Linerless double-coated pressure-sensitive adhesive tape
AssigneeMinnesota Mining and Manufacturing Company
InventorDonald L. Esmay
Life of this patent
Estimating the term…
Abstract
A linerless double-coated pressure-sensitive adhesive tape of the prior art is wound directly upon itself into a roll that can later be unwound without delamination or offsetting of adhesive. The novel tape differs from the prior tape in that the pressure-sensitive adhesive at each of its faces is a substantially solvent-free, crosslinked alkyl acrylate polymer and can be aggressively tacky for uses requiring high-performance adhesion.
Claims12
A linerless double-coated pressure-sensitive adhesive tape comprising a flexible support, at each face of which is a pressure-sensitive adhesive, which tape can be wound directly upon itself into a roll that can later be unwound without delamination or offsetting of adhesive, wherein the improvement comprises:
- each pressure-sensitive adhesive layer
- (a) is a polymerized product of a predominantly alkyl acrylate composition, the alkyl groups of which have an average of 4-12 carbon atoms, each said composition being physically compatible with the other,
- (b) is substantially solvent-free,
- (c) contains a photoinitiator,
- (d) is crosslinked, and
- (e) affords at each face a 180.degree. Peelback Value of at least 10 N/dm.
Method of making a linerless double-coated pressure-sensitive adhesive tape comprising the steps of
- (1) coating onto each face of a flexible support a substantially solvent-free photopolymerizable mixture comprising an alkyl acrylate, the alkyl groups of which have an average of 4-12 carbon atoms, each said photopolymerizable mixture being physically compatabile with the other said mixture, and a crosslinker, and
- (2) then exposing each coating to ultraviolet radiation to polymerize the acrylate to provide a pressure-sensitive adhesive layer which
- (a) is crosslinked, and
- (b) affords at each face a 180.degree. Peelback Value of at least 10 N/dm,
- which tape can be wound up adhesive face to adhesive face and later unwound without delamination or offsetting of adhesive.
Dependencies are inferred from the claim text.