Non-blocking coating composition
AssigneeAmerican Can Company
InventorDale Clifford Wiesman
Life of this patent
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Abstract
A flexible packaging sheet material bearing a tacky wax composition coating and a non-blocking overcoating in the form of a continuous film of an ethylene-vinyl acetate copolymer which incorporates between 10 and 35 percent by weight of solid low to medium density polyethylene particles of a size smaller than about 50 microns.
Claims8
A flexible packaging sheet material bearing on its surface a coating of a normally tacky heat-sealable wax composition selected from the group consisting of (1) microcrystalline petroleum wax and polyisobutylene and (2) ethylene-vinyl acetate copolymer, petroleum wax and a tackifying resin, (3) microcrystalline wax, petrolatum and polyisobutylene and (4) ethylene-vinyl acetate copolymer, paraffin wax, butyl rubber, rosin ester and microcrystalline wax, there being applied to the surface of said wax composition coating, as a non-blocking overcoating, between 0.75 and 4.0 pounds per ream of a composition comprising (a) between 65 and 90 weight percent of an ethylene-vinyl acetate copolymer having a melt index between about 20 and 40 and a vinyl acetate content of between 18 and 30% and (b) between 10 and 35 weight percent of a particulate polyethylene having a density between about 0.91 and 0.94 and an average particle size of between about 20 and 50 microns evenly dispersed throughout the overcoating.
A flexible packaging sheet material selected from the group consisting of (A) cellophane and (B) a laminated web comprising successive layers of paper, polyethylene and aluminum foil;
- said material bearing on its surface a coating of a normally tacky heat-sealable wax composition selected from the group consisting of (1) microcrystalline petroleum wax and polyisobutylene and (2) ethylene-vinyl acetate copolymer, petroleum wax and a tackifying resin, said coated sheet material having applied to the surface of the wax coating, as a non-blocking overcoating, between about 0.75 and 4.0 lbs. per ream of a composition comprising (a) between about 65 and 90 weight percent of an ethylene-vinyl acetate copolymer having a melt index between about 20 and 40 and a vinyl acetate content of between about 18 and 30% and (b) between 10 and 35 weight percent of a particulate polyethylene having a density between about 0.91 and 0.94 and an average particle size of between about 20 and 50 microns evenly dispersed throughout the overcoating.
Dependencies are inferred from the claim text.