Patent US3033018A successfully refreshed from Google Patents.
Patent US4615930A successfully refreshed from Google Patents.
US4615930A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Magnetic recording media having an undercoat as islands
Assignee: Victor Company of Japan Ltd
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Filing: 1984-04-27
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Granted: 1986-10-07
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Expires: 2004-04-27
Abstract
Abstract A magnetic recording medium comprising a non-magnetic resin support, and a magnetic layer form on the support. A polyester or polyurethane resin undercoat is formed between the support and the magnetic layer in the form of islands which are isolated from one another.
Inventors
- 👤 Yukio Matsumoto
- 👤 Hirokazu Moriizumi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 05:41
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/73; G11B5/68; G11B5/70; G11B5/739; G11B5/73923; G11B5/73927; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10S428/91; Y10T; Y10T428/00; Y10T428/24; Y10T428/24355; Y10T428/24364; Y10T428/25; Y10T428/256; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31551; Y10T428/31565; Y10T428/31721; Y10T428/31725; Y10T428/31736; Y10T428/31786
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
105 words
A magnetic recording medium which comprises a non-magnetic resin support, islands of a polyester or polyurethane resin undercoat layer formed on one surface of the non-magnetic support, and a magnetic layer formed on the islands-bearing resin support wherein said resin support is a film made of a resin composition comprising a thermoplastic resin and 0.3 to 10 wt% of titanium oxide particles having an average size below 2.5 μm, and wherein the islands are formed by coating the resin undercoat with a thickness of 0.01 to 1.0 μm on the resin support and stretching the resin support to a draw ratio of 2 to 10.
Claim 2
Dependent Claim
105 words
A magnetic recording medium which comprises a non-magnetic resin support, islands of a polyester or polyurethane resin undercoat layer formed on one surface of the non-magnetic support, and a magnetic layer formed on the islands-bearing resin support wherein said resin support is a film made of a resin composition comprising a thermoplastic resin and 0.3 to 10 wt% of titanium oxide particles having an average size below 2.5 μm, and wherein the islands are formed by coating the resin undercoat with a thickness of 0.01 to 1.0 μm on the resin support and stretching the resin support to a draw ratio of 2 to 10.
Claim 3
Dependent Claim
29 words
The magnetic recording medium according to claim 1, wherein said resin support is a film of a thermoplastic resin selected from the group consisting of polyesters, polyamides and polyimides.
Claim 4
Dependent Claim
21 words
The magnetic recording medium according to claim 1, wherein the average size is in the range of 0.05 to 1.0 μm.
Claim 5
Dependent Claim
15 words
The magnetic recording medium according to claim 1, wherein said thermoplastic resin is a polyester.
Claim 6
Dependent Claim
17 words
The magnetic recording medium according to claim 1, wherein said undercoat is made of a water-soluble polyester.
Claim 7
Dependent Claim
18 words
The magnetic recording medium according to claim 1, wherein said undercoat layer is made of a water-soluble polyurethane.
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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) | 1989-10-06 | 1990-04-07 | 1990-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-06 | 1994-04-07 | 1994-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-06 | 1998-04-07 | 1998-10-07 | $7700.00 | Window Closed / Lapsed |