carbon black, graphite, talc, CR203. TlO2゜CaC
0alFeOx (x is 1.33 to 1.50), silicone oil, etc., and these may be used alone or in combination of two or more. Among the binders mentioned above, thermosetting resins or reactive resins are preferred.
バック層全固形分に対して無機化合物の添加剤の場合は
約２０ル８５
機化合物の添加剤の場合は約０．１〜３０ｗｔ％、好ま
しくは０．２〜２Ｃ）ｗｔ％の混合比で設けられる。又
、乾燥厚味は約５．０μｍ以下の範囲で磁気記録媒体の
全厚、用途、形状、目的等に応じて任意に選択すること
ができる。In the case of inorganic compound additives, the mixing ratio is about 20 l85, and in the case of organic compound additives, about 0.1 to 30 wt%, preferably 0.2 to 2 C) wt%, based on the total solid content of the back layer. provided. Further, the dry thickness can be arbitrarily selected within a range of about 5.0 μm or less depending on the total thickness, use, shape, purpose, etc. of the magnetic recording medium.
次に本発明を実施例により更に具体的に説明する。尚実
施例中「部」は［重量部ｊを示すものである。Next, the present invention will be explained in more detail with reference to Examples. In the examples, "parts" indicate parts by weight.
実施例−１ Ｃｏ置換Ｂａ−フェライト（平均粒径０．０７μｍ。Example-1 Co-substituted Ba-ferrite (average particle size 0.07 μm.
平均厚み０． ０ ２ ５μｍ．抗磁力５５００θ）
３００部塩化ビニル−酢酸ビニル−無水マレ
イン酸共重合体（ＴＬｆ．今度４５０ ）
ｔｓ部部子チルエチルケトン
３６部トンエン
３６部上記組成で６０分混練しだ後
更に下記を加える。Average thickness 0. 0 2 5μm. Coercive force 5500θ)
300 parts vinyl chloride-vinyl acetate-maleic anhydride copolymer (TLf. 450 this time)
ts part ethyl ethyl ketone
36th part Tongen
36 parts After kneading the above composition for 60 minutes, the following was further added.
ダラファイト粉末 ６ 部ステア
リン酸アミル ４ ｔｔレシチ
ン １．２〃酸化クロム
（Ｃｒ２０３）５ “
ポリエステルポリオール ５０〃メチルエ
チルケトン ２６４ 〃トルエン
２６４〃これらが均一になる
ようにサンドグラインダーで１０時間混合分散を行い、
更に
ポリインシアネート ３０部を加え
再びサンドグラインダーで混合分散させ硬化性の磁性塗
料とした。これについて放電処理した７５μｍのポリエ
チレンテレフタレートフィルムの両面に乾燥厚みが夫々
３μｍとなるようにグラビアロールを用いて塗布し乾燥
しカレンダー処理をした。得られた磁気記録媒体をＡ、
Ｂ、Ｃ。Daraphite powder 6 parts Amyl stearate 4 parts tt lecithin 1.2 Chromium oxide (Cr203) 5" Polyester polyol 50 Methyl ethyl ketone 264 Toluene
264〃Mix and disperse with a sand grinder for 10 hours to make them uniform.
Further, 30 parts of polyincyanate was added and again mixed and dispersed using a sand grinder to obtain a curable magnetic coating. This was applied to both sides of a 75 μm polyethylene terephthalate film subjected to discharge treatment using a gravure roll so that the dry thickness was 3 μm on each side, dried, and calendered. The obtained magnetic recording medium is A,
B.C.
ＤＫ４分割し、カレンダー処理後１０日間夫々異った環
境条件下装置き、その後は２３℃６０チの同一環境条件
下に行いて、その後の夫々の抗磁力の変化を４８ケ月間
にわたり調べた。その結果を第１表及び第１図に示す（
Ａは比較例、Ｂ、Ｃ，Ｄは実施例）。DK was divided into 4 parts, and after calendering, they were each placed under different environmental conditions for 10 days, and then under the same environmental conditions at 23°C and 60°C, and the subsequent changes in coercive force of each were examined over a period of 48 months. The results are shown in Table 1 and Figure 1 (
A is a comparative example, B, C, and D are examples).
実施例−２
実施例−１において、ＣＯ置換Ｂａ−フェライトの抗磁
力を１００（ｔｏｅとした他は実施例−１と同様に処理
し、得られた磁気記録媒体をＥＦＧＨに分割し、実施例
−１と同様に抗磁力変化を調べた。Example-2 In Example-1, the coercive force of the CO-substituted Ba-ferrite was changed to 100 (toe), but the same process as in Example-1 was carried out, and the obtained magnetic recording medium was divided into EFGH. Coercive force changes were investigated in the same manner as in -1.
その結果も第１表及び第１図に示す（Ｅは比較例、１’
、Ｇ、Ｈは実施例）。The results are also shown in Table 1 and Figure 1 (E is a comparative example, 1'
, G, and H are examples).
第１表及び第１図かられかるように１３．Ｃ，ＤはＡに
比して又Ｆ’、Ｇ、ＨＨＥに比して抗磁力の経時安定性
が大巾に増していることがわかる。As can be seen from Table 1 and Figure 1, 13. It can be seen that the stability of the coercive force over time in C and D is significantly increased compared to A, and compared to F', G, and HHE.
Ａ−Ｄサンプルについて、カレンダー処理後のサンプル
を３．５インチフロッピーディスクに打抜き室温（２３
℃）及び６０℃において重ね書き及び再生出力をｔｌｉ
定した。測定ドライブは３．５インチ２、□ＭＢ ５Ｏ
ＮＹ製を使用し２３℃での測定値を１００チとしたとき
の６０℃での重ね書き及び再生出力をｔ、 ２図、第３
図に示した。６０℃においてＢ、Ｃ。For A-D samples, the samples after calendering were punched out onto 3.5-inch floppy disks and stored at room temperature (23
℃) and 60℃ for overwriting and playback output.
Established. Measurement drive is 3.5 inch 2, □MB 5O
The overwriting and playback output at 60°C is t, when the measured value at 23°C is 100 cm using a New York product. Figure 2, Figure 3
Shown in the figure. B, C at 60°C.
ＤがＡに比して重ね書き及び再生出力が大巾に改善され
ていることがわかる。It can be seen that D has greatly improved overwriting and playback output compared to A.
第１図はＢａ−フェライト系強磁性体を用いた磁気記録
媒体の抗磁力のカレンダー処理後の経時変化を示すグラ
フ、第２融及び第３図はそれぞれ重ね書き特性及び再生
出力特性の温度による変化を示すグラフである。
（はｐＨ６名）
第２図
表１１ ラえビラＬη１
第 ３ 図
唄１１実１浅Figure 1 is a graph showing the change over time in the coercive force of a magnetic recording medium using Ba-ferrite ferromagnetic material after calendering. It is a graph showing changes. (pH 6 people) 2nd diagram 11 Raebira Lη1 3rd diagram 11 fruit 1 shallow
Claims (2)
有する強磁性体粉末を結合剤中に分散させた磁性層を非
磁性支持体上に設けてなる磁気記録媒体において、該磁
気記録媒体の抗磁力が加熱処理によって強制的に変化さ
せられ、加熱処理終了後から磁気記録媒体製造後６ケ月
迄の各時点における抗磁力とその後の最大抗磁力との差
が最大抗磁力に対し１０％以内になるようにしたことを
特徴とする磁気記録媒体。(1) A magnetic recording medium in which a magnetic layer in which ferromagnetic powder is dispersed in a binder in a hexagonal flat plate shape and has an axis of easy magnetization perpendicular to the flat plate surface is provided on a nonmagnetic support. The coercive force of the recording medium is forcibly changed by heat treatment, and the difference between the coercive force at each point in time from the end of the heat treatment to 6 months after manufacturing the magnetic recording medium and the subsequent maximum coercive force is the maximum coercive force. A magnetic recording medium characterized in that the magnetic recording medium is within 10%.
分〜３ケ月間加熱することにより行う特許請求の範囲第
（１）項に記載の磁気記録媒体。(2) Heat treatment heats the magnetic recording medium to 40°C to 150°C.
The magnetic recording medium according to claim 1, which is heated for a period of minutes to three months.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61201754A JPH0677310B2 (en) | 1986-08-29 | 1986-08-29 | Magnetic recording medium |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP61201754A JPH0677310B2 (en) | 1986-08-29 | 1986-08-29 | Magnetic recording medium |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS6358620A true JPS6358620A (en) | 1988-03-14 |
| JPH0677310B2 JPH0677310B2 (en) | 1994-09-28 |
Family
ID=16446381
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP61201754A Expired - Lifetime JPH0677310B2 (en) | 1986-08-29 | 1986-08-29 | Magnetic recording medium |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0677310B2 (en) |
Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49120607A (en) * | 1973-03-20 | 1974-11-18 | ||
| JPS5186796A (en) * | 1974-12-18 | 1976-07-29 | Basf Ag | |
| JPS6070516A (en) * | 1983-09-28 | 1985-04-22 | Toshiba Corp | Magnetic recording medium |
| JPS61133029A (en) * | 1984-12-03 | 1986-06-20 | Nec Corp | Production of magnetic disk medium |
| JPS63273210A (en) * | 1987-05-01 | 1988-11-10 | Dowa Mining Co Ltd | Magnetic recording medium |
-
1986
- 1986-08-29 JP JP61201754A patent/JPH0677310B2/en not_active Expired - Lifetime
Patent Citations (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS49120607A (en) * | 1973-03-20 | 1974-11-18 | ||
| JPS5186796A (en) * | 1974-12-18 | 1976-07-29 | Basf Ag | |
| JPS6070516A (en) * | 1983-09-28 | 1985-04-22 | Toshiba Corp | Magnetic recording medium |
| JPS61133029A (en) * | 1984-12-03 | 1986-06-20 | Nec Corp | Production of magnetic disk medium |
| JPS63273210A (en) * | 1987-05-01 | 1988-11-10 | Dowa Mining Co Ltd | Magnetic recording medium |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH0677310B2 (en) | 1994-09-28 |
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| Publication | Publication Date | Title |
|---|---|---|
| JPS58100B2 (en) | Jikiki Rokutai | |
| US4666770A (en) | Magnetic recording medium | |
| US4911997A (en) | Magnetic recording medium | |
| US4572867A (en) | Magnetic recording medium | |
| JPS621114A (en) | Magnetic recording medium | |
| JPH043310A (en) | Magnetic recording medium | |
| JPH02110826A (en) | Magnetic disk | |
| JPS6358620A (en) | Magnetic recording medium | |
| JPS60147931A (en) | Manufacture of magnetic recording medium | |
| JP2700719B2 (en) | Magnetic recording medium and method of manufacturing the same | |
| JPH03116413A (en) | Magnetic recording medium | |
| JPS60111329A (en) | Magnetic recording medium | |
| JP2651749B2 (en) | Magnetic recording media | |
| JPH0481266B2 (en) | ||
| JPS6364625A (en) | Magnetic recording medium | |
| JPH04319523A (en) | Magnetic recording medium and production thereof | |
| JPH0630152B2 (en) | Method of manufacturing magnetic recording medium | |
| JPH02193314A (en) | Magnetic disk | |
| JPH02132639A (en) | Method and device for producing magnetic recording medium | |
| JPH03187014A (en) | Magnetic recording medium | |
| JPH0729152A (en) | Magnetic recording medium | |
| JPH04362513A (en) | Magnetic recording medium and production thereof | |
| JPH0481263B2 (en) | ||
| JPH0727630B2 (en) | Magnetic recording medium | |
| JPH039533B2 (en) |