Surface finshing of paper or board, and agent for this purpose

Abstract

Surface finishing of paper or board by applying an aqueous solution (L w ) of a surface-finishing active ingredient (W) to a hydrophilic paper or board sheet (B), in which (W) consists of (W 1 ) polyethylene glycol with an average molecular weight {overscore (M)}w of >1500 and optionally at least one further additive which is a further finishing additive and/or a formulation additive, and the paper or board sheet surface-treated with (L w ) is fed through smoothing rolls and dried, the surface-finished paper and surface-finished board (B w ) produced, surface finishing agent for this purpose, and the use of the surface-finished paper or board as substrate for graphic processing.

1 . Process for the production of surface-finished paper or board (B w ), characterized in that an aqueous solution (L w ) of a surface-finishing active ingredient (W) is applied to a hydrophilic paper or board sheet (B),  
       in which (W) consists of 
 (W 1 ) polyethylene glycol with an average molecular weight {overscore (M)}w of >1500  
 and optionally at least one further additive which is a further finishing additive and/or a formulation additive,  
 and the paper or board sheet surface-treated with (L w ) is fed through smoothing rolls and dried.  
 
     
     
         2 . Process according to  claim 1 , characterized in that (W) consists of at least 30% by weight of (W 1 ) and any remainder to 100% by weight of at least one further of the finishing additives (W 2 ) and (W 3 ) and/or formulation additives (W 4 ), in which 
 (W 2 ) is at least one dye and/or optical brightener,    (W 3 ) is at least one wet strength additive    and    (W 4 ) is at least one agent for pH adjustment.    
     
     
         3 . Process according to  claim 1  or  2 , characterized in that (W) contains at least one non-finishing formulation additive (F).  
     
     
         4 . Process according to one of  claims 1  to  3 , characterized in that (L w ) essentially consists of (W) and water.  
     
     
         5 . Process according to one of  claims 1  to  4 , at a line pressure of the smoothing rolls in the range of 8 to 500 KN/m.  
     
     
         6 . Process according to one of  claims 1  to  5 , characterized in that the paper or board sheet surface-treated with (L w ) is calendered.  
     
     
         7 . Surface finishing agent for paper or board which is a solution (L w ) as defined in  claim 4 , wherein (F) is selected from, 
 (F 11 ) antifoams    and    F( 12 ) agents for protecting against the damaging effect of microorganisms.    and with a (W 1 )-content in the range of 0.1 to 20 %.    
     
     
         8 . Surface finishing agent according to  claim 7  which is an antiyellowing agent for paper or board.  
     
     
         9 . Paper or board (B w ) surface-finished in accordance with any one of  claims 1  to  6 .  
     
     
         10 . Paper or board (B w ) according to  claim 9  which is essentially size-free and is simultaneously intaglio printing and offset printing paper or board.  
     
     
         11 . Process for the production of graphically processed paper or board by application of at least one graphic ink pattern to a substrate of paper or board, and drying, characterized in that the substrate used for this purpose is surface-finished paper (B w ) or surface-finished board (B w ) according to  claim 8  or  9 .