Inkjet ink composition, method for manufacturing the inkjet ink composition and image forming method using the inkjet ink composition

Abstract

A method for manufacturing a composition including: mixing a basic material with a pigment dispersion including at least a pigment and water; and then subjecting the mixture of the basic material and pigment dispersion to a heat treatment. This composition is useful as an inkjet ink composition. An inkjet ink composition including at least pigment, water and a basic material, and has a pH of from 6.5 to 11.0 is also provided. An image forming method including discharging the composition from a nozzle to form an ink image on a receiving material is provided.

1 - 16 . (canceled).  
     
     
         17 . A composition comprising: 
 at least one surface-treated pigment;    water;    at least one water-soluble organic solvent; and    a basic material,    wherein the composition has an initial pH of from 6.5 to 11.    
     
     
         18 . The composition according to  claim 17 , wherein the composition has a final pH not less than 6.5 after being heated at 70° C. for 3 weeks.  
     
     
         19 . The composition according to  claim 18 , wherein a ratio of the final pH to the initial pH is not less than 0.90.  
     
     
         20 . An image forming method comprising: 
 discharging an inkjet ink from a nozzle to form an ink image on a receiving material,    wherein the inkjet ink comprises:    at least one surface treated pigment;    at least one water-soluble organic solvent:    water; and    a basic material,    wherein the inkjet ink composition has an initial pH of from 6.5 to 11.    
     
     
         21 . The image forming method according to  claim 20 , wherein the inkjet ink has a final pH not less than 6.5 after being heated at 70° C. for 3 weeks.  
     
     
         22 . The image forming method according to  claim 21 , wherein a ratio of the final pH to the initial pH is not less than 0.90.  
     
     
         23 . An image formed on a receiving material in accordance with the method of  claim 20 .  
     
     
         24 . The composition of  claim 17 , wherein the surface-treated pigment has at least one of —COONa or —SO 3 Na groups chemically reacted with the surface of the pigment.  
     
     
         25 . An inkjet ink comprising the composition claimed in  claim 17 .  
     
     
         26 . The composition of  claim 17 , wherein the pigment is present in an amount of from 1 to 20% by weight.  
     
     
         27 . The composition of  claim 17 , further comprising at least one selected from the group consisting of lithium hydroxide, sodium hydroxide and potassium hydroxide.  
     
     
         28 . The composition of  claim 17 , comprising at least one selected from the group consisting of glycerin, diethylene glycol, and 1,2-butanediol.  
     
     
         29 . The composition of  claim 17 , wherein the solvent is present in an amount not greater than 50% by weight relative to the total weight of the composition.  
     
     
         30 . The method of  claim 20 , wherein the surface-treated pigment has at least one of —COONa or —SO 3 Na groups chemically reacted with the surface of the pigment.