| 摘要 |
879,205. Adhesive tapes. MINNESOTA MINING & MANUFACTURING CO. Oct. 31, 1957 [Nov. 2, 1956], No. 34036/57. Class 140. [Also in Group IV (a)] A normally tacky and pressure-sensitive adhesive composition which in the form of a thin coating on a flexible backing reacts upon moderate heating to a solvent resistant adherent state comprises a mixture of (1) a copolymer of (a) monomeric acrylic ester of non-tertiary alkyl alcohol the molecules of which have from 1 to 14 carbon atoms, the average being about 4 to 12 carbon atoms, more than half of the molecules having a carbon-to-carbon chain of at least four carbon atoms terminating at the hydroxyl oxygen atom, the chain containing at least half the total number of carbon atoms in the molecule, and (b) at least one copolymerizable monomer containing, bonded to an ethylenic carbon, at least one strongly polar group attached through a carbonyl radical, the monomer (b) comprising about 0.5 to 12% by weight of the total monomers ; and (2) a mutually miscible polyfunctional organic compound having at least two groups readily reactive to form primary bonds with the strongly polar groups in the copolymer, the ratio of the reactive groups in the polyfunctional compound to atoms other than hydrogen in the compound, excluding atoms in the reactive groups, extending from about 1 : 1 to 1 : 50. Specified copolymers (1) are isooctyl acrylate-acrylic acid, methylisoamyl acrylate-acrylic acid and isooctyl acrylate-acrylamide copolymers. Other polar monomers specified are methacrylic and itaconic acids. Also present in the copolymers may be small amounts of other monomers such as butadiene, isoprene, diallyl phthalate, methacrylate esters and vinyl chloride. Polyfunctional compounds (2) specified are ethylene and hexamethylene diamines, tetraethylene pentamine, the addition product of polymerized long chain fatty acids and polyfunctional primary and secondary amines, ethanolamine, 2-ethylhexanediol, polypropylene, glycol, isophthalyl dihydrazide and epoxy resins, e.g. the reaction product of epichlorhydrin and bisphenol. The above compositions, thinned with appropriate solvents are applied to flexible backings, e.g. made from polyethylene terephthalate or a vinylchlorideacetate copolymer, dried and insolubilized by heat-treatment. The flexible backing may be provided with a primer layer, e.g. one composed of an epoxy resin, polymeric polyamine and, optionally a butadiene-acrylonitrile rubber, and a backsize coating, e.g. a coating of an octadecyl acrylate-acrylic acid copolymer. |
