Abstract:
The invention relates to dissolving an anionic dye/cationic polymer complex comprising the step of applying to the complex a water-soluble solvent having a dielectric constant from 20 to 43 at standard temperature and pressure.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a divisional of co-pending U.S. patent application Ser. No. 11/256,136, filed on Oct. 21, 2005, currently pending, which itself is a divisional of U.S. patent application Ser. No. 10/354,624, filed on Jan. 28, 2003, now U.S. Pat. No. 6,998,429, which is assigned to the assignee of the present patent application and which is incorporated by reference in its entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    In inkjet printing, anionic dye and cationic polymer fixer are often used. Together they form a complex that sometimes must be dissolved and removed from places where it has formed, such as the printhead. 
       BACKGROUND OF THE INVENTION 
       [0003]    Dye-based inkjet inks have become a dominant technology in the inkjet ink arena. However, as many dyes are water-soluble, images printed using many of such dye-based inkjet inks are not as waterfast as may be desirable. The waterfastness and durability of anionic dye-based inkjet ink printed on media has been shown to be enhanced by overprinting or underprinting the printed image with a fixer, preferably from a separate pen. Fixers work to crash the colorants, e.g. anionic dyes, anionic pigments or carboxylated dyes, by changing the pH of the printed inkjet image or by adding salts such as Ca 2+  and Mg 2+  to the printed inkjet image. These fixers had the disadvantages of lacking durability, of causing pen wear and tear and corrosion due to the high salt content and the low pH. 
         [0004]    More recently, cationic polymers have been used in the fixer. Thus, when the cationic polymer and the anionic dye contact one another on a substrate, a reaction between the dye and the polymer creates an image with improved durability and waterfastness. Inkjet images with improved waterfastness and durability can therefore be obtained by underprinting or overprinting a printed inkjet image with a cationic polymeric fixer. 
         [0005]    Thus, anionic inks can be rendered more durable by printing with a fluid containing a cationic polymer. Sometimes during printing, the ink and the polymer fluids come into contact on the surface of one of the printheads, creating a durable complex which is difficult to remove with such servicing fluids as 1,2 hexanediol, glycerol and water. 
       SUMMARY OF THE INVENTION 
       [0006]    The present invention relates to a method of dissolving an anionic dye/cationic polymer complex comprising the step of applying to the complex a water-soluble solvent having a dielectric constant from 20 to 43 at standard temperature and pressure. 
         [0007]    The present invention additionally relates to an inkjet printhead cleaning system, wherein an anionic dye/cationic polymer complex on the printhead is removed by applying to the complex on the printhead a water-soluble solvent having a dielectric constant from 20 to 43 at standard temperature and pressure. 
         [0008]    Also, the present invention relates to a method of removing an anionic dye/cationic polymer complex from an inkjet printhead, comprising the step of applying to the complex on the printhead a water-soluble solvent having a dielectric constant from 20 to 43 at standard temperature and pressure. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    For a detailed description of embodiments of the invention, reference will now be made to the accompanying drawings in which: 
           [0010]      FIGS. 1A and 1B  plot the Fixer/Dye ratio against the % Colorant Soluble for complexes of anionic dyes with cationic fixers in deionized (DI) water. 
           [0011]      FIGS. 2A and 2B  plot the Fixer/Dye ratio against the % Colorant Soluble for complexes of anionic dyes with cationic fixers in 8% 2P. 
           [0012]      FIGS. 3A and 3B  plot the Fixer/Dye ratio against the % Colorant Soluble for complexes of anionic dyes with cationic fixers in 40% 2P. 
           [0013]      FIGS. 4A and 4B  plot the %2P against the % Colorant Soluble with the Fixer/Dye Weight Ratio equal to 1/1. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    In order to obtain images that are durable to highlighter smear or water drip and smudge, inks containing anionic dyes are underprinted and/or overprinted with fluids containing cationic polymers. The dye/polymer complex forms a durable mixture. When the ink and the polymer fluid end up on a printhead surface, the mixture is not easily removed by typical water-soluble servicing solvents such as 1,2-hexane diol, glycerol and water. 
       Effective and Ineffective Water Soluble Solvents 
       [0015]    To study which water-soluble servicing solvents are best for removing the ink/polymer complex, the solubility of the precipitate formed between dye and fixers was evaluated in a variety of solvents. Specifically inks and fixers were pipetted onto cellulose TLC plates, dried and developed in a variety of solvents as described in Examples 1 and 2. 
         [0016]    As shown in the Examples below, it was found that the dye/fixer complex precipitate is immobile in water, dipropylene glycol, 1,2 hexanediol, and 1,6-hexanediol indicating a lack of solubility in these solvents. In 2-amino-2-methyl propanol and 1,2 propanediol, it was found that some, but not all, of the complex precipitates are mobile, indicating that at least some of the complex precipitates are soluble in these solvents. 
         [0017]    Also in the Examples, it is seen that all of the complex precipitates are mobile and therefore solubilized in 2-pyrrolidone, diethylene glycol, 1,2-propanediol, tetraethylene glycol, 1-methyl-2-pyrrolidone and n,n-dimethyl propionamide. 
         [0018]    It has been found that 2-pyrrolidone is very effective at dissolving the dye-polymer complex. Furthermore, mixtures of 2-pyrrolidone and water are capable of dissolving the complex and are compatible with the printhead materials. The weight percentage ratio of 2-pyrrolidone to water can be from 100:0 to 20:80. In a preferred embodiment, the weight percentage ratio is 40:60. 
         [0019]    It has also been found that 2-pyrrolidone inhibits precipitation of the anionic dye/cationic polymeric fixer complex as manifested by a greater equilibrium solubility and a slower precipitation rate. No precipitation was observed in systems containing less than 45 weight % 2-pyrrolidone. 
         [0020]    Dielectric constants at standard temperature and pressure for most of the water-soluble servicing solvents tested have been obtained at standard temperature and pressure. Generally, it has been found that solvents that are “effective” at solubilizing anionic dye/cationic fixer complexes have dielectric constants that fall within the range of from approximately 20 to approximately 43 at standard temperature and pressure. In contrast, it has been found that solvents that are “ineffective” at solubilizing anionic dye/cationic fixer complexes have dielectric constants that fall outside the above range of 20-43 at standard temperature and pressure. Comparative tables are shown below: 
         [0000]    
       
         
               
               
             
               
               
               
             
           
               
                   
                   
               
               
                   
                 Dielectric Constants at STP 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 “Effective” Solvents 
                   
               
               
                   
                 2-pyrrolidone 
                 28.18 
               
               
                   
                 Diethylene glycol 
                 31.82 
               
               
                   
                 1,2-propanediol 
                 32 
               
               
                   
                 Tetraethylene glycol 
                 20.44 
               
               
                   
                 1-methyl-2-pyrrolidone 
                 32.2 
               
               
                   
                 N,n-dimethylpropionamide 
                 34.6 
               
               
                   
                 Triethylene glycol 
                 23.7 
               
               
                   
                 1,5-pentanediol 
                 26.2 
               
               
                   
                 1,4-pentanediol 
                 31.9 
               
               
                   
                 “Ineffective” Solvents 
               
               
                   
                 Water 
                 78 
               
               
                   
                 Cyclohexanone 
                 16.1 
               
               
                   
                 Butoxyethanol 
                 9.43 
               
               
                   
                 Diacetone alcohol 
                 18.2 
               
               
                   
                 1-pentanol 
                 16.9 
               
               
                   
                 1,2-pentanediol 
                 17.3 
               
               
                   
                 Glycerol 
                 46.5 
               
               
                   
                   
               
             
          
         
       
     
       Anionic Dyes Forming a Complex with Fixer 
       [0021]    Non-limiting examples of anionic dyes that are effective with this invention are: direct black dyes, such as Direct Black 168 (DB168), Direct Black 19 (DB19) or variants of Fast Black 2; phthalocyanine cyan dyes, such as ProJet Cyan 485; acid cyan dyes, such as Acid Blue 9 (AB9); mixtures of acid cyan and phthalocyanine cyan, such as AB9 and ProJet Cyan 485 (PJ485); gamma acid magenta dyes, such as Magenta 377 (M377); H-acid magenta dyes, such as ProJet Magenta 364 (M364); Xanthene magenta dyes, such as Acid Red 289 (AR289); mixtures of H-acid magenta and Xanthene magenta dyes, such as mixtures of ProJet Magenta 364 and AR289; direct yellow dyes, such as Direct Yellow 132 (DY132); acid yellow dyes such as Acid Yellow 23 (AY23); and mixtures of direct yellow dyes and acid yellow dyes, such as mixtures of DY132 and AY23. 
       Cationic Polymeric Fixers Forming a Complex with Anionic Dyes 
       [0022]    In a preferred embodiment of the fixer, polyguanidines and polyethyleneimines, have been found to be effective cationic polymers for this purpose. 
         [0023]    In a more preferred embodiment, the cationic polymers are polymonoguanidines, preferably poly (C 3-18 -hydrocarbyl monoguanidines). 
         [0024]    In a most preferred embodiment, the poly(C 3-18 -hydrocarbyl monoguanidines) comprise groups selected from the group consisting of Formula (1) and Formula (2) or salts thereof: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein: 
         [0025]    each m is independently 0 or 1; 
         [0026]    each Y is independently a C 2-18 -hydrocarbyl group; 
         [0027]    A and B are hydrocarbyl groups which together comprise a total of 3 to 18 carbon atoms; and 
         [0000]    each R is independently hydrogen, alkyl, alkoxy, substituted alkyl or substituted alkoxy. 
         [0028]    In another most preferred embodiment, the poly(C 3-18 -hydrocarbyl monoguanidines) comprise at least one group of Formula (3) or salts thereof: 
         [0000]    
       
                 
         
             
             
         
       
     
         [0000]    wherein: 
         [0029]    n is from 2 to 50. 
       EXAMPLES 
     Example 1 
       [0030]    For each of Runs 1, 2 and 3, 1 microliter anionic dye-based ink and cationic polymeric fixer is pipetted in the order Fixer/Color/Fixer for each of colors black, cyan, magenta and yellow onto cellulose thin layer chromatography (TLC) plates. The three TLC plates were dried for 30 minutes at ambient temperature. The TLC plates were developed in solvent at 55° C. 
         [0031]    The table below summarizes the mobility of Run 1, Run 2, and Run 3 dye/fixer complex/precipitates in various water-based servicing solvents. 
         [0000]    
       
         
               
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 1 
               
               
                   
               
               
                 Run/ 
                   
                   
                 Dipropylene 
                 1,2 
                   
                 Tetraethyl- 
                 Diethylene 
                 2-pyrroli- 
               
               
                 Ink 
                 Dye 
                 Fixer 
                 glycol 
                 Hexanediol 
                 Water 
                 ene glycol 
                 glycol 
                 done 
               
               
                   
               
             
             
               
                 Run 
                 Direct Black 
                 Poly-alkyl 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
                 Slight 
                 Moderate 
               
               
                 1/K 
                   
                 amine 
               
               
                 Run 
                 Phthalo- 
                 Poly-alkyl 
                 Immobile 
                 Immobile 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
               
               
                 1/C 
                 cyanine cyan 
                 amine 
               
               
                 Run 
                 Gamma acid 
                 Poly-alkyl 
                 Immobile 
                 Immobile 
                 Immobile 
                 Immobile 
                 Immobile 
                 Completely 
               
               
                 1/M 
                 magenta 
                 amine 
               
               
                 Run 
                 Direct yellow 
                 Poly-alkyl 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
                 Moderate 
                 Completely 
               
               
                 1/Y 
                   
                 amine 
               
               
                 Run 
                 Direct Black 
                 Poly- 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
                 Slight 
                 Moderate 
               
               
                 2/K 
                 (different from 
                 guanidine 
               
               
                   
                 1/K) 
               
               
                 Run 
                 Phthalo- 
                 Poly- 
                 Immobile 
                 Immobile 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
               
               
                 2/C 
                 cyanine cyan 
                 guanidine 
               
               
                 Run 
                 H-acid 
                 Poly- 
                 Immobile 
                 Immobile 
                 Very 
                 Slight 
                 Moderate 
                 Moderate 
               
               
                 2/M 
                 magenta 
                 guanidine 
                   
                   
                 slight 
               
               
                 Run 
                 Direct yellow 
                 Poly- 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
                 Moderate 
                 Completely 
               
               
                 2/Y 
                   
                 guanidine 
               
               
                 Run 
                 Direct Black 
                 Poly- 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
                 Slight 
                 Moderate 
               
               
                 3/K 
                 (different from 
                 guanidine 
               
               
                   
                 1/K) 
               
               
                 Run 
                 Mixture of acid 
                 Poly- 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
                 Slight 
                 Moderate 
               
               
                 3/C 
                 cyan and 
                 guanidine 
               
               
                   
                 phthalo- 
               
               
                   
                 cyanine cyan 
               
               
                 Run 
                 Mixture of H- 
                 Poly- 
                 Very 
                 Very 
                 Very 
                 Slight 
                 Moderate 
                 Moderate 
               
               
                 3/M 
                 acid magenta 
                 guanidine 
                 slight 
                 slight 
                 slight 
               
               
                   
                 and xanthene 
               
               
                   
                 magenta 
               
               
                 Run 
                 Mixture of 
                 Poly- 
                 Immobile 
                 Immobile 
                 Very 
                 Slight 
                 Moderate 
                 Completely 
               
               
                 3/Y 
                 direct yellow 
                 guanidine 
                   
                   
                 slight 
               
               
                   
                 and acid 
               
               
                   
                 yellow 
               
               
                   
               
             
          
         
       
     
       Example 2 
       [0032]    For each of Runs 4, 5 and 6, 1 microliter anionic dye-based ink and cationic polymeric fixer is pipetted in the order Fixer/Color/Fixer for each of colors black, cyan, magenta and yellow onto cellulose TLC plates. The three TLC plates were dried for 30 minutes at ambient temperature. The TLC plates were developed in various water-based servicing solvent at 55° C. 
         [0033]    The table below summarizes the mobility of Run 3, Run 4, and Run 5 dye/fixer complex/precipitates in the various solvents. 
         [0000]    
       
         
               
               
               
               
               
               
               
               
             
           
               
                 TABLE 2 
               
               
                   
               
               
                   
                   
                   
                   
                   
                   
                 2-amino-2- 
                   
               
               
                   
                   
                   
                   
                   
                   
                 methyl 
                 1,2- 
               
               
                 Fixer/ 
                   
                   
                 Cyclohexa- 
                 Butoxy- 
                 Diacetone 
                 propanol 
                 propane- 
               
               
                 Ink 
                 Dye 
                 Fixer 
                 none 
                 ethanol 
                 alcohol 
                 (AMP) 
                 diol 
               
               
                   
               
             
             
               
                 Run 
                 Direct Black 
                 Polyalkyl 
                 Immobile 
                 Immobile 
                 Immobile 
                 Moderate 
                 Slight 
               
               
                 4/K 
                   
                 amine 
               
               
                 Run 
                 Phthalo- 
                 Polyalkyl 
                 Immobile 
                 Immobile 
                 Immobile 
                 Completely 
                 Immobile 
               
               
                 4/C 
                 cyanine cyan 
                 amine 
               
               
                 Run 
                 Gamma acid 
                 Polyalkyl 
                 Immobile 
                 Immobile 
                 Immobile 
                 Moderate 
                 Very 
               
               
                 4/M 
                 magenta 
                 amine 
                   
                   
                   
                   
                 slight 
               
               
                 Run 
                 Direct yellow 
                 Polyalkyl 
                 Immobile 
                 Immobile 
                 Immobile 
                 Completely 
                 Slight 
               
               
                 4/Y 
                   
                 amine 
               
               
                 Run 
                 Direct Black 
                 Poly- 
                 Immobile 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
               
               
                 5/K 
                 (different from 
                 guanidine 
               
               
                   
                 1/K) 
               
               
                 Run 
                 Phthalo- 
                 Poly- 
                 Immobile 
                 Immobile 
                 Immobile 
                 Immobile 
                 Very 
               
               
                 5/C 
                 cyanine cyan 
                 guanidine 
                   
                   
                   
                   
                 slight 
               
               
                 Run 
                 H-acid 
                 Poly- 
                 Immobile 
                 Immobile 
                 Immobile 
                 Immobile 
                 Moderate 
               
               
                 5/M 
                 magenta 
                 guanidine 
               
               
                 Run 
                 Direct yellow 
                 Poly- 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
                 Moderate 
               
               
                 5/Y 
                   
                 guanidine 
               
               
                 Run 
                 Direct Black 
                 Poly- 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
                 Slight 
               
               
                 6/K 
                 (different from 
                 guanidine 
               
               
                   
                 1/K) 
               
               
                 Run 
                 Mixture of acid 
                 Poly- 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
                 Moderate 
               
               
                 6/C 
                 cyan and 
                 guanidine 
               
               
                   
                 phthalo- 
               
               
                   
                 cyanine cyan 
               
               
                 Run 
                 Mixture of H- 
                 Poly- 
                 Very 
                 Very 
                 Very 
                 Slight 
                 Moderate 
               
               
                 6/M 
                 acid magenta 
                 guanidine 
                 slight 
                 slight 
                 slight 
               
               
                   
                 and xanthene 
               
               
                   
                 magenta 
               
               
                 Run 
                 Mixture of 
                 Poly- 
                 Immobile 
                 Immobile 
                 Immobile 
                 Slight 
                 Moderate 
               
               
                 6/Y 
                 direct yellow 
                 guanidine 
               
               
                   
                 and acid 
               
               
                   
                 yellow 
               
               
                   
               
             
          
         
       
     
       Example 3 
       [0034]    A stock solution of ink containing anionic dye, Acid Blue 9(AB9), and fixer containing cationic polymer, Polyguanidine, are diluted with ratios of water and 2-P. For steady state solubility, equal volumes of the ink solutions and the fixer solutions are mixed. Solubility is determined by examining the mixture for precipitate after 1-day at ambient conditions 
         [0035]    Stock solutions are listed in Table 3A below: 
         [0000]    
       
         
               
               
             
               
               
               
               
             
               
               
               
               
             
           
               
                 TABLE 3A 
               
             
             
               
                   
               
               
                 Ink A 
                 FIXER B 
               
             
          
           
               
                   
                 % 
                   
                 % 
               
               
                 Components 
                 active 
                 Components 
                 active 
               
               
                   
               
             
          
           
               
                 Dye AB-9 
                 6 
                 Polyguanidine 
                 4 
               
               
                 Bis(2- 
                 0.90 
                 1,2-Hexanediol 
                 7.5 
               
               
                 ethylhexyl)sulfosuccinate 
                   
                 2,3,4,5- 
                 7.5 
               
               
                 Fluorocarbon surfactant 
                 0.30 
                 Tetrahydrothiophene-1,1- 
               
               
                 4-Octylphenol 
                 0.4 
                 dioxide 
               
               
                 Polyethoxylate 
                   
                 Fluorocarbon surfactant 
                 0.3 
               
               
                 Na 2 EDTA 
                 0.2 
                 POE (4) lauryl ether 
                 0.4 
               
               
                 MOPS 
                 0.4 
                 B-Alanine 
                 0.2 
               
               
                   
                   
                 Na 2 EDTA 
                 0.05 
               
               
                   
               
             
          
         
       
     
         [0036]    Table 3B below summarizes the solubility of Ink A and the Polyguanidine Fixer at various water/2P ratios. The concentration of 2-pyrrolidone has a strong effect on the interaction of the dye and fixer. Increasing the concentration of 2-P increases the solubility of the dye/fixer complex. 
         [0000]    
       
         
               
               
               
               
               
               
             
               
               
               
               
               
             
           
               
                   
               
             
             
               
                   
                 Weight % 
                 Weight % 
                 Weight % 
                 ppt with 
                 ppt with 
               
               
                 Sample 
                 (Dye) 
                 water 
                 2P 
                 Sample X 
                 Sample Y 
               
               
                   
               
               
                 1 
                 0.60 
                 90 
                 0 
                 Yes 
                 Yes 
               
               
                 2 
                 0.60 
                 80 
                 20 
                 Yes 
                 Yes 
               
               
                 3 
                 0.60 
                 60 
                 40 
                 Yes 
                 None 
               
               
                 4 
                 0.60 
                 40 
                 60 
                 Yes 
                 None 
               
               
                 5 
                 0.60 
                 20 
                 80 
                 Yes 
                 None 
               
               
                 6 
                 0.60 
                 0 
                 90 
                 None 
                 None 
               
               
                   
               
             
          
           
               
                   
                   
                 Weight % 
                 Weight % 
                 Weight % 
               
               
                   
                 Sample 
                 (Fixer) 
                 water 
                 2P 
               
               
                   
                   
               
               
                   
                 X 
                 2 
                 98 
                 0 
               
               
                   
                 Y 
                 2 
                 48 
                 50 
               
               
                   
                   
               
             
          
         
       
     
         [0037]    In &gt;45%  2 -P, Ink A/Polyguanidine Fixer complex does not precipitate. 
       Example 4 
       [0038]    The solubility of the DB168 Dye/Polyguanidine Fixer complex was tested in various solvents. Dye and fixer were added to aqueous cosolvent solutions to attain a concentration of 9.4 g/L DB168 Dye and 9.4 g/L Polyguanidine Fixer—the resulting mixture partitions into a liquid supernatant phase and a solid precipitate phase. Entries in Table 4 below represent the % of the total colorant that goes into the supernatant phase (100% would represent complete dye/fixer solubility in a solvent). The data shows that DB168 Dye/Polyguanidine Fixer is the most soluble in 88% 2P—and that the reproducibility of this measurement is good (comparing ‘2P’ and replicate ‘2P-2’). It also shows that the relative ability of solvents to dissolve the dye/fixer complex changes as water is taken out of the system. For example, at 44% aq TMS is a better solvent for DB168 Dye/Polyguanidine Fixer than 44% aqueous TEG, but 88% aqueous TEG is a better solvent than 88% aqueous TMS. 
         [0000]    
       
         
               
               
               
             
               
               
               
               
             
           
               
                   
                   
               
               
                   
                 44% solvent 
                 88% solvent 
               
               
                   
                   
               
             
             
               
                   
               
             
          
           
               
                   
                 2-pyrrolidone 
                 0.28 
                 34.27 
               
               
                   
                 2-pyrrolidone (rep 2) 
                 0.27 
                 34.87 
               
               
                   
                 1,2-hexanediol 
                 0.11 
                 0.18 
               
               
                   
                 Tetramethylene sulfone 
                 0.38 
                 7.63 
               
               
                   
                 1-methyl-2-pyrrolidone 
                 0.45 
                 30.54 
               
               
                   
                 1,2-propanediol 
                 0.00 
                 0.67 
               
               
                   
                 Diethylene glycol 
                 0.00 
                 3.47 
               
               
                   
                 Tetraethylene glycol 
                 0.00 
                 8.86 
               
               
                   
                 Glycerol 
                 0.00 
                 0.00 
               
               
                   
                 Ethylene glycol 
                 0.00 
                 0.40 
               
               
                   
                 Tetrahydrofuran 
                 1.32 
                 15.45 
               
               
                   
                 n,n-dimethylpropionamide 
                 0.76 
                 20.30 
               
               
                   
                   
               
             
          
         
       
     
       Example 5 
       [0039]    Fixer-dye mixtures containing 0, 8, and 40% 2P were made by mixing 3% of dye in water or in 40% 2P with 3% of FA11/5 (polymonoguanidine) or FA2 (polybiguanadine) in water, pH adjusted to 4. Higher 2P-containing solutions (40% 2P in mixture) were prepared by mixing 3% dye in water with 6% FA11/5 or FA2 (in water, pH adjusted to 4) As dyes, PJ485, AB9, M364, AR289, DY132, AY23-TMA, DB19 and DB168 were used in this study. The samples were centrifuged. 
         [0040]    The “Colorant Soluble” was plotted in  FIG. 1 ,  2 ,  3  in DI water, 8% 2P and 40% 2P, respectively, where “% Colorant Soluble” is defined as absorbance at λ max  (w/o fixer). For DB168 and DB19, the minimum of “% Colorant Soluble” was reached at ˜0.5 fixer/dye ratio. There was virtually no difference observed in “% Colorant Soluble” of the fixer-black dye complexes using FA2 or FA11/5. 
         [0041]    Regardless of fixer type or % 2P present in the solution, fixer-DB168 complex is the least soluble. Fixer-DB19 complex was more soluble than fixer-DB168 complex but still less soluble than most of the fixer-color dye complexes. 
         [0042]    As shown in  FIG. 4 , “% Colorant Soluble” increased with increasing % 2P. The amount of colorant soluble increased by roughly one order of magnitude from 0 to 40% 2P for most dyes including DB19. “% Colorant Soluble” of fixer—DB168 appeared to be insensitive to 2P content in this region. 
       Example 6 
       [0043]    As in Example 1, 1 microliter anionic dye-based ink and cationic polymeric fixer is pipetted in the order Fixer/Color/Fixer for each of colors black, cyan, magenta and yellow onto cellulose thin layer chromatography (TLC) plates. The TLC plates were dried for 30 minutes at ambient temperature. The TLC plate was developed in solvent at 55° C. 
         [0044]    The table below summarizes the mobility of Run 2 dye/fixer complex/precipitates in various additional water-based servicing solvents. The dielectric constants at standard temperature and pressure are given for each of the solvents. Both “ineffective” and “effective” solvents are included on the list. The more “effective” solvents tend to occur within the range of 20-41 dielectric constant at standard temperature and pressure. 
         [0000]    
       
         
               
               
               
               
               
               
               
               
               
             
               
               
               
               
               
               
               
             
           
               
                 TABLE 6 
               
               
                   
               
               
                 Run/ 
                   
                   
                   
                 1,2- 
                 Triethylene 
                 1,5- 
                 1,4- 
                 Ethylene 
               
               
                 Ink 
                 Dye 
                 Fixer 
                 1-pentanol 
                 pentanediol 
                 glycol 
                 pentanediol 
                 butanediol 
                 glycol 
               
               
                   
               
             
             
               
                 Run 
                 Direct Black 
                 Poly- 
                 Immobile 
                 Slight 
                 Slight 
                 Immobile 
                 Very 
                 Slight 
               
               
                 2/K 
                   
                 guanidine 
                   
                   
                   
                   
                 slight 
               
               
                 Run 
                 Phthalo- 
                 Poly- 
                 Immobile 
                 Very 
                 Slight 
                 Slight 
                 Slight 
                 Moderate 
               
               
                 2/C 
                 cyanine cyan 
                 guanidine 
                   
                 slight 
               
               
                 Run 
                 H-acid 
                 Poly- 
                 Immobile 
                 Very 
                 Slight 
                 Slight 
                 Slight 
                 Moderate 
               
               
                 2/M 
                 magenta 
                 guanidine 
                   
                 slight 
               
               
                 Run 
                 Direct yellow 
                 Poly- 
                 Immobile 
                 Immobile 
                 Slight 
                 Very 
                 Slight 
                 Moderate 
               
               
                 2/Y 
                   
                 guanidine 
                   
                   
                   
                 slight 
               
             
          
           
               
                 Dielectric Constants at STP 
                 16.9 
                 17.3 
                 23.7 
                 26.2 
                 31.9 
                 41.4 
               
               
                   
               
             
          
         
       
     
         [0045]    Other embodiments of the invention will be apparent to those skilled in the art from a consideration of the specification or practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with the true scope and spirit of the invention being indicated by the following claims.