Memjet Technology Limited

Roger Davey

Simon Fielder

Teruyuki Fukuda

Satoshi Tanaka

Adrian Peter Bisson

Iain Blake

Richard Myors

Ellaine Munton

Steven Carter

Alison Chong

Stephen Bernard

David Tyvoll

Philippa Read

Tim Hudson

An aqueous-based inkjet ink for a thermal inkjet printhead includes: a pigment; 2 to 90 ppm ammonium ions; and an ink vehicle. The ink has a pH in the range of 8 to 9.5 and exhibits improved lifetime in thermal inkjet printheads with minimal loss of print quality.

Pigment-based ink formulations having improved printhead lifetime

A method of inkjet printing includes the steps of: printing a first ink onto a print medium, the first ink including a first self-dispersible pigment, the first ink having a first pigment content A; and subsequently printing a second ink onto the print medium at least partially over the first ink, the second ink including a second pigment and a polymeric dispersant encapsulating the second pigment, the second ink having a second pigment content B. The first self-dispersible pigment and the second pigment have a same color; the pigment content A of the first ink and the pigment content B of the overprinted second ink have a relationship 0.8&#x2266;A/B&#x2266;1.2; and a polymer acid value of the polymeric dispersant is in the range of 100 to 170.

Method of printing pigment-based inks including ink sets, inks and printers therefor

Growing community of inventors

Sydney, Australia

Roger Davey