Minnesota Mining and Manufacturing Company

Andrew H Wong

Roy Wong

Shih-Lai Lu

James J Pedginski

An end portion for a container having a preformed opening therein and an easy-open closure system therefor, the closure system comprising an exterior tape over the opening which is manually removable, the tape being adhered by an adhesive which comprises the reaction mixture of an aryl isocyanate, an aliphatic glycol, and a defined mixture of hydroxy terminated polyesters.

Easy open closure system

A tape comprising a polypropylene backing coated on one surface with an adhesive. The backing is biaxially oriented to provide a secant modulus of elasticity measured at one percent elongation in its longitudinal direction of at least about 25.times.10.sup.5 kilopascals, will break before it can be stretched in its longitudinal direction by about 55 percent and can be transversely cut by forces of less than about 13 newtons on the cutters of commercially available tabletop tape dispensers.

Dispensable polypropylene adhesive-coated tape

Polyester films consisting of a homogeneous fused, intimate mixture of polyethylene terephthalate (PET) with sufficient polytetramethylene terephthalate (PTMT) to increase film tear strength in excess of 10%. Mixed PET and PTMT resins are extruded and used to produce unoriented, uniaxially oriented, and biaxially oriented polyester films with significantly increased tear strengths. Increased tear strengths are exhibited at different PET-PTMT weight ratios depending upon the orientation of the film.

Growing community of inventors

Saint Paul, MN, United States of America

Andrew H Wong