MAGNETIC TAPE AND METHOD OF MANUFACTURING THE SAME
First Claim
1. A magnetic tape,which comprises a magnetic layer comprising ferromagnetic powder and binder on a surface on one side of a nonmagnetic support and a backcoat layer comprising nonmagnetic powder and binder on a surface on the other side of the nonmagnetic support,wherein a centerline average surface roughness Ra as measured on a surface on the magnetic layer side of the magnetic tape is less than or equal to 1.8 nm,a logarithmic decrement as determined by a pendulum viscoelasticity test on the surface on the magnetic layer side of the magnetic tape is less than or equal to 0.050, and a logarithmic decrement as determined by a pendulum viscoelasticity test on a surface on the backcoat layer side of the magnetic tape is less than or equal to 0.060.
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Accused Products
Abstract
The magnetic tape has a magnetic layer containing ferromagnetic powder and binder on the surface on one side of a nonmagnetic support and has a backcoat layer containing nonmagnetic powder and binder on the surface on the other side thereof, wherein the centerline average surface roughness Ra as measured on the surface on the magnetic layer side of the magnetic tape is less than or equal to 1.8 nm, the logarithmic decrement as determined by a pendulum viscoelasticity test on the surface on the magnetic layer side of the magnetic tape is less than or equal to 0.050, and the logarithmic decrement as determined by a pendulum viscoelasticity test on the surface on the backcoat layer side is less than or equal to 0.060.
101 Citations
16 Claims
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1. A magnetic tape,
which comprises a magnetic layer comprising ferromagnetic powder and binder on a surface on one side of a nonmagnetic support and a backcoat layer comprising nonmagnetic powder and binder on a surface on the other side of the nonmagnetic support, wherein a centerline average surface roughness Ra as measured on a surface on the magnetic layer side of the magnetic tape is less than or equal to 1.8 nm, a logarithmic decrement as determined by a pendulum viscoelasticity test on the surface on the magnetic layer side of the magnetic tape is less than or equal to 0.050, and a logarithmic decrement as determined by a pendulum viscoelasticity test on a surface on the backcoat layer side of the magnetic tape is less than or equal to 0.060.
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10. A method of manufacturing a magnetic tape,
wherein the magnetic tape is a magnetic tape which comprises a magnetic layer comprising ferromagnetic powder and binder on a surface on one side of a nonmagnetic support and a backcoat layer comprising nonmagnetic powder and binder on a surface on the other side of the nonmagnetic support, wherein a centerline average surface roughness Ra as measured on a surface on the magnetic layer side of the magnetic tape is less than or equal to 1.8 nm, a logarithmic decrement as determined by a pendulum viscoelasticity test on the surface on the magnetic layer side of the magnetic tape is less than or equal to 0.050, and a logarithmic decrement as determined by a pendulum viscoelasticity test on a surface on the backcoat layer side of the magnetic tape is less than or equal to 0.060, and wherein the method comprises forming a magnetic layer and forming a backcoat layer, wherein the forming of a magnetic layer comprises: -
coating a magnetic layer-forming composition comprising ferromagnetic powder, binder, a curing agent, and solvent on a nonmagnetic support, either directly or over another layer, to form a magnetic coating layer, drying the magnetic coating layer by a heat treatment, and curing the magnetic coating layer by subjecting the magnetic coating layer to a curing treatment, with cooling the magnetic coating layer after the coating but before the drying, and burnishing a surface of the magnetic coating layer after the drying but before the curing; and forming of a backcoat layer comprises; coating a backcoat layer-forming composition comprising nonmagnetic powder, binder, a curing agent, and solvent on a surface of the nonmagnetic support to form a nonmagnetic coating layer, drying the nonmagnetic coating layer by a heat treatment, and curing the nonmagnetic coating layer by subjecting the nonmagnetic coating layer to a curing treatment, with cooling the nonmagnetic coating layer after the coating but before the drying, and burnishing a surface of the nonmagnetic coating layer after the drying but before the curing. - View Dependent Claims (11, 12, 13, 14, 15, 16)
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Specification