Claims
- 1. A magnetic recording medium comprised of a flexible support and at least one magnetic layer on said support comprising a water dispersible binder and magnetic pigments wherein the improvement comprises the magnetic layer includes a binder comprised of anionic polyurethane ionomers particles containing from 0.02 to 13% by weight of SO.sub.3.sup.- groups, being dispersed in water with dispersing agents, and said magnetic pigments and said polyurethane ionomer particles having a particle size of 20 nm to 400 nm, the volumetric ratio of magnetic pigment to polyurethane, based on the solids content, being in the range of 0.7:1 to 1.4:1.
- 2. A magnetic recording medium comprised of a flexible support and at least one magnetic layer on said support comprising a water dispersible binder and magnetic pigments wherein the improvement comprises
- the magnetic layer includes a binder comprised of anionic polyurethane ionomers particles containing from 0.02 to 13% by weight of SO.sub.3.sup.- groups, being dispersed in water with a dispersing agent selected from the group consisting of sodium polyphosphate, sodium hexametaphosphate, a salt of polyacrylic or polymethacrylic acid and a block polymer of polyethylene oxide and polypropylene oxide, and said magnetic pigments and said polyurethane ionomer particles having a particle size of 20 nm to 400 nm, the volumetric ratio of magnetic pigment to polyurethane, based on the solids content, being in the range of 0.7:1 to 1.4:1.
- 3. Magnetic recording medium according to claim 2, characterised in that the anionic polyurethane ionomer preferably contains 0.02 to 3% by weight of SO.sub.3.sup.- groups.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2914659 |
Apr 1979 |
DEX |
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Parent Case Info
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation of application Ser. No. 137,745, filed Apr. 7, 1980 now abandoned for Mangetic Recording Medium And A Process For Its Manufacture, now abandoned.
US Referenced Citations (6)
Foreign Referenced Citations (6)
Number |
Date |
Country |
2258685 |
|
FRX |
116248 |
|
DDX |
7313590 |
Jan 1974 |
NLX |
922905 |
Jan 1963 |
GBX |
1076688 |
Jan 1967 |
GBX |
1415618 |
Jan 1975 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
137745 |
Apr 1980 |
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