Paper-making or non paper-making use of a starchy composition containing a selected cationic starchy material

Abstract

The invention concerns the use, as paper-making additive other than a standard mass additive or water treatment additive, of a starchy composition containing at least a cationic starch material. The invention is characterised in that said composition has: a fixed nitrogen proportion not more than 2%, preferably between 0.1 and 1.9%, said percentages being expressed in dry weight relative to the composition dry weight, and a viscosity, determined in accordance with a test A, of not more than 1600 mPa.s, preferably between 5 and 1500 mPa.s. Some of the starchy compositions, selected on the basis of their fixed nitrogen proportion and their viscosity, are also useful in numerous other fields of application, and in particular as mass additives in paper-making.

1 . The use, as paper-making additive other than a standard mass additive or as water treatment additive, of a starchy composition containing at least one cationic starchy material, characterized in that said composition has: 
 a fixed nitrogen level at most equal to 2%, preferably between 0.1 and 1.9%, these percentages being expressed by dry weight relative to the dry weight of the composition, and    a viscosity, determined according to a test A, at most equal to 1600 mPa.s, preferably between 5 and 1500 mPa.s.    
     
     
         2 . The use as claimed in  claim 1 , characterized in that the starchy composition has a fixed nitrogen level of between 0.2 and 1.5%.  
     
     
         3 . The use as claimed in either of claims  1  and  2 , characterized in that the cationic starchy material has a weight-average molecular mass of less than 10 7  daltons, preferably less than 5×10 6  daltons.  
     
     
         4 . The use as claimed in  claim 3 , characterized in that the cationic starchy material has a weight-average molecular mass of between 10 4  and 4×10 6  daltons.  
     
     
         5 . The use as claimed in any one of  claims 1  to  4 , characterized in that the starchy composition has a charge density index CDI greater than 600, preferably greater than 650.  
     
     
         6 . The use as claimed in  claim 5 , characterized in that the starchy composition has a CDI value of between 660 and 800.  
     
     
         7 . The use as claimed in any one of  claims 1  to  6 , characterized in that the starchy composition has a pH of less than 9, preferably of between 4 and 8.5.  
     
     
         8 . The use, as claimed in any one of  claims 1  to  7 , characterized in that the starchy composition has: 
 a fixed nitrogen level of between 0.4 and 1.5%, and  
 a viscosity, determined according to a test A, of between 10 and 800 mPa.s.  
 
     
     
         9 . The use as claimed in  claim 8 , characterized in that the starchy composition has: 
 a fixed nitrogen level of between 0.5 and 1.5%, and    a viscosity of between 50 and 700 mPa.s.    
     
     
         10 . The use as claimed in any one of  claims 1  to  9 , characterized in that the starchy composition has a dry matter content greater than 15% and less than 45%, preferably between 18 and 40%.  
     
     
         11 . The use of a cationic starchy material having a fixed nitrogen level at most equal to 2% and a weight-average molecular mass of less than 10 7  daltons for the preparation of a starchy composition used as claimed in any one of  claims 1  to  10 .  
     
     
         12 . The use as claimed in  claim 11 , characterized in that the cationic starchy material was obtained by treating a starchy material, before, during and/or after its cationization, preferably after its cationization, with at least one enzyme chosen from the group comprising branching enzymes (EC 2.4.1.18) and cyclodextrin glycosyltransferases (EC 2.4.1.19), which are thermostable or otherwise.  
     
     
         13 . The use of a starchy composition as claimed in any one of  claims 1  to  10  or prepared as claimed in either of claims  11  and  12 , as agent for reducing inconvenient substances contained in water circuits and/or retained on process equipment, for paper-making or otherwise, as additive in the preparation of sizing agent compositions used in paper-making, in particular as agent for protecting said agents, as additive in the preparation of compositions for creping, surfacing or coating paper, or as additive in the preparation of compositions containing optical brighteners, colorants and/or synthetic polymers, in particular polyacrylamides or polyvinylamines.  
     
     
         14 . A starchy composition containing at least one cationic starchy material characterized in that said composition has: 
 a fixed nitrogen level of between 0.5 and 1.5%, these percentages being expressed by dry weight relative to the dry weight of the composition, and    a viscosity, determined according to a test A, of between 10 and 800 mPa.s.    
     
     
         15 . The starchy composition as claimed in  claim 14 , characterized in that it has: 
 a fixed nitrogen level of between 0.6 and 1.5%, and    a viscosity of between 50 and 700 mPa.s.    
     
     
         16 . The starchy composition as claimed in either of claims  14  and  15 , characterized in that it has: 
 a pH of less than 9, preferably of between 4 and 8.5, and  
 a charge density index CDI greater than 600.  
 
     
     
         17 . The use of a composition as claimed in any one of  claims 14  to  16 , as paper-making additive or as industrial water treatment additive.  
     
     
         18 . The use as claimed in  claim 17 , characterized in that the starchy composition is combined, simultaneously or otherwise, with at least one other active material, preferably chosen from sizing agents, optical brighteners, colorants and synthetic polymers, in particular polyacrylamides or polyvinylamines.  
     
     
         19 . The use as claimed in  claim 18 , characterized in that the weight ratio synthetic polymer(s)/cationic starchy material(s) is between 1/100 and 100/1, said ratios being expressed as dry weights of synthetic polymer(s) on the one hand and of cationic starchy material(s) on the other hand.