US4256852A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Binder composition for magnetic recording tape
Assignee: Victor Company of Japan Ltd
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Filing: 1979-02-07
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Granted: 1981-03-17
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Expires: 1999-02-07
Abstract
Abstract A binder composition for magnetic recording tape which comprises polyisocyanate and a vinyl chloride-vinyl acetate copolymer non-reactive with the polyisocyanate, the copolymer being used in larger proportion. A resin or elastomer which is not reactive with the polyisocyanate may be added as a third component to impart flexibility or other desirable properties to the magnetic layer of tape.
Inventors
- 👤 Tunehide Naruse
- 👤 Ikuo Matsumoto
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 02:44
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7021; G11B5/7022
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
138 words
A binder composition for magnetic recording tape which ensures excellent mechanical strengths and causes little or no cupping or curling of the tape, said binder composition consisting essentially of (a) a major proportion of a vinyl chloride-vinyl acetate copolymer having a degree of polymerization of 300 to 500 and a vinyl acetate content of 3 wt.% to 15 wt.%; (b) a polyisocyanate in an amount of 5 to 80% by weight of the copolymer; and (c) a third component resin in an amount ranging from 0 up to 50 wt.% based on the total amount of said copolymer and said third component resin; said copolymer and said third component resin being non-reactive with the polyisocyanate whereby only the polyisocyanate takes part in a crosslinking reaction in which the isocyanate groups of the polyisocyanate react with moisture in air.
Claim 2
Dependent Claim
138 words
A binder composition for magnetic recording tape which ensures excellent mechanical strengths and causes little or no cupping or curling of the tape, said binder composition consisting essentially of (a) a major proportion of a vinyl chloride-vinyl acetate copolymer having a degree of polymerization of 300 to 500 and a vinyl acetate content of 3 wt.% to 15 wt.%; (b) a polyisocyanate in an amount of 5 to 80% by weight of the copolymer; and (c) a third component resin in an amount ranging from 0 up to 50 wt.% based on the total amount of said copolymer and said third component resin; said copolymer and said third component resin being non-reactive with the polyisocyanate whereby only the polyisocyanate takes part in a crosslinking reaction in which the isocyanate groups of the polyisocyanate react with moisture in air.
Claim 3
Dependent Claim
51 words
A binder composition according to claim 1, wherein said polyisocyanate is a member selected from the group consisting of a reaction product of 3 moles of 2, 4-tolylenediisocyanate and 1 mole of 2, 4-tolylelenediisocyanate, 2, 6-tolylenediisocyanate, hexamethylenediisocyanate and a reaction product of 3 moles of hexamethylenediisocyanate and 1 mole of trimethylolpropane.
Claim 4
Dependent Claim
15 words
A binder composition according to claim 1, wherein said third component resin is nitrile rubber.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-03-16 | 1984-09-15 | 1985-03-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-03-16 | 1988-09-15 | 1989-03-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-03-16 | 1992-09-15 | 1993-03-17 | $7700.00 | Window Closed / Lapsed |