EP0343576A2
Expired / Lapsed
EP
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Binders for magnetic recording media and magnetic recording media
Assignee: Takeda Pharmaceutical Co Ltd
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Filing: 1989-05-23
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Granted: —
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Expires: 2009-05-23
Abstract
Abstract The sulfobetaine-containing resin has much improved affinity for magnetic powders. Therefore, by using the same as a binder, it becomes possible to attain good dispersion of magnetic powders superfine in particle size and/or large in amount of magnetization. The binder can be used advantageously in the manufacture of magnetic recording media, such as magnetic tapes and magnetic disks.
Inventors
- 👤 Hiroyuki Shiraki
- 👤 Katsuhiro Hirata
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-23 05:47
CPC Classifications
G; G11; G11B; G11B5/00; G11B5/62; G11B5/68; G11B5/70; G11B5/702; G11B5/7023; C; C08; C08K; C08K5/00; C08K5/36; G11B5/7021; Y; Y10; Y10S; Y10S428/00; Y10S428/90; Y10T; Y10T428/00; Y10T428/26; Y10T428/263; Y10T428/264; Y10T428/265; Y10T428/31504; Y10T428/31551; Y10T428/31609
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
11 words
A binder for magnetic recording media which comprises a sulfobetaine-containing resin.
Claim 2
Dependent Claim
11 words
A binder for magnetic recording media which comprises a sulfobetaine-containing resin.
Claim 3
Dependent Claim
25 words
The binder for magnetic recording media claimed in claim 1, wherein the sulfobetaine content in the resin amounts to about 1 to 1,000 equivalents/10⁶ g.
Claim 4
Dependent Claim
23 words
The binder for magnetic recording media claimed in claim 1, wherein the sulfobetaine-containing resin is a urethane resin or a vinyl chloride copolymer.
Claim 5
Dependent Claim
40 words
The binder for magnetic recording media claimed in claim 3, wherein the urethane resin is one obtained by the reaction of a polyisocyanate with a polyhydroxy compound, a part of the polyhydroxy compound being replaced with a sulfobetaine-containing polyhydroxy compound.
Claim 6
Dependent Claim
64 words
The binder for magnetic recording media claimed in claim 4, wherein the sulfobetaine-containing polyhydroxy compound is a reaction product from a tertiary amine having two or more hydroxy groups and a sultone of the general formula wherein - R - is a straight or branched alkylene group having a carbon number of 1 to 20 and n is an integer of 2 to 20.
Claim 7
Dependent Claim
27 words
The binder for magnetic recording media claimed in claim 3, wherein the vinyl chloride copolymer is a copolymer of vinyl chloride and a sulfobetaine-containing monomer copolymerizable therewith.
Claim 8
Dependent Claim
59 words
The binder for magnetic recording media claimed in claim 6, wherein the sulfobetaine-containing monomer is a reaction product from a tertiary amino-containing vinyl monomer and a sultone of the general formula wherein - R - is a straight or branched alkylene group having a carbon number of 1 to 20 and n is an integer of 2 to 20.
Claim 9
Dependent Claim
47 words
The binder for magnetic recording media claimed in claim 1, wherein the sulfobetaine-containing resin is used in a combination of a thermoplastic resin having a softening point not lower than 150°C, an average molecular weight of 10,000 to 200,000 and polymerization degree of about 200 to 2,000.
Claim 10
Dependent Claim
21 words
The resin for magnetic recording media claimed in claim 8, wherein the thermoplastic resin is a vinyl chloride-vinyl acetate-vinyl alcohol copolymer.
Claim 11
Dependent Claim
26 words
The binder for magnetic recording media claimed in claim 1, wherein the sulfobetaine-containing resin is used in a combination of a polyisocyanate as a curing agent.
Claim 12
Dependent Claim
22 words
A magnetic recording medium which has a magnetic layer bound with a binder for magnetic recording media which comprises a sulfobetaine-containing resin.
Claim 13
Dependent Claim
22 words
A magnetic recording medium which has a magnetic layer bound with a binder for magnetic recording media which comprises a sulfobetaine-containing resin.
Claim 14
Dependent Claim
23 words
The magnetic recording medium claimed in claim 11, wherein the sulfobetaine content in the resin amounts to about 1 to 1,000 equivalents/10⁶ g.
Claim 15
Dependent Claim
21 words
The magnetic recording medium claimed in claim 11, wherein the sulfobetaine-containing resin is a urethane resin or a vinyl chloride copolymer.
Claim 16
Dependent Claim
39 words
The magnetic recording medium claimed in claim 11, which is prepared by coating a nonmagnetic support with a binder comprising a sulfobetaine-containing resin in an amount such that the film thickness after drying is about 0.1 to 50 µm.
References Cited (Backward Citations)
No citation records indexed.
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