GB892818A - Low adhesion coatings - Google Patents

Abstract

892,818. Low adhesion coatings; laminates. MINNESOTA MINING & MANUFACTURING CO. July 3, 1958 [July 3, 1957], No. 21348/58. Class 140. A normally tacky pressure-sensitive adhesive sheet or tape, which may be in roll form, comprises a flexible backing having a coating of pressure-sensitive adhesive on one face, and on the other face a low adhesion backsize formed of a solid oleophobic fluorocarbon polymer which does not have a tack temperature, which is defined as the lowest temperature at which the polymer exhibits tack, below 60‹ C. and which has a molecular structure including non- fluorinated organic groups which bind to the flexible backing. A liner having a low adhesive coating comprising the solid oleophobic fluorocarbon polymer on one or both sides may be wound into rolls of double-coated pressuresensitive adhesive tapes, used as spacers, or applied to articles having an adhesive surface. The backing may be non-fibrous, e.g. films of regenerated cellulose, cellulose acetate or polyester, such as the polyester of ethylene glycol and terephthalic acid, or fibrous, e.g. dense highly calendered paper, felted or woven backings made from textile fibres which may be sized, or paper which may be sized with glue, casein which may be insolubilized with formaldehyde, shellac, alkyd resin, or a cellulose derivative such as ethyl cellulose or cellulose acetate. The adhesive may comprise a natural or synthetic rubber blended with a tackifier resin, e.g. a terpene resin. Suitable fluorocarbon polymers, which may be cross-linked or vulcanized, are fluoropolymethacrylates, e.g. 1,1-dihydroperfluoro alkylate methacrylate polymers such as poly (1,1-dihydroperfluoro hexyl methacrylate), fluoro-polyvinyl carbamates (urethanes), e.g. the reaction product of polyvinyl alcohol (partially hydrolysed polyvinyl acetate) with 1,1-dihydro perfluoro alkyl isocyanate wherein the perfluoroalkyl chain contains 3 to 12 carbon atoms, thermosetting polymers such as fluorotriazine-formaldehyde, e.g. condensation product of N-methyl perfluoro octane sulphonamido diamino triazine and formaldehyde, homo-polymers or copolymers of a fluorovinyl monomer and a comonomer which may or may not be fluorinated, e.g. polymers of vinyl esters of perfluoroalkane sulphonamido alkylene monocarboxylic acids such as the vinyl ester of N-methyl, N-perfluoro-octane sulphonyl glycine, and polymers of the methacrylate esters of N-alkyl, N-alkanol perfluoro alkane sulphonamides, e.g. methacrylate ester of N-ethyl N-ethanol perfluoro-octane sulphonamide.