Method of and compositions for applying heat-sealing coatings to sheet materials

摘要

A composition for applying a heat-sealing coating to flexible sheet material comprises, dissolved in a volatile organic solvent, a thermoplastic film-forming substance and a plasticizer consisting of a mixture of substances containing at least 50% by weight of para-toluene sulphonic acid cyclohexylamide. The thermoplastic film-forming substance may be nitrocellulose, cellulose acetate, tri-acetate or acetate-butyrate, ethyl cellulose, polyvinyl chloride, polyvinyl acetate, polyvinyl acetal, polyvinyl butyral, polyvinyl formal, a copolymer of vinyl chloride and vinyl acetate, polystyrene, a polyacrylate, a chlorinated rubber, or a natural resin such as shellac. Paratoluene sulphonic acid cyclohexylamide may be used in admixture with one or more of di-n-butyl phthalate, di-isobutyl phthalate, di (2-ethyl-hexyl) phthalate, diamyl phthalate, di-cyclohexyl phthalate or di(methylcyclohexyl) phthalate. The proportion of total plasticizer used is preferably within 15-100% of the weight of the thermoplastic film-forming substance. Conventional additives may be incorporated, e.g. rosin-modified alkyd resin, paraffin wax, calcium carbonate or zinc stearate. Specified solvents include ethyl and butyl alcohols, ethyl and butyl acetates, toluene, methyl ethyl ketone and cyclohexanone. Flexible sheet materials specified include paper, waxed paper, gelatin, aluminium foil, regenerated cellulose, cellulose esters and cellulose ethers.ALSO:A composition for applying a heat-sealing coating to flexible sheet material comprises, dissolved in a volatile organic solvent, a thermoplastic film-forming substance and a plasticiser consisting of a mixture of substances containing at least 50% by weight of paratoluene sulphonic acid cyclohexylamide. The thermoplastic film-forming substance may be nitrocellulose, cellulose acetate, tri-acetate or acetate-butyrate, ethyl cellulose, polyvinyl chloride, polyvinyl acetate, polyvinyl acetal, polyvinyl butyral, polyvinyl formal, a copolymer of vinyl chloride and vinyl acetate, polystyrene, a polyacrylate, a chlorinated rubber, or a natural resin such as shellac. Paratoluene sulphonic acid cyclohexylamide may be used in admixture with one or more of di-n-butyl phthalate, di-isobutyl phthalate, di-(2-ethylhexyl) phthalate, diamyl phthalate, dicyclohexyl phthalate or di(methylcyclohexyl) phthalate. The proportion of total plasticiser used is preferably within 15-100% of the weight of the thermoplastic film-forming substance. Conventional additives may be incorporated, e.g. rosin-modified alkyd resin, paraffin wax, calcium carbonate or zinc stearate. Specified solvents include ethyl and butyl alcohols, ethyl and butyl acetates, toluene, methyl ethyl ketone and cyclohexanone. Flexible sheet materials specified include paper, waxed paper, gelatin, aluminium foil, regenerated cellulose, cellulose esters and cellulose ethers.