GB1490517A - Magnetisable storage media - Google Patents

Magnetisable storage media

Info

Publication number
GB1490517A
GB1490517A GB4876073A GB4876073A GB1490517A GB 1490517 A GB1490517 A GB 1490517A GB 4876073 A GB4876073 A GB 4876073A GB 4876073 A GB4876073 A GB 4876073A GB 1490517 A GB1490517 A GB 1490517A
Authority
GB
United Kingdom
Prior art keywords
magnetisable
orientation
medium
iron
oct
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
Application number
GB4876073A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
EMI Ltd
Original Assignee
EMI Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by EMI Ltd filed Critical EMI Ltd
Priority to GB4876073A priority Critical patent/GB1490517A/en
Publication of GB1490517A publication Critical patent/GB1490517A/en
Expired legal-status Critical Current

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

Landscapes

  • Paints Or Removers (AREA)

Abstract

1490517 Magnetisable storage media EMI Ltd 21 Oct 1974 [19 Oct 1973] 48760/73 Heading B2E [Also in Division B6] A method of making a magnetisable storage medium for a security document or device comprises dispersing magnetisable material particles e.g. acicular ferric oxide, chromium oxide, iron, cobalt, iron-cobalt alloy or nickel iron alloy, in a binder e.g. polyvinylchloride, polyvinylacetate, polyvinylacetals, polyester resins, polyamides, polyacrylic resins and rubber, and an additive, coating the mixture on a substrate e.g. paper, card or plastics tape and drying so that the medium has a selected particle proportion less than the maximum containable in the coating layer and less than 35% but with an orientation ratiohigher than at the maximum proportion. The term orientation ratio refers to the ratio of magnetic resonances in the plane of a layer of the medium, in the longitudinal and transverse directions relative to the orientation. The oriented particles may be in the form of a watermark as described or claimed in Speceifications 1331604 or 1486888.
GB4876073A 1974-10-21 1974-10-21 Magnetisable storage media Expired GB1490517A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
GB4876073A GB1490517A (en) 1974-10-21 1974-10-21 Magnetisable storage media

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB4876073A GB1490517A (en) 1974-10-21 1974-10-21 Magnetisable storage media

Publications (1)

Publication Number Publication Date
GB1490517A true GB1490517A (en) 1977-11-02

Family

ID=10449809

Family Applications (1)

Application Number Title Priority Date Filing Date
GB4876073A Expired GB1490517A (en) 1974-10-21 1974-10-21 Magnetisable storage media

Country Status (1)

Country Link
GB (1) GB1490517A (en)

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Legal Events

Date Code Title Description
PS Patent sealed
PCNP Patent ceased through non-payment of renewal fee