Printing papers

Abstract

Printing papers with reduced discoloration are obtained by using a pulp with improved discoloration. Printing papers with remarkably improved discoloration can be obtained by including a pulp consisting of one member or a mixed pulp of two or more members of bleached or unbleached mechanical pulps, semichemical pulps, chemical pulps and deinked pulps irradiated with UV and/or visible light in the presence of at least one additive selected from the group consisting of reducing agents, oxidizing agents and hydrogen-donating organic compounds.

1 . A printing paper containing a pulp irradiated with UV and/or visible light in the presence of at least one compound selected from the group consisting of reducing agents, oxidizing agents and hydrogen-donating organic compounds.  
   
   
       2 . A printing paper irradiated with UV and/or visible light in the presence of at least one compound selected from the group consisting of reducing agents, oxidizing agents and hydrogen-donating organic compounds.  
   
   
       3 . The printing paper of  claim 1  containing a pulp irradiated with UV and/or visible light using sodium borohydride or tetrabutylammonium borohydride or a mixture thereof as a reducing agent.  
   
   
       4 . The printing paper of  claim 2  irradiated with UV and/or visible light using sodium borohydride or tetrabutylammonium borohydride or a mixture thereof as a reducing agent.