US3928159A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for forming protective film by ionic plating
Assignee: Fujifilm Holdings Corp
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Filing: 1974-09-04
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Granted: 1975-12-23
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Expires: 1994-09-04
Abstract
Abstract In a method for formation of a protective film on a magnetic recording substance by ionic plating comprising generating a glow discharge of nitrogen or an inert gas at a vacuum of from about 1 X 10 1 mmHg to 1 X 10 5 mmHg between a magnetic recording substance as a substrate and at least one metal selected from the group consisting of the Group IB, Group IIB, Group VIB, Group VIIB and Group VIIIB metals as the evaporative source, and applying a voltage to the substrate and the evaporative source so that the electric potential of the substrate is more negative than the electric potential of the evaporative source.
Inventors
- 👤 Eiichi Tadokoro
- 👤 Tatsuji Kitamoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 16:10
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/72; C; C23; C23C; C23C14/00; C23C14/22; C23C14/24; C23C14/32
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
95 words
A METHOD FOR FORMATION OF A PROTECTIVE LAYER ON A MAGNETIC RECORDING SUBSTANCE BY IONIC PLATING COMPRISING GENERATING A GLOW DISCHARGE OF NITROGEN GAS ORGAN INERT GAS AT A VACUUM OF ABOUT 1X10**-1 TO ABOUT 1X10**-5 MMHG BETWEEN A MAGNETIC RECORDING SUBSTANCE AS A SUBSTRATE AND AT LEAST ONE METAL SELECTED FROM THE GROUP CONSISTING OF GROUP IB, GROUP IIB, GROUP VIB, GROUP VIIB AND GROUP VIIIB METALS AS AN EVAPORATIVE OF SAID SUBSTRATE IS MORE NEGATIVE THAN THE ELECTRIC POTENTIAL OF SAID SUBSTRATE IS MORE NEGATIVE THAN THE ELECTRIC POTENTIAL OF SAID EVAPORATIVE SOURCE.
Claim 2
Independent Claim
95 words
A METHOD FOR FORMATION OF A PROTECTIVE LAYER ON A MAGNETIC RECORDING SUBSTANCE BY IONIC PLATING COMPRISING GENERATING A GLOW DISCHARGE OF NITROGEN GAS ORGAN INERT GAS AT A VACUUM OF ABOUT 1X10**-1 TO ABOUT 1X10**-5 MMHG BETWEEN A MAGNETIC RECORDING SUBSTANCE AS A SUBSTRATE AND AT LEAST ONE METAL SELECTED FROM THE GROUP CONSISTING OF GROUP IB, GROUP IIB, GROUP VIB, GROUP VIIB AND GROUP VIIIB METALS AS AN EVAPORATIVE OF SAID SUBSTRATE IS MORE NEGATIVE THAN THE ELECTRIC POTENTIAL OF SAID SUBSTRATE IS MORE NEGATIVE THAN THE ELECTRIC POTENTIAL OF SAID EVAPORATIVE SOURCE.
Claim 3
Dependent Claim
67 words
The method as claimed in claim 1, including cleaning the surface of the magnetic recording substance to be plated by ionic plating by carrying out the glow discharge in a nitrogen gas or an inert gas atmosphere having a pressure of about 1 X 10 1 mmHg to 1 X 10 3 mmHg for 10 to 20 minutes prior to the ionic plating of the protective film.
Claim 4
Dependent Claim
39 words
The method as claimed in claim 1, wherein said evaporative metal is at least one metal selected from the group consisting of Cu, Ag, Au, Zn, Cr, Mo, W, Mn, Tc, Re, Ru, Rh, Pd, Os, Ir, and Pt.
Claim 5
Dependent Claim
29 words
The method as claimed in claim 1, wherein the inert gas is at least one gas selected from the group consisting of helium, neon, argon, krypton, xenon and radon.
Claim 6
Dependent Claim
23 words
The method as claimed in claim 1, wherein the applied voltage is a direct current voltage of about 0.5 kV to 5 kV.
Claim 7
Dependent Claim
18 words
The method as claimed in claim 1, wherein the ionic plating is for about 5 to 180 seconds.
Claim 8
Dependent Claim
22 words
The method as claimed in claim 1, wherein the thickness of the protective film ranges from about 0.05 to 2 Mu .
References Cited (Backward Citations)
US3531322A
Cited
US3498837A
Cited
US3516860A
Cited
US3674554A
Cited
US3772174A
Cited
US3767369A
Cited
US3829372A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-12-22 | 1979-06-23 | 1979-12-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-12-22 | 1983-06-23 | 1983-12-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-12-22 | 1987-06-23 | 1987-12-23 | $7700.00 | Window Closed / Lapsed |