Ruban adhésif

摘要

922,350. Extensible perforated adhesive tape. B. B. BLACKFORD. May 19, 1960 [May 19, 1959], No. 17759/60. Class 140. An extensible pressure-sensitive adhesive tape, which can be readily torn into pieces of varying lengths, comprises an extensible film backing, a pressure-sensitive adhesive coating on said backing, and a plurality of closely spaced tear zones extending across the tape, the tear zones comprising spaced perforations 12 extending across the tape, the distance A between adjacent perforations in a tear zone being less than the distance B between adjacent tear zones. The distance A between adjacent perforations in a tear zone may be at least 10% less than the distance B between adjacent tear zones. The distance between adjacent tear zones may not exceed more than about “ inch. The perforations 12 forming a tear zone may be in a straight line 13 extending across the tape, or may be in two substantially parallel lines 131, the perforations 121 in one line being offset with respect to the perforations in the adjacent line. The perforations extending through the backing and adhesive may provide for each square inch of backing, an open area of between 0.01 and 0.15 square inch. The backing may be of a thermoplastic material and the edges of the perforations are reinforced with a bead 14 of the material e.g. an extensible vinyl film such as a plasticized polyvinyl chloride film which may contain 23 to 50% by weight plasticizer based on the weight of the backing. The perforations may be circular, formed with rounded edges and may have a diameter of from 0.002 to 0.02 inch. The backing may be primed prior to being coated with the adhesive. Specification 673,043 is referred to.