| 摘要 |
A pressure sensitive adhesive tape comprises an aggressively tacky electrically insulating water insoluble visco-elastic adhesive coating bonded to an electrically insulating hydrophobic film backing by an anti-static electrically conductive primer coating. The primer coating may include an antistatic ionogenic hydrophilic film-forming polymer and may have an electrical resistivity not exceeding 1010 ohms per square when in equilibrium with air having a 50% relative humidity. The antistatic polymers may be ionizable organic polymer salts which have a hydrocarbon backbone and attached salt groups; quaternary polymer salts such as dimethylamino ethyl methacrylate homopolymer or its copolymer with butyl acrylate, and poly-4-vinyl pyridine, quaternized with methyl bromide or allyl chloride; or sodium salts of sulphonated polymers such as sodium salts of sulphonated polystyrene, sulphonated polyvinyl toluene, sulphonated polystyrene-butyl acrylate copolymers, and poly benzyl sulphonate. The primer coating may be less than 5 microns thick. The film backing may be of cellulose acetate, polyester, and rigid (essentially non-plasticized) polyvinyl chloride. The film backing may carry a hydrophobic insulative low-adhesion backsize coating e.g. of polyvinyl N-octadecyl carbamate. The adhesive may comprise natural or synthetic rubber and tackifier resins, polyacrylates and polyvinyl alkyl ethers. The primer coating may contain a copolymer of vinyl pyrrolidone and vinyl acetate or polyvinyl methyl ether. |
