Abstract: The present invention provides a pigment ink formulation containing a wax emulsion is disclosed. The wax emulsion comprises a specific wax and surfactant combination. In particular, the wax comprises a linear polyethylene wax and the surfactant is an alkyl ether carboxylate. The wax emulsion can be made by any process for preparing emulsions used by those skilled in the art such as typical homogenization methods. Applicants have discovered that such a wax emulsion can not only improve the scratch resistance of pigmented ink, but also improve other handling problems such as scuff and smear.

Abstract: The present invention provides an aqueous ink containing ?3% silver particles having improved jetting performance which can be used reliably for printing of silver traces to obtain desired conductivity on printed media. The humectant (cosolvent) type/loading and surfactant type/loading described herein prevents nozzle drop outs or clogs for a long period of time without an extensive maintenance which is normally required for high solid inks. In a preferred embodiment, the present invention provides silver ink formulation containing humectant mixture of 5-15% 1,2-propanediol and 5-15% of glycol ethers compound with the following structure: R—[OCH2CH2]n—OH wherein R is a C1-C4 alkyl group and n is 1 to 3. A preferred surfactant is ethoxylated 2,4,7,9-tetramethyl 5 decyn-4,7-diol.