GB1092499A - Adhesive compositions, methods for their preparation, and sheet materials coated therewith - Google Patents

Abstract

An adhesive composition is obtained by vigorously mixing together at a temperature below 60 DEG C. an aqueous emulsion containing small discrete particles of a thermoplastic polymer of a mixture of thermoplastic polymers with a molten normally solid plasticizer or a mixture of normally solid plasticizers that is compatible with the thermoplastic polymer to form an emulsion of the water-in-oil type in which the discrete particles of the thermoplastic polymer are coated with a thin protective film of water and are dispersed throughout the fluid matrix consisting of the normally solid plasticizer. Thermoplastic polymers exemplified are vinylpyrrolidone/ethyl acrylate copolymers, ethylene/vinyl acetate copolymers, vinyl pyrrolidone/styrene copolymer, styrene/butadiene copolymers, vinyl acetate/vinyl pyrrolidone copolymers and mixtures thereof. Preferred plasticizers are tricyclohexyl citrate, dicyclohexyl phthalate, pentaerythritol tetrabenzoate, glycerol tribenzoate, trimethylolethane tribenzoate, N - cyclohexyl - p - toluenesulphonamide, and sucrose benzoate. The compositions are used in the production of adhesive tapes (see Division B2).ALSO:A method of making a sheet material having a surface area that is covered by an essentially dry, non-tacky thin film of an adhesive composition which becomes tacky at a pre-selected temperature above room temperature and thereafter remains tacky for a period of days, comprises vigorously mixing together at a temperature below about 60 DEG C an aqueous emulsion comprising discrete particles of a thermoplastic polymer or a mixture of thermoplastic polymers with a molten normally solid plasticiser or a mixture of normally solid plasticisers that is compatible with the thermoplastic polymer to form an emulsion of the water-in-oil type in which the discrete particles of the thermoplastic polymer are coated with a thin protective film of water and are disposed throughout the fluid matrix consisting of the normally solid plasticiser, and subsequently coating the sheet material with a film of the resulting emulsion and drying the film. Various thermoplastic polymers and plasticisers are exemplified (see Division C3). The Examples relate to the application of the adhesive composition to paper labels which are then adhered to polyethylene.