Magnetic recording medium containing magnetic particles surface treated with a glycidyl compound
First Claim
1. A magnetic recording medium comprising a nonmagnetic support having thereon a magnetic recording layer which contains ferromagnetic particles dispersed in a binder, wherein the ferromagnetic particles have been surface-treated with a glycidyl compound having a molecular weight of 1,000 or less and having an epoxy equivalent of 200 g/eq. or less, wherein surface-treatment of the magnetic particles has been carried out by a process which comprises dispersing the glycidyl compound and the ferromagnetic particles in a portion of a solvent used for preparing a magnetic coating composition to form a first solution, and wherein a binder is added to the remainder of the solvent to form a second solution, and then the first and second solutions are added together, and the resultant mixture is then mixed, kneaded and dispersed to prepare a magnetic coating composition, and thereafter the resulting magnetic coating composition is coated on the nonmagnetic support, and then the magnetic coating composition is dried to form the magnetic recording layer.
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Accused Products
Abstract
A method for preparing a magnetic recording medium is disclosed, comprising the steps of (1) surface-treating ferromagnetic particles with a glycidyl compound having a molecular weight of 1,000 or less and having an epoxy equivalent of 200 g/eq. or less, (2) dispersing the surface-treated ferromagnetic particles with a binder to prepare a magnetic coating composition, (3) coating the resulting magnetic coating composition on a nonmagnetic support, and then (4) drying the magnetic coating composition.
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Citations
14 Claims
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1. A magnetic recording medium comprising a nonmagnetic support having thereon a magnetic recording layer which contains ferromagnetic particles dispersed in a binder, wherein the ferromagnetic particles have been surface-treated with a glycidyl compound having a molecular weight of 1,000 or less and having an epoxy equivalent of 200 g/eq. or less, wherein surface-treatment of the magnetic particles has been carried out by a process which comprises dispersing the glycidyl compound and the ferromagnetic particles in a portion of a solvent used for preparing a magnetic coating composition to form a first solution, and wherein a binder is added to the remainder of the solvent to form a second solution, and then the first and second solutions are added together, and the resultant mixture is then mixed, kneaded and dispersed to prepare a magnetic coating composition, and thereafter the resulting magnetic coating composition is coated on the nonmagnetic support, and then the magnetic coating composition is dried to form the magnetic recording layer.
- 2. A method for preparing a magnetic recording medium comprising the steps of (1) surface-treating ferromagnetic particles with a glycidyl compound having a molecular weight of 1,000 or less and having an epoxy equivalent of 200 g/eq. or less, wherein the step of surface-treating the magnetic particles comprises dispersing the glycidyl compound and the ferromagnetic particles in a portion of a solvent used for preparing a magnetic coating composition to form a first solution, (2) a binder is added to the remainder of the solvent to form a second solution, and then the first and second solutions are added together, and the resultant mixture is then mixed, kneaded and dispersed to prepare the magnetic coating composition, (3) coating the resulting magnetic coating composition on a nonmagnetic support, and then (4) drying the magnetic coating composition.
Specification