GB1457258A - Magnetic recording media - Google Patents
Magnetic recording mediaInfo
- Publication number
- GB1457258A GB1457258A GB376373A GB376373A GB1457258A GB 1457258 A GB1457258 A GB 1457258A GB 376373 A GB376373 A GB 376373A GB 376373 A GB376373 A GB 376373A GB 1457258 A GB1457258 A GB 1457258A
- Authority
- GB
- United Kingdom
- Prior art keywords
- layer
- magnetisable
- magnetisable material
- coercivity
- chromium
- 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
Links
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
- G11B5/716—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 two or more magnetic layers
Abstract
1457258 Magnetic recording media EMI Ltd 14 Jan 1974 [25 Jan 1973] 3763/73 Heading B2E A magnetic recording medium comprises a support having first and second overlying layers of magnetisable material, the layers being separated by a barrier region of non- magnetisable material, the coercivity of the magnetisable material of the layer closer to the support being less than that of the magnetisable material of the outer layer. The barrier layer may be about 4Á thick or less. The layer nearer to the support may have a coercivity of 200 to 350 Oe while the outer magnetic layer may have a coercivity of 350 to 2000 Oe or chromium dioxide. In an exemplified tape a substrate web of polyethylene glycol terephthalate or other plastics material has a layer comprising particles of, for example, a magnetisable metal or metal alloy powder, chromium dioxide, cobalt doped iron oxide, magnetite, γ-ferric oxide, an overlying layer of non-magnetisable material and a further magnetisable layer which may contain the magnetisable material specified in the first magnetic layer or may be an evaporated metal film, formed for example from a mixture of cobalt and chromium, the chromium constituting 1-20% by weight. The intermediate layer may have a thickness of about 4Á and comprise α-ferric oxide in a suitable binder. The recording medium may be a tape, disc, drum or card.
Priority Applications (5)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB376373A GB1457258A (en) | 1973-01-25 | 1973-01-25 | Magnetic recording media |
| DE19742403401 DE2403401A1 (en) | 1973-01-25 | 1974-01-22 | MAGNETIZABLE RECORDING MEDIUM |
| FR7402193A FR2215667A1 (en) | 1973-01-25 | 1974-01-23 | |
| NL7400949A NL7400949A (en) | 1973-01-25 | 1974-01-23 | |
| JP49010589A JPS49111605A (en) | 1973-01-25 | 1974-01-24 |
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB376473 | 1973-01-25 | ||
| GB376373A GB1457258A (en) | 1973-01-25 | 1973-01-25 | Magnetic recording media |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1457258A true GB1457258A (en) | 1976-12-01 |
Family
ID=26238573
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB376373A Expired GB1457258A (en) | 1973-01-25 | 1973-01-25 | Magnetic recording media |
Country Status (5)
| Country | Link |
|---|---|
| JP (1) | JPS49111605A (en) |
| DE (1) | DE2403401A1 (en) |
| FR (1) | FR2215667A1 (en) |
| GB (1) | GB1457258A (en) |
| NL (1) | NL7400949A (en) |
Families Citing this family (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4237189A (en) | 1973-10-31 | 1980-12-02 | Robert J. Deffeyes | Polymodal magnetic recording media process for making and verifying the same and compositions useful therein |
| JPS5891B2 (en) * | 1977-09-30 | 1983-01-05 | 俊一 岩崎 | magnetic recording medium |
| US4237506A (en) * | 1978-04-03 | 1980-12-02 | Graham Magnetics Inc. | Polymodal magnetic recording member |
| DE3212907C2 (en) * | 1981-04-06 | 1985-10-24 | Olympus Optical Co., Ltd., Tokio/Tokyo | Magnetic tape and process for its manufacture |
| US4731300A (en) * | 1985-03-07 | 1988-03-15 | Victor Company Of Japan, Ltd. | Perpendicular magnetic recording medium and manufacturing method thereof |
-
1973
- 1973-01-25 GB GB376373A patent/GB1457258A/en not_active Expired
-
1974
- 1974-01-22 DE DE19742403401 patent/DE2403401A1/en active Pending
- 1974-01-23 NL NL7400949A patent/NL7400949A/xx unknown
- 1974-01-23 FR FR7402193A patent/FR2215667A1/fr not_active Withdrawn
- 1974-01-24 JP JP49010589A patent/JPS49111605A/ja active Pending
Also Published As
| Publication number | Publication date |
|---|---|
| NL7400949A (en) | 1974-07-29 |
| FR2215667A1 (en) | 1974-08-23 |
| DE2403401A1 (en) | 1974-08-01 |
| JPS49111605A (en) | 1974-10-24 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed | ||
| PCNP | Patent ceased through non-payment of renewal fee |