US 5,686,142 A · Process of producing magnetic recording tape having textured backcoat

Abstract

Coated polymeric sheet comprising polymer substrate a cross-linked polymer, wherein the coating is characterized by: A. being smooth, having a surface roughness not greater than 0.05 nanometers R.sub.a, except that; B. in the otherwise smooth surface, a multiplicity of depressions having depth ranging from 1 to 90% of the thickness of the coating. Backside coatings (containing carbon black in the cross-linked polymer) for magnetic recording tapes benefit from this invention by improved winding characteristics. The concept described is a replacement for rough random surface texture, formerly used in backside coatings, with a controlled surface texture. The process disclosed can also be used to make alphanumeric symbols on the pigment binder coating.

Claims13

Dependent claims

A process for making a polymeric sheet having a multiplicity of surface discontinuities comprising the steps of:

A. coating a surface of polymeric sheet with a fluid dispersion comprising a cross-linkable polymer composition;
B. before the fluid dispersion has dried or the crosslinkable polymer composition has substantially cross-linked, contacting the surface of the polymeric sheet opposite the surface coated in step A with a roller, the surface of which roller has a plurality of discontinuities having an aspect ratio of greater than 1.5/1 and the surface of which roller is at a temperature at least 2.degree. C. higher than the temperature of the fluid dispersion, but lower than the glass transition temperature of the polymeric sheet, for a time sufficient to form a plurality of discontinuities in the fluid dispersion coated on the first surface, said discontinuities in the fluid dispersion corresponding to the discontinuities on the roller;
and
C. cross-linking the cross-linkable polymer.

1 more element

Dependencies are inferred from the claim text.

Process of producing magnetic recording tape having textured backcoat

Life of this patent

Process of producing magnetic recording tape having textured backcoat

Life of this patent

Abstract

Claims13