Patterned paper

Abstract

The present invention relates to a process for the production of nonuniformly intensely colored paper, and paper produced by this process. The process comprises: (a) application of at least one surfactant or a mixture of surfactants in the forms of a latent image or pattern to paper, (b) coloring of the paper by means of a dye solution and (c) drying of the colored paper.

1 . A process for the production of nonuniformly intensely colored paper, comprising 
 a) application of at least one surfactant or a mixture of surfactants in the form of a latent image or pattern to paper,    b) coloring of the paper by means of a dye solution and    c) drying of the colored paper.    
     
     
         2 . The process as claimed in  claim 1 , wherein the latent image or pattern is produced by applying the surfactant (mixture) by means of inkjet printing, offset printing, flexographic printing, gravure printing or printing by means of felt or rubber rollers, by spraying on or manually.  
     
     
         3 . The process as claimed in  claim 1  or  2 , wherein the applied surfactant facilitates the penetration of water-soluble dyes into the paper.  
     
     
         4 . The process as claimed in  claim 1  or  2 , wherein the applied surfactant reduces the penetration of water-soluble dyes into the paper.  
     
     
         5 . The process as claimed in any of  claims 1  to  4 , wherein, in step a), both a surfactant which facilitates the penetration of water-soluble dyes into the paper and a surfactant which reduces the penetration of water-soluble dyes into the paper are applied.  
     
     
         6 . The process as claimed in any of  claims 1  to  5 , wherein, in step a), the application is effected on a continuous paper web.  
     
     
         7 . The process as claimed in any of  claims 1  to  6 , wherein an aqueous dye solution is used in step b).  
     
     
         8 . The process as claimed in  claim 7 , wherein the coloring in step b) is carried out inside or outside the paper machine by applying dye solution(s) to the paper by means of classical paper coating apparatuses and methods, such as a size press, film press, knife coater, blade, rolls or spraying or by application of a dye solution to the total surface of the paper with the aid of suitable printing methods, such as inkjet printing, offset printing, flexographic printing, gravure printing or printing by means of felt or rubber rollers, or by spraying on or by tub coloring.  
     
     
         9 . The process as claimed in any of  claims 1  to  8 , wherein the image or pattern is a diagram, a signet, a regular or irregular pattern, a net structure or any desired nonuniform color distribution.  
     
     
         10 . A paper obtainable by one of the processes as claimed in any of  claims 1  to  9 .