Film Having a Liquid Absorbed Therein

Abstract

The present invention relates to a film having a liquid at least partially absorbed therein, wherein the liquid has been applied to a surface of the film and prior to application of the liquid to the surface, the surface has been subjected to a surface activation treatment such that the surface has a surface energy of at least about 50 dynes.

1 . (canceled) 
     
     
         2 . The method of  claim 18  wherein the surface activation treatment is selected from the group consisting of plasma treatment, flame treatment, corona discharge, UV irradiation, electron beam irradiation, and gamma irradiation. 
     
     
         3 . (canceled) 
     
     
         4 . (canceled) 
     
     
         5 . (canceled) 
     
     
         6 . The method of  claim 18  wherein the liquid has been applied to the surface in an amount of between about 0.4 to about 10 mg/cm 2 . 
     
     
         7 . (canceled) 
     
     
         8 . (canceled) 
     
     
         9 . (canceled) 
     
     
         10 . (canceled) 
     
     
         11 . (canceled) 
     
     
         12 . (canceled) 
     
     
         13 . (canceled) 
     
     
         14 . (canceled) 
     
     
         15 . (canceled) 
     
     
         16 . (canceled) 
     
     
         17 . (canceled) 
     
     
         18 . A method of preparing a nylon film having a liquid at least partially absorbed therein comprising subjecting a surface of the nylon film to a surface activation treatment such that the surface has a surface energy of at least about 70 dynes, then applying a liquid to the surface such that the liquid is at least partially absorbed into the film, wherein an amount of liquid able to be absorbed by the nylon film after said surface activation is greater than an amount of liquid able to be absorbed before said activation. 
     
     
         19 . The method of  claim 18 , wherein the surface activation treatment is corona discharge. 
     
     
         20 . The method of  claim 19 , wherein the corona discharge has been conducted at a power level of between about 50 and 1000 W-m/M 2 . 
     
     
         21 . The method of  claim 20 , wherein the power level is between about 100 to about 600 W-m/M 2 . 
     
     
         22 . The method of  claim 18 , wherein the film is in the form of a food packaging film, whereby in use the surface is an inner surface of the film. 
     
     
         23 . (canceled) 
     
     
         24 . The method of  claim 18 , wherein the nylon film comprises a nylon and a crosslinked polyvinylpyrrolidone. 
     
     
         25 . The method of  claim 24  wherein the film is a monolayer. 
     
     
         26 . The method of  claim 22  wherein the food packaging film has at least two layers, a first layer comprising the a nylon and an optional crosslinked polyvinylpyrrolidone, and a second layer comprising a layer of a polyolefin material, whereby in use, the first nylon layer is an inner layer and the second polyolefin layer is an outer layer thereof. 
     
     
         27 . The method of  claim 22 , wherein the film is in the form of a tubular casing. 
     
     
         28 . The method of  claim 27 , wherein after the liquid is applied to the surface, the casing is shirred. 
     
     
         29 . The method of  claim 22  wherein the liquid consists essentially of water. 
     
     
         30 . The method of  claim 22 , wherein the liquid is a composition comprising at least one additive for transfer to a packaged food article packaged in the food packaging film. 
     
     
         31 . The method of  claim 30 , wherein the additive is selected from the group consisting of a coloring agent, a flavoring agent, and a coloring and flavoring agent. 
     
     
         32 . The method of  claim 30 , wherein the additive comprises a Maillard reagent. 
     
     
         33 . The method of  claim 18 , wherein after the liquid has been applied to the surface, the film is passed between a pair of nip rolls and a spacing between the nip rolls is set at a distance less than the thickness of the film. 
     
     
         34 . (canceled) 
     
     
         35 . (canceled) 
     
     
         36 . (canceled) 
     
     
         37 . (canceled) 
     
     
         38 . (canceled) 
     
     
         39 . (canceled) 
     
     
         40 . (canceled) 
     
     
         41 . (canceled) 
     
     
         42 . The method of  claim 18  wherein the nylon film consists of (a)(i) one or more aliphatic primary diamine and one or more aliphatic dicarboxylic acid, (ii) an omega-aminocarboxylic acid, (iii) an omega-aminocarboxylic lactam, or (iv) a mixture of two or three of (i), (ii), and (iii), and optionally, (b) a crosslinked polyvinylpyrrolidone. 
     
     
         43 . The method of  claim 18  wherein the nylon is nylon  6 . 
     
     
         44 . The method of  claim 26  wherein the food packaging film has a third nylon layer over the polyolefin layer. 
     
     
         45 . The method of  claim 44  wherein the third layer comprises nylon  66 . 
     
     
         46 . The method of  claim 18 , wherein the liquid is absorbed to a depth of up to about one-half of a thickness of the nylon surface layer. 
     
     
         47 . The method of  claim 18 , wherein the liquid is absorbed to a depth of up to about 5 microns of a thickness of the nylon surface layer. 
     
     
         48 . The method of  claim 18 , wherein the surface of the film receives energy of a watt density of at least 50 W-min/m 2 . 
     
     
         49 . A method of preparing a nylon film having a liquid at least partially absorbed therein comprising subjecting a surface of the nylon film to a surface activation treatment by an application of energy such that the surface receives energy of a watt density of at least about 75 W-min/m 2 , then applying a liquid to the surface such that the liquid is at least partially absorbed into the film, wherein an amount of liquid able to be absorbed by the nylon film after said surface activation is greater than an amount of liquid able to be absorbed before said activation. 
     
     
         50 . The method of  claim 49 , wherein the surface of the nylon film receives energy of a watt density of up to about 500 W-min/m 2 . 
     
     
         51 . The method of  claim 49 , wherein the liquid is absorbed up to about one-half of a thickness of the nylon film. 
     
     
         52 . The method of  claim 49 , wherein the liquid is absorbed to a depth of up to about 5 microns of a thickness of the nylon surface layer. 
     
     
         53 . The method of  claim 49 , wherein the liquid has been applied to the surface, the film is passed between a pair of nip rolls and a spacing between the nip rolls is set at a distance less than the thickness of the film.