Method for forming co-extruded adhesive tapes

Claim 1

A method of forming a continuous sheet of adhesive tape comprising the steps of continuously and simultaneously co-extruding first, second, and third pressurized substantially uniformly dispersed molten streams through a co-extrusion die, said first stream comprising between approximately 20% and 60% by weight of an elastomeric based adhesive polymer, between approximately 0% and 55% by weight of fillers, between approximately 8% and 40% by weight of tackifiers, between approximately 0% and 6% by weight of processing aids, between approximately 0% and 60% by weight of reinforcing materials and between approximately 0% and 15% by weight of protective materials, said second pressurized stream comprising between approximately 25% and 90% by weight of a flexible thermoplastic and between approximately 5% and 80% by weight of an elastomerically compatible coupling agent, said third pressurized stream comprising either between approximately 80% and 100% by weight of a molten flexible thermoplastic or a mixture comprising between approximately 20% and 60% by weight of an elastomeric based adhesive polymer, between approximately 0% and 55% by weight of fillers, between approximately 8% and 40% by weight of tackifiers, between approximately 0% and 6% by weight of processing aids, between approximately 0% and 60% by weight of reinforcing materials and between approximately 0% and 15% by weight of protective materials, the compatibility of said coupling agent with both said thermoplastic and said adhesive polymer being greater than the compatibility of said thermoplastic with said adhesive polymer, material from said first, second and third streams merging in the interior of said die so that the material from said second stream is interposed between the material from said first and third streams, material from said first, second and third streams passing outwardly from said co-extrusion die as a continuous tape sheet of first, second and third intimately fused layers of material from said first, second and third streams, respectively.

Claim 2

A method of forming a continuous sheet of adhesive tape comprising the steps of continuously and simultaneously co-extruding first, second, and third pressurized substantially uniformly dispersed molten streams through a co-extrusion die, said first stream comprising between approximately 20% and 60% by weight of an elastomeric based adhesive polymer, between approximately 0% and 55% by weight of fillers, between approximately 8% and 40% by weight of tackifiers, between approximately 0% and 6% by weight of processing aids, between approximately 0% and 60% by weight of reinforcing materials and between approximately 0% and 15% by weight of protective materials, said second pressurized stream comprising between approximately 25% and 90% by weight of a flexible thermoplastic and between approximately 5% and 80% by weight of an elastomerically compatible coupling agent, said third pressurized stream comprising either between approximately 80% and 100% by weight of a molten flexible thermoplastic or a mixture comprising between approximately 20% and 60% by weight of an elastomeric based adhesive polymer, between approximately 0% and 55% by weight of fillers, between approximately 8% and 40% by weight of tackifiers, between approximately 0% and 6% by weight of processing aids, between approximately 0% and 60% by weight of reinforcing materials and between approximately 0% and 15% by weight of protective materials, the compatibility of said coupling agent with both said thermoplastic and said adhesive polymer being greater than the compatibility of said thermoplastic with said adhesive polymer, material from said first, second and third streams merging in the interior of said die so that the material from said second stream is interposed between the material from said first and third streams, material from said first, second and third streams passing outwardly from said co-extrusion die as a continuous tape sheet of first, second and third intimately fused layers of material from said first, second and third streams, respectively.

Claim 3

A method of forming a continuous sheet of adhesive tape comprising the steps of continuously and simultaneously co-extruding first, second, and third pressurized substantially uniformly dispersed molten streams through a co-extrusion die, said first stream comprising between approximately 20% and 60% by weight of an elastomeric based adhesive polymer, between approximately 0% and 55% by weight of fillers, between approximately 8% and 40% by weight of tackifiers, between approximately 0% and 6% by weight of processing aids, between approximately 0% and 60% by weight of reinforcing materials and between approximately 0% and 15% by weight of protective materials, said second pressurized stream comprising between approximately 25% and 90% by weight of a flexible thermoplastic and between approximately 5% and 80% by weight of an elastomerically compatible coupling agent, said third pressurized stream comprising either between approximately 80% and 100% by weight of a molten flexible thermoplastic or a mixture comprising between approximately 20% and 60% by weight of an elastomeric based adhesive polymer, between approximately 0% and 55% by weight of fillers, between approximately 8% and 40% by weight of tackifiers, between approximately 0% and 6% by weight of processing aids, between approximately 0% and 60% by weight of reinforcing materials and between approximately 0% and 15% by weight of protective materials, the compatibility of said coupling agent with both said thermoplastic and said adhesive polymer being greater than the compatibility of said thermoplastic with said adhesive polymer, said co-extrusion die having an outlet aperture therein having an elongated predetermined width extending in an X direction and a reduced height extending in a Y direction, said extrusion die having first, second and third inlet openings and first, second and third extrusion channels which extend from said first, second and third inlet openings, respectively toward said outlet aperture, said first, second and third extrusion channels merging in the interior of said die from positions wherein they are spaced in said Y direction to form a common outlet channel which opens outwardly through said outlet aperture, said outlet channel having a width which is substantially equal to said predetermined width at the point where said outlet channel opens outwardly through said outlet aperture, material from said first, second and third streams merging in the interior of said die so that the material from said second stream is interposed between the material from said first and third streams, material from said first, second and third streams passing outwardly through said outlet aperture as a continuous tape sheet of first, second and third intimately fused layers of material from said first, second and third streams, respectively.

Claim 4

A method of forming a continuous sheet of adhesive tape comprising the steps of continuously and simultaneously co-extruding first, second, and third pressurized substantially uniformly dispersed molten streams through a co-extrusion die, said first stream comprising between approximately 20% and 60% by weight of an elastomeric based adhesive polymer, between approximately 0% and 55% by weight of fillers, between approximately 8% and 40% by weight of tackifiers, between approximately 0% and 6% by weight of processing aids, between approximately 0% and 60% by weight of reinforcing materials and between approximately 0% and 15% by weight of protective materials, said second pressurized stream comprising between approximately 25% and 90% by weight of a flexible thermoplastic and between approximately 5% and 80% by weight of an elastomerically compatible coupling agent, said third pressurized stream comprising either between approximately 80% and 100% by weight of a molten flexible thermoplastic or a mixture comprising between approximately 20% and 60% by weight of an elastomeric based adhesive polymer, between approximately 0% and 55% by weight of fillers, between approximately 8% and 40% by weight of tackifiers, between approximately 0% and 6% by weight of processing aids, between approximately 0% and 60% by weight of reinforcing materials and between approximately 0% and 15% by weight of protective materials, the compatibility of said coupling agent with both said thermoplastic and said adhesive polymer being greater than the compatibility of said thermoplastic with said adhesive polymer, said co-extrusion die having an outlet aperture therein having an elongated predetermined width extending in an X direction and a reduced height extending in a Y direction, said extrusion die having first, second and third inlet openings and first, second and third extrusion channels which extend from said first, second and third inlet openings, respectively toward said outlet aperture, said first, second and third extrusion channels merging in the interior of said die from positions wherein they are spaced in said Y direction to form a common outlet channel which opens outwardly through said outlet aperture, said outlet channel having a width which is substantially equal to said predetermined width at the point where said outlet channel opens outwardly through said outlet aperture, material from said first, second and third streams merging in the interior of said die so that the material from said second stream is interposed between the material from said first and third streams, material from said first, second and third streams passing outwardly through said outlet aperture as a continuous tape sheet of first, second and third intimately fused layers of material from said first, second and third streams, respectively.