Heat-sealable paperboard structures and methods

Abstract

A heat-sealable paperboard structure including a paperboard substrate having a first major side and a second major side opposed from the first major side, a heat-sealable barrier coating on the first major side of the paperboard substrate, and a top coat positioned over the heat-sealable barrier coating, wherein the top coat forms a discontinuous layer over the heat-sealable barrier coating.

1 . A heat-sealable paperboard structure comprising:
 a paperboard substrate comprising a first major side and a second major side opposed from the first major side;   a heat-sealable barrier coating on the first major side of the paperboard substrate; and   a top coat positioned over the heat-sealable barrier coating, wherein the top coat forms a discontinuous layer over the heat-sealable barrier coating.   
     
     
         2 . The heat-sealable paperboard structure of  claim 1  wherein the top coat comprises a binder and a pigment. 
     
     
         3 . The heat-sealable paperboard structure of  claim 2  wherein a ratio of the pigment to the binder in the top coat is at least about 1:1, by weight. 
     
     
         4 - 6 . (canceled) 
     
     
         7 . The heat-sealable paperboard structure of  claim 2  wherein the binder comprises a latex. 
     
     
         8 . (canceled) 
     
     
         9 . The heat-sealable paperboard structure of  claim 2  wherein the pigment comprises calcium carbonate. 
     
     
         10 . (canceled) 
     
     
         11 . The heat-sealable paperboard structure of  claim 1  wherein the discontinuous layer has a coat weight ranging from about 0.1 lb/3000 ft 2  to about 4.0 lb/3000 ft 2 . 
     
     
         12 - 14 . (canceled) 
     
     
         15 . The heat-sealable paperboard structure of  claim 1  wherein the heat-sealable barrier coating comprises binder and pigment. 
     
     
         16 . The heat-sealable paperboard structure of  claim 15  wherein a ratio of the pigment to the binder in the heat-sealable barrier coating is at most 1:1 by weight. 
     
     
         17 - 25 . (canceled) 
     
     
         26 . The heat-sealable paperboard structure of claim  25  wherein the platy clay has an average aspect ratio of at least about 40:1. 
     
     
         27 . The heat-sealable paperboard structure of  claim 1  wherein the heat-sealable barrier coating has a coat weight ranging from about 4 lb/3000 ft 2  to about 20 lb/3000 ft 2 . 
     
     
         28 - 29 . (canceled) 
     
     
         30 . The heat-sealable paperboard structure of  claim 1  wherein the paperboard substrate comprises solid bleached sulfate. 
     
     
         31 . The heat-sealable paperboard structure of  claim 1  wherein the paperboard substrate has a basis weight ranging from about 80 lb/3000 ft 2  to about 300 lb/3000 ft 2 . 
     
     
         32 - 34 . (canceled) 
     
     
         35 . The heat-sealable paperboard structure of  claim 1  further comprising one or more coating layers positioned between the paperboard substrate and the heat-sealable barrier coating. 
     
     
         36 . The heat-sealable paperboard structure of  claim 1  further comprising one or more coating layers on the second major side. 
     
     
         37 . The heat-sealable paperboard structure of  claim 1  having a Parker Print Surface (PPS-10S) smoothness of at most about 3.1 μm. 
     
     
         38 - 39 . (canceled) 
     
     
         40 . The heat-sealable paperboard structure of  claim 1  having a 30-minute-water-Cobb rating of at most about 10 g/m 2 . 
     
     
         41 - 45 . (canceled) 
     
     
         46 . The heat-sealable paperboard structure of  claim 1  having a blocking rating of less than 2 at 50° C. and at 60 psi in a 24-hour period. 
     
     
         47 . (canceled) 
     
     
         49 . The heat-sealable paperboard structure of  claim 1  having a heat-sealability (% fiber tear) of at least about 95%. 
     
     
         50 . A container comprising the heat-sealable paperboard structure of  claim 1 . 
     
     
         51 . A method for manufacturing a heat-sealable paperboard structure comprising:
 preparing a heat-sealable barrier coating formulation comprising a binder and a pigment;   applying the heat-sealable barrier coating formulation to a first major side of a paperboard substrate to form a heat-sealable barrier coating;   preparing a top coat formulation comprising a binder and a pigment; and   applying the top coat formulation over the heat-sealable barrier coating to form a discontinuous layer of top coat over the heat-sealable barrier coating.   
     
     
         52 - 55 . (canceled)