Concentrated Dye Solution

Abstract

Concentrated aqueous dye solutions comprising one or more cationizable dyes, an organic acid and water and their use for dyeing and/or printing organic substrates and for producing inkjet printing inks.

1 . A concentrated aqueous dye solution comprising at least one cationizable dye, an organic acid and water, wherein the at least one cationizable dye is of the formula (I)  
       
         
           
           
               
               
           
         
       
       wherein 
 each A is independently —NH— or —O—,  
 B is a polyvalent group or atom,  
 n′ and n″ are natural numbers and the sum total of n′ and n″ is ≧2,  
 m is a natural number ≧0,  
 CC is a group having the formula (c 1 ) or (c 2 )  
                     
 wherein  
 each R 10  is independently H; C 1-4 alkyl; C 5-6 cycloalkyl; phenyl, benzyl or phenylethyl,  
 each R 10 ′ is independently H; —OH or C 1-4 alkyl  
 each T 1  is independently H; —CN; —COOR 15 ; CONR 16 R 17 ; SO 2 NR 16 R 17 ;  
                     
 G is H; —R 11 NHR 12  or —R 11 NR 13 R 14  where  
 R 11  is C 1-6 alkylene or C 2-6 alkenylene,  
 R 12 , R 13  and R 14  are independently H; unsubstituted C 1-6 alkyl; C 2-6 alkyl substituted by OH, CN or halogen; phenyl-C 1-3 alkyl where the phenyl radical is optionally singly, doubly or triply substituted by substituents selected from the group consisting of chlorine, C 1-4 alkyl and C 1-4 alkoxy; unsubstituted C 5-6 cycloalkyl or C 5-6 cycloalkyl singly, doubly or triply substituted by C 1-4 alkyl groups,  
 R 15  is C 1-6 alkyl radical or phenyl-C 1-3 alkyl radical,  
 R 16  and R 17  are independently H or a C 1-4 alkyl radical,  
 R 18  is independently H or a C 1-4 alkyl radical; —NR 16 R 17 —(CH 2 ) 2-4 —NR 16 R 17  or —CONR 16 R 17 ,  
 R 19  is a C 1-4 alkyl radical or a hydroxy-C 1-4 alkyl radical,  
 R 20  is —S— or —O—,  
 R 21  is a hydrogen atom or a C 1-4 alkyl radical, and  
 An −  is a non-coloured anion,  
 with the proviso that  
 (i) the sum total of n′, n″ and m is less than the number of valences of B,  
 (ii) when the sum total of n′ and n″=2, then m is ≧1,  
 (iii) when the sum total of n′ and n″=3 and A=NH, then m is ≧1.  
 
     
     
         2 . A concentrated aqueous dye solution according to  claim 1  wherein the at least one cationizable dye is at least one dye of the formula (II)  
       
         
           
           
               
               
           
         
       
       where B 1  and B 2  are independently —OH or NH 2  and D 3 =H or a residue of the formula  
       
         
           
           
               
               
           
         
       
       and 
 R 6 , R 7 , R 8  and R 9  are independently H or —SO 3 H and  
 M a  and M b  are independently M 1  to M 10 , wherein 
 M 1  is H.  
 M 2  is —(CH 2 ) 3 N(CH 3 ) 2 ,  
 M 3  is —(CH 2 ) 2 N(CH 2 CH 3 ) 2 ,  
 
 M 4  is  
                     
 M 5  is  
                     
 M 6  is  
                     
 M 7  is  
                     
 M 8  is  
                     
 M 9  is  
                     
 M 10  is —(CH 2 ) 2 NH 2 .  
 and  
 R a  or R b  are independently R 1  to R 5 , wherein  
 R 1  is H,  
                     
 R 2  is  
                     
 R 3  is  
 R 4  is CN,  
                     
 R 5  is  
 or at least one dye of the formula (III)  
                     
 Wherein  
 R 1 , R 2  or R 3  are independently H, CH 3 , C 2 H 5 , n-C 3 H 7 , i-C 3 H 7 , n-C 4 H 9 , i-C 4 H 9 , sec-C 4 H 9 ,  
 R n  is —C 2 H 4 —, —C 3 H 6 —, —CH(CH3)CH 2 — or —C 4 H 6 — 
 Y is hydrogen or nitro,  
 q is 1 or 2  
 and An −  is a non-coloured anion.  
 
     
     
         3 . A concentrated aqueous dye solution according to  claim 1  wherein the organic acid is an organic acid of the formula A′(—COOH) n , where A′ is C 1-12 -alkanyl or C 1-12 -alkenyl optionally interrupted by nitrogen atoms and/or oxygen atoms and optionally substituted by hydroxyl or NR′R″ (wherein R′ and R″ are independently C 1-6 -alkanyl or C 1-6 -alkenyl or C 1-6 -hydroxyalkanyl or C 1-6 -hydroxyalkenyl, or unsubstituted phenyl or hydroxyl- or sulphur- or C 1-18 -alkanyl- or C 1-18 -alkenyl-substituted phenyl and n is a natural number of 1, 2 or 3.  
     
     
         4 . A concentrated aqueous dye solution according to  claim 1  wherein the concentrated aqueous dye solution comprises up to 40% by weight of the at least one cationizable dye, from 0.5% to 25% by weight of the organic acid and is made up to 100% by weight with water.  
     
     
         5 . A process for producing a concentrated aqueous dye solution according to  claim 1 , comprising the step of pressing an aqueous solution or suspension of at least one crude cationic dye of the formula (I) through a semipermeable membrane by applying a pressure to remove salts, synthesis by-products having molecular weights below 500, and a portion of the water.  
     
     
         6 . A process for producing a concentrated aqueous dye solution according to  claim 5 , further comprising the step of continuously or intermittently replacing or supplementing the permeate with water or buffer solution so that the concentration of the at least one crude cationic dye in the permeate does not change by more than 20%.  
     
     
         7 . A process for dyeing and/or printing cellulosic material, comprising the step of contacting the at least one concentrated aqueous dye solution according to  claim 1  with the cellulosic material.  
     
     
         8 . A process for producing inks and formulations for contactless printing, comprising the step of combining at least one concentrated aqueous dye solution according to  claim 1 , with at least one additional chemical and/or water.  
     
     
         9 . A substrate that has been dyed or printed with a concentrated aqueous dye solution according to  claim 1 .  
     
     
         10 . A process according to  claim 7  wherein the cellulosic material is paper, board or card.  
     
     
         11 . A process according to  claim 8  wherein the contactless printing is inkjet printing.  
     
     
         12 . A substrate dyed and/or printed by a process in accordance with  claim 7 .  
     
     
         13 . An inkjet ink comprising the concentrated aqueous dye solution according to  claim 1.