Composition for the fluorescent whitening of paper

Abstract

A composition comprising a) 5 to 25% by weight of a fluorescent whitening agent of the formula (1), wherein R 1 and R 2 independently represent C 1 -C 4 alkyl, C 2 -C 4 hydroxyalkyl or together complete a morpholine ring and M is an alkaline or alkaline earth metal, b) 0.5 to 5% by weight of a swellable layered silicate which is hectorite and/or vermiculite, c) water and, optionally, d) further adjuvants and the use thereof for the fluorescent whitening of paper in the pulp mass, in coatings or in the size press or metering size press.

1 . A composition comprising 
 a) 5 to 25% by weight of a fluorescent whitening agent of the formula                           wherein    R 1  and R 2  independently represent C 1 -C 4 alkyl, C 2 -C 4 hydroxyalkyl or together complete a morpholine ring and    M is an alkaline or alkaline earth metal,    b) 0.5 to 5% by weight of a swellable layered silicate which is hectorite and/or vermiculite,    c) water and, optionally,    d) further adjuvants.    
     
     
         2 . A composition according to  claim 1  comprising 10 to 20% by weight of the fluorescent whitening agent of formula (1).  
     
     
         3 . A composition according to claims  1  or  2  comprising 0.5 to 3% by weight of hectorite.  
     
     
         4 . A composition according to  claim 3  comprising 0.5 to 1.5% by weight of hectorite.  
     
     
         5 . A composition according to claims  1  or  2  comprising 0.5 to 5% by weight of vermiculite.  
     
     
         6 . A composition according to  claim 5  comprising 0.5 to 1.5% by weight of vermiculite.  
     
     
         7 . A composition according to any one of  claims 1  to  6 , wherein, In the fluorescent whitening agent of formula (1), 
 R 1  represents methyl, ethyl, hydroxyethyl or hydroxypropyl,  
 R 2  represents hydroxyethyl or hydroxypropyl or  
 R 1  and R 2  together complete a morpholine ring and  
 M represents lithium, potassium or sodium  
 
     
     
         8 . A composition according to  claim 7  wherein the fluorescent whitening agent is selected from the compounds of formulae  
       
         
           
           
               
               
           
         
       
     
     
         9 . Use of the composition according to any one of  claims 1  to  8  for the fluorescent whitening of paper.  
     
     
         10 . Use according to  claim 9 , whereby the composition is added to the pulp mass.  
     
     
         11 . Use according to  claim 9 , whereby the composition is used for paper coating.  
     
     
         12 . Use according to  claim 9 , whereby the composition is added to the size press or metering size press.  
     
     
         13 . Paper, which has been optically brightened by the method according to  claims 9  to  12 .