Claims
- 1. 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.
- 2. A linerless double-coated tape as defined in claim 1 wherein the pressure-sensitive adhesive at each face of the support has a 180.degree. Peelback Value of at least 30 N/dm.
- 3. A linerless double-coated tape as defined in claim 1 having at opposite faces of the support pressure-sensitive adhesives which are chemically different.
- 4. A linerless double-coated tape as defined in claim 1 having the same pressure-sensitive adhesive at both faces of the support.
- 5. A linerless double-coated tape as defined in claim 4 wherein said flexible support is a porous web embedded in a single pressure-sensitive adhesive layer.
- 6. A linerless double-coated tape as defined in claim 1 wherein the pressure-sensitive adhesive at at least one face of its support is a copolymer of alkyl acrylate and at least one copolymerizable polar acrylic monomer in an amount providing up to 12 mol percent of total monomers.
- 7. A linerless double-coated tape as defined in claim 6 wherein said polar monomer is one or more of acrylic acid, methacrylic acid, itaconic acid, acrylamide, methacrylamide, acrylonitrile, methacrylonitrile, and N-vinyl-2-pyrrolidone.
- 8. A linerless double-coated tape as defined in claim 7 wherein said copolymer is a copolymer of at least one of vinyl toluene, vinyl chloride, vinylidene chloride, styrene, and diallyl phthalate in amounts providing up to 5 mol percent of total monomer.
- 9. A linerless double-coated tape as defined in claim 1 which is wound directly upon itself into a roll.
- 10. 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.
- 11. Method as defined in claim 10 wherein prior to step (1) and before adding the crosslinker, the photopolymerizable mixture is first partially polymerized by ultraviolet radiation to provide a syrup having a coatable viscosity.
- 12. Method as defined in claim 10 including the further step
- (3) winding the tape directly upon itself into a roll.
CROSS-REFERENCE TO RELATED APPLICATION
This application is a continuation-in-part of Applicant's copending application Ser. No. 439,047, filed Nov. 3, 1982.
US Referenced Citations (8)
Foreign Referenced Citations (1)
Number |
Date |
Country |
747341 |
Nov 1966 |
CAX |
Continuation in Parts (1)
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Number |
Date |
Country |
Parent |
439047 |
Nov 1982 |
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