CA1057396A - Self-lubricating magnetic recording diskette - Google Patents
Self-lubricating magnetic recording disketteInfo
- Publication number
- CA1057396A CA1057396A CA235,565A CA235565A CA1057396A CA 1057396 A CA1057396 A CA 1057396A CA 235565 A CA235565 A CA 235565A CA 1057396 A CA1057396 A CA 1057396A
- Authority
- CA
- Canada
- Prior art keywords
- fabric
- weight
- parts
- lubricant
- disk
- 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
- 239000004744 fabric Substances 0.000 claims abstract description 37
- 229920000570 polyether Polymers 0.000 claims abstract description 16
- 239000004721 Polyphenylene oxide Substances 0.000 claims abstract description 15
- 125000000217 alkyl group Chemical group 0.000 claims abstract description 6
- 239000000314 lubricant Substances 0.000 claims description 10
- 239000002904 solvent Substances 0.000 claims description 8
- 238000001704 evaporation Methods 0.000 claims description 2
- BFKJFAAPBSQJPD-UHFFFAOYSA-N tetrafluoroethene Chemical compound FC(F)=C(F)F BFKJFAAPBSQJPD-UHFFFAOYSA-N 0.000 claims description 2
- 238000000034 method Methods 0.000 claims 3
- 239000000835 fiber Substances 0.000 description 7
- 229920000297 Rayon Polymers 0.000 description 3
- 239000000463 material Substances 0.000 description 3
- 239000002964 rayon Substances 0.000 description 3
- 239000004743 Polypropylene Substances 0.000 description 2
- 238000000576 coating method Methods 0.000 description 2
- 239000002245 particle Substances 0.000 description 2
- -1 polypropylene Polymers 0.000 description 2
- 229920001155 polypropylene Polymers 0.000 description 2
- 125000001436 propyl group Chemical group [H]C([*])([H])C([H])([H])C([H])([H])[H] 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- BZHJMEDXRYGGRV-UHFFFAOYSA-N Vinyl chloride Chemical compound ClC=C BZHJMEDXRYGGRV-UHFFFAOYSA-N 0.000 description 1
- 239000000853 adhesive Substances 0.000 description 1
- 230000001070 adhesive effect Effects 0.000 description 1
- 239000011230 binding agent Substances 0.000 description 1
- 238000009835 boiling Methods 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000011248 coating agent Substances 0.000 description 1
- 230000001427 coherent effect Effects 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 230000032798 delamination Effects 0.000 description 1
- 239000000539 dimer Substances 0.000 description 1
- 238000010410 dusting Methods 0.000 description 1
- 125000001495 ethyl group Chemical group [H]C([H])([H])C([H])([H])* 0.000 description 1
- 229920002313 fluoropolymer Polymers 0.000 description 1
- 238000005470 impregnation Methods 0.000 description 1
- 238000003780 insertion Methods 0.000 description 1
- 230000037431 insertion Effects 0.000 description 1
- 238000005461 lubrication Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 239000004033 plastic Substances 0.000 description 1
- 229920003023 plastic Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 238000000638 solvent extraction Methods 0.000 description 1
- 238000003860 storage Methods 0.000 description 1
- 230000003746 surface roughness Effects 0.000 description 1
- 229920002994 synthetic fiber Polymers 0.000 description 1
- 239000012209 synthetic fiber Substances 0.000 description 1
- 125000000391 vinyl group Chemical group [H]C([*])=C([H])[H] 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
Classifications
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B23/00—Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus ; Intermediate mediums; Apparatus or processes specially adapted for their manufacture
- G11B23/02—Containers; Storing means both adapted to cooperate with the recording or reproducing means
- G11B23/03—Containers for flat record carriers
- G11B23/033—Containers for flat record carriers for flexible discs
- G11B23/0332—Containers for flat record carriers for flexible discs for single discs, e.g. envelopes
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B23/00—Record carriers not specific to the method of recording or reproducing; Accessories, e.g. containers, specially adapted for co-operation with the recording or reproducing apparatus ; Intermediate mediums; Apparatus or processes specially adapted for their manufacture
- G11B23/50—Reconditioning of record carriers; Cleaning of record carriers ; Carrying-off electrostatic charges
- G11B23/505—Reconditioning of record carriers; Cleaning of record carriers ; Carrying-off electrostatic charges of disk carriers
-
- 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
- G11B5/71—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 lubricant
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2213/00—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2213/00—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions
- C10M2213/04—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions obtained from monomers containing carbon, hydrogen, halogen and oxygen
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2213/00—Organic macromolecular compounds containing halogen as ingredients in lubricant compositions
- C10M2213/06—Perfluoro polymers
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/14—Electric or magnetic purposes
- C10N2040/16—Dielectric; Insulating oil or insulators
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/14—Electric or magnetic purposes
- C10N2040/17—Electric or magnetic purposes for electric contacts
Abstract
ABSTRACT
A flexible magnetic recording disk is contained in an envelope having a wiping fabric which is impregnated with a highly fluorinated alkyl polyether which transfers to the disk as it rotates within the envelope to lubricate the interface between the rotating disk and a magnetic recording head.
A flexible magnetic recording disk is contained in an envelope having a wiping fabric which is impregnated with a highly fluorinated alkyl polyether which transfers to the disk as it rotates within the envelope to lubricate the interface between the rotating disk and a magnetic recording head.
Description
~05'7~
SELF-LUBRICATING MAGNETIC RECORDING DISKETTE
This invention concerns a magnetic recording medium of the type that is called the diskette which comprises a flexible magnetic recording disk contained in an envelope to which is attached a wiping fabric in facing relationship to the disk. An early form of the diskette is disclosed in U. S. patent No. 3,668,658.
Diskettes are widely used as storage media for digital data. Virtually error-free performance is expected.
The aforementioned patent No. 3,668,658 showed that error-free performance could be enhanced by continuously wipingthe disk with a porous, low-friction, anti-static dusting fabric. To prolong the life of the disk by minimizing wear as the disk moves ln contact with a magnetic recording head, the disk has been provided with various lubricants. Never-theless, there has been a continuing demand for longer disk life, some users insisting that the disk should withstand one million passes of continuous contact with the head along a single track without a signal dropout and even asking for four million error-free passes or more.
The present invention significantly advances the diskette art by greatly prolonging the useful life of the t disk. This is accomplished by applying to the wiping fabric a dilute solution of a highly fluorinated alkyl polyether having a viscosity index (ASTM D 2270) of about 10-130 and then evaporating the solvent. Particularly preferred are highly fluorinated ethyl polyethers having the repeated unit and propyl polyethers having the repeating unit ~ 30 CF3 105~ 6 such as -CF3-cF2-cF2-o~cF-cF2-o~cFH-cF3 - CF3 n and the dimer thereof:
~ _ ~ 1 3~ ~
~CF3 CF2 C 2 -CF-CF2-O~ t :i ~ _CF3 ~ In /2 where n is an integer providing a viscosity index (ASTM D 2270) of about 10-130.
The highly fluorinated alkyl polyether is prefer- ~ ~ -ably applied by drawing long lengths of the fabric continu-ously through a bath containing about 0.1 to 1.0 part of the polyether per 100 parts of a solvent such as CC12FCClF2.
A lesser proportion of the polyether in the solution tends to 15 result in insufficient deposit of the polyether on the fabric ~ -whereas higher proportions of the polyether are considered less economical. Adequate impregnation is achieved when the fabric is advanced at a rate such that the fabric is immersed for about 1 to 20 seconds. Normally, the solvent evaporates in air at ordinary room temperatures within one minute after the fabric is withdrawn from the bath. Desirably, the dried fabric contains 1-20 parts by weight of the polyether per 100 parts by weight of the fabric. Lesser amounts do not provide error-free performance for periods as long as do amounts within that range, whereas greater amounts are considered to be unnecessary and expensive and may produce an esthetically undesirable visual pattern on the disk.
The wiping fabric should be a nonwoven, porous, tissue-like material of synthetic fibers which are insoluble in solvents for fluorocarbon polymers. Preferably the fabric ~0S73~6 is made from two fibers, one of which is employed at a relatively low proportion and initially has a lower soften-ing point than the other and is partially fused durlng fabrication to act as an adhesive ~oining the higher-softening fibers into a coherent fabric of the type general-ly disclosed in U. S. patent No. 2,676,128. A preferred fabric consists of 80 parts by weight of rayon fibers and 20 parts by weight of polypropylene fibers which bond the rayon fibers together. The weight of the fabric may be 10-100 (preferably 20-45) grams per square meter. Fabric having a weight below that range may be unduly fragile whereas a heavler fabric would tend to be too thick to meet current industry specifications for the diskette.
The single figure of the drawing is & perspective vlew of a diskette, cut away to show details.
In the drawing, a magnetic recordlng disk 10 is positioned within a flexible, shape-retaining plastic envelope 12. A porous, nonwoven, tissue-like fabric 14 attached to the inner walls of the envelope is impregnated with highly fluorinated alkyl polyether lubricant (not shown).
In use, the disk 10 is rotatively driven at its central opening 16 while the envelope remains stationary, and a magnetic recording head (not shown) contacts the rotating disk through either of the identical oval apertures 18 in each of the side walls of the envelope. As the disk 10 rotates, it lightly contacts the fabric 14, and the poly-ether lubricant gradually transfers to the surface of the disk to provide continuous lubrication between the head and the disk.
lV~7~96 Exa ple A diskette as illustrated in the drawing was pre-pared using a nonwoven wiping fabric consisting of 80 parts by weight of rayon fibers of approximately 1.5 denier and 20 parts by weight of polypropylene fibers of approximately 1.5 denler which have been fused together to afford integrity to the fabric. The weight of the fabric was about 36 grams per square meter.
The fabric was immersed for 15 seconds into a solution of approximately one part by weight of a solute comprising a highly fluorinated propyl polyether (viz., "Krytox" 143AZ) in 100 parts by weight of the solvent CC12FCClF2 (viz., "Freon" 113). It ls believed that part of the solute was a telomer of F2C=CF2. The vlscosity lndex (ASTM D 2270) of the solute was 23, its density at 24C was 1.86 g/ml and its boiling point range at 0.8 mm Hg was 143-185C. Within 45 seconds after being withdrawn from the bath, the solvent had substantially evaporated in air at room temperature. Solvent extraction indicated the presence of 11 parts b~ weight of the solute Per 100 parts by weight of the fabric.
The treated fabric was cut to shape and attached to the envelope material at areas ad~acent the openings and edges and at intermediate areas by a single pass of a roll having knurled sections of about 3 mm in width which had been preheated to 175C. The envelope material was a film of a copolymer of about 90 parts by weight of vinyl chloride and 10 parts b~ weight of vinyl acetate containing about 10%
carbon particles and having a matte surface. The temperature of the knurl roll was sufficient to fuse the fabric to the lOS73~6 vinyl fllm without observable change in the overall porosity of the fabric. Attempts to remove the fabric resulted in its delamination at the fused areas.
The magnetic recording disk was of conventional construction, having a backing of biaxiall~-oriented poly-ethylene terephthalate film 0.08 mm in thickness and a 0.003 mm coating of acicular gamma-Fe203 particles in binder on each surface. The coatings were polished to a surface roughness not exceeding oOo8 micrometer. The envelope and fabric were folded and two edges were heat-sealed followed by insertion of the disk and sealing of the third ~dge to pro-vlde a permanent enclosure for the disk as shown in the t drawing.
This dlskette was tested by rotatln~ the disk ln contact with a magnetic recording head along a sin~le track continuously except for periodic tests for dropouts. A drop-out was not detected after two million passes, at which point the test was discontinued. An otherwise identical diskette except for omission of the lubricant showed a drop-out withln 160,000 passes.
SELF-LUBRICATING MAGNETIC RECORDING DISKETTE
This invention concerns a magnetic recording medium of the type that is called the diskette which comprises a flexible magnetic recording disk contained in an envelope to which is attached a wiping fabric in facing relationship to the disk. An early form of the diskette is disclosed in U. S. patent No. 3,668,658.
Diskettes are widely used as storage media for digital data. Virtually error-free performance is expected.
The aforementioned patent No. 3,668,658 showed that error-free performance could be enhanced by continuously wipingthe disk with a porous, low-friction, anti-static dusting fabric. To prolong the life of the disk by minimizing wear as the disk moves ln contact with a magnetic recording head, the disk has been provided with various lubricants. Never-theless, there has been a continuing demand for longer disk life, some users insisting that the disk should withstand one million passes of continuous contact with the head along a single track without a signal dropout and even asking for four million error-free passes or more.
The present invention significantly advances the diskette art by greatly prolonging the useful life of the t disk. This is accomplished by applying to the wiping fabric a dilute solution of a highly fluorinated alkyl polyether having a viscosity index (ASTM D 2270) of about 10-130 and then evaporating the solvent. Particularly preferred are highly fluorinated ethyl polyethers having the repeated unit and propyl polyethers having the repeating unit ~ 30 CF3 105~ 6 such as -CF3-cF2-cF2-o~cF-cF2-o~cFH-cF3 - CF3 n and the dimer thereof:
~ _ ~ 1 3~ ~
~CF3 CF2 C 2 -CF-CF2-O~ t :i ~ _CF3 ~ In /2 where n is an integer providing a viscosity index (ASTM D 2270) of about 10-130.
The highly fluorinated alkyl polyether is prefer- ~ ~ -ably applied by drawing long lengths of the fabric continu-ously through a bath containing about 0.1 to 1.0 part of the polyether per 100 parts of a solvent such as CC12FCClF2.
A lesser proportion of the polyether in the solution tends to 15 result in insufficient deposit of the polyether on the fabric ~ -whereas higher proportions of the polyether are considered less economical. Adequate impregnation is achieved when the fabric is advanced at a rate such that the fabric is immersed for about 1 to 20 seconds. Normally, the solvent evaporates in air at ordinary room temperatures within one minute after the fabric is withdrawn from the bath. Desirably, the dried fabric contains 1-20 parts by weight of the polyether per 100 parts by weight of the fabric. Lesser amounts do not provide error-free performance for periods as long as do amounts within that range, whereas greater amounts are considered to be unnecessary and expensive and may produce an esthetically undesirable visual pattern on the disk.
The wiping fabric should be a nonwoven, porous, tissue-like material of synthetic fibers which are insoluble in solvents for fluorocarbon polymers. Preferably the fabric ~0S73~6 is made from two fibers, one of which is employed at a relatively low proportion and initially has a lower soften-ing point than the other and is partially fused durlng fabrication to act as an adhesive ~oining the higher-softening fibers into a coherent fabric of the type general-ly disclosed in U. S. patent No. 2,676,128. A preferred fabric consists of 80 parts by weight of rayon fibers and 20 parts by weight of polypropylene fibers which bond the rayon fibers together. The weight of the fabric may be 10-100 (preferably 20-45) grams per square meter. Fabric having a weight below that range may be unduly fragile whereas a heavler fabric would tend to be too thick to meet current industry specifications for the diskette.
The single figure of the drawing is & perspective vlew of a diskette, cut away to show details.
In the drawing, a magnetic recordlng disk 10 is positioned within a flexible, shape-retaining plastic envelope 12. A porous, nonwoven, tissue-like fabric 14 attached to the inner walls of the envelope is impregnated with highly fluorinated alkyl polyether lubricant (not shown).
In use, the disk 10 is rotatively driven at its central opening 16 while the envelope remains stationary, and a magnetic recording head (not shown) contacts the rotating disk through either of the identical oval apertures 18 in each of the side walls of the envelope. As the disk 10 rotates, it lightly contacts the fabric 14, and the poly-ether lubricant gradually transfers to the surface of the disk to provide continuous lubrication between the head and the disk.
lV~7~96 Exa ple A diskette as illustrated in the drawing was pre-pared using a nonwoven wiping fabric consisting of 80 parts by weight of rayon fibers of approximately 1.5 denier and 20 parts by weight of polypropylene fibers of approximately 1.5 denler which have been fused together to afford integrity to the fabric. The weight of the fabric was about 36 grams per square meter.
The fabric was immersed for 15 seconds into a solution of approximately one part by weight of a solute comprising a highly fluorinated propyl polyether (viz., "Krytox" 143AZ) in 100 parts by weight of the solvent CC12FCClF2 (viz., "Freon" 113). It ls believed that part of the solute was a telomer of F2C=CF2. The vlscosity lndex (ASTM D 2270) of the solute was 23, its density at 24C was 1.86 g/ml and its boiling point range at 0.8 mm Hg was 143-185C. Within 45 seconds after being withdrawn from the bath, the solvent had substantially evaporated in air at room temperature. Solvent extraction indicated the presence of 11 parts b~ weight of the solute Per 100 parts by weight of the fabric.
The treated fabric was cut to shape and attached to the envelope material at areas ad~acent the openings and edges and at intermediate areas by a single pass of a roll having knurled sections of about 3 mm in width which had been preheated to 175C. The envelope material was a film of a copolymer of about 90 parts by weight of vinyl chloride and 10 parts b~ weight of vinyl acetate containing about 10%
carbon particles and having a matte surface. The temperature of the knurl roll was sufficient to fuse the fabric to the lOS73~6 vinyl fllm without observable change in the overall porosity of the fabric. Attempts to remove the fabric resulted in its delamination at the fused areas.
The magnetic recording disk was of conventional construction, having a backing of biaxiall~-oriented poly-ethylene terephthalate film 0.08 mm in thickness and a 0.003 mm coating of acicular gamma-Fe203 particles in binder on each surface. The coatings were polished to a surface roughness not exceeding oOo8 micrometer. The envelope and fabric were folded and two edges were heat-sealed followed by insertion of the disk and sealing of the third ~dge to pro-vlde a permanent enclosure for the disk as shown in the t drawing.
This dlskette was tested by rotatln~ the disk ln contact with a magnetic recording head along a sin~le track continuously except for periodic tests for dropouts. A drop-out was not detected after two million passes, at which point the test was discontinued. An otherwise identical diskette except for omission of the lubricant showed a drop-out withln 160,000 passes.
Claims (5)
1. Method of extending the useful life of a flexible magnetic recording disk which is contained in an envelope to which a wiping fabric is attached comprising the steps of:
(1) applying to the wiping fabric a dilute solution of a lubricant primarily comprising a highly fluorinated alkyl polyether having a viscosity index of about 10-130, and (2) evaporating the solvent to provide about 1-20 parts by weight of the lubricant per 100 parts by weight of the fabric.
(1) applying to the wiping fabric a dilute solution of a lubricant primarily comprising a highly fluorinated alkyl polyether having a viscosity index of about 10-130, and (2) evaporating the solvent to provide about 1-20 parts by weight of the lubricant per 100 parts by weight of the fabric.
2. Method as defined in claim 1 wherein the fabric is immersed in the solution for about 1-20 seconds and then dried by exposure to air at ordinary room temperature.
3. Method as defined in claim 2 wherein the solution contains about 0.1 to one part by weight of the lubricant per 100 parts by weight of the solvent.
4. A diskette comprising an envelope containing a flexible magnetic recording disk and a tissue-like wiping fabric attached to the envelope in facing relationship to the disk, characterized by the fact that the fabric is impregnated with a lubricant primarily comprising a highly fluorinated alkyl polyether having a viscosity index of about 10-130, there being about 1-20 parts by weight of the polyether per 100 parts by weight of the fabric.
5. A diskette according to claim 4 further characterized by the fact that said polyether comprises a major proportion of the lubricant and a telemer of F2C=CF2 comprises a minor proportion of the lubricant.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US51247474A | 1974-10-07 | 1974-10-07 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1057396A true CA1057396A (en) | 1979-06-26 |
Family
ID=24039257
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA235,565A Expired CA1057396A (en) | 1974-10-07 | 1975-09-16 | Self-lubricating magnetic recording diskette |
Country Status (6)
| Country | Link |
|---|---|
| JP (1) | JPS552666B2 (en) |
| CA (1) | CA1057396A (en) |
| DE (1) | DE2545091B2 (en) |
| FR (1) | FR2287744A1 (en) |
| GB (1) | GB1508227A (en) |
| IT (1) | IT1047715B (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4417291A (en) * | 1979-12-26 | 1983-11-22 | Minnesota Mining And Manufacturing Company | Recording diskette having flocked-fiber wiping fabric |
Families Citing this family (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS529403A (en) * | 1975-07-14 | 1977-01-25 | Yoshiro Nakamatsu | Bulge recording disc used for electronic computer and so on |
| JPS6037735Y2 (en) * | 1976-10-27 | 1985-11-11 | 日立マクセル株式会社 | magnetic disk cartridge |
| JPS5361320A (en) * | 1976-11-12 | 1978-06-01 | Hitachi Maxell | Method of making magnetic disc cartridge |
| JPS53110513A (en) * | 1977-03-08 | 1978-09-27 | Fuji Photo Film Co Ltd | Disc jacket for magnetic recording |
| JPS5459124A (en) * | 1977-10-19 | 1979-05-12 | Hitachi Ltd | Magnetic tape cleaning apparatus |
| JPS6241423Y2 (en) * | 1978-04-03 | 1987-10-23 | ||
| AU558371B2 (en) * | 1981-05-30 | 1987-01-29 | Sony Corporation | Flexible magnetic disc cassette |
| US4609956A (en) * | 1982-09-02 | 1986-09-02 | Fuji Electrochemical Co., Ltd. | Magnetic drum cassette with magnetic drum having voice information recorded thereon |
| JPH0632193B2 (en) * | 1985-01-07 | 1994-04-27 | 富士写真フイルム株式会社 | Magnetic disk cartridge |
| KR900002242A (en) * | 1988-07-14 | 1990-02-28 | 나가이 아쯔시 | Magnetic disk cartridge |
| GB2268447B (en) * | 1992-07-02 | 1996-07-10 | Secr Defence | Packaging materials |
| JPH0636500A (en) * | 1992-07-17 | 1994-02-10 | Kao Corp | Magnetic disk jacket |
| JPH06195922A (en) * | 1992-12-25 | 1994-07-15 | Kao Corp | Treatment and apparatus for treatment of liner material for magnetic recordin medium |
-
1975
- 1975-09-16 CA CA235,565A patent/CA1057396A/en not_active Expired
- 1975-10-06 IT IT51668/75A patent/IT1047715B/en active
- 1975-10-06 FR FR7530487A patent/FR2287744A1/en active Granted
- 1975-10-06 JP JP11985375A patent/JPS552666B2/ja not_active Expired
- 1975-10-06 GB GB40826/75A patent/GB1508227A/en not_active Expired
- 1975-10-06 DE DE19752545091 patent/DE2545091B2/en not_active Ceased
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US4417291A (en) * | 1979-12-26 | 1983-11-22 | Minnesota Mining And Manufacturing Company | Recording diskette having flocked-fiber wiping fabric |
Also Published As
| Publication number | Publication date |
|---|---|
| FR2287744A1 (en) | 1976-05-07 |
| DE2545091B2 (en) | 1977-10-20 |
| DE2545091A1 (en) | 1976-04-08 |
| GB1508227A (en) | 1978-04-19 |
| JPS5166818A (en) | 1976-06-09 |
| IT1047715B (en) | 1980-10-20 |
| JPS552666B2 (en) | 1980-01-21 |
| FR2287744B1 (en) | 1980-06-27 |
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