Packaging materials

Abstract

Abstract A packaging material for foodstuffs comprises a sheet material having on the rear face a water-based or water-borne cold seal adhesive applied thereto without a primer coat and on the front face a water-based or water-borne overprint varnish applied over the printed matter. The cold seal adhesive is applied to chosen areas of the rear face by conventional means and then dried. The cold seal adhesive may suitably be a combination of one or more cohesive latex materials such as synthetic rubber emulsions or butyl or nitrile rubber emulsions but more particularly natural rubber latex, combined with a water-based or water-borne synthetic coating resin, particularly a polyamide resin emulsion or dispersion an acrylic resin emulsion or dispersion a polystyrene resin emulsion or dispersion a polyester resin emulsion or dispersion a polyvinylidene chloride resin emulsion or dispersion or a combination of any of the above emulsions or dispersions with each other or with a polyvinyl ethylene emulsion a polyvinyl alcohol emulsion a polyvinyl acetate emulsion a carboxy methyl cellulose solution in water with or without the addition of waxes or antifoam agents. The sheet material is normally wound up on a reel for storage purposes, with the result that the rear face comes into contact with the front face. However it is one of the principal features of the present invention that the overprint varnish prevents damage to the printed matter and prevents the two faces adhering together during storage despite the conditions of pressure and ambient temperature found in the reel; and when the sheet material is unwound from the reel, the overprint varnish allows release of the rear face bearing the cold seal adhesive without blocking.

Inventors

• 👤 Brian A. McCarthy
• 👤 John P. McKeon

Bibliographic Details