Solvent-uv hybrid inkjet ink for aluminum beverage can decoration

Abstract

A hybrid inkjet ink comprising a water miscible organic solvent, a UV radiation-curable material and appropriate photoinitiator, and an epoxide-containing material and printed decorations produced by applying the inkjet ink images to an aluminum substrate.

What we claim is: 
     
         1 . A hybrid inkjet ink comprising, in percent by weight based on the weight of the ink:
 about 3-49% of a water miscible organic solvent;   about 3-80% by weight of a UV radiation-curable material and an appropriate photoinitiator; and   about 1-30% by weight of an epoxide-containing material.   
     
     
         2 . The hybrid inkjet ink of  claim 1  in which the water miscible organic solvent is chosen from the group consisting of carbonates, lactones, glycols and glycol ethers. 
     
     
         3 . The hybrid inkjet ink of  claim 1  in which the organic solvent is a lactone. 
     
     
         4 . The hybrid inkjet ink of  claim 1  in which the UV radiation-curable material is chosen from the group consisting of: a monofunctional UV radiation-curable monomer, a difunctional UV radiation-curable monomer, and a trifunctional UV radiation-curable monomer. 
     
     
         5 . The hybrid inkjet ink of  claim 4  including two or more of a monofunctional UV radiation-curable monomer, a difunctional UV radiation-curable monomer, and a trifunctional UV radiation-curable monomer. 
     
     
         6 . The hybrid inkjet ink of  claim 1  in which the UV radiation-curable material comprises all three of a monofunctional UV radiation-curable monomer, a difunctional UV radiation-curable monomer, and a trifunctional UV radiation-curable monomer. 
     
     
         7 . The hybrid inkjet ink of  claim 1  in which the UV radiation-curable material monomer is a cycloaliphatic acrylate. 
     
     
         8 . The hybrid inkjet ink of  claim 7  in which the cycloaliphatic acrylate is isobornyl acrylate and/or 4-tert-butylcyclohexylacrylate. 
     
     
         9 . The hybrid inkjet ink of  claim 1  in which the UV radiation-curable material is difunctional and is chosen from the group consisting of aliphatic, cycloaliphatic, polyester, polyurethane, and ethylene/propylene glycol diacrylates. 
     
     
         10 . The hybrid inkjet ink of  claim 9  in which the difunctional UV radiation-curable material is hexanediol diacrylate and/or diprophylene glycol diacrylate. 
     
     
         11 . The hybrid inkjet ink of  claim 1  in which the radiation-curable material is propoxylated(3)trimethylopropane triacrylate. 
     
     
         12 . The hybrid inkjet ink of  claim 1  including a resin. 
     
     
         13 . The hybrid inkjet ink of  claim 12  in which the molecular weight of the resin is less than about 100,000 Daltons. 
     
     
         14 . The hybrid inkjet ink of  claim 12  in which the molecular weight of the resin is in the range of about 1000-50,000 Daltons. 
     
     
         15 . The hybrid inkjet ink of  claim 12  in which the resin is chosen from the group consisting of polyols, acrylated polyesters, and acrylated polyurethanes. 
     
     
         16 . The hybrid inkjet ink of  claim 1  in which the epoxide-containing material is a mono-, di-, or tri-functional epoxide chosen from the group consisting of aliphatic, aromatic, saturated and unsaturated epoxides. 
     
     
         17 . The hybrid inkjet ink of  claim 1  in which the epoxy-containing material comprises cyclohexyl dimethanol diglycidyl ether and/or neopentyl glycol diglycidyl ether. 
     
     
         18 . The hybrid inkjet ink of  claim 1  including a colorant. 
     
     
         19 . The hybrid inkjet ink of  claim 18  in which the colorant is a pigment or dye in combination with a dispersant stabilized using dispersants that are compatible with the remaining components of the inkjet ink. 
     
     
         20 . A printed decoration comprising:
 an aluminum substrate; and   an ink composition applied to the aluminum substrate using an inkjet printer, where the inkjet composition comprises, based upon the total weight of the ink, about 3-49% by weight of a water miscible organic solvent, about 3-80% by weight of a UV radiation-curable material and an appropriate photoinitiator and about 1-30% by weight of an epoxide-containing material.   
     
     
         21 . A method of producing a printed decoration to an aluminum substrate comprising:
 providing an aluminum substrate;   providing an inkjet ink composition comprising, based on the total weight of the ink, about 3-49% by weight of water miscible organic solvent, about 3-80% by weight of a UV radiation-curable component, and an appropriate photoinitiator; and about 1-30% by weight of an epoxide-containing material;   applying the inkjet composition to the aluminum substrate using an inkjet printer to form an image on the substrate;   irradiating the image with UV light to achieve a partial cure of the UV curable component of the ink, pinning the image to the substrate while leaving unevaporated solvent in place within the image;   applying an overprint varnish coating to intermix with the unevaporated solvent in the image; and   heating the image to drive off the solvent and produce a full cure of the image as a decoration on the aluminum substrate.   
     
     
         22 . The method of  claim 21  in which the overprint varnish includes an aqueous carrier. 
     
     
         23 . The method of  claim 21  in which the overprint varnish includes an organic carrier. 
     
     
         24 . The method of  claim 21  in which the aluminum substrate is the outer surface of an aluminum beverage can. 
     
     
         25 . The hybrid inkjet ink of  claim 21  in which the printed decorations have a thickness exclusive of overprint varnish of about 1 to 12 μm. 
     
     
         26 . The hybrid inkjet ink of  claim 21  in which the printed decorations have a thickness exclusive of overprint varnish of about 1-8 μm.