Surface finishing 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 .- 11 . (canceled)  
     
     
         12 . A process for the production of surface-finished paper or board (B w ), said process comprising the steps of applying to a surface of a hydrophilic paper or board sheet (B) an aqueous solution (L w ) consisting of water and a surface-finishing active ingredient (W) and optionally a non-finishing formulation additive (F), in which the surface-finishing active ingredient (W) consists of 
 (W 1 ) polyethylene glycol with an average molecular weight {overscore (M)} w  of >1500, or of (W 1 ) and at least one further additive selected from the group consisting of 
 (W 2 ) at least one dye and/or optical brightener,  
 (w 3 ) a wet strength additive selected from the group consisting of products of the reaction of aldehydes with nitrogen compounds containing amidic NH 2  groups, if desired in combination with suitable catalysts (W 3 ″), and products of the reaction of epichlorohydrin with aliphatic mono- or oligoamines, which are optionally quaternized,  
 (W 4 ) at least one agent for pH adjustment  
 and mixtures thereof,  
   and the non-finishing formulation additive (F) is selected from the group consisting of 
 (F 11 ) antifoams,  
 (F 12 ) agents for protecting against the damaging effect of micro-organisms  
 and mixtures thereof,  
 and smoothing and drying said surface-treated paper or board sheet through smoothing rolls:  
   
     
     
         13 . A process according to  claim 12 , wherein (W) consists of polyethylene glycol (W 1 ) or of polyethylene glycol (W 1 ) and wet strength additive (W 3 ).  
     
     
         14 . A process according to  claim 12 , wherein (W) consists of polyethylene glycol (W 1 ), at least one of additives (W 2 ) and (W 3 ), and optionally additive (W 4 ).  
     
     
         15 . A process according to  claim 12 , wherein (W) comprises at least one dye and/or optical brightener (W 2 ) and the average molecular weight {overscore (M)} w  of polyethylene glycol (W 1 ) is in the range of 1600 to 4000.  
     
     
         16 . A process according to  claim 12 , wherein (L w ) consists of water, polyethylene glycol (W 1 ) and at least one of additives (W 3 ) and (F).  
     
     
         17 . A process according to  claim 12 , wherein (W) comprises a wet strength additive (W 3 ).  
     
     
         18 . A process according to  claim 17 , wherein the average molecular weight {overscore (M)} w  of polyethylene glycol (W 1 ) is in the range of 2000 to 20,000.  
     
     
         19 . A process according to  claim 12 , wherein (W) consists of polyethylene glycol (W 1 ) and wet strength additive (W 3 ).  
     
     
         20 . A process according to  claim 12 , wherein (W 3 ) is (W 3 ′) a crosslinkable product which is reactive with aliphatic hydroxyl groups  
     
     
         21 . A process according to  claim 20 , wherein (W 3 ′) is selected from the group consisting of products of the reaction of aldehydes with nitrogen compounds containing amidic NH 2  groups, if desired in combination with suitable catalysts (W 3 ″), and products of the reaction of epichlorohydrin with aliphatic mono- or oligoamines, which are optionally quaternized.  
     
     
         22 . A process according to  claim 21 , wherein (W 3 ′) is selected from the group consisting of products of the reaction of formaldehyde or glyoxal with urea or melamines, and products of the reaction of epichlorohydrin with aliphatic mono- or oligoamines with 2 to 6 carbon atoms, which are optionally quaternized.  
     
     
         23 . A process according to  claim 12 , wherein (W) consists of at least 30% by weight of polyethylene glycol (W 1 )  
     
     
         24 . A process according to  claim 12 , wherein said aqueous solution (L w ) contains at least one non-finishing formulation additive (F).  
     
     
         25 . A process according to  claim 12 , wherein said aqueous solution (L w ) essentially consists of (W) and water.  
     
     
         26 . Process according to  claim 12 , wherein said applying step comprises spraying said aqueous solution (L w ) on a surface of said hydrophilic paper or board sheet (B).  
     
     
         27 . A process according to  claim 12 , wherein said smoothing through smoothing rolls comprises smoothing through smoothing rolls at a smoothing pressure in the range of 8 to 500 KN/m  
     
     
         28 . Process according to  claim 12 , wherein said smoothing rolls are calendering rolls.  
     
     
         29 . A process for the production of surface finished paper or board (B w ), said process comprising the steps of: 
 a) forming a paper web (B) from an aqueous pulp suspension and transporting the paper web to a press section to remove a portion of the water from the paper web to provide a hydrophilic paper or board sheet having a moisture content ≦30% by weight    b) applying to a surface of the hydrophilic paper or board sheet (B) an aqueous solution (L w ) consisting of water and a surface-finishing active ingredient (W) and optionally a non-finishing formulation additive (F), in which the surface-finishing active ingredient (W) consists of 
 (W 1 ) polyethylene glycol with an average molecular weight {overscore (M)}w of >1500,  
 or of (W 1 ) and at least one further additive selected from the group consisting of 
 (W 2 ) at least one dye and/or optical brightener,  
 (W 3 ) a wet strength additive selected from the group consisting of products of the reaction of aldehydes with nitrogen compounds containing amidic NH 2  groups, if desired in combination with suitable catalysts (W 3 ″), and products of the reaction of epichlorohydrin with aliphatic mono- or oligoamines, which are optionally quaternized.  
 (W 4 ) at least one agent for pH adjustment  
 and mixtures thereof,  
 
 and the non-finishing formulation additive (F) is selected from the group consisting of 
 (F 11 ) antifoams,  
 (F 12 ) agents for protecting against the damaging effect of micro-organisms  
 and mixtures thereof,  
 
   c) passing the surface-treated paper or board sheet to a smoothing roll zone and therein subjecting the surface-treated paper or board to pressure and drying to provide the surface-finished paper or board sheet.    
     
     
         30 . A process for the production of surface finished paper or board (B w ), said process comprising the steps of 
 a) passing a hydrophilic paper or board sheet to a re-wetting zone and therein moistening the hydrophilic paper or board sheet to a moisture content in the range of 4 to 16% by weight to provide a re-moistened paper,    b) applying uniformly to a surface of the re-moistened sheet an aqueous solution (L w ) consisting of water and a surface-finishing active ingredient (W) and optionally a non-finishing formulation additive (F), in which the surface-finishing active ingredient (W) consists of 
 (W 1 ) polyethylene glycol with an average molecular weight {overscore (M)}w of >1500,  
 or of (W 1 ) and at least one further additive selected from the group consisting of 
 (W 2 ) at least one dye and/or optical brightener,  
 (W 3 ) a wet strength additive selected from the group consisting of products of the reaction of aldehydes with nitrogen compounds containing amidic NH 2  groups, if desired in combination with suitable catalysts (W 3 ″), and products of the reaction of epichlorohydrin with aliphatic mono- or oligoamines, which are optionally quaternized.  
 (W 4 ) at least one agent for pH adjustment  
 and mixtures thereof,  
 
 and the non-finishing formulation additive (F) is selected from the group consisting of 
 (F 11 ) antifoams,  
 (F 12 ) agents for protecting against the damaging effect of micro-organisms  
 and mixtures thereof,  
 
   c) passing the surface-treated paper or board sheet to a calendering zone and therein subjecting the surface-treated paper or board to calender pressure and drying to provide the surface-finished paper or board sheet.    
     
     
         31 . A process for the production of surface finished paper or board (B w ), said process comprising the steps of: 
 a) passing a hydrophilic paper or board sheet to a re-wetting zone and therein moistening the hydrophilic paper or board sheet with an aqueous solution (L w ) consisting of water and a surface-finishing active ingredient (W) and optionally a non-finishing formulation additive (F), in which the surface-finishing active ingredient (W) consists of 
 (W 1 ) polyethylene glycol with an average molecular weight {overscore (M)}w of >1500,  
 or of (W 1 ) and at least one further additive selected from the group consisting of 
 (W 2 ) at least one dye and/or optical brightener,  
 (W 3 ) a wet strength additive selected from the group consisting of products of the reaction of aldehydes with nitrogen compounds containing amidic NH 2  groups, if desired in combination with suitable catalysts (W 3 ″), and products of the reaction of epichlorohydrin with aliphatic mono- or oligoamines, which are optionally quaternized.  
 (W 4 ) at least one agent for pH adjustment  
 and mixtures thereof,  
 
 and the non-finishing formulation additive (F) is selected from the group consisting of 
 (F 11 ) antifoams,  
 (F 12 ) agents for protecting against the damaging effect of micro-organisms  
 and mixtures thereof,  
 
   to a moisture content in the range of 4 to 16% by weight to provide a re-moistened paper,    b) passing the surface-treated paper or board sheet to a calendering zone and therein subjecting the surface-treated paper or board to calender pressure and drying to provide the surface-finished paper or board sheet.    
     
     
         32 . A process according to  claim 31 , wherein the re-moisturising solution comprises 0.01 to 10% by weight of (W).  
     
     
         33 . Paper or board (B w ) surface-finished in accordance with the process of  claim 12 .  
     
     
         34 . Paper or board (B w ) according to  claim 22  which is essentially size-free and is intaglio printing and offset printing paper or board.  
     
     
         35 . 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, wherein the substrate used for this purpose is surface-finished paper (B w ) or surface-finished board (B w ) according to  claim 22.