GB1014321A - Fog resistant polyolefin film - Google Patents

Abstract

Polyolefin films are rendered anti-fogging by coating one or more surfaces of the film in conventional manner with a composition comprising (a) at least one wetting agent, (b) at least one water-soluble polymeric film-forming agent, and (c) at least 10% by weight of (a) of at least one water-soluble inorganic material. In general, (a) comprises 1 part by weight, (b) 0.25-1 parts and (c) 1-8 parts. It is preferred that (a) be an anionic or nonionic wetting agent; of many suitable substances named, sodium dodecylbenzene sulphonate, lauryl sulphate, N-oleoyl taurate and N-lauroyl sarcosinate are preferred. Many suitable film-forming agents (b) are also referred to, of which sodium carboxymethyl cellulose, methyl hydroxyethyl cellulose, hydroxymethyl cellulose and polyoxyethylene are especially favoured. Suitable salts (c) include sodium pyrophosphate, silicate and acetate. The polyolefin films to which the coating is applied, generally in amounts of about 0.0001 g./in.2 to provide a coating 0.00025-0.005 inch thick, comprise polyethylene or -propylene, or copolymers of ethylene and propylene either with each other or with other specified monomers. As an "anti-blocking agent," various natural and synthetic waxes, starches, fatty amides, silica or clays may be added to the composition in amounts of 100-600% of (a).ALSO:Polyolefin films are rendered anti-fogging by coating one or more surfaces of the film in conventional manner with a composition comprising (a) at least one wetting agent, (b) at least one water soluble polymeric film-forming agent, and (c) at least 10% by weight of (a) of at least one water soluble inorganic material. In general, (a) comprises 1 part by weight, (b) 0,25-1 parts and (c) 1-8 parts. It is preferred that (a) be an anionic or nonionic wetting agent; of many suitable substances named, sodium dodecylbenzene sulphonate, lauryl sulphate, N-oleoyl taurate and N-lauroyl sarcosinate are preferred. Many suitable film-forming agents (b) are also referred to, of which sodium carboxymethyl-cellulose, methyl hydroxyethyl cellulose, hydroxymethyl cellulose and polyoxyethylene are especially favoured. Suitable salts (c) include sodium pyrophosphate, silicate and acetate. The polyolefin films to which the coating is applied, generally in amounts of about 0,0001 g./inch2 to provide a coating 0,00025-0,005 inch thick, comprise poly-ethylene or -propylene, or copolymers of ethylene and propylene either with each other or with other specified monomers. As an "antiblocking agent", various natural and synthetic waxes, starches, fatty amides, silica or clays may be added to the composition in amounts of 100-600% of (a).