US3753252A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Disk pack assembly and method of making
Assignee: International Business Machines Corp
•
Filing: 1971-06-28
•
Granted: 1973-08-14
•
Expires: 1991-06-28
Abstract
Abstract A process for selectively affecting the magnetic properties in a magnetic particulate/resin material, such as an iron oxide-epoxy base coating as utilized on magnetic disks, disk pack assemblies and tapes, by creating an irreversible differential magnetic particle distribution in the surface of the material while maintaining the original surface topography, comprising the steps of exposing at least one preselected area of the surface for reaction with a reagent capable of converting the magnetic particulate material to a non-magnetic form, applying the reagent to the exposed areas, and removing the reagent from the preselected area of surface after a length of time sufficient to effect such conversion in the areas exposed, the reagent having the property of being substantially unreactive with the resin for the length of time of exposure.
Inventors
- 👤 A Tietze
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 23:29
CPC Classifications
G; G03; G03G; G03G5/00; G03G5/16; B; B82; B82Y; B82Y10/00; G11; G11B; G11B5/00; G11B5/48; G11B5/58; G11B5/596; G11B5/59633; G11B5/62; G11B5/68; G11B5/70; G11B5/716; G11B5/74; G11B5/743; G11B5/82; G11B5/84; G11B5/855
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
81 words
The method of claim 1 wherein the resist material comprises at least two photosensitive layers, the layer furthest from the surface being of finer resolution than the layer in contact with the surface, and including the step of exposing and developing the furthest layer in a preselected resist pattern to serve as a photomask for the layer in contact with the surface, then exposing and developing the layer in contact with the surface to expose the preselected area to the acid.
Claim 2
Dependent Claim
20 words
The method of claim 1 including the step of removing the resist material after the step of removing the acid.
Claim 3
Dependent Claim
29 words
The method of claim 1 wherein the preselected area is exposed to the acid by the step of directing the acid via a directing means to the preselected area.
Claim 4
Dependent Claim
14 words
The method of claim 4 wherein said directing means is of a nozzle configuration.
Claim 5
Dependent Claim
13 words
The method of claim 1 wherein said acid is of a gaseous form.
Claim 6
Dependent Claim
12 words
The method of claim 1 wherein the resin comprises an epoxy material.
Claim 7
Dependent Claim
12 words
The method of claim 7 wherein the resin comprises an epoxy-phenolic material.
Claim 8
Dependent Claim
12 words
The method of claim 1 wherein the resin comprises an epoxy-melamine material.
Claim 9
Dependent Claim
14 words
The method of claim 1 wherein said preselected area defines a positioning reference pattern.
Claim 10
Dependent Claim
21 words
The method of claim 1 wherein the substrate has a magnetic particulate material dispersed in a resin binder on both sides.
Claim 11
Dependent Claim
12 words
The method of claim 1 wherein the substrate is of disk configuration.
Claim 12
Dependent Claim
13 words
The method of claim 1 wherein the surface is of a disk configuration.
Claim 13
Dependent Claim
14 words
The method of claim 13 wherein the preselected areas define a positioning reference pattern.
Claim 14
Dependent Claim
14 words
The method of claim 13 wherein the preselected area define areas for recording information.
Claim 15
Dependent Claim
14 words
The method of claim 1 wherein the preselected areas define areas for recording information.
Claim 16
Dependent Claim
18 words
The method of claim 1 including the additional step of impregnating the preselected area with a lubricating medium.
Claim 17
Dependent Claim
34 words
An article of manufacture comprising a magnetic particulate material dispersed in a resin binder having an irreversible differential magnetic particle distribution defining areas of differing magnetic properties made by the process of claim 1.
Claim 18
Dependent Claim
12 words
The article of claim 18 wherein said article is in disk configuration.
Claim 19
Dependent Claim
41 words
A disk pack assembly comprising a plurality of disks upon a hub, at least one layer of at least one disk having an irreversible differential magnetic particle distribution defining areas of differing magnetic properties made by the method of claim 1.
Claim 20
Dependent Claim
19 words
The disk pack assembly of claim 20 wherein the areas of differing magnetic properties define a positioning reference pattern.
Claim 21
Dependent Claim
19 words
The disk pack assembly of claim 20 wherein the areas of differing magnetic properties defines areas for recording information.
References Cited (Backward Citations)
US2793135A
Cited
US3058844A
Cited
US3198657A
Cited
US3554798A
Cited
US3555557A
Cited
US3513021A
Cited
US3531322A
Cited
US3534344A
Cited
US3585141A
Cited
US3512930A
Cited
US3586630A
Cited
US3686031A
Cited
US3634252A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-08-13 | 1977-02-12 | 1977-08-14 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-08-13 | 1981-02-12 | 1981-08-14 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-08-13 | 1985-02-12 | 1985-08-14 | $7700.00 | Window Closed / Lapsed |