Patent US4532172A successfully refreshed from Google Patents.
US4532172A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Leader or trailer tape
Assignee: Fujifilm Holdings Corp
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Filing: 1979-08-02
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Granted: 1985-07-30
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Expires: 1999-08-02
Abstract
Abstract The present invention relates to a leader or trailer tape to be connected with a magnetic tape, which comprises a support base and two coating layers containing solid powders provided on the surface side and back side of the support base, the surface roughness of the one coating layer on the surface side being finer than that of the other coating layer on the back side, the surface roughness of the former being about 0.05 to 2 microns and that of the latter being about 0.5 microns or more.
Inventors
- 👤 Masaaki Fujiyama
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 07:50
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/627; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31; Y10T428/31504; Y10T428/31786; Y10T428/31797; Y10T428/31855; Y10T428/31935
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
139 words
A magnetic recording tape comprising a leader or trailer segment and a magnetic recording layer segment, the magnetic recording layer segment comprising a magnetic recording layer provided on a substrate and the leader or trailer segment comprising a support member having a coating layer provided on each of the surface and back sides of the support and not having a magnetic recording layer provided thereon; each coating layer comprising a binder and a powder, said powder being selected from the group consisting of extenders and white pigments, the surface roughness of the coating layer on the surface side of the support being finer than that of the coating layer on the back side of the support, the surface roughness of the former being 0.05 to 2 microns and the surface roughness of the latter being at least 0.5 micron.
Claim 2
Dependent Claim
139 words
A magnetic recording tape comprising a leader or trailer segment and a magnetic recording layer segment, the magnetic recording layer segment comprising a magnetic recording layer provided on a substrate and the leader or trailer segment comprising a support member having a coating layer provided on each of the surface and back sides of the support and not having a magnetic recording layer provided thereon; each coating layer comprising a binder and a powder, said powder being selected from the group consisting of extenders and white pigments, the surface roughness of the coating layer on the surface side of the support being finer than that of the coating layer on the back side of the support, the surface roughness of the former being 0.05 to 2 microns and the surface roughness of the latter being at least 0.5 micron.
Claim 3
Dependent Claim
32 words
The magnetic recording tape as claimed in claim 1, wherein said support member is of at least one material selected from the group consisting of polyesters, cellulose derivatives, vinyl resins and polyolefins.
Claim 4
Dependent Claim
23 words
The magnetic recording tape as claimed in claim 1 or 2, wherein said support member has a thickness of 4 to 200 microns.
Claim 5
Dependent Claim
21 words
The leader or trailer tape as claimed in claim 1, wherein said pigment has a Mohs' hardness of at most 4.
Claim 6
Dependent Claim
52 words
The magnetic recording tape as claimed in claim 1 or 4, wherein said extender is at least one material selected from the group consisting of calcium carbonate, magnesium silicate, barite, barium sulfate, clay, chalk, diatom earth, silica white, aluminum white, satin white, bentonite, calcium silicate, magnesium carbonate, calcium plumbate and aluminum silicate.
Claim 7
Dependent Claim
46 words
The magnetic recording tape as claimed in claim 1 or 4, wherein said white pigment is at least one material selected from the group consisting of zinc oxide, lithopone, zinc sulfide, white lead, lead sulfate, zirconium oxide, antimony white, tin oxide, titanium oxide and lead silicate.
Claim 8
Dependent Claim
53 words
The magnetic recording tape as claimed in claim 1 or 4, wherein said powder has a particle size of 0.02 to 10 microns in the coating layer on the surface side of said support member and of at least 0.5 micron in the coating layer on the back side of said support member.
Claim 9
Dependent Claim
49 words
The magnetic recording tape as claimed in claim 1, wherein the coating layer on the surface side of said support member has a thickness of at least 0.5 micron and the coating layer on the back side of said support member has a thickness of at least 2 microns.
Claim 10
Dependent Claim
32 words
The magnetic recording tape as claimed in claim 1, wherein the coating layer on the back side of said support member has a surface electric resistance of at most 10 10 Ω/sq.
Claim 11
Dependent Claim
31 words
The magnetic recording tape as claimed in claim 1, wherein the binder for the powder is at least one material selected from the group consisting of thermoplastic resins and thermosetting resins.
Claim 12
Dependent Claim
23 words
The magnetic recording tape as claimed in claim 1 or 10, wherein the pigment/binder ratio is in the range of 6/1 to 0.5/1.
Claim 13
Dependent Claim
23 words
The magnetic recording tape as claimed in claim 1, wherein an undercoated layer is provided between said support member and a coating layer.
Claim 14
Dependent Claim
34 words
The magnetic recording tape as claimed in claim 1 or 12, wherein the undercoated layer is of at least one material selected from the group consisting of amorphous linear polyesters and vinylidine chloride/acrylonitrile copolymers.
Claim 15
Dependent Claim
27 words
The magnetic recording tape as claimed in any one of claims 1, 12 and 13, wherein the undercoated layer has a thickness of 0.5 to 3 microns.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1988-07-29 | 1989-01-28 | 1989-07-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1992-07-29 | 1993-01-28 | 1993-07-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1996-07-29 | 1997-01-28 | 1997-07-30 | $7700.00 | Window Closed / Lapsed |