Inkjet ink

Abstract

According to one embodiment, an inkjet ink includes a non-conductive metal pigment, a resin, and a solvent, and the surface of the non-conductive metal pigment is coated with an alkoxide including an alkoxysilane, and the coating film has a crosslinked structure.

What is claimed is: 
     
         1 . An inkjet ink, comprising
 an organic solvent as an ink vehicle, the organic solvent containing no active hydrogen and accounting for 84 mass % or more of the ink;   a resin; and   a non-conductive metal pigment which has an electrical conductivity of 10 −13  (Ω·cm) −1  or less and which has a metal pigment and a coating film covering the metal pigment, the coating film being made of at least one of the group consisting of an alkoxysilane represented by the general formula (1) and an organoalkoxysilane represented by the general formula (2), and having a crosslinked structure,   
       
         
           
           
               
               
           
         
         wherein R represents an alkyl group having 1 to 4 carbon atoms, and n represents a number of 1 to 20,
   R 1 R 2   a —Si—(OR 3 ) 3-a   (2)
 
 
         wherein R 1  represents a monovalent group having a hydrogen atom or a functional group selected from an alkyl group, an alkenyl group, a glycidoxy group, an epoxycycloalkyl group having 5 or 6 carbon atoms, a (meth)acryl group, an amino group, a mercapto group, and an isocyanate group; R 2  represents a group selected from an alkyl group having 1 to 4 carbon atoms and a phenyl group; R 3  represents a monovalent alkyl group having 1 to 4 carbon atoms; and a represents 0, 1, or 2. 
       
     
     
         2 . The ink according to  claim 1 , wherein the organic solvent is at least one organic solvent selected from a group consisting of an aliphatic hydrocarbon, an aromatic hydrocarbon, a halogenated hydrocarbon, an organic acid ester, an ether, and a ketone. 
     
     
         3 . The ink according to  claim 1 , wherein the non-conductive metal pigment is a metal composed mainly of aluminum. 
     
     
         4 . The ink according to  claim 1 , wherein the non-conductive metal pigment has a scaly shape. 
     
     
         5 . The ink according to  claim 1 , wherein the average particle diameter of the non-conductive metal pigment is 0.4 or more and less than 0.95 μm. 
     
     
         6 . The ink according to  claim 1 , wherein the resin is at least one resin selected from an acrylic resin, a polyester resin, a phenolic resin, a polyamide, polyvinyl butyral, cellulose acetate butyrate, a nitrocellulose resin, a polyurethane, a vinyl chloride-vinyl acetate copolymer, and a resin emulsion thereof. 
     
     
         7 . The ink according to  claim 1 , wherein the addition amount of the resin is from 0.3 mass % to 1 mass %. 
     
     
         8 . The ink according to  claim 1 , wherein the addition amount of the non-conductive metal pigment is at least 0.5 mass % or more. 
     
     
         9 . The ink according to  claim 1 , wherein the ratio of the addition amount of the resin to that of the non-conductive metal pigment is from 0.3 to 1 part with respect to 1 part of the pigment.