Paper articles exhibiting long term storageability and method for making same

Abstract

A method for increasing the long term storageability of a cellulosic paper or paperboard product. The method includes providing a paper or paperboard product made from cellulosic fibers having a basis weight ranging from about 80 to about 300 pounds per 3000 square feet. A holdout material is applied to at least one surface of the paper or paperboard product. The web is then coated with an ink receptive material selected from the group consisting of an aqueous acrylic polymer coating material, an aqueous biocidal agent and a combination of aqueous acrylic polymer coating material and aqueous biocidal agent and dried to provide a paper or paperboard product having enhanced long term storageability. Webs made according to the invention are suitable for making file folders which exhibit improve long term storageability by resisting damage from moisture and/or biological activity.

What is claimed is: 
     
         1 . A method for increasing the long term storageability of a cellulosic paper or paperboard product, comprising the steps of providing a paper or paperboard product made from cellulosic fibers having a basis weight ranging from about 80 to about 300 pounds per 3000 square feet, applying a holdout material to at least one surface of the paper or paperboard product to provide a sized web of paper or paperboard, coating the sized web with an ink receptive material selected from the group consisting of an aqueous acrylic polymer coating material, an aqueous biocidal agent and a combination of aqueous acrylic polymer coating material and aqueous biocidal agent to provide an ink receptive layer, drying the web at a first temperature to provide a coated web, wetting an uncoated side of the web with an aqueous fluid to reduce web curl, and drying the web at a second temperature to provide a paper or paperboard product having enhanced long term storageability. 
     
     
         2 . The method of  claim 1  wherein the ink receptive layer comprises an aqueous acrylic polymer coating material having a solids content ranging from about 30 to about 45 percent by weight. 
     
     
         3 . The method of  claim 2  wherein the aqueous acrylic polymer coating material comprises a film forming aqueous acrylic polymer coating material. 
     
     
         4 . The method of  claim 1  wherein the web is coated with an aqueous biocidal agent comprises a haloalkynyl carbamate latex emulsion. 
     
     
         5 . The method of  claim 4  wherein the aqueous biocidal agent comprises a latex emulsion containing from about 20 to about 30 percent by weight active biocidal ingredient 
     
     
         6 . The method of  claim 1  wherein the ink receptive material is applied to the web in an amount ranging from about 1.5 to about 3.0 pounds per 3000 square feet. 
     
     
         7 . The method of claim I wherein the web is dried at a first temperature ranging from about 150° to about 200° C. to provide a web temperature not exceeding about 85° C. 
     
     
         8 . The method of  claim 1  wherein the second temperature is lower than the first temperature. 
     
     
         9 . The method of  claim 1  wherein the ink receptive material is applied to the web using a coating process selected from the group consisting of a flexographic coater, a rod coater, a rotogravure costar, an offset gravure coater, a knife over roll coater, a lithographic coater, a dip coater, and a spray coater. 
     
     
         10 . The method of  claim 1  wherein the ink receptive material is applied to the web using a size press. 
     
     
         11 . A paper or paperboard product made by the method of  claim 1 . 
     
     
         12 . A paper or paperboard composite having enhanced long term storageability comprising:
 a base layer formed from a cellulosic fiber substrate, the base layer having a first surface, second surface and a basis weight ranging from about 80 to about 300 pounds per 3000 square feet,   a holdout layer adjacent the first surface of the base layer, and   an ink receptive layer adjacent the holdout layer, the ink receptive layer being selected from the group consisting of an aqueous acrylic polymer coating material, an aqueous fungicide and a combination of aqueous acrylic polymer coating material and aqueous fungicide.   
     
     
         13 . The composite of  claim 12  further comprising a printed image layer applied to the ink receptive layer. 
     
     
         14 . The composite of  claim 12  further comprising a printed image layer disposed between the holdout layer and the ink receptive layer. 
     
     
         15 . The composite of  claim 12  wherein the ink receptive layer comprises an aqueous, film forming acrylic polymer layer provided by a coating ink receptive coating material having a solids content ranging from about 30 to about 45 percent by weight. 
     
     
         16 . The composite of  claim 12  wherein the ink receptive layer comprises an aqueous biocidal agent. 
     
     
         17 . The composite of  claim 16  wherein the aqueous biocidal agent comprises 3-iodo-2-propynyl butyl carbamate. 
     
     
         18 . The composite of  claim 12  wherein the composite comprises a file folder. 
     
     
         19 . A method for reducing microbial growth on stored paper or paperboard products comprising providing a paper or paperboard product made from cellulosic fibers having a basis weight ranging from about 80 to about 300 pounds per 3000 square feet, applying from about 0.5 to about 1.5 percent by weight starch sizing agent to at least one surface of the paper or paperboard product to provide a sized web of paper or paperboard, coating the sized web with an aqueous biocidal agent and drying the web to provide a paper or paperboard product having reduced tendency for microbial growth. 
     
     
         20 . The method of  claim 19  wherein the aqueous biocidal agent comprises a latex coating material containing from about 15 to about 30 percent by weight active biocidal agent. 
     
     
         21 . The method of  claim 19  wherein both surfaces of the paper or paperboard product are coated with the starch sizing agent and aqueous biocidal agent. 
     
     
         22 . A method for improving the water-shedability of paper or paperboard products comprising providing a paper or paperboard web made from cellulosic fibers having a basis weight ranging from about 80 to about 300 pounds per 3000 square feet, applying from about 0.5 to about 1.5 percent by weight starch sizing agent to at least one surface of the paper or paperboard web to provide a sized web of paper or paperboard, coating the sized web with an ink receptive coating material to provide an ink receptive layer, and drying the coated and sized web at a first temperature to provide a paper or paperboard product having improved water-shedability, whereby the product exhibits a liquid resistance ranging from about 30 to about 40 grams per square meter water absorbance as measured by a Cobb Sizing test. 
     
     
         23 . The method of  claim 22  wherein the ink receptive layer comprises an aqueous acrylic polymer coating applied in an amount ranging from about 1.5 to about 3.0 pounds per 3000 square feet of paper or paperboard web. 
     
     
         24 . The method of  claim 22  further comprising wetting an uncoated side of the web with an aqueous fluid to reduce web curl, and drying the web at a second temperature. 
     
     
         25 . The method of  claim 22  wherein both surfaces of the web are coated with the sizing agent and ink receptive coating material. 
     
     
         26 . A file folder formed according to the method of  claim 22 .