Aseptic and liquid food packaging with aqueous multibarrier coatings and methods of making same

Abstract

Coatings for packaging materials and, more specifically, aqueous coatings for paperboard substrates and methods of applying the coatings. The aqueous coatings may include light blocking particles.

What is claimed is: 
     
         1 . A substrate for aseptic packaging, the substrate comprising at least a first layer and a second layer, wherein the first layer is disposed on a side of the substrate and the second layer disposed on the first layer, wherein each layer comprises a composition comprising an aqueous polymeric solution or dispersion dried to form a continuous film to provide distinct barrier functions. 
     
     
         2 . The substrate of  claim 1 , wherein the first layer composition forms an oxygen gas barrier and the second layer composition forms a moisture vapor or liquid barrier. 
     
     
         3 . The substrate of  claim 2 , wherein the first layer composition comprises a polyvinyl alcohol and the second layer composition comprises an acrylic latex dispersion. 
     
     
         4 . The substrate of  claim 1 , wherein the first and second layers are coated on a side of the substrate intended for contact with food or liquid contents for the aseptic packaging. 
     
     
         5 . The substrate of  claim 4 , further comprising a third layer, wherein the first, second, and third layers are coated on the side of the substrate, the third layer disposed on the second layer and being the top most layer. 
     
     
         6 . The substrate of  claim 1 , wherein one of the first layer or the second layer forms a barrier to light. 
     
     
         7 . The substrate of  claim 6 , wherein the barrier to light composition comprises a mixture of a carbon-black or aluminum particles and the composition of the other layer comprises a second polymer. 
     
     
         8 . The substrate of  claim 1 , further comprising a third layer and a fourth layer placed on a second side of the substrate opposite the first and second layers. 
     
     
         9 . The substrate of  claim 1 , wherein the substrate comprises a layer of paper or paperboard. 
     
     
         10 . A method of manufacturing aseptic packaging, comprising the steps of:
 a. providing a substrate, wherein the substrate comprises a layer of paper or paperboard;   b. providing a first coating composition;   c. providing a second coating composition; and   d. forming a plurality of barrier layers on a first side of the substrate.   
     
     
         11 . The method of  claim 10 , wherein the forming a plurality of barrier layers on a first side of the substrate comprises:
 i. forming first barrier layer by coating the first coating composition as a film onto a first side of the substrate and drying the first coating composition; and   ii. forming a second barrier layer by coating the second coating composition as a film on top of the first barrier layer and drying the second coating composition.   
     
     
         12 . The method of  claim 11 , before forming a plurality of barrier layers, providing a third coating composition, and when forming the plurality of barrier layers further comprises forming a third barrier layer by coating the third coating composition as a film on top of the second barrier layer and drying the third coating composition. 
     
     
         13 . The method of  claim 12 , wherein the third coating composition is the same as the first coating composition. 
     
     
         14 . The method of  claim 10 , wherein the forming a plurality of barrier layers on a first side of the substrate comprises forming the plurality of barriers simultaneously by applying the first and the second coating compositions via curtain-coating or slide hopper coating 
     
     
         15 . The method of  claim 10 , wherein the combination of the first barrier layer and the second barrier layer block oxygen and water vapor. 
     
     
         16 . The method of  claim 10 , wherein the plurality of barrier layers forms a barrier to light. 
     
     
         17 . The method of  claim 10 , wherein the first coating composition comprises a solution comprising a polyvinyl alcohol and the second coating composition comprises an acrylic latex dispersion.