Water-Based Inks for Ink-Jet Printing

Abstract

The present invention relates to a water-based ink for ink-jet printing which not only satisfies a high optical density but also exhibits an excellent high lighter-fastness; a water dispersion used for the water-based ink; and a method for producing a print using the water-based ink. There are provided a water dispersion for ink-jet printing comprising (i) (A-1) polymer particles containing a colorant, (B) polymer particles and (C) the water-insoluble organic compound, or (ii) (A-2) self-dispersible pigment, (B) polymer particles and (C) the water-insoluble organic compound; a water-based ink containing the water dispersion; and a method for producing a print using the water-based ink.

1 : A water dispersion for ink-jet printing comprising (A-1) polymer particles containing an colorant (B) polymer particles and (C) a water-insoluble organic compound.  
     
     
         2 : A water dispersion for ink-jet printing comprising (A-2) self-dispersible pigment (B) polymer particles and (C) a water-insoluble organic compound.  
     
     
         3 : The water dispersion for ink-jet printing according to  claim 1 , wherein the polymer particles (B) are self-emulsifiable polymer particles containing a constitutional unit derived from a salt-forming group-containing monomer.  
     
     
         4 : The water dispersion for ink-jet printing according to  claim 1 , wherein the polymer particles (B) are polymer particles produced by emulsion-polymerizing an ethylenically unsaturated monomer in the presence of a reactive surfactant.  
     
     
         5 : The water dispersion for ink-jet printing according to  claim 1 , wherein the water-insoluble organic compound (C) is an ester or ether compound (f) containing two or more ester or ether bonds in a molecule thereof, and/or an ester or ether compound (g) containing one or more ester or ether bonds and at east one functional group selected from the group consisting of a carboxyl group, a sulfonic group, a phosphoric acid residue, a carbonyl group, an epoxy group and a hydroxyl group.  
     
     
         6 : The water dispersion for ink-jet printing according to  claim 1 , wherein the water-insoluble organic compound (C) is at least one compound selected from the group consisting of phosphoric esters, aliphatic di- or tri-carboxylic esters and glyceryl alkyl ethers.  
     
     
         7 : The water dispersion for ink-jet printing according to  claim 1 , wherein the water-insoluble organic compound (C) has a Log P value of from −1 to 11.  
     
     
         8 : The water dispersion for ink-jet printing according to  claim 1 , wherein a content of the water-insoluble compound (C) in the water dispersion is from 0.4 to 10% by weight.  
     
     
         9 : The water dispersion for ink-jet printing according to  claim 1 , wherein a weight ratio of the polymer particles (B) to the water-insoluble organic compound (C) is from 15/1 to 1/2.  
     
     
         10 : A water-based ink for ink-jet printing comprising the water dispersion as defined in  claim 1 .  
     
     
         11 : A method for producing a print, comprising the step of printing images or characters with the water-based ink as defined in  claim 10 , on an ordinary paper by an ink-jet printing method.  
     
     
         12 : The water dispersion for ink-jet printing according to  claim 2 , wherein the polymer particles (B) are self-emulsifiable polymer particles containing a constitutional unit derived from a salt-forming group-containing monomer.  
     
     
         13 : The water dispersion for ink-jet printing according to  claim 2 , wherein the polymer particles (B) are polymer particles produced by emulsion-polymerizing an ethylenically unsaturated monomer in the presence of a reactive surfactant.  
     
     
         14 : The water dispersion for ink-et printing according t  claim 2 , wherein the water-insoluble organic compound (C) is an ester or ether compound (f) containing two or more ester or ether bonds in a molecule thereof, and/or an ester or ether compound (g) containing one or more ester or ether bonds and at least one functional group selected from the group consisting of a carboxyl group, a sulfonic group, a phosphoric acid residue, a carbonyl group, an epoxy group and a hydroxyl group.  
     
     
         15 : The water dispersion for ink-jet printing according to  claim 2 , wherein the water-insoluble organic compound (C) is at least one compound selected from the group consisting of phosphoric esters, aliphatic di- or tri-carboxylic esters and glyceryl alkyl ethers.  
     
     
         16 : The water dispersion for ink-jet printing according to  claim 2 , wherein the water-insoluble organic compound (C) has a Log P value of from −1 to 11.  
     
     
         17 : The water dispersion for ink-jet printing according to  claim 2 , wherein a content of the water-insoluble compound (C) in the water dispersion is from 0.4 to 10% by weight.  
     
     
         18 : The water dispersion for ink-jet printing according to  claim 2  wherein a weight ratio of the polymer particles (B) to the water-insoluble organic compound (C) is from 15/1 to 1/2.  
     
     
         19 : A water-based ink for ink-jet printing comprising the water dispersion as defined in  claim 2 .  
     
     
         20 : A method for producing a print comprising the step of printing images or characters with the water-based ink as defined in  claim 19 , on an ordinary paper by an ink-jet printing method.