Adhesive tape

Abstract

A manufacturing method of adhesive tape, comprising steps of: preparing a raw material of a biaxially drawn film or sheet; applying a release agent on a back surface of the film; applying an adhesive agent on a front surface of the film; subjecting the raw material to uniaxial drawing under heated conditions without deteriorating releasing and adhesive performance of the raw material to produce a base material of an adhesive tape having high-strength and low-elongation. The obtained adhesive tape has long and narrow bubbles elongated in the uniaxial drawing direction thereon.

What is claimed is:  
     
         1 . An adhesive tape manufactured by a method comprising steps of: 
 preparing a raw material of a biaxially drawn film or sheet;    applying a release agent on a back surface of the film;    applying an adhesive agent on a front surface of the film; and    subjecting the raw material to uniaxial drawing under heated conditions without deteriorating releasing and adhesive performance of the raw material to produce a base material of an adhesive tape having high-strength and low-elongation.    
     
     
         2 . The adhesive tape as claimed in  claim 1 , in which the manufacturing method further comprises a post-heat treatment step of heating the drawn material, 
 the uniaxial drawing step and the post-heat treatment step involving heating the release agent and the adhesive agent sufficiently to complete their cure reactions as well as to remove a volatile component of the adhesive agent, which otherwise would evaporate and give off a foul smell in use.    
     
     
         3 . The adhesive tape as claimed in  claim 1 , in which the uniaxial drawing step is performed under drawing conditions where width, thickness, draw ratio, temperature, speed and period of time are so set suitably in given ranges that a resultant adhesive tape will possess desired width, thickness, strength and elongation.  
     
     
         4 . The adhesive tape as claimed in  claim 1 , in which the manufacturing method further comprises a step of slitting of the raw material at a predetermined width before the uniaxial drawing step.  
     
     
         5 . An adhesive tape as claimed in  claim 1 , wherein long and narrow bubbles elongated in the direction of the uniaxial drawing are seen on the adhesive tape.