Recording diskette, esp magnetic disk with flanged hub bonded to disk - with cure, pressure-sensitive or hot melt adhesive, bonding process and use of light detector and fluorescent marker to control amt applied

摘要

Recording diskette has a ring-shaped disk with upper and lower surfaces and a hub with circular flanged edge, bonded to the disk with a cured, pressure-sensitive adhesive (I), which has a log. viscosity of ca. 0.3-1.0 dl/g in ethyl acetate (EtAc) soln. before cure. (I) consists of a crosslinked copolymer contg. a monomer (II) and ca. 0.025-1.0 (wt.) units of a crosslinking agent (III). (II) is a monomeric (meth)acrylate ester or 1-14C non-tert.-alcohol(s); and (III) a copolymerisable, mono-ethylenically unsatd. aromatic ketone monomer, free from ortho-aromatic OH gps. The claims also cover a diskette with hub bonded by a cured hot-melt adhesive (IV) and the process for bonding a magnetic disk medium to a hub. USE/ADVANTAGE - (I) is used as (V) (claimed). The disk pref. is a magnetic disk, e.g, microdiskette, micro-floppy disk, floppy disk or compact floppy disk used in a housing or cartridge. A continuous bonding process can be used and the amt. of adhesive applied can be controlled by adding a fluorescent dyestuff and using a light detector.